Fisher information, kinetic energy and uncertainty relation inequalities
International Nuclear Information System (INIS)
Luo Shunlong
2002-01-01
By interpolating between Fisher information and mechanical kinetic energy, we introduce a general notion of kinetic energy with respect to a parameter of Schroedinger wavefunctions from a statistical inference perspective. Kinetic energy is the sum of Fisher information and an integral of a parametrized analogue of quantum mechanical current density related to phase. A family of integral inequalities concerning kinetic energy and moments are established, among which the Cramer-Rao inequality and the Weyl-Heisenberg inequality, are special cases. In particular, the integral inequalities involving the negative order moments are relevant to the study of electron systems. Moreover, by specifying the parameter to a scale, we obtain a family of inequalities of uncertainty relation type which incorporate the position and momentum observables symmetrically in a single quantity. (author)
International Nuclear Information System (INIS)
March, N.H.
2002-08-01
In early work, Dawson and March [J. Chem. Phys. 81, 5850 (1984)] proposed a local energy method for treating both Hartree-Fock and correlated electron theory. Here, an exactly solvable model two-electron atom with pure harmonic interactions is treated in its ground state in the above context. A functional relation between the kinetic energy density t(r) at the origin r=0 and the electron density p(r) at the same point then emerges. The same approach is applied to the Hookean atom; in which the two electrons repel with Coulombic energy e 2 /r 12 , with r 12 the interelectronic separation, but are still harmonically confined. Again the kinetic energy density t(r) is the focal point, but now generalization away from r=0 is also effected. Finally, brief comments are added about He-like atomic ions in the limit of large atomic number. (author)
A Comparison of Kinetic Energy and Momentum in Special Relativity and Classical Mechanics
Riggs, Peter J.
2016-01-01
Kinetic energy and momentum are indispensable dynamical quantities in both the special theory of relativity and in classical mechanics. Although momentum and kinetic energy are central to understanding dynamics, the differences between their relativistic and classical notions have not always received adequate treatment in undergraduate teaching.…
Galilean Relativity and the Work-Kinetic Energy Theorem
Tefft, Brandon J.; Tefft, James A.
2007-01-01
As the topic of relativity is developed in a first-year physics class, there seems to be a tendency to move as quickly as possible to the fascinating ideas set forth in Einstein's special theory of relativity. In this paper we linger a little with the Galilean side of relativity and discuss an intriguing problem and its solution to illustrate a…
Indian Academy of Sciences (India)
Abstract. This paper presents the detailed turbulent kinetic energy budget and higher order statistics of flow behind a surface-mounted rib with and without superimposed acoustic excitation. Pattern recognition technique is used to determine the large-scale structure magnitude. It is observed that most of the turbulence ...
International Nuclear Information System (INIS)
Bricmont, R.J.; Hamilton, P.A.; Ming Long Ting, R.
1981-01-01
Reactors, fuel processing plants etc incorporate pipes and conduits for fluids under high pressure. Fractures, particularly adjacent to conduit elbows, produce a jet of liquid which whips the broken conduit at an extremely high velocity. An enormous impact load would be applied to any stationary object in the conduit's path. The design of cellular, corrugated metal impact pads to absorb the kinetic energy of the high velocity conduits is given. (U.K.)
International Nuclear Information System (INIS)
March, Norman H.; Akbari, Ali; Rubio, Angel
2007-01-01
For arbitrary interparticle interaction u(r 12 ), the model two-electron atom in the title is shown to be such that the ground-state electron density ρ(r) is determined uniquely by the correlated kinetic energy density t R (r) of the relative motion. Explicit results for t R (r) are presented for the Hookean atom with force constant k=1/4, and also for u(r 12 )=(λ)/(r 12 2 ) . Possible relevance of the Hookean atom treatment to the ground state of the helium atom itself is briefly discussed
Energy Technology Data Exchange (ETDEWEB)
Jaeggi, M.; Folini, P.
1983-09-03
A flywheel system for the purpose of energy storage in decentral solar- or wind energy plants is introduced. The system comprises a rotor made out of plastic fibre, a motor/generator serving as electro-mechanical energy converter and a frequency-voltage transformer serving as electric adapter. The storable energy quantity amounts to several kWh.
International Nuclear Information System (INIS)
Lombard, R.J.; Mas, D.; Moszkowski, S.A.
1991-01-01
We discuss two expressions for the density of kinetic energy which differ by an integration by parts. Using the Wigner transform we shown that the arithmetic mean of these two terms is closely analogous to the classical value. Harmonic oscillator wavefunctions are used to illustrate the radial dependence of these expressions. We study the differences they induce through effective mass terms when performing self-consistent calculations. (author)
Concepts of radial and angular kinetic energies
DEFF Research Database (Denmark)
Dahl, Jens Peder; Schleich, W.P.
2002-01-01
We consider a general central-field system in D dimensions and show that the division of the kinetic energy into radial and angular parts proceeds differently in the wave-function picture and the Weyl-Wigner phase-space picture, Thus, the radial and angular kinetic energies are different quantities...
Li, Yang; Klippenstein, Stephen J; Zhou, Chong-Wen; Curran, Henry J
2017-10-12
The oxidation chemistry of the simplest conjugated hydrocarbon, 1,3-butadiene, can provide a first step in understanding the role of polyunsaturated hydrocarbons in combustion and, in particular, an understanding of their contribution toward soot formation. On the basis of our previous work on propene and the butene isomers (1-, 2-, and isobutene), it was found that the reaction kinetics of Ḣ-atom addition to the C═C double bond plays a significant role in fuel consumption kinetics and influences the predictions of high-temperature ignition delay times, product species concentrations, and flame speed measurements. In this study, the rate constants and thermodynamic properties for Ḣ-atom addition to 1,3-butadiene and related reactions on the Ċ 4 H 7 potential energy surface have been calculated using two different series of quantum chemical methods and two different kinetic codes. Excellent agreement is obtained between the two different kinetics codes. The calculated results including zero-point energies, single-point energies, rate constants, barrier heights, and thermochemistry are systematically compared among the two quantum chemical methods. 1-Methylallyl (Ċ 4 H 7 1-3) and 3-buten-1-yl (Ċ 4 H 7 1-4) radicals and C 2 H 4 + Ċ 2 H 3 are found to be the most important channels and reactivity-promoting products, respectively. We calculated that terminal addition is dominant (>80%) compared to internal Ḣ-atom addition at all temperatures in the range 298-2000 K. However, this dominance decreases with increasing temperature. The calculated rate constants for the bimolecular reaction C 4 H 6 + Ḣ → products and C 2 H 4 + Ċ 2 H 3 → products are in excellent agreement with both experimental and theoretical results from the literature. For selected C 4 species, the calculated thermochemical values are also in good agreement with literature data. In addition, the rate constants for H atom abstraction by Ḣ atoms have also been calculated, and it is
Energy Technology Data Exchange (ETDEWEB)
Dehesa, J S [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, 18071-Granada (Spain); Gonzalez-Ferez, R [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, 18071-Granada (Spain); Sanchez-Moreno, P [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, 18071-Granada (Spain)
2007-02-23
The inequality
>= (l+1/2){sup 2}
Kinetic energy principle and neoclassical toroidal torque in tokamaks
International Nuclear Information System (INIS)
Park, Jong-Kyu
2011-01-01
It is shown that when tokamaks are perturbed, the kinetic energy principle is closely related to the neoclassical toroidal torque by the action invariance of particles. Especially when tokamaks are perturbed from scalar pressure equilibria, the imaginary part of the potential energy in the kinetic energy principle is equivalent to the toroidal torque by the neoclassical toroidal viscosity. A unified description therefore should be made for both physics. It is also shown in this case that the potential energy operator can be self-adjoint and thus the stability calculation can be simplified by minimizing the potential energy.
Nanostructured energy devices equilibrium concepts and kinetics
Bisquert, Juan
2014-01-01
Due to the pressing needs of society, low cost materials for energy devices have experienced an outstanding development in recent times. In this highly multidisciplinary area, chemistry, material science, physics, and electrochemistry meet to develop new materials and devices that perform required energy conversion and storage processes with high efficiency, adequate capabilities for required applications, and low production cost. Nanostructured Energy Devices: Equilibrium Concepts and Kinetics introduces the main physicochemical principles that govern the operation of energy devices. It inclu
Alternative kinetic energy metrics for Lagrangian systems
Sarlet, W.; Prince, G.
2010-11-01
We examine Lagrangian systems on \\ {R}^n with standard kinetic energy terms for the possibility of additional, alternative Lagrangians with kinetic energy metrics different to the Euclidean one. Using the techniques of the inverse problem in the calculus of variations we find necessary and sufficient conditions for the existence of such Lagrangians. We illustrate the problem in two and three dimensions with quadratic and cubic potentials. As an aside we show that the well-known anomalous Lagrangians for the Coulomb problem can be removed by switching on a magnetic field, providing an appealing resolution of the ambiguous quantizations of the hydrogen atom.
Nonlocal kinetic-energy-density functionals
International Nuclear Information System (INIS)
Garcia-Gonzalez, P.; Alvarellos, J.E.; Chacon, E.
1996-01-01
In this paper we present nonlocal kinetic-energy functionals T[n] within the average density approximation (ADA) framework, which do not require any extra input when applied to any electron system and recover the exact kinetic energy and the linear response function of a homogeneous system. In contrast with previous ADA functionals, these present good behavior of the long-range tail of the exact weight function. The averaging procedure for the kinetic functional (averaging the Fermi momentum of the electron gas, instead of averaging the electron density) leads to a functional without numerical difficulties in the calculation of extended systems, and it gives excellent results when applied to atoms and jellium surfaces. copyright 1996 The American Physical Society
Temperatures of fragment kinetic energy spectra
International Nuclear Information System (INIS)
Bauer, W.
1995-01-01
Multifragmentation reactions without large compression in the initial state (proton-induced reactions, reverse kinematics, projectile fragmentation) are examined, and it is verified quantitatively that the high temperatures obtained from fragment kinetic energy spectra and lower temperatures obtained from observables such as level population or isotope ratios can be understood in a common framework
Aircraft Measurements of Atmospheric Kinetic Energy Spectra
DEFF Research Database (Denmark)
Lundtang Petersen, Erik; Lilly, D. K.
1983-01-01
Wind velocity data obtained from a jet airliner are used to construct kinetic energy spectra over the range of wavelengths from 2.5 to 2500 km. The spectra exhibit an approximate -5/3 slope for wavelengths of less than about 150 km, steepening to about -2.2 at larger scales. These results support...
Kinetic energy recovery and power management for hybrid electric vehicles
Suntharalingam, P
2011-01-01
The major contribution of the work presented in this thesis is a thorough investigation of the constraints on regenerative braking and kinetic energy recovery enhancement for electric/hybrid electric vehicles during braking. Regenerative braking systems provide an opportunity to recycle the braking energy, which is otherwise dissipated as heat in the brake pads. However, braking energy harnessing is a relatively new concept in the automotive sector which still requires further research and de...
Energy transfer and kinetics in mechanochemistry.
Chen, Zhiliang; Lu, Shengyong; Mao, Qiongjing; Buekens, Alfons; Wang, Yuting; Yan, Jianhua
2017-11-01
Mechanochemistry (MC) exerts extraordinary degradation and decomposition effects on many chlorinated, brominated, and even fluorinated persistent organic pollutants (POPs). However, its application is still limited by inadequate study of its reaction kinetic aspects. In the present work, the ball motion and energy transfer in planetary ball mill are investigated in some detail. Almost all milling parameters are summarised in a single factor-total effective impact energy. Furthermore, the MC kinetic between calcium oxide/Al and hexachlorobenzene is well established and modelled. The results indicate that total effective impact energy and reagent ratio are the two factors sufficient for describing the MC degradation degree of POPs. The reaction rate constant only depends on the chemical properties of reactants, so it could be used as an important index to appraise the quality of MC additives. This model successfully predicts the reaction rate for different operating conditions, indicating that it could be suitably applied for conducting MC reactions in other reactors.
Mass, Momentum and Kinetic Energy of a Relativistic Particle
Zanchini, Enzo
2010-01-01
A rigorous definition of mass in special relativity, proposed in a recent paper, is recalled and employed to obtain simple and rigorous deductions of the expressions of momentum and kinetic energy for a relativistic particle. The whole logical framework appears as the natural extension of the classical one. Only the first, second and third laws of…
Pairing-induced kinetic energy lowering in doped antiferromagnets
International Nuclear Information System (INIS)
Wrobel, P; Eder, R; Fulde, P
2003-01-01
We analyse lowering of the kinetic energy in doped antiferromagnets at the transition to the superconducting state. Measurements of optical conductivity indicate that such unconventional behaviour takes place in underdoped Bi-2212. We argue that the definition of the operator representing the kinetic energy is determined by experimental conditions. The thermodynamic average of that operator is related to the integrated spectral weight of the optical conductivity and thus depends on the cut-off frequency limiting that integral. If the upper limit of the integral lies below the charge transfer gap the spectral weight represents the average of the hopping term in the space restricted to the energy range below the gap. We show that the kinetic energy is indeed lowered at the superconducting transition in the t-J model (tJM), which is an effective model defined in the restricted space. That result is in agreement with experimental observations and may be attributed to the formation of spin polarons and the change of roles which are played by the kinetic and the potential energy in the tJM and in some effective model for spin polarons. The total spectral weight represents the kinetic energy in a model defined in a broader space if the upper limit in the integral of the optical conductivity is set above the gap. We demonstrate that the kinetic energy in the Hubbard model is also lowered in the superconducting state. That result does not agree with experimental observations, indicating that the spectral weight is conserved for all temperatures if the upper limit of the integral is set above the charge transfer gap. This discrepancy suggests that a single band model is not capable of describing in some respects the physics of excitations across the gap
Imperfect dark energy from kinetic gravity braiding
Energy Technology Data Exchange (ETDEWEB)
Deffayet, Cédric [AstroParticule and Cosmologie, UMR7164-CNRS, Université Denis Diderot-Paris 7, CEA, Observatoire de Paris, 10 rue Alice Domon et Léonie Duquet, F-75205 Paris Cedex 13 (France); Pujolàs, Oriol [CERN, Theory Division, CH-1211 Geneva 23 (Switzerland); Sawicki, Ignacy; Vikman, Alexander, E-mail: deffayet@iap.fr, E-mail: oriol.pujolas@cern.ch, E-mail: ignacy.sawicki@nyu.edu, E-mail: alexander.vikman@nyu.edu [Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States)
2010-10-01
We introduce a large class of scalar-tensor models with interactions containing the second derivatives of the scalar field but not leading to additional degrees of freedom. These models exhibit peculiar features, such as an essential mixing of scalar and tensor kinetic terms, which we have named kinetic braiding. This braiding causes the scalar stress tensor to deviate from the perfect-fluid form. Cosmology in these models possesses a rich phenomenology, even in the limit where the scalar is an exact Goldstone boson. Generically, there are attractor solutions where the scalar monitors the behaviour of external matter. Because of the kinetic braiding, the position of the attractor depends both on the form of the Lagrangian and on the external energy density. The late-time asymptotic of these cosmologies is a de Sitter state. The scalar can exhibit phantom behaviour and is able to cross the phantom divide with neither ghosts nor gradient instabilities. These features provide a new class of models for Dark Energy. As an example, we study in detail a simple one-parameter model. The possible observational signatures of this model include a sizeable Early Dark Energy and a specific equation of state evolving into the final de-Sitter state from a healthy phantom regime.
Imperfect dark energy from kinetic gravity braiding
International Nuclear Information System (INIS)
Deffayet, Cédric; Pujolàs, Oriol; Sawicki, Ignacy; Vikman, Alexander
2010-01-01
We introduce a large class of scalar-tensor models with interactions containing the second derivatives of the scalar field but not leading to additional degrees of freedom. These models exhibit peculiar features, such as an essential mixing of scalar and tensor kinetic terms, which we have named kinetic braiding. This braiding causes the scalar stress tensor to deviate from the perfect-fluid form. Cosmology in these models possesses a rich phenomenology, even in the limit where the scalar is an exact Goldstone boson. Generically, there are attractor solutions where the scalar monitors the behaviour of external matter. Because of the kinetic braiding, the position of the attractor depends both on the form of the Lagrangian and on the external energy density. The late-time asymptotic of these cosmologies is a de Sitter state. The scalar can exhibit phantom behaviour and is able to cross the phantom divide with neither ghosts nor gradient instabilities. These features provide a new class of models for Dark Energy. As an example, we study in detail a simple one-parameter model. The possible observational signatures of this model include a sizeable Early Dark Energy and a specific equation of state evolving into the final de-Sitter state from a healthy phantom regime
Tandem mass spectrometry at low kinetic energy
International Nuclear Information System (INIS)
Cooks, R.G.; Hand, O.W.
1987-01-01
Recent progress in mass spectrometry, as applied to molecular analysis, is reviewed with emphasis on tandem mass spectrometry. Tandem instruments use multiple analyzers (sector magnets, quadrupole mass filters and time-of-flight devices) to select particular molecules in ionic form, react them in the gas-phase and then record the mass, momenta or kinetic energies of their products. The capabilities of tandem mass spectrometry for identification of individual molecules or particular classes of compounds in complex mixtures are illustrated. Several different types of experiments can be run using a tandem mass spectrometer; all share the feature of sifting the molecular mixture being analyzed on the basis of chemical properties expressed in terms of ionic mass, kinetic energy or charge state. Applications of mass spectrometry to biological problems often depend upon desorption methods of ionization in which samples are bombarded with particle beams. Evaporation of preformed charged species from the condensed phase into the vacuum is a particularly effective method of ionization. It is suggested that the use of accelerator mass spectrometers be extended to include problems of molecular analysis. In such experiments, low energy tandem mass spectrometry conducted in the eV or keV range of energies, would be followed by further characterization of the production ion beam using high selective MeV collision processes
Kinetic energy recovery systems in motor vehicles
Śliwiński, C.
2016-09-01
The article draws attention to the increasing environmental pollution caused by the development of vehicle transport and motorization. Different types of design solutions used in vehicles for the reduction of fuel consumption, and thereby emission of toxic gasses into the atmosphere, were specified. Historical design solutions concerning energy recovery devices in mechanical vehicles which used flywheels to accumulate kinetic energy were shown. Developmental tendencies in the area of vehicle manufacturing in the form of hybrid electric and electric devices were discussed. Furthermore, designs of energy recovery devices with electrical energy storage from the vehicle braking and shock absorbing systems were presented. A mechanical energy storing device using a flywheel operating under vacuum was presented, as were advantages and disadvantages of both systems, the limitations they impose on individual constructions and safety issues. The paper also discusses a design concept of an energy recovery device in mechanical vehicles which uses torsion springs as the main components of energy accumulation during braking. The desirability of a cooperation of both the mechanical- and electrical energy recovery devices was indicated.
Redistribution of Kinetic Energy in Turbulent Flows
Directory of Open Access Journals (Sweden)
Alain Pumir
2014-10-01
Full Text Available In statistically homogeneous turbulent flows, pressure forces provide the main mechanism to redistribute kinetic energy among fluid elements, without net contribution to the overall energy budget. This holds true in both two-dimensional (2D and three-dimensional (3D flows, which show fundamentally different physics. As we demonstrate here, pressure forces act on fluid elements very differently in these two cases. We find in numerical simulations that in 3D pressure forces strongly accelerate the fastest fluid elements, and that in 2D this effect is absent. In 3D turbulence, our findings put forward a mechanism for a possibly singular buildup of energy, and thus may shed new light on the smoothness problem of the solution of the Navier-Stokes equation in 3D.
The eddy kinetic energy budget in the Red Sea
Zhan, Peng
2016-06-09
The budget of eddy kinetic energy (EKE) in the Red Sea, including the sources, redistributions and sink, is examined using a high-resolution eddy-resolving ocean circulation model. A pronounced seasonally varying EKE is identified, with its maximum intensity occurring in winter, and the strongest EKE is captured mainly in the central and northern basins within the upper 200 m. Eddies acquire kinetic energy from conversion of eddy available potential energy (EPE), from transfer of mean kinetic energy (MKE), and from direct generation due to time-varying (turbulent) wind stress, the first of which contributes predominantly to the majority of the EKE. The EPE-to-EKE conversion occurs almost in the entire basin, while the MKE-to-EKE transfer appears mainly along the shelf boundary of the basin (200 miso-bath) where high horizontal shear interacts with topography. The EKE generated by the turbulent wind stress is relatively small and limited to the southern basin. All these processes are intensified during winter, when the rate of energy conversion is about four to five times larger than that in summer. The EKE is redistributed by the vertical and horizontal divergence of energy flux and the advection of the mean flow. As a main sink of EKE, dissipation processes is ubiquitously found in the basin. The seasonal variability of these energy conversion terms can explain the significant seasonality of eddy activities in the Red Sea. This article is protected by copyright. All rights reserved.
Imperfect Dark Energy from Kinetic Gravity Braiding
Deffayet, Cedric; Sawicki, Ignacy; Vikman, Alexander
2010-01-01
We introduce a large class of scalar-tensor models with interactions containing the second derivatives of the scalar field but not leading to additional degrees of freedom. These models exhibit peculiar features, such as an essential mixing of scalar and tensor kinetic terms, which we have named kinetic braiding. This braiding causes the scalar stress tensor to deviate from the perfect-fluid form. Cosmology in these models possesses a rich phenomenology, even in the limit where the scalar is an exact Goldstone boson. Generically, there are attractor solutions where the scalar monitors the behaviour of external matter. Because of the kinetic braiding, the position of the attractor depends both on the form of the Lagrangian and on the external energy density. The late-time asymptotic of these cosmologies is a de Sitter state. The scalar can exhibit phantom behaviour and is able to cross the phantom divide with neither ghosts nor gradient instabilities. These features provide a new class of models for Dark Energ...
Kinetic energy factors in evaluation of athletes.
Jones, Jason N; Priest, Joe W; Marble, Daniel K
2008-11-01
It is established that speed and agility are critical attributes of sports performance. Performance timing of runs during agility course testing can be used to estimate acceleration, speed, or quickness. The authors of this research effort also report the energy of motion, or kinetic energy of the athlete, which considers not only the speed but also the mass of the athlete. An electronic timer was used to determine total run times as well as split performance times during a new 60-yd "run-shuttle" test. This newly designed agility test takes advantage of the technological capabilities of a laser timing device. Separate times for each of four run segments were recorded and converted to average speeds (m x s(-1)) as well as a quantitative factor of merit defined as the "K-factor." The purpose of this study was to describe the effects of training and to compare athletes and teams using measures of time, speed, and kinetic energy. Results of the analysis of total time on the 60-yd run-shuttle provided evidence of the effectiveness of the training programs. Split times of segments within the 60-yd run-shuttle provided information not available from conventional agility tests. Average speeds and K-factors identified discriminating characteristics of otherwise similar athletes. Our findings support the conclusion that training programs and athletic performance may be evaluated using the 60-yd run-shuttle with laser timer system. Coaches and trainers may find practical application of this technology for American football, soccer, basketball, baseball/softball, track and field, and field hockey.
Nonlocal kinetic energy functionals by functional integration
Mi, Wenhui; Genova, Alessandro; Pavanello, Michele
2018-05-01
Since the seminal studies of Thomas and Fermi, researchers in the Density-Functional Theory (DFT) community are searching for accurate electron density functionals. Arguably, the toughest functional to approximate is the noninteracting kinetic energy, Ts[ρ], the subject of this work. The typical paradigm is to first approximate the energy functional and then take its functional derivative, δ/Ts[ρ ] δ ρ (r ) , yielding a potential that can be used in orbital-free DFT or subsystem DFT simulations. Here, this paradigm is challenged by constructing the potential from the second-functional derivative via functional integration. A new nonlocal functional for Ts[ρ] is prescribed [which we dub Mi-Genova-Pavanello (MGP)] having a density independent kernel. MGP is constructed to satisfy three exact conditions: (1) a nonzero "Kinetic electron" arising from a nonzero exchange hole; (2) the second functional derivative must reduce to the inverse Lindhard function in the limit of homogenous densities; (3) the potential is derived from functional integration of the second functional derivative. Pilot calculations show that MGP is capable of reproducing accurate equilibrium volumes, bulk moduli, total energy, and electron densities for metallic (body-centered cubic, face-centered cubic) and semiconducting (crystal diamond) phases of silicon as well as of III-V semiconductors. The MGP functional is found to be numerically stable typically reaching self-consistency within 12 iterations of a truncated Newton minimization algorithm. MGP's computational cost and memory requirements are low and comparable to the Wang-Teter nonlocal functional or any generalized gradient approximation functional.
Turbulence generation through intense kinetic energy sources
Maqui, Agustin F.; Donzis, Diego A.
2016-06-01
Direct numerical simulations (DNS) are used to systematically study the development and establishment of turbulence when the flow is initialized with concentrated regions of intense kinetic energy. This resembles both active and passive grids which have been extensively used to generate and study turbulence in laboratories at different Reynolds numbers and with different characteristics, such as the degree of isotropy and homogeneity. A large DNS database was generated covering a wide range of initial conditions with a focus on perturbations with some directional preference, a condition found in active jet grids and passive grids passed through a contraction as well as a new type of active grid inspired by the experimental use of lasers to photo-excite the molecules that comprise the fluid. The DNS database is used to assert under what conditions the flow becomes turbulent and if so, the time required for this to occur. We identify a natural time scale of the problem which indicates the onset of turbulence and a single Reynolds number based exclusively on initial conditions which controls the evolution of the flow. It is found that a minimum Reynolds number is needed for the flow to evolve towards fully developed turbulence. An extensive analysis of single and two point statistics, velocity as well as spectral dynamics and anisotropy measures is presented to characterize the evolution of the flow towards realistic turbulence.
Digital Repository Service at National Institute of Oceanography (India)
Murty, V.S.N.; Savin, M.; RameshBabu, V.; Suryanarayana, A.
apart, indicates the existence of anticyclonic gyral circulation. The depth variation of kinetic energy (KE) emphasises the bottom intensification of currents with minimum KE at deeper depths followed by relatively higher KE at abyssal depths...
Kinetic energy dissipation in heavy-ion collisions
International Nuclear Information System (INIS)
Fedotov, S.I.; Jolos, R.V.; Kartavenko, V.G.
1979-01-01
Kinetic energy dissipation mechanism is considered in deep inelastic heavy-ion collisions. It is shown that the significant part of the kinetic energy loss can be explained by the excitation of the nuclear matter multipole vibrations. The main contribution of the energy dissipation is given by the time dependent heavy-ion interaction potential renormalized due to the nuclear excitations, rather than by the velocity proportional frictional forces
International Nuclear Information System (INIS)
Blais, N.; Podgorsak, E.B.
1992-01-01
A method for determining the kinetic energy of clinical electron beams is described, based on the measurement in air of the spatial spread of a pencil electron beam which is produced from the broad clinical electron beam. As predicted by the Fermi-Eyges theory, the dose distribution measured in air on a plane, perpendicular to the incident direction of the initial pencil electron beam, is Gaussian. The square of its spatial spread is related to the mass angular scattering power which in turn is related to the kinetic energy of the electron beam. The measured spatial spread may thus be used to determine the mass angular scattering power, which is then used to determine the kinetic energy of the electron beam from the known relationship between mass angular scattering power and kinetic energy. Energies obtained with the mass angular scattering power method agree with those obtained with the electron range method. (author)
International Nuclear Information System (INIS)
Rabia, M.A.; Fahmy, M.A.
1992-01-01
The kinetic energy released during seven unimolecular ionic transitions, generated from benzyl alcohol and benzyl amine have been studied as a function of ion source temperature and ionizing electron energy. Only, the kinetic energy released during H CN elimination from fragment [C 7 H 8 N]+ ion of benzyl amine displays a temperature dependence. For only two transitions, generated from benzyl alcohol, the kinetic energy released show a significant ionizing electron energy dependence. These results may reveal the role of the internal energy of reacting ions in producing the kinetic energy released some transitions produced from benzyl alcohol
Extending Newton's law from nonlocal-in-time kinetic energy
International Nuclear Information System (INIS)
Suykens, J.A.K.
2009-01-01
We study a new equation of motion derived from a context of classical Newtonian mechanics by replacing the kinetic energy with a form of nonlocal-in-time kinetic energy. It leads to a hypothetical extension of Newton's second law of motion. In a first stage the obtainable solution form is studied by considering an unknown value for the nonlocality time extent. This is done in relation to higher-order Euler-Lagrange equations and a Hamiltonian framework. In a second stage the free particle case and harmonic oscillator case are studied and compared with quantum mechanical results. For a free particle it is shown that the solution form is a superposition of the classical straight line motion and a Fourier series. We discuss the link with quanta interpretations made in Pais-Uhlenbeck oscillators. The discrete nature emerges from the continuous time setting through application of the least action principle. The harmonic oscillator case leads to energy levels that approximately correspond to the quantum harmonic oscillator levels. The solution to the extended Newton equation also admits a quantization of the nonlocality time extent, which is determined by the classical oscillator frequency. The extended equation suggests a new possible way for understanding the relationship between classical and quantum mechanics
Prediction of free turbulent mixing using a turbulent kinetic energy method
Harsha, P. T.
1973-01-01
Free turbulent mixing of two-dimensional and axisymmetric one- and two-stream flows is analyzed by a relatively simple turbulent kinetic energy method. This method incorporates a linear relationship between the turbulent shear and the turbulent kinetic energy and an algebraic relationship for the length scale appearing in the turbulent kinetic energy equation. Good results are obtained for a wide variety of flows. The technique is shown to be especially applicable to flows with heat and mass transfer, for which nonunity Prandtl and Schmidt numbers may be assumed.
The eddy kinetic energy budget in the Red Sea
Zhan, Peng; Subramanian, Aneesh C.; Yao, Fengchao; Kartadikaria, Aditya R.; Guo, Daquan; Hoteit, Ibrahim
2016-01-01
The budget of eddy kinetic energy (EKE) in the Red Sea, including the sources, redistributions and sink, is examined using a high-resolution eddy-resolving ocean circulation model. A pronounced seasonally varying EKE is identified, with its maximum
Kinetic k-essence ghost dark energy model
International Nuclear Information System (INIS)
Rozas-Fernández, Alberto
2012-01-01
A ghost dark energy model has been recently put forward to explain the current accelerated expansion of the Universe. In this model, the energy density of ghost dark energy, which comes from the Veneziano ghost of QCD, is proportional to the Hubble parameter, ρ D =αH. Here α is a constant of order Λ QCD 3 where Λ QCD ∼100 MeV is the QCD mass scale. We consider a connection between ghost dark energy with/without interaction between the components of the dark sector and the kinetic k-essence field. It is shown that the cosmological evolution of the ghost dark energy dominated Universe can be completely described a kinetic k-essence scalar field. We reconstruct the kinetic k-essence function F(X) in a flat Friedmann-Robertson-Walker Universe according to the evolution of ghost dark energy density.
Kinetic energy budget for electroconvective flows near ion selective membranes
Wang, Karen; Mani, Ali
2017-11-01
Electroconvection occurs when ions are driven from a bulk fluid through an ion-selective surface. When the driving voltage is beyond a threshold, this process undergoes a hydrodynamic instability called electroconvection, which can become chaotic due to nonlinear coupling between ion-transport, fluid flow, and electrostatic forces. Electroconvection significantly enhances ion transport and plays an important role in a wide range of electrochemical applications. We investigate this phenomenon by considering a canonical geometry consisting of a symmetric binary electrolyte between an ion-selective membrane and a reservoir using 2D direct numerical simulation (DNS). Our simulations reveal that for most practical regimes, DNS of electroconvection is expensive. Thus, a plan towards development of reduced-order models is necessary to facilitate the adoption of analysis of this phenomenon in industry. Here we use DNS to analyze the kinetic energy budget to shed light into the mechanisms sustaining flow and mixing in electroconvective flows. Our analysis reveals the relative dominance of kinetic energy sources, dissipation, and transport mechanisms sustaining electroconvection at different distances from the interface and over a wide range of input parameters. Karen Wang was supported by the National Defense Science & Engineering Graduate Fellowship (NDSEG). Ali Mani was supported by the National Science Foundation Award.
Kinetic energy budgets near the turbulent/nonturbulent interface in jets
Taveira, Rodrigo R.; da Silva, Carlos B.
2013-01-01
The dynamics of the kinetic energy near the turbulent/nonturbulent (T/NT) interface separating the turbulent from the irrotational flow regions is analysed using three direct numerical simulations of turbulent planar jets, with Reynolds numbers based on the Taylor micro-scale across the jet shear layer in the range Reλ ≈ 120-160. Important levels of kinetic energy are already present in the irrotational region near the T/NT interface. The mean pressure and kinetic energy are well described by the Bernoulli equation in this region and agree with recent results obtained from rapid distortion theory in the turbulent region [M. A. C. Teixeira and C. B. da Silva, "Turbulence dynamics near a turbulent/non-turbulent interface," J. Fluid Mech. 695, 257-287 (2012)], 10.1017/jfm.2012.17 while the normal Reynolds stresses agree with the theoretical predictions from Phillips ["The irrotational motion outside a free turbulent boundary," Proc. Cambridge Philos. Soc. 51, 220 (1955)], 10.1017/S0305004100030073. The use of conditional statistics in relation to the distance from the T/NT interface allow a detailed study of the build up of kinetic energy across the T/NT interface, pointing to a very different picture than using classical statistics. Conditional kinetic energy budgets show that apart from the viscous dissipation of kinetic energy, the maximum of all the mechanisms governing the kinetic energy are concentrated in a very narrow region distancing about one to two Taylor micro-scales from the T/NT interface. The (total and fluctuating) kinetic energy starts increasing in the irrotational region by pressure-velocity interactions - a mechanism that can act at distance, and continue to grow by advection (for the total kinetic energy) and turbulent diffusion (for the turbulent kinetic energy) inside the turbulent region. These mechanisms tend to occur preferentially around the core of the large-scale vortices existing near T/NT interface. The production of turbulent
Kinetic Storage as an Energy Management System
International Nuclear Information System (INIS)
Garcia-Tabares, L.
2007-01-01
The possibility of storing energy is increasingly important and necessary. The reason is that storage modifies the basic equation of the energy production balance which states that the power produced should equal the power consumed. When there is a storage device in the grid, this equation is modified such that, in the new balance, the energy produced should equal the algebraic sum of the energy consumed and the energy stored (positive in storage phase and negative when released). This means that the generation profile can be uncoupled from the consumption profile, with the resulting improvement of efficiency. Even small-sized storage systems can be very effective. (Author) 10 refs
Renormalizing the kinetic energy operator in elementary quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Coutinho, F A B [Faculdade de Medicina, Universidade de Sao Paulo e LIM 01-HCFMUSP, 05405-000 Sao Paulo (Brazil); Amaku, M [Faculdade de Medicina Veterinaria e Zootecnia, Universidade de Sao Paulo, 05508-970 Sao Paulo (Brazil)], E-mail: coutinho@dim.fm.usp.br
2009-09-15
In this paper, we consider solutions to the three-dimensional Schroedinger equation of the form {psi}(r) = u(r)/r, where u(0) {ne} 0. The expectation value of the kinetic energy operator for such wavefunctions diverges. We show that it is possible to introduce a potential energy with an expectation value that also diverges, exactly cancelling the kinetic energy divergence. This renormalization procedure produces a self-adjoint Hamiltonian. We solve some problems with this new Hamiltonian to illustrate its usefulness.
Renormalizing the kinetic energy operator in elementary quantum mechanics
International Nuclear Information System (INIS)
Coutinho, F A B; Amaku, M
2009-01-01
In this paper, we consider solutions to the three-dimensional Schroedinger equation of the form ψ(r) = u(r)/r, where u(0) ≠ 0. The expectation value of the kinetic energy operator for such wavefunctions diverges. We show that it is possible to introduce a potential energy with an expectation value that also diverges, exactly cancelling the kinetic energy divergence. This renormalization procedure produces a self-adjoint Hamiltonian. We solve some problems with this new Hamiltonian to illustrate its usefulness.
Renormalizing the Kinetic Energy Operator in Elementary Quantum Mechanics
Coutinho, F. A. B.; Amaku, M.
2009-01-01
In this paper, we consider solutions to the three-dimensional Schrodinger equation of the form [psi](r) = u(r)/r, where u(0) [is not equal to] 0. The expectation value of the kinetic energy operator for such wavefunctions diverges. We show that it is possible to introduce a potential energy with an expectation value that also diverges, exactly…
The kinetic energy of the vortex and pinning force in high-temperature superconductors
International Nuclear Information System (INIS)
Boiko, J.; Khar'kovskij Gosudarstvennyj Univ.; Majewski, P.; Aldinger, F.
1995-01-01
It is known that the total magnetic energy of the vortex consists of two parts: the kinetic energy, E k , which is connected with the supercurrents which circulate around the vortex, and its own magnetic energy, E mo , which is connected with the real magnetic field. Therefore, the characteristic linear spacing which corresponds to the maximum change of the kinetic energy is not related with the magnetic penetration depth, λ, but with another characteristic spacing R. Considering this fact, the idea of the nature of F p of different defects which are greater than ξ, but smaller than λ, can be modified. (orig.)
Kinetic Energy of a Trapped Fermi Gas at Finite Temperature
Grela, Jacek; Majumdar, Satya N.; Schehr, Grégory
2017-09-01
We study the statistics of the kinetic (or, equivalently, potential) energy for N noninteracting fermions in a 1 d harmonic trap of frequency ω at finite temperature T . Remarkably, we find an exact solution for the full distribution of the kinetic energy, at any temperature T and for any N , using a nontrivial mapping to an integrable Calogero-Moser-Sutherland model. As a function of temperature T and for large N , we identify (i) a quantum regime, for T ˜ℏω , where quantum fluctuations dominate and (ii) a thermal regime, for T ˜N ℏω , governed by thermal fluctuations. We show how the mean and the variance as well as the large deviation function associated with the distribution of the kinetic energy cross over from the quantum to the thermal regime as T increases.
Kinetic Boltzmann, Vlasov and Related Equations
Sinitsyn, Alexander; Vedenyapin, Victor
2011-01-01
Boltzmann and Vlasov equations played a great role in the past and still play an important role in modern natural sciences, technique and even philosophy of science. Classical Boltzmann equation derived in 1872 became a cornerstone for the molecular-kinetic theory, the second law of thermodynamics (increasing entropy) and derivation of the basic hydrodynamic equations. After modifications, the fields and numbers of its applications have increased to include diluted gas, radiation, neutral particles transportation, atmosphere optics and nuclear reactor modelling. Vlasov equation was obtained in
Reaction wheels for kinetic energy storage
Studer, P. A.
1984-11-01
In contrast to all existing reaction wheel implementations, an order of magnitude increase in speed can be obtained efficiently if power to the actuators can be recovered. This allows a combined attitude control-energy storage system to be developed with structure mounted reaction wheels. The feasibility of combining reaction wheels with energy storage wwheels is demonstrated. The power required for control torques is a function of wheel speed but this energy is not dissipated; it is stored in the wheel. The I(2)R loss resulting from a given torque is shown to be constant, independent of the design speed of the motor. What remains, in order to efficiently use high speed wheels (essential for energy storage) for control purposes, is to reduce rotational losses to acceptable levels. Progress was made in permanent magnet motor design for high speed operation. Variable field motors offer more control flexibility and efficiency over a broader speed range.
Nuclear energy related research
International Nuclear Information System (INIS)
Toerroenen, K.; Kilpi, K.
1985-01-01
This research programme plan for 1985 covers the nuclear energy related research planned to be carried out at the Technical Research Centre of Finland (VTT) and funded by the Ministry of Trade and Industry in Finland, the Nordic Council of Ministers and VTT
Nuclear energy related research
International Nuclear Information System (INIS)
Salminen, Pertti
1989-03-01
This annual Research Programme Plan covers the publicly funded nuclear energy related research planned to be carried out at the Technical Research Centre of Finland (VTT) in 1989. The research will be financed by the Ministry of Trade and Industry, the Finnish Centre for Radiation and Nuclear Safety, the Nordic Council of Ministers and VTT itself
Nuclear energy related research
International Nuclear Information System (INIS)
Salminen, P.; Mattila, L.
1990-08-01
The annual Research Programme Plan describes the publicly funded nuclear energy related research to be carried out at the Technical Research Centre of Finland (VTT) in 1990. The research is financed primarily by the Ministry of Trade and Industry (KTM), the Finnish Centre for Radiation and Nuclear Safety (STUK) and VTT itself. Utilities and industry also contribute to some projects
Nuclear energy related research
International Nuclear Information System (INIS)
Mattila, L.; Vanttola, T.
1991-10-01
The annual Research Programme Plan describes the publicly funded nuclear energy related research to be carried out mainly at the Technical Research Centre of Finland (VTT) in 1991. The research is financed primarily by the Ministry of Trade and Industry (KTM), the Finnish Centre for Radiation and Nuclear Safety (STUK) and VTT itself. Other research institutes, utilities and industry also contribute to many projects
Nuclear energy related research
International Nuclear Information System (INIS)
Rintamaa, R.
1992-05-01
The annual Research Programme Plan describes publicly funded nuclear energy related research to be carried out mainly at the Technical Research Centre of Finland (VTT) in 1992. The research is financed primarily by the Ministry of Trade and Industry (KTM), the Finnish Centre for Radiation and Nuclear Safety (STUK) and VTT itself. Other research institutes, utilities and industry also contribute to many projects
Nuclear energy related research
International Nuclear Information System (INIS)
Salminen, P.
1988-02-01
This annual Research Programme Plan covers the publicly funded nuclear energy related research planned to be carried out at the Technical Research Centre of Finland (VTT) in 1988. The research will be financed by the Ministry of Trade and Industry, the Finnish Centre for Radiation and Nuclear Safety, the Nordic Council of Ministers and VTT itself
Kinetic-energy functionals studied by surface calculations
DEFF Research Database (Denmark)
Vitos, Levente; Skriver, Hans Lomholt; Kollár, J.
1998-01-01
The self-consistent jellium model of metal surfaces is used to study the accuracy of a number of semilocal kinetic-energy functionals for independent particles. It is shown that the poor accuracy exhibited by the gradient expansion approximation and most of the semiempirical functionals in the lo...... density, high gradient limit may be subtantially improved by including locally a von Weizsacker term. Based on this, we propose a simple one-parameter Pade's approximation, which reproduces the exact Kohn-Sham surface kinetic energy over the entire range of metallic densities....
Observations of near-inertial kinetic energy inside mesoscale eddies.
Garcia Gomez, B. I.; Pallas Sanz, E.; Candela, J.
2016-02-01
The near-nertial oscillations (NIOs), generated by the wind stress on the surface mixed layer, are the inertia gravity waves with the lowest frequency and the highest kinetic energy. NIOs are important because they drive vertical mixing in the interior ocean during wave breaking events. Although the interaction between NIOs and mesoescale eddies has been reported by several authors, these studies are mostly analytical and numerical, and only few observational studies have attempted to show the differences in near-inertial kinetic energy (KEi) between anticyclonic and cyclonic eddies. In this work the spatial structure of the KEi inside the mesoscale eddies is computed using daily satellite altimetry and observations of horizontal velocity from 30 moorings equipped with acoustic Doppler current profilers in the western Gulf of Mexico. Consistent to theory, the obtained four-year KEi-composites show two times more KEi inside the anticyclonic eddies than inside the cyclonic ones. The vertical cross-sections of the KEi-composites show that the KEi is mainly located near the surface and at the edge of the cyclonic eddies (positive vorticity), whereas the KEi in anticyclonic eddies (negative vorticity) is maximum in the eddy's center and near to the base of the eddy where the NIOs become more inertial, are trapped, and amplified. A relative maximum in the upper anticyclonic eddy is also observed. The cyclonic eddies present a maximum of KEi near to the surface at 70 m, while the maximum of KEi in the anticyclonic eddies occurs between 800 and 1000 m. It is also shown the dependence between the distribution and magnitude of the KEi and the eddy's characteristics such as radius, vorticity, and amplitude.
International Nuclear Information System (INIS)
Montoya, M.; Rojas, J.; Lobato, I.
2008-01-01
The standard deviation of the final kinetic energy distribution (σ e ) as a function of mass of final fragments (m) from low energy fission of 234 U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution (σ E ) as a function of primary fragment mass (A). The second peak is attributed to a real peak on σ E (A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on σ E (A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on σ e (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the σ E (A) curve, and the observed peaks on σ e (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)
Ren, Xiu'e; Chen, Jianbiao; Li, Gang; Wang, Yanhong; Lang, Xuemei; Fan, Shuanshi
2018-08-01
The study concerned the thermal oxidative degradation kinetics of agricultural residues, peanut shell (PS) and sunflower shell (SS). The thermal behaviors were evaluated via thermogravimetric analysis and the kinetic parameters were determined by using distributed activation energy model (DAEM) and global kinetic model (GKM). Results showed that thermal oxidative decomposition of two samples processed in three zones; the ignition, burnout, and comprehensive combustibility between two agricultural residues were of great difference; and the combustion performance could be improved by boosting heating rate. The activation energy ranges calculated by the DAEM for the thermal oxidative degradation of PS and SS were 88.94-145.30 kJ mol -1 and 94.86-169.18 kJ mol -1 , respectively. The activation energy obtained by the GKM for the oxidative decomposition of hemicellulose and cellulose was obviously lower than that for the lignin oxidation at identical heating rate. To some degree, the determined kinetic parameters could acceptably simulate experimental data. Copyright © 2018 Elsevier Ltd. All rights reserved.
Local kinetic-energy density of the Airy gas
DEFF Research Database (Denmark)
Vitos, Levente; Johansson, B.; Kollár, J.
2000-01-01
The Airy gas model is used to derive an expression for the local kinetic energy in the linear potential approximation. The expression contains an explicit Laplacian term 2/5((h) over bar(2)/2m)del(mu)(2)(r) that, according to jellium surface calculations, must be a universal feature of any accura...
Crossed beam studies related to gas kinetics
International Nuclear Information System (INIS)
Buss, R.J.; Lee, Y.T.
1979-01-01
Recent advances in methods of quantum mechanical calculations, electronic computer capabilities, and microscopic experimental methods have put us in a position to understand, evaluate, and extend our current knowledge of elementary chemical reactions. It is certain that, in the future, information derived from first principles will become more important in understanding chemical processes, although chemistry will remain largely an experimental science. Microscopic experiments, such as molecular beam methods, are not the general means for obtaining precise data on rate constants. They are designed not only to reveal detailed information on reaction dynamics with which to gain a clear understanding of macroscopic phenomena, but also to provide a benchmark for the future development of quantum chemical methods for solving the problems of chemical kinetics. Actually, collection of rate constants alone is not sufficient to understand many chemical phenomena. For example, in the modeling of chemical lasers, it is necessary to have detailed information on reaction dynamics. We will discuss contributions which crossed molecular beams have made to our understanding of elementary chemical reactions. It is likely that the advancement of crossed beam methods will make it an important tool for obtaining new chemical information in the future
The influence of waves on the tidal kinetic energy resource at a tidal stream energy site
International Nuclear Information System (INIS)
Guillou, Nicolas; Chapalain, Georges; Neill, Simon P.
2016-01-01
Highlights: • We model the influence of waves on tidal kinetic energy in the Fromveur Strait. • Numerical results are compared with field data of waves and currents. • The introduction of waves improve predictions of tidal stream power during storm. • Mean spring tidal stream potential is reduced by 12% during extreme wave conditions. • Potential is reduced by 7.8% with waves forces and 5.3% with enhanced friction. - Abstract: Successful deployment of tidal energy converters relies on access to accurate and high resolution numerical assessments of available tidal stream power. However, since suitable tidal stream sites are located in relatively shallow waters of the continental shelf where tidal currents are enhanced, tidal energy converters may experience effects of wind-generated surface-gravity waves. Waves may thus influence tidal currents, and associated kinetic energy, through two non-linear processes: the interaction of wave and current bottom boundary layers, and the generation of wave-induced currents. Here, we develop a three-dimensional tidal circulation model coupled with a phase-averaged wave model to quantify the impact of the waves on the tidal kinetic energy resource of the Fromveur Strait (western Brittany) - a region that has been identified with strong potential for tidal array development. Numerical results are compared with in situ observations of wave parameters (significant wave height, peak period and mean wave direction) and current amplitude and direction 10 m above the seabed (the assumed technology hub height for this region). The introduction of waves is found to improve predictions of tidal stream power at 10 m above the seabed at the measurement site in the Strait, reducing kinetic energy by up to 9% during storm conditions. Synoptic effects of wave radiation stresses and enhanced bottom friction are more specifically identified at the scale of the Strait. Waves contribute to a slight increase in the spatial gradient of
Energy entanglement relation for quantum energy teleportation
Energy Technology Data Exchange (ETDEWEB)
Hotta, Masahiro, E-mail: hotta@tuhep.phys.tohoku.ac.j [Department of Physics, Faculty of Science, Tohoku University, Sendai 980-8578 (Japan)
2010-07-26
Protocols of quantum energy teleportation (QET), while retaining causality and local energy conservation, enable the transportation of energy from a subsystem of a many-body quantum system to a distant subsystem by local operations and classical communication through ground-state entanglement. We prove two energy-entanglement inequalities for a minimal QET model. These relations help us to gain a profound understanding of entanglement itself as a physical resource by relating entanglement to energy as an evident physical resource.
Kinetic-energy density functional: Atoms and shell structure
International Nuclear Information System (INIS)
Garcia-Gonzalez, P.; Alvarellos, J.E.; Chacon, E.
1996-01-01
We present a nonlocal kinetic-energy functional which includes an anisotropic average of the density through a symmetrization procedure. This functional allows a better description of the nonlocal effects of the electron system. The main consequence of the symmetrization is the appearance of a clear shell structure in the atomic density profiles, obtained after the minimization of the total energy. Although previous results with some of the nonlocal kinetic functionals have given incipient structures for heavy atoms, only our functional shows a clear shell structure for most of the atoms. The atomic total energies have a good agreement with the exact calculations. Discussion of the chemical potential and the first ionization potential in atoms is included. The functional is also extended to spin-polarized systems. copyright 1996 The American Physical Society
Kinetic-energy distribution for symmetric fission of 236U
International Nuclear Information System (INIS)
Brissot, R.; Bocquet, J.P.; Ristori, C.; Crancon, J.; Guet, C.R.; Nifenecker, H.A.; Montoya, M.
1980-01-01
Fission fragment kinetic-energy distributions have been measured at the Grenoble high-flux reactor with the Lohengrin facility. Spurious events were eliminated in the symmetric region by a coherence test based on a time-of-flight measurement of fragment velocities. A Monte-Carlo calculation is then performed to correct the experimental data for neutron evaporation. The difference between the most probable kinetic energy in symmetric fission and the fission in which the heavy fragment is 'magic' (Zsub(H)=50) is found to be approximately =30 MeV. The results suggest that for the symmetric case the total excitation energy available at scission is shared equally among the fragments. (author)
Kinetics with deactivation of methylcyclohexane dehydrogenation for hydrogen energy storage
Energy Technology Data Exchange (ETDEWEB)
Maria, G; Marin, A; Wyss, C; Mueller, S; Newson, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
1997-06-01
The methylcyclohexane dehydrogenation step to recycle toluene and release hydrogen is being studied as part of a hydrogen energy storage project. The reaction is performed catalytically in a fixed bed reactor, and the efficiency of this step significantly determines overall system economics. The fresh catalyst kinetics and the deactivation of the catalyst by coke play an important role in the process analysis. The main reaction kinetics were determined from isothermal experiments using a parameter sensitivity analysis for model discrimination. An activation energy for the main reaction of 220{+-}11 kJ/mol was obtained from a two-parameter model. From non-isothermal deactivation in PC-controlled integral reactors, an activation energy for deactivation of 160 kJ/mol was estimated. A model for catalyst coke content of 3-17 weight% was compared with experimental data. (author) 3 figs., 6 refs.
Split kinetic energy method for quantum systems with competing potentials
International Nuclear Information System (INIS)
Mineo, H.; Chao, Sheng D.
2012-01-01
For quantum systems with competing potentials, the conventional perturbation theory often yields an asymptotic series and the subsequent numerical outcome becomes uncertain. To tackle such a kind of problems, we develop a general solution scheme based on a new energy dissection idea. Instead of dividing the potential energy into “unperturbed” and “perturbed” terms, a partition of the kinetic energy is performed. By distributing the kinetic energy term in part into each individual potential, the Hamiltonian can be expressed as the sum of the subsystem Hamiltonians with respective competing potentials. The total wavefunction is expanded by using a linear combination of the basis sets of respective subsystem Hamiltonians. We first illustrate the solution procedure using a simple system consisting of a particle under the action of double δ-function potentials. Next, this method is applied to the prototype systems of a charged harmonic oscillator in strong magnetic field and the hydrogen molecule ion. Compared with the usual perturbation approach, this new scheme converges much faster to the exact solutions for both eigenvalues and eigenfunctions. When properly extended, this new solution scheme can be very useful for dealing with strongly coupling quantum systems. - Highlights: ► A new basis set expansion method is proposed. ► Split kinetic energy method is proposed to solve quantum eigenvalue problems. ► Significant improvement has been obtained in converging to exact results. ► Extension of such methods is promising and discussed.
Rotational and divergent kinetic energy in the mesoscale model ALADIN
Directory of Open Access Journals (Sweden)
V. Blažica
2013-03-01
Full Text Available Kinetic energy spectra from the mesoscale numerical weather prediction (NWP model ALADIN with horizontal resolution 4.4 km are split into divergent and rotational components which are then compared at horizontal scales below 300 km and various vertical levels. It is shown that about 50% of kinetic energy in the free troposphere in ALADIN is divergent energy. The percentage increases towards 70% near the surface and in the upper troposphere towards 100 hPa. The maximal percentage of divergent energy is found at stratospheric levels around 100 hPa and at scales below 100 km which are not represented by the global models. At all levels, the divergent energy spectra are characterised by shallower slopes than the rotational energy spectra, and the difference increases as horizontal scales become larger. A very similar vertical distribution of divergent energy is obtained by using the standard ALADIN approach for the computation of spectra based on the extension zone and by applying detrending approach commonly used in mesoscale NWP community.
Nonequilibrium electron energy-loss kinetics in metal clusters
Guillon, C; Fatti, N D; Vallee, F
2003-01-01
Ultrafast energy exchanges of a non-Fermi electron gas with the lattice are investigated in silver clusters with sizes ranging from 4 to 26 nm using a femtosecond pump-probe technique. The results yield evidence for a cluster-size-dependent slowing down of the short-time energy losses of the electron gas when it is strongly athermal. A constant rate is eventually reached after a few hundred femtoseconds, consistent with the electron gas internal thermalization kinetics, this behaviour reflecting evolution from an individual to a collective electron-lattice type of coupling. The timescale of this transient regime is reduced in small nanoparticles, in agreement with speeding up of the electron-electron interactions with size reduction. The experimental results are in quantitative agreement with numerical simulations of the electron kinetics.
Fragmentation and mean kinetic energy release of the nitrogen molecule
International Nuclear Information System (INIS)
Santos, A.C.F.; Melo, W.S.; Sant'Anna, M.M.; Sigaud, G.M.; Montenegro, E.C.
2007-01-01
Ionization and fragmentation of the N 2 molecule in coincidence with the final projectile charge state have been measured for the impact of 0.188-0.875 MeV/amu He + projectiles. The average kinetic energy release (KER) of the target ionic fragments is derived from the peak widths of their time-of-flight distributions. It is shown that the KER's for singly-charged products follow scaling laws irrespectively to the collision channel
Casimir rack and pinion as a miniaturized kinetic energy harvester
Miri, MirFaez; Etesami, Zahra
2016-08-01
We study a nanoscale machine composed of a rack and a pinion with no contact, but intermeshed via the lateral Casimir force. We adopt a simple model for the random velocity of the rack subject to external random forces, namely, a dichotomous noise with zero mean value. We show that the pinion, even when it experiences random thermal torque, can do work against a load. The device thus converts the kinetic energy of the random motions of the rack into useful work.
Energy Technology Data Exchange (ETDEWEB)
Vos, M. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT (Australia); Marmitt, G. G. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT (Australia); Instituto de Fisica da Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Finkelstein, Y. [Nuclear Research Center — Negev, Beer-Sheva 84190 (Israel); Moreh, R. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)
2015-09-14
Reflection electron energy loss spectra from some insulating materials (CaCO{sub 3}, Li{sub 2}CO{sub 3}, and SiO{sub 2}) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO{sub 2}, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E{sub gap}){sup 1.5}. For CaCO{sub 3}, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li{sub 2}CO{sub 3} (7.5 eV) is the first experimental estimate.
International Nuclear Information System (INIS)
Vos, M.; Marmitt, G. G.; Finkelstein, Y.; Moreh, R.
2015-01-01
Reflection electron energy loss spectra from some insulating materials (CaCO 3 , Li 2 CO 3 , and SiO 2 ) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO 2 , good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E gap ) 1.5 . For CaCO 3 , the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li 2 CO 3 (7.5 eV) is the first experimental estimate
Momentum and Kinetic Energy Before the Tackle in Rugby Union
Directory of Open Access Journals (Sweden)
Sharief Hendricks, David Karpul, Mike Lambert
2014-09-01
Full Text Available Understanding the physical demands of a tackle in match situations is important for safe and effective training, developing equipment and research. Physical components such as momentum and kinetic energy, and it relationship to tackle outcome is not known. The aim of this study was to compare momenta between ball-carrier and tackler, level of play (elite, university and junior and position (forwards vs. backs, and describe the relationship between ball-carrier and tackler mass, velocity and momentum and the tackle outcome. Also, report on the ball-carrier and tackler kinetic energy before contact and the estimated magnitude of impact (energy distributed between ball-carrier and tackler upon contact. Velocity over 0.5 seconds before contact was determined using a 2-dimensional scaled version of the field generated from a computer alogorithm. Body masses of players were obtained from their player profiles. Momentum and kinetic energy were subsequently calculated for 60 tackle events. Ball-carriers were heavier than the tacklers (ball-carrier 100 ± 14 kg vs. tackler 93 ± 11 kg, d = 0.52, p = 0.0041, n = 60. Ball-carriers as forwards had a significantly higher momentum than backs (forwards 563 ± 226 Kg.m.s-1 n = 31 vs. backs 438 ± 135 Kg.m.s-1, d = 0.63, p = 0.0012, n = 29. Tacklers dominated 57% of tackles and ball-carriers dominated 43% of tackles. Despite the ball-carrier having a mass advantage before contact more frequently than the tackler, momentum advantage and tackle dominance between the ball-carrier and tackler was proportionally similar. These findings may reflect a characteristic of the modern game of rugby where efficiently heavier players (particularly forwards are tactically predetermined to carry the ball in contact.
Directory of Open Access Journals (Sweden)
R. Sorgente
2011-08-01
to differentiate the four sub-regions as function of relative and absolute strength of the mesoscale activity. Furthermore the Baroclinic Energy Conversion term shows that in the Sardinia Channel the mesoscale activity, due to baroclinic instabilities, is significantly larger than in the other sub-regions, while a negative sign of the energy conversion, meaning a transfer of energy from the Eddy Kinetic Energy to the Eddy Available Potential Energy, has been recorded only for the surface layers of the Sicily Channel during summer.
Energy-range relations for hadrons in nuclear matter
Strugalski, Z.
1985-01-01
Range-energy relations for hadrons in nuclear matter exist similarly to the range-energy relations for charged particles in materials. When hadrons of GeV kinetic energies collide with atomic nuclei massive enough, events occur in which incident hadron is stopped completely inside the target nucleus without causing particle production - without pion production in particular. The stoppings are always accompanied by intensive emission of nucleons with kinetic energy from about 20 up to about 400 MeV. It was shown experimentally that the mean number of the emitted nucleons is a measure of the mean path in nuclear matter in nucleons on which the incident hadrons are stopped.
Momentum and Kinetic Energy Before the Tackle in Rugby Union
Hendricks, Sharief; Karpul, David; Lambert, Mike
2014-01-01
Understanding the physical demands of a tackle in match situations is important for safe and effective training, developing equipment and research. Physical components such as momentum and kinetic energy, and it relationship to tackle outcome is not known. The aim of this study was to compare momenta between ball-carrier and tackler, level of play (elite, university and junior) and position (forwards vs. backs), and describe the relationship between ball-carrier and tackler mass, velocity and momentum and the tackle outcome. Also, report on the ball-carrier and tackler kinetic energy before contact and the estimated magnitude of impact (energy distributed between ball-carrier and tackler upon contact). Velocity over 0.5 seconds before contact was determined using a 2-dimensional scaled version of the field generated from a computer alogorithm. Body masses of players were obtained from their player profiles. Momentum and kinetic energy were subsequently calculated for 60 tackle events. Ball-carriers were heavier than the tacklers (ball-carrier 100 ± 14 kg vs. tackler 93 ± 11 kg, d = 0.52, p = 0.0041, n = 60). Ball-carriers as forwards had a significantly higher momentum than backs (forwards 563 ± 226 Kg.m.s-1 n = 31 vs. backs 438 ± 135 Kg.m.s-1, d = 0.63, p = 0.0012, n = 29). Tacklers dominated 57% of tackles and ball-carriers dominated 43% of tackles. Despite the ball-carrier having a mass advantage before contact more frequently than the tackler, momentum advantage and tackle dominance between the ball-carrier and tackler was proportionally similar. These findings may reflect a characteristic of the modern game of rugby where efficiently heavier players (particularly forwards) are tactically predetermined to carry the ball in contact. Key Points First study to quantify momentum, kinetic energy, and magnitude of impact in rugby tackles across different levels in matches without a device attached to a player. Physical components alone, of either ball-carrier or
Momentum and kinetic energy before the tackle in rugby union.
Hendricks, Sharief; Karpul, David; Lambert, Mike
2014-09-01
Understanding the physical demands of a tackle in match situations is important for safe and effective training, developing equipment and research. Physical components such as momentum and kinetic energy, and it relationship to tackle outcome is not known. The aim of this study was to compare momenta between ball-carrier and tackler, level of play (elite, university and junior) and position (forwards vs. backs), and describe the relationship between ball-carrier and tackler mass, velocity and momentum and the tackle outcome. Also, report on the ball-carrier and tackler kinetic energy before contact and the estimated magnitude of impact (energy distributed between ball-carrier and tackler upon contact). Velocity over 0.5 seconds before contact was determined using a 2-dimensional scaled version of the field generated from a computer alogorithm. Body masses of players were obtained from their player profiles. Momentum and kinetic energy were subsequently calculated for 60 tackle events. Ball-carriers were heavier than the tacklers (ball-carrier 100 ± 14 kg vs. tackler 93 ± 11 kg, d = 0.52, p = 0.0041, n = 60). Ball-carriers as forwards had a significantly higher momentum than backs (forwards 563 ± 226 Kg(.)m(.)s(-1) n = 31 vs. backs 438 ± 135 Kg(.)m(.)s(-1), d = 0.63, p = 0.0012, n = 29). Tacklers dominated 57% of tackles and ball-carriers dominated 43% of tackles. Despite the ball-carrier having a mass advantage before contact more frequently than the tackler, momentum advantage and tackle dominance between the ball-carrier and tackler was proportionally similar. These findings may reflect a characteristic of the modern game of rugby where efficiently heavier players (particularly forwards) are tactically predetermined to carry the ball in contact. Key PointsFirst study to quantify momentum, kinetic energy, and magnitude of impact in rugby tackles across different levels in matches without a device attached to a player.Physical components alone, of either ball
Discrete kinetic models from funneled energy landscape simulations.
Directory of Open Access Journals (Sweden)
Nicholas P Schafer
Full Text Available A general method for facilitating the interpretation of computer simulations of protein folding with minimally frustrated energy landscapes is detailed and applied to a designed ankyrin repeat protein (4ANK. In the method, groups of residues are assigned to foldons and these foldons are used to map the conformational space of the protein onto a set of discrete macrobasins. The free energies of the individual macrobasins are then calculated, informing practical kinetic analysis. Two simple assumptions about the universality of the rate for downhill transitions between macrobasins and the natural local connectivity between macrobasins lead to a scheme for predicting overall folding and unfolding rates, generating chevron plots under varying thermodynamic conditions, and inferring dominant kinetic folding pathways. To illustrate the approach, free energies of macrobasins were calculated from biased simulations of a non-additive structure-based model using two structurally motivated foldon definitions at the full and half ankyrin repeat resolutions. The calculated chevrons have features consistent with those measured in stopped flow chemical denaturation experiments. The dominant inferred folding pathway has an "inside-out", nucleation-propagation like character.
Energy Technology Data Exchange (ETDEWEB)
Montoya, M.; Rojas, J. [Instituto Peruano de Energia Nuclear, Av. Canada 1470, Lima 41 (Peru); Lobato, I. [Facultad de Ciencias, Universidad Nacional de Ingenieria, Av. Tupac Amaru 210, Apartado Postal 31-139, Lima (Peru)]. e-mail: mmontoya@ipen.gob.pe
2008-07-01
The standard deviation of the final kinetic energy distribution ({sigma}{sub e}) as a function of mass of final fragments (m) from low energy fission of {sup 234}U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution ({sigma}{sub E}) as a function of primary fragment mass (A). The second peak is attributed to a real peak on {sigma}{sub E}(A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on {sigma}{sub E}(A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on {sigma}{sub e} (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the {sigma}{sub E} (A) curve, and the observed peaks on {sigma}{sub e} (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)
Skamarock, W. C.
2017-12-01
We have performed week-long full-physics simulations with the MPAS global model at 15 km cell spacing using vertical mesh spacings of 800, 400, 200 and 100 meters in the mid-troposphere through the mid-stratosphere. We find that the horizontal kinetic energy spectra in the upper troposphere and stratosphere does not converge with increasing vertical resolution until we reach 200 meter level spacing. Examination of the solutions indicates that significant inertia-gravity waves are not vertically resolved at the lower vertical resolutions. Diagnostics from the simulations indicate that the primary kinetic energy dissipation results from the vertical mixing within the PBL parameterization and from the gravity-wave drag parameterization, with smaller but significant contributions from damping in the vertical transport scheme and from the horizontal filters in the dynamical core. Most of the kinetic energy dissipation in the free atmosphere occurs within breaking mid-latitude baroclinic waves. We will briefly review these results and their implications for atmospheric model configuration and for atmospheric dynamics, specifically that related to the dynamics associated with the mesoscale kinetic energy spectrum.
Balance of liquid-phase turbulence kinetic energy equation for bubble-train flow
International Nuclear Information System (INIS)
Ilic, Milica; Woerner, Martin; Cacuci, Dan Gabriel
2004-01-01
In this paper the investigation of bubble-induced turbulence using direct numerical simulation (DNS) of bubbly two-phase flow is reported. DNS computations are performed for a bubble-driven liquid motion induced by a regular train of ellipsoidal bubbles rising through an initially stagnant liquid within a plane vertical channel. DNS data are used to evaluate balance terms in the balance equation for the liquid phase turbulence kinetic energy. The evaluation comprises single-phase-like terms (diffusion, dissipation and production) as well as the interfacial term. Special emphasis is placed on the procedure for evaluation of interfacial quantities. Quantitative analysis of the balance equation for the liquid phase turbulence kinetic energy shows the importance of the interfacial term which is the only source term. The DNS results are further used to validate closure assumptions employed in modelling of the liquid phase turbulence kinetic energy transport in gas-liquid bubbly flows. In this context, the performance of respective closure relations in the transport equation for liquid turbulence kinetic energy within the two-phase k-ε and the two-phase k-l model is evaluated. (author)
Flywheels for Low-Speed Kinetic Energy Storage Systems
Energy Technology Data Exchange (ETDEWEB)
Portnov, G.; Cruz, I.; Arias, F.; Fiffe, R. P.
2003-07-01
A brief overview of different steel disc-type flywheels is presented. It contents the analysis of relationship between stress-state and kinetic energy of rotating body, comparison of the main characteristics of flywheels and description of their optimization procedures. It is shown that profiles of the discs calculated on a basis of plane stress-state assumption may be considered only as a starting point for its further improvement using 3-D approach. The aim of the review is to provide a designer for a insight into problem of shaping of steel flywheels. (Author) 19 refs.
Tunneling and reflection in unimolecular reaction kinetic energy release distributions
Hansen, K.
2018-02-01
The kinetic energy release distributions in unimolecular reactions is calculated with detailed balance theory, taking into account the tunneling and the reflection coefficient in three different types of transition states; (i) a saddle point corresponding to a standard RRKM-type theory, (ii) an attachment Langevin cross section, and (iii) an absorbing sphere potential at short range, without long range interactions. Corrections are significant in the one dimensional saddle point states. Very light and lightly bound absorbing systems will show measurable effects in decays from the absorbing sphere, whereas the Langevin cross section is essentially unchanged.
About total kinetic energy distribution between fragments of binary fission
International Nuclear Information System (INIS)
Khugaev, A.V.; Koblik, Yu.N.; Pikul, V.P.; Ioannou, P.; Dimovasili, E.
2002-01-01
At the investigation of binary fission reactions one of the main characteristic of process is total kinetic energy (TKE) of fission fragments and it distribution between them. From the values of these characteristics it is possible to extract the information about structure of fission fragments in the break up point of initial fissionable nuclear system. In our work TKE dependence from the deformation parameters of shape and density distribution of charge in the fission fragments are investigated. In the end of paper some generalizations of obtaining results are carried out and presented in the form of tables and figures
Functional derivative of noninteracting kinetic energy density functional
International Nuclear Information System (INIS)
Liu Shubin; Ayers, Paul W.
2004-01-01
Proofs from different theoretical frameworks, namely, the Hohenbergh-Kohn theorems, the Kohn-Sham scheme, and the first-order density matrix representation, have been presented in this paper to show that the functional derivative of the noninteracting kinetic energy density functional can uniquely be expressed as the negative of the Kohn-Sham effective potential, arbitrary only to an additive orbital-independent constant. Key points leading to the current result as well as confusion about the quantity in the literature are briefly discussed
Flywheels for Low-Speed Kinetic Energy Storage Systems
International Nuclear Information System (INIS)
Portnov, G.; Cruz, I.; Arias, F.; Fiffe, R. P.
2003-01-01
A brief overview of different steel disc-type flywheels is presented. It contents the analysis of relationship between stress-state and kinetic energy of rotating body, comparison of the main characteristics of flywheels and description of their optimization procedures. It is shown that pro files of the discs calculated on a basis of plane stress-state assumption may be considered only as a starting point for its further improvement using 3-D approach. The aim of the review is to provide a designer for a insight into problem of shaping of steel flywheels. (Author) 19 refs
Trivial constraints on orbital-free kinetic energy density functionals
Luo, Kai; Trickey, S. B.
2018-03-01
Approximate kinetic energy density functionals (KEDFs) are central to orbital-free density functional theory. Limitations on the spatial derivative dependencies of KEDFs have been claimed from differential virial theorems. We identify a central defect in the argument: the relationships are not true for an arbitrary density but hold only for the minimizing density and corresponding chemical potential. Contrary to the claims therefore, the relationships are not constraints and provide no independent information about the spatial derivative dependencies of approximate KEDFs. A simple argument also shows that validity for arbitrary v-representable densities is not restored by appeal to the density-potential bijection.
Uptake kinetics of relatively insoluble particles by tracheobronchial lymph nodes
International Nuclear Information System (INIS)
Thomas, R.G.
1976-01-01
Tracheobronchial lymph nodes accumulate a portion of material deposited in the deep lung following inhalation of relatively insoluble particles. Experiments involving a variety of compounds, inhaled singly or repeatedly, indicate that the kinetics of lymph node uptake are fairly independent of particle characteristics and mammalian species. The buildup per unit weight of nodal tissue compared with that of lung tissue, with time, can be represented by a linear logarithmic function. However, since the scatter in experimental points may be large at any given time after inhalation exposure, a number of different kinetic descriptions of uptake can be derived. The logarithmic pattern of accumulation can be approximated over an extended time range (several years) by use of a combination of first-order kinetics of loss from the lung and of buildup in lymph nodes, but it is recognized that the processes are much more complicated than this treatment would indicate. Clearance (loss) from the lymph nodes is not well defined, but this aspect is discussed in light of the kinetic models presented
Work fluctuation theorems and free energy from kinetic theory
Brey, J. Javier; Ruiz-Montero, M. J.; Domínguez, Álvaro
2018-01-01
The formulation of the first and second principles of thermodynamics for a particle in contact with a heat bath and submitted to an external force is analyzed, by means of the Boltzmann-Lorentz kinetic equation. The possible definitions of the thermodynamic quantities are discussed in the light of the H theorem verified by the distribution of the particle. The work fluctuation relations formulated by Bochkov and Kuzovlev, and by Jarzynski, respectively, are derived from the kinetic equation. In addition, particle simulations using both the direct simulation Monte Carlo method and molecular dynamics, are used to investigate the practical accuracy of the results. Work distributions are also measured, and they turn out to be rather complex. On the other hand, they seem to depend very little, if any, on the interaction potential between the intruder and the bath.
Recommended Auger-electron kinetic energies for 42 elemental solids
International Nuclear Information System (INIS)
Powell, C.J.
2010-01-01
An analysis is presented of Auger-electron kinetic energies (KEs) from four data sources for 65 Auger transitions in 45 elemental solids. For each data source, a single instrument had been used to measure KEs for many elements. In order to compare KEs from two sources, it was necessary to recalibrate the energy scales of each instrument using recommended reference data. Mean KEs are given for most of the Auger transitions for which there were at least two independent measurements and for which differences from the mean KEs were considered acceptably small. In several cases, comparisons were made to published KE data to resolve discrepancies. We are able to recommend mean KEs for 59 Auger transitions from 42 elemental solids and to provide estimates of the uncertainties of these KEs. This compilation should be useful for the determination of chemical shifts of Auger peaks in Auger electron spectroscopy and X-ray photoelectron spectroscopy.
Borén, Jan; Watts, Gerald F; Adiels, Martin; Söderlund, Sanni; Chan, Dick C; Hakkarainen, Antti; Lundbom, Nina; Matikainen, Niina; Kahri, Juhani; Vergès, Bruno; Barrett, P Hugh R; Taskinen, Marja-Riitta
2015-10-01
Patients with obesity and diabetes mellitus have increased risk of cardiovascular disease. A major cause is an atherogenic dyslipidemia related primarily to elevated plasma concentrations of triglyceride-rich lipoproteins. The aim of this study was to clarify determinants of plasma triglyceride concentration. We focused on factors that predict the kinetics of very-low density lipoprotein 1 (VLDL1) triglycerides. A multicenter study using dual stable isotopes (deuterated leucine and glycerol) and multicompartmental modeling was performed to elucidate the kinetics of triglycerides and apoB in VLDL1 in 46 subjects with abdominal obesity and additional cardiometabolic risk factors. Results showed that plasma triglyceride concentrations were dependent on both the secretion rate (r=0.44, Ptriglycerides and VLDL1-apoB. Liver fat mass was independently and directly associated with secretion rates of VLDL1-triglycerides (r=0.56, Ptriglycerides (r=0.48, Ptriglyceride concentrations in abdominal obesity are determined by the kinetics of VLDL1 subspecies, catabolism being mainly dependent on apoC-III concentration and secretion on liver fat content. Reduction in liver fat and targeting apoC-III may be an effective approach for correcting triglyceride metabolism atherogenic dyslipidemia in obesity. © 2015 American Heart Association, Inc.
Jackson, A. T.
1973-01-01
Reviews theoretical and experimental fundamentals of Einstein's theory of general relativity. Indicates that recent development of the theory of the continually expanding universe may lead to revision of the space-time continuum of the finite and unbounded universe. (CC)
Kinetic Energy of Tornadoes in the United States.
Fricker, Tyler; Elsner, James B
2015-01-01
Tornadoes can cause catastrophic destruction. Here total kinetic energy (TKE) as a metric of destruction is computed from the fraction of the tornado path experiencing various damage levels and a characteristic wind speed for each level. The fraction of the path is obtained from a model developed for the Nuclear Regulatory Commission that combines theory with empirical data. TKE is validated as a useful metric by comparing it to other indexes and loss indicators. Half of all tornadoes have TKE exceeding 62.1 GJ and a quarter have TKE exceeding 383.2 GJ. One percent of the tornadoes have TKE exceeding 31.9 TJ. April has more energy than May with fewer tornadoes; March has more energy than June with half as many tornadoes. September has the least energy but November and December have the fewest tornadoes. Alabama ranks number one in terms of tornado energy with 2.48 PJ over the period 2007-2013. TKE can be used to help better understand the changing nature of tornado activity.
Kinetic Energy of Tornadoes in the United States.
Directory of Open Access Journals (Sweden)
Tyler Fricker
Full Text Available Tornadoes can cause catastrophic destruction. Here total kinetic energy (TKE as a metric of destruction is computed from the fraction of the tornado path experiencing various damage levels and a characteristic wind speed for each level. The fraction of the path is obtained from a model developed for the Nuclear Regulatory Commission that combines theory with empirical data. TKE is validated as a useful metric by comparing it to other indexes and loss indicators. Half of all tornadoes have TKE exceeding 62.1 GJ and a quarter have TKE exceeding 383.2 GJ. One percent of the tornadoes have TKE exceeding 31.9 TJ. April has more energy than May with fewer tornadoes; March has more energy than June with half as many tornadoes. September has the least energy but November and December have the fewest tornadoes. Alabama ranks number one in terms of tornado energy with 2.48 PJ over the period 2007-2013. TKE can be used to help better understand the changing nature of tornado activity.
Pyrolysis characteristics and kinetics of low rank coals by distributed activation energy model
International Nuclear Information System (INIS)
Song, Huijuan; Liu, Guangrui; Wu, Jinhu
2016-01-01
Highlights: • Types of carbon in coal structure were investigated by curve-fitted "1"3C NMR spectra. • The work related pyrolysis characteristics and kinetics with coal structure. • Pyrolysis kinetics of low rank coals were studied by DAEM with Miura integral method. • DAEM could supply accurate extrapolations under relatively higher heating rates. - Abstract: The work was conducted to investigate pyrolysis characteristics and kinetics of low rank coals relating with coal structure by thermogravimetric analysis (TGA), the distributed activation energy model (DAEM) and solid-state "1"3C Nuclear Magnetic Resonance (NMR). Four low rank coals selected from different mines in China were studied in the paper. TGA was carried out with a non-isothermal temperature program in N_2 at the heating rate of 5, 10, 20 and 30 °C/min to estimate pyrolysis processes of coal samples. The results showed that corresponding characteristic temperatures and the maximum mass loss rates increased as heating rate increased. Pyrolysis kinetics parameters were investigated by the DAEM using Miura integral method. The DAEM was accurate verified by the good fit between the experimental and calculated curves of conversion degree x at the selected heating rates and relatively higher heating rates. The average activation energy was 331 kJ/mol (coal NM), 298 kJ/mol (coal NX), 302 kJ/mol (coal HLJ) and 196 kJ/mol (coal SD), respectively. The curve-fitting analysis of "1"3C NMR spectra was performed to characterize chemical structures of low rank coals. The results showed that various types of carbon functional groups with different relative contents existed in coal structure. The work indicated that pyrolysis characteristics and kinetics of low rank coals were closely associated with their chemical structures.
Nuclear energy related research
International Nuclear Information System (INIS)
Salminen, Pertti
1987-02-01
This annual Research Programme Plan covers the nuclear related research planned to be carried out at the Technical Research Centre of Finland (VTT) in 1987 and funded by the Ministry of Trade and Industry in Finland, the Nordic Council of Ministers and VTT itself
ENERGY DISSIPATION IN MAGNETIC NULL POINTS AT KINETIC SCALES
International Nuclear Information System (INIS)
Olshevsky, Vyacheslav; Lapenta, Giovanni; Divin, Andrey; Eriksson, Elin; Markidis, Stefano
2015-01-01
We use kinetic particle-in-cell and MHD simulations supported by an observational data set to investigate magnetic reconnection in clusters of null points in space plasma. The magnetic configuration under investigation is driven by fast adiabatic flux rope compression that dissipates almost half of the initial magnetic field energy. In this phase powerful currents are excited producing secondary instabilities, and the system is brought into a state of “intermittent turbulence” within a few ion gyro-periods. Reconnection events are distributed all over the simulation domain and energy dissipation is rather volume-filling. Numerous spiral null points interconnected via their spines form null lines embedded into magnetic flux ropes; null point pairs demonstrate the signatures of torsional spine reconnection. However, energy dissipation mainly happens in the shear layers formed by adjacent flux ropes with oppositely directed currents. In these regions radial null pairs are spontaneously emerging and vanishing, associated with electron streams and small-scale current sheets. The number of spiral nulls in the simulation outweighs the number of radial nulls by a factor of 5–10, in accordance with Cluster observations in the Earth's magnetosheath. Twisted magnetic fields with embedded spiral null points might indicate the regions of major energy dissipation for future space missions such as the Magnetospheric Multiscale Mission
Kinetic energy of throughfall in a highly diverse forest ecosystem in the humid subtropics
Geißler, Christian; Kühn, Peter; Scholten, Thomas
2010-05-01
After decades of research it is generally accepted that vegetation is a key factor in controlling soil erosion. Therefore, in ecosystems where erosion is a serious problem, afforestation is a common measure against erosion. Most of the studies in the last decades focused on agricultural systems and less attention was paid to natural systems. To understand the mechanisms preventing soil erosion in natural systems the processes have to be studied in detail and gradually. The first step and central research question is on how the canopies of the tree layer alter the properties of rainfall and generate throughfall. Kinetic energy is a widely used parameter to estimate the erosion potential of open field rainfall and throughfall. In the past, numerous studies have shown that vegetation of a certain height enhances the kinetic energy under the canopy (Chapman 1948, Mosley 1982, Vis 1986, Hall & Calder 1993, Nanko et al. 2006, Nanko et al. 2008) in relation to open field rainfall. This is mainly due to a shift in the drop size distribution to less but larger drops possessing a higher amount of kinetic energy. In vital forest ecosystems lower vegetation (shrubs, herbs) as well as a continuous litter layer protects the forest soil from the impact of large drops. The influence of biodiversity, specific forest stands or single species in this process system is still in discussion. In the present study calibrated splash cups (after Ellison 1947, Geißler et al. under review) have been used to detect differences in kinetic energy on the scale of specific species and on the scale of forest stands of contrasting age and biodiversity in a natural forest ecosystem. The splash cups have been calibrated experimentally using a laser disdrometer. The results show that the kinetic energy of throughfall produced by the tree layer increases with the age of the specific forest stand. The average throughfall kinetic energy (J m-2) is about 2.6 times higher in forests than under open field
Utilization of rotor kinetic energy storage for hybrid vehicles
Hsu, John S [Oak Ridge, TN
2011-05-03
A power system for a motor vehicle having an internal combustion engine, the power system comprises an electric machine (12) further comprising a first excitation source (47), a permanent magnet rotor (28) and a magnetic coupling rotor (26) spaced from the permanent magnet rotor and at least one second excitation source (43), the magnetic coupling rotor (26) also including a flywheel having an inertial mass to store kinetic energy during an initial acceleration to an operating speed; and wherein the first excitation source is electrically connected to the second excitation source for power cycling such that the flywheel rotor (26) exerts torque on the permanent magnet rotor (28) to assist braking and acceleration of the permanent magnet rotor (28) and consequently, the vehicle. An axial gap machine and a radial gap machine are disclosed and methods of the invention are also disclosed.
Mass independent kinetic energy reducing inlet system for vacuum environment
Reilly, Peter T. A. [Knoxville, TN
2010-12-14
A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.
Comment on 'Kinetic energy as a density functional'
International Nuclear Information System (INIS)
Holas, A.; March, N.H.
2002-01-01
In a recent paper, Nesbet [Phys. Rev. A 65, 010502(R) (2001)] has proposed dropping ''the widespread but unjustified assumption that the existence of a ground-state density functional for the kinetic energy, T s [ρ], of an N-electron system implies the existence of a density-functional derivative, δT s [ρ]/δρ(r), equivalent to a local potential function,'' because, according to his arguments, this derivative 'has the mathematical character of a linear operator that acts on orbital wave functions'. Our Comment demonstrates that the statement called by Nesbet an 'unjustified assumption' happens, in fact, to be a rigorously proven theorem. Therefore, his previous conclusions stemming from his different view of this derivative, which undermined the foundations of density-functional theory, can be discounted
Kinetic energy distributions of ions after surface collisions
International Nuclear Information System (INIS)
Short, R.T.; Todd, P.J.; Grimm, C.C.
1991-01-01
As a part of the development of an organic ion microprobe, to be used for imaging of particular organic compounds in biological tissue, various methods of quadrupole-based tandem mass spectroscopy (MS/MS) have been investigated. High transmission efficiency is essential for the success of the organic ion microprobe, due to expected low analyte concentrations in biological tissue and the potential for sample damage from prolonged exposure to the primary ion beam. MS/MS is necessary for organic ion imaging because of the complex nature of the biological matrices. The goal of these studies of was to optimize the efficiency of daughter ion production and transmission by first determining daughter ion properties and then designing ion optics based on those properties. The properties of main interest are daughter ion kinetic energy and angular distribution. 1 fig
Energy scavenging strain absorber: application to kinetic dielectric elastomer generator
Jean-Mistral, C.; Beaune, M.; Vu-Cong, T.; Sylvestre, A.
2014-03-01
Dielectric elastomer generators (DEGs) are light, compliant, silent energy scavengers. They can easily be incorporated into clothing where they could scavenge energy from the human kinetic movements for biomedical applications. Nevertheless, scavengers based on dielectric elastomers are soft electrostatic generators requiring a high voltage source to polarize them and high external strain, which constitutes the two major disadvantages of these transducers. We propose here a complete structure made up of a strain absorber, a DEG and a simple electronic power circuit. This new structure looks like a patch, can be attached on human's wear and located on the chest, knee, elbow… Our original strain absorber, inspired from a sailing boat winch, is able to heighten the external available strain with a minimal factor of 2. The DEG is made of silicone Danfoss Polypower and it has a total area of 6cm per 2.5cm sustaining a maximal strain of 50% at 1Hz. A complete electromechanical analytical model was developed for the DEG associated to this strain absorber. With a poling voltage of 800V, a scavenged energy of 0.57mJ per cycle is achieved with our complete structure. The performance of the DEG can further be improved by enhancing the imposed strain, by designing a stack structure, by using a dielectric elastomer with high dielectric permittivity.
Symmetry Relations in Chemical Kinetics Arising from Microscopic Reversibility
Adib, Artur B.
2006-01-01
It is shown that the kinetics of time-reversible chemical reactions having the same equilibrium constant but different initial conditions are closely related to one another by a directly measurable symmetry relation analogous to chemical detailed balance. In contrast to detailed balance, however, this relation does not require knowledge of the elementary steps that underlie the reaction, and remains valid in regimes where the concept of rate constants is ill defined, such as at very short times and in the presence of low activation barriers. Numerical simulations of a model of isomerization in solution are provided to illustrate the symmetry under such conditions, and potential applications in protein folding or unfolding are pointed out.
Relative ultrasound energy measurement circuit
Gustafsson, E.Martin I.; Johansson, Jonny; Delsing, Jerker
2005-01-01
A relative ultrasound energy estimation circuit has been designed in a standard 0.35-μm CMOS process, to be a part of a thumb size internet connected wireless ultrasound measurement system. This circuit measures the relative energy between received ultrasound pulses, and presents an output signal that is linear to the received energy. Post-layout simulations indicate 7 bit linearity for 500 mV input signals, 5 μsec startup and stop times, 2.6 mW power consumption during active state. The acti...
Revisiting the density scaling of the non-interacting kinetic energy.
Borgoo, Alex; Teale, Andrew M; Tozer, David J
2014-07-28
Scaling relations play an important role in the understanding and development of approximate functionals in density functional theory. Recently, a number of these relationships have been redefined in terms of the Kohn-Sham orbitals [Calderín, Phys. Rev. A: At., Mol., Opt. Phys., 2013, 86, 032510]. For density scaling the author proposed a procedure involving a multiplicative scaling of the Kohn-Sham orbitals whilst keeping their occupation numbers fixed. In the present work, the differences between this scaling with fixed occupation numbers and that of previous studies, where the particle number change implied by the scaling was accommodated through the use of the grand canonical ensemble, are examined. We introduce the terms orbital and ensemble density scaling for these approaches, respectively. The natural ambiguity of the density scaling of the non-interacting kinetic energy functional is examined and the ancillary definitions implicit in each approach are highlighted and compared. As a consequence of these differences, Calderín recovered a homogeneity of degree 1 for the non-interacting kinetic energy functional under orbital scaling, contrasting recent work by the present authors [J. Chem. Phys., 2012, 136, 034101] where the functional was found to be inhomogeneous under ensemble density scaling. Furthermore, we show that the orbital scaling result follows directly from the linearity and the single-particle nature of the kinetic energy operator. The inhomogeneity of the non-interacting kinetic energy functional under ensemble density scaling can be quantified by defining an effective homogeneity. This quantity is shown to recover the homogeneity values for important approximate forms that are exact for limiting cases such as the uniform electron gas and one-electron systems. We argue that the ensemble density scaling provides more insight into the development of new functional forms.
Seldam, C.A. ten; Groot, S.R. de
1952-01-01
From Jensen's and Gombás' modification of the statistical Thomas-Fermi atom model, a theory for compressed atoms is developed by changing the boundary conditions. Internal kinetic energy and polarizability of argon are calculated as functions of pressure. At 1000 atm. an internal kinetic energy of
Bulyzhenkov, I. E.
2018-02-01
Translational ordering of the internal kinematic chaos provides the Special Relativity referents for the geodesic motion of warm thermodynamical bodies. Taking identical mathematics, relativistic physics of the low speed transport of time-varying heat-energies differs from Newton's physics of steady masses without internal degrees of freedom. General Relativity predicts geodesic changes of the internal heat-energy variable under the free gravitational fall and the geodesic turn in the radial field center. Internal heat variations enable cyclic dynamics of decelerated falls and accelerated takeoffs of inertial matter and its structural self-organization. The coordinate speed of the ordered spatial motion takes maximum under the equipartition of relativistic internal and translational kinetic energies. Observable predictions are discussed for verification/falsification of the principle of equipartition as a new basic for the ordered motion and self-organization in external fields, including gravitational, electromagnetic, and thermal ones.
Numeric kinetic energy operators for molecules in polyspherical coordinates
International Nuclear Information System (INIS)
Sadri, Keyvan; Meyer, Hans-Dieter; Lauvergnat, David; Gatti, Fabien
2012-01-01
Generalized curvilinear coordinates, as, e.g., polyspherical coordinates, are in general better adapted to the resolution of the nuclear Schrödinger equation than rectilinear ones like the normal mode coordinates. However, analytical expressions of the kinetic energy operators (KEOs) for molecular systems in polyspherical coordinates may be prohibitively complicated for large systems. In this paper we propose a method to generate a KEO numerically and bring it to a form practicable for dynamical calculations. To examine the new method we calculated vibrational spectra and eigenenergies for nitrous acid (HONO) and compare it with results obtained with an exact analytical KEO derived previously [F. Richter, P. Rosmus, F. Gatti, and H.-D. Meyer, J. Chem. Phys. 120, 6072 (2004)]. In a second example we calculated π→π* photoabsorption spectrum and eigenenergies of ethene (C 2 H 4 ) and compared it with previous work [M. R. Brill, F. Gatti, D. Lauvergnat, and H.-D. Meyer, Chem. Phys. 338, 186 (2007)]. In this ethene study the dimensionality was reduced from 12 to 6 by freezing six internal coordinates. Results for both molecules show that the proposed method for obtaining an approximate KEO is reliable for dynamical calculations. The error in eigenenergies was found to be below 1 cm −1 for most states calculated.
Kinetic Energy Dissipation on Labyrinth Configuration Stepped Spillway
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Jaafar S. Maatooq
2017-12-01
Full Text Available In present work a labyrinth (zigzag, in shape has been used to configure the steps of stepped spillway by using the physical model. This configuration does not introduce previously by investigators or in construction techniques of dams or cascades. It would be expected to improve the flow over chute. A magnifying the width path of each step to become, LT, instead of, W, will induce the interlocking between the mainstream and that spread laterally due to labyrinth path. This phenomenon leads to reduce the jet velocities near the surfaces, thus minimizing the ability of cavitation and with increasing a circulation regions the ability of air entrainment be maximized. The results were encouraging, (e.g., the reverse performance has recorded for spillway slope. From the evaluation of outcome, the average recorded of percentage profits of kinetic energy dissipation with a labyrinth shape compared with the results of traditional shape were ranged between (13- 44%. Different predictive formulas have been proposed based on iteration analysis, can be recommended for evaluation and design.
Chemical bond as a test of density-gradient expansions for kinetic and exchange energies
International Nuclear Information System (INIS)
Perdew, J.P.; Levy, M.; Painter, G.S.; Wei, S.; Lagowski, J.B.
1988-01-01
Errors in kinetic and exchange contributions to the molecular bonding energy are assessed for approximate density functionals by reference to near-exact Hartree-Fock values. From the molecular calculations of Allan et al. and of Lee and Ghosh, it is demonstrated that the density-gradient expansion does not accurately describe the noninteracting kinetic contribution to the bonding energy, even when this expansion is carried to fourth order and applied in its spin-density-functional form to accurate Hartree-Fock densities. In a related study, it is demonstrated that the overbinding of molecules such as N 2 and F 2 , which occurs in the local-spin-density (LSD) approximation for the exchange-correlation energy, is not attributable to errors in the self-consistent LSD densities. Contrary to expectations based upon the Gunnarsson-Jones nodality argument, it is found that the LSD approximation for the exchange energy can seriously overbind a molecule even when bonding does not create additional nodes in the occupied valence orbitals. LSD and exact values for the exchange contribution to the bonding energy are displayed and discussed for several molecules
Dai, A. J.; Chen, Z. Y.; Huang, D. W.; Tong, R. H.; Zhang, J.; Wei, Y. N.; Ma, T. K.; Wang, X. L.; Yang, H. Y.; Gao, H. L.; Pan, Y.; the J-TEXT Team
2018-05-01
A large number of runaway electrons (REs) with energies as high as several tens of mega-electron volt (MeV) may be generated during disruptions on a large-scale tokamak. The kinetic energy carried by REs is eventually deposited on the plasma-facing components, causing damage and posing a threat on the operation of the tokamak. The remaining magnetic energy following a thermal quench is significant on a large-scale tokamak. The conversion of magnetic energy to runaway kinetic energy will increase the threat of runaway electrons on the first wall. The magnetic energy dissipated inside the vacuum vessel (VV) equals the decrease of initial magnetic energy inside the VV plus the magnetic energy flowing into the VV during a disruption. Based on the estimated magnetic energy, the evolution of magnetic-kinetic energy conversion are analyzed through three periods in disruptions with a runaway current plateau.
Kinetic energy management in road traffic injury prevention: a call for action
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Davoud Khorasani-Zavareh
2015-01-01
Full Text Available Abstract: By virtue of their variability, mass and speed have important roles in transferring energies during a crash incidence (kinetic energy. The sum of kinetic energy is important in determining an injury severity and that is equal to one half of the vehicle mass multiplied by the square of the vehicle speed. To meet the Vision Zero policy (a traffic safety policy prevention activities should be focused on vehicle speed management. Understanding the role of kinetic energy will help to develop measures to reduce the generation, distribution, and effects of this energy during a road traffic crash. Road traffic injury preventive activities necessitate Kinetic energy management to improve road user safety.
Origins of Eddy Kinetic Energy in the Bay of Bengal
Chen, Gengxin; Li, Yuanlong; Xie, Qiang; Wang, Dongxiao
2018-03-01
By analyzing satellite observational data and ocean general circulation model experiments, this study investigates the key processes that determine the spatial distribution and seasonality of intraseasonal eddy kinetic energy (EKE) within the Bay of Bengal (BOB). It is revealed that a complicated mechanism involving both local and remote wind forcing and ocean internal instability is responsible for the generation and modulation of EKE in this region. High-level EKE mainly resides in four regions: east of Sri Lanka (Region 1), the western BOB (Region 2), northwest of Sumatra (Region 3), and the coastal rim of the BOB (Region 4). The high EKE levels in Regions 1 and 2 are predominantly produced by ocean internal instability, which contributes 90% and 79%, respectively. Prominent seasonality is also observed in these two regions, with higher EKE levels in boreal spring and fall due to enhanced instability of the East Indian Coast Current and the Southwest Monsoon Current, respectively. In contrast, ocean internal instability contributes 49% and 52% of the total EKE in Regions 3 and 4, respectively, whereas the atmospheric forcing of intraseasonal oscillations (ISOs) also plays an important role. ISOs produce EKE mainly through wind stress, involving both the remote effect of equatorial winds and the local effect of monsoonal winds. Equatorial-origin wave signals significantly enhance the EKE levels in Regions 3 and 4, in the form of reflected Rossby waves and coastal Kelvin waves, respectively. The local wind forcing effect through Ekman pumping also has a significant contribution in Regions 3 and 4 (24% and 22%, respectively).
International Nuclear Information System (INIS)
Granroth, Sari; Olovsson, Weine; Holmstroem, Erik; Knut, Ronny; Gorgoi, Mihaela; Svensson, Svante; Karis, Olof
2011-01-01
Advances in instrumentation regarding 3rd generation synchrotron light sources and electron spectrometers has enabled the field of high kinetic energy photoelectron spectroscopy (HIKE) (also often denoted hard X-ray photoelectron spectroscopy (HX-PES or HAXPES)). Over the last years, the amount of investigations that relies on the HIKE method has increased dramatically and can arguably be said to have given a rebirth of the interest in photoelectron spectroscopy in many areas. It is in particular the much increased mean free path at higher kinetic energies in combination with the elemental selectivity of the core level spectroscopies in general that has lead to this fact, as it makes it possible to investigate the electronic structure of materials with a substantially reduced surface sensitivity. In this review we demonstrate how HIKE can be used to investigate the interface properties in multilayer systems. Relative intensities of the core level photoelectron peaks and their chemical shifts derived from binding energy changes are found to give precise information on physico-chemical properties and quality of the buried layers. Interface roughening, including kinetic properties such as the rate of alloying, and temperature effects on the processes can be analyzed quantitatively. We will also provide an outline of the theoretical framework that is used to support the interpretation of data. We provide examples from our own investigations of multilayer systems which comprises both systems of more model character and a multilayer system very close to real applications in devices that are considered to be viable alternative to the present read head technology. The experimental data presented in this review is exclusively recorded at the BESSY-II synchrotron at the Helmholtz-Zentrum Berlin fuer Materialien und Energie. This HIKE facility is placed at the bending magnet beamline KMC-1, which makes it different from several other facilities which relies on undulators as
Energy Conservation Tests of a Coupled Kinetic-kinetic Plasma-neutral Transport Code
Energy Technology Data Exchange (ETDEWEB)
Stotler, D. P.; Chang, C. S.; Ku, S. H.; Lang, J.; Park, G.
2012-08-29
A Monte Carlo neutral transport routine, based on DEGAS2, has been coupled to the guiding center ion-electron-neutral neoclassical PIC code XGC0 to provide a realistic treatment of neutral atoms and molecules in the tokamak edge plasma. The DEGAS2 routine allows detailed atomic physics and plasma-material interaction processes to be incorporated into these simulations. The spatial pro le of the neutral particle source used in the DEGAS2 routine is determined from the uxes of XGC0 ions to the material surfaces. The kinetic-kinetic plasma-neutral transport capability is demonstrated with example pedestal fueling simulations.
Che, H.; Goldstein, M. L.; Vinas, A. F.
2014-01-01
The observed steep kinetic scale turbulence spectrum in the solar wind raises the question of how that turbulence originates. Observations of keV energetic electrons during solar quiet time suggest them as a possible source of free energy to drive kinetic turbulence. Using particle-in-cell simulations, we explore how the free energy released by an electron two-stream instability drives Weibel-like electromagnetic waves that excite wave-wave interactions. Consequently, both kinetic Alfvénic and whistler turbulence are excited that evolve through inverse and forward magnetic energy cascades.
International Nuclear Information System (INIS)
Zhang Peng; Feng Zheng-Peng; Luo Si-Qiang; Wang Zhe
2016-01-01
We investigate the influence of the interaction volume on the energy resolution of a velocity map imaging spectrometer. The simulation results show that the axial interaction size has a significant influence on the resolution. This influence is increased for a higher kinetic energy. We further show that the radial interaction size has a minor influence on the energy resolution for the electron or ion with medium energy, but it is crucial for the resolution of the electron or ion with low kinetic energy. By tracing the flight trajectories we show how the electron or ion energy resolution is influenced by the interaction size. (paper)
Energy partitioning constraints at kinetic scales in low-β turbulence
Gershman, Daniel J.; F.-Viñas, Adolfo; Dorelli, John C.; Goldstein, Melvyn L.; Shuster, Jason; Avanov, Levon A.; Boardsen, Scott A.; Stawarz, Julia E.; Schwartz, Steven J.; Schiff, Conrad; Lavraud, Benoit; Saito, Yoshifumi; Paterson, William R.; Giles, Barbara L.; Pollock, Craig J.; Strangeway, Robert J.; Russell, Christopher T.; Torbert, Roy B.; Moore, Thomas E.; Burch, James L.
2018-02-01
Turbulence is a fundamental physical process through which energy injected into a system at large scales cascades to smaller scales. In collisionless plasmas, turbulence provides a critical mechanism for dissipating electromagnetic energy. Here, we present observations of plasma fluctuations in low-β turbulence using data from NASA's Magnetospheric Multiscale mission in Earth's magnetosheath. We provide constraints on the partitioning of turbulent energy density in the fluid, ion-kinetic, and electron-kinetic ranges. Magnetic field fluctuations dominated the energy density spectrum throughout the fluid and ion-kinetic ranges, consistent with previous observations of turbulence in similar plasma regimes. However, at scales shorter than the electron inertial length, fluctuation power in electron kinetic energy significantly exceeded that of the magnetic field, resulting in an electron-motion-regulated cascade at small scales. This dominance is highly relevant for the study of turbulence in highly magnetized laboratory and astrophysical plasmas.
Determination of kinetic coefficients for proton-nucleus collisions at high energy
International Nuclear Information System (INIS)
Rizzato, C.M.
1987-01-01
From the effective proton dynamics, the approximations in the context of high energy collisions which lead to the Boltzmann equation, are established. From this equation, general expressions for the kinetic coefficients are deduced. Using a simple model, analytical expressions for kinetic coefficients are obtained. The importance of the effect of Pauli blocking is also shown. (author) [pt
On the equipartition of kinetic energy in an ideal gas mixture
International Nuclear Information System (INIS)
Peliti, L
2007-01-01
A refinement of an argument due to Maxwell for the equipartition of translational kinetic energy in a mixture of ideal gases with different masses is proposed. The argument is elementary, yet it may work as an illustration of the role of symmetry and independence postulates in kinetic theory
On the Equipartition of Kinetic Energy in an Ideal Gas Mixture
Peliti, L.
2007-01-01
A refinement of an argument due to Maxwell for the equipartition of translational kinetic energy in a mixture of ideal gases with different masses is proposed. The argument is elementary, yet it may work as an illustration of the role of symmetry and independence postulates in kinetic theory. (Contains 1 figure.)
Fibrin related antigens: assay development, clinical and kinetic studies
Energy Technology Data Exchange (ETDEWEB)
Kruskal, J B
1987-08-01
This thesis describes an assay which is able to measure and to determine the proportions of fibrin- and fibrinogen-related antigens (FRA) present in clinical samples. No assay exists at present which is capable of distinguishing between fibrin and fibrinogen degradation products concurrently and in a clinical setting. The assay may be used as a tool with which to gain further insight to pathophysiology of disorders characterized by activation of the coagulation and fibrinolytic pathways. This study provides and analysis of the FRA profiles in patients with disorders characterised by possible enhanced fibrinolytic activity. Studies have been undertaken on patients with acute and chronic liver diseases, on patients with the various syndromes of coronary artery disease and on patients with insulin-dependent diabetes mellitus with and without evidence of microvascular disease. Certain observations made it evident that further studies were required in order to explain previously undocumented fibrinolytic abnormalities in certain patient groups. Data obtained from patients with liver disease provided information compatible with the activation of their fibrinolytic pathways. The initial scope of this study was then extended to further investigate the deranged haemostatic mechanisms in patients with severe liver diseases. Kinetic studies were performed which required the development of specific technology to be able to measure certain previously undertermined parameters. Mathematical models describing the rates of fibrin formation and lysis were developed for human studies. Fibrin-derived D-dimer was radiolabelled and its validity as and intravenous tracer and maker of fibrin degradation established.
Making waves: Kinetic processes controlling surface evolution during low energy ion sputtering
International Nuclear Information System (INIS)
Chan, W.L.; Chason, Eric
2007-01-01
When collimated beams of low energy ions are used to bombard materials, the surface often develops a periodic pattern or ''ripple'' structure. Different types of patterns are observed to develop under different conditions, with characteristic features that depend on the substrate material, the ion beam parameters, and the processing conditions. Because the patterns develop spontaneously, without applying any external mask or template, their formation is the expression of a dynamic balance among fundamental surface kinetic processes, e.g., erosion of material from the surface, ion-induced defect creation, and defect-mediated evolution of the surface morphology. In recent years, a comprehensive picture of the different kinetic mechanisms that control the different types of patterns that form has begun to emerge. In this article, we provide a review of different mechanisms that have been proposed and how they fit together in terms of the kinetic regimes in which they dominate. These are grouped into regions of behavior dominated by the directionality of the ion beam, the crystallinity of the surface, the barriers to surface roughening, and nonlinear effects. In sections devoted to each type of behavior, we relate experimental observations of patterning in these regimes to predictions of continuum models and to computer simulations. A comparison between theory and experiment is used to highlight strengths and weaknesses in our understanding. We also discuss the patterning behavior that falls outside the scope of the current understanding and opportunities for advancement
International Nuclear Information System (INIS)
Veluswamy, Hari Prakash; Kumar, Asheesh; Kumar, Rajnish; Linga, Praveen
2017-01-01
Highlights: • Innovative combinatorial hybrid approach to reduce nucleation stochasticity and enhance hydrate growth. • Methane hydrate growth curves are similar in UTR and STR configurations in presence of leucine. • Amalgamation of stirred (STR) and unstirred (UTR) configuration is demonstrated. • Reliable method for scale up and commercial production of Solidified Natural Gas (SNG). - Abstract: Natural gas storage in clathrate hydrates or solidified natural gas (SNG) offers the safest, cleanest and the most compact mode of storage aided by the relative ease in natural gas (NG) recovery with minimal cost compared to known conventional methods of NG storage. The stochastic nature of hydrate nucleation and the slow kinetics of hydrate growth are major challenges that needs to be addressed on the SNG production side. A deterministic and fast nucleation coupled with rapid crystallization kinetics would empower this beneficial technology for commercial application. We propose a hybrid combinatorial approach of methane hydrate formation utilizing the beneficial aspect of environmentally benign amino acid (leucine) as a kinetic promoter by combining stirred and unstirred reactor operation. This hybrid approach is simple, can easily be implemented and scaled-up to develop an economical SNG technology for efficient storage of natural gas on a large scale. Added benefits include the minimal energy requirement during hydrate growth resulting in overall cost reduction for SNG technology.
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Kok Gnee CHUA
2016-05-01
Full Text Available As an ecological source of renewable energy, the available kinetic energy of rainfall is not trifling, especially in tropical countries at the equators. The research on the use of piezoelectric transducer to harvest raindrop kinetic energy is gaining more and more attention recently. This article reviews the state-of-the-art energy harvesting technology from the conversion of raindrop kinetic energy using piezoelectric transducers as well as its interface circuits for vibration-based energy harvesters. Performance of different types of piezoelectric harvesters in terms of power output, area power density and energy conversion efficiency are compared. Summaries of key problems and suggestions on the optimization of the performance of the piezoelectric harvesters are also provided for future works.
Energy Technology Data Exchange (ETDEWEB)
Deng, De-Ming; Chang, Cheng-Hung [Institute of Physics, National Chiao Tung University, Hsinchu 300, Taiwan (China)
2015-05-14
Conventional studies of biomolecular behaviors rely largely on the construction of kinetic schemes. Since the selection of these networks is not unique, a concern is raised whether and under which conditions hierarchical schemes can reveal the same experimentally measured fluctuating behaviors and unique fluctuation related physical properties. To clarify these questions, we introduce stochasticity into the traditional lumping analysis, generalize it from rate equations to chemical master equations and stochastic differential equations, and extract the fluctuation relations between kinetically and thermodynamically equivalent networks under intrinsic and extrinsic noises. The results provide a theoretical basis for the legitimate use of low-dimensional models in the studies of macromolecular fluctuations and, more generally, for exploring stochastic features in different levels of contracted networks in chemical and biological kinetic systems.
Deng, De-Ming; Chang, Cheng-Hung
2015-05-14
Conventional studies of biomolecular behaviors rely largely on the construction of kinetic schemes. Since the selection of these networks is not unique, a concern is raised whether and under which conditions hierarchical schemes can reveal the same experimentally measured fluctuating behaviors and unique fluctuation related physical properties. To clarify these questions, we introduce stochasticity into the traditional lumping analysis, generalize it from rate equations to chemical master equations and stochastic differential equations, and extract the fluctuation relations between kinetically and thermodynamically equivalent networks under intrinsic and extrinsic noises. The results provide a theoretical basis for the legitimate use of low-dimensional models in the studies of macromolecular fluctuations and, more generally, for exploring stochastic features in different levels of contracted networks in chemical and biological kinetic systems.
Kinetic energy density and agglomerate abrasion rate during blending of agglomerates into powders.
Willemsz, Tofan A; Hooijmaijers, Ricardo; Rubingh, Carina M; Tran, Thanh N; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees
2012-01-23
Problems related to the blending of a cohesive powder with a free flowing bulk powder are frequently encountered in the pharmaceutical industry. The cohesive powder often forms lumps or agglomerates which are not dispersed during the mixing process and are therefore detrimental to blend uniformity. Achieving sufficient blend uniformity requires that the blending conditions are able to break up agglomerates, which is often an abrasion process. This study was based on the assumption that the abrasion rate of agglomerates determines the required blending time. It is shown that the kinetic energy density of the moving powder bed is a relevant parameter which correlates with the abrasion rate of agglomerates. However, aspects related to the strength of agglomerates should also be considered. For this reason the Stokes abrasion number (St(Abr)) has been defined. This parameter describes the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. The St(Abr) number is shown to predict the abrasion potential of agglomerates in the dry-mixing process. It appeared possible to include effects of filler particle size and impeller rotational rate into this concept. A clear relationship between abrasion rate of agglomerates and the value of St(Abr) was demonstrated. Copyright © 2011 Elsevier B.V. All rights reserved.
Scott, Robert B.; Arbic, Brian K.; Chassignet, Eric P.; Coward, Andrew C.; Maltrud, Mathew; Merryfield, William J.; Srinivasan, Ashwanth; Varghese, Anson
2010-01-01
We compare the total kinetic energy (TKE) in four global eddying ocean circulation simulations with a global dataset of over 5000, quality controlled, moored current meter records. At individual mooring sites, there was considerable scatter between
Turbulent kinetic energy balance measurements in the wake of a low-pressure turbine blade
International Nuclear Information System (INIS)
Sideridis, A.; Yakinthos, K.; Goulas, A.
2011-01-01
The turbulent kinetic energy budget in the wake generated by a high lift, low-pressure two-dimensional blade cascade of the T106 profile was investigated experimentally using hot-wire anemometry. The purpose of this study is to examine the transport mechanism of the turbulent kinetic energy and provide validation data for turbulence modeling. Point measurements were conducted on a high spatial resolution, two-dimensional grid that allowed precise derivative calculations. Positioning of the probe was achieved using a high accuracy traversing mechanism. The turbulent kinetic energy (TKE) convection, production, viscous diffusion and turbulent diffusion were all obtained directly from experimental measurements. Dissipation and pressure diffusion were calculated indirectly using techniques presented and validated by previous investigators. Results for all terms of the turbulent kinetic energy budget are presented and discussed in detail in the present work.
Data on kinetic, energy and emission performance of biodiesel from waste frying oil
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Silverio Catureba da Silva Filho
2018-06-01
Full Text Available The data presented in this article are related to the research article “Environmental and techno-economic considerations on biodiesel production from waste frying oil in São Paulo city” (Silva Filho et al., 2018 [1]. This article presents the variation of the concentration of waste frying oil (WFO with the reaction time and temperature during the transesterification of WTOs collected in the residences and restaurants of the city of São Paulo. Then, the biodiesel samples were mixed with the S-10 diesel oil in order to obtain the B10, B20, B30, B40, B50, B75 and B100 blends, which were tested in a diesel engine and their power, fuel consumption and gas emissions (CO, CO2 and SO2 have been measured to verify their greenhouse effect and energy efficiency. Keywords: Biodiesel, Kinetic curves, Greenhouse gas emission, Energy efficiency
International Nuclear Information System (INIS)
De-Santiago, Josue; Cervantes-Cota, Jorge L.
2011-01-01
We study a unification model for dark energy, dark matter, and inflation with a single scalar field with noncanonical kinetic term. In this model, the kinetic term of the Lagrangian accounts for the dark matter and dark energy, and at early epochs, a quadratic potential accounts for slow roll inflation. The present work is an extension to the work by Bose and Majumdar [Phys. Rev. D 79, 103517 (2009).] with a more general kinetic term that was proposed by Chimento in Phys. Rev. D 69, 123517 (2004). We demonstrate that the model is viable at the background and linear perturbation levels.
International Nuclear Information System (INIS)
Garcia-Aldea, David; Alvarellos, J. E.
2008-01-01
We propose a kinetic energy density functional scheme with nonlocal terms based on the von Weizsaecker functional, instead of the more traditional approach where the nonlocal terms have the structure of the Thomas-Fermi functional. The proposed functionals recover the exact kinetic energy and reproduce the linear response function of homogeneous electron systems. In order to assess their quality, we have tested the total kinetic energies as well as the kinetic energy density for atoms. The results show that these nonlocal functionals give as good results as the most sophisticated functionals in the literature. The proposed scheme for constructing the functionals means a step ahead in the field of fully nonlocal kinetic energy functionals, because they are capable of giving better local behavior than the semilocal functionals, yielding at the same time accurate results for total kinetic energies. Moreover, the functionals enjoy the possibility of being evaluated as a single integral in momentum space if an adequate reference density is defined, and then quasilinear scaling for the computational cost can be achieved
Kinetic energy definition in velocity Verlet integration for accurate pressure evaluation
Jung, Jaewoon; Kobayashi, Chigusa; Sugita, Yuji
2018-04-01
In molecular dynamics (MD) simulations, a proper definition of kinetic energy is essential for controlling pressure as well as temperature in the isothermal-isobaric condition. The virial theorem provides an equation that connects the average kinetic energy with the product of particle coordinate and force. In this paper, we show that the theorem is satisfied in MD simulations with a larger time step and holonomic constraints of bonds, only when a proper definition of kinetic energy is used. We provide a novel definition of kinetic energy, which is calculated from velocities at the half-time steps (t - Δt/2 and t + Δt/2) in the velocity Verlet integration method. MD simulations of a 1,2-dispalmitoyl-sn-phosphatidylcholine (DPPC) lipid bilayer and a water box using the kinetic energy definition could reproduce the physical properties in the isothermal-isobaric condition properly. We also develop a multiple time step (MTS) integration scheme with the kinetic energy definition. MD simulations with the MTS integration for the DPPC and water box systems provided the same quantities as the velocity Verlet integration method, even when the thermostat and barostat are updated less frequently.
Kinetic energy definition in velocity Verlet integration for accurate pressure evaluation.
Jung, Jaewoon; Kobayashi, Chigusa; Sugita, Yuji
2018-04-28
In molecular dynamics (MD) simulations, a proper definition of kinetic energy is essential for controlling pressure as well as temperature in the isothermal-isobaric condition. The virial theorem provides an equation that connects the average kinetic energy with the product of particle coordinate and force. In this paper, we show that the theorem is satisfied in MD simulations with a larger time step and holonomic constraints of bonds, only when a proper definition of kinetic energy is used. We provide a novel definition of kinetic energy, which is calculated from velocities at the half-time steps (t - Δt/2 and t + Δt/2) in the velocity Verlet integration method. MD simulations of a 1,2-dispalmitoyl-sn-phosphatidylcholine (DPPC) lipid bilayer and a water box using the kinetic energy definition could reproduce the physical properties in the isothermal-isobaric condition properly. We also develop a multiple time step (MTS) integration scheme with the kinetic energy definition. MD simulations with the MTS integration for the DPPC and water box systems provided the same quantities as the velocity Verlet integration method, even when the thermostat and barostat are updated less frequently.
Hypovalency--a kinetic-energy density description of a 4c-2e bond.
Jacobsen, Heiko
2009-06-07
A bond descriptor based on the kinetic energy density, the localized-orbital locator (LOL), is used to characterize the nature of the chemical bond in electron deficient multi-center bonds. The boranes B(2)H(6), B(4)H(4), B(4)H(10), [B(6)H(6)](2-), and [B(6)H(7)](-) serve as prototypical examples of hypovalent 3c-2e and 4c-2e bonding. The kinetic energy density is derived from a set of Kohn-Sham orbitals obtained from pure density functional calculations (PBE/TZVP), and the topology of LOL is analyzed in terms of (3,-3) attractors (Gamma). The B-B-B and B-H-B 3c-2e, and the B-B-H-B 4c-2e bonding situations are defined by their own characteristic LOL profiles. The presence of one attractor in relation to the three or four atoms that are engaged in electron deficient bonding provides sufficient indication of the type of 3c-2e or 4c-2e bond present. For the 4c-2e bond in [B(6)H(7)](-) the LOL analysis is compared to results from an experimental QTAIM study.
Isenmann, Gilles; Dufresne, Matthieu; Vazquez, José; Mose, Robert
2017-10-01
The purpose of this study is to develop and validate a numerical tool for evaluating the performance of a settling basin regarding the trapping of suspended matter. The Euler-Lagrange approach was chosen to model the flow and sediment transport. The numerical model developed relies on the open source library OpenFOAM ® , enhanced with new particle/wall interaction conditions to limit sediment deposition in zones with favourable hydrodynamic conditions (shear stress, turbulent kinetic energy). In particular, a new relation is proposed for calculating the turbulent kinetic energy threshold as a function of the properties of each particle (diameter and density). The numerical model is compared to three experimental datasets taken from the literature and collected for scale models of basins. The comparison of the numerical and experimental results permits concluding on the model's capacity to predict the trapping of particles in a settling basin with an absolute error in the region of 5% when the sediment depositions occur over the entire bed. In the case of sediment depositions localised in preferential zones, their distribution is reproduced well by the model and trapping efficiency is evaluated with an absolute error in the region of 10% (excluding cases of particles with very low density).
International Nuclear Information System (INIS)
Yoon, Hong Min; Kondaraju, Sasidhar; Lee, Jung Shin; Suh, Youngho; Lee, Joonho H.; Lee, Joon Sang
2017-01-01
Highlights: • Contact line forces, including friction and spreading forces are directly calculated. • Overall trends of variations in contact line forces during droplet spreading process show characteristics of contact line forces. • Detail relations of contact line forces and atomic kinetics in the contact line provide a clear evidence of the possible energy dissipation mechanism in droplet spreading process. - Abstract: Recent studies have revealed that contact line forces play an important role in the droplet spreading process. Despite their significance, the physics related to them has been studied only indirectly and the effect of contact line forces is still being disputed. We performed a molecular dynamics simulation and mimicked the droplet spreading process at the nanoscale. Based on the results of the simulation, the contact line forces were directly calculated. We found that the forces acting on the bulk and the contact line region showed different trends. Distinct positive and negative forces, contact line spreading, and friction forces were observed near the contact line. We also observed a strong dependency of the atomic kinetics in the contact line region on the variations in the contact line forces. The atoms of the liquid in the contact line region lost their kinetic energy due to the contact line friction force and became partially immobile on the solid surface. The results of the current study will be useful for understanding the role of the contact line forces on the kinetic energy dissipation in the contact line region.
Energy Technology Data Exchange (ETDEWEB)
Yoon, Hong Min [Department of Mechanical Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Kondaraju, Sasidhar [Department of Mechanical Science, Indian Institute of Technology Bhubaneswar, Bhubaneswar, Odisha 751013 (India); Lee, Jung Shin [Department of Mechanical Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Suh, Youngho; Lee, Joonho H. [Samsung Electronics, Mechatronics R& D Center, Hwaseong-si, Gyeonggi-do 445-330 (Korea, Republic of); Lee, Joon Sang, E-mail: joonlee@yonsei.ac.kr [Department of Mechanical Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)
2017-07-01
Highlights: • Contact line forces, including friction and spreading forces are directly calculated. • Overall trends of variations in contact line forces during droplet spreading process show characteristics of contact line forces. • Detail relations of contact line forces and atomic kinetics in the contact line provide a clear evidence of the possible energy dissipation mechanism in droplet spreading process. - Abstract: Recent studies have revealed that contact line forces play an important role in the droplet spreading process. Despite their significance, the physics related to them has been studied only indirectly and the effect of contact line forces is still being disputed. We performed a molecular dynamics simulation and mimicked the droplet spreading process at the nanoscale. Based on the results of the simulation, the contact line forces were directly calculated. We found that the forces acting on the bulk and the contact line region showed different trends. Distinct positive and negative forces, contact line spreading, and friction forces were observed near the contact line. We also observed a strong dependency of the atomic kinetics in the contact line region on the variations in the contact line forces. The atoms of the liquid in the contact line region lost their kinetic energy due to the contact line friction force and became partially immobile on the solid surface. The results of the current study will be useful for understanding the role of the contact line forces on the kinetic energy dissipation in the contact line region.
Shantappa, A.; Hanagodimath, S. M.
2014-01-01
Effective atomic numbers, electron densities of some vitamins (Retinol, Riboflavin, Niacin, Biotin, Folic acid, Cobalamin, Phylloquinone and Flavonoids) composed of C, H, O, N, Co, P and S have been calculated for total and partial photon interactions by the direct method for energy range 1 keV-100 GeV by using WinXCOM and kinetic energy released in matter (Kerma) relative to air is calculated in energy range of 1 keV-20 MeV. Change in effective atomic number and electron density with energy is calculated for all photon interactions. Variation of photon mass attenuation coefficients with energy are shown graphically only for total photon interaction. It is observed that change in mass attenuation coefficient with composition of different chemicals is very large below 100 keV and moderate between 100 keV and 10 MeV and negligible above 10 MeV. Behaviour of vitamins is almost indistinguishable except biotin and cobalamin because of large range of atomic numbers from 1(H) to 16 (S) and 1(H) to 27(Co) respectively. K a value shows a peak due to the photoelectric effect around K-absorption edge of high- Z constituent of compound for biotin and cobalamin.
Energy Transfer Kinetics and Dynamics of Relevance to Iodine Lasers
National Research Council Canada - National Science Library
Heaven, Michael C
2001-01-01
...). Energy transfer between I(2 P(1/2)) and 02(X) has been studied in detail. Rate constants for electronic energy transfer and nuclear spin relaxation were measured over the temperature range from 150-300K...
Bounds on poloidal kinetic energy in plane layer convection
Tilgner, A.
2017-12-01
A numerical method is presented that conveniently computes upper bounds on heat transport and poloidal energy in plane layer convection for infinite and finite Prandtl numbers. The bounds obtained for the heat transport coincide with earlier results. These bounds imply upper bounds for the poloidal energy, which follow directly from the definitions of dissipation and energy. The same constraints used for computing upper bounds on the heat transport lead to improved bounds for the poloidal energy.
The energy-momentum tensor for the linearized Maxwell-Vlasov and kinetic guiding center theories
International Nuclear Information System (INIS)
Pfirsch, D.; Morrison, P.J.; Texas Univ., Austin
1990-02-01
A modified Hamilton-Jacobi formalism is introduced as a tool to obtain the energy-momentum and angular-momentum tensors for any kind of nonlinear or linearized Maxwell-collisionless kinetic theories. The emphasis is on linearized theories, for which these tensors are derived for the first time. The kinetic theories treated - which need not be the same for all particle species in a plasma - are the Vlasov and kinetic guiding center theories. The Hamiltonian for the guiding center motion is taken in the form resulting from Dirac's constraint theory for non-standard Lagrangian systems. As an example of the Maxwell-kinetic guiding center theory, the second-order energy for a perturbed homogeneous magnetized plasma is calculated with initially vanishing field perturbations. The expression obtained is compared with the corresponding one of Maxwell-Vlasov theory. (orig.)
The energy-momentum tensor for the linearized Maxwell-Vlasov and kinetic guiding center theories
International Nuclear Information System (INIS)
Pfirsch, D.; Morrison, P.J.
1990-02-01
A modified Hamilton-Jacobi formalism is introduced as a tool to obtain the energy-momentum and angular-momentum tensors for any king of nonlinear or linearized Maxwell-collisionless kinetic theories. The emphasis is on linearized theories, for which these tensors are derived for the first time. The kinetic theories treated --- which need not be the same for all particle species in a plasma --- are the Vlasov and kinetic guiding center theories. The Hamiltonian for the guiding center motion is taken in the form resulting from Dirac's constraint theory for non-standard Lagrangian systems. As an example of the Maxwell-kinetic guiding center theory, the second-order energy for a perturbed homogeneous magnetized plasma is calculated with initially vanishing field perturbations. The expression obtained is compared with the corresponding one of Maxwell-Vlasov theory. 11 refs
A static analysis method to determine the availability of kinetic energy from wind turbines
Rawn, B.G.; Gibescu, M.; Kling, W.L.
2010-01-01
This paper introduces definitions and an analysis method for estimating how much kinetic energy can be made available for inertial response from a wind turbine over a year, and how much energy capture must be sacrificed to do so. The analysis is based on the static characteristics of wind turbines,
International Nuclear Information System (INIS)
Amovilli, C; March, N H
2012-01-01
Utilizing the earlier work of Holas et al (2003 Phys. Lett. A 310 451) and the more recent contribution of Akbari et al (2009 Phys. Rev. A 80 032509), we construct an integral equation for the relative motion (RM) contribution t RM (r) to the correlated kinetic energy density for modelling two-electron atoms with harmonic confinement but arbitrary interparticle interaction. It is stressed that t RM = t RM [f(G)], where f(G) is the atomic scattering factor: the Fourier transform of the density ρ(r). As a simple illustrative example of this functional relation for the correlated kinetic energy density, the harmonic Moshinsky case is investigated, the scattering factor then having a Gaussian form. (paper)
Kinetics of cluster-related defects in silicon sensors irradiated with monoenergetic electrons
Radu, R.; Pintilie, I.; Makarenko, L. F.; Fretwurst, E.; Lindstroem, G.
2018-04-01
This work focuses on the kinetic mechanisms responsible for the annealing behavior of radiation cluster-related defects with impact on the electrical performance of silicon sensors. Such sensors were manufactured on high resistivity n-type standard float-zone (STFZ) and oxygen enriched float-zone (DOFZ) material and had been irradiated with mono-energetic electrons of 3.5 MeV energy and fluences of 3 × 1014 cm-2 and 6 × 1014 cm-2. After irradiation, the samples were subjected either to isochronal or isothermal heat treatments in the temperature range from 80 °C to 300 °C. The specific investigated defects are a group of three deep acceptors [H(116 K), H(140 K), and H(152 K)] with energy levels in the lower half of the band gap and a shallow donor E(30 K) with a level at 0.1 eV below the conduction band. The stability and kinetics of these defects at high temperatures are discussed on the basis of the extracted activation energies and frequency factors. The annealing of the H defects takes place similarly in both types of materials, suggesting a migration rather than a dissociation mechanism. On the contrary, the E(30 K) defect shows a very different annealing behavior, being stable in STFZ even at 300 °C, but annealing-out quickly in DOFZ material at temperatures higher than 200 °C , with a high frequency factor of the order of 1013 s-1. Such a behavior rules out a dissociation process, and the different annealing behavior is suggested to be related to a bistable behavior of the defect.
Assessment of Kinetic Tidal Energy Resources Using SELFE
Directory of Open Access Journals (Sweden)
Manasa Ranjan Behera
2014-09-01
Full Text Available An investigation is carried out to study the theoretical tidal stream energy resource in the Singapore Strait to support the search for renewable energy in the effort to reduce the carbon footprints in the Southeast Asia. The tidal hydrodynamics in the Singapore Strait has been simulated using a Semi-implicit Eulerian-Lagrangian Finite-Element (SELFE model solving the 3D shallow water equations with Boussinesq approximations. Potential sites, with high tidal current (2.5 m/s and suitable for Tidal Energy Converter (TEC array installation to generate sustainable energy, have been identified. Further, various operational factors for installation of Tidal Energy Converters are considered before computing the theoretical power output for a typical TEC array. An approximate estimation of the possible theoretical power extraction from a TEC array shows an energy potential of up to 4.36% of the total energy demand of Singapore in 2011. Thus, the study suggests a detailed investigation of potential sites to quantify the total tidal stream energy potential in the Singapore Strait.
Nonextensive kinetic theory and H-theorem in general relativity
Santos, A. P.; Silva, R.; Alcaniz, J. S.; Lima, J. A. S.
2017-11-01
The nonextensive kinetic theory for degenerate quantum gases is discussed in the general relativistic framework. By incorporating nonadditive modifications in the collisional term of the relativistic Boltzmann equation and entropy current, it is shown that Tsallis entropic framework satisfies a H-theorem in the presence of gravitational fields. Consistency with the 2nd law of thermodynamics is obtained only whether the entropic q-parameter lies in the interval q ∈ [ 0 , 2 ] . As occurs in the absence of gravitational fields, it is also proved that the local collisional equilibrium is described by the extended Bose-Einstein (Fermi-Dirac) q-distributions.
Nonlocal exchange and kinetic-energy density functionals for electronic systems
International Nuclear Information System (INIS)
Glossman, M.D.; Rubio, A.; Balbas, L.C.; Alonso, J.A.
1992-01-01
The nonlocal weighted density approximation (WDA) to the exchange and kinetic-energy functionals of many electron systems proposed several years ago by Alonso and Girifalco is used to compute, within the framework of density functional theory, the ground-state electronic density and total energy of noble gas atoms and of neutral jellium-like sodium clusters containing up to 500 atoms. These results are compared with analogous calculations using the well known Thomas-Fermi-Weizsacker-Dirac (TFWD) approximations for the kinetic (TFW) and exchange (D) energy density functionals. An outstanding improvement of the total and exchange energies, of the density at the nucleus and of the expectation values is obtained for atoms within the WDA scheme. For sodium clusters the authors notice a sizeable contribution of the nonlocal effects to the total energy and to the density profiles. In the limit of very large clusters these effects should affect the surface energy of the bulk metal
Predicting rainfall erosivity by momentum and kinetic energy in Mediterranean environment
Carollo, Francesco G.; Ferro, Vito; Serio, Maria A.
2018-05-01
Rainfall erosivity is an index that describes the power of rainfall to cause soil erosion and it is used around the world for assessing and predicting soil loss on agricultural lands. Erosivity can be represented in terms of both rainfall momentum and kinetic energy, both calculated per unit time and area. Contrasting results on the representativeness of these two variables are available: some authors stated that momentum and kinetic energy are practically interchangeable in soil loss estimation while other found that kinetic energy is the most suitable expression of rainfall erosivity. The direct and continuous measurements of momentum and kinetic energy by a disdrometer allow also to establish a relationship with rainfall intensity at the study site. At first in this paper a comparison between the momentum-rainfall intensity relationships measured at Palermo and El Teularet by an optical disdrometer is presented. For a fixed rainfall intensity the measurements showed that the rainfall momentum values measured at the two experimental sites are not coincident. However both datasets presented a threshold value of rainfall intensity over which the rainfall momentum assumes a quasi-constant value. Then the reliability of a theoretically deduced relationship, linking momentum, rainfall intensity and median volume diameter, is positively verified using measured raindrop size distributions. An analysis to assess which variable, momentum or kinetic energy per unit area and time, is the best predictor of erosivity in Italy and Spain was also carried out. This investigation highlighted that the rainfall kinetic energy per unit area and time can be substituted by rainfall momentum as index for estimating the rainfall erosivity, and this result does not depend on the site where precipitation occurs. Finally, rainfall intensity measurements and soil loss data collected from the bare plots equipped at Sparacia experimental area were used to verify the reliability of some
Connecting the kinetics and energy landscape of tRNA translocation on the ribosome.
Directory of Open Access Journals (Sweden)
Paul C Whitford
Full Text Available Functional rearrangements in biomolecular assemblies result from diffusion across an underlying energy landscape. While bulk kinetic measurements rely on discrete state-like approximations to the energy landscape, single-molecule methods can project the free energy onto specific coordinates. With measures of the diffusion, one may establish a quantitative bridge between state-like kinetic measurements and the continuous energy landscape. We used an all-atom molecular dynamics simulation of the 70S ribosome (2.1 million atoms; 1.3 microseconds to provide this bridge for specific conformational events associated with the process of tRNA translocation. Starting from a pre-translocation configuration, we identified sets of residues that collectively undergo rotary rearrangements implicated in ribosome function. Estimates of the diffusion coefficients along these collective coordinates for translocation were then used to interconvert between experimental rates and measures of the energy landscape. This analysis, in conjunction with previously reported experimental rates of translocation, provides an upper-bound estimate of the free-energy barriers associated with translocation. While this analysis was performed for a particular kinetic scheme of translocation, the quantitative framework is general and may be applied to energetic and kinetic descriptions that include any number of intermediates and transition states.
Protasevich, Alexander E.; Nikitin, Andrei V.
2018-01-01
In this work, we propose an algorithm for calculating the matrix elements of the kinetic energy operator for tetrahedral molecules. This algorithm uses the dependent six-angle coordinates (6A) and takes into account the full symmetry of molecules. Unlike A.V. Nikitin, M. Rey, and Vl. G. Tyuterev who operate with the kinetic energy operator only in Radau orthogonal coordinates, we consider a general case. The matrix elements are shown to be a sum of products of one-dimensional integrals.
International Congress on Energy Efficiency and Energy Related Materials
Bahsi, Zehra; Ozer, Mehmet; ENEFM2013
2014-01-01
The International Congress on Energy Efficiency and Energy Related Materials (ENEFM2013) was held on 9-12 October, 2013. This three-day congress focused on the latest developments of sustainable energy technologies, materials for sustainable energy applications and environmental & economic perspectives of energy. These proceedings include 63 peer reviewed technical papers, submitted from leading academic and research institutions from over 23 countries, representing some of the most cutting edge research available. The papers included were presented at the congress in the following sessions: General Issues Wind Energy Solar Energy Nuclear Energy Biofuels and Bioenergy Energy Storage Energy Conservation and Efficiency Energy in Buildings Economical and Environmental Issues Environment Energy Requirements Economic Development Materials for Sustainable Energy Hydrogen Production and Storage Photovoltaic Cells Thermionic Converters Batteries and Superconductors Phase Change Materials Fuel Cells Supercon...
Kinetic energy storage of off-peak electricity
International Nuclear Information System (INIS)
Simpson, L.A.; Oldaker, I.E.; Stermscheg, J.
1975-09-01
The concept of using large flywheels to store off-peak electricity has been considered. The development of high strength composite materials has made possible improvements in the energy storage capacity of such devices. The problems involved in designing large flywheels and their economic advantages over alternative means of energy storage are discussed. The economic arguments are based on the present or near future capabilities and costs of structural composite materials. The flywheel costs turn out to be considerably higher than for many alternative schemes including advanced batteries, gas turbine generators and pumped storage schemes. (author)
Assessment of Kinetic Tidal Energy Resources Using SELFE
Manasa Ranjan Behera; Pavel Tkalich
2014-01-01
An investigation is carried out to study the theoretical tidal stream energy resource in the Singapore Strait to support the search for renewable energy in the effort to reduce the carbon footprints in the Southeast Asia. The tidal hydrodynamics in the Singapore Strait has been simulated using a Semi-implicit Eulerian-Lagrangian Finite-Element (SELFE) model solving the 3D shallow water equations with Boussinesq approximations. Potential sites, with high tidal current (2.5 m/s) and suitable fo...
The total kinetic energy release in the fast neutron-induced fission of {sup 232}Th
Energy Technology Data Exchange (ETDEWEB)
King, Jonathan; Yanez, Ricardo; Loveland, Walter; Barrett, J. Spencer; Oscar, Breland [Oregon State University, Dept. of Chemistry, Corvallis, OR (United States); Fotiades, Nikolaos; Tovesson, Fredrik; Young Lee, Hye [Los Alamos National Laboratory, Physics Division, Los Alamos, NM (United States)
2017-12-15
The post-emission total kinetic energy release (TKE) in the neutron-induced fission of {sup 232}Th was measured (using white spectrum neutrons from LANSCE) for neutron energies from E{sub n} = 3 to 91 MeV. In this energy range the average post-neutron total kinetic energy release decreases from 162.3 ± 0.3 at E{sub n} = 3 MeV to 154.9 ± 0.3 MeV at E{sub n} = 91 MeV. Analysis of the fission mass distributions indicates that the decrease in TKE with increasing neutron energy is a combination of increasing yields of symmetric fission (which has a lower associated TKE) and a decrease in the TKE release in asymmetric fission. (orig.)
Bio-kinetic energy harvesting using electroactive polymers
Slade, Jeremiah R.; Bowman, Jeremy; Kornbluh, Roy
2012-06-01
In hybrid vehicles, electric motors are used on each wheel to not only propel the car but also to decelerate the car by acting as generators. In the case of the human body, muscles spend about half of their time acting as a brake, absorbing energy, or doing what is known as negative work. Using dielectric elastomers it is possible to use the "braking" phases of walking to generate power without restricting or fatiguing the Warfighter. Infoscitex and SRI have developed and demonstrated methods for using electroactive polymers (EAPs) to tap into the negative work generated at the knee during the deceleration phase of the human gait cycle and convert it into electrical power that can be used to support wearable information systems, including display and communication technologies. The specific class of EAP that has been selected for these applications is termed dielectric elastomers. Because dielectric elastomers dissipate very little mechanical energy into heat, greater amounts of energy can be converted into electricity than by any other method. The long term vision of this concept is to have EAP energy harvesting cells located in components of the Warfighter ensemble, such as the boot uppers, knee pads and eventually even the clothing itself. By properly locating EAPs at these sites it will be possible to not only harvest power from the negative work phase but to actually reduce the amount of work done by the Warfighter's muscles during this phase, thereby reducing fatigue and minimizing the forces transmitted to the joints.
VerHulst, Claire; Meneveau, Charles
2014-02-01
In this study, we address the question of how kinetic energy is entrained into large wind turbine arrays and, in particular, how large-scale flow structures contribute to such entrainment. Previous research has shown this entrainment to be an important limiting factor in the performance of very large arrays where the flow becomes fully developed and there is a balance between the forcing of the atmospheric boundary layer and the resistance of the wind turbines. Given the high Reynolds numbers and domain sizes on the order of kilometers, we rely on wall-modeled large eddy simulation (LES) to simulate turbulent flow within the wind farm. Three-dimensional proper orthogonal decomposition (POD) analysis is then used to identify the most energetic flow structures present in the LES data. We quantify the contribution of each POD mode to the kinetic energy entrainment and its dependence on the layout of the wind turbine array. The primary large-scale structures are found to be streamwise, counter-rotating vortices located above the height of the wind turbines. While the flow is periodic, the geometry is not invariant to all horizontal translations due to the presence of the wind turbines and thus POD modes need not be Fourier modes. Differences of the obtained modes with Fourier modes are documented. Some of the modes are responsible for a large fraction of the kinetic energy flux to the wind turbine region. Surprisingly, more flow structures (POD modes) are needed to capture at least 40% of the turbulent kinetic energy, for which the POD analysis is optimal, than are needed to capture at least 40% of the kinetic energy flux to the turbines. For comparison, we consider the cases of aligned and staggered wind turbine arrays in a neutral atmospheric boundary layer as well as a reference case without wind turbines. While the general characteristics of the flow structures are robust, the net kinetic energy entrainment to the turbines depends on the presence and relative
Kinetic-energy induced smoothening and delay of epitaxial breakdown in pulsed-laser deposition
International Nuclear Information System (INIS)
Shin, Byungha; Aziz, Michael J.
2007-01-01
We have isolated the effect of kinetic energy of depositing species from the effect of flux pulsing during pulsed-laser deposition (PLD) on surface morphology evolution of Ge(001) homoepitaxy at low temperature (100 deg. C). Using a dual molecular beam epitaxy (MBE) PLD chamber, we compare morphology evolution from three different growth methods under identical experimental conditions except for the differing nature of the depositing flux: (a) PLD with average kinetic energy 300 eV (PLD-KE); (b) PLD with suppressed kinetic energy comparable to thermal evaporation energy (PLD-TH); and (c) MBE. The thicknesses at which epitaxial breakdown occurs are ranked in the order PLD-KE>MBE>PLD-TH; additionally, the surface is smoother in PLD-KE than in MBE. The surface roughness of the films grown by PLD-TH cannot be compared due to the early epitaxial breakdown. These results demonstrate convincingly that kinetic energy is more important than flux pulsing in the enhancement of epitaxial growth, i.e., the reduction in roughness and the delay of epitaxial breakdown
Energy Transfer and Dual Cascade in Kinetic Magnetized Plasma Turbulence
International Nuclear Information System (INIS)
Plunk, G. G.; Tatsuno, T.
2011-01-01
The question of how nonlinear interactions redistribute the energy of fluctuations across available degrees of freedom is of fundamental importance in the study of turbulence and transport in magnetized weakly collisional plasmas, ranging from space settings to fusion devices. In this Letter, we present a theory for the dual cascade found in such plasmas, which predicts a range of new behavior that distinguishes this cascade from that of neutral fluid turbulence. These phenomena are explained in terms of the constrained nature of spectral transfer in nonlinear gyrokinetics. Accompanying this theory are the first observations of these phenomena, obtained via direct numerical simulations using the gyrokinetic code AstroGK. The basic mechanisms that are found provide a framework for understanding the turbulent energy transfer that couples scales both locally and nonlocally.
Energy Transfer and Dual Cascade in Kinetic Magnetized Plasma Turbulence
Plunk, G. G.; Tatsuno, T.
2011-04-01
The question of how nonlinear interactions redistribute the energy of fluctuations across available degrees of freedom is of fundamental importance in the study of turbulence and transport in magnetized weakly collisional plasmas, ranging from space settings to fusion devices. In this Letter, we present a theory for the dual cascade found in such plasmas, which predicts a range of new behavior that distinguishes this cascade from that of neutral fluid turbulence. These phenomena are explained in terms of the constrained nature of spectral transfer in nonlinear gyrokinetics. Accompanying this theory are the first observations of these phenomena, obtained via direct numerical simulations using the gyrokinetic code AstroGK. The basic mechanisms that are found provide a framework for understanding the turbulent energy transfer that couples scales both locally and nonlocally.
Hartouni, Edward; Eckart, Mark; Field, John; Grim, Gary; Hatarik, Robert; Moore, Alastair; Munro, David; Sayer, Daniel; Schlossberg, David
2017-10-01
Neutron kinetic energy distributions from fusion reactions are characterized predominantly by the excess energy, Q, of the fusion reaction and the variance of kinetic energy which is related to the thermal temperature of the plasma as shown by e.g. Brysk. High statistics, high quality neutron time-of-flight spectra obtained at the National Ignition Facility provide a means of measuring small changes to the neutron kinetic energy due to the spatial and temporal distribution of plasma temperature, density and velocity. The modifications to the neutron kinetic energy distribution as described by Munro include plasma velocity terms with spatial orientation, suggesting that the neutron kinetic energy distributions could be anisotropic when viewed by multiple lines-of-sight. These anisotropies provide a diagnostic of burn averaged plasma velocity distributions. We present the results of measurements made for a variety of DT implosions and discuss their possible physical interpretations. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC.
FLYWHEEL BASED KINETIC ENERGY RECOVERY SYSTEMS (KERS) INTEGRATED IN VEHICLES
THOMAS MATHEWS; NISHANTH D
2013-01-01
Today, many hybrid electric vehicles have been developed in order to reduce the consumption of fossil fuels; unfortunately these vehicles require electrochemical batteries to store energy, with high costs as well as poor conversion efficiencies. By integrating flywheel hybrid systems, these drawbacks can be overcome and can potentially replace battery powered hybrid vehicles cost effectively. The paper will explain the engineering, mechanics of the flywheel system and it’s working in detail. ...
An electrostatic storage ring for low kinetic energy electron collisions
Energy Technology Data Exchange (ETDEWEB)
Reddish, T J; Tessier, D R; Sullivan, M R; Thorn, P A [Department of Physics, University of Windsor, Windsor, N9B 3P4 (Canada); Hammond, P; Alderman, A J [School of Physics, CAMSP, University of Western Australia, Perth WA 6009 (Australia); Read, F H [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)
2009-11-01
The criteria are presented for stable multiple orbits of charged particles in a race-track shaped storage ring and applied to an electrostatic system consisting of two hemispherical deflector analyzers (HDA) connected by two separate sets of cylindrical lenses. The results of charged particle simulations and the formal matrix theory, including aberrations in the energy-dispersive electrostatic 'prisms', are in good agreement with the observed experimental operating conditions for this Electron Recycling Spectrometer (ERS).
Kinetic energy and added mass of hydrodynamically interacting gas bubbles in liquid
Kok, Jacobus B.W.
1988-01-01
By averaging the basic equations on microscale, expressions are derived for the effective added mass density and the kinetic energy density of a mixture of liquid and gas bubbles. Due to hydrodynamic interaction between the bubbles there appears to be a difference between the effective added mass
Evidence for cluster shape effects on the kinetic energy spectrum in thermionic emission.
Calvo, F; Lépine, F; Baguenard, B; Pagliarulo, F; Concina, B; Bordas, C; Parneix, P
2007-11-28
Experimental kinetic energy release distributions obtained for the thermionic emission from C(n) (-) clusters, 10theory, these different features are analyzed and interpreted as the consequence of contrasting shapes in the daughter clusters; linear and nonlinear isomers have clearly distinct signatures. These results provide a novel indirect structural probe for atomic clusters associated with their thermionic emission spectra.
Kinetic Energy from Supernova Feedback in High-resolution Galaxy Simulations
Simpson, Christine M.; Bryan, Greg L.; Hummels, Cameron; Ostriker, Jeremiah P.
2015-08-01
We describe a new method for adding a prescribed amount of kinetic energy to simulated gas modeled on a cartesian grid by directly altering grid cells’ mass and velocity in a distributed fashion. The method is explored in the context of supernova (SN) feedback in high-resolution (˜10 pc) hydrodynamic simulations of galaxy formation. Resolution dependence is a primary consideration in our application of the method, and simulations of isolated explosions (performed at different resolutions) motivate a resolution-dependent scaling for the injected fraction of kinetic energy that we apply in cosmological simulations of a 109 M⊙ dwarf halo. We find that in high-density media (≳50 cm-3) with coarse resolution (≳4 pc per cell), results are sensitive to the initial kinetic energy fraction due to early and rapid cooling. In our galaxy simulations, the deposition of small amounts of SN energy in kinetic form (as little as 1%) has a dramatic impact on the evolution of the system, resulting in an order-of-magnitude suppression of stellar mass. The overall behavior of the galaxy in the two highest resolution simulations we perform appears to converge. We discuss the resulting distribution of stellar metallicities, an observable sensitive to galactic wind properties, and find that while the new method demonstrates increased agreement with observed systems, significant discrepancies remain, likely due to simplistic assumptions that neglect contributions from SNe Ia and stellar winds.
Energy markets and price relations
International Nuclear Information System (INIS)
Bergendahl, P.A.
1986-10-01
The aim of the report is to elucidate the way and extent of the dependence of the price of different energy species of one another and particularly of crude oil prices. Oil, coal and natural gas can substitute each other at many applications. The prices are dependent on mining, processing and transporting. Forecasting of prices and future trends are discussed
Kinetic-energy matrix elements for atomic Hylleraas-CI wave functions
Energy Technology Data Exchange (ETDEWEB)
Harris, Frank E., E-mail: harris@qtp.ufl.edu [Department of Physics, University of Utah, Salt Lake City, Utah 84112, USA and Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, Florida 32611 (United States)
2016-05-28
Hylleraas-CI is a superposition-of-configurations method in which each configuration is constructed from a Slater-type orbital (STO) product to which is appended (linearly) at most one interelectron distance r{sub ij}. Computations of the kinetic energy for atoms by this method have been difficult due to the lack of formulas expressing these matrix elements for general angular momentum in terms of overlap and potential-energy integrals. It is shown here that a strategic application of angular-momentum theory, including the use of vector spherical harmonics, enables the reduction of all atomic kinetic-energy integrals to overlap and potential-energy matrix elements. The new formulas are validated by showing that they yield correct results for a large number of integrals published by other investigators.
Directory of Open Access Journals (Sweden)
Tong Wen
Full Text Available The microwave-assisted leaching was a new approach to intensify the copper recovery from chalcopyrite by hydrometallurgy. In this work, the effect of microwave-assisted heating on chalcopyrite leaching of kinetics, interfacial reaction temperature and surface energy were investigated. The activation energy of chalcopyrite leaching was affected indistinctively by the microwave-assisted heating (39.1 kJ/mol compared with the conventional heating (43.9 kJ/mol. However, the boiling point of the leaching system increased through microwave-assisted heating. Because of the improved boiling point and the selective heating of microwave, the interfacial reaction temperature increased significantly, which gave rise to the increase of the leaching recovery of copper. Moreover, the surface energy of the chalcopyrite through microwave-assisted heating was also enhanced, which was beneficial to strengthen the leaching of chalcopyrite. Keywords: Microwave-assisted heating, Chalcopyrite, Leaching kinetics, Interface temperature, Surface energy
Konop, Katherine A; Strifling, Kelly M B; Wang, Mei; Cao, Kevin; Eastwood, Daniel; Jackson, Scott; Ackman, Jeffrey; Altiok, Haluk; Schwab, Jeffrey; Harris, Gerald F
2009-01-01
We evaluated the relationships between upper extremity (UE) kinetics and the energy expenditure index during anterior and posterior walker-assisted gait in children with spastic diplegic cerebral palsy (CP). Ten children (3 boys, 7 girls; mean age 12.1 years; range 8 to 18 years) with spastic diplegic CP, who ambulated with a walker underwent gait analyses that included UE kinematics and kinetics. Upper extremity kinetics were obtained using instrumented walker handles. Energy expenditure index was obtained using the heart rate method (EEIHR) by subtracting resting heart rate from walking heart rate, and dividing by the walking speed. Correlations were sought between the kinetic variables and the EEIHR and temporal and stride parameters. In general, anterior walker use was associated with a higher EEIHR. Several kinetic variables correlated well with temporal and stride parameters, as well as the EEIHR. All of the significant correlations (r>0.80; pwalker use and involved joint reaction forces (JRF) rather than moments. Some variables showed multiple strong correlations during anterior walker use, including the medial JRF in the wrist, the posterior JRF in the elbow, and the inferior and superior JRFs in the shoulder. The observed correlations may indicate a relationship between the force used to advance the body forward within the walker frame and an increased EEIHR. More work is needed to refine the correlations, and to explore relationships with other variables, including the joint kinematics.
Frustrated Kinetic Energy, the Optical Sum Rule, and the Mechanism of Superconductivity
International Nuclear Information System (INIS)
Chakravarty, S.; Kee, H.; Abrahams, E.
1999-01-01
The basis of the interlayer tunneling theory of high-temperature superconductivity is that the electronic kinetic energy in a direction perpendicular to the copper-oxygen planes is a substantial fraction of the condensation energy. This issue is critically examined, and it is argued from a rigorous conductivity sum rule that the consequences of this theory are consistent with recent optical and penetration depth measurements. copyright 1999 The American Physical Society
The Control Based on Internal Average Kinetic Energy in Complex Environment for Multi-robot System
Yang, Mao; Tian, Yantao; Yin, Xianghua
In this paper, reference trajectory is designed according to minimum energy consumed for multi-robot system, which nonlinear programming and cubic spline interpolation are adopted. The control strategy is composed of two levels, which lower-level is simple PD control and the upper-level is based on the internal average kinetic energy for multi-robot system in the complex environment with velocity damping. Simulation tests verify the effectiveness of this control strategy.
Turbulent kinetic energy spectrum in very anisothermal flows
International Nuclear Information System (INIS)
Serra, Sylvain; Toutant, Adrien; Bataille, Françoise; Zhou, Ye
2012-01-01
In this Letter, we find that the Kolmogorov scaling law is no longer valid when the flow is submitted to strong dilatational effects caused by high temperature gradients. As a result, in addition to the nonlinear time scale, there is a much shorter “temperature gradients” time scale. We propose a model that estimates the time scale of the triple decorrelation incorporating the influences of the temperature gradient. The model agrees with the results from the thermal large-eddy simulations of different Reynolds numbers and temperature gradients. This Letter provides a better understanding of the very anisothermal turbulent flow. -- Highlights: ► Turbulent flows subject to high temperature gradients are considered. ► The new “temperature gradients” time scale is determined. ► A generalized energy spectrum is developed to incorporate the effects of temperature gradient.
Lifetime and kinetic energy release of metastable dications dissociation
International Nuclear Information System (INIS)
Alagia, M.; Candori, P.; Falcinelli, S.; Mundim, K.C.; Mundim, M.S.P.; Pirani, F.; Richter, R.; Stranges, S.; Vecchiocattivi, F.
2012-01-01
Graphical abstract: A statistical method is proposed for extracting dynamics information from coincidence data in double photoionization of molecules. Highlights: ► When a photon, with sufficient energy, hits a molecule, a doubly charged ion can be formed. This dication has often a large probability of dissociate in two positive singly charged ions. ► Experiments of photoelectron–photoion–photoion coincidence can provide valuable information about the dynamics of such dissociation processes. ► A statistical method is proposed for extracting such information from the coincidence data. - Abstract: A new method for the determination of dynamical features of the molecular dication dissociation processes, following the single photon double ionization, investigated by time-of-flight mass spectrometry technique has been developed. The method is based on an extension of the generalized simulated annealing statistical methodology, previously applied in other fields. Here it is described and applied, as an example, to the case of the dissociation of the CO 2 2+ dication giving CO + + O + ion fragments. The results are consistent with previous determination of the metastable lifetime of the dication, but the analysis also provides additional information about the dynamics of the reaction.
Hot Brakes and Energy-Related Concepts: Is Energy Lost?
Lopez, V.; Pinto, R.
2012-01-01
This paper describes a secondary school experience which is intended to help students to think profoundly about some energy-related concepts. It is quite different to other experiences of mechanics because the focus is not on the quantitative calculation of energy conservation but on the qualitative understanding of energy degradation. We first…
Energy conditions and stability in general relativity
International Nuclear Information System (INIS)
Hall, G.S.
1982-01-01
The dominant energy condition in general relativity theory, which says that every observer measures a nonnegative local energy density and a nonspacelike local energy flow, is examined in connection with the types of energy-momentum tensor it permits. The condition that the energy-momentum tensor be ''stable'' in obeying the dominant energy conditions is then defined in terms of a suitable topology on the set of energy-momentum tensors on space-time and the consequences are evaluated and discussed. (author)
International Nuclear Information System (INIS)
Ohya, Kaoru; Kawata, Jun; Mori, Ichiro
1989-01-01
Incident angle dependence of kinetic secondary electron emission from metals resulting from incidence of keV ions is investigated by computer simulation with the TRIM Monte Carlo program of ion scattering in matter. The results show large deviations from the inverse cosine dependence, which derives from high-energy approximation, because of a series of elastic collisions of incident ions with metal atoms. In the keV energy region, the elastic collisions have two different effects on the angular dependence for relatively high-energy light ions and for low-energy heavy ions: they result in over- and under-inverse-cosine dependences, respectively. The properties are observed even with an experiment of the keV-neutral incidence on a contaminated surface. In addition, the effects of the thin oxide layer and roughness on the surface are examined with simplified models. (author)
Energy Technology Data Exchange (ETDEWEB)
Plasencia Rodriguez, J. P.
2003-07-01
The R. O. Kinetic is a novel system of energy saving, for desalination plants by reverse osmosis, based on the isobaric chambers. With this system it is able to obtain values of specific consumption of energy during the process, around 2, 1-2,2 kWh/m''3, reducing the operation cost of these facilities. (Author)
Pomorski, K.; Nerlo-Pomorska, B.; Bartel, J.; Schmitt, C.
2018-03-01
The fission-fragment mass and total kinetic energy (TKE) distributions are evaluated in a quantum mechanical framework using elongation, mass asymmetry, neck degree of freedom as the relevant collective parameters in the Fourier shape parametrization recently developed by us. The potential energy surfaces (PES) are calculated within the macroscopic-microscopic model based on the Lublin-Strasbourg Drop (LSD), the Yukawa-folded (YF) single-particle potential and a monopole pairing force. The PES are presented and analysed in detail for even-even Plutonium isotopes with A = 236-246. They reveal deep asymmetric valleys. The fission-fragment mass and TKE distributions are obtained from the ground state of a collective Hamiltonian computed within the Born-Oppenheimer approximation, in the WKB approach by introducing a neck-dependent fission probability. The calculated mass and total kinetic energy distributions are found in good agreement with the data.
Distributed activation energy model for kinetic analysis of multi-stage hydropyrolysis of coal
Energy Technology Data Exchange (ETDEWEB)
Liu, X.; Li, W.; Wang, N.; Li, B. [Chinese Academy of Sciences, Taiyuan (China). Inst. of Coal Chemistry
2003-07-01
Based on the new analysis of distributed activation energy model, a bicentral distribution model was introduced to the analysis of multi-stage hydropyrolysis of coal. The hydropyrolysis for linear temperature programming with and without holding stage were mathematically described and the corresponding kinetic expressions were achieved. Based on the kinetics, the hydropyrolysis (HyPr) and multi-stage hydropyrolysis (MHyPr) of Xundian brown coal was simulated. The results shows that both Mo catalyst and 2-stage holding can lower the apparent activation energy of hydropyrolysis and make activation energy distribution become narrow. Besides, there exists an optimum Mo loading of 0.2% for HyPy of Xundian lignite. 10 refs.
Photodissociation dynamics of propene at 157.6 nm: Kinetic energy distributions and branching ratios
International Nuclear Information System (INIS)
Lee, S.-H.; Lee, Y.-Y.; Lee, Yuan T.; Yang Xueming
2003-01-01
Photodissociation dynamics of propene at 157.6 nm has been investigated in a molecular beam apparatus using the photofragment translational spectroscopic technique combined with the vacuum ultraviolet ionization method. Eleven photofragments have been successfully detected and ascribed to eight (five binary and three triple) dissociation channels: namely, C 3 H 5 +H, C 3 H 4 +H+H, C 3 H 4 +H 2 , C 3 H 3 +H 2 +H, C 2 H 4 +CH 2 , C 2 H 3 +CH 3 , C 2 H 2 +CH 4 , and C 2 H 2 +CH 3 +H. Their branching ratios have been determined to be 1%, 7%, 2 H 2 +CH 3 +H channel. In addition, the averaged kinetic energy releases and the fractions in translational energy have also been determined from the measured kinetic energy distributions. For the binary dissociation channels, the fractions in translational energy are less than 18% except the C 3 H 5 +H channel, whereas they are more than 42% for the triple dissociation channels. An intriguing finding indicates that the C 2 H 4 +CH 2 channel has a nearly identical kinetic energy distribution and a similar branching ratio to the C 2 H 3 +CH 3 channel, although the former undergoes a three-center elimination process different from the C-C bond rupture occurring in the latter
Statistical properties of kinetic and total energy densities in reverberant spaces
DEFF Research Database (Denmark)
Jacobsen, Finn; Molares, Alfonso Rodriguez
2010-01-01
Many acoustical measurements, e.g., measurement of sound power and transmission loss, rely on determining the total sound energy in a reverberation room. The total energy is usually approximated by measuring the mean-square pressure (i.e., the potential energy density) at a number of discrete....... With the advent of a three-dimensional particle velocity transducer, it has become somewhat easier to measure total rather than only potential energy density in a sound field. This paper examines the ensemble statistics of kinetic and total sound energy densities in reverberant enclosures theoretically...... positions. The idea of measuring the total energy density instead of the potential energy density on the assumption that the former quantity varies less with position than the latter goes back to the 1930s. However, the phenomenon was not analyzed until the late 1970s and then only for the region of high...
Statistical model of a flexible inextensible polymer chain: The effect of kinetic energy
Pergamenshchik, V. M.; Vozniak, A. B.
2017-01-01
Because of the holonomic constraints, the kinetic energy contribution in the partition function of an inextensible polymer chain is difficult to find, and it has been systematically ignored. We present the first thermodynamic calculation incorporating the kinetic energy of an inextensible polymer chain with the bending energy. To explore the effect of the translation-rotation degrees of freedom, we propose and solve a statistical model of a fully flexible chain of N +1 linked beads which, in the limit of smooth bending, is equivalent to the well-known wormlike chain model. The partition function with the kinetic and bending energies and correlations between orientations of any pair of links and velocities of any pair of beads are found. This solution is precise in the limits of small and large rigidity-to-temperature ratio b /T . The last exact solution is essential as even very "harmless" approximation results in loss of the important effects when the chain is very rigid. For very high b /T , the orientations of different links become fully correlated. Nevertheless, the chain does not go over into a hard rod even in the limit b /T →∞ : While the velocity correlation length diverges, the correlations themselves remain weak and tend to the value ∝T /(N +1 ). The N dependence of the partition function is essentially determined by the kinetic energy contribution. We demonstrate that to obtain the correct energy and entropy in a constrained system, the T derivative of the partition function has to be applied before integration over the constraint-setting variable.
Kinetic energy recovery turbine technology: resource assessment and site development strategy
Energy Technology Data Exchange (ETDEWEB)
Briand, Marie-Helene; Ng, Karen
2010-09-15
New technologies to extract readily available energy from waves, tides and river flow are being developed and are promising but are still at the demonstration stage. Harnessing kinetic energy from currents (hydrokinetic power) is considered an attractive and cost-effective renewable energy solution to replace thermal generation without requiring construction of a dam or large civil works. The nature of this innovative hydrokinetic technology requires an adaptation of conventional approach to project engineering and environmental impact studies. This paper presents the approach developed by RSW to design a hydrokinetic site in the riverine environment, from resource assessment to detailed engineering design.
Wang, Y Y; Grygiel, C; Dufour, C; Sun, J R; Wang, Z G; Zhao, Y T; Xiao, G Q; Cheng, R; Zhou, X M; Ren, J R; Liu, S D; Lei, Y; Sun, Y B; Ritter, R; Gruber, E; Cassimi, A; Monnet, I; Bouffard, S; Aumayr, F; Toulemonde, M
2014-07-18
Modification of surface and bulk properties of solids by irradiation with ion beams is a widely used technique with many applications in material science. In this study, we show that nano-hillocks on CaF2 crystal surfaces can be formed by individual impact of medium energy (3 and 5 MeV) highly charged ions (Xe(22+) to Xe(30+)) as well as swift (kinetic energies between 12 and 58 MeV) heavy xenon ions. For very slow highly charged ions the appearance of hillocks is known to be linked to a threshold in potential energy (Ep) while for swift heavy ions a minimum electronic energy loss per unit length (Se) is necessary. With our results we bridge the gap between these two extreme cases and demonstrate, that with increasing energy deposition via Se the Ep-threshold for hillock production can be lowered substantially. Surprisingly, both mechanisms of energy deposition in the target surface seem to contribute in an additive way, which can be visualized in a phase diagram. We show that the inelastic thermal spike model, originally developed to describe such material modifications for swift heavy ions, can be extended to the case where both kinetic and potential energies are deposited into the surface.
Energy problem and harmony in international relations
International Nuclear Information System (INIS)
Ogata, Akira
1975-01-01
Energy problems and harmony in international relation are closely related with world politics. Oil is destined to remain as the primary energy source for the time being. The situation of oil has different implications to the U.S. and U.S.S.R., oil producing countries, and consumer countries. The hasty attitude in the past to attain energy sufficiency must be avoided by all means. Congenial harmony is to be established in international relation to meet world energy requirement. This also applies to the case of nuclear power in future. (Mori, K.)
On the ultrafast kinetics of the energy and electron transfer reactions in photosystem I
Energy Technology Data Exchange (ETDEWEB)
Slavov, Chavdar Lyubomirov
2009-07-09
The subject of the current work is one of the main participants in the light-dependent phase of oxygenic photosynthesis, Photosystem I (PS I). This complex carries an immense number of cofactors: chlorophylls (Chl), carotenoids, quinones, etc, which together with the protein entity exhibit several exceptional properties. First, PS I has an ultrafast light energy trapping kinetics with a nearly 100% quantum efficiency. Secondly, both of the electron transfer branches in the reaction center are suggested to be active. Thirdly, there are some so called 'red' Chls in the antenna system of PS I, absorbing light with longer wavelengths than the reaction center. These 'red' Chls significantly modify the trapping kinetics of PS I. The purpose of this thesis is to obtain better understanding of the above-mentioned, specific features of PS I. This will not merely cast more light on the mechanisms of energy and electron transfer in the complex, but also will contribute to the future developments of optimized artificial light-harvesting systems. In the current work, a number of PS I complexes isolated from different organisms (Thermosynechococcus elongatus, Chlamydomonas reinhardtii, Arabidopsis thaliana) and possessing distinctive features (different macroorganisation, monomers, trimers, monomers with a semibelt of peripheral antenna attached; presence of 'red' Chls) is investigated. The studies are primarily focused on the electron transfer kinetics in each of the cofactor branches in the PS I reaction center, as well as on the effect of the antenna size and the presence of 'red' Chls on the trapping kinetics of PS I. These aspects are explored with the help of several ultrafast optical spectroscopy methods: (i) time-resolved fluorescence ? single photon counting and synchroscan streak camera; and (ii) ultrafast transient absorption. Physically meaningful information about the molecular mechanisms of the energy trapping in PS I is
A fluctuation relation for the probability of energy backscatter
Vela-Martin, Alberto; Jimenez, Javier
2017-11-01
We simulate the large scales of an inviscid turbulent flow in a triply periodic box using a dynamic Smagorinsky model for the sub-grid stresses. The flow, which is forced to constant kinetic energy, is fully reversible and can develop a sustained inverse energy cascade. However, due to the large number of degrees freedom, the probability of spontaneous mean inverse energy flux is negligible. In order to quantify the probability of inverse energy cascades, we test a local fluctuation relation of the form log P(A) = - c(V , t) A , where P(A) = p(| Cs|V,t = A) / p(| Cs|V , t = - A) , p is probability, and | Cs|V,t is the average of the least-squared dynamic model coefficient over volume V and time t. This is confirmed when Cs is averaged over sufficiently large domains and long times, and c is found to depend linearly on V and t. In the limit in which V 1 / 3 is of the order of the integral scale and t is of the order of the eddy-turnover time, we recover a global fluctuation relation that predicts a negligible probability of a sustained inverse energy cascade. For smaller V and t, the local fluctuation relation provides useful predictions on the occurrence of local energy backscatter. Funded by the ERC COTURB project.
Ion kinetic energy distribution in a pulsed vacuum arc with a straight magnetic filter
International Nuclear Information System (INIS)
Giuliani, L; Grondona, D; Kelly, H; Minotti, F
2008-01-01
In vacuum arcs of interest for film deposition the ion kinetic energy is of importance because it influences the coating properties. In this kind of discharge, the ions come out from the cathode spots with a high kinetic energy (20-150 eV). In the present work, we present measurements of vacuum arc ion energy distributions in a pulsed vacuum arc with a straight magnetic filter. A retarding field analyser (RFA) was used to perform the measurements that were carried out with a variable magnetic field strength (of the order of 10 mT). Since the interpretation of the results obtained from the RFA lies in the knowledge of the plasma and floating potential values, we have employed also Langmuir probes for determining those quantities. The obtained results for the ion kinetic energy are similar to those reported by other authors, but they were also found to be independent of the magnetic field strength. The electron temperature was also found to be independent of the magnetic field strength and of the axial position along the filter, indicating the absence of collisions.
Relating Financial and Energy Return on Investment
Directory of Open Access Journals (Sweden)
Carey W. King
2011-10-01
Full Text Available For many reasons, including environmental impacts and the peaking and depletion of the highest grades of fossil energy, it is very important to have sound methods for the evaluation of energy technologies and the profitability of the businesses that utilize them. In this paper we derive relations among the biophysical characteristic of an energy resource in relation to the businesses and technologies that exploit them. These relations include the energy return on energy investment (EROI, the price of energy, and the profit of an energy business. Our analyses show that EROI and the price of energy are inherently inversely related such that as EROI decreases for depleting fossil fuel production, the corresponding energy prices increase dramatically. Using energy and financial data for the oil and gas production sector, we demonstrate that the equations sufficiently describe the fundamental trends between profit, price, and EROI. For example, in 2002 an EROI of 11:1 for US oil and gas translates to an oil price of 24 $2005/barrel at a typical profit of 10%. This work sets the stage for proper EROI and price comparisons of individual fossil and renewable energy businesses as well as the electricity sector as a whole. Additionally, it presents a framework for incorporating EROI into larger economic systems models.
Khoma, Mykhaylo; Jaquet, Ralph
2017-09-21
The kinetic energy operator for triatomic molecules with coordinate or distance-dependent nuclear masses has been derived. By combination of the chain rule method and the analysis of infinitesimal variations of molecular coordinates, a simple and general technique for the construction of the kinetic energy operator has been proposed. The asymptotic properties of the Hamiltonian have been investigated with respect to the ratio of the electron and proton mass. We have demonstrated that an ad hoc introduction of distance (and direction) dependent nuclear masses in Cartesian coordinates preserves the total rotational invariance of the problem. With the help of Wigner rotation functions, an effective Hamiltonian for nuclear motion can be derived. In the derivation, we have focused on the effective trinuclear Hamiltonian. All necessary matrix elements are given in closed analytical form. Preliminary results for the influence of non-adiabaticity on vibrational band origins are presented for H 3 + .
Budget of Turbulent Kinetic Energy in a Shock Wave Boundary-Layer Interaction
Vyas, Manan A.; Waindim, Mbu; Gaitonde, Datta V.
2016-01-01
Implicit large-eddy simulation (ILES) of a shock wave/boundary-layer interaction (SBLI) was performed. Quantities present in the exact equation of the turbulent kinetic energy transport were accumulated and used to calculate terms like production, dissipation, molecular diffusion, and turbulent transport. The present results for a turbulent boundary layer were validated by comparison with direct numerical simulation data. It was found that a longer development domain was necessary for the boundary layer to reach an equilibrium state and a finer mesh resolution would improve the predictions. In spite of these findings, trends of the present budget match closely with that of the direct numerical simulation. Budgets for the SBLI region are presented at key axial stations. These budgets showed interesting dynamics as the incoming boundary layer transforms and the terms of the turbulent kinetic energy budget change behavior within the interaction region.
Wave-particle energy exchange directly observed in a kinetic Alfvén-branch wave.
Gershman, Daniel J; F-Viñas, Adolfo; Dorelli, John C; Boardsen, Scott A; Avanov, Levon A; Bellan, Paul M; Schwartz, Steven J; Lavraud, Benoit; Coffey, Victoria N; Chandler, Michael O; Saito, Yoshifumi; Paterson, William R; Fuselier, Stephen A; Ergun, Robert E; Strangeway, Robert J; Russell, Christopher T; Giles, Barbara L; Pollock, Craig J; Torbert, Roy B; Burch, James L
2017-03-31
Alfvén waves are fundamental plasma wave modes that permeate the universe. At small kinetic scales, they provide a critical mechanism for the transfer of energy between electromagnetic fields and charged particles. These waves are important not only in planetary magnetospheres, heliospheres and astrophysical systems but also in laboratory plasma experiments and fusion reactors. Through measurement of charged particles and electromagnetic fields with NASA's Magnetospheric Multiscale (MMS) mission, we utilize Earth's magnetosphere as a plasma physics laboratory. Here we confirm the conservative energy exchange between the electromagnetic field fluctuations and the charged particles that comprise an undamped kinetic Alfvén wave. Electrons confined between adjacent wave peaks may have contributed to saturation of damping effects via nonlinear particle trapping. The investigation of these detailed wave dynamics has been unexplored territory in experimental plasma physics and is only recently enabled by high-resolution MMS observations.
Wave-Particle Energy Exchange Directly Observed in a Kinetic Alfven-Branch Wave
Gershman, Daniel J.; F-Vinas, Adolfo; Dorelli, John C.; Boardsen, Scott A. (Inventor); Avanov, Levon A.; Bellan, Paul M.; Schwartz, Steven J.; Lavraud, Benoit; Coffey, Victoria N.; Chandler, Michael O.;
2017-01-01
Alfven waves are fundamental plasma wave modes that permeate the universe. At small kinetic scales they provide a critical mechanism for the transfer of energy between electromagnetic fields and charged particles. These waves are important not only in planetary magnetospheres, heliospheres, and astrophysical systems, but also in laboratory plasma experiments and fusion reactors. Through measurement of charged particles and electromagnetic fields with NASAs Magnetospheric Multiscale (MMS) mission, we utilize Earths magnetosphere as a plasma physics laboratory. Here we confirm the conservative energy exchange between the electromagnetic field fluctuations and the charged particles that comprise an undamped kinetic Alfven wave. Electrons confined between adjacent wave peaks may have contributed to saturation of damping effects via non-linear particle trapping. The investigation of these detailed wave dynamics has been unexplored territory in experimental plasma physics and is only recently enabled by high-resolution MMS observations.
Kinetic energy and scalar spectra in high Rayleigh number axially homogeneous buoyancy driven turbulence
Pawar, Shashikant S.; Arakeri, Jaywant H.
2016-06-01
Kinetic energy and scalar spectra from the measurements in high Rayleigh number axially homogeneous buoyancy driven turbulent flow are presented. Kinetic energy and concentration (scalar) spectra are obtained from the experiments wherein density difference is created using brine and fresh water and temperature spectra are obtained from the experiments in which heat is used. Scaling of the frequency spectra of lateral and longitudinal velocity near the tube axis is closer to the Kolmogorov-Obukhov scaling, while the scalar spectra show some evidence of dual scaling, Bolgiano-Obukhov scaling followed by Obukhov-Corrsin scaling. These scalings are also observed in the corresponding second order spatial structure functions of velocity and concentration fluctuations.
Improving the signal-to-noise ratio in mass and ion kinetic energy spectrometers
International Nuclear Information System (INIS)
Brenton, A.G.; Beynon, J.H.; Morgan, R.P.
1979-01-01
The signal-to-noise ratio in mass and ion kinetic energy spectrometers is limited by noise generated from the presence of scattered ions and neutrals. Methods of eliminating this are illustrated with reference to the ZAB-2F instrument manufactured by VG-Micromass Ltd. It is estimated that after the modifications the instrument is capable, on a routine basis, of measuring peaks corresponding to the arrival of ions at a rate of the order of 1 ion s -1 . (Auth.)
Electron screening and kinetic-energy oscillations in a strongly coupled plasma
International Nuclear Information System (INIS)
Chen, Y.C.; Simien, C.E.; Laha, S.; Gupta, P.; Martinez, Y.N.; Mickelson, P.G.; Nagel, S.B.; Killian, T.C.
2004-01-01
We study equilibration of strongly coupled ions in an ultracold neutral plasma produced by photoionizing laser-cooled and trapped atoms. By varying the electron temperature, we show that electron screening modifies the equilibrium ion temperature. Even with few electrons in a Debye sphere, the screening is well described by a model using a Yukawa ion-ion potential. We also observe damped oscillations of the ion kinetic energy that are a unique feature of equilibration of a strongly coupled plasma
Zou, Jiaxiu; Peng, Xiaolan; Li, Miao; Xiong, Ying; Wang, Bing; Dong, Faqin; Wang, Bin
2017-03-01
In the present study, the electrochemical oxidation of real wastewaters discharged by textile industry was carried out using a boron-doped diamond (BDD) anode. The effect of operational variables, such as applied current density (20-100 mA·cm -2 ), NaCl concentration added to the real wastewaters (0-3 g·L -1 ), and pH value (2.0-10.0), on the kinetics of COD oxidation and on the energy consumption was carefully investigated. The obtained experimental results could be well matched with a proposed kinetic model, in which the indirect oxidation mediated by electrogenerated strong oxidants would be described through a pseudo-first-order kinetic constant k. Values of k exhibited a linear increase with increasing applied current density and decreasing pH value, and an exponential increase with NaCl concentration. Furthermore, high oxidation kinetics resulted in low specific energy consumption, but this conclusion was not suitable to the results obtained under different applied current density. Under the optimum operational conditions, it only took 3 h to complete remove the COD in the real textile wastewaters and the specific energy consumption could be as low as 11.12 kWh·kg -1 COD. The obtained results, low energy consumption and short electrolysis time, allowed to conclude that the electrochemical oxidation based on BDD anodes would have practical industrial application for the treatment of real textile wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.
Gould, Ian R; Wosinska, Zofia M; Farid, Samir
2006-01-01
Accurate oxidation potentials for organic compounds are critical for the evaluation of thermodynamic and kinetic properties of their radical cations. Except when using a specialized apparatus, electrochemical oxidation of molecules with reactive radical cations is usually an irreversible process, providing peak potentials, E(p), rather than thermodynamically meaningful oxidation potentials, E(ox). In a previous study on amines with radical cations that underwent rapid decarboxylation, we estimated E(ox) by correcting the E(p) from cyclic voltammetry with rate constants for decarboxylation obtained using laser flash photolysis. Here we use redox equilibration experiments to determine accurate relative oxidation potentials for the same amines. We also describe an extension of these experiments to show how relative oxidation potentials can be obtained in the absence of equilibrium, from a complete kinetic analysis of the reversible redox kinetics. The results provide support for the previous cyclic voltammetry/laser flash photolysis method for determining oxidation potentials.
Fathali, M.; Deshiri, M. Khoshnami
2016-04-01
The shearless mixing layer is generated from the interaction of two homogeneous isotropic turbulence (HIT) fields with different integral scales ℓ1 and ℓ2 and different turbulent kinetic energies E1 and E2. In this study, the sensitivity of temporal evolutions of two-dimensional, incompressible shearless mixing layers to the parametric variations of ℓ1/ℓ2 and E1/E2 is investigated. The sensitivity methodology is based on the nonintrusive approach; using direct numerical simulation and generalized polynomial chaos expansion. The analysis is carried out at Reℓ 1=90 for the high-energy HIT region and different integral length scale ratios 1 /4 ≤ℓ1/ℓ2≤4 and turbulent kinetic energy ratios 1 ≤E1/E2≤30 . It is found that the most influential parameter on the variability of the mixing layer evolution is the turbulent kinetic energy while variations of the integral length scale show a negligible influence on the flow field variability. A significant level of anisotropy and intermittency is observed in both large and small scales. In particular, it is found that large scales have higher levels of intermittency and sensitivity to the variations of ℓ1/ℓ2 and E1/E2 compared to the small scales. Reconstructed response surfaces of the flow field intermittency and the turbulent penetration depth show monotonic dependence on ℓ1/ℓ2 and E1/E2 . The mixing layer growth rate and the mixing efficiency both show sensitive dependence on the initial condition parameters. However, the probability density function of these quantities shows relatively small solution variations in response to the variations of the initial condition parameters.
Measuring kinetic energy changes in the mesoscale with low acquisition rates
Energy Technology Data Exchange (ETDEWEB)
Roldán, É. [ICFO–Institut de Ciències Fotòniques, Mediterranean Technology Park, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona) (Spain); GISC–Grupo Interdisciplinar de Sistemas Complejos, Madrid (Spain); Martínez, I. A.; Rica, R. A., E-mail: rul@ugr.es [ICFO–Institut de Ciències Fotòniques, Mediterranean Technology Park, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona) (Spain); Dinis, L. [GISC–Grupo Interdisciplinar de Sistemas Complejos, Madrid (Spain); Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, 28040 Madrid (Spain)
2014-06-09
We report on the measurement of the average kinetic energy changes in isothermal and non-isothermal quasistatic processes in the mesoscale, realized with a Brownian particle trapped with optical tweezers. Our estimation of the kinetic energy change allows to access to the full energetic description of the Brownian particle. Kinetic energy estimates are obtained from measurements of the mean square velocity of the trapped bead sampled at frequencies several orders of magnitude smaller than the momentum relaxation frequency. The velocity is tuned applying a noisy electric field that modulates the amplitude of the fluctuations of the position and velocity of the Brownian particle, whose motion is equivalent to that of a particle in a higher temperature reservoir. Additionally, we show that the dependence of the variance of the time-averaged velocity on the sampling frequency can be used to quantify properties of the electrophoretic mobility of a charged colloid. Our method could be applied to detect temperature gradients in inhomogeneous media and to characterize the complete thermodynamics of biological motors and of artificial micro and nanoscopic heat engines.
Recruiting at the Edge: Kinetic Energy Inhibits Anchovy Populations in the Western Mediterranean
Ruiz, Javier; Macías, Diego; Rincón, Margarita M.; Pascual, Ananda; Catalán, Ignacio A.; Navarro, Gabriel
2013-01-01
The Strait of Gibraltar replenishes the Mediterranean with Atlantic waters through an intense eastward current known as the Atlantic Jet (AJ). The AJ fertilizes the southwestern Mediterranean and is considered to be the ultimate factor responsible for the comparatively high fish production of this region. Here, we perform an analysis of the available historical catches and catch per unit effort (CPUE), together with a long series of surface currents, kinetic energy and chlorophyll concentration. We show that the high kinetic energy of the AJ increases primary production but also negatively impacts the recruitment of anchovy. We contend that anchovy recruitment in the region is inhibited by the advection and dispersion of larvae and post-larvae during periods of strong advection by the AJ. The inhibitory impact of kinetic energy on anchovy landings is not a transient but rather a persistent state of the system. An exceptional combination of events creates an outbreak of this species in the Alboran Sea. These events depend on the Mediterranean-Atlantic exchange of water masses and, therefore, are highly sensitive to climate changes that are projected, though not always negatively, for fish landings. PMID:23451027
Nucleation of diindenoperylene and pentacene at thermal and hyperthermal incident kinetic energies
Energy Technology Data Exchange (ETDEWEB)
Kish, Edward R.; Desai, Tushar V.; Greer, Douglas R.; Engstrom, James R., E-mail: jre7@cornell.edu [School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853 (United States); Woll, Arthur R. [Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York 14853 (United States)
2015-05-15
The authors have examined the nucleation of diindenoperylene (DIP) on SiO{sub 2} employing primarily atomic force microscopy and focusing on the effect of incident kinetic energy employing both thermal and supersonic sources. For all incident kinetic energies examined (E{sub i} = 0.09–11.3 eV), the nucleation of DIP is homogeneous and the dependence of the maximum island density on the growth rate is described by a power law. A critical nucleus of approximately two molecules is implicated by our data. A re-examination of the nucleation of pentacene on SiO{sub 2} gives the same major result that the maximum island density is determined by the growth rate, and it is independent of the incident kinetic energy. These observations are readily understood by factoring in the size of the critical nucleus in each case, and the island density, which indicates that diffusive transport of molecules to the growing islands dominate the dynamics of growth in the submonolayer regime.
Kinetics of interaction from low-energy-ion bombardment of surfaces
International Nuclear Information System (INIS)
Horton, C.C.
1988-01-01
The kinetics of interaction from low energy oxygen ion bombardment of carbon and Teflon surfaces have been investigated. The surfaces were bombarded with 4.5 to 93 eV oxygen ions and emitted species were observed with a mass spectrometer. To obtain the kinetic information, the ion beam was square pulse modulated and reaction products were observed as a function of time. The kinetic information is contained in the response of the emitted species to the pulsed ion beam. Oxygen bombardment of carbon produced CO in three parallel branches with each following an adsorption-desorption process. The fast branch, with a rate constants of 12,000/sec, appeared to be sputter induced an was absent below about 19 eV. The medium and slow branches, with rate constants of 850/sec and 45/sec respectively, has little energy dependence and appeared to be due to chemical sputtering from two sites. The ratio of the fraction of the medium branch to that of the slow was constant at 1:3. The bombardment of Teflon produced CF in two parallel branches, with one following a series process and the other an adsorb-desorb process. The rate constant of the other branch were 22,000/sec and 7,000/sec and the rate constant of the other branch was 90/sec. The total signal fell monotonically with decreasing ion energy with the fraction for each branch holding constant at 71% for the series and 29% for the adsorb-desorb
Translational kinetic energy induced oxidation on Ti(0001) surfaces using a supersonic O2 beam
International Nuclear Information System (INIS)
Ogawa, Shuichi; Takakuwa, Yuji; Ishidzuka, Shinji; Yoshigoe, Akitaka; Teraoka, Yuden; Moritani, Kousuke; Mizuno, Yoshiyuki
2007-01-01
The initial sticking probability S 0 of O 2 molecules on a Ti(0001)1x1 surface at room temperature was measured as a function of translational kinetic energy E t by real-time photoelectron spectroscopy. The O 1s photoelectron spectra can be fitted well with three components A, B and C, where the chemical shift of component B and C are +0.7 and +1.6 eV relative to the binding energy of component A (528.8 eV). Upon exposing to the O 2 beam, component A and C appear dominantly and component B grows with an incubation time, indicating that two kinds of chemical adsorption states are concerned with dissociative adsorption of O 2 molecules at the initial stage. The E t dependences of S 0 show quite different behaviors between component A and C: S 0 of component C decreases monotonously with E t and is almost constant above 0.6 eV, while S 0 of component A shows a rapid decrease followed by a gradual increase with a minimum at ∼0.5 eV and then decreases two small maxima at ∼0.9 and ∼1.8 eV. The observed E t dependences of S 0 for component A and C are discussed in terms of a trapping-mediated adsorption and an activated adsorption process and the chemical adsorption state corresponding to component A and C is also considered. (author)
International Nuclear Information System (INIS)
Montoya, M.; Rojas, J.; Saettone, E.
2007-01-01
The mass and kinetic energy distribution of nuclear fragments from the thermal neutron-induced fission of 235 U have been studied using a Monte Carlo simulation. Besides reproducing the pronounced broadening on the standard deviation of the final fragment kinetic energy distribution (σ e (m)) around the mass number m = 109, our simulation also produces a second broadening around m = 125 that is in agreement with the experimental data obtained by Belhafaf et al. These results are a consequence of the characteristics of the neutron emission, the variation in the primary fragment mean kinetic energy, and the yield as a function of the mass. (Author)
Energy Technology Data Exchange (ETDEWEB)
Montoya, M.; Rojas, J. [Instituto Peruano de Energia Nuclear, Av. Canada 1470, Lima 41 (Peru); Saettone, E. [Facultad de Ciencias, Universidad Nacional de lngenieria, Av. Tupac Amaru 210, Apartado 31-139, Lima (Peru)
2007-07-01
The mass and kinetic energy distribution of nuclear fragments from the thermal neutron-induced fission of {sup 235}U have been studied using a Monte Carlo simulation. Besides reproducing the pronounced broadening on the standard deviation of the final fragment kinetic energy distribution ({sigma}{sub e}(m)) around the mass number m = 109, our simulation also produces a second broadening around m = 125 that is in agreement with the experimental data obtained by Belhafaf et al. These results are a consequence of the characteristics of the neutron emission, the variation in the primary fragment mean kinetic energy, and the yield as a function of the mass. (Author)
Kinetic energy in the collective quadrupole Hamiltonian from the experimental data
Energy Technology Data Exchange (ETDEWEB)
Jolos, R.V., E-mail: jolos@theor.jinr.ru [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Dubna State University, 141980 Dubna (Russian Federation); Kolganova, E.A. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Dubna State University, 141980 Dubna (Russian Federation)
2017-06-10
Dependence of the kinetic energy term of the collective nuclear Hamiltonian on collective momentum is considered. It is shown that the fourth order in collective momentum term of the collective quadrupole Hamiltonian generates a sizable effect on the excitation energies and the matrix elements of the quadrupole moment operator. It is demonstrated that the results of calculation are sensitive to the values of some matrix elements of the quadrupole moment. It stresses the importance for a concrete nucleus to have the experimental data for the reduced matrix elements of the quadrupole moment operator taken between all low lying states with the angular momenta not exceeding 4.
Rangel, Cipriano; Espinosa-Garcia, Joaquin
2018-02-07
Within the Born-Oppenheimer approximation a full-dimensional analytical potential energy surface, PES-2017, was developed for the gas-phase hydrogen abstraction reaction between the chlorine atom and ethane, which is a nine body system. This surface presents a valence-bond/molecular mechanics functional form dependent on 60 parameters and is fitted to high-level ab initio calculations. This reaction presents little exothermicity, -2.30 kcal mol -1 , with a low height barrier, 2.44 kcal mol -1 , and intermediate complexes in the entrance and exit channels. We found that the energetic description was strongly dependent on the ab initio level used and it presented a very flat topology in the entrance channel, which represents a theoretical challenge in the fitting process. In general, PES-2017 reproduces the ab initio information used as input, which is merely a test of self-consistency. As a first test of the quality of the PES-2017, a theoretical kinetics study was performed in the temperature range 200-1400 K using two approaches, i.e. the variational transition-state theory and quasi-classical trajectory calculations, with spin-orbit effects. The rate constants show reasonable agreement with experiments in the whole temperature range, with the largest differences at the lowest temperatures, and this behaviour agrees with previous theoretical studies, thus indicating the inherent difficulties in the theoretical simulation of the kinetics of the title reaction. Different sources of error were analysed, such as the limitations of the PES and theoretical methods, recrossing effects, and the tunnelling effect, which is negligible in this reaction, and the manner in which the spin-orbit effects were included in this non-relativistic study. We found that the variation of spin-orbit coupling along the reaction path, and the influence of the reactivity of the excited Cl( 2 P 1/2 ) state, have relative importance, but do not explain the whole discrepancy. Finally, the
Extracting a kinetic relation from the dynamics of a bistable chain
International Nuclear Information System (INIS)
Zhao, Qingze; Purohit, Prashant K
2014-01-01
We integrate Newton's second law for a chain of masses and bistable springs with a spinodal region with the goal of extracting a kinetic relation for propagating phase boundaries. Our numerical experiments correspond to the impact on a bar made of phase changing material. By reading off the spring extensions ahead and behind the phase boundaries in our numerical experiments, we compute a driving force and plot it as a function of the phase boundary velocity to get a kinetic relation. We then show that this kinetic relation results in solutions to Riemann problems in continuum bars that agree with the corresponding numerical experiments on the discrete mass–spring chain. We also integrate Langevin's equations of motion for the same chain of masses and springs to account for the presence of a heat bath at a fixed temperature. We find that the xt-plane looks similar to the purely mechanical numerical experiments at low temperatures but at high temperatures there is an increased incidence of random nucleation events. Using results from both impact and Riemann problems, we show that the kinetic relation is a function of the bath temperature. (paper)
Development of imploding liners with kinetic energies > 100 MJ and their applications
International Nuclear Information System (INIS)
Reinovsky, R.E.; Ekdahl, C.A.
1996-01-01
The Los Alamos program in High Energy Density Physics is developing high performance imploding liners as sources of high energy density environments for experimental physics applications. High performance liners are, for these purposes, liners with high velocity, 100 MJ or more kinetic energy at 20-50 MJ/cm of height. They must have sufficient azimuthal symmetry, axial uniformity and density to perform as high quality impactors on central, cylindrical targets. Scientific applications of such liners are numerous and varied. For example, the properties of materials at extreme energy densities can be assessed in such an experimental environment. The physics of plasmas near solid density can be studied and hydrodynamics experiments at high Mach number (above 5?) in materials that are near solid density and significantly ionized can be conducted. In addition, liners with substantial kinetic energy and good integrity at velocities of one to a few cm/microsec make good implosion drivers for fusion plasmas in the context of magnetized target fusion and MAGO
Evaluation of energy collapsing effect on reactor kinetics parameters by diffusion theory
International Nuclear Information System (INIS)
Unesaki, Hironobu
1989-01-01
Reactor kinetics parameters play an important role as scaling factors between observed and calculated reactivities in the analysis of reactor physics experiments. In this report, energy collapsing errors in two kinetic parameters, the effective delayed neutron fraction and the neutron life time, are investigated by means of the diffusion theory. Coarse group calculations are made for various energy group structures. Cores of various moderator-to-fuel volume ratios are selected to investigate the influence of neutron spectrum changes on the energy collapsing error. The energy collapsing errors in the effective delayed neutron fraction and neutron life time are much larger than those in k eff . This might be because the former two parameters are functions of both the foward and adjoint flux, whereas the latter is a function of the forward flux alone. The use of coarse constants will cause errors in both fluxes, and the resulting errors in the former will be much more emphasized. As the effective delayed neutron fraction is sensitive to the treatment of an energy region in the vicinity of the fission spectrum peak, the coarse group error in it might differ between cores with different enrichment and composition. Inaccurate weighting of group constants leads to neutron spectra which do not conserve the fine group spectra, and those errors will be emphasized in calculated integral parameters. (N.K.)
A method for ion distribution function evaluation using escaping neutral atom kinetic energy samples
International Nuclear Information System (INIS)
Goncharov, P.R.; Ozaki, T.; Veshchev, E.A.; Sudo, S.
2008-01-01
A reliable method to evaluate the probability density function for escaping atom kinetic energies is required for the analysis of neutral particle diagnostic data used to study the fast ion distribution function in fusion plasmas. Digital processing of solid state detector signals is proposed in this paper as an improvement of the simple histogram approach. Probability density function for kinetic energies of neutral particles escaping from the plasma has been derived in a general form taking into account the plasma ion energy distribution, electron capture and loss rates, superposition along the diagnostic sight line and the magnetic surface geometry. A pseudorandom number generator has been realized that enables a sample of escaping neutral particle energies to be simulated for given plasma parameters and experimental conditions. Empirical probability density estimation code has been developed and tested to reconstruct the probability density function from simulated samples assuming. Maxwellian and classical slowing down plasma ion energy distribution shapes for different temperatures and different slowing down times. The application of the developed probability density estimation code to the analysis of experimental data obtained by the novel Angular-Resolved Multi-Sightline Neutral Particle Analyzer has been studied to obtain the suprathermal particle distributions. The optimum bandwidth parameter selection algorithm has also been realized. (author)
Derivative analyticity relations and asymptotic energies
International Nuclear Information System (INIS)
Fischer, J.
1976-01-01
On the basis of general principles of the S-matrix theory theorems are derived showing that derivative analyticity relations analogous to those of Bronzen, Kane and Sukhatme hold at asymptotic energies if the high-energy limits of certain physical quantities exist
Housing-related lifestyle and energy saving
DEFF Research Database (Denmark)
Thøgersen, John
2017-01-01
of relevant background characteristics. A multivariate GLM analysis reveals that when differences in housing-related lifestyles are controlled, neither country of residence nor the interaction between lifestyle and country of residence influence energy saving innovativeness or everyday energy-saving efforts...
Shin, Seungha
All energy conversion inefficiencies begin with emission of resonant atomic motions, e.g., vibrations, and are declared as waste heat once these motions thermalize to equilibrium. The nonequilibrium energy occupancy of the vibrational modes can be targeted as a harvestable, low entropy energy source for direct conversion to electric energy. Since the lifetime of these resonant vibrations is short, special nanostructures are required with the appropriate tuning of the kinetics. These in turn require multiscale, multiphysics treatments. Atomic vibration is described with quasiparticle phonon in solid, and the optical phonon emission is dominant relaxation channel in semiconductors. These optical modes become over-occupied when their emission rate becomes larger than their decay rate, thus hindering energy relaxation and transport in devices. Effective removal of these phonons by drifting electrons is investigated by manipulating the electron distribution to have higher population in the low-energy states, thus allowing favorable phonon absorption. This is done through introduction, design and analysis of a heterobarrier conducting current, where the band gap is controlled by alloying, thus creating a spatial variation which is abrupt followed by a linear gradient (to ensure directed current). Self-consistent ensemble Monte Carlo simulations based on interaction kinetics between electron and phonon show that up to 19% of the phonon energy is converted to electric potential with an optimized GaAs/AlxGa1-xAs barrier structure over a range of current and electron densities, and this system is also verified through statistical entropy analysis. This direct energy conversion improves the device performance with lower operation temperature and enhances overall energy conversion efficiency. Through this study, the paradigm for harvesting the resonant atomic vibration is proposed, reversing the general role of phonon as only causing electric potential drop. Fundamentals
Energy Technology Data Exchange (ETDEWEB)
Zhang, S. [University of North Carolina at Charlotte, Charlotte, NC 28223 (United States); Providence High School, Charlotte, NC 28270 (United States); Su, L.Q.; Kon, J. [University of North Carolina at Charlotte, Charlotte, NC 28223 (United States); Gfroerer, T. [Davidson College, Davidson, NC 28035 (United States); Wanlass, M.W. [National Renewable Energy Laboratory, Golden, CO 80401 (United States); Zhang, Y., E-mail: yong.zhang@uncc.edu [University of North Carolina at Charlotte, Charlotte, NC 28223 (United States)
2017-05-15
Photoluminescence (PL) imaging has been shown to be an efficient technique for investigating carrier diffusion in semiconductors. In the past, the measurement was typically carried out by measuring at one wavelength (e.g., at the band gap) or simply the whole emission band. At room temperature in a semiconductor like GaAs, the band-to-band PL emission may occur in a spectral range over 200 meV, vastly exceeding the average thermal energy of about 26 meV. To investigate the potential dependence of the carrier diffusion on the carrier kinetic energy, we performed wavelength selective PL imaging on a GaAs double hetero-structure in a spectral range from about 70 meV above to 50 meV below the bandgap, extracting the carrier diffusion lengths at different PL wavelengths by fitting the imaging data to a theoretical model. The results clearly show that the locally generated carriers of different kinetic energies mostly diffuse together, maintaining the same thermal distribution throughout the diffusion process. Potential effects related to carrier density, self-absorption, lateral wave-guiding, and local heating are also discussed.
Adib, Artur B.
In the last two decades or so, a collection of results in nonequilibrium statistical mechanics that departs from the traditional near-equilibrium framework introduced by Lars Onsager in 1931 has been derived, yielding new fundamental insights into far-from-equilibrium processes in general. Apart from offering a more quantitative statement of the second law of thermodynamics, some of these results---typified by the so-called "Jarzynski equality"---have also offered novel means of estimating equilibrium quantities from nonequilibrium processes, such as free energy differences from single-molecule "pulling" experiments. This thesis contributes to such efforts by offering three novel results in nonequilibrium statistical mechanics: (a) The entropic analog of the Jarzynski equality; (b) A methodology for estimating free energies from "clamp-and-release" nonequilibrium processes; and (c) A directly measurable symmetry relation in chemical kinetics similar to (but more general than) chemical detailed balance. These results share in common the feature of remaining valid outside Onsager's near-equilibrium regime, and bear direct applicability in protein folding kinetics as well as in single-molecule free energy estimation.
Kinetic Risk Factors of Running-Related Injuries in Female Recreational Runners.
Napier, Christopher; MacLean, Christopher L; Maurer, Jessica; Taunton, Jack E; Hunt, Michael A
2018-05-30
Our objective was to prospectively investigate the association of kinetic variables with running-related injury (RRI) risk. Seventy-four healthy female recreational runners ran on an instrumented treadmill while 3D kinetic and kinematic data were collected. Kinetic outcomes were vertical impact transient, average vertical loading rate, instantaneous vertical loading rate, active peak, vertical impulse, and peak braking force (PBF). Participants followed a 15-week half-marathon training program. Exposure time (hours of running) was calculated from start of program until onset of injury, loss to follow-up, or end of program. After converting kinetic variables from continuous to ordinal variables based on tertiles, Cox proportional hazard models with competing risks were fit for each variable independently, before analysis in a forward stepwise multivariable model. Sixty-five participants were included in the final analysis, with a 33.8% injury rate. PBF was the only kinetic variable that was a significant predictor of RRI. Runners in the highest tertile (PBF recreational runners and should be considered as a target for gait retraining interventions. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Murray, Matthew J.; Ogden, Hannah M.; Mullin, Amy S.
2017-10-01
An optical centrifuge is used to generate an ensemble of CO2 super rotors with oriented angular momentum. The collision dynamics and energy transfer behavior of the super rotor molecules are investigated using high-resolution transient IR absorption spectroscopy. New multipass IR detection provides improved sensitivity to perform polarization-dependent transient studies for rotational states with 76 ≤ J ≤ 100. Polarization-dependent measurements show that the collision-induced kinetic energy release is spatially anisotropic and results from both near-resonant energy transfer between super rotor molecules and non-resonant energy transfer between super rotors and thermal molecules. J-dependent studies show that the extent and duration of the orientational anisotropy increase with rotational angular momentum. The super rotors exhibit behavior akin to molecular gyroscopes, wherein molecules with larger amounts of angular momentum are less likely to change their angular momentum orientation through collisions.
Kinetic energy distributions of sputtered neutral aluminum clusters: Al--Al6
International Nuclear Information System (INIS)
Coon, S.R.; Calaway, W.F.; Pellin, M.J.; Curlee, G.A.; White, J.M.
1992-01-01
Neutral aluminum clusters sputtered from polycrystalline aluminum were analyzed by laser postionization time-of-flight (TOF) mass spectrometry. The kinetic energy distributions of Al through Al 6 were measured by a neutrals time-of-flight technique. The interpretation of laser postionization TOF data to extract velocity and energy distributions is presented. The aluminum cluster distributions are qualitatively similar to previous copper cluster distribution measurements from our laboratory. In contrast to the steep high energy tails predicted by the single- or multiple- collision models, the measured cluster distributions have high energy power law dependences in the range of E -3 to E -4.5 . Correlated collision models may explain the substantial abundance of energetic clusters that are observed in these experiments. Possible influences of cluster fragmentation on the distributions are discussed
International Nuclear Information System (INIS)
Kobayashi, Tohru; Kato, Toshiyuki; Kurata-Nishimura, Mizuki; Matsuo, Yukari; Kawai, Jun; Motobayashi, Tohru; Hayashizaki, Yoshihide
2007-01-01
We report that the kinetic energy of samarium (Sm) atom and Sm + ion produced by femtosecond laser ablation of solid samarium is strongly dependent on the number of ablation laser shots in the range from 1 to 10. By ablating the fresh surface (i.e. 1st shot), we find the kinetic energy of both Sm and Sm + ion to be the largest (24 and 250 eV, respectively). Almost 10 times larger kinetic energy of Sm + ion than that of Sm clearly indicates the contribution of Coulomb explosion in the acceleration process. From the second shot, kinetic energies of Sm and Sm + ion are lower than those of the first shot and almost constant (ca. 12 and 80 eV, respectively). This behaviour suggests the change in the nature of the solid surface after femtosecond laser ablation, which can be explained by the amorphization of ablated sample surface reported in recent studies
Seino, Junji; Kageyama, Ryo; Fujinami, Mikito; Ikabata, Yasuhiro; Nakai, Hiromi
2018-06-01
A semi-local kinetic energy density functional (KEDF) was constructed based on machine learning (ML). The present scheme adopts electron densities and their gradients up to third-order as the explanatory variables for ML and the Kohn-Sham (KS) kinetic energy density as the response variable in atoms and molecules. Numerical assessments of the present scheme were performed in atomic and molecular systems, including first- and second-period elements. The results of 37 conventional KEDFs with explicit formulae were also compared with those of the ML KEDF with an implicit formula. The inclusion of the higher order gradients reduces the deviation of the total kinetic energies from the KS calculations in a stepwise manner. Furthermore, our scheme with the third-order gradient resulted in the closest kinetic energies to the KS calculations out of the presented functionals.
DEFF Research Database (Denmark)
Buchhave, Preben; Velte, Clara Marika
2017-01-01
distortions caused by Taylor’s hypothesis. The method is first confirmed to produce the correct statistics using computer simulations and later applied to measurements in some of the most difficult regions of a round turbulent jet—the non-equilibrium developing region and the outermost parts of the developed......We present a method for converting a time record of turbulent velocity measured at a point in a flow to a spatial velocity record consisting of consecutive convection elements. The spatial record allows computation of dynamic statistical moments such as turbulent kinetic wavenumber spectra...... and spatial structure functions in a way that completely bypasses the need for Taylor’s hypothesis. The spatial statistics agree with the classical counterparts, such as the total kinetic energy spectrum, at least for spatial extents up to the Taylor microscale. The requirements for applying the method...
Exploring the Invisible Renormalon Renormalization of the Heavy-Quark Kinetic Energy
Neubert, M
1997-01-01
Using the virial theorem of the heavy-quark effective theory, we show that the mixing of the operator for the heavy-quark kinetic energy with the identity operator is forbidden at the one-loop order by Lorentz invariance. This explains why such a mixing was not observed in several one-loop calculations using regularization schemes with a Lorentz-invariant UV regulator, and why no UV renormalon singularity was found in the matrix elements of the kinetic operator in the bubble approximation (the ``invisible renormalon''). On the other hand, we show that the mixing is not protected in general by any symmetry, and it indeed occurs at the two-loop order. This implies that the parameter $\\lambda_1^H$ of the heavy-quark effective theory is not directly a physical quantity, but requires a non-perturbative subtraction.
Russian- Chinese relations : towards an energy partnership
Garanina, Olga
2007-01-01
18 p.; This paper aims to investigate the Russian-Chinese energy relations in the context of evolution of bilateral strategic relations since 1991.The research is focused on Russia and encompasses three main aspects: strategic approach of Russian-Chinese relations, Russian hydrocarbons production and export potential and prospects for the Eastern Russia. The paper is based on qualitative analysis. It shows that the framework of bilateral relations is globally favourable for creation of costly...
Mouchtouris, S.; Kokkoris, G.
2018-01-01
A generalized equation for the electron energy probability function (EEPF) of inductively coupled Ar plasmas is proposed under conditions of nonlocal electron kinetics and diffusive cooling. The proposed equation describes the local EEPF in a discharge and the independent variable is the kinetic energy of electrons. The EEPF consists of a bulk and a depleted tail part and incorporates the effect of the plasma potential, Vp, and pressure. Due to diffusive cooling, the break point of the EEPF is eVp. The pressure alters the shape of the bulk and the slope of the tail part. The parameters of the proposed EEPF are extracted by fitting to measure EEPFs (at one point in the reactor) at different pressures. By coupling the proposed EEPF with a hybrid plasma model, measurements in the gaseous electronics conference reference reactor concerning (a) the electron density and temperature and the plasma potential, either spatially resolved or at different pressure (10-50 mTorr) and power, and (b) the ion current density of the electrode, are well reproduced. The effect of the choice of the EEPF on the results is investigated by a comparison to an EEPF coming from the Boltzmann equation (local electron kinetics approach) and to a Maxwellian EEPF. The accuracy of the results and the fact that the proposed EEPF is predefined renders its use a reliable alternative with a low computational cost compared to stochastic electron kinetic models at low pressure conditions, which can be extended to other gases and/or different electron heating mechanisms.
Uncertainty in relative energy resolution measurements
International Nuclear Information System (INIS)
Volkovitsky, P.; Yen, J.; Cumberland, L.
2007-01-01
We suggest a new method for the determination of the detector relative energy resolution and its uncertainty based on spline approximation of experimental spectra and a statistical bootstrapping procedure. The proposed method is applied to the spectra obtained with NaI(Tl) scintillating detectors and 137 Cs sources. The spectrum histogram with background subtracted channel-by-channel is modeled by cubic spline approximation. The relative energy resolution (which is also known as pulse height resolution and energy resolution), defined as the full-width at half-maximum (FWHM) divided by the value of peak centroid, is calculated using the intercepts of the spline curve with the line of the half peak height. The value of the peak height is determined as the point where the value of the derivative goes to zero. The residuals, which are normalized over the square root of counts in a given bin (y-coordinate), obey the standard Gaussian distribution. The values of these residuals are randomly re-assigned to a different set of y-coordinates where a new 'pseudo-experimental' data set is obtained after 'de-normalization' of the old values. For this new data set a new spline approximation is found and the whole procedure is repeated several hundred times, until the standard deviation of relative energy resolution becomes stabilized. The standard deviation of relative energy resolutions calculated for each 'pseudo-experimental' data set (bootstrap uncertainty) is considered to be an estimate for relative energy resolution uncertainty. It is also shown that the relative bootstrap uncertainty is proportional to, and generally only two to three times bigger than, 1/√(N tot ), which is the relative statistical count uncertainty (N tot is the total number of counts under the peak). The newly suggested method is also applicable to other radiation and particle detectors, not only for relative energy resolution, but also for any of the other parameters in a measured spectrum, like
International Nuclear Information System (INIS)
Shibuya, Kengo; Kawamura, Yoshihiro; Saito, Haruo
2015-01-01
Positronium(Ps) can undergo ortho-para spin conversion reaction during Ps-Xecollisions due to spin-orbit interaction. We have investigated energy dependence of this reaction rate and found it is nearly proportional to T 2.1 , where T is the temperature (300-623 K), while the pick-off annihilation rate is proportional to T. The strong temperature dependence of the former annihilation rate is attributed to a nature of p-wave scattering because this reaction is forbidden in s-wave scattering. In addition, a new method for measuring Ps kinetic energy has been developed with a high resolution and a high sensitivity by utilizing the strong temperature dependence as a 'thermometer.' Analyzingthe obtained time evolution of Ps kinetic energy, we have determined the momentum transfer cross section during Ps-Xecollisions at a very low energy (40-60 meV) to be 12(2)×10 −16 cm 2 . (paper)
Ground, Cody; Vergine, Fabrizio; Maddalena, Luca
2016-08-01
A defining feature of the turbulent free shear layer is that its growth is hindered by compressibility effects, thus limiting its potential to sufficiently mix the injected fuel and surrounding airstream at the supersonic Mach numbers intrinsic to the combustor of air-breathing hypersonic vehicles. The introduction of streamwise vorticity is often proposed in an attempt to counteract these undesired effects. This fact makes the strategy of introducing multiple streamwise vortices and imposing upon them certain modes of mutual interaction in order to potentially enhance mixing an intriguing concept. However, many underlying fundamental characteristics of the flowfields in the presence such interactions are not yet well understood; therefore, the fundamental physics of these flowfields should be independently investigated before the explicit mixing performance is characterized. In this work, experimental measurements are taken with the stereoscopic particle image velocimetry technique on two specifically targeted modes of vortex interaction—the merging and non-merging of two corotating vortices. The fluctuating velocity fields are analyzed utilizing the proper orthogonal decomposition (POD) in order to identify the content, organization, and distribution of the modal turbulent kinetic energy content of the fluctuating velocity eigenmodes. The effects of the two modes of vortex interaction are revealed by the POD analysis which shows distinct differences in the modal features of the two cases. When comparing the low-order eigenmodes of the two cases, the size of the structures contained within the first ten modes is seen to increase as the flow progresses downstream for the merging case, whereas the opposite is true for the non-merging case. Additionally, the relative modal energy contribution of the first ten eigenmodes increases as the vortices evolve downstream for the merging case, whereas in the non-merging case the relative modal energy contribution decreases
Energy and Uncertainty in General Relativity
Cooperstock, F. I.; Dupre, M. J.
2018-03-01
The issue of energy and its potential localizability in general relativity has challenged physicists for more than a century. Many non-invariant measures were proposed over the years but an invariant measure was never found. We discovered the invariant localized energy measure by expanding the domain of investigation from space to spacetime. We note from relativity that the finiteness of the velocity of propagation of interactions necessarily induces indefiniteness in measurements. This is because the elements of actual physical systems being measured as well as their detectors are characterized by entire four-velocity fields, which necessarily leads to information from a measured system being processed by the detector in a spread of time. General relativity adds additional indefiniteness because of the variation in proper time between elements. The uncertainty is encapsulated in a generalized uncertainty principle, in parallel with that of Heisenberg, which incorporates the localized contribution of gravity to energy. This naturally leads to a generalized uncertainty principle for momentum as well. These generalized forms and the gravitational contribution to localized energy would be expected to be of particular importance in the regimes of ultra-strong gravitational fields. We contrast our invariant spacetime energy measure with the standard 3-space energy measure which is familiar from special relativity, appreciating why general relativity demands a measure in spacetime as opposed to 3-space. We illustrate the misconceptions by certain authors of our approach.
Observed near-inertial kinetic energy in the northwestern South China Sea
Chen, Gengxin; Xue, Huijie; Wang, Dongxiao; Xie, Qiang
2013-10-01
Based on more than 3 years of moored current-meter records, this study examined seasonal variability of near-inertial kinetic energy (NIKE) as well as all large (greater than one standard deviation from the mean) NIKE events related to storms and eddies in the northwestern South China Sea. The NIKE in the subsurface layer (30-450 m) exhibited obvious seasonal variability with larger values in autumn (herein defined as August, September, and October). All large NIKE events during the observation period were generated by passing storms. Most of the NIKE events had an e-folding timescale longer than 7 d. The phase velocity, vertical wavelength, and frequency shift of these events were examined. The maximum NIKE, induced by typhoon "Neoguri," was observed in April 2008. Normal mode analysis suggested that the combined effects of the first four modes determined the vertical distribution of NIKE with higher NIKE below 70 m but lower NIKE from 30 to 70 m. Another near-inertial oscillation event observed in August 2007 had the longest e-folding timescale of 13.5 d. Moreover, the NIKE propagated both upward and downward during this event. A ray-tracing model indicated that the smaller Brunt-Väisälä frequency and the stronger vertical shear of horizontal currents in an anticyclonic eddy and the near-inertial wave with larger horizontal scale facilitated the unusual propagation of the NIKE and the long decay timescale. Although the NIKE originated from wind, the water column structure affected by diverse oceanographic processes contributed substantially to its complex propagation and distribution.
Energy Vulnerability and EU-Russia Energy Relations
Directory of Open Access Journals (Sweden)
Edward Hunter Christie
2009-08-01
Full Text Available The concept of energy vulnerability is reviewed and discussed with a focus on Russia’s foreign energy relations, in particular those with European countries. A definition and a conceptual framework for quantifying energy vulnerability are proposed in the context of a review of recent research on energy vulnerability indices. In particular it is suggested that source country diversification should be reflected using the expected shortfall measure used in financial economics, rather than the Herfindahl-Hirschman or Shannon-Wiener indices, and that the former should then enter a calibrated function in order to yield expected economic loss. The issues of asymmetric failure probabilities and accidental versus intentional supply disruptions are then discussed with examples of recent Russian actions. Energy vulnerability measurement and modelling should ultimately inform policy. In particular, member states should legislate that no energy infrastructure project by one or more member states may increase the energy vulnerability of another member state. Additionally, European environmental policies, notably the EU ETS, should be amended so as to account for induced changes in energy vulnerability. Finally, member states should increase the level of transparency and disclosure with respect to gas import statistics and gas supply contracts.
Sensory Agreement Guides Kinetic Energy Optimization of Arm Movements during Object Manipulation.
Directory of Open Access Journals (Sweden)
Ali Farshchiansadegh
2016-04-01
Full Text Available The laws of physics establish the energetic efficiency of our movements. In some cases, like locomotion, the mechanics of the body dominate in determining the energetically optimal course of action. In other tasks, such as manipulation, energetic costs depend critically upon the variable properties of objects in the environment. Can the brain identify and follow energy-optimal motions when these motions require moving along unfamiliar trajectories? What feedback information is required for such optimal behavior to occur? To answer these questions, we asked participants to move their dominant hand between different positions while holding a virtual mechanical system with complex dynamics (a planar double pendulum. In this task, trajectories of minimum kinetic energy were along curvilinear paths. Our findings demonstrate that participants were capable of finding the energy-optimal paths, but only when provided with veridical visual and haptic information pertaining to the object, lacking which the trajectories were executed along rectilinear paths.
International Nuclear Information System (INIS)
Lee, H.; Wu, C.-Y.; Yang, S.K.; Lee, Y.-P.
2005-01-01
Following photodissociation of formyl fluoride (HFCO) at 193 nm, we detected products with fragmentation translational spectroscopy utilizing a tunable vacuum ultraviolet beam from a synchrotron for ionization. Among three primary dissociation channels observed in this work, the F-elimination channel HFCO→HCO+F dominates, with a branching ratio ∼0.66 and an average release of kinetic energy ∼55 kJ mol -1 ; about 17% of HCO further decomposes to H+CO. The H-elimination channel HFCO→FCO+H has a branching ratio ∼0.28 and an average release of kinetic energy ∼99 kJ mol -1 ; about 21% of FCO further decomposes to F+CO. The F-elimination channel likely proceeds via the S 1 surface whereas the H-elimination channel proceeds via the T 1 surface; both channels exhibit moderate barriers for dissociation. The molecular HF-elimination channel HFCO→HF+CO, correlating with the ground electronic surface, has a branching ratio of only ∼0.06; the average translational release of 93 kJ mol -1 , ∼15% of available energy, implies that the fragments are highly internally excited. Detailed mechanisms of photodissociation are discussed
First lattice calculation of the B-meson binding and kinetic energies
Crisafulli, M; Martinelli, G; Sachrajda, Christopher T C
1995-01-01
We present the first lattice calculation of the B-meson binding energy \\labar and of the kinetic energy -\\lambda_1/2 m_Q of the heavy-quark inside the pseudoscalar B-meson. This calculation has required the non-perturbative subtraction of the power divergences present in matrix elements of the Lagrangian operator \\bar h D_4 h and of the kinetic energy operator \\bar h \\vec D^2 h. The non-perturbative renormalisation of the relevant operators has been implemented by imposing suitable renormalisation conditions on quark matrix elements, in the Landau gauge. Our numerical results have been obtained from several independent numerical simulations at \\beta=6.0 and 6.2, and using, for the meson correlators, the results obtained by the APE group at the same values of \\beta. Our best estimate, obtained by combining results at different values of \\beta, is \\labar =190 \\err{50}{30} MeV. For the \\overline{MS} running mass, we obtain \\overline {m}_b(\\overline {m}_b) =4.17 \\pm 0.06 GeV, in reasonable agreement with previous...
Organometallics and related molecules for energy conversion
Wong, Wai-Yeung
2015-01-01
This book presents a critical perspective of the applications of organometallic compounds (including those with metal or metalloid elements) and other related metal complexes as versatile functional materials in the transformation of light into electricity (solar energy conversion) and electricity into light (light generation in light emitting diode), in the reduction of carbon dioxide to useful chemicals, as well as in the safe and efficient production and utilization of hydrogen, which serves as an energy storage medium (i.e. energy carrier). This book focuses on recent research developmen
Releasable Kinetic Energy-Based Inertial Control of a DFIG Wind Power Plant
DEFF Research Database (Denmark)
Lee, Jinsik; Muljadi, Eduard; Sørensen, Poul Ejnar
2016-01-01
Wind turbine generators (WTGs) in a wind power plant (WPP) contain different levels of releasable kinetic energy (KE) because of the wake effects. This paper proposes a releasable KE-based inertial control scheme for a doubly fed induction generator (DFIG) WPP that differentiates the contributions....... The proposed scheme adjusts the two loop gains in a DFIG controller depending on its rotor speed so that a DFIG operating at a higher rotor speed releases more KE. The performance of the proposed scheme was investigated under various wind conditions. The results clearly indicate that the proposed scheme...
Anomalous dissipation and kinetic-energy distribution in pipes at very high Reynolds numbers.
Chen, Xi; Wei, Bo-Bo; Hussain, Fazle; She, Zhen-Su
2016-01-01
A symmetry-based theory is developed for the description of (streamwise) kinetic energy K in turbulent pipes at extremely high Reynolds numbers (Re's). The theory assumes a mesolayer with continual deformation of wall-attached eddies which introduce an anomalous dissipation, breaking the exact balance between production and dissipation. An outer peak of K is predicted above a critical Re of 10^{4}, in good agreement with experimental data. The theory offers an alternative explanation for the recently discovered logarithmic distribution of K. The concept of anomalous dissipation is further supported by a significant modification of the k-ω equation, yielding an accurate prediction of the entire K profile.
Relative rate study of the kinetic isotope effect in the 13CH3D + Cl reaction
DEFF Research Database (Denmark)
Joelsson, Lars Magnus Torvald; Forecast, Roslyn; Schmidt, Johan Albrecht
2014-01-01
The 13CH3D/12CH4kinetic isotope effect, α13CH3D, of CH4 + Cl is determined for the first time, using the relative rate technique and Fourier transform infrared (FTIR) spectroscopy. α13CH3D is found to be 1.60 ± 0.04. In addition, a quantum chemistry/transition state theory model with tunneling...
Relative energy for the Korteweg theory and related Hamiltonian flows in gas dynamics
Giesselmann, Jan; Lattanzio, Corrado; Tzavaras, Athanasios
2016-01-01
For an Euler system, with dynamics generated by a potential energy functional, we propose a functional format for the relative energy and derive a relative energy identity. The latter, when applied to specific energies, yields relative energy
Kinetic energy of shakeoff atomic electrons from 37K β+ decay
Behr, J. A.; Gorelov, A.; Farfan, C.; Smale, S.; Olchanski, K.; Kurchananov, L.; Anholm, M.; Behling, R. S.; Fenker, B.; Shidling, P. D.; Mehlman, M.; Melconian, D.; Ashery, D.; Gwinner, G.; Trinat Collaboration
2013-10-01
We have measured the kinetic energies from 0 to 30 eV of atomic shakeoff electrons from the β+ decay of 37K. Despite much experimental and theoretical work on the distribution of final ion charge states, shakeoff electrons from β- decay have only been measured with energies above 150 eV [Mitrokhovich, Nucl. Phys. Atom. Energy, 11, 125 (2010)]. We use our magneto-optical trap's time-varying magnetic quadrupole field combined with a uniform electric field as a spectrometer. Our result has more 15 eV electrons than a model using the sudden approximation and hydrogenic wavefunctions [Levinger, Phys. Rev. 90, 11 (1958)]. The total energy carried away by electrons is, as expected, a negligible correction to superallowed Ft values. Understanding the energy of these low-energy electrons is important for their use in precision β decay to select events coming from trapped atoms and start time-of-flight for the recoil ions. Our results could provide a benchmark for shakeoff electron calculations used for biological radiation damage [Lee, Comp. Math. Meth in Medicine doi:10.1155/2012/651475]. Support: NSERC, NRC through TRIUMF, DOE ER41747 ER40773, State of Texas, Israel Science Foundation.
Precise control of Si(001) initial oxidation by translational kinetic energy of O2 molecules
International Nuclear Information System (INIS)
Teraoka, Yuden; Yoshigoe, Akitaka
2002-01-01
The influence of translation kinetic energy of incident O 2 molecules on the passive oxidation of the clean Si(001) surface and the partially oxidized-Si(001) surface has been studied by high-resolution photoemission spectroscopy using synchrotron radiation. The incident energy of O 2 molecules was controlled up to 3 eV by a supersonic seeded molecular beam technique. Although two incident energy thresholds (1.0 eV and 2.6 eV) have been determined for the partially oxidized-surface oxidation in accordance with the first-principle calculation, the monotonic increase of oxygen saturation coverage was observed for the clean surface oxidation. The difference is caused by the initial dangling bond termination (Si-H and Si-OH) on the partially oxidized surface. Si-2p and O-1s photoemission spectra measured at representative incident energies showed the incident-energy-induced oxidation at the back bonds of Si dimers and the second-layer (subsurface) Si atoms. Moreover, the low-and high-binding-energy components in the O-1s photoemission spectra were assigned to bridge site oxygen and dangling bond site oxygen for the partially oxidized-surface oxidation. (author)
Yu-Jen, Wang; Tsung-Yi, Chuang; Jui-Hsin, Yu
2017-09-01
Vibration-based energy harvesters have been developed as power sources for wireless sensor networks. Because the vibration frequency of the environment is varied with surrounding conditions, how to design an adaptive energy harvester is a practical topic. This paper proposes a design for a piezoelectric energy harvester possessing the ability to self-adjust its resonant frequency in rotational environments. The effective length of a trapezoidal cantilever is extended by centrifugal force from a rotating wheel to vary its area moment of inertia. The analytical solution for the natural frequency of the piezoelectric energy harvester was derived from the parameter design process, which could specify a structure approaching resonance at any wheel rotating frequency. The kinetic equation and electrical damping induced by power generation were derived from a Lagrange method and a mechanical-electrical coupling model, respectively. An energy harvester with adequate parameters can generate power at a wide range of car speeds. The output power of an experimental prototype composed of piezoelectric thin films and connected to a 3.3 MΩ external resistor was approximately 70-140 μW at wheel speeds ranging from 200 to 700 RPM. These results demonstrate that the proposed piezoelectric energy harvester can be applied as a power source for the wireless tire pressure monitoring sensor.
Dyverfeldt, Petter; Hope, Michael D; Tseng, Elaine E; Saloner, David
2013-01-01
The authors sought to measure the turbulent kinetic energy (TKE) in the ascending aorta of patients with aortic stenosis and to assess its relationship to irreversible pressure loss. Irreversible pressure loss caused by energy dissipation in post-stenotic flow is an important determinant of the hemodynamic significance of aortic stenosis. The simplified Bernoulli equation used to estimate pressure gradients often misclassifies the ventricular overload caused by aortic stenosis. The current gold standard for estimation of irreversible pressure loss is catheterization, but this method is rarely used due to its invasiveness. Post-stenotic pressure loss is largely caused by dissipation of turbulent kinetic energy into heat. Recent developments in magnetic resonance flow imaging permit noninvasive estimation of TKE. The study was approved by the local ethics review board and all subjects gave written informed consent. Three-dimensional cine magnetic resonance flow imaging was used to measure TKE in 18 subjects (4 normal volunteers, 14 patients with aortic stenosis with and without dilation). For each subject, the peak total TKE in the ascending aorta was compared with a pressure loss index. The pressure loss index was based on a previously validated theory relating pressure loss to measures obtainable by echocardiography. The total TKE did not appear to be related to global flow patterns visualized based on magnetic resonance-measured velocity fields. The TKE was significantly higher in patients with aortic stenosis than in normal volunteers (p < 0.001). The peak total TKE in the ascending aorta was strongly correlated to index pressure loss (R(2) = 0.91). Peak total TKE in the ascending aorta correlated strongly with irreversible pressure loss estimated by a well-established method. Direct measurement of TKE by magnetic resonance flow imaging may, with further validation, be used to estimate irreversible pressure loss in aortic stenosis. Copyright © 2013 American
Energy Technology Data Exchange (ETDEWEB)
Wilson, Jacqueline M.; Imre, D.; Beranek, Josef; Shrivastava, ManishKumar B.; Zelenyuk, Alla
2015-01-06
Secondary organic aerosols (SOA) dominate atmospheric organic aerosols that affect climate, air quality, and health. Recent studies indicate that, contrary to previously held assumptions, at low relative humidity (RH) these particles are semi-solid and evaporate orders of magnitude slower than expected. Elevated relative humidity has the potential to affect significantly formation, properties, and atmospheric evolution of SOA particles. Here we present a study of the effect of RH on the room-temperature evaporation kinetics of SOA particles formed by ozonolysis of α-pinene and limonene. Experiments were carried out on SOA particles generated, evaporated, and aged at 0%, 50% and 90% RH. We find that in all cases evaporation begins with a relatively fast phase, during which 30% to 70% of the particle mass evaporates in 2 hours, followed by a much slower evaporation rate. Evaporation kinetics at 0% and 50% RH are nearly the same, while at 90% RH a slightly larger fraction evaporates. In all cases, aging the particles prior to inducing evaporation reduces the evaporative losses, with aging at elevated RH leading to more significant effect. In all cases, SOA evaporation is nearly size-independent, providing direct evidence that oligomers play a crucial role in determining the evaporation kinetics.
Kovacs effect and fluctuation-dissipation relations in 1D kinetically constrained models
International Nuclear Information System (INIS)
Buhot, Arnaud
2003-01-01
Strong and fragile glass relaxation behaviours are obtained simply changing the constraints of the kinetically constrained Ising chain from symmetric to purely asymmetric. We study the out-of-equilibrium dynamics of these two models focusing on the Kovacs effect and the fluctuation-dissipation (FD) relations. The Kovacs or memory effect, commonly observed in structural glasses, is present for both constraints but enhanced with the asymmetric ones. Most surprisingly, the related FD relations satisfy the FD theorem in both cases. This result strongly differs from the simple quenching procedure where the asymmetric model presents strong deviations from the FD theorem
Jointly Sponsored Research Program Energy Related Research
Energy Technology Data Exchange (ETDEWEB)
Western Research Institute
2009-03-31
Cooperative Agreement, DE-FC26-98FT40323, Jointly Sponsored Research (JSR) Program at Western Research Institute (WRI) began in 1998. Over the course of the Program, a total of seventy-seven tasks were proposed utilizing a total of $23,202,579 in USDOE funds. Against this funding, cosponsors committed $26,557,649 in private funds to produce a program valued at $49,760,228. The goal of the Jointly Sponsored Research Program was to develop or assist in the development of innovative technology solutions that will: (1) Increase the production of United States energy resources - coal, natural gas, oil, and renewable energy resources; (2) Enhance the competitiveness of United States energy technologies in international markets and assist in technology transfer; (3) Reduce the nation's dependence on foreign energy supplies and strengthen both the United States and regional economies; and (4) Minimize environmental impacts of energy production and utilization. Under the JSR Program, energy-related tasks emphasized enhanced oil recovery, heavy oil upgrading and characterization, coal beneficiation and upgrading, coal combustion systems development including oxy-combustion, emissions monitoring and abatement, coal gasification technologies including gas clean-up and conditioning, hydrogen and liquid fuels production, coal-bed methane recovery, and the development of technologies for the utilization of renewable energy resources. Environmental-related activities emphasized cleaning contaminated soils and waters, processing of oily wastes, mitigating acid mine drainage, and demonstrating uses for solid waste from clean coal technologies, and other advanced coal-based systems. Technology enhancement activities included resource characterization studies, development of improved methods, monitors and sensors. In general the goals of the tasks proposed were to enhance competitiveness of U.S. technology, increase production of domestic resources, and reduce environmental
Energy Transfer Kinetics in Photosynthesis as an Inspiration for Improving Organic Solar Cells.
Nganou, Collins; Lackner, Gerhard; Teschome, Bezu; Deen, M Jamal; Adir, Noam; Pouhe, David; Lupascu, Doru C; Mkandawire, Martin
2017-06-07
Clues to designing highly efficient organic solar cells may lie in understanding the architecture of light-harvesting systems and exciton energy transfer (EET) processes in very efficient photosynthetic organisms. Here, we compare the kinetics of excitation energy tunnelling from the intact phycobilisome (PBS) light-harvesting antenna system to the reaction center in photosystem II in intact cells of the cyanobacterium Acaryochloris marina with the charge transfer after conversion of photons into photocurrent in vertically aligned carbon nanotube (va-CNT) organic solar cells with poly(3-hexyl)thiophene (P3HT) as the pigment. We find that the kinetics in electron hole creation following excitation at 600 nm in both PBS and va-CNT solar cells to be 450 and 500 fs, respectively. The EET process has a 3 and 14 ps pathway in the PBS, while in va-CNT solar cell devices, the charge trapping in the CNT takes 11 and 258 ps. We show that the main hindrance to efficiency of va-CNT organic solar cells is the slow migration of the charges after exciton formation.
Kinetic energy classification and smoothing for compact B-spline basis sets in quantum Monte Carlo
Krogel, Jaron T.; Reboredo, Fernando A.
2018-01-01
Quantum Monte Carlo calculations of defect properties of transition metal oxides have become feasible in recent years due to increases in computing power. As the system size has grown, availability of on-node memory has become a limiting factor. Saving memory while minimizing computational cost is now a priority. The main growth in memory demand stems from the B-spline representation of the single particle orbitals, especially for heavier elements such as transition metals where semi-core states are present. Despite the associated memory costs, splines are computationally efficient. In this work, we explore alternatives to reduce the memory usage of splined orbitals without significantly affecting numerical fidelity or computational efficiency. We make use of the kinetic energy operator to both classify and smooth the occupied set of orbitals prior to splining. By using a partitioning scheme based on the per-orbital kinetic energy distributions, we show that memory savings of about 50% is possible for select transition metal oxide systems. For production supercells of practical interest, our scheme incurs a performance penalty of less than 5%.
International Nuclear Information System (INIS)
Neumann, Martin; Zoppi, Marco
2002-01-01
We have performed extensive path integral Monte Carlo simulations of liquid and solid neon, in order to derive the kinetic energy as well as the single-particle and pair distribution functions of neon atoms in the condensed phases. From the single-particle distribution function n(r) one can derive the momentum distribution and thus obtain an independent estimate of the kinetic energy. The simulations have been carried out using mostly the semiempirical HFD-C2 pair potential by Aziz et al. [R. A. Aziz, W. J. Meath, and A. R. Allnatt, Chem. Phys. 79, 295 (1983)], but, in a few cases, we have also used the Lennard-Jones potential. The differences between the potentials, as measured by the properties investigated, are not very large, especially when compared with the actual precision of the experimental data. The simulation results have been compared with all the experimental information that is available from neutron scattering. The overall agreement with the experiments is very good
Energy Technology Data Exchange (ETDEWEB)
Kusuoka, Hideo; Tsuneoka, Yutaka; Inoue, Michitoshi; Abe, Hiroshi [Osaka Univ. (Japan). Faculty of Medicine; Watari, Hiroshi
1982-12-01
Effect of artificial blood, FC 43 (Perfluorochemicals) on the kinetics of high-energy phosphate in the myocardium was evaluated by /sup 31/P-NMR which permits a continuous and non-invasive assessment of in vivo phosphorus compounds. Cardiac perfusion was carried out on a excised rat heart with a Krebs-Henseleit modified solution and FC 43 alternately. Under the normal condition, ischemic condition, and at second perfusion amounts of intramyocardial creatine phosphoric acid, ATP, and inorganic phosphorus were determined by /sup 31/P-NMR. Coronary flow was simultaneously estimated. The ischemic state due to interruption of perfusion resulted in a decrease in creatine phosphoric acid, which was associated with an increase in inorganic phosphorus and intracellular acidosis. No change of ATP amount was observed under ischemic state. With resumption of perfusion, the levels of creatine phosphoric acid and inorganic phosphorus rapidly returned to the normal. In the group of FC 43, coronary flow was 2.68 ml/min/g of the heart weight, about 1/2 of that of the Krebs-Henseleit group (5.68 ml/min/g of the heart weight). In controls, there was no difference between the two groups concerning creatine phosphoric acid level and recovery of creatine phospohric acid level after ischemia. These results showed that FC 43 supplies sufficient oxygen, and has no effect on the kinetics of energy in the myocardium.
Circulating follistatin in relation to energy metabolism
DEFF Research Database (Denmark)
Hansen, Jakob Schiøler; Plomgaard, Peter
2016-01-01
a relation to energy metabolism. In this narrative review, we attempt to reconcile the existing findings on circulating follistatin with the novel concept that circulating follistatin is a liver-derived molecule regulated by the glucagon-to-insulin ratio. The picture emerging is that conditions associated...
Current redistribution and generation of kinetic energy in the stagnated Z pinch.
Ivanov, V V; Anderson, A A; Papp, D; Astanovitskiy, A L; Talbot, B R; Chittenden, J P; Niasse, N
2013-07-01
The structure of magnetic fields was investigated in stagnated wire-array Z pinches using a Faraday rotation diagnostic at the wavelength of 266 nm. The distribution of current in the pinch and trailing material was reconstructed. A significant part of current can switch from the main pinch to the trailing plasma preheated by x-ray radiation of the pinch. Secondary implosions of trailing plasma generate kinetic energy and provide enhanced heating and radiation of plasma at stagnation. Hot spots in wire-array Z pinches also provide enhanced radiation of the Z pinch. A collapse of a single hot spot radiates 1%-3% of x-ray energy of the Z pinch with a total contribution of hot spots of 10%-30%.
Evaluation of energy related risk acceptance (APHA energy task force)
International Nuclear Information System (INIS)
Hull, A.P.
1977-01-01
Living in a technological society with large energy requirements involves a number of related actities with attendant health risks, both to the working and to the general public. Therefore, the formulation of some general principles for risk acceptance is necessary. In addition to maximizing benefits and minimizing risk, relevant considerations must be made about the perception of risk as voluntary or involuntary, the number of persons collectively at risk at any one occasion, and the extent to which a risk is a familiar one. With regard to a given benefit, such as a given amount of energy, comparisons of the risks of alternate modes of production may be utilized. However, cost-benefit consideration is essential to the amelioration of current or prospective risks. This is unusual, since it is based on some estimate of the monetary value per premature death averted. It is proposed that increased longevity would be a more satisfactory measure. On a societal basis, large expenditures for additional energy-related pollution control do not appear justifiable since much larger, nonenergy-related health risks are relatively underaddressed. Knowledgeable health professionals could benefit the public by imparting authoritative information in this area
Spontaneous transfer of magnetically stored energy to Kinetic energy by electric double layers
International Nuclear Information System (INIS)
Lindberg, L.; Torven, S.
1983-05-01
Current disruptions are investigated in a magnetized plasma column with an inductive external electric circuit. It is found that they persist in spite of the fact that each disruption gives rise to a large inductive over-voltage. This drops off at an electric double layer formed in the plasma where most of the magnetic energy, initially stored in the circuit inductance, is released as particle energy. Simultanously as the current disrupts, the potential level at a local potential minimum in the plasma decreases. This is expected to cause the disruption by reflection of electrons. (authors)
Recovery Estimation of Dried Foodborne Pathogens Is Directly Related to Rehydration Kinetics
Lang, Emilie; Zoz, Fiona; Iaconelli, Cyril; Guyot, Stéphane; Alvarez-Martin, Pablo; Beney, Laurent; Perrier-Cornet, Jean-Marie; Gervais, Patrick
2016-01-01
Drying is a common process which is used to preserve food products and technological microorganisms, but which is deleterious for the cells. The aim of this study is to differentiate the effects of drying alone from the effects of the successive and necessary rehydration. Rehydration of dried bacteria is a critical step already studied in starter culture but not for different kinetics and not for pathogens. In the present study, the influence of rehydration kinetics was investigated for three foodborne pathogens involved in neonatal diseases caused by the consumption of rehydrated milk powder: Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica serovar Senftenberg and Cronobacter sakazakii. Bacteria were dried in controlled relative humidity atmospheres and then rehydrated using different methods. Our results showed that the survival of the three pathogens was strongly related to rehydration kinetics. Consequently, rehydration is an important step to consider during food safety assessment or during studies of dried foodborne pathogens. Also, it has to be considered with more attention in consumers’ homes during the preparation of food, like powdered infant formula, to avoid pathogens recovery. PMID:27494169
Recovery Estimation of Dried Foodborne Pathogens Is Directly Related to Rehydration Kinetics.
Directory of Open Access Journals (Sweden)
Emilie Lang
Full Text Available Drying is a common process which is used to preserve food products and technological microorganisms, but which is deleterious for the cells. The aim of this study is to differentiate the effects of drying alone from the effects of the successive and necessary rehydration. Rehydration of dried bacteria is a critical step already studied in starter culture but not for different kinetics and not for pathogens. In the present study, the influence of rehydration kinetics was investigated for three foodborne pathogens involved in neonatal diseases caused by the consumption of rehydrated milk powder: Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica serovar Senftenberg and Cronobacter sakazakii. Bacteria were dried in controlled relative humidity atmospheres and then rehydrated using different methods. Our results showed that the survival of the three pathogens was strongly related to rehydration kinetics. Consequently, rehydration is an important step to consider during food safety assessment or during studies of dried foodborne pathogens. Also, it has to be considered with more attention in consumers' homes during the preparation of food, like powdered infant formula, to avoid pathogens recovery.
Regulatory problems relating to energy in Hungary
International Nuclear Information System (INIS)
Remenyi, K.
2002-01-01
One of basic problems of the transition in the energy economy is, how far the process of liberalisation and privatisation could go, i.e. to what extent the control of state/government would be given up, and how the breakdown of the commanding positions of the government would be managed. The transition in the energy sector toward a market economy is characterised by restructuring the regulatory framework of the energy industry, changing the operational structure of the sector and profound reshaping of ownership structures of the enterprises. In Hungary the government, being convinced of the importance of the implementation of the market forces, in 1991 made the first step on the way of restructuring the energy sector in order to increase economic efficiency, to enable companies to react to market forces and to privatise them. Parallel and partly after the restructuring, a profound modification of legal and regulatory framework took place and finally a relatively large scale of privatisation has newly emerged, which will continue in future, too. The process of the energy sector liberalisation in Hungary has a stop and go character and the game is not over. The process can be characterised by institutional restructuring in the energy sector (coal, oil/gas, power ), which is the basic condition for market liberalisation and privatisation, and by the creation of an appropriate environment (regulatory framework, pricing policy, etc. ) for the smooth implementation of the liberation process(author)
Burgess, A. B. H.; Erler, A. R.; Shepherd, T. G.
2012-04-01
We present spectra, nonlinear interaction terms, and fluxes computed for horizontal wind fields from high-resolution meteorological analyses made available by ECMWF for the International Polar Year. Total kinetic energy spectra clearly show two spectral regimes: a steep spectrum at large scales and a shallow spectrum in the mesoscale. The spectral shallowing appears at ~200 hPa, and is due to decreasing rotational power with height, which results in the shallower divergent spectrum dominating in the mesoscale. The spectra we find are steeper than those observed in aircraft data and GCM simulations. Though the analyses resolve total spherical harmonic wavenumbers up to n = 721, effects of dissipation on the fluxes and spectra are visible starting at about n = 200. We find a weak forward energy cascade and a downscale enstrophy cascade in the mesoscale. Eddy-eddy nonlinear kinetic energy transfers reach maximum amplitudes at the tropopause, and decrease with height thereafter; zonal mean-eddy transfers dominate in the stratosphere. In addition, zonal anisotropy reaches a minimum at the tropopause. Combined with strong eddy-eddy interactions, this suggests flow in the tropopause region is very active and bears the greatest resemblance to isotropic turbulence. We find constant enstrophy flux over a broad range of wavenumbers around the tropopause and in the upper stratosphere. A relatively constant spectral enstrophy flux at the tropopause suggests a turbulent inertial range, and that the enstrophy flux is resolved. A main result of our work is its implications for explaining the shallow mesoscale spectrum observed in aircraft wind measurements, GCM studies, and now meteorological analyses. The strong divergent component in the shallow mesoscale spectrum indicates unbalanced flow, and nonlinear transfers decreasing quickly with height are characteristic of waves, not turbulence. Together with the downscale flux of energ y through the shallow spectral range, these
International Nuclear Information System (INIS)
Haranger, F.
2003-12-01
Ion beam irradiation of a solid can lead to the emission of neutral or ionized atoms, molecules or clusters from the surface. This comes as a result of the atomic motion in the vicinity of the surface, induced by the transfer of the projectile energy. Then, the study of the sputtering process appears as a means to get a better understanding of the excited matter state around the projectile trajectory. In the case of slow multicharged ions, a strong electronic excitation can be achieved by the projectile neutralization above the solid surface and / or its deexcitation below the surface. Parallel to this, the slowing down of such ions is essentially related to elastic collision with the target atoms. The study of the effect of the initial charge state of slow multicharged ions, in the sputtering process, has been carried out by measuring the absolute angular distributions of emission of uranium atoms from a uranium dioxide surface. The experiments have been performed in two steps. First, the emitted particles are collected onto a substrate during irradiation. Secondly, the surface of the collectors is analyzed by Rutherford Backscattering Spectrometry (RBS). This method allows the characterization of the emission of neutrals, which are the vast majority of the sputtered particles. The results obtained provide an access to the evolution of the sputtering process as a function of xenon projectile ions charge state. The measurements have been performed over a wide kinetic energy range, from 81 down to 1.5 keV. This allowed a clear separation of the contribution of the kinetic energy and initial projectile charge state to the sputtering phenomenon. (author)
Ixetl Garcia Gomez, Beatriz; Pallas Sanz, Enric; Candela Perez, Julio
2017-04-01
The near-inertial oscillations (NIOs), generated by the wind stress on the surface mixed layer, are the inertia gravity waves with the lowest frequency and the highest kinetic energy. NIOs are important because they drive vertical mixing in the interior ocean during wave breaking events. Although the interaction between NIOs and mesoscale eddies has been reported by several authors, these studies are mostly analytical and numerical, and only few observational studies have attempted to show the differences in near-inertial kinetic energy (KEi) between anticyclonic and cyclonic eddies. In this work the spatial structure of the KEi inside the mesoscale eddies is computed using daily satellite altimetry and observations of horizontal velocity from 23 moorings equipped with acoustic Doppler current profilers in the western Gulf of Mexico. Consistent to theory, the obtained four-year KEi-composites show two times more KEi inside the anticyclonic eddies than inside the cyclonic ones. The vertical and horizontal cross-sections of the KEi-composites show that the KEi is mainly located near to the surface of the cyclonic eddies (positive vorticity), whereas the KEi in anticyclonic eddies (negative vorticity) is maximum in the eddy's center near to the base of the eddy where the NIOs become more inertial, are trapped, and amplified. The mean vertical profiles show that the cyclonic eddies present a maximum of KEi near to the surface at 50, while the maximum of KEi in the anticyclonic eddies occurs between 900 and 1100 m. Inside anticyclonic eddies another two relative maximums are observed, one in the mixed layer and the second at 300 m. In contrast, the mean profile of KEi outside the mesoscale eddies has the maximum value at the surface ( 50 m), with high values of KEi in the first 200 m and negligible energy beneath that depth. A different mean distribution of the KEi is observed depending on the type of wind generator: tropical storms or unidirectional wind.
On the use of kinetic energy preserving DG-schemes for large eddy simulation
Flad, David; Gassner, Gregor
2017-12-01
-grid-scale models on top doesn't change much or in worst case decreases the fidelity even more. Finally, the core of this work is a novel LES strategy based on split form DG methods that are kinetic energy preserving. The scheme offers excellent stability with full control over the amount and shape of the added artificial dissipation. This premise is the main idea of the work and we will assess the LES capabilities of the novel split form DG approach when applied to shock-free, moderate Mach number turbulence. We will demonstrate that the novel DG LES strategy offers similar accuracy as the iLES methodology for well resolved cases, but strongly increases fidelity in case of more realistic coarse resolutions.
Directory of Open Access Journals (Sweden)
A. S. Laskin
2015-01-01
Full Text Available The article presents the results of numerical investigation of kinetic energy (KE loss and blading efficiency of the single-stage axial turbine under different operating conditions, characterized by the ratio u/C0. The calculations are performed by stationary (Stage method and nonstationary (Transient method methods using ANSYS CFX. The novelty of this work lies in the fact that the numerical simulation of steady and unsteady flows in a turbine stage is conducted, and the results are obtained to determine the loss of KE, both separately by the elements of the flow range and their total values, in the stage efficiency as well. The results obtained are compared with the calculated efficiency according to one-dimensional theory.To solve these problems was selected model of axial turbine stage with D/l = 13, blade profiles of rotor and stator of constant cross-section, similar to tested ones in inverted turbine when = 0.3. The degree of reactivity ρ = 0.27, the rotor speed was varied within the range 1000 ÷ 1800 rev/min.Results obtained allow us to draw the following conclusions:1. The level of averaged coefficients of total KE losses in the range of from 0.48 to 0.75 is from 18% to 21% when calculating by the Stage method and from 21% to 25% by the Transient one.2. The level of averaged coefficients of KE losses with the output speed of in the specified range is from 9% to 13%, and almost the same when in calculating by Stage and Transient methods.3. Levels of averaged coefficients of KE loss in blade tips (relative to the differential enthalpies per stage are changed in the range: from 4% to 3% (Stage and are stored to be equal to 5% (Transient; from 5% to 6% (Stage and from 6% to 8% (Transient.4. Coefficients of KE losses in blade tips GV and RB are higher in calculations of the model stage using the Transient method than the Stage one, respectively, by = 1.5 ÷ 2.5% and = 4 ÷ 5% of the absolute values. These are values to characterize the KE
Energy analyses and drying kinetics of chamomile leaves in microwave-convective dryer
Directory of Open Access Journals (Sweden)
Ali Motevali
2016-06-01
Full Text Available Drying characteristics and energy aspects as well as mathematical modeling of thin layer drying kinetics of chamomile in a microwave-convective dryer are reported in this article. Drying experiments were carried out at 8 microwave power levels (200–900 W, air temperature of 50 °C, and air velocity of 0.5 m/s. Increasing the microwave output power from 200 to 900 W, decreased the drying time from 40 to 10 min. The drying process took place in the falling rate period. The Midilli et al. model showed the best fit to the experimental drying data. Moisture diffusivity values increase with decreasing moisture content down to 1.70 (kg water kg−1 dry matter but decrease with a further decrease in moisture content from 1.72 to 0.96 (kg water kg−1 dry matter. The average values of Deff increased with microwave power from 5.46 to 39.63 × 10−8 (m2 s−1. Energy consumption increased and energy efficiency decreased with moisture content of chamomile samples. Average specific energy consumption, energy efficiency and energy loss varied in the range 18.93–28.15 MJ kg−1 water, 8.25–13.07% and 16.79–26.01 MJ kg−1 water, respectively, while the best energy results were obtained at 400 W, 50 °C and 0.5 m s−1.
Kinetic-energy distributions of O- produced by dissociative electron attachment to physisorbed O2
International Nuclear Information System (INIS)
Huels, M.A.; Parenteau, L.; Michaud, M.; Sanche, L.
1995-01-01
We report measurements of the kinetic energy (E k ) distributions of O - produced by low-energy electron impact (5.5--19.5 eV) on disordered multilayers of O 2 physisorbed on a polycrystalline Pt substrate. The results confirm that dissociative electron attachment (DEA) proceeds via the formation of the 2 Π u , 2 Σ g + (I), and 2 Σ x + (II) (x=g and/or u) states of O 2 -* . We also find evidence for an additional resonance, namely the 2 Σ u + (I), positioned at about 10 eV above the neutral ground state in the Franck-Condon region, and dissociating into O - +O( 3 P). The measurements suggest that the autodetachment lifetimes of the 2 Σ u + (I) and 2 Σ g + (II) states may be longer than previously suggested. It is also observed that the effects of electron energy loss (EEL) in the solid prior to DEA, O - scattering in the solid after dissociation, and the charge-induced polarization energy of the solid, broaden the E k distributions, shift them to lower anion energies, and result in additional structure in them. The effects of EEL on the desorption dynamics of O - are estimated from high-resolution electron-energy-loss spectra and excitation functions for losses in the vicinity of the Schumann-Runge continuum of the physisorbed O 2 molecules. We find indications for an enhancement of the optically forbidden X 3 Σ g - →A 3 Σ u + transition, and observe that the gas-phase Rydberg bands, for energy losses above 7 eV, are not distinguishable in the condensed phase
Law project relative to the energy markets
International Nuclear Information System (INIS)
2002-01-01
This document presents the law project relative to the energy markets. It aims to open the french gas market to the competition and defines the gas utilities obligations. The first part presents the main topics of the law: the natural gas distribution access, the natural gas sector regulation, the gas utilities, the natural gas transport and distribution, the underground storage, the control and penalties. The second part details the commission works concerning this law project. (A.L.B.)
International Nuclear Information System (INIS)
Montoya, M.; Rojas, J.; Saetone, E.
2007-01-01
The mass and kinetic energy distribution of nuclear fragments from thermal neutron-induced fission of 235 U(n th ,f) have been studied using a Monte-Carlo simulation. Besides reproducing the pronounced broadening in the standard deviation of the kinetic energy at the final fragment mass number around m = 109, our simulation also produces a second broadening around m = 125. These results are in good agreement with the experimental data obtained by Belhafaf et al. and other results on yield of mass. We conclude that the obtained results are a consequence of the characteristics of the neutron emission, the sharp variation in the primary fragment kinetic energy and mass yield curves. We show that because neutron emission is hazardous to make any conclusion on primary quantities distribution of fragments from experimental results on final quantities distributions
International Nuclear Information System (INIS)
Sandstrom, D.J.; Jessen, N.; Loewenstein, P.; Weirick, L.
1980-01-01
In early 1977 the National Materials Advisory Board, an operating unit in the Commission on Sociotechnical Systems of the National Research Council, NAS/NAE, formed a study committee on High Density Materials for Kinetic Energy Penetrators. The Specific objectives of the Committee were defined as follows. Assess the potential of two materials for use in kinetic energy penetrators, including such factors as: (a) properties (as applied to this application: strength, toughness, and dynamic behavior); (b) uniformity, reliability and reproducibility; (c) deterioration in storage; (d) production capability; (e) ecological impact; (f) quality assurance; (g) availability, and (h) cost. The Committee was divided into two Panels; one panel devoted to the study of tungsten alloys and the other devoted to the study of depleted uranium alloys for use in Kinetic energy penetrators. This report represents the findings and recommendation of the Panel on Uranium
Robertson, William C
2002-01-01
Confounded by kinetic energy? Suspect that teaching about simple machines isn t really so simple? Exasperated by electricity? If you fear the study of energy is beyond you, this entertaining book will do more than introduce you to the topic. It will help you actually understand it. At the book s heart are easy-to-grasp explanations of energy basics work, kinetic energy, potential energy, and the transformation of energy and energy as it relates to simple machines, heat energy, temperature, and heat transfer. Irreverent author Bill Robertson suggests activities that bring the basic concepts of energy to life with common household objects. Each chapter ends with a summary and an applications section that uses practical examples such as roller coasters and home heating systems to explain energy transformations and convection cells. The final chapter brings together key concepts in an easy-to-grasp explanation of how electricity is generated. Energy is the second book in the Stop Faking It! series published by NS...
Energy Technology Data Exchange (ETDEWEB)
Levy, Mel, E-mail: ayers@mcmaster.ca, E-mail: mlevy@tulane.edu [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Department of Physics, North Carolina A and T State University, Greensboro, North Carolina 27411 (United States); Department of Chemistry, Tulane University, New Orleans, Louisiana 70118 (United States); Anderson, James S. M.; Zadeh, Farnaz Heidar; Ayers, Paul W., E-mail: ayers@mcmaster.ca, E-mail: mlevy@tulane.edu [Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario (Canada)
2014-05-14
Properties of exact density functionals provide useful constraints for the development of new approximate functionals. This paper focuses on convex sums of ground-level densities. It is observed that the electronic kinetic energy of a convex sum of degenerate ground-level densities is equal to the convex sum of the kinetic energies of the individual degenerate densities. (The same type of relationship holds also for the electron-electron repulsion energy.) This extends a known property of the Levy-Valone Ensemble Constrained-Search and the Lieb Legendre-Transform refomulations of the Hohenberg-Kohn functional to the individual components of the functional. Moreover, we observe that the kinetic and electron-repulsion results also apply to densities with fractional electron number (even if there are no degeneracies), and we close with an analogous point-wise property involving the external potential. Examples where different degenerate states have different kinetic energy and electron-nuclear attraction energy are given; consequently, individual components of the ground state electronic energy can change abruptly when the molecular geometry changes. These discontinuities are predicted to be ubiquitous at conical intersections, complicating the development of universally applicable density-functional approximations.
Kinetic energy of solid and liquid para-hydrogen: a path integral Monte Carlo simulation
International Nuclear Information System (INIS)
Zoppi, M.; Neumann, M.
1992-01-01
The translational (center of mass) kinetic energy of solid and liquid para-hydrogen have been recently measured by means of Deep Inelastic Neutron Scattering. We have evaluated the same quantity, in similar thermodynamic conditions, by means of Path Integral Monte Carlo computer simulation, modelling the system as composed of a set of spherical molecules interacting through a pairwise additive Lennard-Jones potential. In spite of the crude approximations on the interaction potential, the agreement is excellent. The pressure was also computed by means of the same simulations. This quantity, compared with the equation of state for solid para-hydrogen given by Driessen and Silvera, gives an agreement of a lesser quality and a negative value for the liquid state. We attribute this discrepancy to the limitations of the Lennard-Jones potential. (orig.)
Electromagnetic response in kinetic energy driven cuprate superconductors: Linear response approach
International Nuclear Information System (INIS)
Krzyzosiak, Mateusz; Huang, Zheyu; Feng, Shiping; Gonczarek, Ryszard
2010-01-01
Within the framework of the kinetic energy driven superconductivity, the electromagnetic response in cuprate superconductors is studied in the linear response approach. The kernel of the response function is evaluated and employed to calculate the local magnetic field profile, the magnetic field penetration depth, and the superfluid density, based on the specular reflection model for a purely transverse vector potential. It is shown that the low temperature magnetic field profile follows an exponential decay at the surface, while the magnetic field penetration depth depends linearly on temperature, except for the strong deviation from the linear characteristics at extremely low temperatures. The superfluid density is found to decrease linearly with decreasing doping concentration in the underdoped regime. The problem of gauge invariance is addressed and an approximation for the dressed current vertex, which does not violate local charge conservation is proposed and discussed.
Interfacial mixing in high-energy-density matter with a multiphysics kinetic model
Haack, Jeffrey R.; Hauck, Cory D.; Murillo, Michael S.
2017-12-01
We have extended a recently developed multispecies, multitemperature Bhatnagar-Gross-Krook model [Haack et al., J. Stat. Phys. 168, 822 (2017), 10.1007/s10955-017-1824-9], to include multiphysics capabilities that enable modeling of a wider range of physical conditions. In terms of geometry, we have extended from the spatially homogeneous setting to one spatial dimension. In terms of the physics, we have included an atomic ionization model, accurate collision physics across coupling regimes, self-consistent electric fields, and degeneracy in the electronic screening. We apply the model to a warm dense matter scenario in which the ablator-fuel interface of an inertial confinement fusion target is heated, but for larger length and time scales and for much higher temperatures than can be simulated using molecular dynamics. Relative to molecular dynamics, the kinetic model greatly extends the temperature regime and the spatiotemporal scales over which we are able to model. In our numerical results we observe hydrogen from the ablator material jetting into the fuel during the early stages of the implosion and compare the relative size of various diffusion components (Fickean diffusion, electrodiffusion, and barodiffusion) that drive this process. We also examine kinetic effects, such as anisotropic distributions and velocity separation, in order to determine when this problem can be described with a hydrodynamic model.
Unified dark energy and dust dark matter dual to quadratic purely kinetic K-essence
International Nuclear Information System (INIS)
Guendelman, Eduardo; Nissimov, Emil; Pacheva, Svetlana
2016-01-01
We consider a modified gravity plus single scalar-field model, where the scalar Lagrangian couples symmetrically both to the standard Riemannian volume-form (spacetime integration measure density) given by the square root of the determinant of the Riemannian metric, as well as to another non-Riemannian volume-form in terms of an auxiliary maximal-rank antisymmetric tensor gauge field. As shown in a previous paper, the pertinent scalar-field dynamics provides an exact unified description of both dark energy via dynamical generation of a cosmological constant, and dark matter as a ''dust'' fluid with geodesic flow as a result of a hidden Noether symmetry. Here we extend the discussion by considering a non-trivial modification of the purely gravitational action in the form of f(R) = R -αR 2 generalized gravity. Upon deriving the corresponding ''Einstein-frame'' effective action of the latter modified gravity-scalar-field theory we find explicit duality (in the sense of weak versus strong coupling) between the original model of unified dynamical dark energy and dust fluid dark matter, on one hand, and a specific quadratic purely kinetic ''k-essence'' gravity-matter model with special dependence of its coupling constants on only two independent parameters, on the other hand. The canonical Hamiltonian treatment and Wheeler-DeWitt quantization of the dual purely kinetic ''k-essence'' gravity-matter model is also briefly discussed. (orig.)
Kinetic mean field theories: Results of energy constraint in maximizing entropy
Stell, G.; Karkheck, J.; Beijeren, H. van
1983-01-01
Structure of liquids and solids; crystallography Classical, semiclassical, and quantum theories of liquid structure Statistical theories of liquid structure - Kinetic and transport theory of fluids; physical properties of gases Kinetic and transport theory
Cars and Kinetic Energy--Some Simple Physics with Real-World Relevance
Parthasarathy, Raghuveer
2012-01-01
Understanding energy usage is crucial to understanding modern civilization, as well as many of the challenges it faces. Energy-related issues also offer real-world examples of important physical concepts, and as such have been the focus of several articles in "The Physics Teacher" in the past few decades (e.g., Refs. 1-5, noted further below).…
Cascade of kinetic energy and scalar variance in DC electrokinetic turbulence
Zhao, Wei; Wang, Guiren
2017-11-01
Turbulent flow can be generated by DC electrokinetic (EK) force based on the electric conductivity and permittivity variations in fluids, as have been demonstrated by Varshney et al (2016), where a -1.4 slope of velocity power spectrum is observed. Here, we theoretically found the scaling exponents of velocity and scalar structures in the electric-body-force (EBF) dominant subregion of DC EK turbulence were 2/5 (equivalent to the -7/5 slope of velocity power spectrum) and 4/5 respectively. The theory perfectly explains the experimental results of Varshney et al. (2016). Based on Kármán-Howarth equation with forcing terms, the energy cascade process of DC EK turbulence was also investigated. Depending on the electric Rayleigh number (Rae) , two different energy cascade processes may happen. When Rae is small, the kinetic energy cascades along inertial subregion and EBF dominant subregion in sequence, before it is dissipated by fluid viscosity. When Rae is sufficiently large, the inertial subregion may be absent with EBF dominant subregion left. This investigation is very important on understand EK turbulence, which could be widely existed in nature and applied in engineerings. The work was supported by NSFC (11672229), and NSF (CAREER CBET-0954977 and MRI CBET-1040227).
Dynamics of entropy perturbations in assisted dark energy with mixed kinetic terms
International Nuclear Information System (INIS)
Karwan, Khamphee
2011-01-01
We study dynamics of entropy perturbations in the two-field assisted dark energy model. Based on the scenario of assisted dark energy, in which one scalar field is subdominant compared with the other in the early epoch, we show that the entropy perturbations in this two-field system tend to be constant on large scales in the early epoch and hence survive until the present era for a generic evolution of both fields during the radiation and matter eras. This behaviour of the entropy perturbations is preserved even when the fields are coupled via kinetic interaction. Since, for assisted dark energy, the subdominant field in the early epoch becomes dominant at late time, the entropy perturbations can significantly influence the dynamics of density perturbations in the universe. Assuming correlations between the entropy and curvature perturbations, the entropy perturbations can enhance the integrated Sachs-Wolfe (ISW) effect if the signs of the contributions from entropy perturbations and curvature perturbations are opposite after the matter era, otherwise the ISW contribution is suppressed. For canonical scalar field the effect of entropy perturbations on ISW effect is small because the initial value of the entropy perturbations estimated during inflation cannot be sufficiently large. However, in the case of k-essence, the initial value of the entropy perturbations can be large enough to affect the ISW effect to leave a significant imprint on the CMB power spectrum
Ma, Fuying; Zeng, Yelin; Wang, Jinjin; Yang, Yang; Yang, Xuewei; Zhang, Xiaoyu
2013-01-01
Non-isothermal thermogravimetry/derivative thermogravimetry (TG/DTG) measurements are used to determine pyrolytic characteristics and kinetics of lignocellulose. TG/DTG experiments at different heating rates with corn stover pretreated with monocultures of Irpex lacteus CD2 and Auricularia polytricha AP and their cocultures were conducted. Heating rates had little effect on the pyrolysis process, but the peak of weight loss rate in the DTG curves shifted towards higher temperature with heating rate. The maximum weight loss of biopretreated samples was 1.25-fold higher than that of the control at the three heating rates, and the maximum weight loss rate of the co-culture pretreated samples was intermediate between that of the two mono-cultures. The activation energies of the co-culture pretreated samples were 16-72 kJ mol(-1) lower than that of the mono-culture at the conversion rate range from 10% to 60%. This suggests that co-culture pretreatment can decrease activation energy and accelerate pyrolysis reaction thus reducing energy consumption. Copyright © 2012 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Mads Jochumsen
2017-01-01
Full Text Available Detection of single-trial movement intentions from EEG is paramount for brain-computer interfacing in neurorehabilitation. These movement intentions contain task-related information and if this is decoded, the neurorehabilitation could potentially be optimized. The aim of this study was to classify single-trial movement intentions associated with two levels of force and speed and three different grasp types using EEG rhythms and components of the movement-related cortical potential (MRCP as features. The feature importance was used to estimate encoding of discriminative information. Two data sets were used. 29 healthy subjects executed and imagined different hand movements, while EEG was recorded over the contralateral sensorimotor cortex. The following features were extracted: delta, theta, mu/alpha, beta, and gamma rhythms, readiness potential, negative slope, and motor potential of the MRCP. Sequential forward selection was performed, and classification was performed using linear discriminant analysis and support vector machines. Limited classification accuracies were obtained from the EEG rhythms and MRCP-components: 0.48±0.05 (grasp types, 0.41±0.07 (kinetic profiles, motor execution, and 0.39±0.08 (kinetic profiles, motor imagination. Delta activity contributed the most but all features provided discriminative information. These findings suggest that information from the entire EEG spectrum is needed to discriminate between task-related parameters from single-trial movement intentions.
Preliminary results of total kinetic energy modelling for neutron-induced fission
International Nuclear Information System (INIS)
Visan, I.; Giubega, G.; Tudora, A.
2015-01-01
The total kinetic energy as a function of fission fragments mass TKE(A) is an important quantity entering in prompt emission calculations. The experimentally distributions of TKE(A) are referring to a limited number of fission systems and incident energies. In the present paper, a preliminary model for TKE calculation in neutron induced fission system is presented. The range of fission fragments is chosen as in the Point by Point treatment. The model needs as input only mass excesses and deformation parameters taken from available nuclear databases being based on the following approximations: total excitation energy of fully accelerated fission fragments TXE is calculated from energy balance of neutron-induced fission systems as sum of the total excitation energy at scission E*sciss and deformation energy Edef. The deformation energy at scission is given by minimizing the potential energy at the scission configuration. At the scission point, the fission system is described by two spheroidal fragments nearly touching by a pre-scission distance or neck caused by the nuclear forces between fragments. Therefore, the Columbian repulsion depending on neck and, consequently, on the fragments deformation at scission, is essentially in TKE determination. An approximation is made based on the fission modes. For the very symmetric fission, the dominant super long channel is characterized by long distance between fragments leading to low TKE values. Due to magic and double-magic shells closure, the dominant S1 fission mode for pairs with heavy fragment mass AH around 130-134 is characterized by spherical heavy fragment shape and easily deformed light fragment. The nearly spherical shape of the complementary fragments are characterized by minimum distance, and consequently to maximum TKE values. The results obtained for TKE(A) are in good agreement with existing experimental data for many neutron induced fission systems, e.g. ''2''3''3&apos
Ginsberg, Edw. S.
2018-02-01
The compatibility of the Newtonian formulation of mechanical energy and the transformation equations of Galilean relativity is demonstrated for three simple examples of motion treated in most introductory physics courses (free fall, a frictionless inclined plane, and a mass/spring system). Only elementary concepts and mathematics, accessible to students at that level, are used. Emphasis is on pedagogy and concepts related to the transformation properties of potential energy.
Bazant, Zdenek P; Caner, Ferhun C
2013-11-26
Although there exists a vast literature on the dynamic comminution or fragmentation of rocks, concrete, metals, and ceramics, none of the known models suffices for macroscopic dynamic finite element analysis. This paper outlines the basic idea of the macroscopic model. Unlike static fracture, in which the driving force is the release of strain energy, here the essential idea is that the driving force of comminution under high-rate compression is the release of the local kinetic energy of shear strain rate. The density of this energy at strain rates >1,000/s is found to exceed the maximum possible strain energy density by orders of magnitude, making the strain energy irrelevant. It is shown that particle size is proportional to the -2/3 power of the shear strain rate and the 2/3 power of the interface fracture energy or interface shear stress, and that the comminution process is macroscopically equivalent to an apparent shear viscosity that is proportional (at constant interface stress) to the -1/3 power of this rate. A dimensionless indicator of the comminution intensity is formulated. The theory was inspired by noting that the local kinetic energy of shear strain rate plays a role analogous to the local kinetic energy of eddies in turbulent flow.
Shah, Amisha D; Kim, Jae-Hong; Huang, Ching-Hua
2006-12-01
The potential release of carbadox (CDX), a commonly used antibacterial agent in swine husbandry, into water systems is of a concern due to its carcinogenic and genotoxic effects. Until this study, the reactivity of carbadox (possessing quinoxaline N,N'-dioxide and hydrazone moieties) toward aqueous chlorine has yetto be investigated in depth. Chemical reactivity, reaction kinetics, and transformation pathways of carbadox and structurally related compounds with free chlorine under typical water treatment conditions were determined. This study found that only CDX and desoxycarbadox (DCDX), a main metabolite of CDX with no ring N-oxide groups, react rapidly with free chlorine while other structurally related compounds including olaquindox, quindoxin, quinoxaline N-oxide, quinoxaline, and quinoline N-oxide do not. The reaction kinetics of CDX and DCDX with chlorine are highly pH dependent (e.g., the apparent second-order rate constant, kapp, for CDX ranges from 51.8 to 3.15 x 10(4) M(-1)s(-1) at pH 4-11). The high reactivity of CDX and DCDX to chlorine involves deprotonation of their hydrazone N-H moieties where initial chlorine attack results in a reactive intermediate that is further attacked by nucleophiles in the matrix to yield non-chlorinated, hydroxylated, and larger molecular weight byproducts. All of the CDX's byproducts retain their biologically active N-oxide groups, suggesting that they may remain as active antibacterial agents.
Nuclear energy: strategy of public relations
Energy Technology Data Exchange (ETDEWEB)
Timell, S [Swedish Power Association, Stockholm, Sweden
1981-02-21
A referendum was held in Sweden on 23rd March 1980, stimulated by the Three Mile Island accident in USA, to determine the future nuclear power development policy. The electricity supply background is that in 1980, 65% of power was hydro, 25% nuclear and 10% coal and oil. In terms of total power consumption, the country is heavily dependent on oil, which represents about 75%. The intensive public relations activity previous to the referendum is described, and this involved fact accumulation and assimilation, dissemination through various media, including brochures, displays, films and leaflets. In the political arena three lines developed: (1) (Conservatives); continue nuclear power, building at least 12 reactors, (2) (Social democrats and liberals); similar to (1), but more cautious, with emphasis on energy conservation, (3) (Centre parties and communists); no more nuclear power, and prevention of uranium extraction in Sweden. The voting was (1) 18.9%, (2) 39.1%, (3) 38.7%, (No dec of the most topical is concerned with the inventory of risks due to each industrial energy sector. This session was in two parts, the first devoted to problems specific to each source of energy including nuclear, the second to commo The extension to longer distances may be made with caution and to the satisfaction of the regulatory authority.
Directory of Open Access Journals (Sweden)
Nicola H. Perry
2016-10-01
Full Text Available Mixed conducting perovskite oxides and related structures serving as electrodes for electrochemical oxygen incorporation and evolution in solid oxide fuel and electrolysis cells, respectively, play a significant role in determining the cell efficiency and lifetime. Desired improvements in catalytic activity for rapid surface oxygen exchange, fast bulk transport (electronic and ionic, and thermo-chemo-mechanical stability of oxygen electrodes will require increased understanding of the impact of both bulk and surface chemistry on these properties. This review highlights selected work at the International Institute for Carbon-Neutral Energy Research (I2CNER, Kyushu University, set in the context of work in the broader community, aiming to characterize and understand relationships between bulk and surface composition and oxygen electrode performance. Insights into aspects of bulk point defect chemistry, electronic structure, crystal structure, and cation choice that impact carrier concentrations and mobilities, surface exchange kinetics, and chemical expansion coefficients are emerging. At the same time, an understanding of the relationship between bulk and surface chemistry is being developed that may assist design of electrodes with more robust surface chemistries, e.g., impurity tolerance or limited surface segregation. Ion scattering techniques (e.g., secondary ion mass spectrometry, SIMS, or low energy ion scattering spectroscopy, LEIS with high surface sensitivity and increasing lateral resolution are proving useful for measuring surface exchange kinetics, diffusivity, and corresponding outer monolayer chemistry of electrodes exposed to typical operating conditions. Beyond consideration of chemical composition, the use of strain and/or a high density of active interfaces also show promise for enhancing performance.
Buchhave, Preben; Velte, Clara M.
2017-08-01
We present a method for converting a time record of turbulent velocity measured at a point in a flow to a spatial velocity record consisting of consecutive convection elements. The spatial record allows computation of dynamic statistical moments such as turbulent kinetic wavenumber spectra and spatial structure functions in a way that completely bypasses the need for Taylor's hypothesis. The spatial statistics agree with the classical counterparts, such as the total kinetic energy spectrum, at least for spatial extents up to the Taylor microscale. The requirements for applying the method are access to the instantaneous velocity magnitude, in addition to the desired flow quantity, and a high temporal resolution in comparison to the relevant time scales of the flow. We map, without distortion and bias, notoriously difficult developing turbulent high intensity flows using three main aspects that distinguish these measurements from previous work in the field: (1) The measurements are conducted using laser Doppler anemometry and are therefore not contaminated by directional ambiguity (in contrast to, e.g., frequently employed hot-wire anemometers); (2) the measurement data are extracted using a correctly and transparently functioning processor and are analysed using methods derived from first principles to provide unbiased estimates of the velocity statistics; (3) the exact mapping proposed herein has been applied to the high turbulence intensity flows investigated to avoid the significant distortions caused by Taylor's hypothesis. The method is first confirmed to produce the correct statistics using computer simulations and later applied to measurements in some of the most difficult regions of a round turbulent jet—the non-equilibrium developing region and the outermost parts of the developed jet. The proposed mapping is successfully validated using corresponding directly measured spatial statistics in the fully developed jet, even in the difficult outer regions of
Two novel kinetic techniques for determining relative V/K values for alternate substrates
International Nuclear Information System (INIS)
Anderson, V.; Kannan, B.
1986-01-01
The equilibrium perturbation method of determining kinetic isotope effects has been extended to permit the accurate measurement of relative V/K values for alternate substrates. In the Enoyl-CoA hydratase reaction at pH 8.0 the V/K for trans-2-pentenoyl-CoA (5:1(2t)-CoA) less than 10% greater than V/K for crotonyl-CoA while at pH 4.6 V/K for 5:1(2t)-CoA is over twice the V/K for crotonyl-CoA. This change in the ratio of V/K values indicates that there must be a pKa in the V/K pH profile for 5:1(2t)-CoA that is not characteristic of the free enzyme, a simple interpretation being 5:1(2t)-CoA is a sticky substrate. The pseudoequilibrium perturbation method is inaccurate when the ratio of V/K values exceeds 3. A companion pseudoequilibrium method is introduced where the initial conditions are constrained to produce an initial velocity of zero, rather than requiring the initial and final concentrations of the chromophoric substrate to be identical. The ratio of V/K values is simply the ratio of the concentration of the perturbant molecule to the equilibrium concentration of the nonperturbing analogue. This method combines the advantages of both the equilibrium perturbation method and of initial steady state measurements. The kinetic mechanism of L-3-hydroxyacyl-CoA dehydrogenase, an enzyme whose severe substrate inhibition and small primary 2 H isotope effect have made routine kinetic studies impractical, has been investigated by this method
Maximizing kinetic energy transfer in one-dimensional many-body collisions
International Nuclear Information System (INIS)
Ricardo, Bernard; Lee, Paul
2015-01-01
The main problem discussed in this paper involves a simple one-dimensional two-body collision, in which the problem can be extended into a chain of one-dimensional many-body collisions. The result is quite interesting, as it provides us with a thorough mathematical understanding that will help in designing a chain system for maximum energy transfer for a range of collision types. In this paper, we will show that there is a way to improve the kinetic energy transfer between two masses, and the idea can be applied recursively. However, this method only works for a certain range of collision types, which is indicated by a range of coefficients of restitution. Although the concept of momentum, elastic and inelastic collision, as well as Newton’s laws, are taught in junior college physics, especially in Singapore schools, students in this level are not expected to be able to do this problem quantitatively, as it requires rigorous mathematics, including calculus. Nevertheless, this paper provides nice analytical steps that address some common misconceptions in students’ way of thinking about one-dimensional collisions. (paper)
Accurate core ionization potentials and photoelectron kinetic energies for light elements
Energy Technology Data Exchange (ETDEWEB)
Thomas, T D [Oregon State Univ., Corvallis; Shaw, Jr, R W
1974-01-01
By electron spectroscopy accurate values have been determined for the neon 1s ionization potential (870.312 +- .017 eV) and the neon Auger (/sup 1/D/sub 2/) kinetic energy (804.557 +- .017 eV). Using these together with the neon 2s ionization potential for calibration, 1s ionization potentials have been determined for CF/sub 4/ (C = 301.96, F = 695.57), CO/sub 2/ (C = 297.71, O = 541.32), N/sub 2/ (N = 409.93) and ionization potentials for Ar (2s = 326.37, 2p/sub /sup 3///sub 2// = 248.60, 2p/sub /sup 1///sub 2// = 250.70). These are known with an accuracy of 0.05 eV. The results are in good agreement with those of other measurements but have significantly smaller uncertainties. Comparison is made between experimental and theoretical ionization potentials. The value for neon is quite close to a recently reported theoretical value of 870.0 eV. The relativistic corrections for a cylindrical mirror analyzer, which are much smaller at low energies than would be expected from an approximate formula, are discussed.
Maximizing kinetic energy transfer in one-dimensional many-body collisions
Ricardo, Bernard; Lee, Paul
2015-03-01
The main problem discussed in this paper involves a simple one-dimensional two-body collision, in which the problem can be extended into a chain of one-dimensional many-body collisions. The result is quite interesting, as it provides us with a thorough mathematical understanding that will help in designing a chain system for maximum energy transfer for a range of collision types. In this paper, we will show that there is a way to improve the kinetic energy transfer between two masses, and the idea can be applied recursively. However, this method only works for a certain range of collision types, which is indicated by a range of coefficients of restitution. Although the concept of momentum, elastic and inelastic collision, as well as Newton’s laws, are taught in junior college physics, especially in Singapore schools, students in this level are not expected to be able to do this problem quantitatively, as it requires rigorous mathematics, including calculus. Nevertheless, this paper provides nice analytical steps that address some common misconceptions in students’ way of thinking about one-dimensional collisions.
Directory of Open Access Journals (Sweden)
S. T. Antipov
2013-01-01
Full Text Available Results of the conducted pilot researches of drying of fruits of black currant in the vacuum apparatus with microwave energy supply are presented. The new way of drying and installation for its implementation is offered. The influence of major factors on kinetics of drying and temperature of heating of black currant is studied.
David, P; Hartfiel, J.; Janszen, H.; Petitjean, C.; Reist, H.W.; Polikanov, S.M.; Konijn, J.; Laat, de C.T.A.M.; Taal, A.; Krogulski, T.; Johansson, T.; Tibell, G.; Achard van Enschut, d' J.F.M.
1987-01-01
Mass yield and total kinetic energy release (TKE) distributions of fragments from prompt and delayed muon induced fission, separately, have been measured for the isotopes235U,238U,237Np and242Pu. The distributions from prompt muon induced fission are compared with the corresponding distributions
International Nuclear Information System (INIS)
Montoya, M.; Rojas, J.; Lobato, I.
2010-01-01
The average of fragment kinetic energy (E-bar sign*) and the multiplicity of prompt neutrons (ν(bar sign)) as a function of fragment mass (m*), as well as the fragment mass yield (Y(m*)) from thermal neutron-induced fission of 239 Pu have been measured by Tsuchiya et al.. In that work the mass and kinetic energy are calculated from the measured kinetic energy of one fragment and the difference of time of flight of the two complementary fragments. However they do not present their results about the standard deviation σ E *(m*). In this work we have made a numerical simulation of that experiment which reproduces its results, assuming an initial distribution of the primary fragment kinetic energy (E(A)) with a constant value of the standard deviation as function of fragment mass (σ E (A)). As a result of the simulation we obtain the dependence σ E *(m*) which presents an enhancement between m* = 92 and m* = 110, and a peak at m* = 121.
Energy fluxes and their relations within energy plants
International Nuclear Information System (INIS)
Grazzini, Giuseppe; Milazzo, Adriano
2007-01-01
Analysing how energy is delivered from its primary sources to final users, it may be seen that the evolution of technology, driven by economic considerations, has mainly rewarded those systems that have intense energy fluxes through their main sections. On the other hand, renewable energy sources are prevented from being widespread by their low energy density. If a high energy flux is a recognized target for energy use, one may try to characterise the various devices encountered along the energy path according to the concentration obtained of the energy flow. In this way, apart from measuring the energy loss suffered within a given device, it can be decided if this loss is adequate with respect to the gain in terms of energy density
Energy Technology Data Exchange (ETDEWEB)
Han, Cheng; Hou, De-fu; Li, Jia-rong [Central China Normal University, Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Wuhan, Hubei (China); Jiang, Bing-feng [Hubei University for Nationalities, Center for Theoretical Physics and School of Sciences, Enshi, Hubei (China)
2017-10-15
The dielectric functions ε{sub L}, ε{sub T} of the quark-gluon plasma (QGP) are derived within the framework of the kinetic theory with BGK-type collisional kernel. The collision effect manifested by the collision rate is encoded in the dielectric functions. Based on the derived dielectric functions we study the collisional energy loss suffered by a fast parton traveling through the QGP. The numerical results show that the collision rate increases the energy loss. (orig.)
Relations between the kinetic equation and the Langevin models in two-phase flow modelling
International Nuclear Information System (INIS)
Minier, J.P.; Pozorski, J.
1997-05-01
The purpose of this paper is to discuss PDF and stochastic models which are used in two-phase flow modelling. The aim of the present analysis is essentially to try to determine relations and consistency between different models. It is first recalled that different approaches actually correspond to PDF models written either in terms of the process trajectories or in terms of the PDF itself. The main difference lies in the choice of the independent variables which are retained. Two particular models are studied, the Kinetic Equation and the Langevin Equation model. The latter uses a Langevin equation to model the fluid velocities seen along particle trajectories. The Langevin model is more general since it contains an additional variable. It is shown that, in certain cases, this variable can be summed up exactly to retrieve the Kinetic Equation model as a marginal PDF. A joint fluid and solid particle PDF which includes the characteristics of both phases is proposed at the end of the paper. (author)
Li, Xiaowei; Mei, Qingqing; Dai, Xiaohu; Ding, Guoji
2017-03-01
Thermogravimetric analysis, Gaussian-fit-peak model (GFPM), and distributed activation energy model (DAEM) were firstly used to explore the effect of anaerobic digestion on sequential pyrolysis kinetic of four organic solid wastes (OSW). Results showed that the OSW weight loss mainly occurred in the second pyrolysis stage relating to organic matter decomposition. Compared with raw substrate, the weight loss of corresponding digestate was lower in the range of 180-550°C, but was higher in 550-900°C. GFPM analysis revealed that organic components volatized at peak temperatures of 188-263, 373-401 and 420-462°C had a faster degradation rate than those at 274-327°C during anaerobic digestion. DAEM analysis showed that anaerobic digestion had discrepant effects on activation energy for four OSW pyrolysis, possibly because of their different organic composition. It requires further investigation for the special organic matter, i.e., protein-like and carbohydrate-like groups, to confirm the assumption. Copyright © 2016 Elsevier Ltd. All rights reserved.
Maximal Rashba-like spin splitting via kinetic-energy-coupled inversion-symmetry breaking
Sunko, Veronika; Rosner, H.; Kushwaha, P.; Khim, S.; Mazzola, F.; Bawden, L.; Clark, O. J.; Riley, J. M.; Kasinathan, D.; Haverkort, M. W.; Kim, T. K.; Hoesch, M.; Fujii, J.; Vobornik, I.; MacKenzie, A. P.; King, P. D. C.
2017-09-01
Engineering and enhancing the breaking of inversion symmetry in solids—that is, allowing electrons to differentiate between ‘up’ and ‘down’—is a key goal in condensed-matter physics and materials science because it can be used to stabilize states that are of fundamental interest and also have potential practical applications. Examples include improved ferroelectrics for memory devices and materials that host Majorana zero modes for quantum computing. Although inversion symmetry is naturally broken in several crystalline environments, such as at surfaces and interfaces, maximizing the influence of this effect on the electronic states of interest remains a challenge. Here we present a mechanism for realizing a much larger coupling of inversion-symmetry breaking to itinerant surface electrons than is typically achieved. The key element is a pronounced asymmetry of surface hopping energies—that is, a kinetic-energy-coupled inversion-symmetry breaking, the energy scale of which is a substantial fraction of the bandwidth. Using spin- and angle-resolved photoemission spectroscopy, we demonstrate that such a strong inversion-symmetry breaking, when combined with spin-orbit interactions, can mediate Rashba-like spin splittings that are much larger than would typically be expected. The energy scale of the inversion-symmetry breaking that we achieve is so large that the spin splitting in the CoO2- and RhO2-derived surface states of delafossite oxides becomes controlled by the full atomic spin-orbit coupling of the 3d and 4d transition metals, resulting in some of the largest known Rashba-like spin splittings. The core structural building blocks that facilitate the bandwidth-scaled inversion-symmetry breaking are common to numerous materials. Our findings therefore provide opportunities for creating spin-textured states and suggest routes to interfacial control of inversion-symmetry breaking in designer heterostructures of oxides and other material classes.
Francisco, Fabiane Lacerda; Saviano, Alessandro Morais; Almeida, Túlia de Souza Botelho; Lourenço, Felipe Rebello
2016-05-01
Microbiological assays are widely used to estimate the relative potencies of antibiotics in order to guarantee the efficacy, safety, and quality of drug products. Despite of the advantages of turbidimetric bioassays when compared to other methods, it has limitations concerning the linearity and range of the dose-response curve determination. Here, we proposed to use partial least squares (PLS) regression to solve these limitations and to improve the prediction of relative potencies of antibiotics. Kinetic-reading microplate turbidimetric bioassays for apramacyin and vancomycin were performed using Escherichia coli (ATCC 8739) and Bacillus subtilis (ATCC 6633), respectively. Microbial growths were measured as absorbance up to 180 and 300min for apramycin and vancomycin turbidimetric bioassays, respectively. Conventional dose-response curves (absorbances or area under the microbial growth curve vs. log of antibiotic concentration) showed significant regression, however there were significant deviation of linearity. Thus, they could not be used for relative potency estimations. PLS regression allowed us to construct a predictive model for estimating the relative potencies of apramycin and vancomycin without over-fitting and it improved the linear range of turbidimetric bioassay. In addition, PLS regression provided predictions of relative potencies equivalent to those obtained from agar diffusion official methods. Therefore, we conclude that PLS regression may be used to estimate the relative potencies of antibiotics with significant advantages when compared to conventional dose-response curve determination. Copyright © 2016 Elsevier B.V. All rights reserved.
Public Relations - 2003 Energy and Environment Calendar
International Nuclear Information System (INIS)
Novosel, N.; Valcic, I.
2003-01-01
Ministry of Economy in co-operation with the Ministry of Education and Sport, Croatian Electric Utility and Enconet International during the year 2002 realized the project of preparing the calendar for 2003 containing primary school pupils' paintings about energy and environment and additional information about preparedness in the Republic of Croatia in the case of nuclear accident and recommendations for acting. The calendar is primarily created for families living in the circle 25 km from the Nuclear Power Plant Krsko and will be distributed to all pupils of primary schools on that territory. Therefore the collecting of paintings was carried out between pupils from fifth to eight grades in those schools. Expert commission chose twelve best paintings from fifty-two collected and ceremonial promotion of the calendar was held in the Technical museum in Zagreb. This kind of project is only one example of public relations with the purpose of knowledge building about successful living together with energy technologies. In this text the course of the project of realizing the calendar will be presented with the special accent on content and purpose of the text about preparedness in the Republic of Croatia in the case of nuclear accident and recommendations for acting. (author)
International Nuclear Information System (INIS)
Sütterlin, Bernadette; Brunner, Thomas A.; Siegrist, Michael
2011-01-01
The present paper aims to identify and describe different types of energy consumers in a more comprehensive way than previous segmentation studies using cluster analysis. Energy consumers were segmented based on their energy-related behavioral characteristics. In addition to purchase- and curtailment-related energy-saving behavior, consumer classification was also based on acceptance of policy measures and energy-related psychosocial factors, so the used behavioral segmentation base was more comprehensive compared to other studies. Furthermore, differentiation between the energy-saving purchase of daily products, such as food, and of energy efficient appliances allowed a more differentiated characterization of the energy consumer segments. The cluster analysis revealed six energy consumer segments: the idealistic, the selfless inconsequent, the thrifty, the materialistic, the convenience-oriented indifferent, and the problem-aware well-being-oriented energy consumer. Findings emphasize that using a broader and more distinct behavioral base is crucial for an adequate and differentiated description of energy consumer types. The paper concludes by highlighting the most promising energy consumer segments and discussing possible segment-specific marketing and policy strategies. - Highlights: ► By applying a cluster-analytic approach, new energy consumer segments are identified. ► A comprehensive, differentiated description of the different energy consumer types is provided. ► A distinction between purchase of daily products and energy efficient appliances is essential. ► Behavioral variables are a more suitable base for segmentation than general characteristics.
Directory of Open Access Journals (Sweden)
Petra Popović
2002-12-01
Full Text Available Background. This study was conducted to assess whether pattern ERG is a sensitive test in evaluating the retinal function in patients with retinitis pigmentosa. We wanted to determine how pattern ERG, reflecting the activity of inner retinal layers, is related to other psychophysical tests such as perimetry and visual acuity.Methods. An analysis was performed on 50 eyes of 25 patients with typical rod-cone retinitis pigmentosa. The standard Snellen visual acuity was tested. Visual field sensitivity was measured with automated static perimetry (Octopus G2 program where mean defect was taken as an index of visual field loss. In kinetic perimetry (Goldmann the average radius of the visual field measured with target II/4 and V/4 was calculated. Transient pattern ERG and all five flash ERG responses were also measured according to ISCEV standards. Amplitudes of pattern ERG P50 and N95 waves were compared to results of visual acuity and visual field testing.Results. In our group of 25 RP patients with visual acuity ranging from 0.16 to 1.0, PERG responses were preserved much better than full field ERGs. 72% of them had still recordable PERG responses, while 48% had cone and only 32% maximal responses. Scotopic rod responses were extinguished in all eyes. The normalized amplitudes of the PERG responses were also much higher (43.5% than cone (22.5% or maximal responses (4.5%. A strong correlation of both P50 and N95 amplitudes with Octopus mean defect index was found. In kinetic perimetry the correlation with PERG amplitudes was also high, but it was better with II/4 than with V/4 target. Patients with high preserved ERG responses had good visual acuity. In all patients with visual acuity less than 0.4 both flash and pattern ERG responses were already absent.Conclusions. This study shows that pattern ERG is an objective and sensitive test in evaluating the functional visual loss in retinitis pigmentosa. Amplitudes of P50 and N95 responses are linearly
French energy research problems in relation to national energy goals
International Nuclear Information System (INIS)
Ferrari, A.
1984-01-01
There is a new view in energy planning: the new Government has firmly decided to enlarge the spectrum of energy technologies, to give more possibilities. Some new technologies if they reach a sufficient economic balance may be better than the ones used presently, and strict economic analysis shall be complemented by including external cost and taking into account the other considerations (political, social, etc.). The energy situation is serious and no technology should be dismissed: nuclear energy which with coal is one of the two sources of energy already abundant, cannot be discarded especially in a country like France, poor in fossil sources. France shall go on using nuclear energy and this means pursuing the development of the Fast Breeder Reactor Technology, because this is a unique insurance against possible future energy scarcity. Under strict nonproliferation conditions they shall also continue the effort to export nuclear units, using the expertise gained while implementing their own program
International Nuclear Information System (INIS)
Roney, A.; Frigon, C.; Larzilliere, M.
1999-01-01
The optical translational spectroscopy technique, based on the principles of fast ion beam laser spectroscopy (FIBLAS) and translational spectroscopy, allows the kinetic energies study of neutral fragments released through free dissociation of a neutral molecule. This method presents interesting features such as near-threshold energy measurements and selection of a specific dissociation limit. The fragments resulting from free dissociation (not induced) of neutral molecules, produced by charge exchange processes with a fast ion beam, are probed by laser radiation. Monitoring of the laser-induced fluorescence allows high-resolution spectra due to the kinematic compression of the velocity spread. Measurements of kinetic energies released to the second limit of dissociation H(1s) + H(2l) of H 2 are put forth and compared with those obtained by means of off-axis translational spectroscopy
Moc, Jerzy
2012-01-01
We report correlated ab initio calculations for the Al13H- cluster anion isomers, their kinetic stability and vertical detachment energies (VDEs). Of the two most energetically favored anion structures involving H atom in terminal and threefold bridged sites of the icosahedral Al13-, the higher energy ‘threefold bridged' isomer is shown to be of low kinetic stability. Our results are consistent with the recent photoelectron spectroscopy (PE) study of Grubisic et al. who observed two distinct Al13H- isomers, one of them identified as ‘metastable'. The VDE energies computed at the CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVDZ level for the ‘terminal' and ‘threefold bridged' Al13H- isomers of 3.21 and 2.32 eV are in good agreement with those determined in the PE study.
Scott, Robert B.
2010-01-01
We compare the total kinetic energy (TKE) in four global eddying ocean circulation simulations with a global dataset of over 5000, quality controlled, moored current meter records. At individual mooring sites, there was considerable scatter between models and observations that was greater than estimated statistical uncertainty. Averaging over all current meter records in various depth ranges, all four models had mean TKE within a factor of two of observations above 3500. m, and within a factor of three below 3500. m. With the exception of observations between 20 and 100. m, the models tended to straddle the observations. However, individual models had clear biases. The free running (no data assimilation) model biases were largest below 2000. m. Idealized simulations revealed that the parameterized bottom boundary layer tidal currents were not likely the source of the problem, but that reducing quadratic bottom drag coefficient may improve the fit with deep observations. Data assimilation clearly improved the model-observation comparison, especially below 2000. m, despite assimilated data existing mostly above this depth and only south of 47°N. Different diagnostics revealed different aspects of the comparison, though in general the models appeared to be in an eddying-regime with TKE that compared reasonably well with observations. © 2010 Elsevier Ltd.
Sato, Daiki; Saitoh, Hiroumi
This paper proposes a new control method for reducing fluctuation of power system frequency through smoothing active power output of wind farm. The proposal is based on the modulation of rotaional kinetic energy of variable speed wind power generators through power converters between permanent magnet synchronous generators (PMSG) and transmission lines. In this paper, the proposed control is called Fluctuation Absorption by Flywheel Characteristics control (FAFC). The FAFC can be easily implemented by adding wind farm output signal to Maximum Power Point Tracking control signal through a feedback control loop. In order to verify the effectiveness of the FAFC control, a simulation study was carried out. In the study, it was assumed that the wind farm consisting of PMSG type wind power generator and induction machine type wind power generaotors is connected with a power sysem. The results of the study show that the FAFC control is a useful method for reducing the impacts of wind farm output fluctuation on system frequency without additional devices such as secondary battery.
On the mean kinetic energy of the proton in strong hydrogen bonded systems
Energy Technology Data Exchange (ETDEWEB)
Finkelstein, Y. [Nuclear Research Center–Negev, Beer-Sheva 84190 (Israel); Moreh, R. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Shang, S. L.; Wang, Y.; Liu, Z. K. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Shchur, Ya. [Institute for Condensed Matter Physics, 1 Svientsitskii str., L’viv 79011 (Ukraine)
2016-02-07
The mean atomic kinetic energies of the proton, Ke(H), and of the deuteron, Ke(D), were calculated in moderate and strongly hydrogen bonded (HB) systems, such as the ferro-electric crystals of the KDP type (XH{sub 2}PO{sub 4}, X = K, Cs, Rb, Tl), the DKDP (XD{sub 2}PO{sub 4}, X = K, Cs, Rb) type, and the X{sub 3}H(SO{sub 4}){sub 2} superprotonic conductors (X = K, Rb). All calculations utilized the simulated partial phonon density of states, deduced from density functional theory based first-principle calculations and from empirical lattice dynamics simulations in which the Coulomb, short range, covalent, and van der Waals interactions were accounted for. The presently calculated Ke(H) values for the two systems were found to be in excellent agreement with published values obtained by deep inelastic neutron scattering measurements carried out using the VESUVIO instrument of the Rutherford Laboratory, UK. The Ke(H) values of the M{sub 3}H(SO{sub 4}){sub 2} compounds, in which the hydrogen bonds are centro-symmetric, are much lower than those of the KDP type crystals, in direct consistency with the oxygen-oxygen distance R{sub OO}, being a measure of the HB strength.
Observations of the turbulent kinetic energy dissipation rate in the upper central South China Sea
Liang, Chang-Rong; Chen, Gui-Ying; Shang, Xiao-Dong
2017-05-01
Measurements of the turbulent kinetic energy dissipation rate ( ɛ), velocity, temperature, and salinity were obtained for the upper ocean of the central South China Sea (14.5° N, 117.0° E) during an experimental campaign from May 11 to 13, 2010. Dissipation in the diurnal mixed layer showed a diurnal variability that was strongly affected by the surface buoyancy flux. Dissipation was enhanced ( ɛ ˜ 10-7 W kg-1) at night due to the convective mixing and was weakened ( ɛ ˜ 10-9 W kg-1) in daytime due to the stratification. Dissipation in the thermocline varied with time under the influence of internal waves. Shear from high-frequency internal waves (period ˜8 h) played an important role in enhancing the turbulent mixing in the thermocline. In the period of strong high-frequency internal waves, the shear from high-frequency internal waves became strong and the depth-averaged ɛ in the thermocline was elevated by almost one order of magnitude. Compared with the dissipation in the thermocline, dissipation below was weaker (the time-averaged ɛ ˜ 10-10 W kg-1). The observation indicates that the dissipation rates during the measurements can be parameterized by the MacKinnon-Gregg model that is widely used in the continental shelf but are not in agreement with the Gregg-Henyey model used for the open ocean.
Large-scale kinetic energy spectra from Eulerian analysis of EOLE wind data
Desbois, M.
1975-01-01
A data set of 56,000 winds determined from the horizontal displacements of EOLE balloons at the 200 mb level in the Southern Hemisphere during the period October 1971-February 1972 is utilized for the computation of planetary- and synoptic-scale kinetic energy space spectra. However, the random distribution of measurements in space and time presents some problems for the spectral analysis. Two different approaches are used, i.e., a harmonic analysis of daily wind values at equi-distant points obtained by space-time interpolation of the data, and a correlation method using the direct measurements. Both methods give similar results for small wavenumbers, but the second is more accurate for higher wavenumbers (k above or equal to 10). The spectra show a maximum at wavenumbers 5 and 6 due to baroclinic instability and then decrease for high wavenumbers up to wavenumber 35 (which is the limit of the analysis), according to the inverse power law k to the negative p, with p close to 3.
A spectral chart method for estimating the mean turbulent kinetic energy dissipation rate
Djenidi, L.; Antonia, R. A.
2012-10-01
We present an empirical but simple and practical spectral chart method for determining the mean turbulent kinetic energy dissipation rate DNS spectra, points to this scaling being also valid at small Reynolds numbers, provided effects due to inhomogeneities in the flow are negligible. The methods avoid the difficulty associated with estimating time or spatial derivatives of the velocity fluctuations. It also avoids using the second hypothesis of K41, which implies the existence of a -5/3 inertial subrange only when the Taylor microscale Reynods number R λ is sufficiently large. The method is in fact applied to the lower wavenumber end of the dissipative range thus avoiding most of the problems due to inadequate spatial resolution of the velocity sensors and noise associated with the higher wavenumber end of this range.The use of spectral data (30 ≤ R λ ≤ 400) in both passive and active grid turbulence, a turbulent mixing layer and the turbulent wake of a circular cylinder indicates that the method is robust and should lead to reliable estimates of < \\varepsilon rangle in flows or flow regions where the first similarity hypothesis should hold; this would exclude, for example, the region near a wall.
Kinetic energy of He atoms in liquid 4He-3He mixtures
International Nuclear Information System (INIS)
Senesi, R.; Andreani, C.; Fielding, A.L.; Mayers, J.; Stirling, W.G.
2003-01-01
Deep inelastic neutron scattering measurements on liquid 3 He- 4 He mixtures in the normal phase have been performed on the VESUVIO spectrometer at the ISIS pulsed neutron source at exchanged wave vectors of about q≅120.0 A -1 . The neutron Compton profiles J(y) of the mixtures were measured along the T=1.96 K isotherm for 3 He concentrations, x, ranging from 0.1 to 1.0 at saturated vapor pressures. Values of kinetic energies of 3 He and 4 He atoms as a function of x, (x), were extracted from the second moment of J(y). The present determinations of (x) confirm previous experimental findings for both isotopes and, in the case of 3 He, a substantial disagreement with theory is found. In particular (x) for the 3 He atoms is found to be independent of concentration yielding a value 3 (x=0.1)≅12 K, much lower than the value suggested by the most recent theoretical estimates of approximately 19 K
On the mean kinetic energy of the proton in strong hydrogen bonded systems
International Nuclear Information System (INIS)
Finkelstein, Y.; Moreh, R.; Shang, S. L.; Wang, Y.; Liu, Z. K.; Shchur, Ya.
2016-01-01
The mean atomic kinetic energies of the proton, Ke(H), and of the deuteron, Ke(D), were calculated in moderate and strongly hydrogen bonded (HB) systems, such as the ferro-electric crystals of the KDP type (XH 2 PO 4 , X = K, Cs, Rb, Tl), the DKDP (XD 2 PO 4 , X = K, Cs, Rb) type, and the X 3 H(SO 4 ) 2 superprotonic conductors (X = K, Rb). All calculations utilized the simulated partial phonon density of states, deduced from density functional theory based first-principle calculations and from empirical lattice dynamics simulations in which the Coulomb, short range, covalent, and van der Waals interactions were accounted for. The presently calculated Ke(H) values for the two systems were found to be in excellent agreement with published values obtained by deep inelastic neutron scattering measurements carried out using the VESUVIO instrument of the Rutherford Laboratory, UK. The Ke(H) values of the M 3 H(SO 4 ) 2 compounds, in which the hydrogen bonds are centro-symmetric, are much lower than those of the KDP type crystals, in direct consistency with the oxygen-oxygen distance R OO , being a measure of the HB strength
McCaffery, Anthony J.
2018-03-01
This study of near-resonant, vibration-vibration (V-V) gas-phase energy transfer in diatomic molecules uses the theoretical/computational method, of Marsh & McCaffery (Marsh & McCaffery 2002 J. Chem. Phys. 117, 503 (doi:10.1063/1.1489998)) The method uses the angular momentum (AM) theoretical formalism to compute quantum-state populations within the component molecules of large, non-equilibrium, gas mixtures as the component species proceed to equilibration. Computed quantum-state populations are displayed in a number of formats that reveal the detailed mechanism of the near-resonant V-V process. Further, the evolution of quantum-state populations, for each species present, may be followed as the number of collision cycles increases, displaying the kinetics of evolution for each quantum state of the ensemble's molecules. These features are illustrated for ensembles containing vibrationally excited N2 in H2, O2 and N2 initially in their ground states. This article is part of the theme issue `Modern theoretical chemistry'.
Energy resolution and efficiency of phonon-mediated kinetic inductance detectors for light detection
International Nuclear Information System (INIS)
Cardani, L.; Colantoni, I.; Coppolecchia, A.; Cruciani, A.; Vignati, M.; Bellini, F.; Casali, N.; Cosmelli, C.; Di Domizio, S.; Castellano, M. G.; Tomei, C.
2015-01-01
The development of sensitive cryogenic light detectors is of primary interest for bolometric experiments searching for rare events like dark matter interactions or neutrino-less double beta decay. Thanks to their good energy resolution and the natural multiplexed read-out, Kinetic Inductance Detectors (KIDs) are particularly suitable for this purpose. To efficiently couple KIDs-based light detectors to the large crystals used by the most advanced bolometric detectors, active surfaces of several cm 2 are needed. For this reason, we are developing phonon-mediated detectors. In this paper, we present the results obtained with a prototype consisting of four 40 nm thick aluminum resonators patterned on a 2 × 2 cm 2 silicon chip, and calibrated with optical pulses and X-rays. The detector features a noise resolution σ E = 154 ± 7 eV and an (18 ± 2)% efficiency
Non-additive non-interacting kinetic energy of rare gas dimers
Jiang, Kaili; Nafziger, Jonathan; Wasserman, Adam
2018-03-01
Approximations of the non-additive non-interacting kinetic energy (NAKE) as an explicit functional of the density are the basis of several electronic structure methods that provide improved computational efficiency over standard Kohn-Sham calculations. However, within most fragment-based formalisms, there is no unique exact NAKE, making it difficult to develop general, robust approximations for it. When adjustments are made to the embedding formalisms to guarantee uniqueness, approximate functionals may be more meaningfully compared to the exact unique NAKE. We use numerically accurate inversions to study the exact NAKE of several rare-gas dimers within partition density functional theory, a method that provides the uniqueness for the exact NAKE. We find that the NAKE decreases nearly exponentially with atomic separation for the rare-gas dimers. We compute the logarithmic derivative of the NAKE with respect to the bond length for our numerically accurate inversions as well as for several approximate NAKE functionals. We show that standard approximate NAKE functionals do not reproduce the correct behavior for this logarithmic derivative and propose two new NAKE functionals that do. The first of these is based on a re-parametrization of a conjoint Perdew-Burke-Ernzerhof (PBE) functional. The second is a simple, physically motivated non-decomposable NAKE functional that matches the asymptotic decay constant without fitting.
Energy resolution and efficiency of phonon-mediated kinetic inductance detectors for light detection
Energy Technology Data Exchange (ETDEWEB)
Cardani, L., E-mail: laura.cardani@roma1.infn.it [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Physics Department, Princeton University, Washington Road, 08544, Princeton, New Jersey (United States); Colantoni, I.; Coppolecchia, A. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Cruciani, A.; Vignati, M.; Bellini, F.; Casali, N.; Cosmelli, C. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN - Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Di Domizio, S. [Dipartimento di Fisica, Università degli Studi di Genova, Via Dodecaneso 33, 16146 Genova (Italy); INFN - Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Castellano, M. G. [Istituto di Fotonica e Nanotecnologie - CNR, Via Cineto Romano 42, 00156 Roma (Italy); Tomei, C. [INFN - Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy)
2015-08-31
The development of sensitive cryogenic light detectors is of primary interest for bolometric experiments searching for rare events like dark matter interactions or neutrino-less double beta decay. Thanks to their good energy resolution and the natural multiplexed read-out, Kinetic Inductance Detectors (KIDs) are particularly suitable for this purpose. To efficiently couple KIDs-based light detectors to the large crystals used by the most advanced bolometric detectors, active surfaces of several cm{sup 2} are needed. For this reason, we are developing phonon-mediated detectors. In this paper, we present the results obtained with a prototype consisting of four 40 nm thick aluminum resonators patterned on a 2 × 2 cm{sup 2} silicon chip, and calibrated with optical pulses and X-rays. The detector features a noise resolution σ{sub E} = 154 ± 7 eV and an (18 ± 2)% efficiency.
Mechanism of seasonal eddy kinetic energy variability in the eastern equatorial Pacific Ocean
Wang, Minyang; Du, Yan; Qiu, Bo; Cheng, Xuhua; Luo, Yiyong; Chen, Xiao; Feng, Ming
2017-04-01
Enhanced mesoscale eddy activities or tropical instability waves (TIWs) exist along the northern front of the cold tongue in the eastern equatorial Pacific Ocean. In this study, we investigate seasonal variability of eddy kinetic energy (EKE) over this region and its associated dynamic mechanism using a global, eddy-resolving ocean general circulation model (OGCM) simulation, the equatorial mooring data, and satellite altimeter observations. The seasonal-varying enhanced EKE signals are found to expand westward from 100°W in June to 180°W in December between 0°N and 6°N. This westward expansion in EKE is closely connected to the barotropically-baroclinically unstable zonal flows that are in thermal-wind balance with the seasonal-varying thermocline trough along 4°N. By adopting an 1½-layer reduced-gravity model, we confirm that the seasonal perturbation of the thermocline trough is dominated by the anticyclonic wind stress curl forcing, which develops due to southerly winds along 4°N from June to December.
Spatial structure of kinetic energy spectra in LES simulations of flow in an offshore wind farm
Fruh, Wolf-Gerrit; Creech, Angus
2017-04-01
The evolution of wind turbine and wind farm wakes was investigated numerically for the case of Lillgrund wind farm consisting of a tightly packed array of 48 turbines. The simulations for a number of wind directions at a free wind speed of just under the rated wind speed in a neutrally stable atmosphere were carried out using Large-Eddy Simulations with the adaptive Finite-Element CFD solver Fluidity. The results were interpolated from the irregularly spaced mesh nodes onto a regular grid with comparable spatial resolution at horizontal slices at various heights. To investigate the development of the wake as the flow evolves through the array, spectra of the kinetic energy in sections perpendicular to the wind directions within the wake and to the sides of the array were calculated. This paper will present the key features and spectral slopes of the flow as a function of downstream distance from the front turbine through and beyond the array. The main focus will be on the modification of the spectra as the flow crosses a row of turbines followed by its decay in the run-up to the next row, but we will also present to wake decay of the wind farm wake downstream of the array.
Cancio, Antonio C.; Redd, Jeremy J.
2017-03-01
The scaling of neutral atoms to large Z, combining periodicity with a gradual trend to homogeneity, is a fundamental probe of density functional theory, one that has driven recent advances in understanding both the kinetic and exchange-correlation energies. Although research focus is normally upon the scaling of integrated energies, insights can also be gained from energy densities. We visualise the scaling of the positive-definite kinetic energy density (KED) in closed-shell atoms, in comparison to invariant quantities based upon the gradient and Laplacian of the density. We notice a striking fit of the KED within the core of any atom to a gradient expansion using both the gradient and the Laplacian, appearing as an asymptotic limit around which the KED oscillates. The gradient expansion is qualitatively different from that derived from first principles for a slowly varying electron gas and is correlated with a nonzero Pauli contribution to the KED near the nucleus. We propose and explore orbital-free meta-GGA models for the kinetic energy to describe these features, with some success, but the effects of quantum oscillations in the inner shells of atoms make a complete parametrisation difficult. We discuss implications for improved orbital-free description of molecular properties.
International Nuclear Information System (INIS)
Hieke, Anne-Sophie Charlotte; Pillai, Suresh D.
2015-01-01
The effect of attenuating the energy of a 10 MeV electron beam on Salmonella inactivation kinetics was investigated. No statistically significant differences were observed between the D 10 values of either Salmonella 4,[5],12:i:- or a Salmonella cocktail (S. 4,[5],12:i:-, Salmonella Heidelberg, Salmonella Newport, Salmonella Typhimurium, Salmonella) when irradiated with either a non-attenuated 10 MeV eBeam or an attenuated 10 MeV eBeam (~2.9±0.22 MeV). The results show that attenuating the energy of a 10 MeV eBeam to achieve low doses does not affect the inactivation kinetics of Salmonella spp. when compared to direct 10 MeV eBeam irradiation. - Highlights: • 10 MeV eBeam energy was attenuated to 2.9±0.22 MeV using HDPE sheets. • Attenuation of eBeam energy does not affect the inactivation kinetics of Salmonella. • Microbial inactivation is independent of eBeam energy in the range of 3–10 MeV
International Nuclear Information System (INIS)
Pagava, T.A.
2002-01-01
n-Si crystals grown by the float-zone method with a phosphorus concentration of ∼6 x 10 13 cm -3 and irradiated with 2-MeV electrons and 25-MeV protons were studied. It is shown that the kinetics of the isochronous annealing of the A centers and divacancies (the annealing temperature and the rearrangement of radiation defects in the situation where the dissociation of one type of defects gives rise to more stable defects) depends in a complicated way on the energy, dose, and temperature of irradiation; i.e., this kinetics depends on the relation between the concentrations of various radiation defects and on the charge state of reacting primary radiation defects when they interact with each other, with impurity atoms, and with disordered regions. An increase in the concentration of divacancies in the temperature range of 180-210 deg. C is attributed to the dissociation of disordered regions
International Nuclear Information System (INIS)
Teraoka, Yuden; Yoshigoe, Akitaka
2001-01-01
The influence of translational kinetic energy of incident O 2 molecules for the passive oxidation process of partially-oxidized Si(001) surfaces has been studied by photoemission spectroscopy. The translational kinetic energy of O 2 molecules was controlled up to 3 eV by a supersonic seed beam technique using a high temperature nozzle. Two translational kinetic energy thresholds (1.0 eV and 2.6 eV) were found out in accordance with the first-principles calculation for the oxidation of clean surfaces. Si-2p photoemission spectra measured in representative translational kinetic energies revealed that the translational kinetic energy dependent oxidation of dimers and the second layer (subsurface) backbonds were caused by the direct dissociative chemisorption of O 2 molecules. Moreover, the difference in chemical bonds for oxygen atoms was found out to be as low and high binding energy components in O-1s photoemission spectra. Especially, the low binding energy component increased with increasing the translational kinetic energy that indicates the translational kinetic energy induced oxidation in backbonds. (author)
Jeong, Daniel; Anagnostopoulos, Petros V; Roldan-Alzate, Alejandro; Srinivasan, Shardha; Schiebler, Mark L; Wieben, Oliver; François, Christopher J
2015-05-01
Ventricular kinetic energy measurements may provide a novel imaging biomarker of declining ventricular efficiency in patients with repaired tetralogy of Fallot. Our purpose was to assess differences in ventricular kinetic energy with 4-dimensional flow magnetic resonance imaging between patients with repaired tetralogy of Fallot and healthy volunteers. Cardiac magnetic resonance, including 4-dimensional flow magnetic resonance imaging, was performed at rest in 10 subjects with repaired tetralogy of Fallot and 9 healthy volunteers using clinical 1.5T and 3T magnetic resonance imaging scanners. Right and left ventricular kinetic energy (KERV and KELV), main pulmonary artery flow (QMPA), and aortic flow (QAO) were quantified using 4-dimensional flow magnetic resonance imaging data. Right and left ventricular size and function were measured using standard cardiac magnetic resonance techniques. Differences in peak systolic KERV and KELV in addition to the QMPA/KERV and QAO/KELV ratios between groups were assessed. Kinetic energy indices were compared with conventional cardiac magnetic resonance parameters. Peak systolic KERV and KELV were higher in patients with repaired tetralogy of Fallot (6.06 ± 2.27 mJ and 3.55 ± 2.12 mJ, respectively) than in healthy volunteers (5.47 ± 2.52 mJ and 2.48 ± 0.75 mJ, respectively), but were not statistically significant (P = .65 and P = .47, respectively). The QMPA/KERV and QAO/KELV ratios were lower in patients with repaired tetralogy of Fallot (7.53 ± 5.37 mL/[cycle mJ] and 9.65 ± 6.61 mL/[cycle mJ], respectively) than in healthy volunteers (19.33 ± 18.52 mL/[cycle mJ] and 35.98 ± 7.66 mL/[cycle mJ], respectively; P tetralogy of Fallot. Quantification of ventricular kinetic energy in patients with repaired tetralogy of Fallot is a new observation. Future studies are needed to determine whether changes in ventricular kinetic energy can provide earlier evidence of ventricular dysfunction and guide future medical and
Nuclear energy: strategy of public relations
International Nuclear Information System (INIS)
Timell, S.
1981-01-01
A referendum was held in Sweden on 23rd March 1980, stimulated by the Three Mile Island accident in USA, to determine the future nuclear power development policy. The electricity supply background is that in 1980, 65% of power was hydro, 25% nuclear and 10% coal and oil. In terms of total power consumption, the country is heavily dependent on oil, which represents about 75%. The intensive public relations activity previous to the referendum is described, and this involved fact accumulation and assimilation, dissemination through various media, including brochures, displays, films and leaflets. In the political arena three lines developed: (1) (Conservatives); continue nuclear power, building at least 12 reactors, (2) (Social democrats and liberals); similar to (1), but more cautious, with emphasis on energy conservation, (3) (Centre parties and communists); no more nuclear power, and prevention of uranium extraction in Sweden. The voting was (1) 18.9%, (2) 39.1%, (3) 38.7%, (No decision) 3.3%. (G.C.)
Base Program on Energy Related Research
Energy Technology Data Exchange (ETDEWEB)
Western Research Institute
2008-06-30
The main objective of the Base Research Program was to conduct both fundamental and applied research that will assist industry in developing, deploying, and commercializing efficient, nonpolluting fossil energy technologies that can compete effectively in meeting the energy requirements of the Nation. In that regard, tasks proposed under the WRI research areas were aligned with DOE objectives of secure and reliable energy; clean power generation; development of hydrogen resources; energy efficiency and development of innovative fuels from low and no-cost sources. The goal of the Base Research Program was to develop innovative technology solutions that will: (1) Increase the production of United States energy resources--coal, natural gas, oil, and renewable energy resources; (2) Enhance the competitiveness of United States energy technologies in international markets and assist in technology transfer; (3) Reduce the nation's dependence on foreign energy supplies and strengthen both the United States and regional economies; and (4) Minimize environmental impacts of energy production and utilization. This report summarizes the accomplishments of the overall Base Program. This document represents a stand-alone Final Report for the entire Program. It should be noted that an interim report describing the Program achievements was prepared in 2003 covering the progress made under various tasks completed during the first five years of this Program.
Age-related differences in norepinephrine kinetics: Effect of posture and sodium-restricted diet
International Nuclear Information System (INIS)
Supiano, M.A.; Linares, O.A.; Smith, M.J.; Halter, J.B.
1990-01-01
We used compartmental analysis to study the influence of age on the kinetics of norepinephrine (NE) distribution and metabolism. Plasma NE and [3H]NE levels were measured in 10 young (age 19-33 yr) and 13 elderly (age 62-73 yr) subjects in the basal supine position, during upright posture, and after 1 wk of a sodium-restricted diet. We found that the basal supine release rate of NE into the extravascular compartment, which is the site of endogenous NE release (NE2), was significantly increased in the elderly group (young, 9.6 +/- 0.5; elderly, 12.3 +/- 0.8 nmol.min-1.m-2; means +/- SE; P = 0.016), providing direct evidence for an age-related increase in sympathetic nervous system (SNS) tone. Although upright posture led to a greater increase in plasma NE in the young (0.90 +/- 0.07 to 2.36 +/- 0.16 nM) than in the elderly (1.31 +/- 0.11 to 2.56 +/- 0.31 nM; age group-posture interaction, P = 0.02), the increase in NE2 was similar between the young (9.6 +/- 0.6 to 16.2 +/- 1.5 nmol.min-1.m-2) and the elderly (11.6 +/- 1.4 to 16.1 +/- 2.4 nmol.min-1.m-2; posture effect, P = 0.001; age group-posture interaction, P = 0.15). Thus the increase in SNS tone resulting from upright posture was similar in young and elderly subjects. Plasma NE levels increased similarly in both groups after a sodium-restricted diet (diet effect, P = 0.001; age group-diet interaction, P = 0.23). However, NE2 did not increase significantly in either group (diet effect, P = 0.26), suggesting that SNS tone did not increase after a sodium-restricted diet. Compartmental analysis provides a description of age-related differences in NE kinetics, including an age-related increase in the extravascular NE release rate
Goger, Brigitta; Rotach, Mathias W.; Gohm, Alexander; Fuhrer, Oliver; Stiperski, Ivana; Holtslag, Albert A. M.
2018-07-01
The correct simulation of the atmospheric boundary layer (ABL) is crucial for reliable weather forecasts in truly complex terrain. However, common assumptions for model parametrizations are only valid for horizontally homogeneous and flat terrain. Here, we evaluate the turbulence parametrization of the numerical weather prediction model COSMO with a horizontal grid spacing of Δ x = 1.1 km for the Inn Valley, Austria. The long-term, high-resolution turbulence measurements of the i-Box measurement sites provide a useful data pool of the ABL structure in the valley and on slopes. We focus on days and nights when ABL processes dominate and a thermally-driven circulation is present. Simulations are performed for case studies with both a one-dimensional turbulence parametrization, which only considers the vertical turbulent exchange, and a hybrid turbulence parametrization, also including horizontal shear production and advection in the budget of turbulence kinetic energy (TKE). We find a general underestimation of TKE by the model with the one-dimensional turbulence parametrization. In the simulations with the hybrid turbulence parametrization, the modelled TKE has a more realistic structure, especially in situations when the TKE production is dominated by shear related to the afternoon up-valley flow, and during nights, when a stable ABL is present. The model performance also improves for stations on the slopes. An estimation of the horizontal shear production from the observation network suggests that three-dimensional effects are a relevant part of TKE production in the valley.
Frost, W.; Harper, W. L.
1975-01-01
Flow over surface obstructions can produce significantly large wind shears such that adverse flying conditions can occur for aeronautical systems (helicopters, STOL vehicles, etc.). Atmospheric flow fields resulting from a semi-elliptical surface obstruction in an otherwise horizontally homogeneous statistically stationary flow are modelled with the boundary-layer/Boussinesq-approximation of the governing equation of fluid mechanics. The turbulence kinetic energy equation is used to determine the dissipative effects of turbulent shear on the mean flow. Iso-lines of turbulence kinetic energy and turbulence intensity are plotted in the plane of the flow and highlight regions of high turbulence intensity in the stagnation zone and sharp gradients in intensity along the transition from adverse to favourable pressure gradient. Discussion of the effects of the disturbed wind field in CTOL and STOL aircraft flight path and obstruction clearance standards is given. The results indicate that closer inspection of these presently recommended standards as influenced by wind over irregular terrains is required.
Gold, Kenneth; Cheng, Yung Sung; Holmes, Thomas D
2007-04-01
These tests were conducted to develop a database that could be used to assess risks to soldiers from exposure to aerosolized metallic particulates when the crew compartment of an Abrams tank is perforated by a kinetic energy penetrator. Quantitative data are reported for aerosols produced by kinetic energy penetrators containing tungsten, nickel, and cobalt. The following are addressed: (1) concentrations and rates of particle settling inside the vehicle, (2) particle size distribution, (3) inhalable and respirable particulates, (4) distribution of aerosol particles by mass, and (5) particle shapes. The scenario described in this report simulates a rare occurrence. The lessons learned, however, highlight a requirement for developing protocols for analyses of metals in body fluids and urine as soon as practical, and also for implementing targeted postdeployment medical surveillance programs that monitor both body burden for respired metals and pulmonary function.
Pyrolysis Characteristics and Kinetics of Phoenix Tree Residues as a Potential Energy
Directory of Open Access Journals (Sweden)
H. Li
2015-09-01
Full Text Available By using a thermogravimetric analyser under argon atmosphere, the pyrolysis process and the kinetic model of phoenix tree residues (the little stem, middle stem, and leaf at a 30 °C min−1 heating rate and the phoenix tree mix at three different heating rates (10 °C min−1, 30 °C min−1, and 50 °C min−1 were examined. The catalyst and the co-pyrolysis samples were at a 30 °C min−1 heating rate. The catalysts were Na2CO3, ZnCl2 and CaO in a mass fraction of 5 %. The experimental results revealed that the phoenix tree residues pyrolysis process consisted of three stages: dehydration stage, main pyrolysis stage, and the slow decomposition of residues. As the heating rate increased, the pyrolysis characteristic temperature of the phoenix tree grew, there was a backward-shift of the pyrolysis rate curve, and the mass loss rate gradually increased. The phoenix tree residues’ activation energy changed throughout the whole pyrolysis process, and the pyrolysis temperature ranges of the three main components (cellulose, hemicellulose, and lignin existed in overlapping phenomenon. As compared to the little stem, middle stem, and leaf, the phoenix tree mix was more likely to be pyrolysed under the same heating rate. Different catalysts had a different impact on the pyrolysis: ZnCl2 moved the start point of the reaction to the lower temperatures, but did not speed up the reaction; Na2CO3 speeded up the reaction without changing the start point of the reaction; CaO speeded up the reaction, moved the start point of the reaction to higher temperatures.
Constantin, Lucian A; Fabiano, Eduardo; Della Sala, Fabio
2017-09-12
Using the semiclassical neutral atom theory, we developed a modified fourth-order kinetic energy (KE) gradient expansion (GE4m) that keeps unchanged all the linear-response terms of the uniform electron gas and gives a significant improvement with respect to the known semilocal functionals for both large atoms and jellium surfaces. On the other hand, GE4m is not accurate for light atoms; thus, we modified the GE4m coefficients making them dependent on a novel ingredient, the reduced Hartree potential, recently introduced in the Journal of Chemical Physics 2016, 145, 084110, in the context of exchange functionals. The resulting KE gradient expansion functional, named uGE4m, belongs to the novel class of u-meta-generalized-gradient-approximations (uMGGA) whose members depend on the conventional ingredients (i.e., the reduced gradient and Laplacian of the density) as well as on the reduced Hartree potential. To test uGE4m, we defined an appropriate benchmark (including total KE and KE differences for atoms, molecules and jellium clusters) for gradient expansion functionals, that is, including only those systems which are mainly described by a slowly varying density regime. While most of the GGA and meta-GGA KE functionals (we tested 18 of them) are accurate for some properties and inaccurate for others, uGE4m shows a consistently good performance for all the properties considered. This represents a qualitative boost in the KE functional development and highlights the importance of the reduced Hartree potential for the construction of next-generation KE functionals.
SNG from coal: thermodynamic and kinetic constraints; use of nuclear energy
International Nuclear Information System (INIS)
Shapira, D.
1983-01-01
Part I contains an analysis of the thermodynamic constraints of converting coal to SNG. It is shown that the thermodynamic constraints that limit the thermal efficiency are not inherent, but are the result of design decisions, based on available technology, as well as on the kinetic properties of available catalysts. The latter, limits the yield of methane to that obtainable at global equilibrium over carbon in the presence of CO, H 2 , CO 2 and H 2 O. The equilibrium composition is shown to be independent of the thermodynamic properties of the char or coal fed. These limitations give the nonisothermal two-stage processes significant thermodynamic advantages. The analysis in part I results in suggesting directions for modifying present processes in order to obtain higher thermal efficiences. It also presents two-stage process schemes which may have significant advantages over present technology. As the methodology used for the thermodynamic analysis contains some novel elements, it should be of interest to the reaction engineer in general, and should be applicable to a wide range of catalytic and noncatalytic processes. Part II focuses on the use of nuclear energy in the production of synthetic fuel. Two processes for the production of hydrogen (which is used in coal-to-SNG processes) are analyzed and compared. The two processes are: 1) hydrogen from electrolysis of water using nuclear heat. 2) Hydrogen from steam reforming of methane using nuclear heat. The method used is differential economic analysis which focuses on evaluating the inherent advantages and disadvantages of the proposed technologies. Part II shows that the use of high temperature heat in production of hydrogen from coal is less attractive than the use of the same heat to generate electricity and split water into H 2 and O 2
A spectral chart method for estimating the mean turbulent kinetic energy dissipation rate
Energy Technology Data Exchange (ETDEWEB)
Djenidi, L.; Antonia, R.A. [The University of Newcastle, School of Engineering, Newcastle, NSW (Australia)
2012-10-15
We present an empirical but simple and practical spectral chart method for determining the mean turbulent kinetic energy dissipation rate left angle {epsilon}right angle in a variety of turbulent flows. The method relies on the validity of the first similarity hypothesis of Kolmogorov (C R (Doklady) Acad Sci R R SS, NS 30:301-305, 1941) (or K41) which implies that spectra of velocity fluctuations scale on the kinematic viscosity {nu} and left angle {epsilon}right angle at large Reynolds numbers. However, the evidence, based on the DNS spectra, points to this scaling being also valid at small Reynolds numbers, provided effects due to inhomogeneities in the flow are negligible. The methods avoid the difficulty associated with estimating time or spatial derivatives of the velocity fluctuations. It also avoids using the second hypothesis of K41, which implies the existence of a -5/3 inertial subrange only when the Taylor microscale Reynolds number R{sub {lambda}} is sufficiently large. The method is in fact applied to the lower wavenumber end of the dissipative range thus avoiding most of the problems due to inadequate spatial resolution of the velocity sensors and noise associated with the higher wavenumber end of this range.The use of spectral data (30 {<=} R{sub {lambda}}{<=} 400) in both passive and active grid turbulence, a turbulent mixing layer and the turbulent wake of a circular cylinder indicates that the method is robust and should lead to reliable estimates of left angle {epsilon}right angle in flows or flow regions where the first similarity hypothesis should hold; this would exclude, for example, the region near a wall. (orig.)
International Nuclear Information System (INIS)
Rentenier, A; Bordenave-Montesquieu, D; Moretto-Capelle, P; Bordenave-Montesquieu, A
2003-01-01
Multifragmentation and asymmetric fission (AF) of the C 60 molecule induced by H + , H 2 + , H 3 + and He + ions at medium collision energies (2-130 keV) are considered. Momenta and kinetic energies of C n + fragment ions (n = 1- 12) are deduced from an analysis of time-of-flight spectra. In multifragmentation processes, momenta are found to be approximately constant when n > 2, a behaviour which explains that the most probable kinetic energy, as well as the width of the kinetic energy distributions, is found to be inversely proportional to the fragment size n; both momenta and kinetic energies are independent of the velocity and nature of the projectile, and hence of the energy deposit. A specific study of the AF shows that the kinetic energies of C 2 + , C 4 + and C 6 + fragments are also independent of the collision velocity and projectile species; a quantitative agreement is found with values deduced from kinetic energy release measurements by another group in electron impact experiments, and the observed decrease when the mass of the light fragment increases is also reproduced. A quantitative comparison of AF and multifragmentation for the n = 2, 4 and 6 fragment ions shows that kinetic energies in AF exceed that in multifragmentation, a result which explains the oscillations observed when momenta or kinetic energies of fragments are plotted against the n-value. The AF yield is also found to scale with the energy deposit in the collision velocity range extending below the velocity at the maximum of the electronic stopping power; except for protons, it remains negligible with respect to multifragmentation as soon as the total energy deposit exceeds about 100 eV
International Nuclear Information System (INIS)
Kamrukov, A.S.; Kozlov, N.P.; Myshelov, E.P.; Protasov, Yu.S.
1981-01-01
Analysis of physical specific features of radiator where plasma heating is performed with tbermalization of directed kinetic energy of dense plasma flows accelerated electrodynamically up to hypersonic velocities during its shock deceleration, is given. It is shown that the plasma heating method considered has a number of principle advantages as compared with methods most disseminated now for generation of dense intensively radiating plasma (current heating exploding method) and suggests new possibilities for construction of selective high brightness radiat.ion sources of ultraviolet and far vacuum ultraviolet ranges of spectrum. Radiation gas dynamic processes of hypersonic plasma flow deceleration formed with magnetoplasma compressors have been experimentally investigated on their interaction with condenced matters in vacuum and basic thermodynamic parameters of shock compressed plasma have been determined. It is shown that the conversion process of kinetic energy of high-velocity plasma flows to radiation is accomplished at very high efficiency-integral luminescence of shock compressed plasma can reach approximately 90% of initial kinetic energy of flow [ru
Andreani, Carla; Romanelli, Giovanni; Senesi, Roberto
2016-06-16
This study presents the first direct and quantitative measurement of the nuclear momentum distribution anisotropy and the quantum kinetic energy tensor in stable and metastable (supercooled) water near its triple point, using deep inelastic neutron scattering (DINS). From the experimental spectra, accurate line shapes of the hydrogen momentum distributions are derived using an anisotropic Gaussian and a model-independent framework. The experimental results, benchmarked with those obtained for the solid phase, provide the state of the art directional values of the hydrogen mean kinetic energy in metastable water. The determinations of the direction kinetic energies in the supercooled phase, provide accurate and quantitative measurements of these dynamical observables in metastable and stable phases, that is, key insight in the physical mechanisms of the hydrogen quantum state in both disordered and polycrystalline systems. The remarkable findings of this study establish novel insight into further expand the capacity and accuracy of DINS investigations of the nuclear quantum effects in water and represent reference experimental values for theoretical investigations.
Directory of Open Access Journals (Sweden)
Anning Cheng
2010-02-01
Full Text Available Seven boundary-layer cloud cases are simulated with UCLA-LES (The University of California, Los Angeles – large eddy simulation model with different horizontal and vertical gridspacing to investigate how the results depend on gridspacing. Some variables are more sensitive to horizontal gridspacing, while others are more sensitive to vertical gridspacing, and still others are sensitive to both horizontal and vertical gridspacings with similar or opposite trends. For cloud-related variables having the opposite dependence on horizontal and vertical gridspacings, changing the gridspacing proportionally in both directions gives the appearance of convergence. In this study, we mainly discuss the impact of subgrid-scale (SGS kinetic energy (KE on the simulations with coarsening of horizontal and vertical gridspacings. A running-mean operator is used to separate the KE of the high-resolution benchmark simulations into that of resolved scales of coarse-resolution simulations and that of SGSs. The diagnosed SGS KE is compared with that parameterized by the Smagorinsky-Lilly SGS scheme at various gridspacings. It is found that the parameterized SGS KE for the coarse-resolution simulations is usually underestimated but the resolved KE is unrealistically large, compared to benchmark simulations. However, the sum of resolved and SGS KEs is about the same for simulations with various gridspacings. The partitioning of SGS and resolved heat and moisture transports is consistent with that of SGS and resolved KE, which means that the parameterized transports are underestimated but resolved-scale transports are overestimated. On the whole, energy shifts to large-scales as the horizontal gridspacing becomes coarse, hence the size of clouds and the resolved circulation increase, the clouds become more stratiform-like with an increase in cloud fraction, cloud liquid-water path and surface precipitation; when coarse vertical gridspacing is used, cloud sizes do not
Impact of the lipid bilayer on energy transfer kinetics in the photosynthetic protein LH2.
Ogren, John I; Tong, Ashley L; Gordon, Samuel C; Chenu, Aurélia; Lu, Yue; Blankenship, Robert E; Cao, Jianshu; Schlau-Cohen, Gabriela S
2018-03-28
Photosynthetic purple bacteria convert solar energy to chemical energy with near unity quantum efficiency. The light-harvesting process begins with absorption of solar energy by an antenna protein called Light-Harvesting Complex 2 (LH2). Energy is subsequently transferred within LH2 and then through a network of additional light-harvesting proteins to a central location, termed the reaction center, where charge separation occurs. The energy transfer dynamics of LH2 are highly sensitive to intermolecular distances and relative organizations. As a result, minor structural perturbations can cause significant changes in these dynamics. Previous experiments have primarily been performed in two ways. One uses non-native samples where LH2 is solubilized in detergent, which can alter protein structure. The other uses complex membranes that contain multiple proteins within a large lipid area, which make it difficult to identify and distinguish perturbations caused by protein-protein interactions and lipid-protein interactions. Here, we introduce the use of the biochemical platform of model membrane discs to study the energy transfer dynamics of photosynthetic light-harvesting complexes in a near-native environment. We incorporate a single LH2 from Rhodobacter sphaeroides into membrane discs that provide a spectroscopically amenable sample in an environment more physiological than detergent but less complex than traditional membranes. This provides a simplified system to understand an individual protein and how the lipid-protein interaction affects energy transfer dynamics. We compare the energy transfer rates of detergent-solubilized LH2 with those of LH2 in membrane discs using transient absorption spectroscopy and transient absorption anisotropy. For one key energy transfer step in LH2, we observe a 30% enhancement of the rate for LH2 in membrane discs compared to that in detergent. Based on experimental results and theoretical modeling, we attribute this difference to
Energy related design decisions deserve simulation approach
Hensen, J.L.M.
1994-01-01
Building energy consumption and indoor climate result from complex dynamic thermal interactions between outdoor environment, building structure, environmental control systems, and occupants. This reality is too complicated to be casted in simple expressions, rules or graphs. After a general overview
Jana, Subrata; Samal, Prasanjit
2018-01-01
The behaviors of the positive definite Kohn-Sham kinetic energy density near the origin and at the asymptotic region play a major role in designing meta-generalized gradient approximations (meta-GGAs) for exchange in low-dimensional quantum systems. It is shown that near the origin of the parabolic quantum dot, the Kohn-Sham kinetic energy differs from its von Weizsäcker counterpart due to the p orbital contributions, whereas in the asymptotic region, the difference between the above two kinetic energy densities goes as ˜ρ/(r ) r2 . All these behaviors have been explored using the two-dimensional isotropic quantum harmonic oscillator as a test case. Several meta-GGA ingredients are then studied by making use of the above findings. Also, the asymptotic conditions for the exchange energy density and the potential at the meta-GGA level are proposed using the corresponding behaviors of the two kinetic energy densities.
Exact relations for energy transfer in self-gravitating isothermal turbulence.
Banerjee, Supratik; Kritsuk, Alexei G
2017-11-01
Self-gravitating isothermal supersonic turbulence is analyzed in the asymptotic limit of large Reynolds numbers. Based on the inviscid invariance of total energy, an exact relation is derived for homogeneous (not necessarily isotropic) turbulence. A modified definition for the two-point energy correlation functions is used to comply with the requirement of detailed energy equipartition in the acoustic limit. In contrast to the previous relations (S. Galtier and S. Banerjee, Phys. Rev. Lett. 107, 134501 (2011)PRLTAO0031-900710.1103/PhysRevLett.107.134501; S. Banerjee and S. Galtier, Phys. Rev. E 87, 013019 (2013)PLEEE81539-375510.1103/PhysRevE.87.013019), the current exact relation shows that the pressure dilatation terms play practically no role in the energy cascade. Both the flux and source terms are written in terms of two-point differences. Sources enter the relation in a form of mixed second-order structure functions. Unlike the kinetic and thermodynamic potential energies, the gravitational contribution is absent from the flux term. An estimate shows that, for the isotropic case, the correlation between density and gravitational acceleration may play an important role in modifying the energy transfer in self-gravitating turbulence. The exact relation is also written in an alternative form in terms of two-point correlation functions, which is then used to describe scale-by-scale energy budget in spectral space.
International Nuclear Information System (INIS)
Del-Sorbo, Dario
2015-01-01
Hydrodynamic simulations in high-energy-density physics and inertial confinement fusion require a detailed description of energy fluxes. The leading mechanism is the electron transport, which can be a nonlocal phenomenon that needs to be described with quasistationary and simplified Fokker-Planck models in large scale hydrodynamic codes. My thesis is dedicated to the development of a new nonlocal transport model based on a fast-moving-particles collision operator and on a first moment Fokker-Planck equation, simplified with an entropic closure relation. Such a closure enables a better description of the electron distribution function in the limit of high anisotropies, where small scale electrostatic instabilities could be excited. This new model, so called M1, is successfully compared with the well known nonlocal electron transport model proposed by Schurtz, Nicolai and Busquet, using different collision operators, and with the reduced Fokker-Planck model, based on a small-anisotropies polynomial closure relation (P1). Several typical configurations of heat transport are considered. We show that the M1 entropic model may operate in two and three dimensions and is able to account for electron transport modifications in external magnetic fields. Moreover, our model enables to compute realistic electron distribution functions, which can be used for kinetic studies, as for the plasma stability in the transport zone. It is demonstrated that the electron energy transport may strongly modify damping of Langmuir and ion acoustic waves, while the simplified nonlocal transport models are not able to describe accurately the modifications of the distribution function and plasma wave damping. The structure of the M1 model allows to naturally take into account self-generated magnetic fields, which play a crucial role in multidimensional simulations. Moreover, magnetic fields could also be used for the focusing of energetic particles in alternative ignition schemes. The M1 model
Khryachkov, Vitaly; Goverdovskii, Andrei; Ketlerov, Vladimir; Mitrofanov, Vecheslav; Sergachev, Alexei
2018-03-01
Binary fission of 232Th and 238U induced by fast neutrons were under intent investigation in the IPPE during recent years. These measurements were performed with a twin ionization chamber with Frisch grids. Signals from the detector were digitized for further processing with a specially developed software. It results in information of kinetic energies, masses, directions and Bragg curves of registered fission fragments. Total statistics of a few million fission events were collected during each experiment. It was discovered that for several combinations of fission fragment masses their total kinetic energy was very close to total free energy of the fissioning system. The probability of such fission events for the fast neutron induced fission was found to be much higher than for spontaneous fission of 252Cf and thermal neutron induced fission of 235U. For experiments with 238U target the energy of incident neutrons were 5 MeV and 6.5 MeV. Close analysis of dependence of fission fragment distribution on compound nucleus excitation energy gave us some explanation of the phenomenon. It could be a process in highly excited compound nucleus which leads the fissioning system from the scission point into the fusion valley with high probability.
On kinetic Boltzmann equations and related hydrodynamic flows with dry viscosity
Directory of Open Access Journals (Sweden)
Nikolai N. Bogoliubov (Jr.
2007-01-01
Full Text Available A two-component particle model of Boltzmann-Vlasov type kinetic equations in the form of special nonlinear integro-differential hydrodynamic systems on an infinite-dimensional functional manifold is discussed. We show that such systems are naturally connected with the nonlinear kinetic Boltzmann-Vlasov equations for some one-dimensional particle flows with pointwise interaction potential between particles. A new type of hydrodynamic two-component Benney equations is constructed and their Hamiltonian structure is analyzed.
Low-Velocity Impact Wear Behavior of Ball-to-Flat Contact Under Constant Kinetic Energy
Wang, Zhang; Cai, Zhen-bing; Chen, Zhi-qiang; Sun, Yang; Zhu, Min-hao
2017-11-01
The impact tests were conducted on metallic materials with different bulk hardness and Young's moduli. Analysis of the dynamics response during the tribological process showed that the tested materials had similar energy absorption, where the peak contact force increased as the tests continued. Moreover, wear volume decreased with the increase in Young's modulus of metals, except for Cr with a relatively low hardness. Wear rate was gradually reduced to a steady stage with increasing cycles, which was attributed to the decrease in contact stress and work-hardening effect. The main wear mechanism of impact was characterized by delamination, and the specific surface degradation mechanisms were depending on the mechanical properties of materials. The absorbed energy was used to the propagation of micro-cracks in the subsurface instead of plastic deformation, when resistance of friction wear and plastic behavior was improved. Hence, both the hardness and Young's modulus played important roles in the impact wear of metallic materials.
Huang, Peisheng; Sanford, Thomas B.; Imberger, JöRg
2009-12-01
Heat and turbulent kinetic energy budgets of the ocean surface layer during the passage of Hurricane Frances were examined using a three-dimensional hydrodynamic model. In situ data obtained with the Electromagnetic-Autonomous Profiling Explorer (EM-APEX) floats were used to set up the initial conditions of the model simulation and to compare to the simulation results. The spatial heat budgets reveal that during the hurricane passage, not only the entrainment in the bottom of surface mixed layer but also the horizontal water advection were important factors determining the spatial pattern of sea surface temperature. At the free surface, the hurricane-brought precipitation contributed a negligible amount to the air-sea heat exchange, but the precipitation produced a negative buoyancy flux in the surface layer that overwhelmed the instability induced by the heat loss to the atmosphere. Integrated over the domain within 400 km of the hurricane eye on day 245.71 of 2004, the rate of heat anomaly in the surface water was estimated to be about 0.45 PW (1 PW = 1015 W), with about 20% (0.09 PW in total) of this was due to the heat exchange at the air-sea interface, and almost all the remainder (0.36 PW) was downward transported by oceanic vertical mixing. Shear production was the major source of turbulent kinetic energy amounting 88.5% of the source of turbulent kinetic energy, while the rest (11.5%) was attributed to the wind stirring at sea surface. The increase of ocean potential energy due to vertical mixing represented 7.3% of the energy deposited by wind stress.
Energy Technology Data Exchange (ETDEWEB)
Taillefert, Martial [Georgia Inst. of Technology, Atlanta, GA (United States); Van Cappellen, Philippe [Univ. of Waterloo, ON (Canada)
2016-11-14
Recent developments in the theoretical treatment of geomicrobial reaction processes have resulted in the formulation of kinetic models that directly link the rates of microbial respiration and growth to the corresponding thermodynamic driving forces. The overall objective of this project was to verify and calibrate these kinetic models for the microbial reduction of uranium(VI) in geochemical conditions that mimic as much as possible field conditions. The approach combined modeling of bacterial processes using new bioenergetic rate laws, laboratory experiments to determine the bioavailability of uranium during uranium bioreduction, evaluation of microbial growth yield under energy-limited conditions using bioreactor experiments, competition experiments between metabolic processes in environmentally relevant conditions, and model applications at the field scale. The new kinetic descriptions of microbial U(VI) and Fe(III) reduction should replace those currently used in reactive transport models that couple catabolic energy generation and growth of microbial populations to the rates of biogeochemical redox processes. The above work was carried out in collaboration between the groups of Taillefert (batch reactor experiments and reaction modeling) at Georgia Tech and Van Cappellen (retentostat experiments and reactive transport modeling) at University of Waterloo (Canada).
Wang, Lin-Na; Cai, Chen; Zhang, Yun-Hong
2017-09-14
Organic aerosols will likely form in semisolid, glassy, and high viscous state in the atmosphere, which show nonequilibrium kinetic characteristics at low relative humidity (RH) conditions. In this study, we applied optical tweezers to investigate the water transport in a sucrose/(NH 4 ) 2 SO 4 droplet with high organic to inorganic mole ratio (OIR). The characteristic time ratio between the droplet radius and the RH was used to describe the water mass transfer difference dependent on RH. For OIR greater than 1:1 in sucrose/(NH 4 ) 2 SO 4 droplets, the characteristic time ratio at low RH (∼60%). We also coupled vacuum FTIR spectrometer and a high-speed photography to study the efflorescence process in sucrose/(NH 4 ) 2 SO 4 droplets with low OIR. The crystalline fraction of (NH 4 ) 2 SO 4 was used to understand efflorescence behavior when the RH was linearly decreasing with a velocity of 1.2% RH min -1 . Because of suppression of (NH 4 ) 2 SO 4 nucleation by addition of sucrose, the efflorescence relative humidity (ERH) of (NH 4 ) 2 SO 4 decrease from the range of ∼48.2% to ∼36.1% for pure (NH 4 ) 2 SO 4 droplets to from ∼44.7% to ∼25.4%, from ∼43.2% to ∼21.2%, and from ∼41.7% to ∼21.1% for the mixed droplets with OIR of 1:4, 1:3, and 1:2, respectively. No crystallization was observed when the OIR is higher than 1:1. Suppression of (NH 4 ) 2 SO 4 crystal growth was also observed under high viscous sucrose/(NH 4 ) 2 SO 4 droplets at lower RH.
Huanbutta, Kampanart; Sriamornsak, Pornsak; Limmatvapirat, Sontaya; Luangtana-anan, Manee; Yoshihashi, Yasuo; Yonemochi, Etsuo; Terada, Katsuhide; Nunthanid, Jurairat
2011-02-01
Magnetic resonance imaging (MRI) was used to assess in situ swelling behaviors of spray-dried chitosan acetate (CSA) in 0.1N HCl, pH 6.8 and pH 5.0 Tris-HCl buffers. The in vitro drug releases from CSA matrix tablets containing the model drugs, diclofenac sodium and theophylline were investigated in all media using USP-4 apparatus. The effect of chitosan molecular weight, especially in pH 6.8 Tris-HCl, was also studied. In 0.1N HCl, the drug release from the matrix tablets was the lowest in relation to the highest swelling of CSA. The swelling kinetics in Tris-HCl buffers are Fickian diffusion according to their best fit to Higuchi's model as well as the drug release kinetics in all the media. The high swelling rate (k(s)(')) was found to delay the drug release rate (k'). The linear relationship between the swelling and fractions of drug release in Tris-HCl buffers was observed, indicating an important role of the swelling on controlling the drug release mechanism. Additionally, CSA of 200 and 800 kDa chitosan did not swell in pH 6.8 Tris-HCl but disintegrated into fractions, and the drug release from the matrix tablets was the highest. Copyright © 2010 Elsevier B.V. All rights reserved.
Volumetric formulation for a class of kinetic models with energy conservation.
Sbragaglia, M; Sugiyama, K
2010-10-01
We analyze a volumetric formulation of lattice Boltzmann for compressible thermal fluid flows. The velocity set is chosen with the desired accuracy, based on the Gauss-Hermite quadrature procedure, and tested against controlled problems in bounded and unbounded fluids. The method allows the simulation of thermohydrodyamical problems without the need to preserve the exact space-filling nature of the velocity set, but still ensuring the exact conservation laws for density, momentum, and energy. Issues related to boundary condition problems and improvements based on grid refinement are also investigated.
Bisetti, Fabrizio; El Morsli, Mbark
2014-01-01
The effects of an electric field on the collision rates, energy exchanges and transport properties of electrons in premixed flames are investigated via solutions to the Boltzmann kinetic equation. The case of high electric field strength, which
International Nuclear Information System (INIS)
Dai, Zuyang; Gao, Shuming; Wang, Jia; Mo, Yuxiang
2014-01-01
The torsional energy levels of CH 3 OH + , CH 3 OD + , and CD 3 OD + have been determined for the first time using one-photon zero kinetic energy photoelectron spectroscopy. The adiabatic ionization energies for CH 3 OH, CH 3 OD, and CD 3 OD are determined as 10.8396, 10.8455, and 10.8732 eV with uncertainties of 0.0005 eV, respectively. Theoretical calculations have also been performed to obtain the torsional energy levels for the three isotopologues using a one-dimensional model with approximate zero-point energy corrections of the torsional potential energy curves. The calculated values are in good agreement with the experimental data. The barrier height of the torsional potential energy without zero-point energy correction was calculated as 157 cm −1 , which is about half of that of the neutral (340 cm −1 ). The calculations showed that the cation has eclipsed conformation at the energy minimum and staggered one at the saddle point, which is the opposite of what is observed in the neutral molecule. The fundamental C–O stretch vibrational energy level for CD 3 OD + has also been determined. The energy levels for the combinational excitation of the torsional vibration and the fundamental C–O stretch vibration indicate a strong torsion-vibration coupling
Dai, Zuyang; Gao, Shuming; Wang, Jia; Mo, Yuxiang
2014-10-14
The torsional energy levels of CH3OH(+), CH3OD(+), and CD3OD(+) have been determined for the first time using one-photon zero kinetic energy photoelectron spectroscopy. The adiabatic ionization energies for CH3OH, CH3OD, and CD3OD are determined as 10.8396, 10.8455, and 10.8732 eV with uncertainties of 0.0005 eV, respectively. Theoretical calculations have also been performed to obtain the torsional energy levels for the three isotopologues using a one-dimensional model with approximate zero-point energy corrections of the torsional potential energy curves. The calculated values are in good agreement with the experimental data. The barrier height of the torsional potential energy without zero-point energy correction was calculated as 157 cm(-1), which is about half of that of the neutral (340 cm(-1)). The calculations showed that the cation has eclipsed conformation at the energy minimum and staggered one at the saddle point, which is the opposite of what is observed in the neutral molecule. The fundamental C-O stretch vibrational energy level for CD3OD(+) has also been determined. The energy levels for the combinational excitation of the torsional vibration and the fundamental C-O stretch vibration indicate a strong torsion-vibration coupling.
2010-10-01
... environment, energy and water efficiency, renewable energy technologies, occupational safety, and drug-free workplace. 952.223 Section 952.223 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CLAUSES AND... related to environment, energy and water efficiency, renewable energy technologies, occupational safety...
Wang, Jun; Qiao, Zhiqiang; Yang, Yuntao; Shen, Jinpeng; Long, Zhang; Li, Zhaoqian; Cui, Xudong; Yang, Guangcheng
2016-01-04
The energy performance of solid energetic materials (Al, Mg, etc.) is typically restricted by a natural passivation layer and the diffusion-limited kinetics between the oxidizer and the metal. In this work, we use polytetrafluoroethylene (PTFE) as the fluorine carrier and the shielding layer to construct a new type of nano-Al based fuels. The PTFE shell not only prevents nano-Al layers from oxidation, but also assists in enhancing the reaction kinetics, greatly improving the stability and reactivity of fuels. An in situ chemical vapor deposition combined with the electrical explosion of wires (EEW) method is used to fabricate core-shell nanostructures. Studies show that by controlling the stoichiometric ratio of the precursors, the morphology of the PTFE shell and the energy performance can be easily tuned. The resultant composites exhibit superior energy output characters than that of their physically mixed Al/PTFE counterparts. This synthetic strategy might provide a general approach to prepare other high-energy fuels (Mg, Si). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Mass and kinetic-energy distributions of fragments formed in the heavy-ion-induced fission of 208Po
International Nuclear Information System (INIS)
Cuninghame, J.G.; Goodall, J.A.B.
1980-01-01
Fission fragments following the decay of a 208 Po compound nucleus have been observed by using radiochemical and particle-counting techniques. The (α+ 204 Pb), ( 12 C+ 196 Pt) and ( 16 O+ 192 Os) reactions were studied at two or three bombarding energies, covering overlapping ranges of excitation energies. - Radiochemical separations of As, Br, Y, Nb, Tc, Ag, Sb and I isotopes were made from catcher foils sandwiching isotopic targets, and their isotopic yield distributions determined. The distributions are used to estimate the average number of neutrons associated with each fission event, including neutrons emitted before and after fission. - Prompt coincidence measurements of fragments are used to derive the overall mass and kinetic-energy distributions of primary fragments, taking into account the effects of pre- and post-fission neutron emission. The mass distributions are well fitted by the statistical theory, at a temperature corresponding to an excitation about 10 MeV above that at the saddle point. No evidence is found for an increase of kinetic-energy with increasing angular momentum of the compound nucleus. (author)
The relation between energy - ecology - economy
International Nuclear Information System (INIS)
Horn, J.
1977-01-01
In North America and Western Europe, supporters of zero growth think that economy and energy, on the one hand, and an intact ecology, on the other, are opposites or opposing tendencies which cannot go hand in hand. These people also contest the claim that there is a linear correlation between a developing ecology and technology and increased energy consumption. The author thinks that the above basic assumptions are wrong and not in agreement with either the laws of evolution of the geosphere or with the necessities of the present political and economic situation. Giving an outline of the history of evolution and the present situation, especially in the developing countries, he shows that there is a linear, self-strengthening correlation between economic growth and capital-intensive technological innovation on the one hand and environmental improvement on the other. (orig./GG) [de
Quantum vacuum energy in general relativity
Energy Technology Data Exchange (ETDEWEB)
Henke, Christian [University of Technology at Clausthal, Department of Mathematics, Clausthal-Zellerfeld (Germany)
2018-02-15
The paper deals with the scale discrepancy between the observed vacuum energy in cosmology and the theoretical quantum vacuum energy (cosmological constant problem). Here, we demonstrate that Einstein's equation and an analogy to particle physics leads to the first physical justification of the so-called fine-tuning problem. This fine-tuning could be automatically satisfied with the variable cosmological term Λ(a) = Λ{sub 0} + Λ{sub 1}a{sup -(4-ε)}, 0 < ε << 1, where a is the scale factor. As a side effect of our solution of the cosmological constant problem, the dynamical part of the cosmological term generates an attractive force and solves the missing mass problem of dark matter. (orig.)
Directory of Open Access Journals (Sweden)
R. C. Sullivan
2004-01-01
Full Text Available The room temperature kinetics of gas-phase ozone loss via heterogeneous interactions with thin alumina films has been studied in real-time using 254nm absorption spectroscopy to monitor ozone concentrations. The films were prepared from dispersions of fine alumina powder in methanol and their surface areas were determined by an in situ procedure using adsorption of krypton at 77K. The alumina was found to lose reactivity with increasing ozone exposure. However, some of the lost reactivity could be recovered over timescales of days in an environment free of water, ozone and carbon dioxide. From multiple exposures of ozone to the same film, it was found that the number of active sites is large, greater than 1.4x1014 active sites per cm2 of surface area or comparable to the total number of surface sites. The films maintain some reactivity at this point, which is consistent with there being some degree of active site regeneration during the experiment and with ozone loss being catalytic to some degree. The initial uptake coefficients on fresh films were found to be inversely dependent on the ozone concentration, varying from roughly 10-6 for ozone concentrations of 1014 molecules/cm3 to 10-5 at 1013 molecules/cm3. The initial uptake coefficients were not dependent on the relative humidity, up to 75%, within the precision of the experiment. The reaction mechanism is discussed, as well as the implications these results have for assessing the effect of mineral dust on atmospheric oxidant levels.
International Nuclear Information System (INIS)
Vlahostergios, Z.; Yakinthos, K.; Goulas, A.
2009-01-01
We present an effort to model the separation-induced transition on a flat plate with a semi-circular leading edge, using a cubic non-linear eddy-viscosity model combined with the laminar kinetic energy. A non-linear model, compared to a linear one, has the advantage to resolve the anisotropic behavior of the Reynolds-stresses in the near-wall region and it provides a more accurate expression for the generation of turbulence in the transport equation of the turbulence kinetic energy. Although in its original formulation the model is not able to accurately predict the separation-induced transition, the inclusion of the laminar kinetic energy increases its accuracy. The adoption of the laminar kinetic energy by the non-linear model is presented in detail, together with some additional modifications required for the adaption of the laminar kinetic energy into the basic concepts of the non-linear eddy-viscosity model. The computational results using the proposed combined model are shown together with the ones obtained using an isotropic linear eddy-viscosity model, which adopts also the laminar kinetic energy concept and in comparison with the existing experimental data.
Keynotes in energy-related catalysis
Kaliaguine, S
2011-01-01
Catalysis by solid acids, which includes (modified) zeolites, is of special relevance to energy applications. Acid catalysis is highly important in modern petroleum refining operations - large-scale processes such as fluid catalytic cracking, catalytic reforming, alkylation and olefin oligomerization rely on the transformation of hydrocarbons by acid catalysts. (Modified) zeolites are therefore essential for the improvement of existing processes and for technical innovations in the conversion of crude. There can be little doubt that zeolite-based catalysts will play a major role in the futu
International Nuclear Information System (INIS)
Lucas, F.J.M.; Alvarez, J.G.; Sanchis, S.E.; Munoz, B.C.
1986-01-01
As sup(99m)Tc-Ca phytate is an important radiopharmaceutical and its colloidal nature presents problems, we investigated some of them. This work describes the study of the colloidal behaviour of the calcium phytate colloid in terms of its formation, stability and kinetics of flocculation. The study of spontaneous, and centrifugation-induced flocculation allows the determination of two critical concentrations of sol flocculation. The titrations of calcium phytate colloid at different concentrations provide information on the colloidal formation conditions. Moreover, a study on flocculation kinetics was made by turbidity measurements. (author)
Stegemann, J.
Oxygen uptake kinetics, following defined variations of work load changes allow to estimate the contribution of aerob and anaerob energy supply which is the base for determining work capacity. Under the aspect of long duration missions with application of adequate dosed countermeasures, a reliable estimate of the astronaut's work capacity is important to adjust the necessary inflight training. Since the kinetics of oxygen uptake originate in the working muscle group itself, while measurements are performed at the mouth, various influences within the oxygen transport system might disturb the determinations. There are not only detraining effects but also well-known other influences, such as blood- and fluid shifts induced by weightlessness. They might have an impact on the circulatory system. Some of these factors have been simulated by immersion, blood donation, and changing of the body position.
Reconsidering relations between nuclear energy and security concepts
International Nuclear Information System (INIS)
Irie, Kazutomo
2004-01-01
Relations between nuclear energy and security concepts can be clarified through investigation into the multivocal nature of security concepts. While military uses of nuclear energy significantly influence national security, peaceful uses of nuclear energy contribute energy security, which is an expanded concept of national security. Military and peaceful uses of nuclear energy have reciprocal actions, thus influencing national security and energy security, respectively. Nuclear security, which means security of nuclear systems themselves, recently attracts the attention of the international society. Nuclear security directly influences national security issues. On the other hand, along with nuclear safety, nuclear security becomes a prerequisite for energy security through peaceful uses of nuclear energy. In investigating into relations between nuclear energy and security concepts, the difficulty of translating the English word of 'nuclear security' into Japanese as well as other languages is found. (author)
Lee, Tae Geol; Park, Seung C.; Kim, Myung Soo
1996-03-01
Mass-analyzed ion kinetic energy (MIKE) spectrum of CHO+ generated in the unimolecular dissociation of CH2OH+ was measured. Kinetic energy release distribution (KERD) was evaluated by analyzing the spectrum according to the algorithm developed previously. The average kinetic energy release evaluated from the distribution was extraordinarily large, 1.63 eV, corresponding to 75% of the reverse barrier of the reaction. A global analytical potential energy surface was constructed such that the experimental energetics was represented and that various features in the ab initio potential energy surface were closely reproduced. Classical trajectory calculation was carried out with the global analytical potential energy surface to investigate the causes for the extraordinarily large kinetic energy release. Based on the detailed dynamical calculations, it was found that the strained bending forces at the transition state and strengthening of the CO bond from double to triple bond character were mainly responsible for such a significant kinetic energy release. In addition, the dissociation products H2 and CHO+ ion were found to be rotationally excited in the trajectory calculations. This was attributed to the asymmetry of the transition state and the release of asymmetric bending forces. Also, the bending vibrational modes of CHO+ and the H2 stretching mode, which are coupled with the bending coordinates, were found to be moderately excited.
Kinetic energy and angular momentum of free particles in the gyratonic pp-waves space-times
Maluf, J. W.; da Rocha-Neto, J. F.; Ulhoa, S. C.; Carneiro, F. L.
2018-06-01
Gyratonic pp-waves are exact solutions of Einstein’s equations that represent non-linear gravitational waves endowed with angular momentum. We consider gyratonic pp-waves that travel in the z direction and whose time dependence on the variable is given by Gaussians, so that the waves represent short bursts of gravitational radiation propagating in the z direction. We evaluate numerically the geodesics and velocities of free particles in the space-time of these waves, and find that after the passage of the waves both the kinetic energy and the angular momentum per unit mass of the particles are changed. Therefore there is a transfer of energy and angular momentum between the gravitational field and the free particles, so that the final values of the energy and angular momentum of the free particles may be smaller or larger in magnitude than the initial values.
Souza, S. R.; Donangelo, R.; Lynch, W. G.; Tsang, M. B.
2018-03-01
The properties of the kinetic energy spectra of light isotopes produced in the breakup of a nuclear source and during the de-excitation of its products are examined. The initial stage, at which the hot fragments are created, is modeled by the statistical multifragmentation model, whereas the Weisskopf-Ewing evaporation treatment is adopted to describe the subsequent fragment de-excitation, as they follow their classical trajectories dictated by the Coulomb repulsion among them. The energy spectra obtained are compared to available experimental data. The influence of the fusion cross section entering into the evaporation treatment is investigated and its influence on the qualitative aspects of the energy spectra turns out to be small. Although these aspects can be fairly well described by the model, the underlying physics associated with the quantitative discrepancies remains to be understood.
Dispersion relation and Landau damping of waves in high-energy density plasmas
International Nuclear Information System (INIS)
Zhu Jun; Ji Peiyong
2012-01-01
We present a theoretical investigation on the propagation of electromagnetic waves and electron plasma waves in high energy density plasmas using the covariant Wigner function approach. Based on the covariant Wigner function and Dirac equation, a relativistic quantum kinetic model is established to describe the physical processes in high-energy density plasmas. With the zero-temperature Fermi–Dirac distribution, the dispersion relation and Landau damping of waves containing the relativistic quantum corrected terms are derived. The relativistic quantum corrections to the dispersion relation and Landau damping are analyzed by comparing our results with those obtained in classical and non-relativistic quantum plasmas. We provide a detailed discussion on the Landau damping obtained in classical plasmas, non-relativistic Fermi plasmas and relativistic Fermi plasmas. The contributions of the Bohm potential, the Fermi statistics pressure and relativistic effects to the dispersion relation and Landau damping of waves are quantitatively calculated with real plasma parameters. (paper)
Directory of Open Access Journals (Sweden)
Karlsson J
2015-07-01
Full Text Available Johan Karlsson, Saba Atefyekta, Martin Andersson Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden Abstract: The osseointegration capacity of bone-anchoring implants can be improved by the use of drugs that are administrated by an inbuilt drug delivery system. However, to attain superior control of drug delivery and to have the ability to administer drugs of varying size, including proteins, further material development of drug carriers is needed. Mesoporous materials have shown great potential in drug delivery applications to provide and maintain a drug concentration within the therapeutic window for the desired period of time. Moreover, drug delivery from coatings consisting of mesoporous titania has shown to be promising to improve healing of bone-anchoring implants. Here we report on how the delivery of an osteoporosis drug, alendronate, can be controlled by altering pore size and surface energy of mesoporous titania thin films. The pore size was varied from 3.4 nm to 7.2 nm by the use of different structure-directing templates and addition of a swelling agent. The surface energy was also altered by grafting dimethylsilane to the pore walls. The drug uptake and release profiles were monitored in situ using quartz crystal microbalance with dissipation (QCM-D and it was shown that both pore size and surface energy had a profound effect on both the adsorption and release kinetics of alendronate. The QCM-D data provided evidence that the drug delivery from mesoporous titania films is controlled by a binding–diffusion mechanism. The yielded knowledge of release kinetics is crucial in order to improve the in vivo tissue response associated to therapeutic treatments. Keywords: mesoporous titania, controlled drug delivery, release kinetics, alendronate, QCM-D
Energy related applications of elementary particle physics
International Nuclear Information System (INIS)
Rafelski, J.
1989-01-01
Study of muon catalysis of nuclear fusion and phenomena commonly referred to as cold fusion has been central to our effort. Muon catalyzed fusion research concentrated primarily on the identification of energy efficient production of muons, and the understanding and control of the density dependence of auto-poisoning (sticking) of the catalyst. We have also developed the in-flight fusion description of the tμ-d reaction, and work in progress shows promise in explaining the fusion cycle anomalies and smallness of sticking as a consequence of the dominant role of such reactions. Our cold fusion work involved the exploration of numerous environments for cold fusion reactions in materials used in the heavy water electrolysis, with emphasis on reactions consistent with the conventional knowledge of nuclear physics reactions. We then considered the possibility that a previously unobserved ultra-heavy particle X - is a catalyst of dd fusion, explaining the low intensity neutrons observed by Jones et. al. 29 refs
Energy Relations between the European Union and North Africa
Directory of Open Access Journals (Sweden)
Sarah Kilpeläinen
2013-06-01
Full Text Available This article discusses European Union (EU-North Africa energy relations with a special focus on renewables in North Africa, arguing that the research so far has not taken due account of North African perceptions of EU external energy policy. It is argued that current research on EU-North African relations has not taken sufficient note of the multidimensionality of energy or addressed the inconsistent nature of EU policy making. However, addressing these issues is vital in approaching EU-North Africa energy relations and EU policy towards North Africa in general. The study of perceptions is introduced as one way to develop research further, to give further impetus on understanding how EU-North African energy relations develop and to understand energy relations in their complexity.
Cabrera-Trujillo, R.; Cruz, S. A.; Soullard, J.
The energy deposited by swift atomic-ion projectiles when colliding with a given target material has been a topic of special scientific interest for the last century due to the variety of applications of ion beams in modern materials technology as well as in medical physics. In this work, we summarize our contributions in this field as a consequence of fruitful discussions and enlightening ideas put forward by one of the main protagonists in stopping power theory during the last three decades: Jens Oddershede. Our review, mainly motivated by Jens' work, evolves from the extension of the orbital implementation of the kinetic theory of stopping through the orbital local plasma approximation, its use in studies of orbital and total mean excitation energies for the study of atomic and molecular stopping until the advances on generalized oscillator strength and sum rules in the study of stopping cross sections. Finally, as a tribute to Jens' work on the orbital implementation of the kinetic theory of stopping, in this work we present new results on the use of the Thomas-Fermi-Dirac-Weizsäcker density functional for the calculation of orbital and total atomic mean excitation energies. The results are applied to free-atoms and and extension is done to confined atoms - taking Si as an example - whereby target pressure effects on stopping are derived. Hence, evidence of the far-yield of Jens' ideas is given.
Hybrid Fluid/Kinetic Modeling Of Magnetized High Energy Density Plasmas
Hansen, David; Held, Eric; King, Jacob; Stoltz, Peter; Masti, Robert; Srinivasan, Bhuvana
2017-10-01
MHD modeling with an equation of state (EOS) of the Rayleigh-Taylor (RT) instabily in Z indicates that it is seeded by the electro-thermal instability. Large thermodynamic drives associated with gradients at the interface between the liner and the coronal regions distort distribution functions and likely lead to non-local transport effects in a plasma which varies from weakly to strongly coupled. In this work, we discuss using effective potential theory along with a Chapman-Ensksog-like (CEL) formalism to develop hybrid fluid/kinetic modeling capabilities for these plasmas. Effective potential theory addresses the role of Coulomb collisions on transport across coupling regimes and the CEL approach bridges the gap between full-blow kinetic simulations and the EOS tables, which only depend locally on density and temperature. Quantitative results on the Spitzer problem across coupling coupling regimes will be presented as a first step. DOE Grant No. DE-SC0016525.
International Nuclear Information System (INIS)
Fontaine, G.H.; Hattendorf, B.; Oberli, F.; Bourdon, B.; Guenther, D.
2009-01-01
Full text: Systematic dependence of mass discrimination on ICP operating parameters was investigated for two MCICPMS instruments, a Nu Plasma HR and a Nu Plasma 1700, which differ both in acceleration voltage and spectrometer geometry. Gas temperature variations were determined by absolute pressure measurements at the vacuum interface. Their influence on ion kinetic energy as monitored by means of a retardation filter fitted in front of an ion counting detector will be discussed and compared to effects resulting from variations in acceleration voltage. (author)
DEFF Research Database (Denmark)
Knüppel, Thyge; Thuring, P.; Kumar, S
2011-01-01
is proposed that delivers a short-term power reserve from the kinetic energy in the wind turbine (WT) inertia, while considering the inherent characteristics of a wind power plant. The aim is to contribute with a fast power reserve to stabilize the frequency drop during large and sudden production deficits......With increased penetration of converter interfaced generation, synchronous generators may start to be displaced to keep the overall power balance. As a consequence the resulting inertia in the system may decrease and make the power system more exposed to frequency excursions. Here, a control...
Giardina, G.; Mandaglio, G.; Nasirov, A. K.; Anastasi, A.; Curciarello, F.; Fazio, G.
2018-05-01
The sensitivity of reaction mechanism in the formation of compound nucleus (CN) by the analysis of kinetic energy spectra of light particles and of reaction products are shown. The dependence of the P CN fusion probability of reactants and W sur survival probability of CN against fission at its deexcitation on the mass and charge symmetries in the entrance channel of heavy-ion collisions, as well as on the neutron numbers is discussed. The possibility of conducting a complex program of investigations of the complete fusion by reliable ways depends on the detailed and refined methods of experimental and theoretical analyses.
Energy Technology Data Exchange (ETDEWEB)
Harwood, John Harry [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM (Brazil)
1997-12-31
The work talks about the possibility of make use of kinetic energy of Amazonian rivers for power generation using an equipment similar to wind conversion systems. One of this equipment was constructed and tested in Solimoes river (Amazonas State, Brazil) and utilized for supply an isolated property. Besides the problems with waste in the river and problems to fix the equipment, the result was very interesting and the cost was competitive with others options. The work presents also a scheme of equipment 3 refs., 4 figs., 1 tab.
Proton-induced fission cross sections on "2"0"8Pb at high kinetic energies
International Nuclear Information System (INIS)
Rodriguez-Sanchez, J.L.; Benlliure, J.; Paradela, C.; Ayyad, Y.; Alvarez-Pol, H.; Cortina-Gil, D.; Pietras, B.; Ramos, D.; Vargas, J.; Taieb, J.; Chatillon, A.; Belier, G.; Boutoux, G.; Gorbinet, T.; Laurent, B.; Martin, J.F.; Pellereau, E.; Casarejos, E.; Rodriguez-Tajes, C.
2014-01-01
Total fission cross sections of "2"0"8Pb induced by protons have been determined at 370 A, 500 A, and 650 A MeV. The experiment was performed at GSI Darmstadt where the combined use of the inverse kinematics technique with an efficient detection setup allowed us to determine these cross sections with an uncertainty below 6%. This result was achieved by an accurate beam selection and registration of both fission fragments in coincidence which were also clearly distinguished from other reaction channels. These data solve existing discrepancies between previous measurements, providing new values for the Prokofiev systematics. The data also allow us to investigate the fission process at high excitation energies and small deformations. In particular, some fundamental questions about fission dynamics have been addressed, which are related to dissipative and transient time effects. (authors)
Evaluation of Nitrate and Nitrite Reduction Kinetics Related to Liquid-Air-Interface Corrosion
International Nuclear Information System (INIS)
Li, Xiaoji; Gui, F.; Cong, Hongbo; Brossia, C.S.; Frankel, G.S.
2014-01-01
Liquid-air interface (LAI) corrosion has been a concern for causing leaks in the carbon steel tanks used for holding high-level radioactive liquid waste. To assist in understanding the mechanism of LAI corrosion, the kinetics of nitrate and nitrite reduction reactions were investigated electrochemically. Cyclic voltammetry and cathodic polarization measurements indicated that the nitrite reduction reaction exhibited faster kinetics than the nitrate reduction reaction at higher cathodic overpotential. However, the primary reduction reaction at the open circuit potential under aerated conditions was the oxygen reduction reaction. The reduction of residual oxygen was also the dominant cathodic reaction at open circuit potential in deaerated conditions. Moreover, the kinetics of oxygen reduction on steel electrodes were significantly influenced by the sample immersion conditions (partial vs. full) for aerated liquid nuclear waste simulants, but not for deaerated conditions. Lastly, the gaseous products formed during LAI corrosion were analyzed using the gas detector tube method and gas chromatography-mass spectrometry and found to contain NH 3 , NO 2 and NO. However, the results suggested that these products were caused by the local acidification generated by the hydrolysis of cations after LAI corrosion underwent extensive propagation, instead of being directly reduced in alkaline conditions. Thus, the results in this work showed that the kinetics of nitrate and nitrite reduction could not generate a salt concentration cell in the meniscus region to cause LAI corrosion
International Nuclear Information System (INIS)
Keisler, Ryan; Schmidt, Fabian
2013-01-01
We consider the prospects for measuring the pairwise kinetic Sunyaev-Zel'dovich (kSZ) signal from galaxy clusters discovered in large photometric surveys such as the Dark Energy Survey (DES). We project that the DES cluster sample will, in conjunction with existing mm-wave data from the South Pole Telescope (SPT), yield a detection of the pairwise kSZ signal at the 8σ-13σ level, with sensitivity peaking for clusters separated by ∼100 Mpc distances. A next-generation version of SPT would allow for a 18σ-30σ detection and would be limited by variance from the kSZ signal itself and the residual thermal Sunyaev-Zel'dovich (tSZ) signal. Throughout our analysis, we assume photometric redshift errors that wash out the signal for clusters separated by ∼<50 Mpc; a spectroscopic survey of the DES sample would recover this signal and allow for a 26σ-43σ detection, and would again be limited by kSZ/tSZ variance. Assuming a standard model of structure formation, these high-precision measurements of the pairwise kSZ signal will yield detailed information on the gas content of the galaxy clusters. Alternatively, if the gas can be sufficiently characterized by other means (e.g., using tSZ, X-ray, or weak lensing), then the relative velocities of the galaxy clusters can be isolated, thereby providing a precision measurement of gravity on 100 Mpc scales. We briefly consider the utility of these measurements for constraining theories of modified gravity.
78 FR 26394 - Renewable Energy and Related Services: Recent Developments
2013-05-06
... INTERNATIONAL TRADE COMMISSION [Investigation No. 332-534] Renewable Energy and Related Services: Recent Developments AGENCY: United States International Trade Commission. ACTION: Extension of date for... USTR in investigation No. 332-534, Renewable Energy and Related Services: Recent Developments. DATES...
Assistance to States on Policies Related to Wind Energy Issues
Energy Technology Data Exchange (ETDEWEB)
Brown, Matthew, H; Decesaro, Jennifer; DOE Project Officer - Keith Bennett
2005-07-15
This final report summarizes work carried out under agreement with the US Department of Energy, related to wind energy policy issues. This project has involved a combination of outreach and publications on wind energy, with a specific focus on educating state-level policymakers. Education of state policymakers is vitally important because state policy (in the form of incentives or regulation) is a crucial part of the success of wind energy. State policymakers wield a significant influence over all of these policies. They are also in need of high quality, non-biased educational resources which this project provided. This project provided outreach to legislatures, in the form of meetings designed specifically for state legislators and legislative staff, responses to information requests on wind energy, and publications. The publications addressed: renewable energy portfolio standards, wind energy transmission, wind energy siting, case studies of wind energy policy, avian issues, economic development, and other related issues. These publications were distributed to legislative energy committee members, and chairs, legislative staff, legislative libraries, and other related state officials. The effect of this effort has been to provide an extensive resource of information about wind information for state policymakers in a form that is useful to them. This non-partisan information has been used as state policymakers attempt to develop their own policy proposals related to wind energy in the states.
Dwarkanath, Pratibha; Hsu, Jean W; Tang, Grace J; Anand, Pauline; Thomas, Tinku; Thomas, Annamma; Sheela, C N; Kurpad, Anura V; Jahoor, Farook
2016-02-01
In India, the prevalence of low birth weight is high in women with a low body mass index (BMI), suggesting that underweight women are not capable of providing adequate energy and protein for fetal growth. Furthermore, as pregnancy progresses, there is increased need to provide methyl groups for methylation reactions associated with the synthesis of new proteins and, unlike normal-BMI American women, low-BMI Indian women are unable to increase methionine transmethylation and remethylation rates as pregnancy progresses from trimester 1 to 3. This also negatively influences birth weight. The aim was to determine the effect of dietary supplementation with energy and protein from 12 ± 1 wk of gestation to time of delivery compared with no supplement on pregnancy outcomes, protein kinetics, and the fluxes of the methyl group donors serine and glycine. Protein kinetics and serine and glycine fluxes were measured by using standard stable isotope tracer methods in the fasting and postprandial states in 24 pregnant women aged 22.9 ± 0.7 y with low BMIs [BMI (in kg/m(2)) ≤18.5] at 12 ± 1 wk (trimester 1) and 30 ± 1 wk (trimester 3) of gestation. After the first measurement, subjects were randomly assigned to either receive the supplement (300 kcal/d, 15 g protein/d) or no supplement. Supplementation had no significant effect on any variable of pregnancy outcome, and except for fasting state decreases in leucine flux (125 ± 7.14 compared with 113 ± 5.06 μmol ⋅ kg(-1) ⋅ h(-1); P = 0.04) and nonoxidative disposal (110 ± 6.97 compared with 101 ± 3.69 μmol ⋅ kg(-1) ⋅ h(-1); P = 0.02) from trimesters 1 to 3, it had no effect on any other leucine kinetic variable or urea, glycine, and serine fluxes. We conclude that in Indian women with a low BMI, supplementation with energy and protein from week 12 of pregnancy to time of delivery does not improve pregnancy outcome, whole-body protein kinetics, or serine and glycine fluxes. © 2016 American Society for Nutrition.
Asymmetric interdependence in the Czech–Russian energy relations
International Nuclear Information System (INIS)
Binhack, Petr; Tichý, Lukáš
2012-01-01
This paper addresses the issue of asymmetric energy relations between the Czech Republic and the Russian Federation. The theory of interdependence is a widely used concept in political and economic studies of international relations. As can be seen from the analysis of Czech–Russian energy relations and its costs and benefits, the interdependence cannot be limited to a situation of equal interdependence. Energy sensitivity and vulnerability of the Czech Republic towards Russia is considered as a key source of power for the energy policy of Russia vis-à-vis the Czech Republic. The evidence for this claim can be found in the procedures and expressions of Russia’s energy policy. On the other hand, the energy policy of the Czech Republic is influenced by the European Union and its focus on the liberalization of the energy market, diversification of the currently existing transportation routes and legislative proposals aimed at strengthening the EU’s own energy security. The European Union significantly contributes to an increase of the energy security of the Czech Republic. The European Union and regional cooperation (such as the V4 group) could balance out the asymmetry of interdependence, thus lowering the sensitivity and vulnerability of the Czech Republic towards Russia. - Highlights: ► We examine energy relations between the Czech Republic and the Russian Federation. ► We use the concept of asymmetric interdependence in energy relations. ► Energy sensitivity and vulnerability of the Czech Republic are key variables. ► The asymmetric interdependence is a source of power for Russian energy policy. ► The EU and V4 cooperation contribute to an energy security of the Czech Republic.
Directory of Open Access Journals (Sweden)
Q Joyce Han
Full Text Available Right ventricular (RV function has increasingly being recognized as an important predictor for morbidity and mortality in patients with pulmonary arterial hypertension (PAH. The increased RV after-load increase RV work in PAH. We used time-resolved 3D phase contrast MRI (4D flow MRI to derive RV kinetic energy (KE work density and energy loss in the pulmonary artery (PA to better characterize RV work in PAH patients.4D flow and standard cardiac cine images were obtained in ten functional class I/II patients with PAH and nine healthy subjects. For each individual, we calculated the RV KE work density and the amount of viscous dissipation in the PA.PAH patients had alterations in flow patterns in both the RV and the PA compared to healthy subjects. PAH subjects had significantly higher RV KE work density than healthy subjects (94.7±33.7 mJ/mL vs. 61.7±14.8 mJ/mL, p = 0.007 as well as a much greater percent PA energy loss (21.1±6.4% vs. 2.2±1.3%, p = 0.0001 throughout the cardiac cycle. RV KE work density and percent PA energy loss had mild and moderate correlations with RV ejection fraction.This study has quantified two kinetic energy metrics to assess RV function using 4D flow. RV KE work density and PA viscous energy loss not only distinguished healthy subjects from patients, but also provided distinction amongst PAH patients. These metrics hold promise as imaging markers for RV function.
Han, Q Joyce; Witschey, Walter R T; Fang-Yen, Christopher M; Arkles, Jeffrey S; Barker, Alex J; Forfia, Paul R; Han, Yuchi
2015-01-01
Right ventricular (RV) function has increasingly being recognized as an important predictor for morbidity and mortality in patients with pulmonary arterial hypertension (PAH). The increased RV after-load increase RV work in PAH. We used time-resolved 3D phase contrast MRI (4D flow MRI) to derive RV kinetic energy (KE) work density and energy loss in the pulmonary artery (PA) to better characterize RV work in PAH patients. 4D flow and standard cardiac cine images were obtained in ten functional class I/II patients with PAH and nine healthy subjects. For each individual, we calculated the RV KE work density and the amount of viscous dissipation in the PA. PAH patients had alterations in flow patterns in both the RV and the PA compared to healthy subjects. PAH subjects had significantly higher RV KE work density than healthy subjects (94.7±33.7 mJ/mL vs. 61.7±14.8 mJ/mL, p = 0.007) as well as a much greater percent PA energy loss (21.1±6.4% vs. 2.2±1.3%, p = 0.0001) throughout the cardiac cycle. RV KE work density and percent PA energy loss had mild and moderate correlations with RV ejection fraction. This study has quantified two kinetic energy metrics to assess RV function using 4D flow. RV KE work density and PA viscous energy loss not only distinguished healthy subjects from patients, but also provided distinction amongst PAH patients. These metrics hold promise as imaging markers for RV function.
The relative importance of fluid and kinetic frequency shifts of an electron plasma wave
International Nuclear Information System (INIS)
Winjum, B. J.; Fahlen, J.; Mori, W. B.
2007-01-01
The total nonlinear frequency shift of a plasma wave including both fluid and kinetic effects is estimated when the phase velocity of the wave is much less than the speed of light. Using a waterbag or fluid model, the nonlinear frequency shift due to harmonic generation is calculated for an arbitrary shift in the wavenumber. In the limit where the wavenumber does not shift, the result is in agreement with previously published work [R. L. Dewar and J. Lindl, Phys. Fluids 15, 820 (1972); T. P. Coffey, ibid. 14, 1402 (1971)]. This shift is compared to the kinetic shift of Morales and O'Neil [G. J. Morales and T. M. O'Neil, Phys. Rev. Lett. 28, 417 (1972)] for wave amplitudes and values of kλ D of interest to Raman backscatter of a laser driver in inertial confinement fusion
The relative importance of fluid and kinetic frequency shifts of an electron plasma wave
Winjum, B. J.; Fahlen, J.; Mori, W. B.
2007-10-01
The total nonlinear frequency shift of a plasma wave including both fluid and kinetic effects is estimated when the phase velocity of the wave is much less than the speed of light. Using a waterbag or fluid model, the nonlinear frequency shift due to harmonic generation is calculated for an arbitrary shift in the wavenumber. In the limit where the wavenumber does not shift, the result is in agreement with previously published work [R. L. Dewar and J. Lindl, Phys. Fluids 15, 820 (1972); T. P. Coffey, Phys. Fluids 14, 1402 (1971)]. This shift is compared to the kinetic shift of Morales and O'Neil [G. J. Morales and T. M. O'Neil, Phys. Rev. Lett. 28, 417 (1972)] for wave amplitudes and values of kλD of interest to Raman backscatter of a laser driver in inertial confinement fusion.
Rompas, P. T. D.; Taunaumang, H.; Sangari, F. J.
2018-02-01
The paper presents validation of the numerical program that computes the distribution of marine current velocities in the Bangka strait and the kinetic energy potential in the form the distributions of available power per area in the Bangka strait. The numerical program used the RANS model where the pressure distribution in the vertical assumed to be hydrostatic. The 2D and 3D numerical program results compared with the measurement results that are observation results to the moment conditions of low and high tide currents. It found no different significant between the numerical results and the measurement results. There are 0.97-2.2 kW/m2 the kinetic energy potential in the form the distributions of available power per area in the Bangka strait when low tide currents, whereas when high tide currents of 1.02-2.1 kW/m2. The results show that to be enabling the installation of marine current turbines for construction of power plant in the Bangka strait, North Sulawesi, Indonesia.
Directory of Open Access Journals (Sweden)
M. Wacławczyk
2017-11-01
Full Text Available In this paper we propose two approaches to estimating the turbulent kinetic energy (TKE dissipation rate, based on the zero-crossing method by Sreenivasan et al. (1983. The original formulation requires a fine resolution of the measured signal, down to the smallest dissipative scales. However, due to finite sampling frequency, as well as measurement errors, velocity time series obtained from airborne experiments are characterized by the presence of effective spectral cutoffs. In contrast to the original formulation the new approaches are suitable for use with signals originating from airborne experiments. The suitability of the new approaches is tested using measurement data obtained during the Physics of Stratocumulus Top (POST airborne research campaign as well as synthetic turbulence data. They appear useful and complementary to existing methods. We show the number-of-crossings-based approaches respond differently to errors due to finite sampling and finite averaging than the classical power spectral method. Hence, their application for the case of short signals and small sampling frequencies is particularly interesting, as it can increase the robustness of turbulent kinetic energy dissipation rate retrieval.
International Nuclear Information System (INIS)
Kusuoka, Hideo; Tsuneoka, Yutaka; Inoue, Michitoshi; Abe, Hiroshi; Watari, Hiroshi.
1982-01-01
Effect of artificial blood, FC 43 (Perfluorochemicals) on the kinetics of high-energy phosphate in the myocardium was evaluated by 31 P-NMR which permits a continuous and non-invasive assessment of in vivo phosphorus compounds. Cardiac perfusion was carried out on a excised rat heart with a Krebs-Henseleit modified solution and FC 43 alternately. Under the normal condition, ischemic condition, and at second perfusion amounts of intramyocardial creatine phosphoric acid, ATP, and inorganic phosphorus were determined by 31 P-NMR. Coronary flow was simultaneously estimated. The ischemic state due to interruption of perfusion resulted in a decrease in creatine phosphoric acid, which was associated with an increase in inorganic phosphorus and intracellular acidosis. No change of ATP amount was observed under ischemic state. With resumption of perfusion, the levels of creatine phosphoric acid and inorganic phosphorus rapidly returned to the normal. In the group of FC 43, coronary flow was 2.68 ml/min/g of the heart weight, about 1/2 of that of the Krebs-Henseleit group (5.68 ml/min/g of the heart weight). In controls, there was no difference between the two groups concerning creatine phosphoric acid level and recovery of creatine phospohric acid level after ischemia. These results showed that FC 43 supplies sufficient oxygen, and has no effect on the kinetics of energy in the myocardium. (Ueda, J.)
Coupling the photon kinetics of soft photons with high energy photons
Silva, L. O.; Bingham, R.
2017-10-01
The description of electromagnetic fields based on the generalized photon kinetic theory, which takes advantage of the Wigner-Moyal description for the corresponding classical field theory, is capable of capturing collective plasma dynamics in the relativistic regime driven by broadband incoherent or partially coherent sources. We explore the possibility to extend this description to include the dynamics of hard photons in the plasma, whose interaction is dominated by single scattering processes. Examples of the modification of classical plasma instabilities due to the presence of hard photons is discussed. Work supported by the European Research Council (ERC-AdG-2015 InPairs Grant No. 695088).
Kinetics and thermodynamic properties related to the drying of 'Cabacinha' pepper fruits
Hellismar W. da Silva; Renato S. Rodovalho; Marya F. Velasco; Camila F. Silva; Luís S. R. Vale
2016-01-01
ABSTRACT The objective of this study was to determine and model the drying kinetics of 'Cabacinha' pepper fruits at different temperatures of the drying air, as well as obtain the thermodynamic properties involved in the drying process of the product. Drying was carried out under controlled conductions of temperature (60, 70, 80, 90 and 100 °C) using three samples of 130 g of fruit, which were weighed periodically until constant mass. The experimental data were adjusted to different mathemati...
Energy Technology Data Exchange (ETDEWEB)
Castin, N. [Structural Materials Group, Nuclear Materials Science Institute, Studiecentrum voor Kerneenergie Centre d' etude de l' energie nucleaire (SCK CEN), Boeretang 200, B-2400 Mol (Belgium); Universite Libre de Bruxelles (ULB), Physique des Solides Irradies et Nanostructures (PSIN), CP234 Boulevard du triomphe, Brussels (Belgium); Malerba, L. [Structural Materials Group, Nuclear Materials Science Institute, Studiecentrum voor Kerneenergie Centre d' etude de l' energie nucleaire (SCK CEN), Boeretang 200, B-2400 Mol (Belgium)], E-mail: lmalerba@sckcen.be
2009-09-15
We significantly improved a previously proposed method to take into account chemical and also relaxation effects on point-defect migration energy barriers, as predicted by an interatomic potential, in a rigid lattice atomistic kinetic Monte Carlo simulation. Examples of energy barriers are rigorously calculated, including chemical and relaxation effects, as functions of the local atomic configuration, using a nudged elastic bands technique. These examples are then used to train an artificial neural network that provides the barriers on-demand during the simulation for each configuration encountered by the migrating defect. Thanks to a newly developed training method, the configuration can include a large number of neighbour shells, thereby properly including also strain effects. Satisfactory results have been obtained when the configuration includes different chemical species only. The problems encountered in the extension of the method to configurations including any number of point-defects are stated and solutions to tackle them are sketched.
The Opacity of Russian-Ukrainian Energy Relations
International Nuclear Information System (INIS)
Dubien, A.
2007-01-01
Energy issues lie at the heart of Ukraine's economic, political and strategic challenges. A year after the 'orange revolution', the 'gas war' served to highlight the country's vulnerable position, being 80% dependent on imports of gas and having the world's most energy hungry economy. The 2005 crisis also highlighted the extreme opacity of the country's bilateral relations with Russia, which are governed as much by the interests surrounding Gazprom's relations as by those of the state. Yanukovich's return to power in the summer of 2006 coincided with a relative appeasement of relations with Moscow and a new division of spheres of influence in the Ukrainian energy sector. (author)
PFI-ZEKE (Pulsed Field Ionization-Zero Electron Kinetic Energy) para el estudio de iones
Castaño, F.; Fernández, J. A.; Basterretxea, A. Longarte. F.; Sánchez Rayo, M. N.; Martínez, R.
Entre las áreas hacia donde ha evolucionado la Química en los últimos años están los estudios de sistemas con especies reactivas de alta energía y los dominados por fuerzas intermoleculares débiles, con energías de unas pocas kcal/mol. En efecto, el estudio de las propiedades de los iones, comenzando por su relación con la molécula neutra de la que procede, la energía de ionización, los estados vibracionales y rotacionales, energías de enlace de Van der Waals entre el ión y una amplia variedad de otras moléculas, sus confórmeros o isómeros y sus reacciones o semi-reacciones químicas están en la raíz de la necesidad de la espectroscopía conocida como PFI-ZEKE, Pulsed Field Ionization-Zero Electron Kinetic Energy. Entre las aplicaciones que requieren estos conocimientos se encuentran la generación de plasmas para la fabricación de semiconductores, memorias magnéticas, etc, así como los sistemas astrofísicos, la ionosfera terrestre, etc. La espectroscopía ZEKE es una evolución de las de fluorescencia inducida por láser, LIF, ionización multifotónica acrecentada por resonancia, REMPI, con uno y dos colores y acoplada a un sistema de tiempo de vuelo, REMPI-TOF-MS, y las espectroscopías de doble resonancia IR-UV y UV-UV. Sus espectros y la ayuda de cálculos ab inicio permite determinar las energías de enlace de complejos de van der Waals en estados fundamental y excitados, identificar confórmeros e isómeros, obtener energías de ionización experimentales aproximadas (100 cm-1) y otras variables de interés. Al igual que con LIF, REMPI y dobles resonancias, es posible utilizar muestras gaseosas, pero los espectros están muy saturados de bandas y su interpretación es difícil o imposible. Se evitan estas dificultades estudiando las moléculas o complejos en expansiones supersónicas, donde la T de los grados de libertad solo alcanzan unos pocos K. Para realizar experimentos de ZEKE hay que utilizar una propiedad recientemente
Cross-beam energy transfer: On the accuracy of linear stationary models in the linear kinetic regime
Debayle, A.; Masson-Laborde, P.-E.; Ruyer, C.; Casanova, M.; Loiseau, P.
2018-05-01
We present an extensive numerical study by means of particle-in-cell simulations of the energy transfer that occurs during the crossing of two laser beams. In the linear regime, when ions are not trapped in the potential well induced by the laser interference pattern, a very good agreement is obtained with a simple linear stationary model, provided the laser intensity is sufficiently smooth. These comparisons include different plasma compositions to cover the strong and weak Landau damping regimes as well as the multispecies case. The correct evaluation of the linear Landau damping at the phase velocity imposed by the laser interference pattern is essential to estimate the energy transfer rate between the laser beams, once the stationary regime is reached. The transient evolution obtained in kinetic simulations is also analysed by means of a full analytical formula that includes 3D beam energy exchange coupled with the ion acoustic wave response. Specific attention is paid to the energy transfer when the laser presents small-scale inhomogeneities. In particular, the energy transfer is reduced when the laser inhomogeneities are comparable with the Landau damping characteristic length of the ion acoustic wave.
Some problems of solar-terrestrial energy relations
International Nuclear Information System (INIS)
Kovalevskij, I.V.
1982-01-01
Energy aspects of relations of phenomena occurring on the Sun, in the interplanetary space, magnetosphere, ionosphere and on the Earth's surface are discussed. Particular attention is given to the energy radiated by the Sun (flares, coronal holes). The problems are considered of the energy transfer and transformation in high-velocity and flare flows of solar wind. Estimates are performed: of densities of various types of energy of the interplanetary space at the Earth's orbit level; energy fluxes incident on the magnetosphere; energy accumulated inside the magnetosphere; a series of energy parameters of magnetic storms. It is pointed out that nowadays one of the main problems of the magnetosphere physics is studying ways of the interplanatary space energy transfer into the magnetosphere. In this connection some problems are investigated: plasma penetration through the dayside magnetopause, solar wind plasma entry into the magnetotail, the electric field effect on transition region plasma penetration into the distant magnetotail
McCrudden, Michael C; Keir, Daniel A; Belfry, Glen R
2017-06-01
We examined the effects of inserting 3-s recovery periods during high-intensity cycling exercise at 25-s and 10-s intervals on pulmonary oxygen uptake (V̇o 2p ), muscle deoxygenation [deoxyhemoglobin (HHb)], their associated kinetics (τ), and energy system contributions. Eleven men (24 ± 3 yr) completed two trials of three cycling protocols: an 8-min continuous protocol (CONT) and two 8-min intermittent exercise protocols with work-to-rest periods of 25 s to 3 s (25INT) and 10 s to 3 s (10INT). Each protocol began with a step-transition from a 20-W baseline to a power output (PO) of 60% between lactate threshold and maximal V̇o 2p (Δ60). This PO was maintained for 8 min in CONT, whereas 3-s periods of 20-W cycling were inserted every 10 s and 25 s after the transition to Δ60 in 10INT and 25INT, respectively. Breath-by-breath gas exchange measured by mass spectrometry and turbine and vastus lateralis [HHb] measured by near-infrared spectroscopy were recorded throughout. Arterialized-capillary lactate concentration ([Lac - ]) was obtained before and 2 min postexercise. The τV̇o 2p was lowest ( P 0.05) between conditions. Postexercise [Lac - ] was lowest ( P exercise speeded V̇o 2p kinetics and reduced overall V̇o 2p , suggesting an increased reliance on PCr-derived phosphorylation during the work period of INT compared with an identical PO performed continuously. NEW & NOTEWORTHY We report novel observations on the effects of differing heavy-intensity work durations between 3-s recovery periods on pulmonary oxygen uptake (V̇o 2p ) kinetics, muscle deoxygenation, and energy system contributions. Relative to continuous exercise, V̇o 2p kinetics are faster in intermittent exercise, and increased frequency of 3-s recovery periods improves microvascular O 2 delivery and reduces V̇o 2p and arterialized-capillary lactate concentration. The metabolic burden of identical intensity work is altered when performed intermittently vs. continuously. Copyright
Kinetic energy spectrum and polarization of neutrons from the reaction 12C(p,n)X at 590 MeV
International Nuclear Information System (INIS)
Arnold, J.
1998-01-01
The kinetic energy spectrum and the polarization of the PSI neutron beam produced in the reaction 12 C(p,n)X at 0 with 590 MeV polarized protons were investigated. A strong energy dependence of the neutron beam polarization is observed which was not expected at the time the neutron beam was built. (orig.)
Food and agriculture in relation to energy, environment and resources
Energy Technology Data Exchange (ETDEWEB)
Winteringham, F P.W. [International Atomic Energy Agency, Vienna (Austria). Joint FAO/IAEA Div. of Atomic Energy in Food and Agriculture
1980-03-01
Current trends in cultivated land, world population, agricultural practices food and energy are briefly reviewed. The rise in energy input/food energy output ratios with modernization is indicated. Nutritional needs, and trends in food and energy demand per capita are also indicated. Some emerging constraints in relation to soil fertility and agrochemical usage are identified. A growing pressure on land for ''energy and chemical farming'' is foreseen. Losses of native and added soil nitrogen, comparable with total industrial fertilizer nitrogen fixation, seem unavoidable for two decades at least. This consideration of trends and their interactions suggests the need for more effective interdisciplinary study, longer-term planning and international cooperation.
Food and agriculture in relation to energy, environment and resources
International Nuclear Information System (INIS)
Winteringham, F.P.W.
1980-01-01
Current trends in cultivated land, world population, agricultural practices food and energy are briefly reviewed. The rise in energy input/food energy output ratios with modernization is indicated. Nutritional needs, and trends in food and energy demand per capita are also indicated. Some emerging constraints in relation to soil fertility and agrochemical usage are identified. A growing pressure on land for ''energy and chemical farming'' is foreseen. Losses of native and added soil nitrogen, comparable with total industrial fertilizer nitrogen fixation, seem unavoidable for two decades at least. This consideration of trends and their interactions suggests the need for more effective interdisciplinary study, longer-term planning and international cooperation. (author)
An analysis of buildings-related energy use in manufacturing
Energy Technology Data Exchange (ETDEWEB)
Niefer, M.J.; Ashton, W.B.
1997-04-01
This report presents research by the Pacific Northwest National Laboratory (PNNL) to develop improved estimates of buildings-related energy use in US manufacturing facilities. The research was supported by the Office of Building Technology, State and Community Programs (BTS), Office of Energy Efficiency and Renewable Energy (EERE), US Department of Energy (DOE). The research scope includes only space conditioning and lighting end uses. In addition, this study also estimates the energy savings potential for application of selected commercial buildings technologies being developed by the BTS office to manufacturing and other industrial process facilities. 17 refs., 2 figs., 19 tabs.
Energy Technology Data Exchange (ETDEWEB)
Roldan Soriano, M.
2009-07-01
The erosive capacity of raindrops is function of mass (size) and terminal velocity. Drop mass and velocity govern the inherent erosivity of rainfall through kinetic energy. Kinetic energy is a very important property of the rainfall because it is one of the sources of energy in the process of water erosion. Vegetative canopy intercepts the raindrops and causes a variation on this rainfall kinetic energy due to modification of diameters and velocities distributions. If the height of canopy is enough, the bigger intercepted drops could achieve high velocities and their kinetic energies can increases. In this paper a quantitative evaluation of the increase of kinetic energy of intercepted drops is obtained and it is showed that this kinetic energy increases exponentially with vegetation height. (Author) 9 refs.
Directory of Open Access Journals (Sweden)
Mojtaba Ahmadi
2016-11-01
Full Text Available The aqueous degradation of Reactive Yellow 84 (RY84 by potassium peroxydisulfate (K2S2O8 has been studied in laboratory scale experiments. The effect of the initial concentrations of potassium peroxydisulfate and RY84, pH and temperature on RY84 degradation were also examined. Experimental data were analyzed using first and second-order kinetics. The degradation kinetics of RY84 of the potassium peroxydisulfate process followed the second-order reaction kinetics. These rate constants have an extreme values similar to of 9.493 mM−1min−1 at a peroxydisulfate dose of 4 mmol/L. Thermodynamic parameters such as activation (Ea and Gibbs free energy (ΔG° were also evaluated. The negative value of ΔGo and Ea shows the spontaneous reaction natural conditions and exothermic nature.
The Eastern Partnership and the EU-Turkey Energy Relations
Directory of Open Access Journals (Sweden)
Demiryol Tolga
2014-10-01
Full Text Available This article discusses the prospects and challenges of energy cooperation between the European Union (EU and Turkey within the context of the Eastern Partnership (EaP. Part of the EaP agenda is to advance energy cooperation between the EU and the partner states, particularly regarding the diversification of import routes. As an energy corridor between the EU and the hydrocarbon-rich Caspian states, Turkey is a strategic asset for European energy security. Turkey also has economic ties and political capital in the Caspian region that can help the EU reach out to its eastern partners. Despite robust incentives for cooperation, however, the EU-Turkey energy partnership has so far failed to meet mutual expectations. This article argues that this is primarily due to the inability of the two actors to credibly commit to regional energy cooperation. Commitment problem stems from two factors. First, the predominance of national energy interests over communal ones undermines credible commitment. The variation in energy needs of Member States prevents the EU from acting in unison in external energy policy. Similarly, Turkey also prioritizes its own energy security, particularly in its relations with suppliers, which undermines cooperation with the EU. Second, the EU and Turkey hold divergent perspectives on the potential political payoffs of energy cooperation. Turkish decision makers are convinced that energy cooperation warrants palpable progress in Turkey’s accession while most EU actors appear hesitant to establish a direct connection between energy and accession.
Track etch parameters and annealing kinetics assessment of protons of low energy in CR-39 detector
International Nuclear Information System (INIS)
Jain, R.K.; Kumar, Ashok; Singh, B.K.
2012-01-01
Highlights: ► We calibrate CR-39 detector with very low energy protons. ► We establish linear relationship between track diameter and time/energy up to 200 keV. ► We determine activation energy of annealing using different models. ► We justify concept of single annealing activation energy in CR-39. - Abstract: In this paper threshold of the registration sensitivity of very low energy proton in CR-39 is investigated. Irradiation of CR-39 (poly-allyl-diglycol carbonate) was carried out with very low energy mono energetic protons of 20–60 keV from a mini proton accelerator. Nearly 10 4 /cm 2 fluence of protons was used. The variation of track diameter with etching time as well as proton energy response curve was carefully calibrated. The bulk and track etch rates were measured by using proton track diameters. Bulk etch rate was also measured by the thickness of removed surface layer. The thermal annealing of proton track at temperatures ranging from 100 to 200 °C in CR-39 was studied by several models. Activation energy of annealed CR-39 detectors was calculated by slope of track etch rate and temperature plot. The data of proton tracks of 200, 250 and 300 keV from 400 kV Van-de-Graaff accelerator was also used and compared with the track diameters of different energies of proton.
International Nuclear Information System (INIS)
Hadj-Bachir, Mokrane
2012-06-01
Whereas existing codes (PIC, hybrid or kinetic) used to model electron transport by describing experimentally observed physical phenomena at different time scales and space scales are notably time and memory consuming (from several hours to several days of computing time), this academic work aimed at developing, from an existing code, a simple and quasi analytical model of transport of fast electron in intense current. This model allows the calculation of energy losses of beam electrons, as well as the heating a materials crossed within a relatively short time (about a minute), with ranges of about 100 microns and a resolution of about 1 micron. After a recall on the theory of fast electron transport, the author presents the structure of the code as it existed before this improvement work, and then the introduced modifications which addressed electronic conductivity, the collisional stopping power, and the distribution function. Obtained results are finally discussed
Another two dark energy models motivated from Karolyhazy uncertainty relation
Energy Technology Data Exchange (ETDEWEB)
Sun, Cheng-Yi; Yang, Wen-Li; Song, Yu. [Northwest University, Institute of Modern Physics, Xian (China); Yue, Rui-Hong [Ningbo University, Faculty of Science, Ningbo (China)
2012-03-15
The Karolyhazy uncertainty relation indicates that there exists a minimal detectable cell {delta}t{sup 3} over the region t{sup 3} in Minkowski space-time. Due to the energy-time uncertainty relation, the energy of the cell {delta}t {sup 3} cannot be less {delta}t{sup -1}. Then we get a new energy density of metric fluctuations of Minkowski spacetime as {delta}t{sup -4}. Motivated by the energy density, we propose two new dark-energy models. One model is characterized by the age of the universe and the other is characterized by the conformal age of the universe. We find that in the two models, the dark energy mimics a cosmological constant in the late time. (orig.)
The interdependence of European–Russian energy relations
International Nuclear Information System (INIS)
Harsem, Øistein; Harald Claes, Dag
2013-01-01
The aim of this article is to explore this dynamic interdependent relationship between Russia and Europe in the field of energy. Based on the concept of interdependence and perspectives on the political aspects of trade relations we discuss how Russia can exercise power based on its energy resources and how the EU can compensate for its lack of power in the energy game with other trade related capabilities. In particular we explore the implications of the lack of a full-fledged EU foreign energy policy towards Russia, with the somewhat counter-intuitive conclusion that the EU countries, on average, not necessarily are better off with a common foreign energy policy. - Highlights: • We examine Russian–European gas (inter)dependence. • East-European countries are most dependent on Russian gas in Europe. • EU countries, on average, are not better off with a common foreign energy policy
Structural and kinetic mapping of side-chain exposure onto the protein energy landscape.
Bernstein, Rachel; Schmidt, Kierstin L; Harbury, Pehr B; Marqusee, Susan
2011-06-28
Identification and characterization of structural fluctuations that occur under native conditions is crucial for understanding protein folding and function, but such fluctuations are often rare and transient, making them difficult to study. Native-state hydrogen exchange (NSHX) has been a powerful tool for identifying such rarely populated conformations, but it generally reveals no information about the placement of these species along the folding reaction coordinate or the barriers separating them from the folded state and provides little insight into side-chain packing. To complement such studies, we have performed native-state alkyl-proton exchange, a method analogous to NSHX that monitors cysteine modification rather than backbone amide exchange, to examine the folding landscape of Escherichia coli ribonuclease H, a protein well characterized by hydrogen exchange. We have chosen experimental conditions such that the rate-limiting barrier acts as a kinetic partition: residues that become exposed only upon crossing the unfolding barrier are modified in the EX1 regime (alkylation rates report on the rate of unfolding), while those exposed on the native side of the barrier are modified predominantly in the EX2 regime (alkylation rates report on equilibrium populations). This kinetic partitioning allows for identification and placement of partially unfolded forms along the reaction coordinate. Using this approach we detect previously unidentified, rarely populated conformations residing on the native side of the barrier and identify side chains that are modified only upon crossing the unfolding barrier. Thus, in a single experiment under native conditions, both sides of the rate-limiting barrier are investigated.
Relativistic energy-dispersion relations of 2D rectangular lattices
Ata, Engin; Demirhan, Doğan; Büyükkılıç, Fevzi
2017-04-01
An exactly solvable relativistic approach based on inseparable periodic well potentials is developed to obtain energy-dispersion relations of spin states of a single-electron in two-dimensional (2D) rectangular lattices. Commutation of axes transfer matrices is exploited to find energy dependencies of the wave vector components. From the trace of the lattice transfer matrix, energy-dispersion relations of conductance and valence states are obtained in transcendental form. Graphical solutions of relativistic and nonrelativistic transcendental energy-dispersion relations are plotted to compare how lattice parameters V0, core and interstitial size of the rectangular lattice affects to the energy-band structures in a situation core and interstitial diagonals are of equal slope.
Energy drinks and alcohol-related risk among young adults.
Caviness, Celeste M; Anderson, Bradley J; Stein, Michael D
2017-01-01
Energy drink consumption, with or without concurrent alcohol use, is common among young adults. This study sought to clarify risk for negative alcohol outcomes related to the timing of energy drink use. The authors interviewed a community sample of 481 young adults, aged 18-25, who drank alcohol in the last month. Past-30-day energy drink use was operationalized as no-use, use without concurrent alcohol, and concurrent use of energy drinks with alcohol ("within a couple of hours"). Negative alcohol outcomes included past-30-day binge drinking, past-30-day alcohol use disorder, and drinking-related consequences. Just over half (50.5%) reported no use of energy drinks,18.3% reported using energy drinks without concurrent alcohol use, and 31.2% reported concurrent use of energy drinks and alcohol. Relative to those who reported concurrent use of energy drinks with alcohol, and controlling for background characteristics and frequency of alcohol consumption, those who didn't use energy drinks and those who used without concurrent alcohol use had significantly lower binge drinking, negative consequences, and rates of alcohol use disorder (P energy drink without concurrent alcohol groups on any alcohol-related measure (P > .10 for all outcomes). Concurrent energy drink and alcohol use is associated with increased risk for negative alcohol consequences in young adults. Clinicians providing care to young adults could consider asking patients about concurrent energy drink and alcohol use as a way to begin a conversation about risky alcohol consumption while addressing 2 substances commonly used by this population.
Foland, Andrew Dean
2007-01-01
Energy is the central concept of physics. Unable to be created or destroyed but transformable from one form to another, energy ultimately determines what is and isn''t possible in our universe. This book gives readers an appreciation for the limits of energy and the quantities of energy in the world around them. This fascinating book explores the major forms of energy: kinetic, potential, electrical, chemical, thermal, and nuclear.
International Nuclear Information System (INIS)
Levin, J.C.; Biedermann, C.; Cederquist, H.; Liljeby, L.; Short, R.T.; Sellin, I.A.
1989-01-01
This paper contrasts two methods of production of multiply charged ions which may have application in future hot-atom chemistry experiments. Interest in extending the study of ion-atom collisions from MeV to keV to eV energies has grown rapidly in the last decade as previously inaccessible astrophysical, fusion, and spectroscopic problems have been addressed. One of these methods involves highly charged secondary beams formed from ions created in dilute gas samples irradiated by fast (MeV), high-charge-state, heavy ions. The measurements show, however, that such ions often have mean recoil energies two orders of magnitude higher than kinetic energies of ions in similar charge states resulting from vacancy cascades of atomic inner shells photoionized by synchrotron x rays. These results may be applicable to development of a cold source of highly charged ions featuring low energy spread and good angular definition. Results from other laboratories (Grandin et al at Ganil, Ullrich et al in Frankfurt, and Watson et al at Texas A ampersand M) will also be discussed
Energy Technology Data Exchange (ETDEWEB)
Tatry, B
1976-02-01
The feasibility of using solar energy to feed an autonomous station providing electric current continuously was studied. As an energy storage device a 'superflywheel' (rotor with composite fibers - magnetic bearings) would be used. Results show that such an experiment can be reasonably envisaged only in highly sunny countries and that it becomes non profitable at our latitudes, despite the very good performance of the flywheel storage device.
Sinclair, Jonathan; Taylor, Paul J
2014-10-01
Musculoskeletal injuries in the lower extremities are common in military recruits. Army boots have frequently been cited as a potential mechanism behind these high injury rates. In response to this, the British Army introduced new footwear models, the PT-03 (cross-trainer) and PT1000 (running shoes), which are issued to each new recruit in an attempt to reduce the incidence of these injuries. The aim of the current investigation was to examine the kinetics and kinematic of the PT-03 and PT1000 footwear in relation to conventional army boots. Thirteen participants ran at 4.0 m·s in each footwear condition. Three-dimensional kinematics from the hip, knee, and ankle were measured using an 8-camera motion analysis system. In addition, simultaneous ground reaction forces were obtained. Kinetic parameters were obtained alongside joint kinematics and compared using repeated-measures analyses of variance. The kinetic analysis revealed that impact parameters were significantly greater when running in the army boot compared with the PT-03 and PT1000. The kinematic analysis indicated that, in comparison with the PT-03 and PT1000, running in army boots was associated with significantly greater eversion and tibial internal rotation. It was also found that when running in the PT-03 footwear, participants exhibited significantly greater hip adduction and knee abduction compared with the army boots and PT1000. The results of this study suggest that the army boots and PT-03 footwear are associated with kinetic and kinematic parameters that have been linked to the etiology of injury; thus, it is recommended that the PT1000 footwear be adopted for running exercises.
Cognitive determinants of energy balance-related behaviours : measurement issues
Kremers, Stef P J; Visscher, Tommy L S; Seidell, Jacob C; van Mechelen, Willem; Brug, Johannes
2005-01-01
The burden of disease as a result of overweight and obesity calls for in-depth examination of the main causes of behavioural actions responsible for weight gain. Since weight gain is the result of a positive energy balance, these behavioural actions are referred to as 'energy balance-related
Extrapolations of nuclear binding energies from new linear mass relations
DEFF Research Database (Denmark)
Hove, D.; Jensen, A. S.; Riisager, K.
2013-01-01
We present a method to extrapolate nuclear binding energies from known values for neighboring nuclei. We select four specific mass relations constructed to eliminate smooth variation of the binding energy as function nucleon numbers. The fast odd-even variations are avoided by comparing nuclei...
Lipsky, Leah M
2009-11-01
The inverse relation between energy density (kcal/g) and energy cost (price/kcal) has been interpreted to suggest that produce (fruit, vegetables) is more expensive than snacks (cookies, chips). The objective of this study was to show the methodologic weakness of comparing energy density with energy cost. The relation between energy density and energy cost was replicated in a random-number data set. Additionally, observational data were collected for produce and snacks from an online supermarket. Variables included total energy (kcal), total weight (g), total number of servings, serving size (g/serving), and energy density (kcal/g). Price measures included energy cost ($/kcal), total price ($), unit price ($/g), and serving price ($/serving). Two-tailed t tests were used to compare price measures by food category. Relations between energy density and price measures within food categories were examined with the use of Spearman rank correlation analysis. The relation between energy density and energy cost was shown to be driven by the algebraic properties of these variables. Food category was strongly correlated with both energy density and food price measures. Energy cost was higher for produce than for snacks. However, total price and unit price were lower for produce. Serving price and serving size were greater for produce than for snacks. Within food categories, energy density was uncorrelated with most measures of food price, except for a weak positive correlation with serving price within the produce category. The findings suggest the relation between energy density and food price is confounded by food category and depends on which measure of price is used.
A kinetic theory of diffusion in general relativity with cosmological scalar field
International Nuclear Information System (INIS)
Calogero, Simone
2011-01-01
A new model to describe the dynamics of particles undergoing diffusion in general relativity is proposed. The evolution of the particle system is described by a Fokker-Planck equation without friction on the tangent bundle of spacetime. It is shown that the energy-momentum tensor for this matter model is not divergence-free, which makes it inconsistent to couple the Fokker-Planck equation to the Einstein equations. This problem can be solved by postulating the existence of additional matter fields in spacetime or by modifying the Einstein equations. The case of a cosmological scalar field term added to the left hand side of the Einstein equations is studied in some details. For the simplest cosmological model, namely the flat Robertson-Walker spacetime, it is shown that, depending on the initial value of the cosmological scalar field, which can be identified with the present observed value of the cosmological constant, either unlimited expansion or the formation of a singularity in finite time will occur in the future. Future collapse into a singularity also takes place for a suitable small but positive present value of the cosmological constant, in contrast to the standard diffusion-free scenario
Energy Technology Data Exchange (ETDEWEB)
Duke, Dana Lynn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-11-12
This Ph.D. dissertation describes a measurement of the change in mass distributions and average total kinetic energy (TKE) release with increasing incident neutron energy for fission of ^{235}U and ^{238}U. Although fission was discovered over seventy-five years ago, open questions remain about the physics of the fission process. The energy of the incident neutron, En, changes the division of energy release in the resulting fission fragments, however, the details of energy partitioning remain ambiguous because the nucleus is a many-body quantum system. Creating a full theoretical model is difficult and experimental data to validate existing models are lacking. Additional fission measurements will lead to higher-quality models of the fission process, therefore improving applications such as the development of next-generation nuclear reactors and defense. This work also paves the way for precision experiments such as the Time Projection Chamber (TPC) for fission cross section measurements and the Spectrometer for Ion Determination in Fission (SPIDER) for precision mass yields.
Reaction of hydrogen with Ag(111): binding states, minimum energy paths, and kinetics.
Montoya, Alejandro; Schlunke, Anna; Haynes, Brian S
2006-08-31
The interaction of atomic and molecular hydrogen with the Ag(111) surface is studied using periodic density functional total-energy calculations. This paper focuses on the site preference for adsorption, ordered structures, and energy barriers for H diffusion and H recombination. Chemisorbed H atoms are unstable with respect to the H(2) molecule in all adsorption sites below monolayer coverage. The three-hollow sites are energetically the most favorable for H chemisorption. The binding energy of H to the surface decreases slightly up to one monolayer, suggesting a small repulsive H-H interaction on nonadjacent sites. Subsurface and vacancy sites are energetically less favorable for H adsorption than on-top sites. Recombination of chemisorbed H atoms leads to the formation of gas-phase H(2) with no molecular chemisorbed state. Recombination is an exothermic process and occurs on the bridge site with a pronounced energy barrier. This energy barrier is significantly higher than that inferred from experimental temperature-programmed desorption (TPD) studies. However, there is significant permeability of H atoms through the recombination energy barrier at low temperatures, thus increasing the rate constant for H(2) desorption due to quantum tunneling effects, and improving the agreement between experiment and theory.
Press problem related to nuclear energy news reporting
International Nuclear Information System (INIS)
Arai, Mitsuo
2008-01-01
Since the event of Niigataken Chuetsu-oki Earthquake in 2007 and the subsequent press reports on damage of nuclear power station after it, a stance of media is being questioned. In order to clear this problem, basic organizational structure of the press related to nuclear energy news was analyzed. Local news department, social news department, science news department and economical news department involve in nuclear energy news the accordance with their own situations and concerns. This structure makes problem of nuclear energy news reporting complicated. Changing this system is required but very difficult. It is concluded that the press problem around nuclear energy news is strange. (author)
INVESTIGATION OF THE KINETICS OF DRYING SEEDS THISTLE IN VORTEX CHAMBER WITH MICROWAVE ENERGY SUPPLY
Directory of Open Access Journals (Sweden)
D. A. Kazartsev
2015-01-01
Full Text Available In the study of the current state of the theory, techniques and technologies for processing of milk thistle showed up a number of problems. One of those moments - the need to promptly provide quality and efficient process for drying seeds, but Russia has not produced special equipment for postharvest processing of seeds of milk thistle, and used for drying grain domestic appliances, represented mainly by mining and drum dryers, it is not suitable for thistle. This is due to the fact that, firstly, in the dewatering process is necessary to provide a relatively low final moisture drying product (5-6 %, and, secondly, to keep their beneficial substance in full, which imposes additional restrictions on the conditions of drying. One way of creating a new drying technology development and implementation in the industry of high-intensive devices with active hydrodynamic regimes with microwave energy supply, providing in many cases, higher technical and economic indicators. Therefore, the use of devices with swirling flow of heat-carrier for the intensification of the process of drying of dispersed materials is both theoretical interest and practical value. Microwave drying is based on the fact that the dielectric properties of water and dry food substances are different: the wet material is heated much faster than dry. During the microwave drying temperature wetter internal layers higher than the exterior more dehydrated (which creates a "right" - from the inner to the outer layers of the product - the gradient of moisture mass transfer is not realizable in any of the other known methods of drying. Milk thistle seeds have a unique composition: 25-32 % fatty oil, 15-17 % protein, 26 % fat, in the-soluble (B group and fat-soluble (A, D, E, K, F vitamins, mono- and disaccharides, macro- and trace elements (copper, zinc, selenium, dietary fiber and enzymes, mucus, up to 5 % (glucose, etc., phenolic compounds including flaviolignans 2-3% (silibinin
Kinetics and energy efficiency for the degradation of 1,4-dioxane by electro-peroxone process
Energy Technology Data Exchange (ETDEWEB)
Wang, Huijiao; Bakheet, Belal; Yuan, Shi; Li, Xiang; Yu, Gang [School of Environment, Tsinghua University, Beijing 100084 (China); Murayama, Seiichi [Power and Industrial Systems R& D Center, Toshiba Corporation, Fuchu-shi, Tokyo (Japan); Wang, Yujue, E-mail: wangyujue@tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China)
2015-08-30
Highlights: • E-peroxone couples electrolysis with ozonation to driven peroxone reaction for pollutant degradation. • Significant amounts of ·OH can be efficiently produced in the E-peroxone process. • E-peroxone greatly enhances 1,4-dioxane degradation kinetics compared with ozonation and electrolysis. • E-peroxone consumes less energy for 1,4-dioxane mineralization than ozonation and electrolysis. • E-peroxone offers a cost-effective and energy-efficient alternative to degrade 1,4-dioxane. - Abstract: Degradation of 1,4-dioxane by ozonation, electrolysis, and their combined electro-peroxone (E-peroxone) process was investigated. The E-peroxone process used a carbon-polytetrafluorethylene cathode to electrocatalytically convert O{sub 2} in the sparged ozone generator effluent (O{sub 2} and O{sub 3} gas mixture) to H{sub 2}O{sub 2}. The electro-generated H{sub 2}O{sub 2} then react with sparged O{sub 3} to yield aqueous ·OH, which can in turn oxidize pollutants rapidly in the bulk solution. Using p-chlorobenzoic acid as ·OH probe, the pseudo-steady concentration of ·OH was determined to be ∼0.744 × 10{sup −9} mM in the E-peroxone process, which is approximately 10 and 186 times of that in ozonation and electrolysis using a Pt anode. Thanks to its higher ·OH concentration, the E-peroxone process eliminated 96.6% total organic carbon (TOC) from a 1,4-dioxane solution after 2 h treatment with a specific energy consumption (SEC) of 0.376 kWh g{sup −1} TOC{sub removed}. In comparison, ozonation and electrolysis using a boron-doped diamond anode removed only ∼6.1% and 26.9% TOC with SEC of 2.43 and 0.558 kWh g{sup −1} TOC{sub removed}, respectively. The results indicate that the E-peroxone process can significantly improve the kinetics and energy efficiency for 1,4-dioxane mineralization as compared to the two individual processes. The E-peroxone process may thus offer a highly effective and energy-efficient alternative to treat 1,4-dioxane
Affective Influences on Energy-Related Decisions and Behaviors
Energy Technology Data Exchange (ETDEWEB)
Brosch, Tobias, E-mail: tobias.brosch@unige.ch [Department of Psychology, University of Geneva, Geneva (Switzerland); Swiss Center of Affective Sciences, University of Geneva, Geneva (Switzerland); Patel, Martin K. [Energy Group, Institute for Environmental Sciences, University of Geneva, Geneva (Switzerland); Energy Group, Forel Institute, University of Geneva, Geneva (Switzerland); Sander, David [Department of Psychology, University of Geneva, Geneva (Switzerland); Swiss Center of Affective Sciences, University of Geneva, Geneva (Switzerland)
2014-03-17
A successful energy transition will depend not only on the development of new energy technologies, but also on changes in the patterns of individual energy-related decisions and behaviors resulting in substantial reductions in energy demand. Across scientific disciplines, most theoretical approaches that try to understand energy-related decisions and behaviors focus mainly on cognitive processes, such as computations of utility (typically economic), the impact of cognitive heuristics, or the role of individual beliefs. While these models already explain important aspects of human decisions and behavior in the energy domain, we argue that an additional consideration of the contributions of emotional processes may be very fruitful for a deeper understanding of the issue. In this contribution, we outline a theoretical perspective on energy-related decisions and behaviors that integrates emotions, elicited by a cognitive-affective appraisal of the relevance of a situation, into a response system driving adaptive decisions and behaviors. We empirically investigate the explanatory power of the model variables to predict intentions to reduce energy use demonstrating that the appraisal–emotion variables are able to account for additional variance that is not explained by two established models focused on cognitive processes (theory of planned behavior and value-belief-norm theory). Finally, we discuss how the appraisal–emotion approach may be fruitfully integrated with other existing approaches and outline some questions for future research.
Affective Influences on Energy-Related Decisions and Behaviors
International Nuclear Information System (INIS)
Brosch, Tobias; Patel, Martin K.; Sander, David
2014-01-01
A successful energy transition will depend not only on the development of new energy technologies, but also on changes in the patterns of individual energy-related decisions and behaviors resulting in substantial reductions in energy demand. Across scientific disciplines, most theoretical approaches that try to understand energy-related decisions and behaviors focus mainly on cognitive processes, such as computations of utility (typically economic), the impact of cognitive heuristics, or the role of individual beliefs. While these models already explain important aspects of human decisions and behavior in the energy domain, we argue that an additional consideration of the contributions of emotional processes may be very fruitful for a deeper understanding of the issue. In this contribution, we outline a theoretical perspective on energy-related decisions and behaviors that integrates emotions, elicited by a cognitive-affective appraisal of the relevance of a situation, into a response system driving adaptive decisions and behaviors. We empirically investigate the explanatory power of the model variables to predict intentions to reduce energy use demonstrating that the appraisal–emotion variables are able to account for additional variance that is not explained by two established models focused on cognitive processes (theory of planned behavior and value-belief-norm theory). Finally, we discuss how the appraisal–emotion approach may be fruitfully integrated with other existing approaches and outline some questions for future research.
Affective influences on energy-related decisions and behaviors
Directory of Open Access Journals (Sweden)
Tobias eBrosch
2014-03-01
Full Text Available A successful energy transition will depend not only on the development of new energy technologies, but also on changes in the patterns of individual energy-related decisions and behaviors resulting in substantial reductions in energy demand. Across scientific disciplines, most theoretical approaches that try to understand energy-related decisions and behaviors focus mainly on cognitive processes, such as computations of utility (typically economic, the impact of cognitive heuristics, or the role of individual beliefs. While these models already explain important aspects of human decisions and behavior in the energy domain, we argue that an additional consideration of the contributions of emotional processes may be very fruitful for a deeper understanding of the issue. In this contribution, we outline a theoretical perspective on energy-related decisions and behaviors that integrates emotions, elicited by a cognitive-affective appraisal of the relevance of a situation, into a response system driving adaptive decisions and behaviors. We empirically investigate the explanatory power of the model variables to predict intentions to reduce energy use, demonstrating that the appraisal-emotion variables are able to account for additional variance that is not explained by two established models focused on cognitive processes (Theory of Planned Behavior and Value-Belief-Norm Theory. Finally, we discuss how the appraisal-emotion approach may be fruitfully integrated with other existing approaches and outline some questions for future research.
Lee, Ying Ping; Fujii, Manabu; Kikuchi, Tetsuro; Terao, Koumei; Yoshimura, Chihiro
2017-01-01
Oxidation and reduction kinetics of iron (Fe) and proportion of steady-state Fe(II) concentration relative to total dissolved Fe (steady-state Fe(II) fraction) were investigated in the presence of various types of standard humic substances (HS) with particular emphasis on the photochemical and thermal reduction of Fe(III) and oxidation of Fe(II) by dissolved oxygen (O2) and hydrogen peroxide (H2O2) at circumneutral pH (pH 7-8). Rates of Fe(III) reduction were spectrophotometrically determined...
Malaysian public perception towards nuclear power energy-related issues
Misnon, Fauzan Amin; Hu, Yeoh Siong; Rahman, Irman Abd.; Yasir, Muhamad Samudi
2017-01-01
Malaysia had considered nuclear energy as an option for future electricity generation during the 9th Malaysia Development Plan. Since 2009, Malaysia had implemented a number of important preparatory steps towards this goal, including the establishment of Nuclear Power Corporation of Malaysia (MNPC) as first Nuclear Energy Programme Implementing Organization (NEPIO) in Malaysia. In light of the establishment of MNPC, the National Nuclear Policy was formulated in 2010 and a new comprehensive nuclear law to replace the existing Atomic Energy Licensing Act (Act 304) is currently in the pipeline. Internationally, public acceptance is generally used to gauge the acceptance of nuclear energy by the public whenever a government decides to engage in nuclear energy. A public survey was conducted in between 14 March 2016 to 10 May 2016 focusing on the Malaysian public acceptance and perception towards the implementation of nuclear energy in Malaysia. The methodology of this research was aim on finding an overview of the general knowledge, public-relation recommendation, perception and acceptance of Malaysian towards the nuclear power development program. The combination of information gathered from this study can be interpreted as an indication of the complexity surrounding the development of nuclear energy and its relationship with the unique background of Malaysian demography. This paper will focus mainly on energy-related section in the survey in comparison with nuclear energy.
Krümpel, Johannes Hagen; Illi, Lukas; Lemmer, Andreas
2018-03-01
As a consequence of a growing share of solar and wind power, recent research on biogas production highlighted a need for demand-orientated, flexible gas production to provide grid services and enable a decentralized stabilization of the electricity infrastructure. Two-staged anaerobic digestion is particularly suitable for shifting the methane production into times of higher demand due to the spatio-temporal separation of hydrolysis and methanogenesis. To provide a basis for predicting gas production in an anaerobic filter, kinetic parameters of gas production have been determined experimentally in this study. A new methodology is used, enabling their determination during continuous operation. An order in methane production rate could be established by comparing the half lives of methane production. The order was beginning with the fastest: acetic acid>ethanol>butyric acid>iso-butyric acid>valeric acid>propionic acid>1,2propanediol>lactic acid. However, the mixture of a natural hydrolysate from the acidification tank appeared to produce methane faster than all single components tested.
International Nuclear Information System (INIS)
Howard, I A; March, N H
2010-01-01
The search for the single-particle kinetic energy functional T S [n] continues to be of major interest for density functional theory. Since it is expected to be generally applicable, exactly solvable models are of obvious interest. Here we focus on one, which is also of interest experimentally in magnetic trapping of ultracold fermion vapours. This is the model of independent harmonically trapped fermions in two dimensions. Here, the role of the von Weizsaecker inhomogeneity kinetic energy is a focal point, prompted also by the work of Delle Site (2005 J. Phys. A: Math. Gen. 38 7893).
International Nuclear Information System (INIS)
March, N.H.
2006-08-01
A differential equation for the Dirac density matrix γ(r, r'), given ground-state electron- and kinetic energy-densities, has been derived by March and Suhai for one- and two-level occupancy. For ten-electron spin-compensated spherical systems, it is shown here that γ ≡ γ[ρ, t g ] where ρ and t g are electron- and kinetic energy-densities. The philosophy of March and Suhai is confirmed beyond two-level filling. An important byproduct of the present approach is an explicit expression for the one-body potential of DFT in terms of the p-shell electron density. (author)
Kinetic study of dilute nitric acid treatment of corn stover at relatively high temperature
Energy Technology Data Exchange (ETDEWEB)
Zhang, R.; Lu, X.; Liu, Y.; Wang, X.; Zhang, S. [Tianjin University, School of Environmental Science and Technology, Tianjin (China)
2011-03-15
Corn stover was hydrolyzed using dilute nitric acid at 150 C. Several concentrations of HNO{sub 3} (0.2, 0.4 and 0.6 wt-%) and reaction times (0-60 min) were evaluated. The kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose, arabinose, acetic acid, and furfural in the hydrolysates were determined. The hydrolysates obtained from corn stover can be used to produce methane by an anaerobic fermentation process. Thus, the hydrolysis process of corn stover using dilute nitric acid can be conceived as the first stage of an integrated strategy for corn stover utilization. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Cell kinetic study on the relation between irradiation hypogeusia and taste buds in rats
Energy Technology Data Exchange (ETDEWEB)
Kubota, Hideharu; Furumoto, Keiichi [Nippon Dental Univ., Tokyo (Japan)
1998-12-01
The present study was designed to elucidate the mechanism of hypogeusia caused by irradiation. X-ray treatment at 10 Gy or 20 Gy was given to the maxillofacial region including the tongue in rats, and the involvement of taste bud for hypogeusia was investigated. In addition, cytological kinetics were immunohistologically studied using bromodeoxyuridine in the taste bud and in the lingual mucosal epithelium. The following results were obtained: In the 10 Gy group, the number of taste bud become less after the exposure, but no hypogeusia was observed during the experimental period. In the 20 Gy group, any labeled taste bud was not observed on the 7th day, and all taste buds disappeared by the 10th day. In the lingual mucosal epithelium, the number of basal cells decreased to the minimum, and the body weight and total water intake decreased coincidently in the 20 Gy group, which were few in the 10 Gy group. (author)
Cell kinetic study on the relation between irradiation hypogeusia and taste buds in rats
International Nuclear Information System (INIS)
Kubota, Hideharu; Furumoto, Keiichi
1998-01-01
The present study was designed to elucidate the mechanism of hypogeusia caused by irradiation. X-ray treatment at 10 Gy or 20 Gy was given to the maxillofacial region including the tongue in rats, and the involvement of taste bud for hypogeusia was investigated. In addition, cytological kinetics were immunohistologically studied using bromodeoxyuridine in the taste bud and in the lingual mucosal epithelium. The following results were obtained: In the 10 Gy group, the number of taste bud become less after the exposure, but no hypogeusia was observed during the experimental period. In the 20 Gy group, any labeled taste bud was not observed on the 7th day, and all taste buds disappeared by the 10th day. In the lingual mucosal epithelium, the number of basal cells decreased to the minimum, and the body weight and total water intake decreased coincidently in the 20 Gy group, which were few in the 10 Gy group. (author)
Energy storage cell impedance measuring apparatus, methods and related systems
Morrison, John L.; Morrison, William H.; Christophersen, Jon P.
2017-12-26
Energy storage cell impedance testing devices, circuits, and related methods are disclosed. An energy storage cell impedance measuring device includes a sum of sinusoids (SOS) current excitation circuit including differential current sources configured to isolate a ground terminal of the differential current sources from a positive terminal and a negative terminal of an energy storage cell. A method includes applying an SOS signal comprising a sum of sinusoidal current signals to the energy storage cell with the SOS current excitation circuit, each of the sinusoidal current signals oscillating at a different one of a plurality of different frequencies. The method also includes measuring an electrical signal at a positive terminal and a negative terminal of the energy storage cell, and computing an impedance of the energy storage cell at each of the plurality of different frequencies using the measured electrical signal.
Gamma-ray relative energy response of Ce: YAG crystal
International Nuclear Information System (INIS)
Zhang Jianhua; Zhang Chuanfei; Hu Mengchun; Peng Taiping; Wang Zhentong; Tang Dengpan; Zhao Guangjun
2010-01-01
Gamma-ray relative energy response of Ce: YAG crystal, which is important for pulsed γ-ray measurement, was studied in this work.The Ce: YAG crystal, which was developed at Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, was aligned point by point with γ-rays scattered from an industrial 60 Co line source. The γ-ray relative energy response was calculated using the mass attenuation coefficient. The results show that the numerical calculation method of γ-ray relative energy response is reliable, and the experimental method with multi-energy point γ-ray by Compton scattering is also feasible, that can be used for checking up correctness of the numerical calculation results. (authors)
Technology diffusion of energy-related products in residential markets
Energy Technology Data Exchange (ETDEWEB)
Davis, L.J.; Bruneau, C.L.
1987-05-01
Acceptance of energy-related technologies by end residential consumers, manufacturers of energy-related products, and other influential intermediate markets such as builders will influence the potential for market penetration of innovative energy-related technologies developed by the Department of Energy, Office of Building and Community Systems (OBCS). In this report, Pacific Northwest Laboratory reviewed the available information on technology adoption, diffusion, and decision-making processes to provide OBCS with a background and understanding of the type of research that has previously been conducted on this topic. Insight was gained as to the potential decision-making criteria and motivating factors that influence the decision-maker(s) selection of new technologies, and some of the barriers to technology adoption faced by potential markets for OBCS technologies.
Masti, Robert; Srinivasan, Bhuvana; King, Jacob; Stoltz, Peter; Hansen, David; Held, Eric
2017-10-01
Recent results from experiments and simulations of magnetically driven pulsed power liners have explored the role of early-time electrothermal instability in the evolution of the MRT (magneto-Rayleigh-Taylor) instability. Understanding the development of these instabilities can lead to potential stabilization mechanisms; thereby providing a significant role in the success of fusion concepts such as MagLIF (Magnetized Liner Inertial Fusion). For MagLIF the MRT instability is the most detrimental instability toward achieving fusion energy production. Experiments of high-energy density plasmas from wire-array implosions have shown the requirement for more advanced physics modeling than that of ideal magnetohydrodynamics. The overall focus of this project is on using a multi-fluid extended-MHD model with kinetic closures for thermal conductivity, resistivity, and viscosity. The extended-MHD model has been updated to include the SESAME equation-of-state tables and numerical benchmarks with this implementation will be presented. Simulations of MRT growth and evolution for MagLIF-relevant parameters will be presented using this extended-MHD model with the SESAME equation-of-state tables. This work is supported by the Department of Energy Office of Science under Grant Number DE-SC0016515.
Energy Technology Data Exchange (ETDEWEB)
Matteini, L.; Horbury, T. S.; Schwartz, S. J. [The Blackett Laboratory, Imperial College London, SW7 2AZ (United Kingdom); Pantellini, F. [LESIA, Observatoire de Paris, CNRS, UPMC, Universit Paris-Diderot, 5 Place Jules Janssen, F-92195 Meudon (France); Velli, M. [Department of Earth, Planetary, and Space Sciences, UCLA, California (United States)
2015-03-20
We investigate the properties of plasma fluid motion in the large-amplitude, low-frequency fluctuations of highly Alfvénic fast solar wind. We show that protons locally conserve total kinetic energy when observed from an effective frame of reference comoving with the fluctuations. For typical properties of the fast wind, this frame can be reasonably identified by alpha particles which, due to their drift with respect to protons at about the Alfvén speed along the magnetic field, do not partake in the fluid low-frequency fluctuations. Using their velocity to transform the proton velocity into the frame of Alfvénic turbulence, we demonstrate that the resulting plasma motion is characterized by a constant absolute value of the velocity, zero electric fields, and aligned velocity and magnetic field vectors as expected for unidirectional Alfvénic fluctuations in equilibrium. We propose that this constraint, via the correlation between velocity and magnetic field in Alfvénic turbulence, is the origin of the observed constancy of the magnetic field; while the constant velocity corresponding to constant energy can only be observed in the frame of the fluctuations, the corresponding constant total magnetic field, invariant for Galilean transformations, remains the observational signature in the spacecraft frame of the constant total energy in the Alfvén turbulence frame.
High energy density physics issues related to Future Circular Collider
Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Wollmann, D.; Piriz, A. R.
2017-07-01
A design study for a post-Large Hadron Collider accelerator named, Future Circular Collider (FCC), is being carried out by the International Scientific Community. A complete design report is expected to be ready by spring 2018. The FCC will accelerate two counter rotating beams of 50 TeV protons in a tunnel having a length (circumference) of 100 km. Each beam will be comprised of 10 600 proton bunches, with each bunch having an intensity of 1011 protons. The bunch length is of 0.5 ns, and two neighboring bunches are separated by 25 ns. Although there is an option for 5 ns bunch separation as well, in the present studies, we consider the former case only. The total energy stored in each FCC beam is about 8.5 GJ, which is equivalent to the kinetic energy of Airbus 380 (560 t) flying at a speed of 850 km/h. Machine protection is a very important issue while operating with such powerful beams. It is important to have an estimate of the damage caused to the equipment and accelerator components due to the accidental release of a partial or total beam at a given point. For this purpose, we carried out numerical simulations of full impact of one FCC beam on an extended solid copper target. These simulations have been done employing an energy deposition code, FLUKA, and a two-dimensional hydrodynamic code, BIG2, iteratively. This study shows that although the static range of a single FCC proton and its shower is about 1.5 m in solid copper, the entire beam will penetrate around 350 m into the target. This substantial increase in the range is due to the hydrodynamic tunneling of the beam. Our calculations also show that a large part of the target will be converted into high energy density matter including warm dense matter and strongly coupled plasmas.
Wang, Pei; He, Yi-Liang; Huang, Ching-Hua
2010-12-01
Fluoroquinolones (FQs) are a group of widely prescribed antibiotics and have been frequently detected in the aquatic environment. The reaction kinetics and transformation of seven FQs (ciprofloxacin (CIP), enrofloxacin (ENR), norfloxacin (NOR), ofloxacin (OFL), lomefloxacin (LOM), pipemidic acid (PIP) and flumequine (FLU)) and three structurally related amines (1-phenylpiperazine (PP), N-phenylmorpholine (PM) and 4-phenylpiperidine (PD)) toward chlorine dioxide (ClO(2)) were investigated to elucidate the behavior of FQs during ClO(2) disinfection processes. The reaction kinetics are highly pH-dependent, can be well described by a second-order kinetic model incorporating speciation of FQs, and follow the trend of OFL > ENR > CIP ∼ NOR ∼ LOM > > PIP in reactivity. Comparison among FQs and related amines and product characterization indicate that FQs' piperazine ring is the primary reactive center toward ClO(2). ClO(2) likely attacks FQ's piperazinyl N4 atom followed by concerted fragmentation involving piperazinyl N1 atom, leading to dealkylation, hydroxylation and intramolecular ring closure at the piperazine moiety. While FQs with tertiary N4 react faster with ClO(2) than FQs with secondary N4, the overall reactivity of the piperazine moiety also depends strongly on the quinolone ring through electronic effects. The reaction rate constants obtained in clean water matrix can be used to model the decay of CIP by ClO(2) in surface water samples, but overestimate the decay in wastewater samples. Overall, transformation of FQs, particularly for those with tertiary N4 amines, could be expected under typical ClO(2) disinfection conditions. However, the transformation may not eliminate antibacterial activity because of little destruction at the quinolone ring. Copyright © 2010 Elsevier Ltd. All rights reserved.
Fission-fragment angular distributions and total kinetic energies for 235U(n,f) from .18 to 8.83 MeV
International Nuclear Information System (INIS)
Meadows, J.W.; Budtz-Joergensen, C.
1982-01-01
A gridded ion chamber was used to measure the fission fragment angular distribution and total kinetic energy for the 235 U(n,f) reaction from 0.18 to 8.81 MeV neutron energy. The anisotropies are in generally good agreement with earlier measurements. The average total kinetic energy is approx. 0.2 MeV greater than the thermal value at neutron energies < 2 MeV and shows a sudden decrease of approx. 0.8 MeV between 4 and 5 MeV neutron energy, well below the (n, n'f) threshold. Possible causes of this decrease are a change in the mass distribution or decreased shell effects in the heavy fragment
Uncertainty relations, zero point energy and the linear canonical group
Sudarshan, E. C. G.
1993-01-01
The close relationship between the zero point energy, the uncertainty relations, coherent states, squeezed states, and correlated states for one mode is investigated. This group-theoretic perspective enables the parametrization and identification of their multimode generalization. In particular the generalized Schroedinger-Robertson uncertainty relations are analyzed. An elementary method of determining the canonical structure of the generalized correlated states is presented.
Energy-range relation and mean energy variation in therapeutic particle beams
International Nuclear Information System (INIS)
Kempe, Johanna; Brahme, Anders
2008-01-01
Analytical expressions for the mean energy and range of therapeutic light ion beams and low- and high-energy electrons have been derived, based on the energy dependence of their respective stopping powers. The new mean energy and range relations are power-law expressions relevant for light ion radiation therapy, and are based on measured practical ranges or known tabulated stopping powers and ranges for the relevant incident particle energies. A practical extrapolated range, R p , for light ions was defined, similar to that of electrons, which is very closely related to the extrapolated range of the primary ions. A universal energy-range relation for light ions and electrons that is valid for all material mixtures and compounds has been developed. The new relation can be expressed in terms of the range for protons and alpha particles, and is found to agree closely with experimental data in low atomic number media and when the difference in the mean ionization energy is low. The variation of the mean energy with depth and the new energy-range relation are useful for accurate stopping power and mass scattering power calculations, as well as for general particle transport and dosimetry applications
Energy Technology Data Exchange (ETDEWEB)
Nallathambi Gunaseelan, V. [Department of Zoology, PSG College of Arts and Science, Coimbatore 641 014 (India)
2009-04-15
In this study, we examined the production of Jatropha curcus plants on 1 ha of rain fed dry lands. All of the plant components that would result from plantation tending, fruit harvesting and processing were sampled for their yield and chemical composition, and then subjected to the biochemical methane potential (BMP) assay. The component parts exhibited significant variation in BMP which was reflected in their ultimate methane yield which ranged from 0.08 to 0.97 L g{sup -1} VS added, and their first order kinetics which ranged from 0.07 to 0.14 d{sup -1}. We examined two integrated utilization schemes: the first which converted plant prunings, fruit hulls and de-oiled seed cake to methane, and the oil to fatty acid methyl-ester (FAME); the second was to convert the seeds, plant prunings and fruit hulls entirely to methane. The basis for the plantation was, a density of 4444 plant ha{sup -1} (1.5 m x 1.5 m spacing), with a seed yield of 0.911 kg TS plant{sup -1} (1 kg total weight) with an oil content of 35% providing an annual oil yield of 1.42 t y{sup -1}. The corresponding yields of pruned leaves, fruit hulls and de-oiled cake are 0.97, 1.0, and 2.35 t VS ha y{sup -1}, respectively. An integrated scheme of producing biogas by means of anaerobic digestion of the latter components and oil for biodiesel would produce 90 GJ ha{sup -1} y{sup -1} in total with the oil being 54 GJ. The alternative biogas only option which would convert the seed oil into methane instead of biodiesel would produce 97 GJ ha{sup -1} y{sup -1}. (author)
Prediction of energy-related technology for next 30 years
Energy Technology Data Exchange (ETDEWEB)
Hashiguchi, Isao; Kondo, Satoru
1987-12-01
The report outlines major results of a survey concerning technologies expected to emerge during the next 30 years that was carried out by the Japan's Science and Technology Agency using the DELPHI method. The survey covered 51 technical issues in energy-related areas including fossil energy, nucler energy, natural energy, biomass and energy utilization techniques, and process-related areas including exploration, collection/extraction, transportation/storage, power generation, resources conversion and substitution. For each technical issue, investigation is made on its importance, time of realization, restrictions, procedure and responsible organization for promoting research and development, and government policy. Results show that the importance of nuclear energy will continue to increase and that diversification of energy sources, such as shift to coal, will also become more important. It is indicated that technological breakthroughs, such as the development of new superconducting materials, will accelerate the development of other techniques in related areas and simultaneously increase the importance of such techniques. The survey provides valuable basic data serving for predicting future social changes that may be caused by technical innovation or a shift in view on technology in the economic areas or in the society. (2 figs, 1 tab)
Advertising, marketing and purchase behavior for energy-related products
Energy Technology Data Exchange (ETDEWEB)
Tiedemann, K.; Nelson, D.
1998-07-01
Energy conservation programs have relied heavily on incentives and regulatory standards to reduce residential energy consumption. However, in the changing market environment characterized by competitive pressures, alternative mechanisms such as marketing and promotions may increase substantially in importance compared to the demand-side management programs which have been the focus of most research. This paper describes the role of marketing and promotions in encouraging energy efficiency at the household level in British Columbia. The paper examines three related issues: first, the purchase process for energy-related products; second, the criteria used by customers in making purchase decisions; and third, the impact and effectiveness of alternative marketing tools. A key finding is the energy-related purchases do not fall into the impulse purchase category. There are two reasons for this: first, most of these products require installation and this requires a high level of commitment on the part of the purchaser; second, many energy-related products require a significant outlay of funds and this reduces impulse buying.
An attempt to assess the energy related climate variability
Energy Technology Data Exchange (ETDEWEB)
Iotova, A [Bulgarian Academy of Sciences, Sofia (Bulgaria). National Inst. of Meteorology and Hydrology
1996-12-31
A lot of efforts are directed now to study the interactions between energy and climate because of their significant importance for our planet. Globally, energy related emissions of Greenhouse Gases (GHGs) contribute for atmospheric warming. On regional level, where it is more difficult to determine concrete direction of climate variability and change, the role of energy remains considerable being not so direct as in the case of emissions` impact. Still there is essential necessity for further analyses and assessments of energy related climate variations and change in order to understand better and to quantify the energy - climate relations. In the presentation an attempt is made to develop approach for assessment of energy related climate variations on regional level. For this purpose, data and results from the research within Bulgarian Case Study (BCS) in the DECADES Inter-Agency Project framework are used. Considering the complex nature of the examined interconnections and the medium stage of the Study`s realisation, at the moment the approach can be presented in conceptual form. Correspondingly, the obtained results are illustrative and preliminary
An attempt to assess the energy related climate variability
Energy Technology Data Exchange (ETDEWEB)
Iotova, A. [Bulgarian Academy of Sciences, Sofia (Bulgaria). National Inst. of Meteorology and Hydrology
1995-12-31
A lot of efforts are directed now to study the interactions between energy and climate because of their significant importance for our planet. Globally, energy related emissions of Greenhouse Gases (GHGs) contribute for atmospheric warming. On regional level, where it is more difficult to determine concrete direction of climate variability and change, the role of energy remains considerable being not so direct as in the case of emissions` impact. Still there is essential necessity for further analyses and assessments of energy related climate variations and change in order to understand better and to quantify the energy - climate relations. In the presentation an attempt is made to develop approach for assessment of energy related climate variations on regional level. For this purpose, data and results from the research within Bulgarian Case Study (BCS) in the DECADES Inter-Agency Project framework are used. Considering the complex nature of the examined interconnections and the medium stage of the Study`s realisation, at the moment the approach can be presented in conceptual form. Correspondingly, the obtained results are illustrative and preliminary
Chizhik, Stanislav; Sidelnikov, Anatoly; Zakharov, Boris; Naumov, Panče; Boldyreva, Elena
2018-02-28
Photomechanically reconfigurable elastic single crystals are the key elements for contactless, timely controllable and spatially resolved transduction of light into work from the nanoscale to the macroscale. The deformation in such single-crystal actuators is observed and usually attributed to anisotropy in their structure induced by the external stimulus. Yet, the actual intrinsic and external factors that affect the mechanical response remain poorly understood, and the lack of rigorous models stands as the main impediment towards benchmarking of these materials against each other and with much better developed soft actuators based on polymers, liquid crystals and elastomers. Here, experimental approaches for precise measurement of macroscopic strain in a single crystal bent by means of a solid-state transformation induced by light are developed and used to extract the related temperature-dependent kinetic parameters. The experimental results are compared against an overarching mathematical model based on the combined consideration of light transport, chemical transformation and elastic deformation that does not require fitting of any empirical information. It is demonstrated that for a thermally reversible photoreactive bending crystal, the kinetic constants of the forward (photochemical) reaction and the reverse (thermal) reaction, as well as their temperature dependence, can be extracted with high accuracy. The improved kinematic model of crystal bending takes into account the feedback effect, which is often neglected but becomes increasingly important at the late stages of the photochemical reaction in a single crystal. The results provide the most rigorous and exact mathematical description of photoinduced bending of a single crystal to date.
Pietropaolo, Antonino; Andreani, Carla; Filabozzi, Alessandra; Senesi, Roberto; Gorini, Giuseppe; Perelli-Cippo, Enrico; Tardocchi, Marco; Rhodes, Nigel J.; Schooneveld, Erik M.
2006-04-01
Deep Inelastic Neutron Scattering (DINS) measurements have been performed on a liquid water sample at two different temperatures and pressures. The experiments were carried out using the VESUVIO spectrometer at the ISIS spallation neutron source. This experiment represents the first DINS measurement from water using the Resonance Detector configuration, employing yttrium-aluminum-perovskite scintillator and a 238U analyzer foil. The maximum energy of the scattered neutrons was about 70 eV, allowing to access an extended kinematic space with energy and wave vector transfers at the proton recoil peak in the range 1 eV <= hbarω <= 20 eV and 25 Å-1 <= q <= 90 Å-1, respectively. Comparison with DINS measurements on water performed in the standard Resonance Filter configuration indicates the potential advantages offered by the use of Resonance Detector approach for DINS measurements at forward scattering angles.
Nonlinear generalization of special relativity at very high energies
International Nuclear Information System (INIS)
Winterberg, F.
1984-01-01
It is shown, that the introduction of a fundamental length constant into the operator representation of the quantum mechanical commutation relations, as suggested by Bagge, leads to a nonlinear generalization of the Lorentz transformations. The theory requires the introduction of a substratum (ether) and which can be identified as the zero point vacuum energy. At very high energies a non-Lorentz invariant behaviour for the cross sections between elementary particles is predicted. Using the Einstein clock synchronisation definition, the velocity of light is also constant and equal to c in the new theory, but the zero point vacuum energy becomes finite, as are all other quantities which are divergent in Lorentz invariant quantum field theories. In the limiting case where the length constant is set equal to zero, the zero point vacuum energy diverges and special relativity is recovered. (orig.) [de
International Nuclear Information System (INIS)
Puddu, Pierpaolo; Paderi, Maurizio
2013-01-01
In this work the differences between the thermodynamic behaviour of real and ideal gases are analysed to determine their influence on the processes of compression and expansion of a gas-charged accumulator. The behaviour of real gas has a significant influence on the size of accumulators used for Kinetic Energy Recovery of vehicles. In particular, it is underscored that the accumulator's design, based on ideal gas behaviour, provides undersized accumulators and therefore makes impossible the complete energy recovery for Hydraulic Energy Storage Systems (HES). The analysis of the thermodynamic properties of gases has shown that the main differences between ideal and real behaviour are due to gas compressibility. A mathematical model of a gas-charged accumulator is developed in order to analyse its real behaviour in presence of irreversible heat transfer and viscous losses. The simulation process of charging and discharging of a hydro-pneumatic accumulator, makes it clear that hydrodynamic and thermal losses are responsible for the characteristic hysteresis cycle on the p–V diagram. Different gases are tested as charged fluid of a hydro-pneumatic accumulator to simulate cyclic processes of charge and discharge. Results show different characteristics in terms of volumetric gas properties, thermal time-constant and thermal efficiency of the accumulator. - Highlights: • A dynamic model of a gas charged accumulator was developed. • Gas compressibility significantly influences the size of high-pressure accumulators. • A hysteresis loop is indicative of the thermal energy losses. • Loss increases with increasing the period of the cyclic process. • Thermal time constant is different from compression to expansion
Adamovich, Igor V; Li, Ting; Lempert, Walter R
2015-08-13
This work describes the kinetic mechanism of coupled molecular energy transfer and chemical reactions in low-temperature air, H2-air and hydrocarbon-air plasmas sustained by nanosecond pulse discharges (single-pulse or repetitive pulse burst). The model incorporates electron impact processes, state-specific N(2) vibrational energy transfer, reactions of excited electronic species of N(2), O(2), N and O, and 'conventional' chemical reactions (Konnov mechanism). Effects of diffusion and conduction heat transfer, energy coupled to the cathode layer and gasdynamic compression/expansion are incorporated as quasi-zero-dimensional corrections. The model is exercised using a combination of freeware (Bolsig+) and commercial software (ChemKin-Pro). The model predictions are validated using time-resolved measurements of temperature and N(2) vibrational level populations in nanosecond pulse discharges in air in plane-to-plane and sphere-to-sphere geometry; temperature and OH number density after nanosecond pulse burst discharges in lean H(2)-air, CH(4)-air and C(2)H(4)-air mixtures; and temperature after the nanosecond pulse discharge burst during plasma-assisted ignition of lean H2-mixtures, showing good agreement with the data. The model predictions for OH number density in lean C(3)H(8)-air mixtures differ from the experimental results, over-predicting its absolute value and failing to predict transient OH rise and decay after the discharge burst. The agreement with the data for C(3)H(8)-air is improved considerably if a different conventional hydrocarbon chemistry reaction set (LLNL methane-n-butane flame mechanism) is used. The results of mechanism validation demonstrate its applicability for analysis of plasma chemical oxidation and ignition of low-temperature H(2)-air, CH(4)-air and C(2)H(4)-air mixtures using nanosecond pulse discharges. Kinetic modelling of low-temperature plasma excited propane-air mixtures demonstrates the need for development of a more accurate
The psychosocial and behavioral characteristics related to energy misreporting.
Maurer, Jaclyn; Taren, Douglas L; Teixeira, Pedro J; Thomson, Cynthia A; Lohman, Timothy G; Going, Scott B; Houtkooper, Linda B
2006-02-01
Energy underreporting occurs in 2% to 85% and overreporting in 1% to 39% of various populations. Efforts are needed to understand the psychosocial and behavioral characteristics associated with misreporting to help improve the accuracy of dietary self-reporting. Past research suggests that higher social desirability and greater eating restraint are key factors influencing misreporting, while a history of dieting and being overweight are more moderately associated. Eating disinhibition, body image, depression, anxiety, and fear of negative evaluation may be related to energy misreporting, but evidence is insufficient. This review will provide a detailed discussion of the published associations among psychosocial and behavioral characteristics and energy misreporting.
Implicit ligand theory for relative binding free energies
Nguyen, Trung Hai; Minh, David D. L.
2018-03-01
Implicit ligand theory enables noncovalent binding free energies to be calculated based on an exponential average of the binding potential of mean force (BPMF)—the binding free energy between a flexible ligand and rigid receptor—over a precomputed ensemble of receptor configurations. In the original formalism, receptor configurations were drawn from or reweighted to the apo ensemble. Here we show that BPMFs averaged over a holo ensemble yield binding free energies relative to the reference ligand that specifies the ensemble. When using receptor snapshots from an alchemical simulation with a single ligand, the new statistical estimator outperforms the original.
Nano crystals-Related Synthesis, Assembly, and Energy Applications 2012
International Nuclear Information System (INIS)
Zou, B.; Yu, W.W.; Seo, J.; Zhu, T.; Hu, M.Z.
2012-01-01
During the past decades, nano crystals have attracted broad attention due to their unique shape- and size-dependent physical and chemical properties that differ drastically from their bulk counterparts. Hitherto, much effort has been dedicated to achieving rational controlling over the morphology, assembly, and related energy applications of the nano materials. Therefore, the ability to manipulate the morphology, size, and size distribution of inorganic nano materials is still an important goal in modern materials physics and chemistry. Especially, the world's demand for energy supply is causing a dramatic escalation of social and political unrest. Likewise, the environmental impact of the global climate change due to the combustion of fossil fuel is becoming increasingly alarming. These problems compel us to search for effective routes to build devices that can supply sustainable energy, with not only high efficiency but also environmental friendship. One of ways to relieve the energy crisis is to exploit devices based on renewable energy sources, such as solar energy and water power. Aiming at this exploration, the primary stage requires the design of appropriate strategies for the synthesis of high-quality nano crystals with respect to size uniformity and superior electrochemical performances. As a consequence, we organize the current special issue for Journal of Nano materials to provide the authors with a platform and readers with the latest achievements of nano crystals-related synthesis, assembly, and energy applications.
Onwude, Daniel I.; Hashim, Norhashila; Abdan, Khalina; Janius, Rimfiel; Chen, Guangnan
2018-04-01
This study investigated the drying kinetics, mass and heat transfer characteristics of sweet potato slices (0.4-0.6 cm thickness) during drying based on mid-infrared experimental set-up (intensity of 1100-1400 W/m2). Thin layer drying models were used to evaluate the drying kinetics of sweet potato slices. Two analytical models (Fick's diffusion model, and Dincer and Dost model) were used to study the mass transfer behaviour of sweet potato slices with and without shrinkage during mid-infrared drying. The heat transfer flux between the emitter and sweet potato slices was also investigated. Results demonstrated that an increase in infrared intensity from 1100 W/m2 to 1400 W/m2 resulted in increased in average radiation heat flux by 3.4 times and a 15% reduction in the overall drying time. The two-term exponential model was found to be the best in predicting the drying kinetics of sweet potato slices during mid-infrared drying. The specific heat consumption varied from 0.91-4.82 kWh/kg. The effective moisture diffusivity with and without shrinkage using the Fick's diffusion model varied from 2.632 × 10-9 to 1.596 × 10-8 m2/s, and 1.24 × 10-8 to 2.4 × 10-8 m2/s using Dincer and Dost model, respectively. The obtained values of mass transfer coefficient, Biot number and activation energy varied from 5.99 × 10-6 to 1.17 × 10-5 m/s, 0.53 to 2.62, and 12.83 kJ/mol to 34.64 kJ/mol, respectively. The values obtained for Biot number implied the existence of simultaneous internal and external resistances. The findings further explained that mid-infrared intensity of 1100 W/m2 did not significantly affect the quality of sweet potato during drying, demonstrating a great potential of applying low intensity mid-infrared radiation in the drying of agricultural crops.
International Nuclear Information System (INIS)
2002-01-01
The main goals of the majority of processes and developments relating to energy sectors of today present the enhancement of energy sector efficiency, ensuring of stable financial sources and safe return of the means invested through practice of activities at the market of energy and energy services, i.e. public services or monopoly. This is to be achieved by means of energy sector restructuring and liberalisation, pluralism of ownership and transparency of the organisational and management scheme. Thereby, an important role and significance for the realisation of these aims, for the development and energy market functioning on the national level, as well as for the achievement of reciprocity and complementarity of national markets with regional and multi-national energy markets, is held by models and forms of energy activity regulation. In a limited sense, the regulation itself should constitute an adequate stimulating framework for free energy flows, transparent and non- discriminating conditions for the utilisation of transmission and transportation systems and networks, protection of supplier choice rights, pluralism of ownership and ownership rights, protection of energy and energy services' quality, environmental protection, protection of purchasers and consumers and protection of energy subjects. For all these reasons, aspects and problems appertaining to energy sector and energy activities' regulation have been chosen as the theme and contents of the 11th Forum. Various countries have undertaken and implemented or are in the process of implementation of different models and contents referring to energy sector and energy activity regulation. Experience and legislative practice are quoted as the main criteria. The aim of this Forum is to set forth and clarify experiences and solutions connected to the regulation of energy activities in numerous European countries or in the world
Garraffo, Zulema; Garzoli, Silvia L.; Haxby, William; Olson, Donald
1992-01-01
It was found (Garzoli et al., 1992) that the general circulation model of Semtner and Chervin (1992) provides accurate descriptions of the Brazil-Malvinas and the Kuroshio/Oyashio confluence systems, except for the fact that the model prediction shows less variability than that present in observations. This paper investigates the problem of model variability by analyzing the mean and the eddy kinetic energy from the model and comparing the values with the Geosat altimeter observations for the South Atlantic Ocean and for the Kuroshio system. It is found that, while the model shows transient eddy activity in the areas that overlap the Geosat observations, the energy level of the model transient motions is considerably smaller following an arch along the bottom topography. The same was found from the comparisons made with values obtained from FGGE and surface drifters. It is suggested that the model is poorly resolving instabilities in the confluence front, and is not resolving other transients appearing in regions of marked topography.
Goh, J. B.; Jamaludin, Z.; Jafar, F. A.; Mat Ali, M.; Mokhtar, M. N. Ali; Tan, C. H.
2017-06-01
Wasted kinetic energy recovery system (WKERS) is a wind renewable gadget installed above a cooling tower outlet to harvest the discharged wind for electrical regeneration purpose. The previous WKERS is operated by a horizontal axis wind turbine (HAWT) with delta blade design but the performance is still not at the optimum level. Perhaps, a better blade-shape design should be determined to obtain the optimal performance, as it is believed that the blade-shape design plays a critical role in HAWT. Hence, to determine a better blade-shape design for a new generation of WKERS, elliptical blade, swept blade and NREL Phase IV blade are selected for this benchmarking process. NREL Phase IV blade is a modern HAWT’s blade design by National Renewable Energy Laboratory (NREL) research lab. During the process of benchmarking, Computational Fluid Dynamics (CFD) analysis was ran by using SolidWorks design software, where all the designs are simulated with linear flow simulation. The wind speed in the simulation is set at 10.0 m/s, which is compatible with the average wind speed produced by a standard size cooling tower. The result is obtained by flow trajectories of air motion, surface plot and cut plot of the applied blade-shape. Besides, the aspect ratio of each blade is calculated and included as one of the reference in the comparison. Hence, the final selection of the best blade-shape design will bring to the new generation of WKERS.
International Nuclear Information System (INIS)
Fujii, Keisuke; Mizushiri, Keisuke; Nishioka, Tomomi; Shikama, Taiichi; Iwamae, Atsushi; Goto, Motoshi; Morita, Shigeru; Hasuo, Masahiro
2010-01-01
We have simultaneously measured high resolution emission spectra of the hydrogen atomic Balmer-α, -β, -γ lines and molecular Fulcher-α band for a LHD peripheral plasma generated under a central magnetic field strength of 0.4 T. It is found that the velocity distributions of excited atoms calculated from the Balmer-α, -β, and -γ line shapes show similar profiles to each other. The translational kinetic energy corresponding to the average velocity is about 13 eV, which is about 300 times larger than the rotational energy of hydrogen molecules estimated from the line intensities in the Fulcher-α band. The velocity distributions differ from Maxwellian and have a high velocity tail over 1x10 5 m/s. A correlation between the high velocity tail and the electron temperature and density is seen and suggesting the excited atoms having such high velocities to be generated by the charge exchange collisions from high velocity protons in the peripheral region.
The EU Integration Discourse in the Energy Relations with Russia
Directory of Open Access Journals (Sweden)
Tichý Lukáš
2016-01-01
Full Text Available The energy issue is a long-term one of the most discussed, controversial topics in relations between the European Union and the Russian Federation. The intention of the present article is an attempt to overcome the largely non-discursive and in the security conditions anchored way of looking at the energy interaction of the EU and the RF and through an integration discourse to analyze EU energy relations with Russia in the years 2004 - 2014. In the theoretical level, the article is based on a critical constructivism, which in relation to the discourse as the main concept reflects a number of fundamental knowledge. At the methodological level, the article is based on the discourse analysis as a basic methodological tool through which the author examines the EU text documents.
Hartogensis, O.K.; Debruin, H.A.R.
2005-01-01
The Monin-Obukhov similarity theory (MOST) functions fepsi; and fT, of the dissipation rate of turbulent kinetic energy (TKE), ¿, and the structure parameter of temperature, CT2, were determined for the stable atmospheric surface layer using data gathered in the context of CASES-99. These data cover
Long term energy-related environmental issues of copper production
Energy Technology Data Exchange (ETDEWEB)
Alvarado, S. [University of Chile, Santiago (Chile). Dept. of Mechanical Engineering; Maldonado, P.; Barrios, A.; Jaques, I. [University of Chile, Santiago (Chile). Energy Research Program
2002-02-01
Primary copper production is a major activity in the mining sector of several countries. However, it is highly energy-intensive and poses important environmental hazards. In the case of Chile, the world's largest copper producer (40% of world total), we examine its energy consumption and energy-related environmental implications over a time horizon of 25 years. Concerning the latter, we focus on greenhouse-gas (GHG) emissions, one of the most debated environmental issues. This paper follows up our previous report in which the current situation was analyzed and a particular technical option for improving the energy efficiency and concurrently reducing GHG emissions was discussed. Estimated reference or base (BS) and mitigation (MS) scenarios are developed for the period ending in 2020. The former assesses the energy demand projected in accordance with production forecasts and specific energy consumption patterns (assuming that energy efficiency measures are adopted 'spontaneously') with their resultant GHG emissions, while the latter assumes induced actions intended to reduce emissions by adopting an aggressive policy of efficient energy use. For the year 2020, the main results are: (i) BS, 1214 t of CO{sub 2}/ton of refined copper content (49% lower than in 1994); (ii) MS, 1037 t of CO{sub 2}/t of refined copper content (56% lower than in 1994). CO{sub 2} emissions have been estimated considering both fuel and electricity process requirements. (author)
Long term energy-related environmental issues of copper production
International Nuclear Information System (INIS)
Alvarado, S.; Maldonado, P.; Barrios, A.; Jaques, I.
2002-01-01
Primary copper production is a major activity in the mining sector of several countries. However, it is highly energy-intensive and poses important environmental hazards. In the case of Chile, the world's largest copper producer (40% of world total), we examine its energy consumption and energy-related environmental implications over a time horizon of 25 years. Concerning the latter, we focus on greenhouse-gas (GHG) emissions, one of the most debated environmental issues. This paper follows up our previous report in which the current situation was analyzed and a particular technical option for improving the energy efficiency and concurrently reducing GHG emissions was discussed. Estimated reference or base (BS) and mitigation (MS) scenarios are developed for the period ending in 2020. The former assesses the energy demand projected in accordance with production forecasts and specific energy consumption patterns (assuming that energy efficiency measures are adopted 'spontaneously') with their resultant GHG emissions, while the latter assumes induced actions intended to reduce emissions by adopting an aggressive policy of efficient energy use. For the year 2020, the main results are: (i) BS, 1214 t of CO 2 /ton of refined copper content (49% lower than in 1994); (ii) MS, 1037 t of CO 2 /t of refined copper content (56% lower than in 1994). CO 2 emissions have been estimated considering both fuel and electricity process requirements. (author)
Relative energy for the Korteweg theory and related Hamiltonian flows in gas dynamics
Giesselmann, Jan
2016-10-26
For an Euler system, with dynamics generated by a potential energy functional, we propose a functional format for the relative energy and derive a relative energy identity. The latter, when applied to specific energies, yields relative energy identities for the Euler-Korteweg, the Euler-Poisson, the Quantum Hydrodynamics system, and low order approximations of the Euler-Korteweg system. For the Euler-Korteweg system we prove a stability theorem between a weak and a strong solution and an associated weak-strong uniqueness theorem. In the second part we focus on the Navier-Stokes-Korteweg system (NSK) with non-monotone pressure laws: we prove stability for the NSK system via a modified relative energy approach. We prove continuous dependence of solutions on initial data and convergence of solutions of a low order model to solutions of the NSK system. The last two results provide physically meaningful examples of how higher order regularization terms enable the use of the relative energy framework for models with energies which are not poly- or quasi-convex, but compensating via higher-order gradients.
Constraints on stress-energy perturbations in general relativity
International Nuclear Information System (INIS)
Traschen, J.
1985-01-01
Conditions are found for the existence of integral constraints on stress-energy perturbations in general relativity. The integral constraints can be thought of as a general-relativistic generalization of the conservation of energy and momentum of matter perturbations in special relativity. The constraints are stated in terms of a vector field V, and the Robertson-Walker spacetimes are shown to have such constraint vectors. Although in general V is not a Killing vector, in a vacuum spacetime the constraint vectors are precisely the Killing vectors
Approximate theory the electromagnetic energy of solenoid in special relativity
International Nuclear Information System (INIS)
Prastyaningrum, I; Kartikaningsih, S.
2017-01-01
Solenoid is a device that is often used in electronic devices. A solenoid is electrified will cause a magnetic field. In our analysis, we just focus on the electromagnetic energy for solenoid form. We purpose to analyze by the theoretical approach in special relativity. Our approach is begun on the Biot Savart law and Lorentz force. Special theory relativity can be derived from the Biot Savart law, and for the energy can be derived from Lorentz for, by first determining the momentum equation. We choose the solenoid form with the goal of the future can be used to improve the efficiency of the electrical motor. (paper)
Intelligent structures and design of energy related facilities
International Nuclear Information System (INIS)
Namba, Haruyuki
1994-01-01
Possibility of applying intelligent structural concepts to civil design of energy plants is discussed. Intelligent structures, which are now common in aerospace engineering field, are also referred to as adaptive structures or smart structures depending on cases. Among various existing concepts, reconfigurable structures, precise shape control, structural monitoring using smart materials of optical fiber sensors, and relation with recent innovative communication technologies are focused from civil engineering point of view. Application of such new technologies will help to enhance design of energy related plants, which include multiplex functions which need to be very reliable and safe. (author)
Yu, Iris K M; Tsang, Daniel C W; Yip, Alex C K; Chen, Season S; Wang, Lei; Ok, Yong Sik; Poon, Chi Sun
2017-08-01
This study aimed to maximize the valorization of bread waste, a typical food waste stream, into hydroxymethylfurfural (HMF) by improving our kinetic understanding. The highest HMF yield (30mol%) was achieved using SnCl 4 as catalyst, which offered strong derived Brønsted acidity and moderate Lewis acidity. We evaluated the kinetic balance between these acidities to facilitate faster desirable reactions (i.e., hydrolysis, isomerization, and dehydration) relative to undesirable reactions (i.e., rehydration and polymerization). Such catalyst selectivity of SnCl 4 , AlCl 3 , and FeCl 3 was critical in maximizing HMF yield. Higher temperature made marginal advancement by accelerating the undesirable reactions to a similar extent as the desirable pathways. The polymerization-induced metal-impregnated high-porosity carbon was a possible precursor of biochar-based catalyst, further driving up the economic potential. Preliminary economic analysis indicated a net gain of USD 43-236 per kilogram bread waste considering the thermochemical-conversion cost and chemical-trading revenue. Copyright © 2017 Elsevier Ltd. All rights reserved.
Yu, Kai; Dong, Changming; King, Gregory P.
2017-06-01
We investigate mesoscale turbulence (10-1000 km) in the ocean winds over the Kuroshio Extension (28°N-40°N, 140°E-180°E) using the QuikSCAT data set (November 1999 to October 2009). We calculate the second (Djj) and third-order structure functions (Djjj) and the spatial variance (Vj) as a function of scale r (j=L,T denotes, respectively, the longitudinal (divergent) and transverse (vortical) component). The most interesting results of the analysis follow. Although both Vj>(r>) and Djj>(r>) measure the turbulent kinetic energy (TKE), we find that Vj>(r>) is the more robust measure. The spatial variance density (dVj/dr) has a broad peak near 450 km (close to the midlatitude Rossby radius of deformation). On interannual time scales, TKE correlates well with the El Niño 3.4 index. According to turbulence theory, the kinetic energy cascades downscale (upscale) if DLLL>(r>) (also skewness SL=DLLL/DLL3/2) is negative (positive). Our results for the Kuroshio Extension are consistent with a downscale cascade (indicating convergence dominates). Furthermore, classical turbulence theory predicts that SL=-0.3 and independent of r; however, we find SL varies strongly with r, from -4 at small scales to -0.3 at large scales. This nonclassical behavior implies strong-scale interaction, which we attribute to the rapid, and sometimes explosive, growth of storms in the region through baroclinic instability. Finally, we find that ST (a measure of cyclonic/anticyclonic asymmetry) is positive (cyclonic) and also varies strongly with r, from 4 at small scales to 0.5 at large scales. New turbulence models are needed to explain these results, and that will benefit Weather Prediction and climate modeling.Plain Language SummaryThe turbulent winds near the ocean surface give rise to air-sea heat and momentum exchange. The turbulence is caused by convective processes - processes generated at weather fronts, in squalls, tropical disturbances and extra-tropical cyclones. In order to improve
International Nuclear Information System (INIS)
Keszenman, D.J.; Sutherland, B.M.
2010-01-01
To determine the linear energy transfer (LET) dependence of the biological effects of densely ionizing radiation in relation to changes in the ionization density along the track, we measured the yields and spectrum of clustered DNA damages induced by charged particles of different atomic number but similar kinetic energy per nucleon in different DNA microenvironments. Yeast DNA embedded in agarose in solutions of different free radical scavenging capacity was irradiated with 1 GeV protons, 1 GeV/nucleon oxygen ions, 980 MeV/nucleon titanium ions or 968 MeV/nucleon iron ions. The frequencies of double-strand breaks (DSBs), abasic sites and oxypurine clusters were quantified. The total DNA damage yields per absorbed dose induced in non-radioquenching solution decreased with LET, with minor variations in radioquenching conditions being detected. However, the total damage yields per particle fluence increased with LET in both conditions, indicating a higher efficiency per particle to induce clustered DNA damages. The yields of DSBs and non-DSB clusters as well as the damage spectra varied with LET and DNA milieu, suggesting the involvement of more than one mechanism in the formation of the different types of clustered damages.
Kinetic energy density and agglomerate abrasion rate during blending of agglomerates into powders
Willemsz, T.A.; Hooijmaijers, R.; Rubingh, C.M.; Tran, T.N.; Frijlink, H.W.; Vromans, H.; Maarschalk, K.V.D.V.
2012-01-01
Problems related to the blending of a cohesive powder with a free flowing bulk powder are frequently encountered in the pharmaceutical industry. The cohesive powder often forms lumps or agglomerates which are not dispersed during the mixing process and are therefore detrimental to blend uniformity.
Relation of wave energy and momentum with the plasma dispersion relation in an inhomogeneous plasma
International Nuclear Information System (INIS)
Berk, H.L.; Pfirsch, D.
1988-01-01
The expressions for wave energy and angular momentum commonly used in homogeneous and near-homogeneous media is generalized to inhomogeneous media governed by a nonlocal conductivity tensor. The expression for wave energy applies to linear excitations in an arbitrary three-dimensional equilibrium, while the expression for angular momentum applies to linear excitations of azimuthally symmetric equilibria. The wave energy E-script/sub wave/ is interpreted as the energy transferred from linear external sources to the plasma if there is no dissipation. With dissipation, such a simple interpretation is lacking as energy is also thermally absorbed. However, for azimuthally symmetric equilibria, the expression for the wave energy in a frame rotating with a frequency ω can be unambiguously separated from thermal energy. This expression is given by E-script/sub wave/ -ωL/sub wave/ l, where L/sub wave/ is the wave angular momentum defined in the text and l the azimuthal wavenumber and it is closely related to the real part of a dispersion relation for marginal stability. The imaginary part of the dispersion is closely related to the energy input into a system. Another useful quantity discussed is the impedance form, which can be used for three-dimensional equilibrium without an ignorable coordinate and the expression is closely related to the wave impedance used in antenna theory. Applications to stability theory are also discussed
Jiang, Chuanjia; Castellon, Benjamin T.; Matson, Cole W.; Aiken, George R.; Hsu-Kim, Heileen
2017-01-01
The toxicity of soluble metal-based nanomaterials may be due to the uptake of metals in both dissolved and nanoparticulate forms, but the relative contributions of these different forms to overall metal uptake rates under environmental conditions are not quantitatively defined. Here, we investigated the linkage between the dissolution rates of copper(II) oxide (CuO) nanoparticles (NPs) and their bioavailability to Gulf killifish (Fundulus grandis) embryos, with the aim of quantitatively delineating the relative contributions of nanoparticulate and dissolved species for Cu uptake. Gulf killifish embryos were exposed to dissolved Cu and CuO NP mixtures comprising a range of pH values (6.3–7.5) and three types of natural organic matter (NOM) isolates at various concentrations (0.1–10 mg-C L–1), resulting in a wide range of CuO NP dissolution rates that subsequently influenced Cu uptake. First-order dissolution rate constants of CuO NPs increased with increasing NOM concentration and for NOM isolates with higher aromaticity, as indicated by specific ultraviolet absorbance (SUVA), while Cu uptake rate constants of both dissolved Cu and CuO NP decreased with NOM concentration and aromaticity. As a result, the relative contribution of dissolved Cu and nanoparticulate CuO species for the overall Cu uptake rate was insensitive to NOM type or concentration but largely determined by the percentage of CuO that dissolved. These findings highlight SUVA and aromaticity as key NOM properties affecting the dissolution kinetics and bioavailability of soluble metal-based nanomaterials in organic-rich waters. These properties could be used in the incorporation of dissolution kinetics into predictive models for environmental risks of nanomaterials.
Lee, Ying Ping; Fujii, Manabu; Kikuchi, Tetsuro; Terao, Koumei; Yoshimura, Chihiro
2017-01-01
Oxidation and reduction kinetics of iron (Fe) and proportion of steady-state Fe(II) concentration relative to total dissolved Fe (steady-state Fe(II) fraction) were investigated in the presence of various types of standard humic substances (HS) with particular emphasis on the photochemical and thermal reduction of Fe(III) and oxidation of Fe(II) by dissolved oxygen (O2) and hydrogen peroxide (H2O2) at circumneutral pH (pH 7-8). Rates of Fe(III) reduction were spectrophotometrically determined by a ferrozine method under the simulated sunlight and dark conditions, whereas rates of Fe(II) oxidation were examined in air-saturated solution using luminol chemiluminescence technique. The reduction and oxidation rate constants were determined to substantially vary depending on the type of HS. For example, the first-order rate constants varied by up to 10-fold for photochemical reduction and 7-fold for thermal reduction. The degree of variation in Fe(II) oxidation was larger for the H2O2-mediated reaction compared to the O2-mediated reaction (e.g., 15- and 3-fold changes for the former and latter reactions, respectively, at pH 8). The steady-state Fe(II) fraction under the simulated sunlight indicated that the Fe(II) fraction varies by up to 12-fold. The correlation analysis indicated that variation of Fe(II) oxidation is significantly associated with aliphatic content of HS, suggesting that Fe(II) complexation by aliphatic components accelerates Fe(II) oxidation. The reduction rate constant and steady-state Fe(II) fractions in the presence of sunlight had relatively strong positive relations with free radical content of HS, possibly due to the reductive property of radical semiquinone in HS. Overall, the findings in this study indicated that the Fe reduction and oxidation kinetics and resultant Fe(II) formation are substantially influenced by chemical properties of HS.
Energy-Transfer Kinetics for Xe (6p[1/2]0) Atoms in Kr, Ar, Ne, and He.
He, Shan; Liu, Dong; Li, Xueyang; Chu, Junzhi; Guo, Jingwei; Liu, Jinbo; Hu, Shu; Sang, Fengting; Jin, Yuqi
2018-06-11
The kinetic processes for the Xe (6p[1/2] 0 ) atoms in Kr, Ar, Ne, and He buffer gases were studied. We found that Kr, Ar, and Ne atoms can be used to switch the amplified spontaneous emission (ASE) channel from 3408 nm (6p[1/2] 0 -6s'[1/2] 1 ) to 3680 nm (5d[1/2] 1 -6p[1/2] 1 ), while Xe and He atoms do not show such a phenomenon. This ASE channel switch is mainly ascribed to the fast transfer of 6p[1/2] 0 → 5d[1/2] 1 . On the basis of the rate equations for two-state coupling (energy-transfer processes between the two states are very rapid), the reason why the ASE channel switch effect normally coincides with a double exponential decay of the spontaneous emission at 828 nm (6p[1/2] 0 -6s[3/2] 1 ) is explained. The actual situations in Xe, Ar, Ne, and He follow this rule. However, the strictly single exponential decay of the spontaneous emission at 828 nm and strong ASE channel switch effect simultaneously emerge in Kr. This indicates that the transfer of 6p[1/2] 0 → 5d[1/2] 1 in Kr does not occur via two-state coupling, but via two steps of near-resonance collision through the 5s[3/2] 2 (Kr) state as the intermediate state (6p[1/2] 0 → 5s[3/2] 2 (Kr) → 5d[1/2] 1 ). In addition, we found Xe (6p[1/2] 0 ) atoms strongly tend to reach the 6p[3/2] 2 , 6p[3/2] 1 , and 6p[5/2] 2 states through the 5s[3/2] 2 (Kr) state as the intermediate state in Kr. The 5s[3/2] 2 (Kr) state plays a very important role in the energy-transfer kinetics for the Xe (6p[1/2] 0 ) atoms. Kr is probably an excellent buffer gas for laser systems based on Xe.
The relation between food price, energy density and diet quality
Directory of Open Access Journals (Sweden)
Margareta Bolarić
2013-01-01
Full Text Available Low energy density diet, high in fruits and vegetables, is related to lower obesity risk and to better health status, but is more expensive. High energy density diet, high in added sugar and fats, is more affordable, but is related to higher obesity and chronic diseases risk. The aim of this study was to report prices according to energy density (low vs. high of food items and to show how food affordability could affect food choice and consumers’ health. Data was collected for 137 raw and processed foods from three purchase sites in Zagreb (one representative for supermarket, one smaller shop and green market. Results showed that low energy density food is more expensive than high energy density food (for example, the price of 1000 kcal from green zucchini (15 kcal/100 g is 124.20 kn while the price of 1000 kcal from sour cream (138 kcal/100 g is 13.99 kn. Food energy price was significantly different (p<0.05 between food groups with highest price for vegetable products (159.04 ± 36.18 kn/1000 kcal and raw vegetables (97.90 ± 50.13 kn/1000 kcal and lowest for fats (8.49 ± 1.22 kn/1000 kcal and cereals and products (5.66 ± 0.76 kn/1000 kcal. Negative correlation (Spearman r=-0.72, p<0.0001 was observed for energy density (kcal/100 g and price of 1000 kcal. Therefore, it is advisable to develop strategies in order to reduce price of low energy density food and encourage its intake since it would improve diet quality, which could lead to better costumers’ health.
Take-Off Efficiency: Transformation of Mechanical Work Into Kinetic Energy During the Bosco Test
Directory of Open Access Journals (Sweden)
Jandova Sona
2017-09-01
Full Text Available Purpose. The aim of the study is to present a new method for determining the efficiency of take-off during a 60-s Bosco repeated vertical jump test. Method. The study involved 15 physical education students (age: 21.5 ± 2.4 years; height: 1.81 ± 0.08 m; mass: 76 ± 9 kg. The data were collected with the use of a pedobarographical system (Pedar-x; Novel, Munich, Germany. The statistical analysis utilized a simple linear regression model. Results. Owing to possible fatigue, flight time and flight height decreased. The average flight height was 0.260 ± 0.063 m, and the average contact time equalled 0.54 ± 0.16 s. The average anaerobic power values calculated for the 60-s work period had the mean value of 21.9 ± 6.7 W · kgBW-1; there was a statistically significant (p < 0.05 decrease in anaerobic power during the 60-s Bosco test. Conclusions. The efficiency of mechanical work was highest at the beginning of the test, reaching values of up to 50%. The efficiency of mechanical work conversion into mechanical energy seems to be an appropriate determinant of rising fatigue during the 60-s Bosco jumping test.
International Nuclear Information System (INIS)
Gritsenko, I.A.; Klokol, K.A.; Sokolov, S.S.; Sheshin, G.A.
2016-01-01
An experimental study is made of the drag coefficient, which is the characteristics of energy dissipation during oscillations of the tuning forks, immersed in liquid helium. The experiments were performed in the temperature range from 0.1 to 3.5 K covering both the range of a hydrodynamic flow, and the ballistic regime of transfer of thermal excitations of superfluid helium below 0.6 K. It is found that there is the frequency dependence of the drag coefficient in the hydrodynamic limit, when the main dissipation mechanism is the viscous friction of the fluid against the walls of the oscillating body at temperatures above 0.7 K. In this case, the drag coefficient is proportional to the square root of the frequency of oscillation, and its temperature dependence in He II is determined by the respective dependence of the normal component density of the normal component and the viscosity of the fluid. At lower temperatures, the dependence of drag coefficient on the frequency is not available, and the magnitude of the dissipative losses is determined only by the temperature dependence of the density of the normal component. At the same time in the entire range of temperatures value of dissipative losses depends on the geometry of the oscillating body.
Goebel, Marc-O.; Woche, Susanne K.; Bachmann, Jörg
2012-06-01
SummaryAggregate stability is frequently shown to be enhanced by strong soil water repellency, however, there is limited systematic evidence on this effect for moderately (subcritically) water repellent soils. This study aimed to investigate the specific effects of interfacial properties on the liquid penetration kinetics in relation to the stability of subcritically water repellent aggregates (4-6.3 mm) from various arable and forest soils against breakdown by slaking. In contrast to many other studies, where aggregate stability was determined by wet sieving, we here assessed the stability by immersion of air-dry aggregates in water-ethanol solutions with surface tensions ranging from 30 to 70 mN m-1. This approach allowed a highly sensitive discrimination of different stability levels and the determination of breakdown kinetics also for less stable aggregates. Interfacial properties were characterized in terms of contact angle measured on crushed aggregates, θc, and calculated for intact aggregates, θi, based on infiltration measurements with water and ethanol. Aggregate stability turned out to be higher in forest soils compared to arable soils with topsoil aggregates generally found to be more stable than subsoil aggregates. For water repellent aggregates, characterized by contact angles >40° and low water infiltration rates (aggregates after 30 s of immersion was generally below 10%, whereas in case of the more wettable aggregates, characterized by contact angles 0.25 mm3 s-0.5) more than 80% of the aggregates were disrupted. In accordance, we found a close relationship between aggregate stability and wettability with differences between θc and θi being generally small. In addition, aggregate stability turned out to be related to organic carbon content. However, correlation analysis revealed that both persistence of aggregate stability and kinetics of aggregate breakdown were more strongly affected by the contact angle, θc (r = 0.90 and r = -0
Complex Hollow Nanostructures: Synthesis and Energy-Related Applications.
Yu, Le; Hu, Han; Wu, Hao Bin; Lou, Xiong Wen David
2017-04-01
Hollow nanostructures offer promising potential for advanced energy storage and conversion applications. In the past decade, considerable research efforts have been devoted to the design and synthesis of hollow nanostructures with high complexity by manipulating their geometric morphology, chemical composition, and building block and interior architecture to boost their electrochemical performance, fulfilling the increasing global demand for renewable and sustainable energy sources. In this Review, we present a comprehensive overview of the synthesis and energy-related applications of complex hollow nanostructures. After a brief classification, the design and synthesis of complex hollow nanostructures are described in detail, which include hierarchical hollow spheres, hierarchical tubular structures, hollow polyhedra, and multi-shelled hollow structures, as well as their hybrids with nanocarbon materials. Thereafter, we discuss their niche applications as electrode materials for lithium-ion batteries and hybrid supercapacitors, sulfur hosts for lithium-sulfur batteries, and electrocatalysts for oxygen- and hydrogen-involving energy conversion reactions. The potential superiorities of complex hollow nanostructures for these applications are particularly highlighted. Finally, we conclude this Review with urgent challenges and further research directions of complex hollow nanostructures for energy-related applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Directory of Open Access Journals (Sweden)
Lucrezia eAversa
2015-06-01
Full Text Available Buckminsterfullerene (C60 is a molecule fully formed of carbon that can be used, owing to its electronic and mechanical properties, as clean precursor for the growth of carbon-based materials, ranging from -conjugated systems (graphenes to synthesized species, e.g. carbides such as silicon carbide (SiC. To this goal, C60 cage rupture is the main physical process that triggers material growth. Cage breaking can be obtained either thermally by heating up the substrate to high temperatures (630°C, after C60 physisorption, or kinetically by using Supersonic Molecular Beam Epitaxy (SuMBE techniques. In this work, aiming at demonstrating the growth of SiC thin films by C60 supersonic beams, we present the experimental investigation of C60 impacts on Si(111 7x7 kept at 500°C for translational kinetic energies ranging from 18 to 30 eV. The attained kinetically activated synthesis of SiC submonolayer films is probed by in-situ surface electron spectroscopies (XPS and UPS. Furthermore, in these experimental conditions the C60-Si(111 7×7 collision has been studied by computer simulations based on a tight-binding approximation to Density Functional Theory, DFT. Our theoretical and experimental findings point towards a kinetically driven growth of SiC on Si, where C60 precursor kinetic energy plays a crucial role, while temperature is relevant only after cage rupture to enhance Si and carbon reactivity. In particular, we observe a counterintuitive effect in which for low kinetic energy (below 22 eV, C60 bounces back without breaking more effectively at high temperature due to energy transfer from excited phonons. At higher kinetic energy (22 < K < 30 eV, for which cage rupture occurs, temperature enhances reactivity without playing a major role in the cage break. These results are in good agreement with ab-initio molecular dynamics simulations. SuMBE is thus a technique able to drive materials growth at low temperature regime.
Energy Technology Data Exchange (ETDEWEB)
Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)
1971-07-01
Fission gamma radiation yields as functions of the total fragment kinetic energy were obtained for 235U thermal-neutron induced fission. The fragments were detected with silicon surface-barrier detectors and the gamma radiation with a Nal(Tl) scintillator. In some of the measurements mass selection was used so that the gamma radiation could also be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. Fission-neutron and gamma-ray data of previous experiments were used for comparisons of the yields, and estimates were made of the variation of the prompt gamma-ray energy with the total fragment kinetic energy
QCD Sum-Rule Calculation of the Kinetic Energy and Chromo-Interaction of Heavy Quarks Inside Mesons
Neubert, M
1996-01-01
We present a QCD sum-rule determination of the heavy-quark kinetic energy inside a heavy meson, $-\\lambda_1/2 m_Q$, which is consistent with the field-theory analog of the virial theorem. We obtain $-\\lambda_1\\approx (0.10\\pm 0.05)~\\mbox{GeV}^2$, significantly smaller than a previous sum-rule result, but in good agreement with recent determinations from the analysis of inclusive decays. We also present a new determination of the chromo-magnetic interaction, yielding $\\lambda_2(m_b)=(0.15\\pm 0.03)~\\mbox{GeV}^2$. This implies $m_{B^*}^2-m_B^2=(0.60\\pm 0.12)~\\mbox{GeV}^2$, in good agreement with experiment. As a by-product of our analysis, we derive the QCD sum rules for the three form factors describing the meson matrix element of a velocity-changing current operator containing the gluon field-strength tensor.
Near-Bed Turbulent Kinetic Energy Budget Under a Large-Scale Plunging Breaking Wave Over a Fixed Bar
van der Zanden, Joep; van der A, Dominic A.; Cáceres, Iván.; Hurther, David; McLelland, Stuart J.; Ribberink, Jan S.; O'Donoghue, Tom
2018-02-01
Hydrodynamics under regular plunging breaking waves over a fixed breaker bar were studied in a large-scale wave flume. A previous paper reported on the outer flow hydrodynamics; the present paper focuses on the turbulence dynamics near the bed (up to 0.10 m from the bed). Velocities were measured with high spatial and temporal resolution using a two component laser Doppler anemometer. The results show that even at close distance from the bed (1 mm), the turbulent kinetic energy (TKE) increases by a factor five between the shoaling, and breaking regions because of invasion of wave breaking turbulence. The sign and phase behavior of the time-dependent Reynolds shear stresses at elevations up to approximately 0.02 m from the bed (roughly twice the elevation of the boundary layer overshoot) are mainly controlled by local bed-shear-generated turbulence, but at higher elevations Reynolds stresses are controlled by wave breaking turbulence. The measurements are subsequently analyzed to investigate the TKE budget at wave-averaged and intrawave time scales. Horizontal and vertical turbulence advection, production, and dissipation are the major terms. A two-dimensional wave-averaged circulation drives advection of wave breaking turbulence through the near-bed layer, resulting in a net downward influx in the bar trough region, followed by seaward advection along the bar's shoreward slope, and an upward outflux above the bar crest. The strongly nonuniform flow across the bar combined with the presence of anisotropic turbulence enhances turbulent production rates near the bed.
The average kinetic energy of the heavy quark in Λb in the Bethe-Salpeter equation approach
International Nuclear Information System (INIS)
Guo, X.-H.; Wu, H.-K.
2007-01-01
In the previous paper, based on the SU(2) f xSU(2) s heavy quark symmetries of the QCD Lagrangian in the heavy quark limit, the Bethe-Salpeter equation for the heavy baryon Λ b was established with the picture that Λ b is composed of a heavy quark and a scalar light diquark. In the present work, we apply this model to calculate μ π 2 for Λ b , the average kinetic energy of the heavy quark inside Λ b . This quantity is particularly interesting since it can be measured in experiments and since it contributes to the inclusive semileptonic decays of Λ b when contributions from higher order terms in 1/M b expansions are taken into account and consequently influences the determination of the Cabibbo-Kobayashi-Maskawa matrix elements V ub and V cb . We find that μ π 2 for Λ b is 0.25GeV 2 ∼0.95GeV 2 , depending on the parameters in the model including the light diquark mass and the interaction strength between the heavy quark and the light diquark in the kernel of the BS equation. We also find that this result is consistent with the value of μ π 2 for Λ b which is derived from the experimental value of μ π 2 for the B meson with the aid of the heavy quark effective theory
Directory of Open Access Journals (Sweden)
Wen-Tao Su
2014-07-01
Full Text Available This paper is to make a better understanding of the flow instabilities and turbulent kinetic energy (TKE features in a large-scale Francis hydroturbine model. The flow instability with aspect of pressure oscillation and pressure-velocity correlation was investigated using large eddy simulation (LES method along with two-phase cavitation model. The numerical simulation procedures were validated by the existing experimental result, and further the TKE evolution was analyzed in a curvilinear coordinates. By monitoring the fluctuating pressure and velocities in the vanes’ wake region, the local pressure and velocity variations were proven to have a phase difference approaching π/2, with a reasonable cross-correlation coefficient. Also the simultaneous evolution of pressure fluctuations at the opposite locations possessed a clear phase difference of π, indicating the stresses variations on the runner induced by pressure oscillation were in an odd number of nodal diameter. Considering the TKE generation, the streamwise velocity component us′2 contributed the most to the TKE, and thus the normal stress production term and shear stress production term imparted more instability to the flow than other production terms.