Quantum fields and dissipation
International Nuclear Information System (INIS)
Henning, P.
1996-06-01
The description of thermal or non-equilibrium systems necessitates a quantum field theory which differs from the usual approach in two aspects: 1. The Hilbert space is doubled; 2. Stable quasi-particles do not exist in interacting systems. A mini-review of these two aspects is given from a practical viewpoint including two applications. For thermal states it is shown how infrared divergences occuring in perturbative quasi-particle theories are avoided, whereas for non-equilibrium states a memory effect is shown to arise in the thermalization. (orig.)
Dissipative charged fluid in a magnetic field
Energy Technology Data Exchange (ETDEWEB)
Abbasi, Navid; Davody, Ali, E-mail: davody.phy@gmail.com
2016-05-10
We study the collective excitations in a dissipative charged fluid at zero chemical potential when an external magnetic field is present. While in the absence of magnetic field, four collective excitations appear in the fluid, we find five hydrodynamic modes here. This implies that the magnetic field splits the degeneracy between the transverse shear modes. Using linear response theory, we then compute the retarded response functions. In particular, it turns out that the correlation between charge and the energy fluctuations will no longer vanish, even at zero chemical potential. By use of the response functions, we also derive the relevant Kubo formulas for the transport coefficients.
Dissipation element analysis of turbulent scalar fields
International Nuclear Information System (INIS)
Wang Lipo; Peters, Norbert
2008-01-01
Dissipation element analysis is a new approach for studying turbulent scalar fields. Gradient trajectories starting from each material point in a scalar field Φ'(x-vector,t) in ascending directions will inevitably reach a maximal and a minimal point. The ensemble of material points sharing the same pair ending points is named a dissipation element. Dissipation elements can be parameterized by the length scale l and the scalar difference Δφ ', which are defined as the straight line connecting the two extremal points and the scalar difference at these points, respectively. The decomposition of a turbulent field into dissipation elements is space-filling. This allows us to reconstruct certain statistical quantities of fine scale turbulence which cannot be obtained otherwise. The marginal probability density function (PDF) of the length scale distribution based on a Poisson random cutting-reconnection process shows satisfactory agreement with the direct numerical simulation (DNS) results. In order to obtain the further information that is needed for the modeling of scalar mixing in turbulence, such as the marginal PDF of the length of elements and all conditional moments as well as their scaling exponents, there is a need to model the joint PDF of l and Δφ ' as well. A compensation-defect model is put forward in this work to show the dependence of Δφ ' on l. The agreement between the model prediction and DNS results is satisfactory, which may provide another explanation of the Kolmogorov scaling and help to improve turbulent mixing models. Furthermore, intermittency and cliff structure can also be related to and explained from the joint PDF.
Quantified Energy Dissipation Rates in the Terrestrial Bow Shock. 2; Waves and Dissipation
Wilson, L. B., III; Sibeck, D. G.; Breneman, A. W.; Le Contel, O.; Cully, C.; Turner, D. L.; Angelopoulos, V.; Malaspina, D. M.
2014-01-01
We present the first quantified measure of the energy dissipation rates, due to wave-particle interactions, in the transition region of the Earth's collision-less bow shock using data from the Time History of Events and Macro-Scale Interactions during Sub-Storms spacecraft. Our results show that wave-particle interactions can regulate the global structure and dominate the energy dissipation of collision-less shocks. In every bow shock crossing examined, we observed both low-frequency (less than 10 hertz) and high-frequency (approximately or greater than10 hertz) electromagnetic waves throughout the entire transition region and into the magnetosheath. The low-frequency waves were consistent with magnetosonic-whistler waves. The high-frequency waves were combinations of ion-acoustic waves, electron cyclotron drift instability driven waves, electrostatic solitary waves, and whistler mode waves. The high-frequency waves had the following: (1) peak amplitudes exceeding delta B approximately equal to 10 nanoteslas and delta E approximately equal to 300 millivolts per meter, though more typical values were delta B approximately equal to 0.1-1.0 nanoteslas and delta E approximately equal to 10-50 millivolts per meter (2) Poynting fluxes in excess of 2000 microWm(sup -2) (micro-waves per square meter) (typical values were approximately 1-10 microWm(sup -2) (micro-waves per square meter); (3) resistivities greater than 9000 omega meters; and (4) associated energy dissipation rates greater than 10 microWm(sup -3) (micro-waves per cubic meter). The dissipation rates due to wave-particle interactions exceeded rates necessary to explain the increase in entropy across the shock ramps for approximately 90 percent of the wave burst durations. For approximately 22 percent of these times, the wave-particle interactions needed to only be less than or equal to 0.1 percent efficient to balance the nonlinear wave steepening that produced the shock waves. These results show that wave
Fluctuation and dissipation in nonequilibrium quantum field theory
International Nuclear Information System (INIS)
Ramos, Rudnei O.
1994-01-01
The nonequilibrium dynamics of a scalar field is studied using perturbation theory and a real time finite temperature formulation. The evolution equation for the scalar field is explicitly obtained, and terms responsible for noise (fluctuations) and dissipation are identified and studied in the high temperature limit. (author)
Dissipation and fluctuation of quantum fields in expanding universes
International Nuclear Information System (INIS)
Morikawa, M.
1990-01-01
A stochastic dynamics of a long-wavelength part of a scalar field in an expanding universe is derived by using the influence functional method. Dissipation as well as fluctuation are derived for general parameters: a mass, a coupling to the scalar curvature, and a cutoff scale parameter. A dissipation-fluctuation relation is found with a temperature which is proportional to the Hawking temperature, but system dependent. The method is further applied to an expanding universe with a power law and yields the dispersion which agrees with that obtained by the regularization method. The back reaction to the background de Sitter space itself is also obtained
A field theory description of constrained energy-dissipation processes
International Nuclear Information System (INIS)
Mandzhavidze, I.D.; Sisakyan, A.N.
2002-01-01
A field theory description of dissipation processes constrained by a high-symmetry group is given. The formalism is presented in the example of the multiple-hadron production processes, where the transition to the thermodynamic equilibrium results from the kinetic energy of colliding particles dissipating into hadron masses. The dynamics of these processes is restricted because the constraints responsible for the colour charge confinement must be taken into account. We develop a more general S-matrix formulation of the thermodynamics of nonequilibrium dissipative processes and find a necessary and sufficient condition for the validity of this description; this condition is similar to the correlation relaxation condition, which, according to Bogolyubov, must apply as the system approaches equilibrium. This situation must physically occur in processes with an extremely high multiplicity, at least if the hadron mass is nonzero. We also describe a new strong-coupling perturbation scheme, which is useful for taking symmetry restrictions on the dynamics of dissipation processes into account. We review the literature devoted to this problem
Parallel magnetic field suppresses dissipation in superconducting nanostrips
Energy Technology Data Exchange (ETDEWEB)
Wang, Yong-Lei; Glatz, Andreas; Kimmel, Gregory J.; Aranson, Igor S.; Thoutam, Laxman R.; Xiao, Zhi-Li; Berdiyorov, Golibjon R.; Peeters, François M.; Crabtree, George W.; Kwok, Wai-Kwong
2017-11-13
The motion of Abrikosov vortices in type-II superconductors results in a finite resistance in the presence of an applied electric current. Elimination or reduction of the resistance via immobilization of vortices is the "holy grail" of superconductivity research. Common wisdom dictates that an increase in the magnetic field escalates the loss of energy since the number of vortices increases. Here we show that this is no longer true if the magnetic field and the current are applied parallel to each other. Our experimental studies on the resistive behavior of a superconducting Mo0.79Ge0.21 nanostrip reveal the emergence of a dissipative state with increasing magnetic field, followed by a pronounced resistance drop, signifying a reentrance to the superconducting state. Large-scale simulations of the 3D time-dependent Ginzburg-Landau model indicate that the intermediate resistive state is due to an unwinding of twisted vortices. When the magnetic field increases, this instability is suppressed due to a better accommodation of the vortex lattice to the pinning configuration. Our findings show that magnetic field and geometrical confinement can suppress the dissipation induced by vortex motion and thus radically improve the performance of superconducting materials.
Parallel magnetic field suppresses dissipation in superconducting nanostrips.
Wang, Yong-Lei; Glatz, Andreas; Kimmel, Gregory J; Aranson, Igor S; Thoutam, Laxman R; Xiao, Zhi-Li; Berdiyorov, Golibjon R; Peeters, François M; Crabtree, George W; Kwok, Wai-Kwong
2017-11-28
The motion of Abrikosov vortices in type-II superconductors results in a finite resistance in the presence of an applied electric current. Elimination or reduction of the resistance via immobilization of vortices is the "holy grail" of superconductivity research. Common wisdom dictates that an increase in the magnetic field escalates the loss of energy since the number of vortices increases. Here we show that this is no longer true if the magnetic field and the current are applied parallel to each other. Our experimental studies on the resistive behavior of a superconducting Mo 0.79 Ge 0.21 nanostrip reveal the emergence of a dissipative state with increasing magnetic field, followed by a pronounced resistance drop, signifying a reentrance to the superconducting state. Large-scale simulations of the 3D time-dependent Ginzburg-Landau model indicate that the intermediate resistive state is due to an unwinding of twisted vortices. When the magnetic field increases, this instability is suppressed due to a better accommodation of the vortex lattice to the pinning configuration. Our findings show that magnetic field and geometrical confinement can suppress the dissipation induced by vortex motion and thus radically improve the performance of superconducting materials.
Dissipative Effects in the Effective Field Theory of Inflation
Energy Technology Data Exchange (ETDEWEB)
Lopez Nacir, Diana; /Buenos Aires, CONICET /Buenos Aires U.; Porto, Rafael A.; /Princeton, Inst. Advanced Study /ISCAP, New York /Columbia U.; Senatore, Leonardo; /Stanford U., ITP /SLAC /KIPAC, Menlo Park; Zaldarriaga, Matias; /Princeton, Inst. Advanced Study
2012-09-14
We generalize the effective field theory of single clock inflation to include dissipative effects. Working in unitary gauge we couple a set of composite operators, {Omicron}{sub {mu}{nu}}..., in the effective action which is constrained solely by invariance under time-dependent spatial diffeomorphisms. We restrict ourselves to situations where the degrees of freedom responsible for dissipation do not contribute to the density perturbations at late time. The dynamics of the perturbations is then modified by the appearance of 'friction' and noise terms, and assuming certain locality properties for the Green's functions of these composite operators, we show that there is a regime characterized by a large friction term {gamma} >> H in which the {zeta}-correlators are dominated by the noise and the power spectrum can be significantly enhanced. We also compute the three point function <{zeta}{zeta}{zeta}> for a wide class of models and discuss under which circumstances large friction leads to an increased level of non-Gaussianities. In particular, under our assumptions, we show that strong dissipation together with the required non-linear realization of the symmetries implies |f{sub NL}| {approx} {gamma}/c{sub s}{sup 2} H >> 1. As a paradigmatic example we work out a variation of the 'trapped inflation' scenario with local response functions and perform the matching with our effective theory. A detection of the generic type of signatures that result from incorporating dissipative effects during inflation, as we describe here, would teach us about the dynamics of the early universe and also extend the parameter space of inflationary models.
Relaxational dissipation of magnetic field energy in a rarefied plasma
International Nuclear Information System (INIS)
Vekshtejn, G.E.
1987-01-01
A mechanism of solar corona plasma heating connected with relaxation of a magnetic configuration in the corona to the state of the magnetic energy minimum at restrictions imposed by high conductivity of a medium is considered. Photospheric plasma pulsations leading to generation of longitudinal currents in the corona are in this case energy sources. The excess magnetic energy of these currents is dissipated as a result of reclosing of force lines of the magnetic field in narrow current layers. Plasmaturbulence related to the process of magnetic reclosing is phenomenologically described in this case by introducing certain characteristic time of relaxation. Such an approach permits to relate the plasma heating energy with parameters of photospheric motions in the framework of a simple model of the magnetic field
Dissipation and residue of bifenthrin in wheat under field conditions.
You, Xiangwei; Jiang, Naiwen; Liu, Fengmao; Liu, Congyun; Wang, Suli
2013-02-01
Field trials were carried out to investigate the dissipation and residue levels of bifenthrin in wheat. After extraction with acetonitrile, the samples were cleaned up by dispersive solid-phase extraction and detected by gas chromatography-mass spectrometry. The half-lives of bifenthrin in wheat seedlings ranged from 2.4 to 10.5 days. At harvest time, the terminal residues of bifenthrin were below the maximum residue limit (0.5 mg/kg) set by Codex Alimentarius Committee or European Union in wheat grain, which suggested that the use of this pesticide was safe for humans. However, the relatively high residue levels of bifenthrin in wheat straw should be paid attention to.
Dissipation of Pendimethalin in Soybean Crop Under Field Conditions.
Tandon, Shishir
2016-05-01
Persistence of pendimethalin was studied in soil, soybean pods, straw and water under field conditions. Pendimethalin was applied at 1 and 2 kg a.i. ha(-1). Residues in soil were detected up to 60 and 90 days at the recommended and double dose, respectively. Dissipation followed first order kinetics and was accounted for by a biphasic pattern. The half-life for the initial phase and later phase was 12.73 and 26.60 days, respectively, for recommended and 7.25 and 37.91 days, respectively, for double dose. The limit of quantification was 0.005 µg g(-1) of sample. Percent recovery from soil, oil, defatted cake, straw and water samples fortified with 0.01-1.0 mg kg(-1) varied from 84.5 %-89.6 %, 84.6 %-88.7 %, 79.4 %-86.0 %, 78.2 %-85.6 % and 90.2 %-93.0 %, respectively. At harvest, pendimethalin residue in soybean pods, straw, and soil were below detectable limits. No residues of pendimethalin were detected in ground water. Current application of pendimethalin in the environment is not expected to cause adverse health effects form the consumption of soybeans.
Dissipation and Residue Level of Thifluzamide in Rice Field Ecosystem
Directory of Open Access Journals (Sweden)
Weitao Chen
2015-01-01
Full Text Available An efficient modified QuEChERS method combined with high performance liquid chromatography-tandem mass spectrometry detection (HPLC-MS/MS was established and evaluated for the residue analysis of thifluzamide in rice grain, husk, straw, seedling, paddy water, and soil. Thifluzamide residues were extracted with acetonitrile, cleaned up with primary secondary amine (PSA, and then determined by HPLC-MS/MS. The fortified recoveries were 76%–106% with RSDs of 3%–13%. The results of the supervised field trials at two experiment sites showed that thifluzamide dissipated rapidly in paddy fields, and the half-lives in paddy water, soil, and rice seedling were 0.3–0.6 d, 1.8–3.6 d, and 4.3–13.9 d, respectively. At harvest time, when the preharvest interval (PHI was set as 21 d, the final residues of thifluzamide in rice grains were below the maximum residue limit (MRL of 0.5 mg/kg set by Japan, whereas the final residues in rice husk and straw were still high (the highest value reached 1.36 mg/kg in rice husk and 0.83 mg/kg in rice straw. The results indicated that the highest residue in rice grain was 0.23 mg/kg when PHI was 21 d, and only 6.9–11.0% of acute risk quotient of thifluzamide was occupied by the dietary daily intake in Chinese population consuming rice.
Entanglement generation through local field and quantum dissipation
International Nuclear Information System (INIS)
Stockburger, Jürgen T; Schmidt, Rebecca; Ankerhold, Joachim
2015-01-01
Entanglement in a Gaussian two-mode system can be generated by local driving if additional non-local features are introduced to the dynamics. We demonstrate that weak to moderate ohmic friction arising from a dissipative environment can enable entanglement generation in a driven system. This synergy of driving and dissipation is highly sensitive to the pulse shape; several simple pulse shapes fail to produce this effect at all or deposit large amounts of energy in the system as a side effect. Complex pulse shapes, determined by optimal control techniques, however, are effective without detrimental side effects. (paper)
Smart Rotorcraft Field Assistants for Terrestrial and Planetary Science
Young, Larry A.; Aiken, Edwin W.; Briggs, Geoffrey A.
2004-01-01
Field science in extreme terrestrial environments is often difficult and sometimes dangerous. Field seasons are also often short in duration. Robotic field assistants, particularly small highly mobile rotary-wing platforms, have the potential to significantly augment a field season's scientific return on investment for geology and astrobiology researchers by providing an entirely new suite of sophisticated field tools. Robotic rotorcraft and other vertical lift planetary aerial vehicle also hold promise for supporting planetary science missions.
Similon, Philippe L.; Sudan, R. N.
1989-01-01
The importance of field line geometry for shear Alfven wave dissipation in coronal arches is demonstrated. An eikonal formulation makes it possible to account for the complicated magnetic geometry typical in coronal loops. An interpretation of Alfven wave resonance is given in terms of gradient steepening, and dissipation efficiencies are studied for two configurations: the well-known slab model with a straight magnetic field, and a new model with stochastic field lines. It is shown that a large fraction of the Alfven wave energy flux can be effectively dissipated in the corona.
Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Black, Carrie; Kuznetsova, Masha
2011-01-01
It was recently proposed that the electron-frame dissipation measure, the energy transfer from the electromagnetic field to plasmas in the electron s rest frame, identifies the dissipation region of collisionless magnetic reconnection [Zenitani et al., Phys. Rev. Lett. 106, 195003 (2011)]. The measure is further applied to the electron-scale structures of antiparallel reconnection, by using two-dimensional particle-in-cell simulations. The size of the central dissipation region is controlled by the electron-ion mass ratio, suggesting that electron physics is essential. A narrow electron jet extends along the outflow direction until it reaches an electron shock. The jet region appears to be anti-dissipative. At the shock, electron heating is relevant to a magnetic cavity signature. The results are summarized to a unified picture of the single dissipation region in a Hall magnetic geometry.
International Nuclear Information System (INIS)
Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Black, Carrie; Kuznetsova, Masha
2011-01-01
It was recently proposed that the electron-frame dissipation measure, the energy transfer from the electromagnetic field to plasmas in the electron's rest frame, identifies the dissipation region of collisionless magnetic reconnection [Zenitani et al., Phys. Rev. Lett. 106, 195003 (2011)]. The measure is further applied to the electron-scale structures of antiparallel reconnection, by using two-dimensional particle-in-cell simulations. The size of the central dissipation region is controlled by the electron-ion mass ratio, suggesting that electron physics is essential. A narrow electron jet extends along the outflow direction until it reaches an electron shock. The jet region appears to be anti-dissipative. At the shock, electron heating is relevant to a magnetic cavity signature. The results are summarized to a unified picture of the single dissipation region in a Hall magnetic geometry.
Energy Technology Data Exchange (ETDEWEB)
Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Black, Carrie; Kuznetsova, Masha [NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)
2011-12-15
It was recently proposed that the electron-frame dissipation measure, the energy transfer from the electromagnetic field to plasmas in the electron's rest frame, identifies the dissipation region of collisionless magnetic reconnection [Zenitani et al., Phys. Rev. Lett. 106, 195003 (2011)]. The measure is further applied to the electron-scale structures of antiparallel reconnection, by using two-dimensional particle-in-cell simulations. The size of the central dissipation region is controlled by the electron-ion mass ratio, suggesting that electron physics is essential. A narrow electron jet extends along the outflow direction until it reaches an electron shock. The jet region appears to be anti-dissipative. At the shock, electron heating is relevant to a magnetic cavity signature. The results are summarized to a unified picture of the single dissipation region in a Hall magnetic geometry.
[The design of heat dissipation of the field low temperature box for storage and transportation].
Wei, Jiancang; Suin, Jianjun; Wu, Jian
2013-02-01
Because of the compact structure of the field low temperature box for storage and transportation, which is due to the same small space where the compressor, the condenser, the control circuit, the battery and the power supply device are all placed in, the design for heat dissipation and ventilation is of critical importance for the stability and reliability of the box. Several design schemes of the heat dissipation design of the box were simulated using the FLOEFD hot fluid analysis software in this study. Different distributions of the temperature field in every design scheme were constructed intimately in the present study. It is well concluded that according to the result of the simulation analysis, the optimal heat dissipation design is decent for the field low temperature box for storage and transportation, and the box can operate smoothly for a long time using the results of the design.
Measurement of the terrestrial magnetic field and its anomalies
International Nuclear Information System (INIS)
Duret, D.
1994-01-01
After a presentation of the terrestrial magnetic field and its various anomalies, the different types of magnetometers commonly used are reviewed with their characteristics and performances: scalar magnetometers (free precession and continuous polarization proton magnetometers, dynamic polarization proton magnetometers, optical pumping magnetometers, electronic resonance scalar magnetometers (without pumping)); vectorial magnetometers (flux gate magnetometers, induction magnetometers, suspended magnet magnetometers, superconducting magnetometers, integrated magnetometers, resonance directional magnetometers). The magnetometry market and applications are discussed. 20 figs., 9 tabs., 72 refs
Effects on the CMB from magnetic field dissipation before recombination
Kunze, Kerstin E.
2017-09-01
Magnetic fields present before decoupling are damped due to radiative viscosity. This energy injection affects the thermal and ionization history of the cosmic plasma. The implications for the CMB anisotropies and polarization are investigated for different parameter choices of a nonhelical stochastic magnetic field. Assuming a Gaussian smoothing scale determined by the magnetic damping wave number at recombination, it is found that magnetic fields with present-day strength less than 0.1 nG and negative magnetic spectral indices have a sizable effect on the CMB temperature anisotropies and polarization.
TenBarge, J. M.; Shay, M. A.; Sharma, P.; Juno, J.; Haggerty, C. C.; Drake, J. F.; Bhattacharjee, A.; Hakim, A.
2017-12-01
Turbulence and magnetic reconnection are the primary mechanisms responsible for the conversion of stored magnetic energy into particle energy in many space and astrophysical plasmas. The magnetospheric multiscale mission (MMS) has given us unprecedented access to high cadence particle and field data of turbulence and magnetic reconnection at earth's magnetopause. The observations include large guide field reconnection events generated within the turbulent magnetopause. Motivated by these observations, we present a study of large guide reconnection using the fully kinetic Eulerian Vlasov-Maxwell component of the Gkeyll simulation framework, and we also employ and compare with gyrokinetics to explore the asymptotically large guide field limit. In addition to studying the configuration space dynamics, we leverage the recently developed field-particle correlations to diagnose the dominant sources of dissipation and compare the results of the field-particle correlation to other energy dissipation measures.
International Nuclear Information System (INIS)
Kang Guo-Dong; Fang Mao-Fa; Ouyang Xi-Cheng; Deng Xiao-Juan
2010-01-01
Considering two identical two-level atoms interacting with a single-model dissipative coherent cavity field without rotating wave approximation, we explore the entanglement dynamics of the two atoms prepared in different states using concurrence. Interestingly, our results show that the entanglement between the two atoms that initially disentangled will come up to a large constant rapidly, and then keeps steady in the following time or always has its maximum when prepared in some special Bell states. The model considered in this study is a good candidate for quantum information processing especially for quantum computation as steady high-degree atomic entanglement resource obtained in dissipative cavity
Mean field instabilities in dissipative heavy ion collisions
International Nuclear Information System (INIS)
Colonna, M.; Guarnera, A.; Istituto Nazionale di Fisica Nucleare, Bologna; Catania Univ.; Di Torro, M.; Catania Univ.
1995-01-01
We discuss new reaction mechanisms that may occur in semi-peripheral heavy ion collisions at intermediate energies. In particular we focus on the dynamics of the overlapping zone, showing the development of neck instabilities, coupled with the possibility of an increasing amount amount of dynamical fluctuations. In a very selected beam energy range between 40 and 70 MeV/u we observe an important interplay between stochastic nucleon exchange and the random nature of nucleon-nucleon collisions. Expected consequences are intermediate mass fragment emissions from the neck region and large variances in the projectile-like and target-like observables. The crucial importance of a time matching between the growth of mean field instabilities and the separation of the interacting system is stressed. Some hints towards the observation of relatively large instability effects in deep inelastic collisions at lower energy are finally suggested. (authors). 29 refs., 5 figs., 2 tabs
Rate-independent dissipation in phase-field modelling of displacive transformations
Tůma, K.; Stupkiewicz, S.; Petryk, H.
2018-05-01
In this paper, rate-independent dissipation is introduced into the phase-field framework for modelling of displacive transformations, such as martensitic phase transformation and twinning. The finite-strain phase-field model developed recently by the present authors is here extended beyond the limitations of purely viscous dissipation. The variational formulation, in which the evolution problem is formulated as a constrained minimization problem for a global rate-potential, is enhanced by including a mixed-type dissipation potential that combines viscous and rate-independent contributions. Effective computational treatment of the resulting incremental problem of non-smooth optimization is developed by employing the augmented Lagrangian method. It is demonstrated that a single Lagrange multiplier field suffices to handle the dissipation potential vertex and simultaneously to enforce physical constraints on the order parameter. In this way, the initially non-smooth problem of evolution is converted into a smooth stationarity problem. The model is implemented in a finite-element code and applied to solve two- and three-dimensional boundary value problems representative for shape memory alloys.
Dissipation of the Herbicide Benzobicyclon Hydrolysate in a Model California Rice Field Soil.
Williams, Katryn L; Gladfelder, Joshua J; Quigley, Lindsay L; Ball, David B; Tjeerdema, Ronald S
2017-10-25
The herbicide benzobicyclon (BZB; 3-(2-chloro-4-(methylsulfonyl)benzoyl)-2-phenylthiobicyclo[3.2.1]oct-2-en-4-one) has recently been approved for use on California rice fields by the United States Environmental Protection Agency (U.S. EPA). Hydrolysis of BZB rapidly forms the active compound, benzobicyclon hydrolysate (BH), whose fate is currently not well understood. A model California rice soil was used to determine BH soil dissipation. The pK a and aqueous solubility were also determined, as experimental values are not currently available. Sorption data indicate BH does not bind tightly, or irreversibly, with this soil. Flooding resulted in decreased BH loss, indicating anaerobic microbes are less likely to transform BH compared to aerobic microorganisms. Temperature increased dissipation, while autoclaving decreased BH loss. Overall, dissipation was slow regardless of treatment. Further investigation is needed to elucidate the exact routes of loss in soil, though BH is expected to dissipate slowly in flooded rice field soil.
Three-dimensional modeling of electron quasiviscous dissipation in guide-field magnetic reconnection
International Nuclear Information System (INIS)
Hesse, Michael; Kuznetsova, Masha; Schindler, Karl; Birn, Joachim
2005-01-01
A numerical study of guide-field magnetic reconnection in a three-dimensional model is presented. Starting from an initial, perturbed, force-free current sheet, it is shown that reconnection develops to an almost translationally invariant state, where magnetic perturbations are aligned primarily along the main current flow direction. An analysis of guide-field and electron flow signatures indicates behavior that is very similar to earlier, albeit not three-dimensional, simulations. Furthermore, a detailed investigation of electron pressure nongyrotropies in the central diffusion region confirms the major role the associated dissipation process plays in establishing the reconnection electric field
Field dissipation of oxyfluorfen in onion and its dynamics in soil under Indian tropical conditions.
Janaki, P; Sathya Priya, R; Chinnusamy, C
2013-01-01
Oxyfluorfen, a diphenyl-ether herbicide is being used to control annual and perennial broad-leaved weeds and sedges in a variety of field crops including onion. The present study was aimed to investigate the dynamics and field persistence of oxyfluorfen in onion plant, bulb and soil under Indian tropical conditions. Application of four rates of oxyfluorfen viz., 200, 250, 300 and 400 g AI ha(-1) as pre-emergence gave good weed control in field experiment with onion. The oxyfluorfen residue dissipated faster in plant than in soil respectively, with a mean half-life of 6.1 and 11.2 days. Dissipation followed first-order kinetics. In laboratory column leaching experiments, 17 percent of the applied oxyfluorfen was recovered from the soil and indicates its solubility in water and mobility in sandy clay loam soil was low. A sorption study revealed that the adsorption of oxyfluorfen to the soil was highly influenced by the soil organic carbon with the Koc value of 5450. The study concludes that the dissipation of oxyfluorfen in soil and onion was dependent on the physico-chemical properties of the soil and environmental conditions.
National Research Council Canada - National Science Library
Vischer, D. L; Hager, Willi H; Hager, W. H
1995-01-01
.... the book comprises chapters in farious fields such as hydraulic jump, stilling basins, ski jumps and plunge pools but introduces also a general account on various methods of dissipation, as well...
Spherical Magnetic Vortex in an External Potential Field: A Dissipative Contraction
Solov'ev, A. A.
2013-09-01
We consider the dissipative evolution of a spherical magnetic vortex with a force-free internal structure, located in a resistive medium and held in equilibrium by the potential external field. The magnetic field inside the sphere is force-free (the model of Chandrasekhar in Proc. Natl. Acad. Sci. 42, 1, 1956). Topologically, it is a set of magnetic toroids enclosed in spherical layers. A new exact MHD solution has been derived, describing a slow, uniform, radial compression of a magnetic spheroid under the pressure of an ambient field, when the plasma density and pressure are growing inside it. There is no dissipation in the potential field outside the sphere, but inside the sphere, where the current density can be high enough, the magnetic energy is continuously converted into heat. Joule dissipation lowers the magnetic pressure inside the sphere, which balances the pressure of the ambient field. This results in radial contraction of the magnetic sphere with a speed defined by the conductivity of the plasma and the characteristic spatial scale of the magnetic field inside the sphere. Formally, the sphere shrinks to zero within a finite time interval (magnetic collapse). The time of compression can be relatively small, within a day, even for a sphere with a radius of about 1 Mm, if the magnetic helicity trapped initially in the sphere (which is proportional to the number of magnetic toroids in the sphere) is quite large. The magnetic system is open along its axis of symmetry. On this axis, the magnetic and electric fields are strictly radial and sign-variable along the radius, so the plasma will be ejected along the axis of magnetic sphere outwards in both directions (as jets) at a rate much higher than the diffusive one, and the charged particles will be accelerated unevenly, in spurts, creating quasi-regular X-ray spikes. The applications of the solution to solar flares are discussed.
Dynamical Properties of Two Coupled Dissipative QED Cavities Driven by Coherent Fields
International Nuclear Information System (INIS)
Hou Bangpin; Sun Weili; Wang Shunjin; Wang Gang
2007-01-01
When two identical QED cavities driven by the coherent fields are located in a uniform environment, in addition to dissipation, there appears an indirect coupling between the two cavities induced by the background fields. We investigate the effects of the coherent fields, the dissipation as well as the incoherent coupling on the following dynamical properties of the system: photon transfer, reversible decoherence, and quantum state transfer, etc. We find that the photons in the cavities do not leak completely into the environment due to the collective coupling between the cavities and the environment, and the photons are transferred irreversibly from the cavity with more photons to the cavity with less ones due to the incoherent coupling so that they are equally distributed among the two cavities. The coherent field pumping on the two cavities increases the mean photons, complements the revived magnitude of the reversible decoherence, but hinders the quantum state transfer between the two cavities. The above phenomena may find applications in quantum communication and other basic fields.
Directory of Open Access Journals (Sweden)
Xiao-Yin Pan
2018-03-01
Full Text Available Dissipative effects arise in an electronic system when it interacts with a time-dependent environment. Here, the Schrödinger theory of electrons in an electromagnetic field including dissipative effects is described from a new perspective. Dissipation is accounted for via the effective Hamiltonian approach in which the electron mass is time-dependent. The perspective is that of the individual electron: the corresponding equation of motion for the electron or time-dependent differential virial theorem—the ‘Quantal Newtonian’ second law—is derived. According to the law, each electron experiences an external field comprised of a binding electric field, the Lorentz field, and the electromagnetic field. In addition, there is an internal field whose components are representative of electron correlations due to the Pauli exclusion principle and Coulomb repulsion, kinetic effects, and density. There is also an internal contribution due to the magnetic field. The response of the electron is governed by the current density field in which a damping coefficient appears. The law leads to further insights into Schrödinger theory, and in particular the intrinsic self-consistent nature of the Schrödinger equation. It is proved that in the presence of dissipative effects, the basic variables (gauge-invariant properties, knowledge of which determines the Hamiltonian are the density and physical current density. Finally, a local effective potential theory of dissipative systems—quantal density functional theory (QDFT—is developed. This constitutes the mapping from the interacting dissipative electronic system to one of noninteracting fermions possessing the same dissipation and basic variables. Attributes of QDFT are the separation of the electron correlations due to the Pauli exclusion principle and Coulomb repulsion, and the determination of the correlation contributions to the kinetic energy. Hence, Schrödinger theory in conjunction with QDFT
Directory of Open Access Journals (Sweden)
Uwe C. Täuber
2014-04-01
Full Text Available The universal critical behavior of the driven-dissipative nonequilibrium Bose-Einstein condensation transition is investigated employing the field-theoretical renormalization group method. Such criticality may be realized in broad ranges of driven open systems on the interface of quantum optics and many-body physics, from exciton-polariton condensates to cold atomic gases. The starting point is a noisy and dissipative Gross-Pitaevski equation corresponding to a complex-valued Landau-Ginzburg functional, which captures the near critical nonequilibrium dynamics, and generalizes model A for classical relaxational dynamics with nonconserved order parameter. We confirm and further develop the physical picture previously established by means of a functional renormalization group study of this system. Complementing this earlier numerical analysis, we analytically compute the static and dynamical critical exponents at the condensation transition to lowest nontrivial order in the dimensional ε expansion about the upper critical dimension d_{c}=4 and establish the emergence of a novel universal scaling exponent associated with the nonequilibrium drive. We also discuss the corresponding situation for a conserved order parameter field, i.e., (subdiffusive model B with complex coefficients.
Cluster Mean-Field Approach to the Steady-State Phase Diagram of Dissipative Spin Systems
Directory of Open Access Journals (Sweden)
Jiasen Jin
2016-07-01
Full Text Available We show that short-range correlations have a dramatic impact on the steady-state phase diagram of quantum driven-dissipative systems. This effect, never observed in equilibrium, follows from the fact that ordering in the steady state is of dynamical origin, and is established only at very long times, whereas in thermodynamic equilibrium it arises from the properties of the (free energy. To this end, by combining the cluster methods extensively used in equilibrium phase transitions to quantum trajectories and tensor-network techniques, we extend them to nonequilibrium phase transitions in dissipative many-body systems. We analyze in detail a model of spin-1/2 on a lattice interacting through an XYZ Hamiltonian, each of them coupled to an independent environment that induces incoherent spin flips. In the steady-state phase diagram derived from our cluster approach, the location of the phase boundaries and even its topology radically change, introducing reentrance of the paramagnetic phase as compared to the single-site mean field where correlations are neglected. Furthermore, a stability analysis of the cluster mean field indicates a susceptibility towards a possible incommensurate ordering, not present if short-range correlations are ignored.
Residues and dissipation of kresoxim methyl in apple under field condition.
Malhat, Farag; Kamel, Essam; Saber, Ayman; Hassan, Ehab; Youssef, Ahmed; Almaz, Monir; Hassan, Ayman; Fayz, Abd El-Salam
2013-09-01
The dissipation and residual levels of kresoxim methyl in apple under field condition were determined by using HPLC-DAD with QuEChERS method. At fortification levels of 0.05, 0.1, 0.5 and 1.0 mg kg(-1) in apple, it was shown that recoveries were ranged from 91.1% to 96.9% with coefficient variation of the method (CV%) for repeatability ranged from 1.27% to 4.77%. The limit of quantification (LOQ) of the method was 0.05 mg kg(-1). The dissipation rates of kresoxim methyl were described by using first-order kinetics and its half-life, as they are ranged from 4.58 to 4.77 days in apple. The terminal residues of kresoxim methyl were below the FAO/WHO maximum residue limit (MRL, 0.2 mg kg(-1)) in apple when measured 14 days after the final application, which suggested that the use of this fungicide was safe for humans. This study would help in providing the basic information for developing regulation to guard a safe use of kresoxim methyl in apple orchard and to prevent health problem from consumers. Copyright © 2013 Elsevier Ltd. All rights reserved.
Dissipation of pyraclostrobin and its metabolite BF-500-3 in maize under field conditions.
You, Xiangwei; Liu, Congyun; Liu, Fengmao; Liu, Yanping; Dong, Jiannan
2012-06-01
The dissipation and residue of pyraclostrobin and its metabolite BF-500-3 in maize under field conditions were investigated. A sensitive, simple and fast method for simultaneous determination of pyraclostrobin and BF-500-3 in maize matrix was established by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The average recoveries of pyraclostrobin and BF-500-3 were found in the range of 83.6-104.9% with relative standard deviations (RSDs) of 2.3-10.0%. The results showed that pyraclostrobin dissipated quickly in maize plant with half-lives of 1.6-1.7 days. Its metabolite BF-500-3 showed a tendency of rapid increasing initially and decreasing afterwards. At harvest time, the terminal residues of pyraclostrobin were below the maximum residue limit (MRL) set by USA and Canada in maize grain when measured 7 days after the final application, which suggested that the use of this fungicide was safe for humans. The results could provide guidance to safe and reasonable use of pyraclostrobin in agriculture. Copyright © 2012 Elsevier Inc. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Tahira, Rabia; Ikram, Manzoor; Zubairy, M Suhail [Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Bougouffa, Smail [Department of Physics, Faculty of Science, Taibah University, PO Box 30002, Madinah (Saudi Arabia)
2010-02-14
We investigate the phenomenon of sudden death of entanglement in a high-dimensional bipartite system subjected to dissipative environments with an arbitrary initial pure entangled state between two fields in the cavities. We find that in a vacuum reservoir, the presence of the state where one or more than one (two) photons in each cavity are present is a necessary condition for the sudden death of entanglement. Otherwise entanglement remains for infinite time and decays asymptotically with the decay of individual qubits. For pure two-qubit entangled states in a thermal environment, we observe that sudden death of entanglement always occurs. The sudden death time of the entangled states is related to the number of photons in the cavities, the temperature of the reservoir and the initial preparation of the entangled states.
International Nuclear Information System (INIS)
Tahira, Rabia; Ikram, Manzoor; Zubairy, M Suhail; Bougouffa, Smail
2010-01-01
We investigate the phenomenon of sudden death of entanglement in a high-dimensional bipartite system subjected to dissipative environments with an arbitrary initial pure entangled state between two fields in the cavities. We find that in a vacuum reservoir, the presence of the state where one or more than one (two) photons in each cavity are present is a necessary condition for the sudden death of entanglement. Otherwise entanglement remains for infinite time and decays asymptotically with the decay of individual qubits. For pure two-qubit entangled states in a thermal environment, we observe that sudden death of entanglement always occurs. The sudden death time of the entangled states is related to the number of photons in the cavities, the temperature of the reservoir and the initial preparation of the entangled states.
Self-consistent equilibrium in a cylindrical, dissipative reverse field pinch
International Nuclear Information System (INIS)
Guo, S.C.; Paccagnella, R.
1994-01-01
One of the authors (C.L.S.) recently proposed a dissipative model to self-consistently solve the equilibrium problem in a free-boundary plasma column under cylindrical symmetry. In the present paper, on one hand the problem is strongly specialized to circular symmetry and to Ohm's and Fourier's laws without off-diagonal contributions; on the other hand, it is generalized by adding a dynamo effective electric field E d in Ohm's law, based on the standard turbulent model. This seems appropriate enough to study RFP equilibria, since it is well known that a stationary and cylindrically symmetric RFP is incompatible with a classical Ohm's law. Reasonably, only numerical solutions are expected to be accessible in general; but the further simplified problem with scalar and constant electric resistivity and constant dynamo coefficient α (E d =αB) can be solved analytically by elementary means. (author) 4 refs., 2 figs
Paramasivam, Mariappan; Deepa, Manthirachalam; Selvi, Chellamuthu; Chandrasekaran, Subramanian
2017-12-01
Dissipation kinetics of tebuconazole, trifloxystrobin and its acid metabolite residues were studied in tea under tropical field conditions using GC-MS (SIM). The average recoveries ranged from 80.7% to 105.8%, with a RSD of tea were 2.7-3.6 days for trifloxystrobin and 3.0-3.1 days for tebuconazole. The trifloxystrobin residues were not transferred into the tea infusion during the infusion process; tebuconazole did transfer, in the range of 14.3-18.9%. As the theoretical maximum residue contributions on tea from initial deposits were found to be less than the maximum permissible intake values, at the recommended application dose a withdrawal period of 23 days before consumption should be applied to reduce risk.
Wu, Chengwang; Sun, Jianqiang; Zhang, Anping; Liu, Weiping
2013-01-15
Greenhouses are increasingly important in human food supply. Pesticides used in greenhouses play important roles in horticulture; however, little is known about their behavior in greenhouse environments. This work investigates the dissipation and enantioselctive degradation of plant growth retardants including paclobutrazol and uniconazole in soils under three conditions (i.e., open field, greenhouse, and laboratory). The dissipation and enantioselective degradation of paclobutrazol and uniconazole in greenhouse were different from those in open field; they were more persistent in greenhouse than in open field soil. Leaching produced by rainfall is responsible for the difference in dissipation. Thus, local environmental impacts may occur more easily inside greenhouses, while groundwater may be more contaminated in open field. Spike concentrations of 5, 10, and 20 times the concentrations of native residues were tested for the enantioselective dissipation of the two pesticides; the most potent enantioselective degradation of paclobutrazol and uniconazole occurred at the 10 times that of the native residues in the greenhouse environments and at 20 times native residues in open field environments. The higher soil activity in greenhouses than in open fields was thought to be responsible for such a difference. The environmental risk and regulation of paclobutrazol and uniconazole should be considered at the enantiomeric level.
Dissipation and Residues of Pyrethrins in Leaf Lettuce under Greenhouse and Open Field Conditions.
Pan, Lixiang; Feng, Xiaoxiao; Zhang, Hongyan
2017-07-21
Pyrethrins are nowadays widely used for prevention and control of insects in leaf lettuce. However, there is a concern about the pesticide residue in leaf lettuce. A reliable analytical method for determination of pyrethrins (pyrethrin-and П, cinerin І and П, and jasmolin І and П) in leaf lettuce was developed by using gas chromatography-mass spectrometry (GC-MS). Recoveries of pyrethrins in leaf lettuce at three spiking levels were 99.4-104.0% with relative standard deviations of 0.9-3.1% ( n = 5). Evaluation of dissipation and final residues of pyrethrins in leaf lettuce were determined at six different locations, including the open field, as well as under greenhouse conditions. The initial concentration of pyrethrins in greenhouse (0.57 mg/kg) was higher than in open field (0.25 mg/kg) and the half-life for pyrethrins disappearance in field lettuce (0.7 days) was less than that greenhouse lettuce (1.1 days). Factors such as rainfall, solar radiation, wind speed, and crop growth rate are likely to have caused these results. The final residue in leaf lettuce was far below the maximum residue limits (MRLs) (1 mg/kg established by the European Union (EU), Australia, Korea, Japan).
Field dissipation and storage stability of glufosinate ammonium and its metabolites in soil.
Zhang, Yun; Wang, Kai; Wu, Junxue; Zhang, Hongyan
2014-01-01
A simple analytical method was developed to measure concentrations of glufosinate ammonium and its metabolites, 3-methylphosphinico-propionic acid (MPP) and 2-methylphosphinico-acetic acid (MPA), in field soil samples. To determine the minimum quantification limit, samples were spiked at different levels (0.1, 0.5, and 1.0 mg/kg). Soil samples were extracted with ammonium hydroxide solution 5% (v/v), concentrated, and reacted with trimethyl orthoacetate (TMOA) in the presence of acetic acid for derivatization. The derivatives were quantified by gas chromatography (GC) using a flame photometric detector (FPD). The linear correlation coefficients of glufosinate ammonium, MPP, and MPA in soil were 0.991, 0.999, and 0.999, respectively. The recoveries of this method for glufosinate ammonium, MPP, and MPA in soil were 77.2-95.5%, 98.3-100.3%, and 99.3-99.6% with relative standard deviations (RSD) of 1.8-4.1%, 0.4-1.4%, and 1.3-2.0%, respectively. Glufosinate ammonium dissipated rapidly in soil to MPA in hours and gradually degraded to MPP. The half-life of glufosinate ammonium degradation in soil was 2.30-2.93 days in an open field. In soil samples stored at -20°C glufosinate ammonium was stable for two months. The results of this study should provide guidance for the safe application of the herbicide glufosinate ammonium to agricultural products and the environment.
International Nuclear Information System (INIS)
Gung, C.Y.
1993-01-01
Energy dissipation, which is also called AC loss, of a composite multifilamentary superconducting wire is one of the most fundamental concerns in building a stable superconducting magnet. Characterization and reduction of AC losses are especially important in designing a superconducting magnet for generating transient magnetic fields. The goal of this thesis is to improve the understanding of AC-loss properties of superconducting wires developed for high-current ramp-field magnet applications. The major tasks include: (1) building an advanced AC-loss measurement system, (2) measuring AC losses of superconducting wires under simulated pulse magnet operations, (3) developing an analytical model for explaining the new AC-loss properties found in the experiment, and (4) developing a computational methodology for comparing AC losses of a superconducting wire with those of a cable for a superconducting pulse magnet. A new experimental system using an isothermal calorimetric method was designed and constructed to measure the absolute AC losses in a composite superconductor. This unique experimental setup is capable of measuring AC losses of a brittle Nb 3 Sn wire carrying high AC current in-phase with a large-amplitude pulse magnetic field. Improvements of the accuracy and the efficiency of this method are discussed. Three different types of composite wire have been measured: a Nb 3 Sn modified jelly-roll (MJR) internal-tin wire used in a prototype ohmic heating coil, a Nb 3 Sn internal-tin wire developed for a fusion reactor ohmic heating coil, and a NbTi wire developed for the magnets in a particle accelerator. The cross sectional constructions of these wires represent typical commercial wires manufactured for pulse magnet applications
Field observations of turbulent dissipation rate profiles immediately below the air-water interface
Wang, Binbin; Liao, Qian
2016-06-01
Near surface profiles of turbulence immediately below the air-water interface were measured with a free-floating Particle Image Velocimetry (PIV) system on Lake Michigan. The surface-following configuration allowed the system to measure the statistics of the aqueous-side turbulence in the topmost layer immediately below the water surface (z≈0˜15 cm, z points downward with 0 at the interface). Profiles of turbulent dissipation rate (ɛ) were investigated under a variety of wind and wave conditions. Various methods were applied to estimate the dissipation rate. Results suggest that these methods yield consistent dissipation rate profiles with reasonable scattering. In general, the dissipation rate decreases from the water surface following a power law relation in the top layer, ɛ˜z-0.7, i.e., the slope of the decrease was lower than that predicted by the wall turbulence theory, and the dissipation was considerably higher in the top layer for cases with higher wave ages. The measured dissipation rate profiles collapse when they were normalized with the wave speed, wave height, water-side friction velocity, and the wave age. This scaling suggests that the enhanced turbulence may be attributed to the additional source of turbulent kinetic energy (TKE) at the "skin layer" (likely due to micro-breaking), and its downward transport in the water column.
Field Dissipation and Storage Stability of Glufosinate Ammonium and Its Metabolites in Soil
Directory of Open Access Journals (Sweden)
Yun Zhang
2014-01-01
Full Text Available A simple analytical method was developed to measure concentrations of glufosinate ammonium and its metabolites, 3-methylphosphinico-propionic acid (MPP and 2-methylphosphinico-acetic acid (MPA, in field soil samples. To determine the minimum quantification limit, samples were spiked at different levels (0.1, 0.5, and 1.0 mg/kg. Soil samples were extracted with ammonium hydroxide solution 5% (v/v, concentrated, and reacted with trimethyl orthoacetate (TMOA in the presence of acetic acid for derivatization. The derivatives were quantified by gas chromatography (GC using a flame photometric detector (FPD. The linear correlation coefficients of glufosinate ammonium, MPP, and MPA in soil were 0.991, 0.999, and 0.999, respectively. The recoveries of this method for glufosinate ammonium, MPP, and MPA in soil were 77.2–95.5%, 98.3–100.3%, and 99.3–99.6% with relative standard deviations (RSD of 1.8–4.1%, 0.4–1.4%, and 1.3–2.0%, respectively. Glufosinate ammonium dissipated rapidly in soil to MPA in hours and gradually degraded to MPP. The half-life of glufosinate ammonium degradation in soil was 2.30–2.93 days in an open field. In soil samples stored at −20°C glufosinate ammonium was stable for two months. The results of this study should provide guidance for the safe application of the herbicide glufosinate ammonium to agricultural products and the environment.
Field Dissipation and Storage Stability of Glufosinate Ammonium and Its Metabolites in Soil
Zhang, Yun; Wang, Kai; Wu, Junxue; Zhang, Hongyan
2014-01-01
A simple analytical method was developed to measure concentrations of glufosinate ammonium and its metabolites, 3-methylphosphinico-propionic acid (MPP) and 2-methylphosphinico-acetic acid (MPA), in field soil samples. To determine the minimum quantification limit, samples were spiked at different levels (0.1, 0.5, and 1.0 mg/kg). Soil samples were extracted with ammonium hydroxide solution 5% (v/v), concentrated, and reacted with trimethyl orthoacetate (TMOA) in the presence of acetic acid for derivatization. The derivatives were quantified by gas chromatography (GC) using a flame photometric detector (FPD). The linear correlation coefficients of glufosinate ammonium, MPP, and MPA in soil were 0.991, 0.999, and 0.999, respectively. The recoveries of this method for glufosinate ammonium, MPP, and MPA in soil were 77.2–95.5%, 98.3–100.3%, and 99.3–99.6% with relative standard deviations (RSD) of 1.8–4.1%, 0.4–1.4%, and 1.3–2.0%, respectively. Glufosinate ammonium dissipated rapidly in soil to MPA in hours and gradually degraded to MPP. The half-life of glufosinate ammonium degradation in soil was 2.30–2.93 days in an open field. In soil samples stored at −20°C glufosinate ammonium was stable for two months. The results of this study should provide guidance for the safe application of the herbicide glufosinate ammonium to agricultural products and the environment. PMID:25374604
Dissipation and Residues of Dichlorprop-P and Bentazone in Wheat-Field Ecosystem
Directory of Open Access Journals (Sweden)
Xiaoxiao Feng
2016-05-01
Full Text Available Dichlorprop-P and bentazone have been widely used in the prevention and control of weeds in wheat field ecosystems. There is a concern that pesticide residues and metabolites remain on or in the wheat. Thus, the study of the determination and monitoring of their residues in wheat has important significance. A rapid, simple and reliable QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe method was modified, developed and validated for the determination of dichlorprop-P, bentazone and its metabolites (6-hydroxy-bentazone and 8-hydroxy-bentazone in wheat (wheat plants, wheat straw and grains of wheat using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS. The average recoveries of this method ranged from 72.9% to 108.7%, and the limits of quantification (LOQs were 2.5–12 μg/kg. The dissipation and final residue of four compounds in three provinces (Shandong, Jiangsu and Heilongjiang in China were studied. The trial results showed that the half-lives of dichlorprop-P and bentazone were 1.9–2.5 days and 0.5–2.4 days in wheat plants, respectively. The terminal residues in grains of wheat and wheat straw at harvest were all much below the maximum residue limit (MRL of 0.2 mg/kg for dichlorprop-P and 0.1 mg/kg for bentazone established by the European Union (EU, Regulation No. 396/2005.
Dong, Bizhang; Zhao, Qing; Hu, Jiye
2015-12-01
Residue analysis of emamectin benzoate and lufenuron in cabbage matrices and soil was developed using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and ultra high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The samples were extracted with 1% acetic acid in acetonitrile (v/v) or 1% acetic acid in acetonitrile/water (5:1, v/v) and cleaned up by dispersive solid-phase extraction. Mean recoveries and relative standard deviations (RSDs) in all samples ranged 87.8-100.0 % and 3.6-12.6% for emamectin benzoate and 87.8-104.8 % and 6.2-11.5% for lufenuron, respectively. The validated method was used to evaluate the dissipation rate of emamectin benzoate and lufenuron in cabbage and soil as well as the residual levels in harvested cabbage and soil at different preharvest intervals (PHI). The half-lives of emamectin benzoate and lufenuron were 1.08-2.70 and 1.74-5.04 days in cabbage, and 1.42-4.01 and 0.94-6.18 days in soil, respectively. The terminal residues were below the China maximum residue limits (MRLs) at 3 days for emamectin benzoate (0.1 mg kg(-1)) and European Union MRLs at 5 days for lufenuron (0.5 mg kg(-1)), which suggested that 5 days could be recommended as the PHI for the commercial formulation of emamectin benzoate and lufenuron application in the Chinese cabbage field.
Chai, L K; Mohd-Tahir, N; Hansen, S; Hansen, H C B
2009-01-01
Preventive treatment with insecticides at high dosing rates before planting of a new crop- soil drenching- is a common practice in some tropical intensive cropping systems, which may increase the risk of leaching, soil functioning, and pesticide uptake in the next crop. The degradation rates and migration of acephate and chlorpyrifos and their primary metabolites, methamidophos and 3,5,6-trichloropyridinol (TCP), have been studied in clayey red yellow podzolic (Typic Paleudults), alluvial (Typic Udorthents), and red yellow podzolic soils (Typic Kandiudults) of Malaysia under field conditions. The initial concentrations of acephate and chlorpyrifos in topsoils were found to strongly depend on solar radiation. Both pesticides and their metabolites were detected in subsoils at the deepest sampling depth monitored (50 cm) and with maximum concentrations up to 2.3 mg kg(-1) at soil depths of 10 to 20 cm. Extraordinary high dissipation rates for weakly sorbed acephate was in part attributed to preferential flow which was activated due to the high moisture content of the soils, high precipitation and the presence of conducting macropores running from below the A horizons to at least 1 m, as seen from a dye tracer experiment. Transport of chlorpyrifos and TCP which both sorb strongly to soil organic matter was attributed to macropore transport with soil particles. The half-lives for acephate in topsoils were 0.4 to 2.6 d while substantially longer half-lives of between 12.6 and 19.8 d were observed for chlorpyrifos. The transport through preferential flow of strongly sorbed pesticides is of concern in the tropics.
Huang, N. E.; Parsons, C. L.; Long, S. R.; Bliven, L. F.
1983-01-01
Wave breaking is proposed as the primary energy dissipation mechanism for the gravity wave field. The energy dissipation rate is calculated based on the statistical model proposed by Longuet-Higgins (1969) with a modification of the breaking criterion incorporating the surface stress according to Phillips and Banner (1974). From this modified model, an analytic expression is found for the wave attenuation rate and the half-life time of the wave field which depend only on the significant slope of the wave field and the ratio of friction velocity to initial wave phase velocity. These expressions explain why the freshly generated wave field does not last long, but why swells are capable of propagating long distances without substantial change in energy density. It is shown that breaking is many orders of magnitude more effective in dissipating wave energy than the molecular viscosity, if the significant slope is higher than 0.01. Limited observational data from satellite and laboratory are used to compare with the analytic results, and show good agreement.
August 1972 solar-terrestrial events: interplanetary magnetic field observations
Energy Technology Data Exchange (ETDEWEB)
Smith, E J [Jet Propulsion Lab., Pasadena, Calif. (USA)
1976-10-01
A review is presented of the interplanetary magnetic field observations acquired in early August 1972 when four solar flares erupted in McMath Plage region 1976. Measurements of the interplanetary field were obtained by Earth satellites, HEOS-2 and Explorer 41, and by Pioneers 9 and 10 which, by good fortune, were radially aligned and only 45/sup 0/ east of the Earth-Sun direction. In response to the four flares, four interplanetary shocks were seen at Earth and at Pioneer 9, which was then at a heliocentric distance of 0.78 AU. However, at Pioneer 10, which was 2.2 AU from the Sun, only two forward shocks and one reverse shock were seen. The available magnetic field data acquired in the vicinity of the shocks are presented. Efforts to identify corresponding shocks at the several locations and to deduce their velocities of propagation between 0.8 and 2.2 AU are reviewed. The early studies were based on average velocities between the Sun and Pioneer 9, the Sun and Earth and the Sun and Pioneer 10. A large deceleration of the shocks between the Sun and 0.8 AU as well as between 0.8 and 2.2 AU was inferred. More recently the local velocities of the shocks at Pioneers 9 and 10 have become available. A comparision of these velocities shows little, if any, deceleration between 0.8 and 2.2 AU and implies that most or all of the deceleration actually occurred nearer the Sun. Evidence is also presented that shows a significant departure of the flare-generated shock fronts from spherical symmetry.
Blaysat, Benoît
2012-05-18
Using enriched data such as displacement fields obtained from digital image correlation is a pathway to the local identification of material parameters. Up to now, most of the identification techniques for nonlinear models are based on Finite Element Updating Methods. This article explains how an appropriate use of the Dissipation Gap Method can help in this context and be an interesting alternative to these classical techniques. The Dissipation Gap Methods rely on the concept of error in dissipation that has been used mainly for the verification of finite element simulations. We provide here an original application of these founding developments to the identification of material parameters for nonlinear behaviors. The proposed technique and especially the main technical keypoint of building the admissible fields are described in detail. The approach is then illustrated through the identification of heterogeneous isotropic elasto-plastic properties. The basic numerical features highlighted through these simple examples demonstrate this approach to be a promising tool for nonlinear identification. © 2012 John Wiley & Sons, Ltd.
Ryczkowski, P.; Närhi, M.; Billet, C.; Merolla, J.-M.; Genty, G.; Dudley, J. M.
2018-04-01
Dissipative solitons are remarkably localized states of a physical system that arise from the dynamical balance between nonlinearity, dispersion and environmental energy exchange. They are the most universal form of soliton that can exist, and are seen in far-from-equilibrium systems in many fields, including chemistry, biology and physics. There has been particular interest in studying their properties in mode-locked lasers, but experiments have been limited by the inability to track the dynamical soliton evolution in real time. Here, we use simultaneous dispersive Fourier transform and time-lens measurements to completely characterize the spectral and temporal evolution of ultrashort dissipative solitons as their dynamics pass through a transient unstable regime with complex break-up and collisions before stabilization. Further insight is obtained from reconstruction of the soliton amplitude and phase and calculation of the corresponding complex-valued eigenvalue spectrum. These findings show how real-time measurements provide new insights into ultrafast transient dynamics in optics.
Wei, Ran; Ni, Jinzhi; Li, Xiaoyan; Chen, Weifeng; Yang, Yusheng
2017-03-01
Pot experiments were used to compare the dissipation and phytoremediation effect of alfalfa (Medicago sativa L.) for polycyclic aromatic hydrocarbons (PAHs) in a freshly spiked soil and two field-contaminated soils with different soil organic carbon (SOC) contents (Anthrosols, 1.41% SOC; Phaeozems, 8.51% SOC). In spiked soils, the dissipation rates of phenanthrene and pyrene were greater than 99.5 and 94.3%, respectively, in planted treatments and 95.0 and 84.5%, respectively, in unplanted treatments. In field-contaminated Anthrosols, there were limited but significant reductions of 10.2 and 15.4% of total PAHs in unplanted and planted treatments, respectively. In field-contaminated Phaeozems, there were no significant reductions of total PAHs in either unplanted or planted treatments. A phytoremediation effect was observed for the spiked soils and the Anthrosols, but not for the Phaeozems. The results indicated that laboratory tests with spiked soils cannot reflect the real state of field-contaminated soils. Phytoremediation efficiency of PAHs in field-contaminated soils was mainly determined by the content of SOC. Phytoremediation alone has no effect on the removal of PAHs in field-contaminated soils with high SOC content.
Determining Symmetry Properties of Gravitational Fields of Terrestrial Group Planets
Directory of Open Access Journals (Sweden)
R.A. Kascheev
2016-09-01
Full Text Available Numerous models of gravity fields of the Solar system bodies have been constructed recently owing to successful space missions. These models are sets of harmonic coefficients of gravity potential expansion in series of spherical functions, which is Laplace series. The sets of coefficients are different in quantity of numerical parameters, sources and composition of the initial observational data, methods to obtain and process them, and, consequently, in a variety of properties and accuracy characteristics. For this reason, the task of comparison of different models of celestial bodies considered in the paper is of interest and relevant. The main purpose of this study is comparison of the models of gravitational potential of the Earth, Moon, Mars, and Venus with the quantitative criteria of different types of symmetries developed by us. It is assumed that some particular symmetry of the density distribution function of the planetary body causes similar symmetry of its gravitational potential. The symmetry of gravitational potential, in its turn, imposes additional conditions (restrictions, which must be satisfied by the harmonic coefficients. The paper deals with seven main types of symmetries: central, axial, two symmetries specular relative to the equatorial planes and prime meridian, as well as three rotational symmetries (at π angle around the coordinate system axes. According to the results of calculations carried out for the Earth, Moon, Mars, and Venus, the values of the criteria vary considerably for different types of symmetries and for different planets. It means that the specific value of each criterion corresponding to a particular celestial body is indicative of the properties and internal structure characteristics of the latter and, therefore, it can be used as a tool for comparative planetology. On the basis of the performed calculations, it is possible to distinguish two groups of celestial bodies having similar properties of
Klinkusch, Stefan; Tremblay, Jean Christophe
2016-05-14
In this contribution, we introduce a method for simulating dissipative, ultrafast many-electron dynamics in intense laser fields. The method is based on the norm-conserving stochastic unraveling of the dissipative Liouville-von Neumann equation in its Lindblad form. The N-electron wave functions sampling the density matrix are represented in the basis of singly excited configuration state functions. The interaction with an external laser field is treated variationally and the response of the electronic density is included to all orders in this basis. The coupling to an external environment is included via relaxation operators inducing transition between the configuration state functions. Single electron ionization is represented by irreversible transition operators from the ionizing states to an auxiliary continuum state. The method finds its efficiency in the representation of the operators in the interaction picture, where the resolution-of-identity is used to reduce the size of the Hamiltonian eigenstate basis. The zeroth-order eigenstates can be obtained either at the configuration interaction singles level or from a time-dependent density functional theory reference calculation. The latter offers an alternative to explicitly time-dependent density functional theory which has the advantage of remaining strictly valid for strong field excitations while improving the description of the correlation as compared to configuration interaction singles. The method is tested on a well-characterized toy system, the excitation of the low-lying charge transfer state in LiCN.
Energy Technology Data Exchange (ETDEWEB)
Klinkusch, Stefan; Tremblay, Jean Christophe [Institute for Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin (Germany)
2016-05-14
In this contribution, we introduce a method for simulating dissipative, ultrafast many-electron dynamics in intense laser fields. The method is based on the norm-conserving stochastic unraveling of the dissipative Liouville-von Neumann equation in its Lindblad form. The N-electron wave functions sampling the density matrix are represented in the basis of singly excited configuration state functions. The interaction with an external laser field is treated variationally and the response of the electronic density is included to all orders in this basis. The coupling to an external environment is included via relaxation operators inducing transition between the configuration state functions. Single electron ionization is represented by irreversible transition operators from the ionizing states to an auxiliary continuum state. The method finds its efficiency in the representation of the operators in the interaction picture, where the resolution-of-identity is used to reduce the size of the Hamiltonian eigenstate basis. The zeroth-order eigenstates can be obtained either at the configuration interaction singles level or from a time-dependent density functional theory reference calculation. The latter offers an alternative to explicitly time-dependent density functional theory which has the advantage of remaining strictly valid for strong field excitations while improving the description of the correlation as compared to configuration interaction singles. The method is tested on a well-characterized toy system, the excitation of the low-lying charge transfer state in LiCN.
Directory of Open Access Journals (Sweden)
Yidong Xu
2017-07-01
Full Text Available In this paper, a novel method based on the Poggio–Miller–Chang-Harrington–Wu–Tsai (PMCHWT integral equation is presented to study the electromagnetic fields excited by vertical or horizontal electric dipoles in the presence of a layered region which consists of K-layered dissipative media and the air above. To transform the continuous integral equation into a block tridiagonal matrix with the feature of convenient solution, the Rao–Wilton–Glisson (RWG functions are introduced as expansion and testing functions. The electromagnetic fields excited by an electric dipole are calculated and compared with the available results, where the electric dipole antenna is buried in the non-planar air–sea–seabed, air–rock–earth–mine, and multilayered sphere structures. The analysis and computations demonstrate that the method exhibits high accuracy and solving performance in the near field propagation region.
Dissipation and residues of emamectin benzoate study in paddy under field conditions.
Li, Minghui; Chen, Weitao; Li, Mengyi; Han, Lijun
2011-12-01
The objective of this experiment was not only to provide a simple residue analytical method to evaluate the safe application rate of Emamectin Benzoate for paddy crops but also to give a suitable recommended dosage in paddy crops. Paddy samples were detected using HPLC-MS/MS. The half-lives of emamectin benzoate in paddy plants, water and soil were 2.04-8.66 days, 2.89-4.95 days and 3.65-5.78 days with a dissipation rate of 90% over 7 days after application, respectively. Low residues and short half-life suggested that Emamectin Benzoate could be safely used in paddy crops with the suitable dosage and application.
Buddidathi, Radhika; Mohapatra, Soudamini; Siddamallaiah, Lekha; Manikrao, Gourishankar; Hebbar, Shibara Shankara
2016-01-01
This investigation was undertaken to compare the dissipation pattern of flubendiamide in capsicum fruits under poly-house and open field after giving spray applications at the recommended and double doses of 48 g a.i. ha(-1) and 96 g a.i. ha(-1). Extraction and purification of capsicum fruit samples were carried out by the QuEChERS method. Residues of flubendiamide and its metabolite, des-iodo flubendiamide, were analyzed by high-performance liquid chromatography-photodiode array, and confirmed by liquid chromatography-mass spectrometry/mass spectrometry. Limit of quantification of the method was 0.05 mg kg(-1), and recovery of the insecticides was in the range of 89.6-104.3%, with relative standard deviation being 4.5-11.5%. The measurement uncertainty of the analytical method was in the range of 10.7-15.7%. Initial residue deposits of flubendiamide on capsicum fruits grown under poly-house conditions were (0.977 and 1.834 mg kg(-1)) higher than that grown in the field (0.665 and 1.545 mg kg(-1)). Flubendiamide residues persisted for 15 days in field-grown and for 25 days in poly-house-grown capsicum fruits. The residues were degraded with the half-lives of 4.3-4.7 and 5.6-6.6 days in field and poly-house respectively. Des-iodo flubendiamide was not detected in capsicum fruits or soil. The residues of flubendiamide degraded to below the maximum residue limit notified by Codex Alimentarius Commission (FAO/WHO) after 1 and 6 days in open field, and 3 and 10 days in poly-house. The results of the study indicated that flubendiamide applied to capsicum under controlled environmental conditions required longer pre-harvest interval to allow its residues to dissipate to the safe level.
Dissipation and residue behavior of emamectin benzoate on apple and cabbage field application.
Wang, Lei; Zhao, Pengyue; Zhang, Fengzu; Li, Yanjie; Du, Fengpei; Pan, Canping
2012-04-01
A LC-ESI-MS/MS method with QuEChERS for analysis of emamectin benzoate in cabbage, apple and soil was established. At fortification levels of 0.001, 0.01 and 0.1 mg/kg in cabbage, apple and soil, it was shown that recoveries ranged from 75.9 to 97.0 percent with relative standard deviation (RSD) of 4.4-19.0 percent. The limit of quantiﬁcation (LOQ) was 0.001 mg/kg for cabbage, apple and soil. The dissipation half-lives of emamectin benzoate in cabbage, apple and soil were 1.34-1.72 day, 2.75-3.09 day and 1.89-4.89 day, respectively. The ﬁnal residues of emamectin benzoate ranged from 0.001 to 0.052 mg/kg in cabbages, 0.003 to 0.090 mg/kg in apples and 0.001 to 0.089 mg/kg in soils, respectively. Therefore, it would be unlikely to cause health problems if emamectin benzoate was applied according to the use pattern suggested by the manufactures on the label. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.
Dissipation behavior and risk assessment of butralin in soybean and soil under field conditions.
Li, Congdi; Liu, Rong; Li, Li; Li, Wei; He, Yujian; Yuan, Longfei
2017-08-29
Dissipation behavior, final residue, and risk assessment of butralin in soybean, green soybean, plant, and soil were investigated. Butralin residues were extracted with acetonitrile and then soybean samples were detected with gas chromatography-mass spectrometer (GC-MS) and soil samples were determined with GC with nitrogen phosphorous detector (GC-NPD). The limit of quantification (LOQ) of the method was 0.01 mg/kg for soybean, green soybean, plant, and soil. Average recoveries ranged from 90.4 ~ 98.2% for green soybean, 86.2 ~ 86.6% for soybean, 86.0 ~ 98.8% for plant, and 85.0 ~ 106.8% for soil. The relative standard deviations (RSDs) were 2.0 ~ 7.2% for green soybean, 2.0 ~ 3.0% for soybean, 3.1 ~ 8.1% for plant, and 1.8 ~ 6.6% for soil. Half-lives of butralin in soil samples varied in the range of 11-22 days. At harvest time, final residues of butralin in soybean and green soybean were lower than LOQ. Risk assessment demonstrated that, at recommended dosage and frequency, butralin would not induce significant harm on humans. The study could be used as a quantitative basis for application of butralin on soybean.
Anomalous growth and dissipation of the magnetic field in a turbulent flow with stretches
Energy Technology Data Exchange (ETDEWEB)
Gvaramadze, V V; Lominadze, J G; Ruzmaikin, A A; Sokolov, D D
1987-04-01
The magnetic field evolution in helical turbulence with stretches is investigated. It is shown that heavy concentrations of the magnetic field appear under definite conditions. The results are consistent with numerical experiments.
Anomalous growth and dissipation of the magnetic field in a turbulent flow with stretches
International Nuclear Information System (INIS)
Gvaramadze, V.V.; Lominadze, J.G.; Ruzmaikin, A.A.; Sokolov, D.D.
1987-01-01
The magnetic field evolution in helical turbulence with stretches is investigated. It is shown that heavy concentrations of the magnetic field appear under definite conditions. The results are consistent with numerical experiments
Tang, Yundong; Flesch, Rodolfo C. C.; Jin, Tao
2017-07-01
Magnetic nanoparticle (MNP) hyperthermia is a promising emerging therapy for cancer treatment that is minimally invasive and has been successfully used to treat different types of tumors. The power dissipation of MNPs, which is one of the most important factors during a hyperthermia treatment, is determined by the properties of MNPs and characteristics of the magnetic field. This paper proposes a method based on the finite element analysis for determining the value of the power dissipation of particles (PDP) that can maximize the average temperature of the tumor during treatment and at the same time guarantee that the maximum temperature is within the therapeutic range. The application of the critical PDP value can improve the effectiveness of the treatment since it increases the average temperature in the tumor region while limiting the damage to the healthy tissue that surrounds it. After the critical PDP is determined for a specific model, it is shown how the properties of the MNPs can be chosen to achieve the desired PDP value. The transient behavior of the temperature distribution for two different models considering blood vessels is analyzed as a case study, showing that the presence of a blood vessel inside the tumor region can significantly decrease the uniformity of the temperature field and also increase the treatment duration given its cooling effects. To present a solution that does not depend upon a good model of the tumor region, an alternative method that uses MNPs with low Curie temperature is proposed, given the temperature self-regulating properties of such MNPs. The results demonstrate that the uniformity of the temperature field can be significantly increased by combining the optimization procedure proposed in this paper with the use of low-Curie-temperature MNPs.
Energy Technology Data Exchange (ETDEWEB)
Lacroix, D
2001-07-01
In this work, we introduce a method to reduce the microscopic mean-field theory to a classical macroscopic dynamics at the initial stage of fusion reaction. We show that TDHF (Time-dependent Hartree-Fock) could be a useful tool to infer information on the fusion barrier as well as on one-body dissipation effect. We apply the reduction of information to the case of head-on reaction between a {sup 16}O and {sup 16,22,24,28}O in order to quantify the effect of neutron skin on fusion. We show that the precise determination of fusion barrier requires, in addition to the relative distance between center of mass, the introduction of an additional collective coordinate that explicitly breaks the neutron-proton symmetry. With this additional collective variable, we obtain a rather precise determination of the barrier position, height and diffuseness as well as one-body friction. (author)
Characterizing Tropical Forest Structure using Field-based Measurements and a Terrestrial Lidar
Palace, M. W.; Sullivan, F.; Ducey, M. J.; Herrick, C.
2015-12-01
Forest structure comprises numerous quantifiable components of forest biometric characteristics, one of which is tree architecture. This structural component is important in the understanding of the past and future trajectories of these biomes. Tropical forests are often considered the most structurally complex and yet least understood of forested ecosystems. New technologies have provided novel avenues for quantifying properties of forested ecosystems, one of which is LIght Detection And Ranging (lidar). This sensor can be deployed on satellite, aircraft, unmanned aerial vehicles, and terrestrial platforms. In this study we examined the efficacy of a terrestrial lidar scanner (TLS) system in a tropical forest to estimate forest structure. Our study was conducted in January 2012 at La Selva, Costa Rica at twenty locations in predominantly undisturbed forest. At these locations we collected field measured biometric attributes using a variable plot design. We also collected TLS data from the center of each plot. Using this data we developed relative vegetation profiles (RVPs) and calculated a series of parameters including entropy, FFT, number of layers and plant area index to develop statistical relationships with field data. We developed statistical models using multiple linear regressions, all of which converged on statistically significant relationships with the strongest relationship being for mean crown depth (r2 = 0.87, p information on tropical forest structure.
Energy Technology Data Exchange (ETDEWEB)
Trément, Sébastien; Rousseau, Bernard, E-mail: bernard.rousseau@u-psud.fr [Laboratoire de Chimie-Physique, UMR 8000 CNRS, Université Paris-Sud, Orsay (France); Schnell, Benoît; Petitjean, Laurent; Couty, Marc [Manufacture Française des Pneumatiques MICHELIN, Centre de Ladoux, 23 place des Carmes, 63000 Clermont-Ferrand (France)
2014-04-07
We apply operational procedures available in the literature to the construction of coarse-grained conservative and friction forces for use in dissipative particle dynamics (DPD) simulations. The full procedure rely on a bottom-up approach: large molecular dynamics trajectories of n-pentane and n-decane modeled with an anisotropic united atom model serve as input for the force field generation. As a consequence, the coarse-grained model is expected to reproduce at least semi-quantitatively structural and dynamical properties of the underlying atomistic model. Two different coarse-graining levels are studied, corresponding to five and ten carbon atoms per DPD bead. The influence of the coarse-graining level on the generated force fields contributions, namely, the conservative and the friction part, is discussed. It is shown that the coarse-grained model of n-pentane correctly reproduces self-diffusion and viscosity coefficients of real n-pentane, while the fully coarse-grained model for n-decane at ambient temperature over-predicts diffusion by a factor of 2. However, when the n-pentane coarse-grained model is used as a building block for larger molecule (e.g., n-decane as a two blobs model), a much better agreement with experimental data is obtained, suggesting that the force field constructed is transferable to large macro-molecular systems.
International Nuclear Information System (INIS)
Hnat, B.; O’Connell, D.; Nakariakov, V. M.; Sundberg, T.
2016-01-01
We obtain dispersion relations of magnetic field fluctuations for two crossings of the terrestrial foreshock by Cluster spacecraft. These crossings cover plasma conditions that differ significantly in their plasma β and in the density of the reflected ion beam, but not in the properties of the encountered ion population, both showing shell-like distribution function. Dispersion relations are reconstructed using two-point instantaneous wave number estimations from pairs of Cluster spacecraft. The accessible range of wave vectors, limited by the available spacecraft separations, extends to ≈2 × 10 4 km. Results show multiple branches of dispersion relations, associated with different powers of magnetic field fluctuations. We find that sunward propagating fast magnetosonic waves and beam resonant modes are dominant for the high plasma β interval with a dense beam, while the dispersions of the interval with low beam density include Alfvén and fast magnetosonic modes propagating sunward and anti-sunward.
Energy Technology Data Exchange (ETDEWEB)
Hnat, B.; O’Connell, D.; Nakariakov, V. M. [Centre for Fusion, Space and Astrophysics, University of Warwick (United Kingdom); Sundberg, T., E-mail: B.Hnat@warwick.ac.uk [School of Physics and Astronomy, Queen Mary University of London (United Kingdom)
2016-08-20
We obtain dispersion relations of magnetic field fluctuations for two crossings of the terrestrial foreshock by Cluster spacecraft. These crossings cover plasma conditions that differ significantly in their plasma β and in the density of the reflected ion beam, but not in the properties of the encountered ion population, both showing shell-like distribution function. Dispersion relations are reconstructed using two-point instantaneous wave number estimations from pairs of Cluster spacecraft. The accessible range of wave vectors, limited by the available spacecraft separations, extends to ≈2 × 10{sup 4} km. Results show multiple branches of dispersion relations, associated with different powers of magnetic field fluctuations. We find that sunward propagating fast magnetosonic waves and beam resonant modes are dominant for the high plasma β interval with a dense beam, while the dispersions of the interval with low beam density include Alfvén and fast magnetosonic modes propagating sunward and anti-sunward.
Field Dissipation and Storage Stability of Glufosinate Ammonium and Its Metabolites in Soil
Zhang, Yun; Wang, Kai; Wu, Junxue; Zhang, Hongyan
2014-01-01
A simple analytical method was developed to measure concentrations of glufosinate ammonium and its metabolites, 3-methylphosphinico-propionic acid (MPP) and 2-methylphosphinico-acetic acid (MPA), in field soil samples. To determine the minimum quantification limit, samples were spiked at different levels (0.1, 0.5, and 1.0 mg/kg). Soil samples were extracted with ammonium hydroxide solution 5% (v/v), concentrated, and reacted with trimethyl orthoacetate (TMOA) in the presence of acetic acid f...
Static terrestrial laser scanning of juvenile understory trees for field phenotyping
Wang, Huanhuan; Lin, Yi
2014-11-01
This study was to attempt the cutting-edge 3D remote sensing technique of static terrestrial laser scanning (TLS) for parametric 3D reconstruction of juvenile understory trees. The data for test was collected with a Leica HDS6100 TLS system in a single-scan way. The geometrical structures of juvenile understory trees are extracted by model fitting. Cones are used to model trunks and branches. Principal component analysis (PCA) is adopted to calculate their major axes. Coordinate transformation and orthogonal projection are used to estimate the parameters of the cones. Then, AutoCAD is utilized to simulate the morphological characteristics of the understory trees, and to add secondary branches and leaves in a random way. Comparison of the reference values and the estimated values gives the regression equation and shows that the proposed algorithm of extracting parameters is credible. The results have basically verified the applicability of TLS for field phenotyping of juvenile understory trees.
Green Ocean Amazon 2014/15 Terrestrial Ecosystem Project (Geco) Field Campaign Report
Energy Technology Data Exchange (ETDEWEB)
Jardine, Kolby [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2016-06-01
In conjunction with the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility GoAmazon campaign, the Terrestrial Ecosystem Science (TES)-funded Green Ocean Amazon (GoAmazon 2014/15) terrestrial ecosystem project (Geco) was designed to: • evaluate the strengths and weaknesses of leaf-level algorithms for biogenic volatile organic compounds (BVOCs) emissions in Amazon forests near Manaus, Brazil, and • conduct mechanistic field studies to characterize biochemical and physiological processes governing leaf- and landscape-scale tropical forest BVOC emissions, and the influence of environmental drivers that are expected to change with a warming climate. Through a close interaction between modeling and observational activities, including the training of MS and PhD graduate students, post-doctoral students, and technicians at the National Institute for Amazon Research (INPA), the study aimed at improving the representation of BVOC-mediated biosphere-atmosphere interactions and feedbacks under a warming climate. BVOCs can form cloud condensation nuclei (CCN) that influence precipitation dynamics and modify the quality of down welling radiation for photosynthesis. However, our ability to represent these coupled biosphere-atmosphere processes in Earth system models suffers from poor understanding of the functions, identities, quantities, and seasonal patterns of BVOC emissions from tropical forests as well as their biological and environmental controls. The Model of Emissions of Gases and Aerosols from Nature (MEGAN), the current BVOC sub-model of the Community Earth System Model (CESM), was evaluated to explore mechanistic controls over BVOC emissions. Based on that analysis, a combination of observations and experiments were studied in forests near Manaus, Brazil, to test existing parameterizations and algorithm structures in MEGAN. The model was actively modified as needed to improve tropical BVOC emission simulations on
Electron Acceleration by Stochastic Electric Fields in Thunderstorms: Terrestrial Gamma-Ray Flashes
Alnussirat, S.; Miller, J. A.; Christian, H. J., Jr.; Fishman, G. J.
2016-12-01
Terrestrial gamma-ray flashes (TGFs) are energetic pulses of photons, which are intense and short, originating in the atmosphere during thunderstorm activity. Despite the number of observations, the production mechanism(s) of TGFs and other energetic particles is not well understood. However, two mechanisms have been suggested as a source of TGFs: (1) the relativistic runaway electron avalanche mechanism (RREA), and (2) the lightning leader mechanism. The RREA can account for the TGF observations, but requires restrictive or unrealistic assumptions. The lightning leader channel is also expected to produce runaway electrons, but through inhomogeneous, small scale, strong electric fields. In this work we use the Boltzmann equation to model the electron acceleration by the lightning leader mechanism, and we derive the gamma-ray spectrum from the electron distribution function. The electric fields at the tip of the leaders are assumed to be stochastic in space and time. Since the physics involved in the lightening leader is not known, we test different cases of the stochastic acceleration agent. From this modeling we hope to investigate the possibility and efficiency of stochastic acceleration in thunderstorm.
Field studies on the terrestrial behavior of actinide elements in East Tennessee
International Nuclear Information System (INIS)
Garten, C.T. Jr.; Bondietti, E.A.; Trabalka, J.R.; Walker, R.L.; Scott, T.G.
1984-01-01
Field studies on the comparative uptake of various actinide elements ( 232 Th, 233 U, 238 U, 239 Pu, 241 Am, and 244 Cm) by plants and animals inhabiting historically contaminated environments on the Oak Ridge National Laboratory (ORNL) reservation in East Tennessee are summarized. The present-day pattern of actinide element bioaccumulation from a flood plain site contaminated with Pu in 1944 is U > Th approx. Pu. Thus the environmentally dispersed 239 Pu exhibits a transfer from floodplain soil to biota comparable to that of indigenous 232 Th and less than that of the indigenous 238 U. This ranking agrees with the chemical extractability of U, Th, and Pu from soil, using either weak acids or strongly basic reagents. The pattern of actinide element uptake from the shoreline of a historically contaminated pond is Pu 238 U = 233 U. This ranking also agrees with the chemical extractability of Pu, Am, Cm, and U from shoreline sediment, using weak acids. Results from field studies at ORNL agree with what has been generally inferred about the relative food chain transfer of the actinides, based on laboratory studies and field studies at other sites in the United States. Because they share the same valence state, there are apparent strong similarities in soil sorption, plant uptake, and animal uptake between trivalent Am and Cm and between tetravalent Pu and Th. Available evidence suggests that knowledge of the behavior of naturally occurring 232 Th in the terrestrial food chain can be useful for predicting the long-term fate of environmentally dispersed 239 Pu, while data on 238 U might be used to place an upper limit on the expected long-term food chain transfer of all transuranic elements except Np. 33 references, 5 figures, 1 table
Dissipation and degradation of /sup 14/C-DDT in Potohar area Islamabad soil under field conditions
International Nuclear Information System (INIS)
Hussain, A.; Asi, M.R.; Iqbal, Z.; Muhammad, A.; Khan, T.A.
2002-01-01
An experiment was conducted in Potohar area, Islamabad for one and half year period to investigate the dissipation and degradation of /sup 14/C-DDT in soil The study revealed that binding of /sup 14/C-DDT to the soil increased gradually with the passage of time. The extractable residues decreased in the same period. Results also indicated that /sup 14/C-DDT dissipated more rapidly in this environment as compared to the temperate regions. The overall half-life of DDT was 260 days. (author)
Weiss, Ulrich
2008-01-01
Major advances in the quantum theory of macroscopic systems, in combination with stunning experimental achievements, have brightened the field and brought it to the attention of the general community in natural sciences. Today, working knowledge of dissipative quantum mechanics is an essential tool for many physicists. This book - originally published in 1990 and republished in 1999 as an enlarged second edition - delves much deeper than ever before into the fundamental concepts, methods, and applications of quantum dissipative systems, including the most recent developments. In this third edi
International Nuclear Information System (INIS)
Chernousenko, V.M.; Kuklin, V.M.; Panachenko, I.P.; Vorob'yov, V.M.
1990-01-01
This paper reports on a wide spectrum of oscillations that is excited due to the evolution instabilities, being in a weak above-threshold state, in the inequilibrium media with decaying spectrum. In this case the pumping, whose part is played by an intensive wave or occupation inversion in the active medium, synchronized the phases of excited modes and, thus, forms the space dissipative structure of the field. In dissipative nonlinear media with nondecaying spectrum the space structures, formed due to the development of instability, experience small-scale hexagonal modulation
Directory of Open Access Journals (Sweden)
Mehmet Camurdan
1998-01-01
are coupled by appropriate trace operators. This overall model differs from those previously studied in the literature in that the elastic chamber floor is here more realistically modeled by a hyperbolic Kirchoff equation, rather than by a parabolic Euler-Bernoulli equation with Kelvin-Voight structural damping, as in past literature. Thus, the hyperbolic/parabolic coupled system of past literature is replaced here by a hyperbolic/hyperbolic coupled model. The main result of this paper is a uniform stabilization of the coupled PDE system by a (physically appealing boundary dissipation.
Energy Technology Data Exchange (ETDEWEB)
Duret, D.
1994-12-31
After a presentation of the terrestrial magnetic field and its various anomalies, the different types of magnetometers commonly used are reviewed with their characteristics and performances: scalar magnetometers (free precession and continuous polarization proton magnetometers, dynamic polarization proton magnetometers, optical pumping magnetometers, electronic resonance scalar magnetometers (without pumping)); vectorial magnetometers (flux gate magnetometers, induction magnetometers, suspended magnet magnetometers, superconducting magnetometers, integrated magnetometers, resonance directional magnetometers). The magnetometry market and applications are discussed. 20 figs., 9 tabs., 72 refs.
International Nuclear Information System (INIS)
Ezz El-Arab, A.; Mostafa, I.Y.
1991-01-01
The rates of dissipation and degradation of the insecticides DDT and parathion were studied under field conditionsm using 14 C-labelled chemicals. Over a period of 12 weeks, extractable, soil-bound and total 14 C-activity were recorded. In case of DDT, dissipation of 14 C-activity from soil showed a continuous and gradual increase reaching about 30% after 8 weeks and remained constant up to 12 weeks. The formation of DDE as a principal metabolite seems to be increasing with time ans accounted for approximately 25% of the extractable residues after 12 weeks. There was also a gradual significant increase in the formation of soil 14 C-bound residues which reached 12% of the total residues after the same period. On the other hand, parathion dissipation from the soil under the same conditions did not exceed 10% up to 12 weeks. The amount of 14 C-bound residues was found to contribute 33% of the applied dose. Analysis of the extractable fraction revealed that parathion was partly degraded by soil microorganisms into p-amino phenol, p-nitrophenol, paraoxon, amino parathion and aminoparaoxon in different percentages depending on the depth of soil. 2 fig.,1 tab
Field evidence for transfer of plastic debris along a terrestrial food chain
Huerta Lwanga, Esperanza; Mendoza Vega, Jorge; Ku Quej, Victor; Angeles Chi, de los Jesus; Sanchez del Cid, Lucero; Chi, Cesar; Escalona Segura, Griselda; Gertsen, Henny; Salánki, Tamás; Ploeg, van der Martine; Koelmans, Bart; Geissen, Violette
2017-01-01
Although plastic pollution happens globally, the micro- (<5 mm) and macroplastic (5–150 mm) transfer of plastic to terrestrial species relevant to human consumption has not been examined. We provide first-time evidence for micro- and macroplastic transfer from soil to chickens in traditional
Czech Academy of Sciences Publication Activity Database
DeSimone, A.; Kružík, Martin
2013-01-01
Roč. 8, č. 2 (2013), s. 481-499 ISSN 1556-1801 R&D Projects: GA ČR(CZ) GAP201/12/0671 Institutional support: RVO:67985556 Keywords : hysteresis * shape memory Subject RIV: BA - General Mathematics Impact factor: 0.952, year: 2013 http://library.utia.cas.cz/separaty/2013/MTR/kruzik-domain patterns and hysteresis in phase-transforming solids analysis and numerical simulations of a sharp interface dissipative model via phase-field approximation.pdf
International Nuclear Information System (INIS)
Nalesso, G.F.; Jacobson, A.R.
1988-01-01
We study the interaction of a plasma cloud, jetting across the geomagnetic field with the surrounding ionosphere. The cloud is assumed of finite extension in the direction normal to both the direction of motion and the magnetic field, while the ionosphere is considered a collisional anisotropic magnetized plasma. It is shown that two main mechanisms contribute to the cloud's braking: momentum exchange with the ionosphere via Alfven waves and momentum dissipation due to resistive currents. Due to the finite size of the cloud a differential braking of the different transverse harmonics of the Alfven wave appears when the momentum exchange mechanism is dominant. The result is a sharpening of the cloud's velocity field. copyright American Geophysical Union 1988
Field evidence for transfer of plastic debris along a terrestrial food chain
Huerta Lwanga, Esperanza; Mendoza Vega, Jorge; Ku Quej, Victor; Chi, Jesus de los Angeles; Sanchez del Cid, Lucero; Chi, Cesar; Escalona Segura, Griselda; Gertsen, Henny; Salánki, Tamás; van der Ploeg, Martine; Koelmans, Albert A.; Geissen, Violette
2017-01-01
Although plastic pollution happens globally, the micro- (<5 mm) and macroplastic (5–150 mm) transfer of plastic to terrestrial species relevant to human consumption has not been examined. We provide first-time evidence for micro- and macroplastic transfer from soil to chickens in traditional Mayan home gardens in Southeast Mexico where waste mismanagement is common. We assessed micro- and macroplastic in soil, earthworm casts, chicken feces, crops and gizzards (used for human consumption)....
International Nuclear Information System (INIS)
Pande, D.C.; Agarwal, D.C.
1982-01-01
This paper presents a review about terrestrial magnetosphere. During the last few years considerable investigation have been carried out about the properties of Solar Wind and its interaction with planetary magnetic fields. It is therefore of high importance to accumulate all the investigations in a comprehensive form. The paper reviews the property of earth's magnetosphere, magnetosheath, magneto pause, polar cusps, bow shook and plasma sheath. (author)
Wei, Ran; Ni, Jinzhi; Chen, Weifeng; Yang, Yusheng
2017-10-01
Soil organic matter (SOM) is the main adsorbent for polycyclic aromatic hydrocarbons (PAHs) and the principal aggregating agent for soil aggregation that can affect PAH bioavailability and bioaccessibility in soils. The objective of this study was to analyze the relationship between PAH dissipation and variation in soil aggregate-size distribution in two field-contaminated soils with different soil organic C (SOC) content (Anthrosols, 1.41% SOC; Phaeozems, 8.51% SOC) in phytoremediation with alfalfa. The results showed that there were significant reductions of 10.2 and 15.4% of the total PAHs in unplanted and planted treatments, respectively, for Anthrosols. However, there was no significant reduction of total PAHs in either unplanted or planted treatment for Phaeozems. For Anthrosols, mass percentages of coarse sand and fine sand were significantly reduced while coarse silt and fine silt were significantly increased for the planted soil compared to the initial soil (p soil was slightly reduced. The main reason for the dissipation of PAHs in Anthrosols could be that macroaggregates were broken into microaggregates, which made some trapped PAHs become bioaccessible to soil microorganisms.
Field evidence for transfer of plastic debris along a terrestrial food chain.
Huerta Lwanga, Esperanza; Mendoza Vega, Jorge; Ku Quej, Victor; Chi, Jesus de Los Angeles; Sanchez Del Cid, Lucero; Chi, Cesar; Escalona Segura, Griselda; Gertsen, Henny; Salánki, Tamás; van der Ploeg, Martine; Koelmans, Albert A; Geissen, Violette
2017-10-26
Although plastic pollution happens globally, the micro- (plastic to terrestrial species relevant to human consumption has not been examined. We provide first-time evidence for micro- and macroplastic transfer from soil to chickens in traditional Mayan home gardens in Southeast Mexico where waste mismanagement is common. We assessed micro- and macroplastic in soil, earthworm casts, chicken feces, crops and gizzards (used for human consumption). Microplastic concentrations increased from soil (0.87 ± 1.9 particles g -1 ), to earthworm casts (14.8 ± 28.8 particles g -1 ), to chicken feces (129.8 ± 82.3 particles g -1 ). Chicken gizzards contained 10.2 ± 13.8 microplastic particles, while no microplastic was found in crops. An average of 45.82 ± 42.6 macroplastic particles were found per gizzard and 11 ± 15.3 macroplastic particles per crop, with 1-10 mm particles being significantly more abundant per gizzard (31.8 ± 27.27 particles) compared to the crop (1 ± 2.2 particles). The data show that micro- and macroplastic are capable of entering terrestrial food webs.
Lubineau, Gilles; Florentin, É ric; Moussawi, Ali; Blaysat, Benoî t
2012-01-01
The full field measurement technique has become a popular technique for the quick identification of complex and/or heterogeneous-in-space material behaviors. Based on the rich available corpus of information, this technique makes possible to identify complex evolution laws using few highly heterogeneous testing. Multiple techniques have been proposed up to now. Here, we detail the application of the constitutive error relation to the identification of linear elastic material models.Then, the natural extension of the constitutive equation gap method through a dissipation gap method is discussed for the identification of material behaviors involving dissipation. 2D reference examples are provided for each method. © 2012 EDP Sciences.
Stevens, K. M.; Krim, J.
2015-03-01
We present here a quartz crystal microbalance study of two-phase gold nickel alloys whose internal granular properties are probed by exposure to a fluctuating external magnetic field. The work is motivated by prior studies demonstrating that granular two-phase materials exhibited lower friction and wear than solid solution alloys with identical compositions. In particular, we report a ``flexing'' effect which appears when an external magnetic field is applied, and is manifested as a decrease in the magnitude of oscillation amplitude that is synchronized with the applied field; the effect is not seen on the complimentary solid solution samples. The effect is consistent with internal interfacial friction between nickel and gold grains, indicating a degree of freedom which may decrease friction even in the absence of an external magnetic field. This is supported through analysis of energy dissipation in the system, using the Butterworth-Van Dyke equivalent circuit model. Data and interpretation are also presented that rule out alternate explanations such as giant magnetoresistance and/or other resistive phenomenon within the film. Funding provided by NSF DMR0805204. Thanks to L. Pan for sample preparation.
Armston, J.; Newnham, G.; Strahler, A. H.; Schaaf, C.; Danson, M.; Gaulton, R.; Zhang, Z.; Disney, M.; Sparrow, B.; Phinn, S. R.; Schaefer, M.; Burt, A.; Counter, S.; Erb, A.; Goodwin, N.; Hancock, S.; Howe, G.; Johansen, K.; Li, Z.; Lollback, G.; Martel, J.; Muir, J.; Paynter, I.; Saenz, E.; Scarth, P.; Tindall, D.; Walker, L.; Witte, C.; Woodgate, W.; Wu, S.
2013-12-01
During 28th July - 3rd August, 2013, an international group of researchers brought five terrestrial laser scanners (TLS) to long-term monitoring plots in three eucalyptus-dominated woodland sites near Brisbane, Queensland, Australia, to acquire scans at common locations for calibration and intercomparison.They included: DWEL - a dual-wavelength full-waveform laser scanner (Boston U., U. Massachusetts Lowell, U. Massachusetts Boston, USA) SALCA - a dual-wavelength full-waveform laser scanner (U. Salford, UK) CBL - a canopy biomass lidar, a small ultraportable low-cost multiple discrete return scanner (U. Massachusetts Boston, USA) Riegl VZ400 - a survey-grade commercial waveform scanner (Queensland Government and TERN, U. Queensland, Australia) FARO Focus 3D - a lightweight commercial phase-shift ranging laser scanner (U. Southern Queensland) Two plots were scanned at Karawatha Forest Park, a Terrestrial Ecosystem Research Network (TERN) Supersite, and one plot at D'Aguilar National Park. At each 50 x 100 m plot, a center scan point was surrounded by four scan points located 25 m away in a cross pattern allowing for 3-D reconstructions of scan sites in the form of point clouds. At several center points, multiple instrument configurations (i.e. different beam divergence, angular resolution, pulse rate) were acquired to test the impact of instrument specifications on separation of woody and non-woody materials and estimation of vegetation structure parameters. Three-dimensional Photopoint photographic panoramas were also acquired, providing reconstructions of stems in the form of point clouds using photogrammetric correlation methods. Calibrated reflectance targets were also scanned to compare instrument geometric and radiometric performance. Ancillary data included hemispherical photos, TRAC LAI/clumping measurements, spectra of leaves, bark, litter, and other target components. Wet and dry leaf weights determined water content. Planned intercomparison topics and
Blaysat, Benoî t; Florentin, É ric; Lubineau, Gilles; Moussawi, Ali
2012-01-01
and especially the main technical keypoint of building the admissible fields are described in detail. The approach is then illustrated through the identification of heterogeneous isotropic elasto-plastic properties. The basic numerical features highlighted
Directory of Open Access Journals (Sweden)
M.C. Raju
2015-03-01
Full Text Available A theoretical analysis is performed to study induced magnetic field effects on free convection flow past a vertical plate. The x¯-axis is taken vertically upwards along the plate, y¯-axis normal to the plate into the fluid region. It is assumed that the plate is electrically non-conducting and the applied magnetic field is of uniform strength (H0 and perpendicular to the plate. The magnetic Reynolds number of the flow is not taken to be small enough so that the induced magnetic field is taken into account. The coupled nonlinear partial differential equations are solved by Perturbation technique and the effects of various physical parameters on velocity, temperature, and induced magnetic fields are studied through graphs and tables. Variations in Skin friction and rate of heat transfer are also studied. It is observed that an increase in magnetic parameter decreases the velocity for both water and air. It is also seen that there is a fall in induced magnetic field as magnetic Prandtl number, and magnetic field parameter increase.
International Nuclear Information System (INIS)
Riemens, Marleen M.; Dueck, Thom; Kempenaar, Corne
2008-01-01
Guidelines provided by OECD and EPPO allow the use of data obtained in greenhouse experiments in the risk assessment for pesticides to non-target terrestrial plants in the field. The present study was undertaken to investigate the predictability of effects on field-grown plants using greenhouse data. In addition, the influence of plant development stage on plant sensitivity and herbicide efficacy, the influence of the surrounding vegetation on individual plant sensitivity and of sublethal herbicide doses on the biomass, recovery and reproduction of non-crop plants was studied. Results show that in the future, it might well be possible to translate results from greenhouse experiments to field situations, given sufficient experimental data. The results also suggest consequences at the population level. Even when only marginal effects on the biomass of non-target plants are expected, their seed production and thereby survival at the population level may be negatively affected. - The response of greenhouse-grown wild plant species to herbicide exposure could be related to the response of the same species when grown in the field
Zhang, P W; Wang, S Y; Huang, C L; Fu, J T; Huang, R L; Li, Z H; Zhang, Z X
2018-01-01
The single application of 0.5 % clothianidin granules, a novel formulation, was used to control pests in vegetables under a high dose. In this article, residues of clothianidin in cabbage and soil samples under field conditions from Guangzhou, Nanning, and Qianjiang were determined by HPLC. The terminal residues of clothianidin in cabbage were less than the limit of detection (clothianidin residual, clothianidin granules and fertilizers of chicken manure, urea, and organic fertilizer were mixed into different pesticide fertilizers through their normal field using dosage and evaluate residual influence of clothianidin in different formula. After analysis of variance of the effect factors, the effect of different pesticide types on half-life was not significant, but the effect of sample types was significant. Clothianidin granules and pesticide fertilizers could be safely applied in cabbage under a single high-dose administration.
International Nuclear Information System (INIS)
Tagami, Keiko
2003-01-01
Obtaining data on 99 Tc in the rice paddy field environment is important because Tc is a redox sensitive element. The behavior of Tc is expected to be different under upland field and rice paddy field conditions since the redox conditions in the soil environment differ. However, most of the data on the nuclide behavior in soil were obtained under upland field conditions. To understand the global fallout 99 Tc distributions in soil samples collected in Japan, a simple and rapid separation method was developed in order to determine low-levels of 99 Tc in soil samples by an inductively coupled plasma mass spectrometry. Also, radiotracer experiments using soils under aerobic and anaerobic conditions were carried out to clarify the Tc behavior under paddy field conditions. The results of determination of global fallout 99 Tc in Japanese soils indicated that the radionuclide had been accumulating in rice paddy fields. The mechanisms can be explained by the immobilization of Tc in soil under anaerobic conditions. From the radiotracer experiments, it was clear that under waterlogged conditions, the highly mobile TcO 4 - in soil was readily changed to other immobilized forms, such as TcO 2 , TcS 2 and organically bound forms. To this immobilization, the microbial activity seemed to have an important role in Tc sorption reactions. When the soil, which was once kept in anaerobic conditions, was air-dried again and kept in aerobic conditions, the chemical forms of immobilized Tc did not change remarkably. Interestingly, the similar Tc behavior was observed in a real wet forest near the Chernobyl Reactor. (author)
Influence of the terrestrial magnetic field geometry on the cutoff rigidity of cosmic ray particles
International Nuclear Information System (INIS)
Herbst, K.; Kopp, A.; Heber, B.
2013-01-01
Studies of the propagation of charged energetic particles in the Earth's magnetic field go back to Carl Stoermer. In the end, his investigations finally lead to the definition of the so-called cutoff rigidity RC; that is, the minimum momentum per charge a particle must have in order to reach a certain geographical location. Employing Monte Carlo simulations with the PLANETOCOSMICS code we investigate the correlation between the geomagnetic field structure and the cutoff rigidity. We show that the geometry of the magnetic field has a considerable influence on the resulting cutoff rigidity distribution. Furthermore, we will present a simple geometry-based parameter, δB, which is able to reflect the location-dependent cutoff rigidity. We show that this correlation is also visible in the temporal evolution of the Earth's magnetic field, at least over the last 100 yr. Using latitude scans with neutron monitors, changes of the relative counting rates at different positions are calculated, showing small variations for, e.g., Kiel and Moscow, while large ones occur at Mexico City as well as on the British Virgin Islands.
International Nuclear Information System (INIS)
Zhang, Lijun; Stratmann, Matthias; Du, Yong; Sundman, Bo; Steinbach, Ingo
2015-01-01
A new approach to incorporate the sublattice models in the CALPHAD (CALculation of PHAse Diagram) formalism directly into the phase-field formalism is developed. In binary alloys, the sublattice models can be classified into two types (i.e., “Type I” and “Type II”), depending on whether a direct one-to-one relation between the element site fraction in the CALPHAD database and the phase concentration in the phase-field model exists (Type I), or not (Type II). For “Type II” sublattice models, the specific site fractions, corresponding to a given mole fraction, have to be established via internal relaxation between different sublattices. Internal minimization of sublattice occupancy and solute evolution during microstructure transformation leads, in general, to a solution superior to the separate solution of the individual problems. The present coupling technique is validated for Fe–C and Ni–Al alloys. Finally, the model is extended into multicomponent alloys and applied to simulate the nucleation process of VC monocarbide from austenite matrix in a steel containing vanadium
Directory of Open Access Journals (Sweden)
Mahmoud Bayat
Full Text Available The behavior of braced steel frame structures is of special importance due to its extensive use. Also the application of active and semi-active control systems, regarding to their benefits in obtaining better seismic performance has increased significantly. The majority of the works on steel structures and steel connections has been done under far field records, and the behavior of steel frame structures equipped with yielding dampers under these circumstances has not yet been fully analyzed. The main purpose of this paper is to determine the behavior of structures equipped with yielding dampers, located in near field based on energy concepts. In order to optimize their seismic behavior, the codes and solutions are also presented.The selected system is a braced steel frame system which is equipped with yielding dampers and the analysis is performed using the "Perform 3D V.4" software and the conclusions are drawn upon energy criterion. The effect of PGA variation and height of the frames are also considered in the study .Finally, using the above mentioned results, a proper solution is presented for typical systems in order to increase the energy damping ability and reduce the destructive effects in structures on an earthquake event, so that a great amount of induced energy is damped and destruction of the structure is prevented as much as possible.
Zero temperature dissipation and holography
Energy Technology Data Exchange (ETDEWEB)
Banerjee, Pinaki; Sathiapalan, B. [Institute of Mathematical Sciences,CIT Campus, Taramani, Chennai 600 113 (India)
2016-04-14
We use holographic techniques to study the zero-temperature limit of dissipation for a Brownian particle moving in a strongly coupled CFT at finite temperature in various space-time dimensions. The dissipative term in the boundary theory for ω→0, T→0 with ω/T held small and fixed, does not match the same at T=0, ω→0. Thus the T→0 limit is not smooth for ω
Bumble Bees (Bombus terrestris use mechanosensory hairs to detect electric fields
Directory of Open Access Journals (Sweden)
Sutton Gregory
2016-01-01
Full Text Available Bees and flowers have an intricate relationship which benefits both organisms. Plants provide nectar bees, in turn, distribute pollen to fertilize plants. To make pollination work, flowers need a mechanism to incentivize individual bees to visit only a single species of flower. Flowers, like modern advertising agencies, use multiple senses to create a floral ‘brand’ that is easily recognized. Size, smell, colour, touch, and even temperature are used to allow bees to differentiate between flower species. Recently, a new sense has been found that is usable by bees to differentiate flowers, an ‘electric sense’: they can identify flowers based only on the flower’s electric field. This new sense provides a novel example of how flowers differentiate themselves to bees and has obvious implications for how bees and flowers interact with the electrical world around us. Bumble bees detect this electric field by using their body hairs, which bend in the presence of electric charge.
Notari, Alessio
2016-12-22
We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term $\\frac{\\phi}{f_\\gamma} F \\tilde{F}$, such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density $\\rho_R$, which which can lead to inflation without the need of a flat potential. We analyze the system, for momenta $k$ smaller than the cutoff $f_\\gamma$, including numerically the backreaction. We consider the evolution from a given static initial condition and explicitly show that, if $f_\\gamma$ is smaller than the field excursion $\\phi_0$ by about a factor of at least ${\\cal O} (20)$, there is a friction effect which turns on before that the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of...
Knacker, T.; van Gestel, C.A.M.; Jones, S.E.; Soares, A.M.V.M.; Schallnass, H.-J.; Förster, B.; Edwards, C.A.
2004-01-01
During spring and summer 1999 a ring-test and field-validation study with an open, intact Terrestrial Model Ecosystem (TME) was conducted at four different European sites (Amsterdam, The Netherlands; Bangor, U.K.; Coimbra, Portugal; Flörsheim, Germany). The objective of the study was to establish a
Moser, T.; van Gestel, C.A.M.; Jones, S.E.; Koolhaas, J.E.; Rodrigues, J.M.L.; Römbke, J.
2004-01-01
The effects of the fungicide carbendazim (applied in the formulation Derosal®) on enchytraeids were determined in Terrestrial Model Ecosystem (TME) tests and field-validation studies. TMEs consisted of intact soil columns (diameter 17.5 cm; length 40 cm) taken from a grassland or, in one case, from
van Gestel, C.A.M.; Koolhaas, J.E.; Schallnass, H.-J.; Rodrigues, J.M.L.; Jones, S.E.
2004-01-01
The effect of the fungicide carbendazim (applied in the formulation Derosal®) on nutrient cycling in soil was determined in Terrestrial Model Ecosystem (TME) tests and corresponding field-validation studies, which were performed in four different countries (United Kingdom, Germany, Portugal, and The
Koolhaas, J.E.; van Gestel, C.A.M.; Römbke, J.; Soares, A.M.V.M.; Jones, S.E.
2004-01-01
The effects of the fungicide carbendazim (applied in the formulation Derosal) on soil microarthropod communities was determined in three Terrestrial Model Ecosystem (TME) tests and a field-validation study for a period of 16 weeks after application. TMEs consisted of intact soil columns (diameter
Moser, T.; Schallnass, H.-J.; Jones, S.E.; van Gestel, C.A.M.; Koolhaas, J.E.; Rodrigues, J.M.L.; Römbke, J.
2004-01-01
The effects of the fungicide carbendazim (applied in the formulation Derosal®) on nematodes was determined in Terrestrial Model Ecosystem (TME) tests and field-validation studies. TMEs consisted of intact soil columns (diameter 17.5 cm; length 40 cm) taken from a grassland or, in one case, from an
Shocklets, SLAMS, and Field-Aligned Ion Beams in the Terrestrial Foreshock
Wilson, L. B.; Koval, A.; Sibeck, D. G.; Szabo, A.; Cattell, C. A.; Kasper, J. C.; Maruca, B. A.; Pulupa, M.; Salem, C. S.; Wilber, M.
2012-01-01
We present Wind spacecraft observations of ion distributions showing field- aligned beams (FABs) and large-amplitude magnetic fluctuations composed of a series of shocklets and short large-amplitude magnetic structures (SLAMS). The FABs are found to have T(sub k) approx 80-850 eV, V(sub b)/V(sub sw) approx 1.3-2.4, T(sub perpendicular,b)/T(sub paralell,b) approx 1-8, and n(sub b)/n(sub o) approx 0.2-11%. Saturation amplitudes for ion/ion resonant and non-resonant instabilities are too small to explain the observed SLAMS amplitudes. We show two examples where groups of SLAMS can act like a local quasi-perpendicular shock reflecting ions to produce the FABs, a scenario distinct from the more-common production at the quasi-perpendicular bow shock. The SLAMS exhibit a foot-like magnetic enhancement with a leading magnetosonic whistler train, consistent with previous observations. Strong ion and electron heating are observed within the series of shocklets and SLAMS with temperatures increasing by factors approx > 5 and approx >3, respectively. Both the core and halo electron components show strong perpendicular heating inside the feature.
PNAS Plus: Origin of first cells at terrestrial, anoxic geothermal fields
Mulkidjanian, Armen Y.; Bychkov, Andrew Yu.; Dibrova, Daria V.; Galperin, Michael Y.; Koonin, Eugene V.
2012-04-01
All cells contain much more potassium, phosphate, and transition metals than modern (or reconstructed primeval) oceans, lakes, or rivers. Cells maintain ion gradients by using sophisticated, energy-dependent membrane enzymes (membrane pumps) that are embedded in elaborate ion-tight membranes. The first cells could possess neither ion-tight membranes nor membrane pumps, so the concentrations of small inorganic molecules and ions within protocells and in their environment would equilibrate. Hence, the ion composition of modern cells might reflect the inorganic ion composition of the habitats of protocells. We attempted to reconstruct the "hatcheries" of the first cells by combining geochemical analysis with phylogenomic scrutiny of the inorganic ion requirements of universal components of modern cells. These ubiquitous, and by inference primordial, proteins and functional systems show affinity to and functional requirement for K+, Zn2+, Mn2+, and phosphate. Thus, protocells must have evolved in habitats with a high K+/Na+ ratio and relatively high concentrations of Zn, Mn, and phosphorous compounds. Geochemical reconstruction shows that the ionic composition conducive to the origin of cells could not have existed in marine settings but is compatible with emissions of vapor-dominated zones of inland geothermal systems. Under the anoxic, CO2-dominated primordial atmosphere, the chemistry of basins at geothermal fields would resemble the internal milieu of modern cells. The precellular stages of evolution might have transpired in shallow ponds of condensed and cooled geothermal vapor that were lined with porous silicate minerals mixed with metal sulfides and enriched in K+, Zn2+, and phosphorous compounds.
Microscopic nuclear dissipation. Pt. 2
International Nuclear Information System (INIS)
Yannouleas, C.; Dworzecka, M.; Griffin, J.J.
1983-01-01
We have formulated a microscopic, nonperturbative, time reversible model which exhibits a dissipative decay of collective motion for times short compared to the system's Poincare time. The model assumes an RPA approximate description of the initial collective state within a restricted subspace, then traces its time evolution when an additional subspace is coupled to the restricted subspace by certain simplified matrix elements. It invokes no statistical assumptions. The damping of the collective motion occurs via real transitions from the collective state to other more complicated nuclear states of the same energy. It corresponds therefore to the so called 'one-body' long mean free path limit of nuclear dissipation when the collective state describes a surface vibration. When the simplest RPA approximation is used, this process associates the dissipation with the escape width for direct particle emission to the continuum. When the more detailed second RPA is used, it associates the dissipation with the spreading width for transitions to the 2p-2h components of the nuclear compound states as well. The energy loss rate for sharp n-phonon initial states is proportional to the total collective energy, unlike the dissipation of a classical damped oscillator, where it is proportional to the kinetic energy only. However, for coherent, multi-phonon wave packets, which explicitly describe the time-dependent oscillations of the mean field, dissipation proportional only to the kinetic energy is obtained. Canonical coordinates for the collective degree of freedom are explicitly introduced and a nonlinear frictional hamiltonian to describe such systems is specified by the requirement that it yield the same time dependence for the collective motion as the microscopic model. Thus, for the first time a descriptive nonlinear hamiltonian is derived explicitly from the underlying microscopic model of a nuclear system. (orig.)
Laycock, Ian; Cotterell, Katie C; O'Shea-Wheller, Thomas A; Cresswell, James E
2014-02-01
Neonicotinoid pesticides are currently implicated in the decline of wild bee populations. Bumble bees, Bombus spp., are important wild pollinators that are detrimentally affected by ingestion of neonicotinoid residues. To date, imidacloprid has been the major focus of study into the effects of neonicotinoids on bumble bee health, but wild populations are increasingly exposed to alternative neonicotinoids such as thiamethoxam. To investigate whether environmentally realistic levels of thiamethoxam affect bumble bee performance over a realistic exposure period, we exposed queenless microcolonies of Bombus terrestris L. workers to a wide range of dosages up to 98 μgkg(-1) in dietary syrup for 17 days. Results showed that bumble bee workers survived fewer days when presented with syrup dosed at 98 μg thiamethoxamkg(-1), while production of brood (eggs and larvae) and consumption of syrup and pollen in microcolonies were significantly reduced by thiamethoxam only at the two highest concentrations (39, 98 μgkg(-1)). In contrast, we found no detectable effect of thiamethoxam at levels typically found in the nectars of treated crops (between 1 and 11 μgkg(-1)). By comparison with published data, we demonstrate that during an exposure to field-realistic concentrations lasting approximately two weeks, brood production in worker bumble bees is more sensitive to imidacloprid than thiamethoxam. We speculate that differential sensitivity arises because imidacloprid produces a stronger repression of feeding in bumble bees than thiamethoxam, which imposes a greater nutrient limitation on production of brood. © 2013 Published by Elsevier Inc.
Dissipative fluid mechanics of nuclei
International Nuclear Information System (INIS)
Morgenstern, B.
1987-11-01
With the aim to describe nucleus-nucleus collisions at low energies in the present thesis for the first time dissipative fluid dynamics for large-amplitude nuclear motion have been formulated. Thereby the collective dynamics are described in a scaling approximation in which the wave function of the system is distorted by a vortex-free velocity field. For infintely extended nuclear matter this scaling of the wave functions leads to a deformation of the Fermi sphere. Two-body collisions destroy the collective deformation of the Fermi sphere and yield so the dissipative contribution of the motion. Equations of motion for a finite set of collective variables and a field equation for the collective velocity potential in the limit of infinitely many degrees of freedom were developed. In the elastic limit oscillations around the equilibrium position are described. For small collective amplitudes and vortex-free velocity fields the integrodifferential equation for the velocity potential in the elastic limit could be transformed to the divergence of the field equation of fluid dynamics. In the dissipative limit an equation results which is similar to the Navier-Stokes equation and transforms to the divergence of the Navier-Stokes equation for vortex-free fields. It was shown that generally the dynamics of the many-body system is described by non-Markovian equations. (orig./HSI) [de
Effects of dissipation and fluctuation in preheating
International Nuclear Information System (INIS)
Vartuli, Rodrigo; Ramos, Rudnei de O.
2006-01-01
In this paper, we study the effects of dissipation and fluctuation in preheating after inflation. The effective equation of motion for a scalar field χ interacting with lighter fields is derived using the field theoretical method of closed time path due to Schwinger, winch is suitable to study nonequilibrium and time dependent process. In this derivation the emergent equation is intrinsically dissipative and stochastic in nature. The resulting dynamics is then studied both analytically and numerically. The results obtained are then discussed for then relevance for the reheating epoch right after an inflationary phase(preheating) for the case of the evolution of the scalar field χ and its decay into fermion. (author)
Spatial Inhomogeneity of Kinetic and Magnetic Dissipations in Thermal Convection
Energy Technology Data Exchange (ETDEWEB)
Hotta, H. [Department of Physics, Graduate School of Science, Chiba university, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522 (Japan)
2017-08-20
We investigate the inhomogeneity of kinetic and magnetic dissipations in thermal convection using high-resolution calculations. In statistically steady turbulence, the injected and dissipated energies are balanced. This means that a large amount of energy is continuously converted into internal energy via dissipation. As in thermal convection, downflows are colder than upflows and the inhomogeneity of the dissipation potentially changes the convection structure. Our investigation of the inhomogeneity of the dissipation shows the following. (1) More dissipation is seen around the bottom of the calculation domain, and this tendency is promoted with the magnetic field. (2) The dissipation in the downflow is much larger than that in the upflow. The dissipation in the downflow is more than 80% of the total at maximum. This tendency is also promoted with the magnetic field. (3) Although 2D probability density functions of the kinetic and magnetic dissipations versus the vertical velocity are similar, the kinetic and magnetic dissipations are not well correlated. Our result suggests that the spatial inhomogeneity of the dissipation is significant and should be considered when modeling a small-scale strong magnetic field generated with an efficient small-scale dynamo for low-resolution calculations.
Energy Technology Data Exchange (ETDEWEB)
Notari, Alessio [Departament de Física Fondamental i Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, Barcelona, 08028 Spain (Spain); Tywoniuk, Konrad, E-mail: notari@ffn.ub.es, E-mail: konrad.tywoniuk@cern.ch [Theoretical Physics Department, CERN, Geneva (Switzerland)
2016-12-01
We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term φ/ f {sub γ} F ∼ F , such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density ρ{sub R}, which can lead to inflation without the need of a flat potential. We analyze the system, for momenta k smaller than the cutoff f {sub γ}, including the backreaction numerically. We consider the evolution from a given static initial condition and explicitly show that, if f {sub γ} is smaller than the field excursion φ{sub 0} by about a factor of at least O (20), there is a friction effect which turns on before the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of perturbations, scalars and tensors. Such oscillations have a period of 4–5 efolds and an amplitude which is typically less than a few percent and decreases linearly with f {sub γ}. We also stress that the curvature perturbation on uniform density slices should be sensitive to slow-roll parameters related to ρ{sub R} rather than φ-dot {sup 2}/2 and we discuss the existence of friction terms acting on the perturbations, although we postpone a calculation of the power spectrum and of non-gaussianity to future work and we simply define and compute suitable slow roll parameters. Finally we stress that this scenario may be realized in the axion case, if the coupling 1/ f {sub γ} to U(1) (photons) is much larger than the coupling 1/ f {sub G} to non-abelian gauge fields (gluons), since the latter sets the range of the potential and therefore the maximal allowed φ{sub 0∼} f {sub G}.
Dissipative relativistic hydrodynamics
International Nuclear Information System (INIS)
Imshennik, V.S.; Morozov, Yu.I.
1989-01-01
Using the comoving reference frame in the general non-inertial case, the relativistic hydrodynamics equations are derived with an account for dissipative effects in the matter. From the entropy production equation, the exact from for the dissipative tensor components is obtained. As a result, the closed system of equations of dissipative relativistic hydrodynamics is obtained in the comoving reference frame as a relativistic generalization of the known Navier-Stokes equations for Lagrange coordinates. Equations of relativistic hydrodynamics with account for dissipative effects in the matter are derived using the assocoated reference system in general non-inertial case. True form of the dissipative tensor components is obtained from entropy production equation. Closed system of equations for dissipative relativistic hydrodynamics is obtained as a result in the assocoated reference system (ARS) - relativistic generalization of well-known Navier-Stokes equations for Lagrange coordinates. Equation system, obtained in this paper for ARS, may be effectively used in numerical models of explosive processes with 10 51 erg energy releases which are characteristic for flashes of supernovae, if white dwarf type compact target suggested as presupernova
Energy dissipation mapping of cancer cells.
Dutta, Diganta; Palmer, Xavier-Lewis; Kim, Jinhyun; Qian, Shizhi; Stacey, Michael
2018-02-01
The purpose of this study is to map the energy dissipation of Jurkat cells using a single 60 nanosecond pulse electric field (NsPEF), primarily through atomic force microscopy (AFM). The phase shift is generated by the sample elements that do not have a heterogeneous surface. Monitoring and manipulating the phase shift is a powerful way for determining the dissipated energy and plotting the topography. The dissipated energy is a relative value, so the silica wafer and cover slip are given a set reference while the transmission of energy between the tip of the cantilever and cell surfaces is measured. The most important finding is that the magnitude and the number of variations in the dissipated energy change with the strength of NsPEF applied. Utilizing a single low field strength NsPEF (15kV/cm), minor changes in dissipated energy were found. The application of a single high field strength NsPEF (60kV/cm) to Jurkat cells resulted in a higher dissipated energy change versus that of in the low field strength condition. Thus, the dissipated energy from the Jurkat cells changes with the strength of NsPEF. By analyzing the forces via investigation in the tapping mode of the AFM, the stabilization of the cytoskeleton and membrane of the cell are related to the strength of NsPEF applied. Furthermore, the strength of NsPEF indicates a meaningful relationship to the survival of the Jurkat cells. Copyright © 2017 Elsevier Ltd. All rights reserved.
Graphene heat dissipating structure
Washburn, Cody M.; Lambert, Timothy N.; Wheeler, David R.; Rodenbeck, Christopher T.; Railkar, Tarak A.
2017-08-01
Various technologies presented herein relate to forming one or more heat dissipating structures (e.g., heat spreaders and/or heat sinks) on a substrate, wherein the substrate forms part of an electronic component. The heat dissipating structures are formed from graphene, with advantage being taken of the high thermal conductivity of graphene. The graphene (e.g., in flake form) is attached to a diazonium molecule, and further, the diazonium molecule is utilized to attach the graphene to material forming the substrate. A surface of the substrate is treated to comprise oxide-containing regions and also oxide-free regions having underlying silicon exposed. The diazonium molecule attaches to the oxide-free regions, wherein the diazonium molecule bonds (e.g., covalently) to the exposed silicon. Attachment of the diazonium plus graphene molecule is optionally repeated to enable formation of a heat dissipating structure of a required height.
Do, F; Rocheteau, A
2002-06-01
The thermal dissipation method is simple and widely used for measuring sap flow in large stems. As with several other thermal methods, natural temperature gradients are assumed to be negligible in the sapwood being measured. We studied the magnitude and variability of natural temperature gradients in sapwood of Acacia trees growing in the Sahelian zone of Senegal, analyzed their effects on sap flow measurements, and investigated possible solutions. A new measurement approach employing cyclic heating (45 minutes of heating and 15 minutes of cooling; 45/15) was also tested. Three-day measurement sequences that included 1 day without heating, a second day with continuous heating and a third day with cyclic heating were recorded during a 6.5-month period using probes installed at three azimuths in a tree trunk. Natural temperature gradients between the two probes of the sensor unit, spaced 8 to 10 cm vertically, were rarely negligible (i.e., solar radiation and low sap flow rate. However, for all applications of the thermal dissipation method, it is wise to check regularly for natural temperature gradients by switching off the heater.
Analysing half-lives for pesticide dissipation in plants
DEFF Research Database (Denmark)
Jacobsen, R.E.; Fantke, Peter; Trapp, Stefan
2015-01-01
Overall dissipation of pesticides from plants is frequently measured, but the contribution of individual loss processes is largely unknown. We use a pesticide fate model for the quantification of dissipation by processes other than degradation. The model was parameterised using field studies....... Scenarios were established for Copenhagen/Denmark and Shanghai/PR China, and calibrated with measured results. The simulated dissipation rates of 42 pesticides were then compared with measured overall dissipation from field studies using tomato and wheat. The difference between measured overall dissipation...... and scenario. Accordingly, degradation is the most relevant dissipation process for these 42 pesticides, followed by growth dilution. Volatilisation was less relevant, which can be explained by the design of plant protection agents. Uptake of active compound from soil into plants leads to a negative...
Wave-Number Spectra and Intermittency in the Terrestrial Foreshock Region
International Nuclear Information System (INIS)
Narita, Y.; Glassmeier, K.-H.; Treumann, R. A.
2006-01-01
Wave-number spectra of magnetic field fluctuations are directly determined in the terrestrial foreshock region (upstream of a quasiparallel collisionless shock wave) using four-point Cluster spacecraft measurements. The spectral curve is characterized by three ranges reminiscent of turbulence: energy injection, inertial, and dissipation range. The spectral index for the inertial range spectrum is close to Kolmogorov's slope, -5/3. On the other hand, the fluctuations are highly anisotropic and intermittent perpendicular to the mean magnetic field direction. These results suggest that the foreshock is in a weakly turbulent and intermittent state in which parallel propagating Alfven waves interact with one another, resulting in the phase coherence or the intermittency
Farr, T. G.; Arcone, S.; Arvidson, R. W.; Baker, V.; Barlow, N. G.; Beaty, D.; Bell, M. S.; Blankenship, D. D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S. M.; Craddock, R. A.; Dickerson, P. W.; Duxbury, N.; Galford, G. L.; Garvin, J.; Grant, J.; Green, J. R.; Gregg, T. K. P.; Guinness, E.; Hansen, V. L.; Hecht, M. H.; Holt, J.; Howard, A.; Keszthelyi, L. P.; Lee, P.; Lanagan, P. D.; Lentz, R. C. F.; Leverington, D. W.; Marinangeli, L.; Moersch, J. E.; Morris-Smith, P. A.; Mouginis-Mark, P.; Olhoeft, G. R.; Ori, G. G.; Paillou, P.; Reilly, J. F., II; Rice, J. W., Jr.; Robinson, C. A.; Sheridan, M.; Snook, K.; Thomson, B. J.; Watson, K.; Williams, K.; Yoshikawa, K.
2002-08-01
It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of Martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the Mars Exploration Payload Assessment Group science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel has considered the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.
Collective variables and dissipation
International Nuclear Information System (INIS)
Balian, R.
1984-09-01
This is an introduction to some basic concepts of non-equilibrium statistical mechanics. We emphasize in particular the relevant entropy relative to a given set of collective variables, the meaning of the projection method in the Liouville space, its use to establish the generalized transport equations for these variables, and the interpretation of dissipation in the framework of information theory
Ogura-Tsujita, Yuki; Hirayama, Yumiko; Sakoda, Aki; Suzuki, Ayako; Ebihara, Atsushi; Morita, Nana; Imaichi, Ryoko
2016-02-01
To determine the mycorrhizal status of pteridophyte gametophytes in diverse taxa, the mycorrhizal colonization of wild gametophytes was investigated in terrestrial cordate gametophytes of pre-polypod leptosporangiate ferns, i.e., one species of Osmundaceae (Osmunda banksiifolia), two species of Gleicheniaceae (Diplopterygium glaucum, Dicranopteris linearis), and four species of Cyatheales including tree ferns (Plagiogyriaceae: Plagiogyria japonica, Plagiogyria euphlebia; Cyatheaceae: Cyathea podophylla, Cyathea lepifera). Microscopic observations revealed that 58 to 97% of gametophytes in all species were colonized with arbuscular mycorrhizal (AM) fungi. Fungal colonization was limited to the multilayered midrib (cushion) tissue in all gametophytes examined. Molecular identification using fungal SSU rDNA sequences indicated that the AM fungi in gametophytes primarily belonged to the Glomeraceae, but also included the Claroideoglomeraceae, Gigasporaceae, Acaulosporaceae, and Archaeosporales. This study provides the first evidence for AM fungal colonization of wild gametophytes in the Plagiogyriaceae and Cyatheaceae. Taxonomically divergent photosynthetic gametophytes are similarly colonized by AM fungi, suggesting that mycorrhizal associations with AM fungi could widely occur in terrestrial pteridophyte gametophytes.
Dissipative hidden sector dark matter
Foot, R.; Vagnozzi, S.
2015-01-01
A simple way of explaining dark matter without modifying known Standard Model physics is to require the existence of a hidden (dark) sector, which interacts with the visible one predominantly via gravity. We consider a hidden sector containing two stable particles charged under an unbroken U (1 )' gauge symmetry, hence featuring dissipative interactions. The massless gauge field associated with this symmetry, the dark photon, can interact via kinetic mixing with the ordinary photon. In fact, such an interaction of strength ε ˜10-9 appears to be necessary in order to explain galactic structure. We calculate the effect of this new physics on big bang nucleosynthesis and its contribution to the relativistic energy density at hydrogen recombination. We then examine the process of dark recombination, during which neutral dark states are formed, which is important for large-scale structure formation. Galactic structure is considered next, focusing on spiral and irregular galaxies. For these galaxies we modeled the dark matter halo (at the current epoch) as a dissipative plasma of dark matter particles, where the energy lost due to dissipation is compensated by the energy produced from ordinary supernovae (the core-collapse energy is transferred to the hidden sector via kinetic mixing induced processes in the supernova core). We find that such a dynamical halo model can reproduce several observed features of disk galaxies, including the cored density profile and the Tully-Fisher relation. We also discuss how elliptical and dwarf spheroidal galaxies could fit into this picture. Finally, these analyses are combined to set bounds on the parameter space of our model, which can serve as a guideline for future experimental searches.
Magnetization dissipation in ferromagnets from scattering theory
Brataas, A.; Tserkovnyak, Y.; Bauer, G.E.W.
2011-01-01
The magnetization dynamics of ferromagnets is often formulated in terms of the Landau-Lifshitz-Gilbert (LLG) equation. The reactive part of this equation describes the response of the magnetization in terms of effective fields, whereas the dissipative part is parametrized by the Gilbert damping
Foucault Dissipation in a Rolling Cylinder: A Webcam Quantitative Study
Bonanno, A.; Bozzo, G.; Camarca, M.; Sapia, P.
2011-01-01
In this paper we present an experimental strategy to measure the micro power dissipation due to Foucault "eddy" currents in a copper cylinder rolling on two parallel conductive rails in the presence of a magnetic field. Foucault power dissipation is obtained from kinematical measurements carried out by using a common PC webcam and video analysis…
Dissipation and leaching of pyroxasulfone and s-metolachlor
Pyroxasulfone dissipation and mobility in the soil was evaluated and compared to S-metolachlor in 2009 and 2010 at two field sites in northern Colorado, on a Nunn fine clay loam, and Olney fine sandy loam soil. Pyroxasulfone dissipation half-life (DT50) values varied from 47 to 134 d, and those of S...
DISSIPATION PATTERN OF BIFENTHRIN IN TOMATO
Ravi Kumar Katroju; Sreenivasa Rao Cherukuri; Shashi Bushan Vemuri; Narasimha Reddy K
2014-01-01
Field experiment carried out during kharif, 2012 to evaluate the dissipation pattern of most commonly used insecticide bifenthrin 10 EC @ 100 g a.i. ha-1 with two sprays of insecticide first given after fruit initiation and the second spray 10 days later and collecting the fruits at 0, 1, 3, 5, 7, 10, 15, 20 days after last spray, and analysed for residues using the validated QuEChERS method. The initial deposits of bifenthrin were 0.85 mg kg-1 which dissipated to 0.39, 0.15 mg kg-1 by 1st an...
Complex Fluids in Energy Dissipating Systems
Directory of Open Access Journals (Sweden)
Francisco J. Galindo-Rosales
2016-07-01
Full Text Available The development of engineered systems for energy dissipation (or absorption during impacts or vibrations is an increasing need in our society, mainly for human protection applications, but also for ensuring the right performance of different sort of devices, facilities or installations. In the last decade, new energy dissipating composites based on the use of certain complex fluids have flourished, due to their non-linear relationship between stress and strain rate depending on the flow/field configuration. This manuscript intends to review the different approaches reported in the literature, analyses the fundamental physics behind them and assess their pros and cons from the perspective of their practical applications.
Dissipative phenomena in condensed matter some applications
Dattagupta, Sushanta
2004-01-01
From the field of nonequilibrium statistical physics, this graduate- and research-level volume treats the modeling and characterization of dissipative phenomena. A variety of examples from diverse disciplines like condensed matter physics, materials science, metallurgy, chemical physics etc. are discussed. Dattagupta employs the broad framework of stochastic processes and master equation techniques to obtain models for a wide range of experimentally relevant phenomena such as classical and quantum Brownian motion, spin dynamics, kinetics of phase ordering, relaxation in glasses, dissipative tunneling. It provides a pedagogical exposition of current research material and will be useful to experimentalists, computational physicists and theorists.
Theoretical Consolidation of Acoustic Dissipation
Casiano, M. J.; Zoladz, T. F.
2012-01-01
In many engineering problems, the effects of dissipation can be extremely important. Dissipation can be represented by several parameters depending on the context and the models that are used. Some examples of dissipation-related parameters are damping ratio, viscosity, resistance, absorption coefficients, pressure drop, or damping rate. This Technical Memorandum (TM) describes the theoretical consolidation of the classic absorption coefficients with several other dissipation parameters including linearized resistance. The primary goal of this TM is to theoretically consolidate the linearized resistance with the absorption coefficient. As a secondary goal, other dissipation relationships are presented.
Topological protection of multiparticle dissipative transport
Loehr, Johannes; Loenne, Michael; Ernst, Adrian; de Las Heras, Daniel; Fischer, Thomas M.
2016-06-01
Topological protection allows robust transport of localized phenomena such as quantum information, solitons and dislocations. The transport can be either dissipative or non-dissipative. Here, we experimentally demonstrate and theoretically explain the topologically protected dissipative motion of colloidal particles above a periodic hexagonal magnetic pattern. By driving the system with periodic modulation loops of an external and spatially homogeneous magnetic field, we achieve total control over the motion of diamagnetic and paramagnetic colloids. We can transport simultaneously and independently each type of colloid along any of the six crystallographic directions of the pattern via adiabatic or deterministic ratchet motion. Both types of motion are topologically protected. As an application, we implement an automatic topologically protected quality control of a chemical reaction between functionalized colloids. Our results are relevant to other systems with the same symmetry.
Magnetic energy dissipation in force-free jets
Choudhuri, Arnab Rai; Konigl, Arieh
1986-01-01
It is shown that a magnetic pressure-dominated, supersonic jet which expands or contracts in response to variations in the confining external pressure can dissipate magnetic energy through field-line reconnection as it relaxes to a minimum-energy configuration. In order for a continuous dissipation to occur, the effective reconnection time must be a fraction of the expansion time. The dissipation rate for the axisymmetric minimum-energy field configuration is analytically derived. The results indicate that the field relaxation process could be a viable mechanism for powering the synchrotron emission in extragalactic jets if the reconnection time is substantially shorter than the nominal resistive tearing time in the jet.
Landry, B. J.; Blair, D.; Causey, J.; Collins, J.; Davis, A.; Fernandez-Kim, V.; Kennedy, J.; Pate, N.; Kearney, C.; Schayer, C.; Turk, E.; Cherry, M. L.; Fava, C.; Granger, D.; Stewart, M.; Guzik, T. G.
2017-12-01
High energy gamma ray flashes from terrestrial sources have been observed by satellites for decades, but the actual mechanism, assumed to be thunderstorm lightning, has yet to be fully characterized. The goal of COTEL, funded by NASA through the University Student Instrument Project (USIP) program, is to correlate in time TGF events, lightning strikes, and electric fields inside of thunderstorms. This will be accomplished using a small network of balloon-borne payloads suspended in and around thunderstorm environments. The payloads will detect and timestamp gamma radiation bursts, lightning strikes, and the intensity of localized electric fields. While in flight, data collected by the payloads will be transmitted to a ground station in real-time and will be analyzed post-flight to investigate potential correlations between lightning, TGFs, and electric fields. The COTEL student team is in its second year of effort having spent the first year developing the basic balloon payloads and ground tracking system. Currently the team is focusing on prototype electric field and gamma radiation detectors. Testing and development of these systems will continue into 2018, and flight operations will take place during the spring 2018 Louisiana thunderstorm season. The presentation, led by undergraduate Physics student Brad Landry, will cover the student team effort in developing the COTEL system, an overview of the system architecture, balloon flight tests conducted to date, preliminary results from prototype detectors, lessons learned for student-led science projects, and future plans.
International Nuclear Information System (INIS)
Niciejewski, R.; Killeen, T.L.; Turnbull, M.
1994-01-01
The application of Fabry-Perot interferometers (FPIs) to the study of upper atmosphere thermodynamics has largely been restricted by the very low light levels in the terrestrial airglow as well as the limited range in wavelength of photomultiplier tube (PMT) technology. During the past decade, the development of the scientific grade charge-coupled device (CCD) has progressed to the stage in which the detector has become the logical replacement for the PMT. Small fast microcomputers have made it possible to ''upgrade'' the remote field sites which bare CCDs and not only retain the previous capabilities of the existing FPIs but expand the data coverage in both temporal and wavelength domains. The problems encountered and the solutions applied to the deployment of a bare CCD, with data acquisition and image reduction techniques, are discussed. Sample geophysical data determined from the FPI fringe profiles are shown for stations at Peach Mountain, Michigan, and Watson Lake, Yukon Territory
Ramasubramanian, T; Paramasivam, M; Nirmala, R
2016-06-01
A simple and sensitive analytical method has been developed and validated for the determination of trace amounts of imidacloprid in/on sugarcane sett, stalk and leaf. The method optimized in the present study requires less volume of organic solvent and time. Hence, this method is suitable for high-throughput analyses involving large number of samples. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.003 and 0.01 mg/kg, respectively. The recovery and relative standard deviation were more than 93 % and less than 4 %, respectively. Thus, it is obvious that the analytical method standardized in this study is more precise and accurate enough to determine the residues of imidacloprid in sugarcane sett, stalk and leaf. The dissipation and translocation of imidacloprid residues from treated cane setts to leaf and stalk were studied by adopting this method. In sugarcane setts, the residues of imidacloprid persisted up to 120 days with half-life of 15.4 days at its recommended dose (70 g a.i./ha). The residues of imidacloprid were found to be translocated from setts to stalk and leaf. The imidacloprid residues were detected up to 105 days in both leaf and stalk. Dipping of sugarcane setts in imidacloprid at its recommended dose may result in better protection of cane setts and established crop because of higher initial deposit (>100 mg/kg) and longer persistence (>120 days).
Energy Technology Data Exchange (ETDEWEB)
Gurevich, A.V. [P.N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow (Russian Federation)]. E-mail: alex@lpi.ru; Zybin, K.P. [P.N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow (Russian Federation); Medvedev, Yu.V. [Joint Institute for High Temperature, Russian Academy of Sciences, 127412 Moscow (Russian Federation)
2007-01-22
The new model of lightning step leader is proposed. It includes three main processes developing simultaneously in a strong electric field: conventional breakdown, effect of runaway electrons and runaway breakdown (RB). The theory of RB in strong electric field is developed. Comparison with the existing observational data shows that the model can serve as a background for the explanation of gamma bursts in step leader and TGF.
International Nuclear Information System (INIS)
Gurevich, A.V.; Zybin, K.P.; Medvedev, Yu.V.
2007-01-01
The new model of lightning step leader is proposed. It includes three main processes developing simultaneously in a strong electric field: conventional breakdown, effect of runaway electrons and runaway breakdown (RB). The theory of RB in strong electric field is developed. Comparison with the existing observational data shows that the model can serve as a background for the explanation of gamma bursts in step leader and TGF
Attractors of dissipative structure in three dissipative fluids
International Nuclear Information System (INIS)
Kondoh, Yoshiomi
1993-10-01
A general theory with use of auto-correlations for distributions is presented to derive that realization of coherent structures in general dissipative dynamic systems is equivalent to that of self-organized states with the minimum dissipation rate for instantaneously contained energy. Attractors of dissipative structure are shown to be given by eigenfunctions for dissipative dynamic operators of the dynamic system and to constitute the self-organized and self-similar decay phase. Three typical examples applied to incompressible viscous fluids, to incompressible viscous and resistive magnetohydrodynamic (MHD) fluids and to compressible resistive MHD plasmas are presented to lead to attractors in the three dissipative fluids and to describe a common physical picture of self-organization and bifurcation of the dissipative structure. (author)
DEFF Research Database (Denmark)
Liu, Wei; Nannarelli, Alberto
2008-01-01
A few classes of algorithms to implement division in hardware have been used over the years: division by digit-recurrence, by reciprocal approximation by iterative methods and by polynomial approximation. Due to the differences in the algorithms, a comparison among their implementation in terms o...... of performance and precision is sometimes hard to make. In this work, we use power dissipation and energy consumption as metrics to compare among those different classes of algorithms. There are no previous works in the literature presenting such a comparison....
Explicit dissipative structures
International Nuclear Information System (INIS)
Roessler, O.E.
1987-01-01
Dissipative structures consisting of a few macrovariables arise out of a sea of reversible microvariables. Unexpected residual effects of the massive underlying reversibility, on the macrolevel, cannot therefore be excluded. In the age of molecular-dynamics simulations, explicit dissipative structures like excitable systems (explicit observers) can be generated in a computer from first reversible principles. A class of classical, 1-D Hamiltonian systems of chaotic type is considered which has the asset that the trajectorial behavior in phase space can be understood geometrically. If, as nuatural, the number of particle types is much smaller than that of particles, the Gibbs symmetry must be taken into account. The permutation invariance drastically changes the behavior in phase space (quasi-periodization). The explicity observer becomes effectively reversible on a short time scale. In consequence, his ability to measure microscopic motions is suspended in a characteristic fashion. Unlike quantum mechanics whose holistic nature cannot be transcended, the present holistic (internal-interface) effects - mimicking the former to some extent - can be understood fully in principle
Topographic-driven instabilities in terrestrial bodies
Vantieghem, S.; Cebron, D.; Herreman, W.; Lacaze, L.
2013-12-01
Models of internal planetary fluid layers (core flows, subsurface oceans) commonly assume that these fluid envelopes have a spherical shape. This approximation however entails a serious restriction from the fluid dynamics point of view. Indeed, in the presence of mechanical forcings (precession, libration, nutation or tides) due to gravitational interaction with orbiting partners, boundary topography (e.g. of the core-mantle boundary) may excite flow instabilities and space-filling turbulence. These phenomena may affect heat transport and dissipation at the main order. Here, we focus on instabilities driven by longitudinal libration. Using a suite of theoretical tools and numerical simulations, we are able to discern a parameter range for which instability may be excited. We thereby consider deformations of different azimuthal order. This study gives the first numerical evidence of the tripolar instability. Furthermore, we explore the non-linear regime and investigate the amplitude as well as the dissipation of the saturated instability. Indeed, these two quantities control the torques on the solid layers and the thermal transport. Furthermore, based on this results, we address the issue of magnetic field generation associated with these flows (by induction or by dynamo process). This instability mechanism applies to both synchronized as non-synchronized bodies. As such, our results show that a tripolar instability might be present in various terrestrial bodies (Early Moon, Gallilean moons, asteroids, etc.), where it could participate in dynamo action. Simulation of a libration-driven tripolar instability in a deformed spherical fluid layer: snapshot of the velocity magnitude, where a complex 3D flow pattern is established.
2002-01-01
The moon's gravity imparts tremendous energy to the Earth, raising tides throughout the global oceans. What happens to all this energy? This question has been pondered by scientists for over 200 years, and has consequences ranging from the history of the moon to the mixing of the oceans. Richard Ray at NASA's Goddard Space Flight Center, Greenbelt, Md. and Gary Egbert of the College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Ore. studied six years of altimeter data from the TOPEX/Poseidon satellite to address this question. According to their report in the June 15 issue of Nature, about 1 terawatt, or 25 to 30 percent of the total tidal energy dissipation, occurs in the deep ocean. The remainder occurs in shallow seas, such as on the Patagonian Shelf. 'By measuring sea level with the TOPEX/Poseidon satellite altimeter, our knowledge of the tides in the global ocean has been remarkably improved,' said Richard Ray, a geophysicist at Goddard. The accuracies are now so high that this data can be used to map empirically the tidal energy dissipation. (Red areas, above) The deep-water tidal dissipation occurs generally near rugged bottom topography (seamounts and mid-ocean ridges). 'The observed pattern of deep-ocean dissipation is consistent with topographic scattering of tidal energy into internal motions within the water column, resulting in localized turbulence and mixing', said Gary Egbert an associate professor at OSU. One important implication of this finding concerns the possible energy sources needed to maintain the ocean's large-scale 'conveyor-belt' circulation and to mix upper ocean heat into the abyssal depths. It is thought that 2 terawatts are required for this process. The winds supply about 1 terawatt, and there has been speculation that the tides, by pumping energy into vertical water motions, supply the remainder. However, all current general circulation models of the oceans ignore the tides. 'It is possible that properly
Hacker, D. B.; Biek, R. F.; Rowley, P. D.
2015-12-01
The newly discovered Miocene Markagunt gravity slide (MGS; Utah, USA) represents the largest volcanic landslide structure on Earth. Recent geologic mapping of the MGS indicates that it was a large contiguous volcanic sheet of allochthonous andesitic mudflow breccias and lava flows, volcaniclastic rocks, and intertonguing regional ash-flow tuffs that blanketed an area of at least 5000 km2 with an estimated volume of ~3000 km3. From its breakaway zone in the Tushar and Mineral Mountains to its southern limits, the MGS is over 95 km long and at least 65 km wide. The MGS consists of four distinct structural segments: 1) a high-angle breakaway segment, 2) a bedding-plane segment, ~60 km long and ~65 km wide, typically located within the volcaniclastic Eocene-Oligocene Brian Head Formation, 3) a ramp segment ~1-2 km wide where the slide cuts upsection, and 4) a former land surface segment where the upper-plate moved at least 35 km over the Miocene landscape. The presence of basal and lateral cataclastic breccias, clastic dikes, jigsaw puzzle fracturing, internal shears, pseudotachylytes, and the overall geometry of the MGS show that it represents a single catastrophic emplacement event. The MGS represents gravitationally induced collapse of the southwest sector of the Oligocene to Miocene Marysvale volcanic field. We suggest that continuous growth of the Marysvale volcanic field, loading more volcanic rocks on a structurally weak Brian Head basement, created conditions necessary for gravity sliding. In addition, inflation of the volcanic pile due to multiple magmatic intrusions tilted the strata gently southward, inducing lateral spreading of the sub-volcanic rocks prior to failure. Although similar smaller-scale failures have been recognized from individual volcanoes, the MGS represents a new class of low frequency but high impact hazards associated with catastrophic sector collapse of large volcanic fields containing multiple volcanoes. The relationship of the MGS to
Energy dissipation in a finite volume of magnetic fluid
Energy Technology Data Exchange (ETDEWEB)
Bashtovoi, V.; Motsar, A.; Reks, A., E-mail: alexfx20@yandex.ru
2017-06-01
This study is devoted to investigation of energy dissipation processes which happen in a magnetic fluid drop with compound magnet during its motion in cylindrical non magnetic container. The possibility of energy dissipation control by means of electromagnetic field is examined. It's found that a change of magnetic field of compound magnet can lead to both increase and decrease of oscillation decay time and relative damping factor can be varied in a range of ±35%.
Conservation laws shape dissipation
Rao, Riccardo; Esposito, Massimiliano
2018-02-01
Starting from the most general formulation of stochastic thermodynamics—i.e. a thermodynamically consistent nonautonomous stochastic dynamics describing systems in contact with several reservoirs—we define a procedure to identify the conservative and the minimal set of nonconservative contributions in the entropy production. The former is expressed as the difference between changes caused by time-dependent drivings and a generalized potential difference. The latter is a sum over the minimal set of flux-force contributions controlling the dissipative flows across the system. When the system is initially prepared at equilibrium (e.g. by turning off drivings and forces), a finite-time detailed fluctuation theorem holds for the different contributions. Our approach relies on identifying the complete set of conserved quantities and can be viewed as the extension of the theory of generalized Gibbs ensembles to nonequilibrium situations.
International Nuclear Information System (INIS)
Aboufirassi, M; Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Meslin, C.; Metivier, V.; Nakagawa, T.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Wieloch, A.; Yuasa-Nakagawa, K.
1998-01-01
The binary character of the heavy ion collisions at intermediate energies in the exit channel has been observed under 30 MeV/n in medium and heavy systems. Measurements in light systems at energies approaching ∼ 100 MeV/nucleon as well as in very heavy systems have allowed to extend considerably the investigations of this binary process. Thus, the study of the Pb + Au system showed that the complete charge events indicated two distinct sources: the quasi-projectile and the quasi-target. The characteristics of these two sources are rather well reproduced by a trajectory computation which takes into account the Coulomb and nuclear forces and the friction appearing from the projectile-target interaction. The Wilczynski diagram is used to probe the correlation between the kinetic energy quenching and the deflecting angle. In case of the system Pb + Au at 29 MeV/nucleon the diagram indicate dissipative binary collisions typical for low energies. This binary aspect was also detected in the systems Xe + Ag at 44 MeV/nucleon, 36 Ar + 27 Al and 64 Zn + nat Ti. Thus, it was possible to reconstruct the quasi-projectile and to study its mass and excitation energy evolution as a function of the impact parameter. The dissipative binary collisions represent for the systems and energies under considerations the main contribution to the cross section. This does not implies that there are not other processes; particularly, the more or less complete fusion is also observed but with a low cross section which decreases with the increase of bombardment energy. More exclusive measurements with the INDRA detector on quasi-symmetric systems as Ar + KCl and Xe + Sn seem to confirm the importance of the binary collisions. The two source reconstruction of the Xe + Sn data at 50 MeV/nucleon reproduces the same behaviour as that observed in the system Pb + Au at 29 MeV/nucleon
Heterogeneous dissipative composite structures
Ryabov, Victor; Yartsev, Boris; Parshina, Ludmila
2018-05-01
The paper suggests mathematical models of decaying vibrations in layered anisotropic plates and orthotropic rods based on Hamilton variation principle, first-order shear deformation laminated plate theory (FSDT), as well as on the viscous-elastic correspondence principle of the linear viscoelasticity theory. In the description of the physical relationships between the materials of the layers forming stiff polymeric composites, the effect of vibration frequency and ambient temperature is assumed as negligible, whereas for the viscous-elastic polymer layer, temperature-frequency relationship of elastic dissipation and stiffness properties is considered by means of the experimentally determined generalized curves. Mitigation of Hamilton functional makes it possible to describe decaying vibration of anisotropic structures by an algebraic problem of complex eigenvalues. The system of algebraic equation is generated through Ritz method using Legendre polynomials as coordinate functions. First, real solutions are found. To find complex natural frequencies of the system, the obtained real natural frequencies are taken as input values, and then, by means of the 3rd order iteration method, complex natural frequencies are calculated. The paper provides convergence estimates for the numerical procedures. Reliability of the obtained results is confirmed by a good correlation between analytical and experimental values of natural frequencies and loss factors in the lower vibration tones for the two series of unsupported orthotropic rods formed by stiff GRP and CRP layers and a viscoelastic polymer layer. Analysis of the numerical test data has shown the dissipation & stiffness properties of heterogeneous composite plates and rods to considerably depend on relative thickness of the viscoelastic polymer layer, orientation of stiff composite layers, vibration frequency and ambient temperature.
International Nuclear Information System (INIS)
Wang, Y.H.; Cui, C.G.; Zhang, Y.Z.; Li, S.L.; Li, J.; Li, L.
1991-01-01
A set of resistivity-temperature (R-T) curves measured under various applied fields in a high-T c Bi-Pb-Sr-Ca-Cu-O thin film which has a zero-resistance temperature T c0 of 110 K is reported. The remarkable broadening of the transition width is discussed under the flux-creep model, considering the very short coherence length of this oxide superconductor. The resistivity is thermally activated, which is consistent with the Arrhenius law with a magnetic field and orientation-dependent activation energy U 0 (H,Θ). The U 0 (H,Θ) has a very high value of 381.6 meV under a field of 0.1 T parallel to the c axis. The upper critical field H c2 determined from these R-T curves shows high values and the effect of flux creep to the H c2 (0) is examined by the irreversible behavior with the ''giant'' flux-creep model
Terrestrial Planet Formation from an Annulus -- Revisited
Deienno, Rogerio; Walsh, Kevin J.; Kretke, Katherine A.; Levison, Harold F.
2018-04-01
Numerous recent theories of terrestrial planet formation suggest that, in order to reproduce the observed large Earth to Mars mass ratio, planets formed from an annulus of material within 1 au. The success of these models typically rely on a Mars sized embryo being scattered outside 1 au (to ~1.5 au) and starving, while those remaining inside 1 au continue growing, forming Earth and Venus. In some models the scattering is instigated by the migration of giant planets, while in others an embryo-instability naturally occurs due to the dissipation of the gaseous solar nebula. While these models can typically succeed in reproducing the overall mass ratio among the planets, the final angular momentum deficit (AMD) of the present terrestrial planets in our Solar System, and their radial mass concentration (RMC), namely the position where Mars end up in the simulations, are not always well reproduced. Assuming that the gas nebula may not be entirely dissipated when such an embryo-instability happens, here, we study the effects that the time of such an instability can have on the final AMD and RMC. In addition, we also included energy dissipation within embryo-embryo collisions by assuming a given coefficient of restitution for collisions. Our results show that: i) dissipation within embryo-embryo collisions do not play any important role in the final terrestrial planetary system; ii) the final AMD decreases only when the number of final planets formed increases; iii) the RMC tends to always be lower than the present value no matter the number of final planets; and iv) depending on the time that the embryo-instability happen, if too early, with too much gas still present, a second instability will generally happen after the dissipation of the gas nebula.
Entanglement from dissipation and holographic interpretation
Energy Technology Data Exchange (ETDEWEB)
Cantcheff, M.B. [IFLP-CONICET CC 67, La Plata, Buenos Aires (Argentina); Gadelha, Alexandre L. [Universidade Federal da Bahia, Instituto de Fisica, Salvador, BA (Brazil); Marchioro, Dafni F.Z.; Nedel, Daniel Luiz [Universidade Federal da Integracao Latino-Americana, Instituto Latino-Americano de Ciencias da Vida e da Natureza, Foz do Iguacu, PR (Brazil)
2018-02-15
In this work we study a dissipative field theory where the dissipation process is manifestly related to dynamical entanglement and put it in the holographic context. Such endeavour is realized by further development of a canonical approach to study quantum dissipation, which consists of doubling the degrees of freedom of the original system by defining an auxiliary one. A time dependent entanglement entropy for the vacuum state is calculated and a geometrical interpretation of the auxiliary system and the entropy is given in the context of the AdS/CFT correspondence using the Ryu-Takayanagi formula. We show that the dissipative dynamics is controlled by the entanglement entropy and there are two distinct stages: in the early times the holographic interpretation requires some deviation from classical General Relativity; in the later times the quantum system is described as a wormhole, a solution of the Einstein's equations near to a maximally extended black hole with two asymptotically AdS boundaries. We focus our holographic analysis in this regime, and suggest a mechanism similar to teleportation protocol to exchange (quantum) information between the two CFTs on the boundaries (see Maldacena et al. in Fortschr Phys 65(5):1700034, arXiv:1704.05333 [hep-th], 2017). (orig.)
Entanglement from dissipation and holographic interpretation
Cantcheff, M. Botta; Gadelha, Alexandre L.; Marchioro, Dáfni F. Z.; Nedel, Daniel Luiz
2018-02-01
In this work we study a dissipative field theory where the dissipation process is manifestly related to dynamical entanglement and put it in the holographic context. Such endeavour is realized by further development of a canonical approach to study quantum dissipation, which consists of doubling the degrees of freedom of the original system by defining an auxiliary one. A time dependent entanglement entropy for the vacumm state is calculated and a geometrical interpretation of the auxiliary system and the entropy is given in the context of the AdS/CFT correspondence using the Ryu-Takayanagi formula. We show that the dissipative dynamics is controlled by the entanglement entropy and there are two distinct stages: in the early times the holographic interpretation requires some deviation from classical General Relativity; in the later times the quantum system is described as a wormhole, a solution of the Einstein's equations near to a maximally extended black hole with two asymptotically AdS boundaries. We focus our holographic analysis in this regime, and suggest a mechanism similar to teleportation protocol to exchange (quantum) information between the two CFTs on the boundaries (see Maldacena et al. in Fortschr Phys 65(5):1700034, arXiv:1704.05333 [hep-th], 2017).
DEFF Research Database (Denmark)
Damgaard, Christian; Strandberg, Beate; Dupont, Yoko
were assessed at the ecosystem level by measuring biodiversity and functional traits. We have obtained an increased understanding of the causal relationship between plant communities and the soil fauna at the ecosystem level and increased knowledge on how and by what mechanisms important drivers...... that are known to affect plant communities may affect pollination and the soil fauna. The combined use of plant trait and soil fauna trait data in a full-factorial field experiment of glyphosate and nitrogen has never been explored before. The focus on plant and soil fauna traits rather than species enabled...... nitrogen, generally, resulted in increasing total plant cover and biomass, especially of fast-growing and competitive species as grasses and a few herbs such as Tanacetum vulgare. Using plant traits we found that increase in nitrogen promoted an increase in the average specific leaf area (SLA) and canopy...
''Reduced'' magnetohydrodynamics and minimum dissipation rates
International Nuclear Information System (INIS)
Montgomery, D.
1992-01-01
It is demonstrated that all solutions of the equations of ''reduced'' magnetohydrodynamics approach a uniform-current, zero-flow state for long times, given a constant wall electric field, uniform scalar viscosity and resistivity, and uniform mass density. This state is the state of minimum energy dissipation rate for these boundary conditions. No steady-state turbulence is possible. The result contrasts sharply with results for full three-dimensional magnetohydrodynamics before the reduction occurs
International Nuclear Information System (INIS)
Anon.
1977-01-01
The main effort of the Terrestrial Ecology Division has been redirected to a comprehensive study of the Espiritu Santo Drainage Basin located in northeastern Puerto Rico. The general objective are to provide baseline ecological data for future environmental assessment studies at the local and regional levels, and to provide through an ecosystem approach data for the development of management alternatives for the wise utilization of energy, water, and land resources. The interrelationships among climate, vegetation, soils, and man, and their combined influence upon the hydrologic cycle will be described and evaluated. Environmental management involves planning and decision making, and both require an adequate data base. At present, little is known about the interworkings of a complete, integrated system such as a drainage basin. A literature survey of the main research areas confirmed that, although many individual ecologically oriented studies have been carried out in a tropical environment, few if any provide the data base required for environmental management. In view of rapidly changing socio-economic conditions and natural resources limitations, management urgently requires data from these systems: physical (climatological), biological, and cultural. This integrated drainage basin study has been designed to provide such data. The scope of this program covers the hydrologic cycle as it is affected by the interactions of the physical, biological, and cultural systems
Lyutyy, T. V.; Reva, V. V.
2018-05-01
Ferrofluid heating by an external alternating field is studied based on the rigid dipole model, where the magnetization of each particle in a fluid is supposed to be firmly fixed in the crystal lattice. Equations of motion, employing Newton's second law for rotational motion, the condition of rigid body rotation, and the assumption that the friction torque is proportional to angular velocity are used. This oversimplification permits us to expand the model easily: to take into account the thermal noise and interparticle interaction that allows us to estimate from unified positions the role of thermal activation and dipole interaction in the heating process. Our studies are conducted in three stages. The exact expressions for the average power loss of a single particle are obtained within the dynamical approximation. Then, in the stochastic case, the power loss of a single particle is estimated analytically using the Fokker-Planck equation and numerically using the effective Langevin equation. Finally, the power loss for the particle ensemble is obtained using the molecular dynamics method. Here, the local dipole fields are calculated approximately based on the Barnes-Hut algorithm. The revealed trends in the behavior of both a single particle and the particle ensemble suggest the way of choosing the conditions for obtaining the maximum heating efficiency. The competitiveness character of the interparticle interaction and thermal noise is investigated in detail. Two situations, when the thermal noise rectifies the power loss reduction caused by the interaction, are described. The first of them is related to the complete destruction of dense clusters at high noise intensity. The second one originates from the rare switching of the particles in clusters due to thermal activation, when the noise intensity is relatively weak. In this way, the constructive role of noise appears in the system.
Dissipation of magnetic energy during disruptive current termination
International Nuclear Information System (INIS)
Yamazaki, K.; Schmidt, G.L.
1983-09-01
The magnetic coupling during a disruption between the plasma and the various coil systems on the PDX tokamak has been modeled. Using measured coil currents, the model indicates that dissipation of magnetic energy in the plasma equal to 75 % of the energy stored in the poloidal field of the plasma current does occur and that coupling between the plasma and the coil systems can reduce such dissipation. In the case of PDX ohmic discharges, bolometric measurements of radiation and charge exchange, integrated over a disruption, account for 90 % of the calculated energy dissipation. (author)
Dissipative structures in magnetorotational turbulence
Ross, Johnathan; Latter, Henrik N.
2018-03-01
Via the process of accretion, magnetorotational turbulence removes energy from a disk's orbital motion and transforms it into heat. Turbulent heating is far from uniform and is usually concentrated in small regions of intense dissipation, characterised by abrupt magnetic reconnection and higher temperatures. These regions are of interest because they might generate non-thermal emission, in the form of flares and energetic particles, or thermally process solids in protoplanetary disks. Moreover, the nature of the dissipation bears on the fundamental dynamics of the magnetorotational instability (MRI) itself: local simulations indicate that the large-scale properties of the turbulence (e.g. saturation levels, the stress-pressure relationship) depend on the short dissipative scales. In this paper we undertake a numerical study of how the MRI dissipates and the small-scale dissipative structures it employs to do so. We use the Godunov code RAMSES and unstratified compressible shearing boxes. Our simulations reveal that dissipation is concentrated in ribbons of strong magnetic reconnection that are significantly elongated in azimuth, up to a scale height. Dissipative structures are hence meso-scale objects, and potentially provide a route by which large scales and small scales interact. We go on to show how these ribbons evolve over time — forming, merging, breaking apart, and disappearing. Finally, we reveal important couplings between the large-scale density waves generated by the MRI and the small-scale structures, which may illuminate the stress-pressure relationship in MRI turbulence.
Dissipation-driven quantum phase transitions in collective spin systems
International Nuclear Information System (INIS)
Morrison, S; Parkins, A S
2008-01-01
We consider two different collective spin systems subjected to strong dissipation-on the same scale as interaction strengths and external fields-and show that either continuous or discontinuous dissipative quantum phase transitions can occur as the dissipation strength is varied. First, we consider a well-known model of cooperative resonance fluorescence that can exhibit a second-order quantum phase transition, and analyse the entanglement properties near the critical point. Next, we examine a dissipative version of the Lipkin-Meshkov-Glick interacting collective spin model, where we find that either first- or second-order quantum phase transitions can occur, depending only on the ratio of the interaction and external field parameters. We give detailed results and interpretation for the steady-state entanglement in the vicinity of the critical point, where it reaches a maximum. For the first-order transition we find that the semiclassical steady states exhibit a region of bistability. (fast track communication)
Antonious, George F; Turley, Eric T; Abubakari, Mutari; Snyder, John C
2017-04-03
The persistence and fate of chlorpyrifos and its two metabolites, chlorpyrifos-oxon and the 3, 5, 6-trichloro-2-pyridinol (TCP) break-down product were investigated on kale and collard leaves under field conditions. A simultaneous extraction and quantification procedure was developed for chrorpyrifos and its two main metabolites. Residues of chlorpyrifos, chlorpyrifos oxon, and TCP were determined using a gas chromatograph (GC) equipped with an electron capture detector (GC/ECD). Chlorpyrifos metabolites were detectable up to 23 days following application. Residues were confirmed using a GC equipped with a mass selective detector (GC/MSD) in total ion mode. Initial residues of chlorpyrifos were greater on collard (14.5 µg g -1 ) than kale (8.2 µg g -1 ) corresponding to half-lives (T 1/2 ) values of 7.4 and 2.2 days, respectively. TCP, the hydrolysis product, was more persistent on collards with an estimated T 1/2 of 6.5 days compared to kale (T 1/2 of 1.9 days).
Quench dynamics of a disordered array of dissipative coupled cavities.
Creatore, C; Fazio, R; Keeling, J; Türeci, H E
2014-09-08
We investigate the mean-field dynamics of a system of interacting photons in an array of coupled cavities in the presence of dissipation and disorder. We follow the evolution of an initially prepared Fock state, and show how the interplay between dissipation and disorder affects the coherence properties of the cavity emission, and show that these properties can be used as signatures of the many-body phase of the whole array.
Dynamical properties of dissipative XYZ Heisenberg lattices
Rota, R.; Minganti, F.; Biella, A.; Ciuti, C.
2018-04-01
We study dynamical properties of dissipative XYZ Heisenberg lattices where anisotropic spin-spin coupling competes with local incoherent spin flip processes. In particular, we explore a region of the parameter space where dissipative magnetic phase transitions for the steady state have been recently predicted by mean-field theories and exact numerical methods. We investigate the asymptotic decay rate towards the steady state both in 1D (up to the thermodynamical limit) and in finite-size 2D lattices, showing that critical dynamics does not occur in 1D, but it can emerge in 2D. We also analyze the behavior of individual homodyne quantum trajectories, which reveal the nature of the transition.
Patterns and Interfaces in Dissipative Dynamics
Pismen, L.M
2006-01-01
Spontaneous pattern formation in nonlinear dissipative systems far from equilibrium is a paradigmatic case of emergent behaviour associated with complex systems. It is encountered in a great variety of settings, both in nature and technology, and has numerous applications ranging from nonlinear optics through solid and fluid mechanics, physical chemistry and chemical engineering to biology. Nature creates its variety of forms through spontaneous pattern formation and self-assembly, and this strategy is likely to be imitated by future biomorphic technologies. This book is a first-hand account by one of the leading players in this field, which gives in-depth descriptions of analytical methods elucidating the complex evolution of nonlinear dissipative systems, and brings the reader to the forefront of current research. The introductory chapter on the theory of dynamical systems is written with a view to applications of its powerful methods to spatial and spatio-temporal patterns. It is followed by two chapters t...
Energy balance for a dissipative quantum system
International Nuclear Information System (INIS)
Kumar, Jishad
2014-01-01
The role of random force in maintaining equilibrium in a dissipative quantum system is studied here. We compute the instantaneous power supplied by the fluctuating (random) force, which provides information about the work done by the random force on the quantum subsystem of interest. The quantum Langevin equation formalism is used here to verify that, at equilibrium, the work done by the fluctuating force balances the energy lost by the quantum subsystem to the heat bath. The quantum subsystem we choose to couple to the heat bath is the charged oscillator in a magnetic field. We perform the calculations using the Drude regularized spectral density of bath oscillators instead of using a strict ohmic spectral density that gives memoryless damping. We also discuss the energy balance for our dissipative quantum system and in this regard it is to be understood that the physical system is the charged magneto-oscillator coupled to the heat bath, not the uncoupled charged magneto-oscillator. (paper)
Mode-locking via dissipative Faraday instability.
Tarasov, Nikita; Perego, Auro M; Churkin, Dmitry V; Staliunas, Kestutis; Turitsyn, Sergei K
2016-08-09
Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin-Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system-spectrally dependent losses-achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin-Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering.
Tanaka, K.L.; Skinner, J.A.; Crumpler, L.S.; Dohm, J.M.
2009-01-01
We photogeologically mapped the SP Mountain region of the San Francisco Volcanic Field in northern Arizona, USA to evaluate and improve the fidelity of approaches used in geologic mapping of Mars. This test site, which was previously mapped in the field, is chiefly composed of Late Cenozoic cinder cones, lava flows, and alluvium perched on Permian limestone of the Kaibab Formation. Faulting and folding has deformed the older rocks and some of the volcanic materials, and fluvial erosion has carved drainage systems and deposited alluvium. These geologic materials and their formational and modificational histories are similar to those for regions of the Martian surface. We independently prepared four geologic maps using topographic and image data at resolutions that mimic those that are commonly used to map the geology of Mars (where consideration was included for the fact that Martian features such as lava flows are commonly much larger than their terrestrial counterparts). We primarily based our map units and stratigraphic relations on geomorphology, color contrasts, and cross-cutting relationships. Afterward, we compared our results with previously published field-based mapping results, including detailed analyses of the stratigraphy and of the spatial overlap and proximity of the field-based vs. remote-based (photogeologic) map units, contacts, and structures. Results of these analyses provide insights into how to optimize the photogeologic mapping of Mars (and, by extension, other remotely observed planetary surfaces). We recommend the following: (1) photogeologic mapping as an excellent approach to recovering the general geology of a region, along with examination of local, high-resolution datasets to gain insights into the complexity of the geology at outcrop scales; (2) delineating volcanic vents and lava-flow sequences conservatively and understanding that flow abutment and flow overlap are difficult to distinguish in remote data sets; (3) taking care to
Dissipative systems and Bateman's Hamiltonian
International Nuclear Information System (INIS)
Pedrosa, I.A.; Baseia, B.
1983-01-01
It is shown, by using canonical transformations, that one can construct Bateman's Hamiltonian from a Hamiltonian for a conservative system and obtain a clear physical interpretation which explains the ambiguities emerging from its application to describe dissipative systems. (Author) [pt
Dissipative Effect and Tunneling Time
Directory of Open Access Journals (Sweden)
Samyadeb Bhattacharya
2011-01-01
Full Text Available The quantum Langevin equation has been studied for dissipative system using the approach of Ford et al. Here, we have considered the inverted harmonic oscillator potential and calculated the effect of dissipation on tunneling time, group delay, and the self-interference term. A critical value of the friction coefficient has been determined for which the self-interference term vanishes. This approach sheds new light on understanding the ion transport at nanoscale.
Dissipative motion perturbation theory and exact solutions
International Nuclear Information System (INIS)
Lodder, J.J.
1976-06-01
Dissipative motion of classical and quantum systems is described. In particular, attention is paid to systems coupled to the radiation field. A dissipative equation of motion for a particle in an arbitrary potential coupled to the radiation field is derived by means of perturbation theory. The usual divrgencies associated with the radiation field are eliminated by the application of a theory of generalized functions. This theory is developed as a subject in its own right and is presented independently. The introduction of classical zero-point energy makes the classical equa tion of motion for the phase density formally the same as its quantum counterpart. In particular, it is shown that the classical zero-point energy prevents the collapse of a classical H-atom and gives rise to a classical ground state. For systems with a quadratic Hamiltoian, the equation of motion can be solved exactly, even in the continuum limit for the radiation field, by means of the new generalized functions. Classically, the Fokker-Planck equation is found without any approximations, and quantum mechanically, the only approximation is the neglect of the change in the ground state caused by the interaction. The derivation is valid even for strong damping and arbitrarily short times. There is no transient time. For harmonic oscillators complete equivalence is shown to exist between quantum mechanics and classical mechanics with zero-point energy. A discussion of the derivation of the Pauli equation is given and perturbation theory is compared with the exact derivation. The exactly solvable models are used to calculate the Langevin force of the radiation field. The result is that the classical Langevin force is exactly delta-correlated, while the quantum Langevin force is not delta-correlated at all. The fluctuation-dissipation theorem is shown to be an exact consequence of the solution to the equations of motion
Friedli, Michael; Kirchgessner, Norbert; Grieder, Christoph; Liebisch, Frank; Mannale, Michael; Walter, Achim
2016-01-01
Plant growth is a good indicator of crop performance and can be measured by different methods and on different spatial and temporal scales. In this study, we measured the canopy height growth of maize (Zea mays), soybean (Glycine max) and wheat (Triticum aestivum) under field conditions by terrestrial laser scanning (TLS). We tested the hypotheses whether such measurements are capable to elucidate (1) differences in architecture that exist between genotypes; (2) genotypic differences between canopy height growth during the season and (3) short-term growth fluctuations (within 24 h), which could e.g. indicate responses to rapidly fluctuating environmental conditions. The canopies were scanned with a commercially available 3D laser scanner and canopy height growth over time was analyzed with a novel and simple approach using spherical targets with fixed positions during the whole season. This way, a high precision of the measurement was obtained allowing for comparison of canopy parameters (e.g. canopy height growth) at subsequent time points. Three filtering approaches for canopy height calculation from TLS were evaluated and the most suitable approach was used for the subsequent analyses. For wheat, high coefficients of determination (R(2)) of the linear regression between manually measured and TLS-derived canopy height were achieved. The temporal resolution that can be achieved with our approach depends on the scanned crop. For maize, a temporal resolution of several hours can be achieved, whereas soybean is ideally scanned only once per day, after leaves have reached their most horizontal orientation. Additionally, we could show for maize that plant architectural traits are potentially detectable with our method. The TLS approach presented here allows for measuring canopy height growth of different crops under field conditions with a high temporal resolution, depending on crop species. This method will enable advances in automated phenotyping for breeding and
Dissipation range turbulent cascades in plasmas
International Nuclear Information System (INIS)
Terry, P. W.; Almagri, A. F.; Forest, C. B.; Nornberg, M. D.; Rahbarnia, K.; Sarff, J. S.; Fiksel, G.; Hatch, D. R.; Jenko, F.; Prager, S. C.; Ren, Y.
2012-01-01
Dissipation range cascades in plasma turbulence are described and spectra are formulated from the scaled attenuation in wavenumber space of the spectral energy transfer rate. This yields spectra characterized by the product of a power law and exponential fall-off, applicable to all scales. Spectral indices of the power law and exponential fall-off depend on the scaling of the dissipation, the strength of the nonlinearity, and nonlocal effects when dissipation rates of multiple fluctuation fields are different. The theory is used to derive spectra for MHD turbulence with magnetic Prandtl number greater than unity, extending previous work. The theory is also applied to generic plasma turbulence by considering the spectrum from damping with arbitrary wavenumber scaling. The latter is relevant to ion temperature gradient turbulence modeled by gyrokinetics. The spectrum in this case has an exponential component that becomes weaker at small scale, giving a power law asymptotically. Results from the theory are compared to three very different types of turbulence. These include the magnetic plasma turbulence of the Madison Symmetric Torus, the MHD turbulence of liquid metal in the Madison Dynamo Experiment, and gyrokinetic simulation of ion temperature gradient turbulence.
Low Energy Dissipation Nano Device Research
Yu, Jenny
2015-03-01
The development of research on energy dissipation has been rapid in energy efficient area. Nano-material power FET is operated as an RF power amplifier, the transport is ballistic, noise is limited and power dissipation is minimized. The goal is Green-save energy by developing the Graphene and carbon nantube microwave and high performance devices. Higher performing RF amplifiers can have multiple impacts on broadly field, for example communication equipment, (such as mobile phone and RADAR); higher power density and lower power dissipation will improve spectral efficiency which translates into higher system level bandwidth and capacity for communications equipment. Thus, fundamental studies of power handling capabilities of new RF (nano)technologies can have broad, sweeping impact. Because it is critical to maximizing the power handling ability of grephene and carbon nanotube FET, the initial task focuses on measuring and understanding the mechanism of electrical breakdown. We aim specifically to determine how the breakdown voltage in graphene and nanotubes is related to the source-drain spacing, electrode material and thickness, and substrate, and thus develop reliable statistics on the breakdown mechanism and probability.
Magnetic intermittency of solar wind turbulence in the dissipation range
Pei, Zhongtian; He, Jiansen; Tu, Chuanyi; Marsch, Eckart; Wang, Linghua
2016-04-01
The feature, nature, and fate of intermittency in the dissipation range are an interesting topic in the solar wind turbulence. We calculate the distribution of flatness for the magnetic field fluctuations as a functionof angle and scale. The flatness distribution shows a "butterfly" pattern, with two wings located at angles parallel/anti-parallel to local mean magnetic field direction and main body located at angles perpendicular to local B0. This "butterfly" pattern illustrates that the flatness profile in (anti-) parallel direction approaches to the maximum value at larger scale and drops faster than that in perpendicular direction. The contours for probability distribution functions at different scales illustrate a "vase" pattern, more clear in parallel direction, which confirms the scale-variation of flatness and indicates the intermittency generation and dissipation. The angular distribution of structure function in the dissipation range shows an anisotropic pattern. The quasi-mono-fractal scaling of structure function in the dissipation range is also illustrated and investigated with the mathematical model for inhomogeneous cascading (extended p-model). Different from the inertial range, the extended p-model for the dissipation range results in approximate uniform fragmentation measure. However, more complete mathematicaland physical model involving both non-uniform cascading and dissipation is needed. The nature of intermittency may be strong structures or large amplitude fluctuations, which may be tested with magnetic helicity. In one case study, we find the heating effect in terms of entropy for large amplitude fluctuations seems to be more obvious than strong structures.
Reddy, S Navakishore; Gupta, Suman; Gajbhiye, Vijay T
2013-09-01
The dissipation of pyraclostrobin, a strobilurin fungicide, in soil was found to be influenced by soil moisture, organic matter content and microbial population. Among the different moisture regimes, dissipation was faster under submerged condition (T1/2 10 days) followed by field capacity (T1/2 28.7 days) and in dry soil (T1/2 41.8 days). Use of sludge at 5 % level to Inceptisol favoured a faster dissipation of pyraclostrobin, whereas a slower rate of dissipation was observed in partial organic matter removed soil as compared to normal soil. Slower rate of dissipation was also observed in sterile soil (T1/2 47 days) compared to normal soil. Pyraclostrobin dissipated faster in Vertisol (T1/2 21.8 days) than in Inceptisol (T1/2 28.7 days). No significant difference in the dissipation rate was observed at 1 and 10 μg g(-1) fortification levels.
Compaction shock dissipation in low density granular explosive
Energy Technology Data Exchange (ETDEWEB)
Rao, Pratap T.; Gonthier, Keith A., E-mail: gonthier@me.lsu.edu; Chakravarthy, Sunada [Mechanical and Industrial Engineering Department, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)
2016-06-14
The microstructure of granular explosives can affect dissipative heating within compaction shocks that can trigger combustion and initiate detonation. Because initiation occurs over distances that are much larger than the mean particle size, homogenized (macroscale) theories are often used to describe local thermodynamic states within and behind shocks that are regarded as the average manifestation of thermodynamic fields at the particle scale. In this paper, mesoscale modeling and simulation are used to examine how the initial packing density of granular HMX (C{sub 4}H{sub 8}N{sub 8}O{sub 8}) C{sub 4}H{sub 8}N{sub 8}O{sub 8} having a narrow particle size distribution influences dissipation within resolved, planar compaction shocks. The model tracks the evolution of thermomechanical fields within large ensembles of particles due to pore collapse. Effective shock profiles, obtained by averaging mesoscale fields over space and time, are compared with those given by an independent macroscale compaction theory that predicts the variation in effective thermomechanical fields within shocks due to an imbalance between the solid pressure and a configurational stress. Reducing packing density is shown to reduce the dissipation rate within shocks but increase the integrated dissipated work over shock rise times, which is indicative of enhanced sensitivity. In all cases, dissipated work is related to shock pressure by a density-dependent power law, and shock rise time is related to pressure by a power law having an exponent of negative one.
Dissipative structures and related methods
Langhorst, Benjamin R; Chu, Henry S
2013-11-05
Dissipative structures include at least one panel and a cell structure disposed adjacent to the at least one panel having interconnected cells. A deformable material, which may comprise at least one hydrogel, is disposed within at least one interconnected cell proximate to the at least one panel. Dissipative structures may also include a cell structure having interconnected cells formed by wall elements. The wall elements may include a mesh formed by overlapping fibers having apertures formed therebetween. The apertures may form passageways between the interconnected cells. Methods of dissipating a force include disposing at least one hydrogel in a cell structure proximate to at least one panel, applying a force to the at least one panel, and forcing at least a portion of the at least one hydrogel through apertures formed in the cell structure.
Balme, M. R.; Pathare, A.; Metzger, S. M.; Towner, M. C.; Lewis, S. R.; Spiga, A.; Fenton, L. K.; Renno, N. O.; Elliott, H. M.; Saca, F. A.; Michaels, T. I.; Russell, P.; Verdasca, J.
2012-11-01
Dust devils - convective vortices made visible by the dust and debris they entrain - are common in arid environments and have been observed on Earth and Mars. Martian dust devils have been identified both in images taken at the surface and in remote sensing observations from orbiting spacecraft. Observations from landing craft and orbiting instruments have allowed the dust devil translational forward motion (ground velocity) to be calculated, but it is unclear how these velocities relate to the local ambient wind conditions, for (i) only model wind speeds are generally available for Mars, and (ii) on Earth only anecdotal evidence exists that compares dust devil ground velocity with ambient wind velocity. If dust devil ground velocity can be reliably correlated to the ambient wind regime, observations of dust devils could provide a proxy for wind speed and direction measurements on Mars. Hence, dust devil ground velocities could be used to probe the circulation of the martian boundary layer and help constrain climate models or assess the safety of future landing sites. We present results from a field study of terrestrial dust devils performed in the southwest USA in which we measured dust devil horizontal velocity as a function of ambient wind velocity. We acquired stereo images of more than a 100 active dust devils and recorded multiple size and position measurements for each dust devil. We used these data to calculate dust devil translational velocity. The dust devils were within a study area bounded by 10 m high meteorology towers such that dust devil speed and direction could be correlated with the local ambient wind speed and direction measurements. Daily (10:00-16:00 local time) and 2-h averaged dust devil ground speeds correlate well with ambient wind speeds averaged over the same period. Unsurprisingly, individual measurements of dust devil ground speed match instantaneous measurements of ambient wind speed more poorly; a 20-min smoothing window applied to
Dissipative heavy-ion collisions
International Nuclear Information System (INIS)
Feldmeier, H.T.
1985-01-01
This report is a compilation of lecture notes of a series of lectures held at Argonne National Laboratory in October and November 1984. The lectures are a discussion of dissipative phenomena as observed in collisions of atomic nuclei. The model is based on a system which has initially zero temperature and the initial energy is kinetic and binding energy. Collisions excite the nuclei, and outgoing fragments or the compound system deexcite before they are detected. Brownian motion is used to introduce the concept of dissipation. The master equation and the Fokker-Planck equation are derived. 73 refs., 59 figs
New Measure of the Dissipation Region in Collisionless Magnetic Reconnection
International Nuclear Information System (INIS)
Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Kuznetsova, Masha
2011-01-01
A new measure to identify a small-scale dissipation region in collisionless magnetic reconnection is proposed. The energy transfer from the electromagnetic field to plasmas in the electron's rest frame is formulated as a Lorentz-invariant scalar quantity. The measure is tested by two-dimensional particle-in-cell simulations in typical configurations: symmetric and asymmetric reconnection, with and without the guide field. The innermost region surrounding the reconnection site is accurately located in all cases. We further discuss implications for nonideal MHD dissipation.
New Measure of the Dissipation Region in Collisionless Magnetic Reconnection
Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Kuznetsova, Masha
2012-01-01
A new measure to identify a small-scale dissipation region in collisionless magnetic reconnection is proposed. The energy transfer from the electromagnetic field to plasmas in the electron s rest frame is formulated as a Lorentz-invariant scalar quantity. The measure is tested by two-dimensional particle-in-cell simulations in typical configurations: symmetric and asymmetric reconnection, with and without the guide field. The innermost region surrounding the reconnection site is accurately located in all cases. We further discuss implications for nonideal MHD dissipation.
Wave-number spectra and intermittency in the terrestrial foreshock region.
Narita, Y; Glassmeier, K-H; Treumann, R A
2006-11-10
Wave-number spectra of magnetic field fluctuations are directly determined in the terrestrial foreshock region (upstream of a quasiparallel collisionless shock wave) using four-point Cluster spacecraft measurements. The spectral curve is characterized by three ranges reminiscent of turbulence: energy injection, inertial, and dissipation range. The spectral index for the inertial range spectrum is close to Kolmogorov's slope, -5/3. On the other hand, the fluctuations are highly anisotropic and intermittent perpendicular to the mean magnetic field direction. These results suggest that the foreshock is in a weakly turbulent and intermittent state in which parallel propagating Alfvén waves interact with one another, resulting in the phase coherence or the intermittency.
ENERGY DISSIPATION PROCESSES IN SOLAR WIND TURBULENCE
Energy Technology Data Exchange (ETDEWEB)
Wang, Y.; Wei, F. S.; Feng, X. S.; Sun, T. R.; Zuo, P. B. [SIGMA Weather Group, State Key Laboratory for Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China); Xu, X. J. [Space Science Institute, Macau University of Science and Technology, Macao (China); Zhang, J., E-mail: yw@spaceweather.ac.cn [School of Physics, Astronomy and Computational Sciences, George Mason University, 4400 University Drive, MSN 3F3, Fairfax, Virginia 22030 (United States)
2015-12-15
Turbulence is a chaotic flow regime filled by irregular flows. The dissipation of turbulence is a fundamental problem in the realm of physics. Theoretically, dissipation ultimately cannot be achieved without collisions, and so how turbulent kinetic energy is dissipated in the nearly collisionless solar wind is a challenging problem. Wave particle interactions and magnetic reconnection (MR) are two possible dissipation mechanisms, but which mechanism dominates is still a controversial topic. Here we analyze the dissipation region scaling around a solar wind MR region. We find that the MR region shows unique multifractal scaling in the dissipation range, while the ambient solar wind turbulence reveals a monofractal dissipation process for most of the time. These results provide the first observational evidences for intermittent multifractal dissipation region scaling around a MR site, and they also have significant implications for the fundamental energy dissipation process.
Dissipative effects in Multilevel Systems
Energy Technology Data Exchange (ETDEWEB)
Solomon, A I [Department of Physics and Astronomy, Open University, Milton Keynes MK7 6AA (United Kingdom); Schirmer, S G [Department of Applied Maths and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA (United Kingdom)
2007-11-15
Dissipation is sometimes regarded as an inevitable and regrettable presence in the real evolution of a quantum system. However, the effects may not always be malign, although often non-intuitive and may even be beneficial. In this note we we display some of these effects for N-level systems, where N = 2,3,4. We start with an elementary introduction to dissipative effects on the Bloch Sphere, and its interior, the Bloch Ball, for a two-level system. We describe explicitly the hamiltonian evolution as well as the purely dissipative dynamics, in the latter case giving the t {yields} {infinity} limits of the motion. This discussion enables us to provide an intuitive feeling for the measures of control-reachable states. For the three-level case we discuss the impossibility of isolating a two-level (qubit) subsystem; this is a Bohm-Aharonov type consequence of dissipation. We finally exemplify the four-level case by giving constraints on the decay of two-qubit entanglement.
Engineering dissipation with phononic spectral hole burning
Behunin, R. O.; Kharel, P.; Renninger, W. H.; Rakich, P. T.
2017-03-01
Optomechanics, nano-electromechanics, and integrated photonics have brought about a renaissance in phononic device physics and technology. Central to this advance are devices and materials supporting ultra-long-lived photonic and phononic excitations that enable novel regimes of classical and quantum dynamics based on tailorable photon-phonon coupling. Silica-based devices have been at the forefront of such innovations for their ability to support optical excitations persisting for nearly 1 billion cycles, and for their low optical nonlinearity. While acoustic phonon modes can persist for a similar number of cycles in crystalline solids at cryogenic temperatures, it has not been possible to achieve such performance in silica, as silica becomes acoustically opaque at low temperatures. We demonstrate that these intrinsic forms of phonon dissipation are greatly reduced (by >90%) by nonlinear saturation using continuous drive fields of disparate frequencies. The result is a form of steady-state phononic spectral hole burning that produces a wideband transparency window with optically generated phonon fields of modest (nW) powers. We developed a simple model that explains both dissipative and dispersive changes produced by phononic saturation. Our studies, conducted in a microscale device, represent an important step towards engineerable phonon dynamics on demand and the use of glasses as low-loss phononic media.
Scalar dissipation rate and dissipative anomaly in isotropic turbulence
International Nuclear Information System (INIS)
Donzis, D.A.; Sreenivasan, K.R.; Yeung, P.K.
2006-12-01
We examine available data from experiment and recent numerical simulations to explore the supposition that the scalar dissipation rate in turbulence becomes independent of the fluid viscosity when the viscosity is small and of scalar diffusivity when the diffusivity is small. The data are interpreted in the context of semi-empirical spectral theory of Obukhov and Corrsin when the Schmidt number, Sc, is below unity, and of Batchelor's theory when Sc is above unity. Practical limits in terms of the Taylor-microscale Reynolds number, R λ , as well as Sc, are deduced for scalar dissipation to become sensibly independent of molecular properties. In particular, we show that such an asymptotic state is reached if R λ Sc 1/2 >> 1 for Sc λ 1. (author)
Dissipation of Wave Energy by Cohesive Sediments
National Research Council Canada - National Science Library
Kaihatu, James M; Sheremet, Alexandru
2004-01-01
Wave energy dissipation by bottom muds is studied. A dissipation mechanism which contains explicit expressions of wavenumber modification due to a viscous bottom fluid is incorporated into a nonlinear wave shoaling model...
Dissipation, intermittency, and singularities in incompressible turbulent flows
Debue, P.; Shukla, V.; Kuzzay, D.; Faranda, D.; Saw, E.-W.; Daviaud, F.; Dubrulle, B.
2018-05-01
We examine the connection between the singularities or quasisingularities in the solutions of the incompressible Navier-Stokes equation (INSE) and the local energy transfer and dissipation, in order to explore in detail how the former contributes to the phenomenon of intermittency. We do so by analyzing the velocity fields (a) measured in the experiments on the turbulent von Kármán swirling flow at high Reynolds numbers and (b) obtained from the direct numerical simulations of the INSE at a moderate resolution. To compute the local interscale energy transfer and viscous dissipation in experimental and supporting numerical data, we use the weak solution formulation generalization of the Kármán-Howarth-Monin equation. In the presence of a singularity in the velocity field, this formulation yields a nonzero dissipation (inertial dissipation) in the limit of an infinite resolution. Moreover, at finite resolutions, it provides an expression for local interscale energy transfers down to the scale where the energy is dissipated by viscosity. In the presence of a quasisingularity that is regularized by viscosity, the formulation provides the contribution to the viscous dissipation due to the presence of the quasisingularity. Therefore, our formulation provides a concrete support to the general multifractal description of the intermittency. We present the maps and statistics of the interscale energy transfer and show that the extreme events of this transfer govern the intermittency corrections and are compatible with a refined similarity hypothesis based on this transfer. We characterize the probability distribution functions of these extreme events via generalized Pareto distribution analysis and find that the widths of the tails are compatible with a similarity of the second kind. Finally, we make a connection between the topological and the statistical properties of the extreme events of the interscale energy transfer field and its multifractal properties.
Dissipation and nuclear collective motion
International Nuclear Information System (INIS)
Hofmann, Helmut; Jensen, A.S.; Ngo, Christian; Siemens, P.J.; California Univ., Berkeley
1979-01-01
This contribution is intended to give a brief summary of a forthcoming paper which shall review extensively the linear response theory for dissipation and statistical fluctuations as well as its application to heavy-ion collisions. It shall contain new results on the following subjects: numerical computations of response functions and transport coefficients; dissipation in a self-consistent treatment of harmonic vibrations; introduction of collective variables within a quantum theory. The method used consists of an extended version of the Bohm and Pines treatment of the electron gas. It allows to deduce a quantum Hamiltonian for the collective and intrinsic motion including coupling terms; discussion and solution of a quantal Master equation for non-linear collective motion. Additionally, a somewhat elaborate discussion of the problems of irreversibility is given, especially in connection to a treatment within the moving basis
Kinetic approach to relativistic dissipation
Gabbana, A.; Mendoza, M.; Succi, S.; Tripiccione, R.
2017-08-01
Despite a long record of intense effort, the basic mechanisms by which dissipation emerges from the microscopic dynamics of a relativistic fluid still elude complete understanding. In particular, several details must still be finalized in the pathway from kinetic theory to hydrodynamics mainly in the derivation of the values of the transport coefficients. In this paper, we approach the problem by matching data from lattice-kinetic simulations with analytical predictions. Our numerical results provide neat evidence in favor of the Chapman-Enskog [The Mathematical Theory of Non-Uniform Gases, 3rd ed. (Cambridge University Press, Cambridge, U.K., 1970)] procedure as suggested by recent theoretical analyses along with qualitative hints at the basic reasons why the Chapman-Enskog expansion might be better suited than Grad's method [Commun. Pure Appl. Math. 2, 331 (1949), 10.1002/cpa.3160020403] to capture the emergence of dissipative effects in relativistic fluids.
Nuclear Dissipation from Fission Time
International Nuclear Information System (INIS)
Gontchar, I.; Morjean, M.; Basnary, S.
2000-01-01
Fission times, pre-scission neutron multiplicities and GDR pre-scission γ-ray multiplicities measured for uranium or thorium nuclei formed with temperatures T ∼ 1.8 MeV have been compared with calculations performed with CDSM2, a two-dimensional dynamical model combined with a statistical one. Among the three experimental approaches considered, fission times give access to the most precise pieces of information on nuclear dissipation at high excitation energy. For the temperature range under consideration, an agreement between the model and data is achieved if one-body dissipation is used with a strength factor k red ∼ 0.45 ± 0.10 applied to the wall term for the mononuclear configuration. (authors)
Collisionless dissipation of Langmuir turbulence
International Nuclear Information System (INIS)
Erofeev, V.I.
2002-01-01
An analysis of two experimental observations of Langmuir wave collapse is performed. The corresponding experimental data are shown to give evidence against the collapse. The physical reason for preventing the collapses is found to be the nonresonant electron diffusion in momentums. In this process, plasma thermal electrons are efficiently heated at the expense of wave energy, and intense collisionless wave dissipation takes place. The basic reason of underestimation of this phenomenon in traditional theory is shown to be the substitution of real plasma by a plasma probabilistic ensemble. A theory of nonresonant electron diffusion in a single collisionless plasma is developed. It is shown that corresponding collisionless wave dissipation may arrest spectral energy transfer towards small wave numbers
Anisotropy dissipation in quantum cosmology
International Nuclear Information System (INIS)
Calzetta, E.; Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires, Argentina)
1991-01-01
We study the issue of decoherence and dissipation in the wave function of the Universe for a Bianchi type-I universe with classical and quantum matter. We obtain a coarse-grained description by tracing over the matter degrees of freedom. Provided that for small universes the wave function of the universe is concentrated on a neighborhood of the isotropic configuration, then the coarse-grained density matrix of the universe will show an even more marked peak around isotropy for large universes. In this sense we can say that, while decoherence makes the reduced density matrix of the universe diagonal, dissipation causes the universe to be isotropic with a high probability for large radii
Simulation of coupled electromagnetic and heat dissipation problems
Janssen, H.H.J.M.; Maten, ter E.J.W.; Houwelingen, van D.
1994-01-01
A description is given of an integrated simulation environment for the solution of coupled electromagnetic and heat dissipation problems in two dimensions, in particular for the field of induction heating, dielectric heating, and hysteresis heating. The equations are coupled because the most
Characterizing Terrestrial Exoplanets
Meadows, V. S.; Lustig-Yaeger, J.; Lincowski, A.; Arney, G. N.; Robinson, T. D.; Schwieterman, E. W.; Deming, L. D.; Tovar, G.
2017-11-01
We will provide an overview of the measurements, techniques, and upcoming missions required to characterize terrestrial planet environments and evolution, and search for signs of habitability and life.
Dissipative dark matter halos: The steady state solution
Foot, R.
2018-02-01
Dissipative dark matter, where dark matter particle properties closely resemble familiar baryonic matter, is considered. Mirror dark matter, which arises from an isomorphic hidden sector, is a specific and theoretically constrained scenario. Other possibilities include models with more generic hidden sectors that contain massless dark photons [unbroken U (1 ) gauge interactions]. Such dark matter not only features dissipative cooling processes but also is assumed to have nontrivial heating sourced by ordinary supernovae (facilitated by the kinetic mixing interaction). The dynamics of dissipative dark matter halos around rotationally supported galaxies, influenced by heating as well as cooling processes, can be modeled by fluid equations. For a sufficiently isolated galaxy with a stable star formation rate, the dissipative dark matter halos are expected to evolve to a steady state configuration which is in hydrostatic equilibrium and where heating and cooling rates locally balance. Here, we take into account the major cooling and heating processes, and numerically solve for the steady state solution under the assumptions of spherical symmetry, negligible dark magnetic fields, and that supernova sourced energy is transported to the halo via dark radiation. For the parameters considered, and assumptions made, we were unable to find a physically realistic solution for the constrained case of mirror dark matter halos. Halo cooling generally exceeds heating at realistic halo mass densities. This problem can be rectified in more generic dissipative dark matter models, and we discuss a specific example in some detail.
Signatures of a dissipative phase transition in photon correlation measurements
Fink, Thomas; Schade, Anne; Höfling, Sven; Schneider, Christian; Imamoglu, Ataç
2018-04-01
Understanding and characterizing phase transitions in driven-dissipative systems constitutes a new frontier for many-body physics1-8. A generic feature of dissipative phase transitions is a vanishing gap in the Liouvillian spectrum9, which leads to long-lived deviations from the steady state as the system is driven towards the transition. Here, we show that photon correlation measurements can be used to characterize the corresponding critical slowing down of non-equilibrium dynamics. We focus on the extensively studied phenomenon of optical bistability in GaAs cavity polaritons10,11, which can be described as a first-order dissipative phase transition12-14. Increasing the excitation strength towards the bistable range results in an increasing photon-bunching signal along with a decay time that is prolonged by more than nine orders of magnitude as compared with that of single polaritons. In the limit of strong polariton interactions leading to pronounced quantum fluctuations, the mean-field bistability threshold is washed out. Nevertheless, the functional form with which the Liouvillian gap closes as the thermodynamic limit is approached provides a signature of the emerging dissipative phase transition. Our results establish photon correlation measurements as an invaluable tool for studying dynamical properties of dissipative phase transitions without requiring phase-sensitive interferometric measurements.
Estimating Half-Lives for Pesticide Dissipation from Plants
DEFF Research Database (Denmark)
Fantke, Peter; Gillespie, Brenda W.; Juraske, Ronnie
2014-01-01
Pesticide risk and impact assessment models critically rely on and are sensitive to information describing dissipation from plants. Despite recent progress, experimental data are not available for all relevant pesticide−plant combinations, and currently no model predicting plant dissipation...... accounts for the influence of substance properties, plant characteristics, temperature, and study conditions. In this study, we propose models to estimate half-lives for pesticide dissipation from plants and provide recommendations for how to use our results. On the basis of fitting experimental...... under field conditions. Half-lives range from 0.2 days for pyrethrins to 31 days for dalapon. Parameter estimates are provided to correct for specific plant species, temperatures, and study conditions. Finally, we propose a predictive regression model for pesticides without available measured...
Logarithmic scaling in the near-dissipation range of turbulence
International Nuclear Information System (INIS)
Sreenivasan, K.R.; Bershadskii, A.
2006-12-01
A logarithmic scaling for structure functions, in the form S p ∼ [ln(r/η)] ζp , where η is the Kolmogorov dissipation scale and ζ p are the scaling exponents, is suggested for the statistical description of the near-dissipation range for which classical power-law scaling does not apply. From experimental data at moderate Reynolds numbers, it is shown that the logarithmic scaling, deduced from general considerations for the near-dissipation range, covers almost the entire range of scales (about two decades) of structure functions, for both velocity and passive scalar fields. This new scaling requires two empirical constants, just as the classical scaling does, and can be considered the basis for extended self-similarity. (author)
Nanomechanical dissipation at a tip-induced Kondo onset
Baruselli, Pier Paolo; Fabrizio, Michele; Tosatti, Erio
2017-08-01
The onset or demise of Kondo effect in a magnetic impurity on a metal surface can be triggered, as sometimes observed, by the simple mechanical nudging of a tip. Such a mechanically driven quantum phase transition must reflect in a corresponding mechanical dissipation peak; yet, this kind of signature has not been focused upon so far. Aiming at the simplest theoretical modeling, we treat the impurity as an Anderson impurity model, the tip action as a hybridization switching, and solve the problem by numerical renormalization group. Studying this model as function of temperature and magnetic field we are able to isolate the Kondo contribution to dissipation. While that is, reasonably, of the order of the Kondo energy, its temperature evolution shows a surprisingly large tail even above the Kondo temperature. The detectability of Kondo mechanical dissipation in atomic force microscopy is also discussed.
International Nuclear Information System (INIS)
Patel, V.L.
1977-01-01
The Glossary is designed to be a technical dictionary that will provide solar workers of various specialties, students, other astronomers and theoreticians with concise information on the nature and the properties of phenomena of solar and solar-terrestrial physics. Each term, or group of related terms, is given a concise phenomenological and quantitative description, including the relationship to other phenomena and an interpretation in terms of physical processes. The references are intended to lead the non-specialist reader into the literature. This section deals with: geomagnetic field; coordinate systems; geomagnetic indices; Dst index; auroral electrojet index AE; daily, 27-day and semi-annual variations of geomagnetic field; micropulsation; geomagnetic storms; storm sudden commencement (SSC) or sudden commencement (SC); initial phase; ring current; sudden impulses; ionosphere; D region; polar cap absorption; sudden ionospheric disturbance; E region; sporadic E; equatorial electrojet; solar flare effect; F 1 and F 2 regions; spread F; travelling ionospheric disturbances; magnetosphere; magnetospheric coordinate systems; plasmasphere; magnetosheath; magnetospheric tail; substorm; radiation belts or Van Allen belts; whistlers; VLF emissions; aurora; auroral forms; auroral oval and auroral zones; auroral intensity; stable auroral red arcs; pulsing aurora; polar glow aurora; and airglow. (B.R.H.)
Dissipative N-point-vortex Models in the Plane
Shashikanth, Banavara N.
2010-02-01
A method is presented for constructing point vortex models in the plane that dissipate the Hamiltonian function at any prescribed rate and yet conserve the level sets of the invariants of the Hamiltonian model arising from the SE (2) symmetries. The method is purely geometric in that it uses the level sets of the Hamiltonian and the invariants to construct the dissipative field and is based on elementary classical geometry in ℝ3. Extension to higher-dimensional spaces, such as the point vortex phase space, is done using exterior algebra. The method is in fact general enough to apply to any smooth finite-dimensional system with conserved quantities, and, for certain special cases, the dissipative vector field constructed can be associated with an appropriately defined double Nambu-Poisson bracket. The most interesting feature of this method is that it allows for an infinite sequence of such dissipative vector fields to be constructed by repeated application of a symmetric linear operator (matrix) at each point of the intersection of the level sets.
Dissipation Mechanisms and Particle Acceleration at the Earth's Bow Shock
Desai, M. I.; Burch, J. L.; Broll, J. M.; Genestreti, K.; Torbert, R. B.; Ergun, R.; Wei, H.; Giles, B. L.; Russell, C. T.; Phan, T.; Chen, L. J.; Lai, H.; Wang, S.; Schwartz, S. J.; Allen, R. C.; Mauk, B.; Gingell, I.
2017-12-01
NASA's Magnetospheric Multiscale (MMS) mission has four spacecraft equipped with identical state-of-the-art instruments that acquire magnetic and electric field, plasma wave, and particle data at unprecedented temporal resolution to study the fundamental physics of magnetic reconnection in the Earth's magnetosphere. During Phase 1a, MMS also encountered and crossed the Earth's bow shock more than 300 times. We use burst data during 2 bow shock crossings to shed new light on key open questions regarding the formation, evolution, and dissipation mechanisms at collisionless shocks. Specifically, we focus on two events that exhibit clear differences in the ion and electron properties, the associated wave activity, and, therefore in the nature of the dissipation. In the case of a quasi-perpendicular, low beta shock crossing, we find that the dissipation processes are most likely associated with field-aligned electron beams that are coincident with high frequency electrostatic waves. On the other hand, the dissipation processes at an oblique, high beta shock crossing are largely governed by the quasi-static electric field and generation of magnetosonic whistler waves that result in perpendicular temperature anisotropy for the electrons. We also discuss the implications of these results for ion heating, reflection, and particle acceleration.
Grazing livestock are exposed to terrestrial cyanobacteria
McGorum , Bruce C; Pirie , R Scott; Glendinning , Laura; McLachlan , Gerry; Metcalf , James S; Banack , Sandra A; Cox , Paul A; Codd , Geoffrey A
2015-01-01
While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in al...
Dean Pearson; Deborah Finch
2011-01-01
Within the Interior West, terrestrial vertebrates do not represent a large number of invasive species relative to invasive weeds, aquatic vertebrates, and invertebrates. However, several invasive terrestrial vertebrate species do cause substantial economic and ecological damage in the U.S. and in this region (Pimental 2000, 2007; Bergman and others 2002; Finch and...
Entanglement replication in driven dissipative many-body systems.
Zippilli, S; Paternostro, M; Adesso, G; Illuminati, F
2013-01-25
We study the dissipative dynamics of two independent arrays of many-body systems, locally driven by a common entangled field. We show that in the steady state the entanglement of the driving field is reproduced in an arbitrarily large series of inter-array entangled pairs over all distances. Local nonclassical driving thus realizes a scale-free entanglement replication and long-distance entanglement distribution mechanism that has immediate bearing on the implementation of quantum communication networks.
Designing Biomimetic, Dissipative Material Systems
Energy Technology Data Exchange (ETDEWEB)
Balazs, Anna C. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Whitesides, George M. [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology; Brinker, C. Jeffrey [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering. Dept. of Chemistry. Dept. of Molecular Genetics and Microbiology. Center for Micro-Engineered Materials; Aranson, Igor S. [UChicago, LLC., Argonne, IL (United States); Chaikin, Paul [New York Univ. (NYU), NY (United States). Dept. of Physics; Dogic, Zvonimir [Brandeis Univ., Waltham, MA (United States). Dept. of Physics; Glotzer, Sharon [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering. Dept. of Materials Science and Engineering. Dept. of Macromolecular Science and Engineering Physics; Hammer, Daniel [Univ. of Pennsylvania, Philadelphia, PA (United States). School of Engineering and Applied Science; Irvine, Darrell [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Materials Science and Engineering and Biological Engineering; Little, Steven R. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Olvera de la Cruz, Monica [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Parikh, Atul N. [Univ. of California, Davis, CA (United States). Dept. of Biomedical Engineering. Dept. of Chemical Engineering and Materials Science; Stupp, Samuel [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering. Dept. of Chemistry. Dept. of Medicine. Dept. of Biomedical Engineering; Szostak, Jack [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology
2016-01-21
Throughout human history, new materials have been the foundation of transformative technologies: from bronze, paper, and ceramics to steel, silicon, and polymers, each material has enabled far-reaching advances. Today, another new class of materials is emerging—one with both the potential to provide radically new functions and to challenge our notion of what constitutes a “material”. These materials would harvest, transduce, or dissipate energy to perform autonomous, dynamic functions that mimic the behaviors of living organisms. Herein, we discuss the challenges and benefits of creating “dissipative” materials that can potentially blur the boundaries between living and non-living matter.
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
Dissipation of Turbulence in the Wake of a Wind Turbine
Lundquist, J. K.; Bariteau, L.
2015-02-01
The wake of a wind turbine is characterized by increased turbulence and decreased wind speed. Turbines are generally deployed in large groups in wind farms, and so the behaviour of an individual wake as it merges with other wakes and propagates downwind is critical in assessing wind-farm power production. This evolution depends on the rate of turbulence dissipation in the wind-turbine wake, which has not been previously quantified in field-scale measurements. In situ measurements of winds and turbulence dissipation from the wake region of a multi-MW turbine were collected using a tethered lifting system (TLS) carrying a payload of high-rate turbulence probes. Ambient flow measurements were provided from sonic anemometers on a meteorological tower located near the turbine. Good agreement between the tower measurements and the TLS measurements was established for a case without a wind-turbine wake. When an operating wind turbine is located between the tower and the TLS so that the wake propagates to the TLS, the TLS measures dissipation rates one to two orders of magnitude higher in the wake than outside of the wake. These data, collected between two and three rotor diameters downwind of the turbine, document the significant enhancement of turbulent kinetic energy dissipation rate within the wind-turbine wake. These wake measurements suggest that it may be useful to pursue modelling approaches that account for enhanced dissipation. Comparisons of wake and non-wake dissipation rates to mean wind speed, wind-speed variance, and turbulence intensity are presented to facilitate the inclusion of these measurements in wake modelling schemes.
Natural approach to quantum dissipation
Taj, David; Öttinger, Hans Christian
2015-12-01
The dissipative dynamics of a quantum system weakly coupled to one or several reservoirs is usually described in terms of a Lindblad generator. The popularity of this approach is certainly due to the linear character of the latter. However, while such linearity finds justification from an underlying Hamiltonian evolution in some scaling limit, it does not rely on solid physical motivations at small but finite values of the coupling constants, where the generator is typically used for applications. The Markovian quantum master equations we propose are instead supported by very natural thermodynamic arguments. They themselves arise from Markovian master equations for the system and the environment which preserve factorized states and mean energy and generate entropy at a non-negative rate. The dissipative structure is driven by an entropic map, called modular, which introduces nonlinearity. The generated modular dynamical semigroup (MDS) guarantees for the positivity of the time evolved state the correct steady state properties, the positivity of the entropy production, and a positive Onsager matrix with symmetry relations arising from Green-Kubo formulas. We show that the celebrated Davies Lindblad generator, obtained through the Born and the secular approximations, generates a MDS. In doing so we also provide a nonlinear MDS which is supported by a weak coupling argument and is free from the limitations of the Davies generator.
International Nuclear Information System (INIS)
Bremhorst, K.; Listijono, J.B.H.; Krebs, L.; Mueller, U.
1989-01-01
A previously developed diffusivity based based model, for the prediction of mean and fluctuating temperatures in water flow downstream of a multi-bore jet block in which one jet is heated, is applied to a flow of sodium in apparatus of similar geometry. Some measurements not readily possible in sodium or water flows for this geometry are made using air in order to verify assumptions used in the model. The earlier derived mathematical model is modified to remove assumptions relating to turbulence. Reynolds number and turbulence Peclet number in the relationship between velocity and temperature microscales. Spalding's model, relating fluctuating velocity and temperature dissipation rates, is tested. A significant effect on this relationship due to the low Prandtl number of liquid sodium is identified. Measurements performed behind a multi-bore jet block with air as the working fluid have verified the non-isotropic nature of the large-scale flow. Results clearly show that measurements performed in water can be transferred to liquid sodium provided that molecular diffusion is included in the mean temperature equation, allowance is made for the Prandtl number effect on the dissipation time scale ratio and the coefficient of gradient diffusion of mean square temperature fluctuations is assumed equal to the eddy diffusivity of heat. (author)
Particle Acceleration in Dissipative Pulsar Magnetospheres
Kazanas, Z.; Kalapotharakos, C.; Harding, A.; Contopoulos, I.
2012-01-01
Pulsar magnetospheres represent unipolar inductor-type electrical circuits at which an EM potential across the polar cap (due to the rotation of their magnetic field) drives currents that run in and out of the polar cap and close at infinity. An estimate ofthe magnitude of this current can be obtained by dividing the potential induced across the polar cap V approx = B(sub O) R(sub O)(Omega R(sub O)/c)(exp 2) by the impedance of free space Z approx eq 4 pi/c; the resulting polar cap current density is close to $n {GJ} c$ where $n_{GJ}$ is the Goldreich-Julian (GJ) charge density. This argument suggests that even at current densities close to the GJ one, pulsar magnetospheres have a significant component of electric field $E_{parallel}$, parallel to the magnetic field, a condition necessary for particle acceleration and the production of radiation. We present the magnetic and electric field structures as well as the currents, charge densities, spin down rates and potential drops along the magnetic field lines of pulsar magnetospheres which do not obey the ideal MHD condition $E cdot B = 0$. By relating the current density along the poloidal field lines to the parallel electric field via a kind of Ohm's law $J = sigma E_{parallel}$ we study the structure of these magnetospheres as a function of the conductivity $sigma$. We find that for $sigma gg OmegaS the solution tends to the (ideal) Force-Free one and to the Vacuum one for $sigma 11 OmegaS. Finally, we present dissipative magnetospheric solutions with spatially variable $sigma$ that supports various microphysical properties and are compatible with the observations.
Optimal coherent control of dissipative N-level systems
International Nuclear Information System (INIS)
Jirari, H.; Poetz, W.
2005-01-01
General optimal coherent control of dissipative N-level systems in the Markovian time regime is formulated within Pointryagin's principle and the Lindblad equation. In the present paper, we study feasibility and limitations of steering of dissipative two-, three-, and four-level systems from a given initial pure or mixed state into a desired final state under the influence of an external electric field. The time evolution of the system is computed within the Lindblad equation and a conjugate gradient method is used to identify optimal control fields. The influence of both field-independent population and polarization decay on achieving the objective is investigated in systematic fashion. It is shown that, for realistic dephasing times, optimum control fields can be identified which drive the system into the target state with very high success rate and in economical fashion, even when starting from a poor initial guess. Furthermore, the optimal fields obtained give insight into the system dynamics. However, if decay rates of the system cannot be subjected to electromagnetic control, the dissipative system cannot be maintained in a specific pure or mixed state, in general
Quantum correlations and limit cycles in the driven-dissipative Heisenberg lattice
Owen, E. T.; Jin, J.; Rossini, D.; Fazio, R.; Hartmann, M. J.
2018-04-01
Driven-dissipative quantum many-body systems have attracted increasing interest in recent years as they lead to novel classes of quantum many-body phenomena. In particular, mean-field calculations predict limit cycle phases, slow oscillations instead of stationary states, in the long-time limit for a number of driven-dissipative quantum many-body systems. Using a cluster mean-field and a self-consistent Mori projector approach, we explore the persistence of such limit cycles as short range quantum correlations are taken into account in a driven-dissipative Heisenberg model.
Introduced Terrestrial Species (Future)
U.S. Environmental Protection Agency — These data represent predicted future potential distributions of terrestrial plants, animals, and pathogens non-native to the Middle-Atlantic region. These data are...
Variational principles for dissipative waves
Dodin, I. Y.; Ruiz, D. E.
2016-10-01
Variational methods are a powerful tool in plasma theory. However, their applications are typically restricted to conservative systems or require doubling of variables, which often contradicts the purpose of the variational approach altogether. We show that these restrictions can be relaxed for some classes of dynamical systems that are of practical interest in plasma physics, particularly including dissipative plasma waves. Applications will be discussed to calculating dispersion relations and modulational dynamics of individual plasma waves and wave ensembles. The work was supported by the NNSA SSAA Program through DOE Research Grant No. DE-NA0002948, by the U.S. DOE through Contract No. DE-AC02-09CH11466, and by the U.S. DOD NDSEG Fellowship through Contract No. 32-CFR-168a.
Terrestrial ecosystems and biodiversity
CSIR Research Space (South Africa)
Davis-Reddy, Claire
2017-10-01
Full Text Available Ecoregions Terrestrial Biomes Protected Areas Climate Risk and Vulnerability: A Handbook for Southern Africa | 75 7.2. Non-climatic drivers of ecosystem change 7.2.1. Land-use change, habitat loss and fragmentation Land-use change and landscape... concentrations of endemic plant and animal species, but these mainly occur in areas that are most threatened by human activity. Diverse terrestrial ecosystems in the region include tropical and sub-tropical forests, deserts, savannas, grasslands, mangroves...
Transport phenomena in dissipative heavy-ion collisions: the one-body dissipation approach
International Nuclear Information System (INIS)
Feldmeier, H.
1987-01-01
The paper reviews dissipative collisions between two atomic nuclei, with the help of the classical description of Brownian movement and the Langevin equation. The 'one-body dissipation model' for dissipative heavy-ion collisions is discussed, and its predictions are compared with measured data. Special attention is paid to the non-equilibrium relation between friction and diffusion. (U.K.)
Tracking the attenuation and nonbreaking dissipation of swells using altimeters
Jiang, Haoyu; Stopa, Justin E.; Wang, He; Husson, Romain; Mouche, Alexis; Chapron, Bertrand; Chen, Ge
2016-02-01
A method for systematically tracking swells across oceanic basins is developed by taking advantage of high-quality data from space-borne altimeters and wave model output. The evolution of swells is observed over large distances based on 202 swell events with periods ranging from 12 to 18 s. An empirical attenuation rate of swell energy of about 4 × 10-7 m-1 is estimated using these observations, and the nonbreaking energy dissipation rates of swells far away from their generating areas are also estimated using a point source model. The resulting acceptance range of nonbreaking dissipation rates is -2.5 to 5.0 × 10-7 m-1, which corresponds to a dissipation e-folding scales of at least 2000 km for steep swells, to almost infinite for small-amplitude swells. These resulting rates are consistent with previous studies using in-situ and synthetic aperture radar (SAR) observations. The frequency dispersion and angular spreading effects during swell propagation are discussed by comparing the results with other studies, demonstrating that they are the two dominant processes for swell height attenuation, especially in the near field. The resulting dissipation rates from these observations can be used as a reference for ocean engineering and wave modeling, and for related studies such as air-sea and wind-wave-turbulence interactions.
Dissipation of the fungicide hexaconazole in oil palm plantation.
Maznah, Zainol; Halimah, Muhamad; Ismail, Sahid; Idris, Abu Seman
2015-12-01
Hexaconazole is a potential fungicide to be used in the oil palm plantation for controlling the basal stem root (BSR) disease caused by Ganoderma boninense. Therefore, the dissipation rate of hexaconazole in an oil palm agroecosystem under field conditions was studied. Two experimental plots were treated with hexaconazole at the recommended dosage of 4.5 g a.i. palm(-1) (active ingredient) and at double the recommended dosage (9.0 g a.i. palm(-1)), whilst one plot was untreated as control. The residue of hexaconazole was detected in soil samples in the range of 2.74 to 0.78 and 7.13 to 1.66 mg kg(-1) at the recommended and double recommended dosage plots, respectively. An initial relatively rapid dissipation rate of hexaconazole residues occurred but reduced with time. The dissipation of hexaconazole in soil was described using first-order kinetics with the value of coefficient regression (r (2) > 0.8). The results indicated that hexaconazole has moderate persistence in the soil and the half-life was found to be 69.3 and 86.6 days in the recommended and double recommended dosage plot, respectively. The results obtained highlight that downward movement of hexaconazole was led by preferential flow as shown in image analysis. It can be concluded that varying soil conditions, environmental factors, and pesticide chemical properties of hexaconazole has a significant impact on dissipation of hexaconazole in soil under humid conditions.
High-Density Quantum Sensing with Dissipative First Order Transitions.
Raghunandan, Meghana; Wrachtrup, Jörg; Weimer, Hendrik
2018-04-13
The sensing of external fields using quantum systems is a prime example of an emergent quantum technology. Generically, the sensitivity of a quantum sensor consisting of N independent particles is proportional to sqrt[N]. However, interactions invariably occurring at high densities lead to a breakdown of the assumption of independence between the particles, posing a severe challenge for quantum sensors operating at the nanoscale. Here, we show that interactions in quantum sensors can be transformed from a nuisance into an advantage when strong interactions trigger a dissipative phase transition in an open quantum system. We demonstrate this behavior by analyzing dissipative quantum sensors based upon nitrogen-vacancy defect centers in diamond. Using both a variational method and a numerical simulation of the master equation describing the open quantum many-body system, we establish the existence of a dissipative first order transition that can be used for quantum sensing. We investigate the properties of this phase transition for two- and three-dimensional setups, demonstrating that the transition can be observed using current experimental technology. Finally, we show that quantum sensors based on dissipative phase transitions are particularly robust against imperfections such as disorder or decoherence, with the sensitivity of the sensor not being limited by the T_{2} coherence time of the device. Our results can readily be applied to other applications in quantum sensing and quantum metrology where interactions are currently a limiting factor.
High-Density Quantum Sensing with Dissipative First Order Transitions
Raghunandan, Meghana; Wrachtrup, Jörg; Weimer, Hendrik
2018-04-01
The sensing of external fields using quantum systems is a prime example of an emergent quantum technology. Generically, the sensitivity of a quantum sensor consisting of N independent particles is proportional to √{N }. However, interactions invariably occurring at high densities lead to a breakdown of the assumption of independence between the particles, posing a severe challenge for quantum sensors operating at the nanoscale. Here, we show that interactions in quantum sensors can be transformed from a nuisance into an advantage when strong interactions trigger a dissipative phase transition in an open quantum system. We demonstrate this behavior by analyzing dissipative quantum sensors based upon nitrogen-vacancy defect centers in diamond. Using both a variational method and a numerical simulation of the master equation describing the open quantum many-body system, we establish the existence of a dissipative first order transition that can be used for quantum sensing. We investigate the properties of this phase transition for two- and three-dimensional setups, demonstrating that the transition can be observed using current experimental technology. Finally, we show that quantum sensors based on dissipative phase transitions are particularly robust against imperfections such as disorder or decoherence, with the sensitivity of the sensor not being limited by the T2 coherence time of the device. Our results can readily be applied to other applications in quantum sensing and quantum metrology where interactions are currently a limiting factor.
Dissipative Solitons that Cannot be Trapped
International Nuclear Information System (INIS)
Pardo, Rosa; Perez-Garcia, Victor M.
2006-01-01
We show that dissipative solitons in systems with high-order nonlinear dissipation cannot survive in the presence of trapping potentials of the rigid wall or asymptotically increasing type. Solitons in such systems can survive in the presence of a weak potential but only with energies out of the interval of existence of linear quantum mechanical stationary states
Quantum dissipation of a simple conservative system
International Nuclear Information System (INIS)
Ibeh, G. J.; Mshelia, E. D.
2014-01-01
A model of quantum dissipative system is presented. Here dissipation of energy is demonstrated as based on the coupling of a free translational motion of a centre of mass to a harmonic oscillator. The two-dimensional arrangement of two coupled particles of different masses is considered.
Dissipative electromagnetism from a nonequilibrium thermodynamics perspective
Jelic, A.; Hütter, M.; Öttinger, H.C.
2006-01-01
Dissipative effects in electromagnetism on macroscopic scales are examined by coarse-graining the microscopic Maxwell equations with respect to time. We illustrate a procedure to derive the dissipative effects on the macroscopic scale by using a Green-Kubo type expression in terms of the microscopic
Dissipation in nucleus-nucleus collisions
International Nuclear Information System (INIS)
Santanu Pal
1984-01-01
This paper deals with the mechanism of one- and two-body dissipations in nucleus-nucleus collisions. The average energy transferred to nuclear excitations is calculated using a time-dependent density matrix approach with lowest-order approximations. Considering the nuclei as Fermi gases, and using a gaussian-type NN interaction as the basic perturbation, simplified expressions are obtained for energy dissipations. These expressions are quite instructive to follow a number of interesting aspects of one- and two-body dissipations. It is theoretically observed that the memory time for the two-body dissipation is significantly smaller than that of one-body dissipation. A threshold-type dependence of the transferred energy on the relative velocity between the two nuclei is also observed. This threshold velocity is found to be related with the intrinsic nucleon kinetic energy for two-body dissipation and with the nuclear size for the one-body case. This observation further suggests that the total dissipated energy is shared between the two nuclei approximately in the ratio of their masses. The physical origin of these observations is also explained. Numerical calculations further illustrate some characteristic features of one- and two-body dissipations. (orig.)
On the stability of dissipative MHD equilibria
International Nuclear Information System (INIS)
Teichmann, J.
1979-04-01
The global stability of stationary equilibria of dissipative MHD is studied uisng the direct Liapunov method. Sufficient and necessary conditions for stability of the linearized Euler-Lagrangian system with the full dissipative operators are given. The case of the two-fluid isentropic flow is discussed. (orig.)
Analytical study of dissipative solitary waves
Energy Technology Data Exchange (ETDEWEB)
Dini, Fatemeh [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Emamzadeh, Mehdi Molaie [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Khorasani, Sina [School of Electrical Engineering, Sharif University of Technology, PO Box 11365-363, Tehran (Iran, Islamic Republic of); Bobin, Jean Louis [Universite Pierre et Marie Curie, Paris (France); Amrollahi, Reza [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Sodagar, Majid [School of Electrical Engineering, Sharif University of Technology, PO Box 11365-363, Tehran (Iran, Islamic Republic of); Khoshnegar, Milad [School of Electrical Engineering, Sharif University of Technology, PO Box 11365-363, Tehran (Iran, Islamic Republic of)
2008-02-15
In this paper, the analytical solution to a new class of nonlinear solitons is presented with cubic nonlinearity, subject to a dissipation term arising as a result of a first-order derivative with respect to time, in the weakly nonlinear regime. Exact solutions are found using the combination of the perturbation and Green's function methods up to the third order. We present an example and discuss the asymptotic behavior of the Green's function. The dissipative solitary equation is also studied in the phase space in the non-dissipative and dissipative forms. Bounded and unbounded solutions of this equation are characterized, yielding an energy conversation law for non-dissipative waves. Applications of the model include weakly nonlinear solutions of terahertz Josephson plasma waves in layered superconductors and ablative Rayleigh-Taylor instability.
Lagrangian descriptors in dissipative systems.
Junginger, Andrej; Hernandez, Rigoberto
2016-11-09
The reaction dynamics of time-dependent systems can be resolved through a recrossing-free dividing surface associated with the transition state trajectory-that is, the unique trajectory which is bound to the barrier region for all time in response to a given time-dependent potential. A general procedure based on the minimization of Lagrangian descriptors has recently been developed by Craven and Hernandez [Phys. Rev. Lett., 2015, 115, 148301] to construct this particular trajectory without requiring perturbative expansions relative to the naive transition state point at the top of the barrier. The extension of the method to account for dissipation in the equations of motion requires additional considerations established in this paper because the calculation of the Lagrangian descriptor involves the integration of trajectories in forward and backward time. The two contributions are in general very different because the friction term can act as a source (in backward time) or sink (in forward time) of energy, leading to the possibility that information about the phase space structure may be lost due to the dominance of only one of the terms. To compensate for this effect, we introduce a weighting scheme within the Lagrangian descriptor and demonstrate that for thermal Langevin dynamics it preserves the essential phase space structures, while they are lost in the nonweighted case.
Terrestrial and extraterrestrial fullerenes
Energy Technology Data Exchange (ETDEWEB)
Heymann, D.; Jenneskens, L.W.; Jehlicka, J; Koper, C.; Vlietstra, E. [Rice Univ, Houston, TX (United States). Dept. of Earth Science
2003-07-01
This paper reviews reports of occurrences of fullerenes in circumstellar media, interstellar media, meteorites, interplanetary dust particles (IDPs), lunar rocks, hard terrestrial rocks from Shunga (Russia), Sudbury (Canada) and Mitov (Czech Republic), coal, terrestrial sediments from the Cretaceous-Tertiary-Boundary and Pennian-Triassic-Boundary, fulgurite, ink sticks, dinosaur eggs, and a tree char. The occurrences are discussed in the context of known and postulated processes of fullerene formation, including the suggestion that some natural fullerenes might have formed from biological (algal) remains.
Foucault dissipation in a rolling cylinder: a webcam quantitative study
International Nuclear Information System (INIS)
Bonanno, A; Bozzo, G; Camarca, M; Sapia, P
2011-01-01
In this paper we present an experimental strategy to measure the micro power dissipation due to Foucault 'eddy' currents in a copper cylinder rolling on two parallel conductive rails in the presence of a magnetic field. Foucault power dissipation is obtained from kinematical measurements carried out by using a common PC webcam and video analysis done by means of software tools freely available within Windows operating system (Paint and Movie Maker). The proposed method allows us to experimentally discern the contribution to dissipation due to the velocity-independent rolling friction from that owed to the viscous-like friction emerging from complex electrodynamic interactions among eddy currents and the external magnetic field. In this way a microdissipation of some tens of μW is measured. The easily reproducible experimental setup, the simple implementation of data analysis and the discussion on various experimental approaches and strategies make the proposed activity highly significant for university undergraduates, since involved crucial skills can be efficiently strengthened.
Foucault dissipation in a rolling cylinder: a webcam quantitative study
Energy Technology Data Exchange (ETDEWEB)
Bonanno, A; Bozzo, G; Camarca, M; Sapia, P, E-mail: sapia@fis.unical.it [Physics Department, University of Calabria, I-87036 Rende, CS (Italy)
2011-03-15
In this paper we present an experimental strategy to measure the micro power dissipation due to Foucault 'eddy' currents in a copper cylinder rolling on two parallel conductive rails in the presence of a magnetic field. Foucault power dissipation is obtained from kinematical measurements carried out by using a common PC webcam and video analysis done by means of software tools freely available within Windows operating system (Paint and Movie Maker). The proposed method allows us to experimentally discern the contribution to dissipation due to the velocity-independent rolling friction from that owed to the viscous-like friction emerging from complex electrodynamic interactions among eddy currents and the external magnetic field. In this way a microdissipation of some tens of {mu}W is measured. The easily reproducible experimental setup, the simple implementation of data analysis and the discussion on various experimental approaches and strategies make the proposed activity highly significant for university undergraduates, since involved crucial skills can be efficiently strengthened.
Dissipation and leaching of 14C-monocrotophos in soil columns
International Nuclear Information System (INIS)
Vig, K.; Singh, D.K.; Agarwal, H.C.
2001-01-01
Dissipation and leaching of 14 C-monocrotophos was studied in the field. Two sets of PVC cylinders were used - one set received only 14 C monocrotophos and the other received 14 C-monocrotophos along with dimethoate, deltamethrin, endosulfan, cypermethrin and 1.06 mg unlabelled monocrotophos. Both setups showed a similar pattern of dissipation with a half-life of 277.2 days. Leaching of monocrotophos was observed into the 30cm soil layer. (author)
A generalized fluctuation-dissipation theorem for the one-dimensional diffusion process
International Nuclear Information System (INIS)
Okabe, Y.
1985-01-01
The [α,β,γ]-Langevin equation describes the time evolution of a real stationary process with T-positivity (reflection positivity) originating in the axiomatic quantum field theory. For this [α,β,γ]-Langevin equation a generalized fluctuation-dissipation theorem is proved. We shall obtain, as its application, a generalized fluctuation-dissipation theorem for the one-dimensional non-linear diffusion process, which presents one solution of Ryogo Kubo's problem in physics. (orig.)
Feist, B.; Bleacher, J. E.; Petro, N. E.; Niles, P. B.
2018-01-01
During the Apollo exploration of the lunar surface, thousands of still images, 16 mm videos, TV footage, samples, and surface experiments were captured and collected. In addition, observations and descriptions of what was observed was radioed to Mission Control as part of standard communications and subsequently transcribed. The archive of this material represents perhaps the best recorded set of geologic field campaigns and will serve as the example of how to conduct field work on other planetary bodies for decades to come. However, that archive of material exists in disparate locations and formats with varying levels of completeness, making it not easily cross-referenceable. While video and audio exist for the missions, it is not time synchronized, and images taken during the missions are not time or location tagged. Sample data, while robust, is not easily available in a context of where the samples were collected, their descriptions by the astronauts are not connected to them, or the video footage of their collection (if available). A more than five year undertaking to reconstruct and reconcile the Apollo 17 mission archive, from launch through splashdown, has generated an integrated record of the entire mission, resulting in searchable, synchronized image, voice, and video data, with geologic context provided at the time each sample was collected. Through www.apollo17.org the documentation of the field investigation conducted by the Apollo 17 crew is presented in chronologic sequence, with additional context provided by high-resolution Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images and a corresponding digital terrain model (DTM) of the Taurus-Littrow Valley.
Energy dissipation of rockfalls by coppice structures
Directory of Open Access Journals (Sweden)
G. Ciabocco
2009-06-01
Full Text Available The objective of this work is to develop elements to improve understanding of the behaviour of a coppice in relation to the phenomenon of falling boulders. The first section proposes an amendment to the equation for calculating the index which describes the probability of impact between a rock and plants in managed coppice forests. A study was carried out, using models to calculate the kinetic energy of a falling boulder along a slope considering the kinetic energy dissipated during the impact with the structure of forest plants managed by coppice. The output of the simulation models were then compared with the real dynamics of falling boulders in field tests using digital video.
It emerged from an analysis of the results of this comparison that a modification to the 1989 Gsteiger equation was required, in order to calculate the "Average Distance between Contacts" (ADC. To this purpose, the concept of "Structure of Interception", proposed in this paper, was developed, valid as a first approach for describing the differences in the spatial distribution of stems between coppice and forest. This study also aims to provide suggestions for forestry management, in order to maintain or increase the protective capacity of a coppice managed with conventional techniques for the area studied, modifying the dendrometric characteristics.
Solvable Family of Driven-Dissipative Many-Body Systems
Foss-Feig, Michael; Young, Jeremy T.; Albert, Victor V.; Gorshkov, Alexey V.; Maghrebi, Mohammad F.
2017-11-01
Exactly solvable models have played an important role in establishing the sophisticated modern understanding of equilibrium many-body physics. Conversely, the relative scarcity of solutions for nonequilibrium models greatly limits our understanding of systems away from thermal equilibrium. We study a family of nonequilibrium models, some of which can be viewed as dissipative analogues of the transverse-field Ising model, in that an effectively classical Hamiltonian is frustrated by dissipative processes that drive the system toward states that do not commute with the Hamiltonian. Surprisingly, a broad and experimentally relevant subset of these models can be solved efficiently. We leverage these solutions to compute the effects of decoherence on a canonical trapped-ion-based quantum computation architecture, and to prove a no-go theorem on steady-state phase transitions in a many-body model that can be realized naturally with Rydberg atoms or trapped ions.
Electrostatic shock structures in dissipative multi-ion dusty plasmas
Elkamash, I. S.; Kourakis, I.
2018-06-01
A comprehensive analytical model is introduced for shock excitations in dusty bi-ion plasma mixtures, taking into account collisionality and kinematic (fluid) viscosity. A multicomponent plasma configuration is considered, consisting of positive ions, negative ions, electrons, and a massive charged component in the background (dust). The ionic dynamical scale is focused upon; thus, electrons are assumed to be thermalized, while the dust is stationary. A dissipative hybrid Korteweg-de Vries/Burgers equation is derived. An analytical solution is obtained, in the form of a shock structure (a step-shaped function for the electrostatic potential, or an electric field pulse) whose maximum amplitude in the far downstream region decays in time. The effect of relevant plasma configuration parameters, in addition to dissipation, is investigated. Our work extends earlier studies of ion-acoustic type shock waves in pure (two-component) bi-ion plasma mixtures.
Dissipative structures and biological rhythms
Goldbeter, Albert
2017-10-01
Sustained oscillations abound in biological systems. They occur at all levels of biological organization over a wide range of periods, from a fraction of a second to years, and with a variety of underlying mechanisms. They control major physiological functions, and their dysfunction is associated with a variety of physiological disorders. The goal of this review is (i) to give an overview of the main rhythms observed at the cellular and supracellular levels, (ii) to briefly describe how the study of biological rhythms unfolded in the course of time, in parallel with studies on chemical oscillations, (iii) to present the major roles of biological rhythms in the control of physiological functions, and (iv) the pathologies associated with the alteration, disappearance, or spurious occurrence of biological rhythms. Two tables present the main examples of cellular and supracellular rhythms ordered according to their period, and their role in physiology and pathophysiology. Among the rhythms discussed are neural and cardiac rhythms, metabolic oscillations such as those occurring in glycolysis in yeast, intracellular Ca++ oscillations, cyclic AMP oscillations in Dictyostelium amoebae, the segmentation clock that controls somitogenesis, pulsatile hormone secretion, circadian rhythms which occur in all eukaryotes and some bacteria with a period close to 24 h, the oscillatory dynamics of the enzymatic network driving the cell cycle, and oscillations in transcription factors such as NF-ΚB and tumor suppressors such as p53. Ilya Prigogine's concept of dissipative structures applies to temporal oscillations and allows us to unify within a common framework the various rhythms observed at different levels of biological organization, regardless of their period and underlying mechanism.
Heldmann, Jennifer L.; Colaprete, Anthony; Elphic, Richard C.; Lim, Darlene; Deans, Matthew; Cook, Amanda; Roush, Ted; Skok, J. R.; Button, Nicole E.; Karunatillake, S.; Stoker, Carol; Marquez, Jessica J.; Shirley, Mark; Kobayashi, Linda; Lees, David; Bresina, John; Hunt, Rusty
2016-08-01
The Mojave Volatiles Prospector (MVP) project is a science-driven field program with the goal of producing critical knowledge for conducting robotic exploration of the Moon. Specifically, MVP focuses on studying a lunar mission analog to characterize the form and distribution of lunar volatiles. Although lunar volatiles are known to be present near the poles of the Moon, the three dimensional distribution and physical characteristics of lunar polar volatiles are largely unknown. A landed mission with the ability to traverse the lunar surface is thus required to characterize the spatial distribution of lunar polar volatiles. NASA's Resource Prospector (RP) mission is a lunar polar rover mission that will operate primarily in sunlit regions near a lunar pole with near-real time operations to characterize the vertical and horizontal distribution of volatiles. The MVP project was conducted as a field campaign relevant to the RP lunar mission to provide science, payload, and operational lessons learned to the development of a real-time, short-duration lunar polar volatiles prospecting mission. To achieve these goals, the MVP project conducted a simulated lunar rover mission to investigate the composition and distribution of surface and subsurface volatiles in a natural environment with an unknown volatile distribution within the Mojave Desert, improving our understanding of how to find, characterize, and access volatiles on the Moon.
Dissipative chaos in semiconductor superlattices
Directory of Open Access Journals (Sweden)
F. Moghadam
2008-03-01
Full Text Available In this paper the motion of electron in a miniband of a semiconductor superlattice (SSL under the influence of external electric and magnetic fields is investigated. The electric field is applied in a direction perpendicular to the layers of the semiconductor superlattice, and the magnetic field is applied in different direction Numerical calculations show conditions led to the possibility of chaotic behaviors.
Histories of terrestrial planets
International Nuclear Information System (INIS)
Benes, K.
1981-01-01
The uneven historical development of terrestrial planets - Mercury, Venus, Earth, Moon and Mars - is probably due to the differences in their size, weight and rotational dynamics in association with the internal planet structure, their distance from the Sun, etc. A systematic study of extraterrestrial planets showed that the time span of internal activity was not the same for all bodies. It is assumed that the initial history of all terrestrial planets was marked with catastrophic events connected with the overall dynamic development of the solar system. In view of the fact that the cores of small terrestrial bodies cooled quicker, their geological development almost stagnated after two or three thousand million years. This is what probably happened to the Mercury and the Moon as well as the Mars. Therefore, traces of previous catastrophic events were preserved on the surface of the planets. On the other hand, the Earth is the most metamorphosed terrestrial planet and compared to the other planets appears to be atypical. Its biosphere is significantly developed as well as the other shell components, its hydrosphere and atmosphere, and its crust is considerably differentiated. (J.P.)
Righter, K; O'Brien, D P
2011-11-29
Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.
Radionuclides in terrestrial ecosystems
International Nuclear Information System (INIS)
Bocock, K.L.
1981-01-01
This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)
Low moduli elastomers with low viscous dissipation
DEFF Research Database (Denmark)
Bejenariu, Anca Gabriela; Yu, Liyun; Skov, Anne Ladegaard
2012-01-01
A controlled reaction schema for addition curing silicones leads to both significantly lower elastic modulus and lower viscous dissipation than for the chemically identical network prepared by the traditional reaction schema....
Dissipation effects in mechanics and thermodynamics
Güémez, J.; Fiolhais, M.
2016-07-01
With the discussion of three examples, we aim at clarifying the concept of energy transfer associated with dissipation in mechanics and in thermodynamics. The dissipation effects due to dissipative forces, such as the friction force between solids or the drag force in motions in fluids, lead to an internal energy increase of the system and/or to heat transfer to the surroundings. This heat flow is consistent with the second law, which states that the entropy of the universe should increase when those forces are present because of the irreversibility always associated with their actions. As far as mechanics is concerned, the effects of the dissipative forces are included in Newton’s equations as impulses and pseudo-works.
Phenomenological approaches of dissipative heavy ion collisions
International Nuclear Information System (INIS)
Ngo, C.
1983-09-01
These lectures describe the properties of dissipative heavy ion collisions observed in low bombarding energy heavy ion reactions. These dissipative collisions are of two different types: fusion and deep inelastic reactions. Their main experimental properties are described on selected examples. It is shown how it is possible to give a simple interpretation to the data. A large number of phenomenological models have been developped to understand dissipative heavy ion collisions. The most important are those describing the collision by classical mechanics and friction forces, the diffusion models, and transport theories which merge both preceding approaches. A special emphasis has been done on two phenomena observed in dissipative heavy ion collisions: charge equilibratium for which we can show the existence of quantum fluctuations, and fast fission which appears as an intermediate mechanism between deep inelastic reactions and compound nucleus formation [fr
Observed eddy dissipation in the Agulhas Current
CSIR Research Space (South Africa)
Braby, L
2016-08-01
Full Text Available (negative) velocity anomalies propagate downstream in the Agulhas Current at 44 km/d (23 km/d). Many models are unable to represent these eddy dissipation processes, affecting our understanding of the Agulhas Current....
Minimum dissipative relaxed states in toroidal plasmas
Indian Academy of Sciences (India)
organised equi- librium in RFP and tokamak by a deterministic approach to incompressible dissipative magnetohydrodynamics. In an earlier work Kondoh [8] formulated an energy principle including the edge plasma effects for a slightly resistive MHD ...
Dudkin, Fedir; Korepanov, Valery; Dudkin, Denis; Pilipenko, Vyacheslav; Pronenko, Vira; Klimov, Stanislav
2015-07-01
The power line emission (PLE) 50/60 Hz and the Schumann resonance (SR) harmonics were detected by the use of a compact electrical field sensor of length 0.42 m during microsatellite Chibis-M mission in years 2012-2014. The initial orbit of Chibis-M has altitude 500 km and inclination 52°. We present the space distribution of PLE and its connections with the possible overhead power lines. PLE has been recorded both in the shade and sunlit parts of the orbits as opposed to SR which have been recorded only in the nightside of the Earth. The cases of an extra long distance of PLE propagation in the Earth's ionosphere and increased value of SR Q factor have been also observed. These results should stimulate the ionosphere model refinement for ultralow frequency and extremely low frequency electromagnetic wave propagation as well as a study on new possibility of the ionosphere diagnostics.
Energy dissipation in multifrequency atomic force microscopy
Directory of Open Access Journals (Sweden)
Valentina Pukhova
2014-04-01
Full Text Available The instantaneous displacement, velocity and acceleration of a cantilever tip impacting onto a graphite surface are reconstructed. The total dissipated energy and the dissipated energy per cycle of each excited flexural mode during the tip interaction is retrieved. The tip dynamics evolution is studied by wavelet analysis techniques that have general relevance for multi-mode atomic force microscopy, in a regime where few cantilever oscillation cycles characterize the tip–sample interaction.
Hamiltonian description and quantization of dissipative systems
Enz, Charles P.
1994-09-01
Dissipative systems are described by a Hamiltonian, combined with a “dynamical matrix” which generalizes the simplectic form of the equations of motion. Criteria for dissipation are given and the examples of a particle with friction and of the Lotka-Volterra model are presented. Quantization is first introduced by translating generalized Poisson brackets into commutators and anticommutators. Then a generalized Schrödinger equation expressed by a dynamical matrix is constructed and discussed.
Drift bifurcation detection for dissipative solitons
International Nuclear Information System (INIS)
Liehr, A W; Boedeker, H U; Roettger, M C; Frank, T D; Friedrich, R; Purwins, H-G
2003-01-01
We report on the experimental detection of a drift bifurcation for dissipative solitons, which we observe in the form of current filaments in a planar semiconductor-gas-discharge system. By introducing a new stochastic data analysis technique we find that due to a change of system parameters the dissipative solitons undergo a transition from purely noise-driven objects with Brownian motion to particles with a dynamically stabilized finite velocity
The early evolution of the atmospheres of terrestrial planets
Raulin, François; Muller, Christian; Nixon, Conor; Astrophysics and Space Science Proceedings : Volume 35
2013-01-01
“The Early Evolution of the Atmospheres of Terrestrial Planets” presents the main processes participating in the atmospheric evolution of terrestrial planets. A group of experts in the different fields provide an update of our current knowledge on this topic. Several papers in this book discuss the key role of nitrogen in the atmospheric evolution of terrestrial planets. The earliest setting and evolution of planetary atmospheres of terrestrial planets is directly associated with accretion, chemical differentiation, outgassing, stochastic impacts, and extremely high energy fluxes from their host stars. This book provides an overview of the present knowledge of the initial atmospheric composition of the terrestrial planets. Additionally it includes some papers about the current exoplanet discoveries and provides additional clues to our understanding of Earth’s transition from a hot accretionary phase into a habitable world. All papers included were reviewed by experts in their respective fields. We are ...
Study of dissipation in superconductors at high frequency regime
International Nuclear Information System (INIS)
Vallet, Christophe
1994-01-01
This thesis is devoted to the study of the Joule effect dissipation occurring in superconducting accelerating cavities. Two mechanisms of dissipation are presented: the first concerns the magnetic flux present around the cryostat and trapped by the (Niobium) superconducting cavity during a temperature descent; a theoretical and experimental study allow the evaluation of the percentage of flux which rests trapped and its contribution to the dissipation. Improving the magnetic shielding leads to a remnant field of the order of several milli-Gauss and the surface resistance drops from 25 nΩ to 4.2 nΩ (with a few other modifications). The second mechanism is related to the polycrystalline structure of the superconductor. A theoretical study evaluates this contribution to about 3 nΩ. A complex process of recrystallization is needed in order to overcome this effect. Using an electron beam at low energy might help in reaching this goal and thus observing surface resistance values smaller than ever obtained. (author) [fr
Constraining planetary migration and tidal dissipation with coeval hot Jupiters
O'Connor, Christopher E.; Hansen, Bradley M. S.
2018-06-01
We investigate the constraints on the formation of, and tidal dissipation processes in, hot Jupiters (HJs) that can be inferred based on reliable knowledge of the age of a system or population. Particular attention is paid to the role of young systems (such as those in open clusters or star-forming regions) in such studies. For an ensemble of coeval HJ (or proto-HJ) systems, we quantify the effect of age on the distribution of orbital eccentricities with respect to orbital periods as well as the location of the observed `pile-up' feature. We expect the effects of pre-main-sequence stellar evolution to be important only if a substantial fraction of HJs approach their current orbits early in protostellar contraction (ages ≲ 10 Myr). Application to the HJs presently known in the cluster M 67 yields constraints on the dissipation roughly consistent with those gleaned from planets in the field; for those in the Hyades and Praesepe, our results suggest a higher degree of dissipation at early times than that inferred from other populations.
Energy spectrum, dissipation, and spatial structures in reduced Hall magnetohydrodynamic
Energy Technology Data Exchange (ETDEWEB)
Martin, L. N.; Dmitruk, P. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Gomez, D. O. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Instituto de Astronomia y Fisica del Espacio, CONICET, Buenos Aires (Argentina)
2012-05-15
We analyze the effect of the Hall term in the magnetohydrodynamic turbulence under a strong externally supported magnetic field, seeing how this changes the energy cascade, the characteristic scales of the flow, and the dynamics of global magnitudes, with particular interest in the dissipation. Numerical simulations of freely evolving three-dimensional reduced magnetohydrodynamics are performed, for different values of the Hall parameter (the ratio of the ion skin depth to the macroscopic scale of the turbulence) controlling the impact of the Hall term. The Hall effect modifies the transfer of energy across scales, slowing down the transfer of energy from the large scales up to the Hall scale (ion skin depth) and carrying faster the energy from the Hall scale to smaller scales. The final outcome is an effective shift of the dissipation scale to larger scales but also a development of smaller scales. Current sheets (fundamental structures for energy dissipation) are affected in two ways by increasing the Hall effect, with a widening but at the same time generating an internal structure within them. In the case where the Hall term is sufficiently intense, the current sheet is fully delocalized. The effect appears to reduce impulsive effects in the flow, making it less intermittent.
International Nuclear Information System (INIS)
Anon.
1993-01-01
A working group at a Canada/USA symposium on climate change and the Arctic identified major concerns and issues related to terrestrial resources. The group examined the need for, and the means of, involving resource managers and users at local and territorial levels in the process of identifying and examining the impacts and consequences of climatic change. Climatic change will be important to the Arctic because of the magnitude of the change projected for northern latitudes; the apparent sensitivity of its terrestrial ecosystems, natural resources, and human support systems; and the dependence of the social, cultural, and economic welfare of Arctic communities, businesses, and industries on the health and quality of their environment. Impacts of climatic change on the physical, biological, and associated socio-economic environment are outlined. Gaps in knowledge needed to quantify these impacts are listed along with their relationships with resource management. Finally, potential actions for response and adaptation are presented
Phytopharmacology of Tribulus terrestris.
Shahid, M; Riaz, M; Talpur, M M A; Pirzada, T
2016-01-01
Tribulus terrestris is an annual herb which belongs to the Zygophyllaceae family. This plant has been used in traditional medicine for the treatment of various diseases for hundreds of decades. The main active phytoconstituents of this plant include flavonoids, alkaloids, saponins, lignin, amides, and glycosides. The plant parts have different pharmacological activities including aphrodisiac, antiinflammatory, antimicrobial and antioxidant potential. T. terrestris is most often used for infertility and loss of libido. It has potential application as immunomodulatory, hepatoprotective, hypolipidemic, anthelmintic and anticarcinogenic activities. The aim of the present article is to create a database for further investigation of the phytopharmacological properties of this plant to promote research. This study will definitely help to confirm its traditional use along with its value-added utility, eventually leading to higher revenues from the plant.
Terrestrial plant methane production
DEFF Research Database (Denmark)
Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.
We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....
Wave Dissipation on Low- to Super-Energy Coral Reefs
Harris, D. L.
2016-02-01
Coral reefs are valuable, complex and bio-diverse ecosystems and are also known to be one of the most effective barriers to swell events in coastal environments. Previous research has found coral reefs to be remarkably efficient in removing most of the wave energy during the initial breaking and transformation on the reef flats. The rate of dissipation is so rapid that coral reefs have been referred to as rougher than any known coastal barrier. The dissipation of wave energy across reef flats is crucial in maintaining the relatively low-energy conditions in the back reef and lagoonal environments providing vital protection to adjacent beach or coastal regions from cyclone and storm events. A shift in the regulation of wave energy by reef flats could have catastrophic consequences ecologically, socially, and economically. This study examined the dissipation of wave energy during two swell events in Tahiti and Moorea, French Polyesia. Field sites were chosen in varying degrees of exposure and geomorphology from low-energy protected sites (Tiahura, Moorea) to super-energy sites (Teahupo'o, Tahiti). Waves were measured during two moderate to large swell events in cross reef transects using short-term high-resolution pressure transducers. Wave conditions were found to be similar in all back reef locations despite the very different wave exposure at each reef site. However, wave conditions on the reef flats were different and mirrored the variation in wave exposure with depth over the reef flat the primary regulator of reef flat wave height. These results indicate that coral reef flats evolve morphodynamically with the wave climate, which creates coral reef geomorphologies capable of dissipating wave energy that results in similar back reef wave conditions regardless of the offshore wave climate.
Decay of Kadomtsev-Petviashvili lumps in dissipative media
Clarke, S.; Gorshkov, K.; Grimshaw, R.; Stepanyants, Y.
2018-03-01
The decay of Kadomtsev-Petviashvili lumps is considered for a few typical dissipations-Rayleigh dissipation, Reynolds dissipation, Landau damping, Chezy bottom friction, viscous dissipation in the laminar boundary layer, and radiative losses caused by large-scale dispersion. It is shown that the straight-line motion of lumps is unstable under the influence of dissipation. The lump trajectories are calculated for two most typical models of dissipation-the Rayleigh and Reynolds dissipations. A comparison of analytical results obtained within the framework of asymptotic theory with the direct numerical calculations of the Kadomtsev-Petviashvili equation is presented. Good agreement between the theoretical and numerical results is obtained.
Transient chaotic transport in dissipative drift motion
Energy Technology Data Exchange (ETDEWEB)
Oyarzabal, R.S. [Pós-Graduação em Ciências/Física, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Szezech, J.D. [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Batista, A.M., E-mail: antoniomarcosbatista@gmail.com [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Souza, S.L.T. de [Departamento de Física e Matemática, Universidade Federal de São João del Rei, 36420-000, Ouro Branco, MG (Brazil); Caldas, I.L. [Instituto de Física, Universidade de São Paulo, 05315-970, São Paulo, SP (Brazil); Viana, R.L. [Departamento de Física, Universidade Federal do Paraná, 81531-990, Curitiba, PR (Brazil); Sanjuán, M.A.F. [Departamento de Física, Universidad Rey Juan Carlos, Tulipán s/n, 28933 Móstoles, Madrid (Spain)
2016-04-22
Highlights: • We consider a situation for which a chaotic transient is present in the dynamics of the two-wave model with damping. • The damping in plasma models can be a way for study a realistic behavior of confinement due the collisional effect. • The escape time as a function of the damping obey a power-law scaling. • We have made a qualitative transport analysis with a simple model that can be useful for more complete models. • We have shown that the pattern of the basin of attraction depends on the damping parameter. - Abstract: We investigate chaotic particle transport in magnetised plasmas with two electrostatic drift waves. Considering dissipation in the drift motion, we verify that the removed KAM surfaces originate periodic attractors with their corresponding basins of attraction. We show that the properties of the basins depend on the dissipation and the space-averaged escape time decays exponentially when the dissipation increases. We find positive finite time Lyapunov exponents in dissipative drift motion, consequently the trajectories exhibit transient chaotic transport. These features indicate how the transient plasma transport depends on the dissipation.
A dissipative model of plasma equilibrium in toroidal systems
International Nuclear Information System (INIS)
Wobig, H.
1985-10-01
In order to describe a steady-state plasma equilibrium in tokamaks, stellarators or other non-axisymmetric configurations, the model of ideal MHD with isotropic plasma pressure is widely used. The ideal MHD - model of a toroidal plasma equilibrium requires the existence of closed magnetic surfaces. Several numerical codes have been developed in the past to solve the three-dimensional equilibrium problem, but so far no existence theorem for a solution has been proved. Another difficulty is the formation of magnetic islands and field line ergodisation, which can only be described in terms of ideal MHD if the plasma pressure is constant in the ergodic region. In order to describe the formation of magnetic islands and ergodisation of surfaces properly, additional dissipative terms have to be incorporated to allow decoupling of the plasma and magnetic field. In a collisional plasma viscosity and inelastic collisions introduce such dissipative processes. In the model used a friction term proportional to the velocity v vector of the plasma is included. Such a term originates from charge exchange interaction of the plasma with a nuetral background. With these modifications, the equilibrium problem reduces to a set of quasilinear elliptic equations for the pressure, the electric potential and the magnetic field. The paper deals with an existence theorem based on the Fixed - Point method of Schauder. It can be shown that a self-consistent and unique equilibrium exists if the friction term is large and the plasma pressure is sufficiently low. The essential role of the dissipative terms is to remove the singularities of the ideal MHD model on rational magnetic surfaces. The problem has a strong similarity to Benard cell convection, and consequently similar behaviour such as bifurcation and exchange of stability are expected. (orig./GG)
Dynamics of quasi-stable dissipative systems
Chueshov, Igor
2015-01-01
This book is devoted to background material and recently developed mathematical methods in the study of infinite-dimensional dissipative systems. The theory of such systems is motivated by the long-term goal to establish rigorous mathematical models for turbulent and chaotic phenomena. The aim here is to offer general methods and abstract results pertaining to fundamental dynamical systems properties related to dissipative long-time behavior. The book systematically presents, develops and uses the quasi-stability method while substantially extending it by including for consideration new classes of models and PDE systems arising in Continuum Mechanics. The book can be used as a textbook in dissipative dynamics at the graduate level. Igor Chueshov is a Professor of Mathematics at Karazin Kharkov National University in Kharkov, Ukraine.
Sudden viscous dissipation in compressing plasma turbulence
Davidovits, Seth; Fisch, Nathaniel
2015-11-01
Compression of a turbulent plasma or fluid can cause amplification of the turbulent kinetic energy, if the compression is fast compared to the turnover and viscous dissipation times of the turbulent eddies. The consideration of compressing turbulent flows in inviscid fluids has been motivated by the suggestion that amplification of turbulent kinetic energy occurred on experiments at the Weizmann Institute of Science Z-Pinch. We demonstrate a sudden viscous dissipation mechanism whereby this amplified turbulent kinetic energy is rapidly converted into thermal energy, which further increases the temperature, feeding back to further enhance the dissipation. Application of this mechanism in compression experiments may be advantageous, if the plasma can be kept comparatively cold during much of the compression, reducing radiation and conduction losses, until the plasma suddenly becomes hot. This work was supported by DOE through contract 67350-9960 (Prime # DOE DE-NA0001836) and by the DTRA.
Effect of dissipation on dynamical fusion thresholds
International Nuclear Information System (INIS)
Sierk, A.J.
1986-01-01
The existence of dynamical thresholds to fusion in heavy nuclei (A greater than or equal to 200) due to the nature of the potential-energy surface is shown. These thresholds exist even in the absence of dissipative forces, due to the coupling between the various collective deformation degrees of freedom. Using a macroscopic model of nuclear shape dynamics, It is shown how three different suggested dissipation mechanisms increase by varying amounts the excitation energy over the one-dimensional barrier required to cause compound-nucleus formation. The recently introduced surface-plus-window dissipation may give a reasonable representation of experimental data on fusion thresholds, in addition to properly describing fission-fragment kinetic energies and isoscalar giant multipole widths. Scaling of threshold results to asymmetric systems is discussed. 48 refs., 10 figs
Optimizing the microstructure of dissipative materials
DEFF Research Database (Denmark)
Andreassen, Erik; Lazarov, Boyan Stefanov; Jensen, Jakob Søndergaard
the material’s loss factor, however, only for large wave lengths (small wave numbers) and constant material parameters (Andreasen et al., 2012). An alternative way to determine the material’s loss factor is to consider the material’s band diagram (Sigalas and Economou, 1992), from which the loss factor can......The aim of this work is to present a method to design material microstructures with high dissipation using topology optimization. In order to compute the macroscopic energy dissipation in periodic structures, we focus both on capturing the physical dissipation mechanism and to find the effective...... from experimental results in (Schaedler, 2011), where a highly energy absorbing material, constructed from structural elements with a small cross sectional area but large area moment of inertia, is presented. Furthermore, the applicability of multiscale finite element methods (Efendiev, 2009...
Induced waveform transitions of dissipative solitons
Kochetov, Bogdan A.; Tuz, Vladimir R.
2018-01-01
The effect of an externally applied force upon the dynamics of dissipative solitons is analyzed in the framework of the one-dimensional cubic-quintic complex Ginzburg-Landau equation supplemented by a potential term with an explicit coordinate dependence. The potential accounts for the external force manipulations and consists of three symmetrically arranged potential wells whose depth varies along the longitudinal coordinate. It is found out that under an influence of such potential a transition between different soliton waveforms coexisting under the same physical conditions can be achieved. A low-dimensional phase-space analysis is applied in order to demonstrate that by only changing the potential profile, transitions between different soliton waveforms can be performed in a controllable way. In particular, it is shown that by means of a selected potential, stationary dissipative soliton can be transformed into another stationary soliton as well as into periodic, quasi-periodic, and chaotic spatiotemporal dissipative structures.
Dissipative Continuous Spontaneous Localization (CSL) model.
Smirne, Andrea; Bassi, Angelo
2015-08-05
Collapse models explain the absence of quantum superpositions at the macroscopic scale, while giving practically the same predictions as quantum mechanics for microscopic systems. The Continuous Spontaneous Localization (CSL) model is the most refined and studied among collapse models. A well-known problem of this model, and of similar ones, is the steady and unlimited increase of the energy induced by the collapse noise. Here we present the dissipative version of the CSL model, which guarantees a finite energy during the entire system's evolution, thus making a crucial step toward a realistic energy-conserving collapse model. This is achieved by introducing a non-linear stochastic modification of the Schrödinger equation, which represents the action of a dissipative finite-temperature collapse noise. The possibility to introduce dissipation within collapse models in a consistent way will have relevant impact on the experimental investigations of the CSL model, and therefore also on the testability of the quantum superposition principle.
Microscopic theory of one-body dissipation
International Nuclear Information System (INIS)
Koonin, S.E.; Randrup, J.; Hatch, R.; Kolomietz, V.
1977-01-01
A microscopic theory is developed for nuclear collective motion in the limit of a long nuclear mean-free path. Linear response techniques are applied to an independent particle model and expressions for the collective kinetic energy and rate of energy dissipation are obtained. For leptodermous systems, these quantities are characterized by mass and dissipation kernels coupling the velocities at different points on the nuclear surface. In a classical treatment, the kernels are given in terms of nucleon trajectories within the nuclear shape. In a quantal treatment, the dissipation kernel is related to the nuclear Green function. The spatial and thermal properties of the kernels are investigated. Corrections for the diffuseness of the potential and shell effects are also discussed. (Auth.)
Forces and energy dissipation in inhomogeneous non-equilibrium superconductors
International Nuclear Information System (INIS)
Poluehktov, Yu.M.; Slezov, V.V.
1987-01-01
The phenomenological theory of volume forces and dissipation processes in inhomogeneous non-equilibrium superconductors near temperature transition from the normal to superconducting state is constructed. The approach is based on application of dynamic equations of superconductivity formulated on the basis of the Lagrangian formalism. These equations are generalized the Ginzburg-Landau theory in the nonstationary non-equilibrium case for ''foul'' superconductors. The value estimations of volume forces arising in inhomogeneities during relaxation of an order parameter and when the electrical field is penetrated into the superconductor, are given
Surface erosion issues and analysis for dissipative divertors
International Nuclear Information System (INIS)
Brooks, J.N.; Ruzic, D.N.; Hayden, D.B.; Turkot, R.B. Jr.
1994-05-01
Erosion/redeposition is examined for the sidewall of a dissipative divertor using coupled impurity transport, charge exchange, and sputtering codes, applied to a plasma solution for the ITER design. A key issue for this regime is possible runaway self-sputtering, due to the effect of a low boundary density and nearly parallel field geometry on redeposition parameters. Net erosion rates, assuming finite self-sputtering, vary with wall location, boundary conditions, and plasma solution, and are roughly of the following order: 200--2000 angstrom/s for beryllium, 10--100 angstrom/s for vanadium, and 0.3--3 angstrom/s for tungsten
Comparative Climatology of Terrestrial Planets
Mackwell, Stephen J.; Simon-Miller, Amy A.; Harder, Jerald W.; Bullock, Mark A.
to a future volume. Our authors have taken on the task to look at climate on the terrestrial planets in the broadest sense possible — by comparing the atmospheric processes at work on the four terrestrial bodies, Earth, Venus, Mars, and Titan (Titan is included because it hosts many of the common processes), and on terrestrial planets around other stars. These processes include the interactions of shortwave and thermal radiation with the atmosphere, condensation and vaporization of volatiles, atmospheric dynamics, chemistry and aerosol formation, and the role of the surface and interior in the long-term evolution of climate. Chapters herein compare the scientific questions, analysis methods, numerical models, and spacecraft remote sensing experiments of Earth and the other terrestrial planets, emphasizing the underlying commonality of physical processes. We look to the future by identifying objectives for ongoing research and new missions. Through these pages we challenge practicing planetary scientists, and most importantly new students of any age, to find pathways and synergies for advancing the field. In Part I, Foundations, we introduce the fundamental physics of climate on terrestrial planets. Starting with the best studied planet by far, Earth, the first chapters discuss what is known and what is not known about the atmospheres and climates of the terrestrial planets of the solar system and beyond. In Part II, Greenhouse Effect and Atmospheric Dynamics, we focus on the processes that govern atmospheric motion and the role that general circulation models play in our current understanding. In Part III, Clouds and Hazes, we provide an in-depth look at the many effects of clouds and aerosols on planetary climate. Although this is a vigorous area of research in the Earth sciences, and very strongly influences climate modeling, the important role that aerosols and clouds play in the climate of all planets is not yet well constrained. This section is intended to
Cancer is an adaptation that selects in animals against energy dissipation.
Muller, Anthonie W J
2017-07-01
As cancer usually follows reproduction, it is generally assumed that cancer does not select. Graham has however argued that juvenile cancer, which precedes reproduction, could during evolution have implemented a "cancer selection" that resulted in novel traits that suppress this juvenile cancer; an example is protection against UV sunlight-induced cancer, required for the emergence of terrestrial animals from the sea. We modify the cancer selection mechanism to the posited "cancer adaptation" mechanism, in which juvenile mortality is enhanced through the diminished care received by juveniles from their (grand) parents when these suffer from cancer in old age. Moreover, it is posited that the cancer adaptation selects against germline "dissipative genes", genes that result in enhanced free energy dissipation. Cancer's progression is interpreted as a cascade at increasing scale of repeated amplification of energy dissipation, a cascade involving heat shock, the Warburg effect, the cytokine IL-6, tumours, and hypermetabolism. Disturbance of any physiological process must enhance energy dissipation if the animal remains functioning normally, what explains multicausality, why "everything gives you cancer". The hypothesis thus comprises two newly invoked partial processes-diminished (grand) parental care and dissipation amplification-and results in a "selection against enhanced energy dissipation" which gives during evolution the benefit of energy conservation. Due to this benefit, cancer would essentially be an adaptation, and not a genetic disease, as assumed in the "somatic mutation theory". Cancer by somatic mutations is only a side process. The cancer adaptation hypothesis is substantiated by (1) cancer's extancy, (2) the failure of the somatic mutation theory, (3) cancer's initiation by a high temperature, (4) the interpretation of cancer's progression as a thermal process, and (5) the interpretation of tumours as organs that implement thermogenesis. The hypothesis
Analysis of phononic bandgap structures with dissipation
DEFF Research Database (Denmark)
Andreassen, Erik; Jensen, Jakob Søndergaard
2013-01-01
and longer wavelengths, we show that the two formulations produce nearly identical results in terms of propagation constant and wave decay. We use the k(ω)-formulation to compute loss factors with dissipative bandgap materials for steady-state wave propagation and create simplified diagrams that unify...... the spatial loss factor from dissipative and bandgap effects. Additionally, we demonstrate the applicability of the k(ω)-formulation for the computation of the band diagram for viscoelastic composites and compare the computed loss factors for low frequency wave propagation to existing results based on quasi...
New derivation of relativistic dissipative fluid dynamics
International Nuclear Information System (INIS)
Jaiswal, Amaresh; Bhalerao, Rajeev S.; Pal, Subrata
2012-01-01
Relativistic dissipative hydrodynamics has been quite successful in explaining the spectra and azimuthal anisotropy of particles produced in heavy-ion collisions at the RHIC and recently at the LHC. The first-order dissipative fluid dynamics or the relativistic Navier-Stokes (NS) theory involves parabolic differential equations and suffers from a causality and instability. The second-order or Israel-Stewart (IS) theory with its hyperbolic equations restores causality but may not guarantee stability. The correct formulation of relativistic viscous fluid dynamics is far from settled and is under intense investigation
Quantum dissipation from power-law memory
International Nuclear Information System (INIS)
Tarasov, Vasily E.
2012-01-01
A new quantum dissipation model based on memory mechanism is suggested. Dynamics of open and closed quantum systems with power-law memory is considered. The processes with power-law memory are described by using integration and differentiation of non-integer orders, by methods of fractional calculus. An example of quantum oscillator with linear friction and power-law memory is considered. - Highlights: ► A new quantum dissipation model based on memory mechanism is suggested. ► The generalization of Lindblad equation is considered. ► An exact solution of generalized Lindblad equation for quantum oscillator with linear friction and power-law memory is derived.
Mechanical energy dissipation in natural ceramic composites.
Mayer, George
2017-12-01
Ceramics and glasses, in their monolithic forms, typically exhibit low fracture toughness values, but rigid natural marine ceramic and glass composites have shown remarkable resistance to mechanical failure. This has been observed in load-extension behavior by recognizing that the total area under the curve, notably the part beyond the yield point, often conveys substantial capacity to carry mechanical load. The mechanisms underlying the latter observations are proposed as defining factors for toughness that provide resistance to failure, or capability to dissipate energy, rather than fracture toughness. Such behavior is exhibited in the spicules of glass sponges and in mollusk shells. There are a number of similarities in the manner in which energy dissipation takes place in both sponges and mollusks. It was observed that crack diversion, a new form of crack bridging, creation of new surface area, and other important energy-dissipating mechanisms occur and aid in "toughening". Crack tolerance, key to energy dissipation in these natural composite materials, is assisted by promoting energy distribution over large volumes of loaded specimens by minor components of organic constituents that also serve important roles as adhesives. Viscoelastic deformation was a notable characteristic of the organic component. Some of these energy-dissipating modes and characteristics were found to be quite different from the toughening mechanisms that are utilized for more conventional structural composites. Complementary to those mechanisms found in rigid natural ceramic/organic composites, layered architectures and very thin organic layers played major roles in energy dissipation in these structures. It has been demonstrated in rigid natural marine composites that not only architecture, but also the mechanical behavior of the individual constituents, the nature of the interfaces, and interfacial bonding play important roles in energy dissipation. Additionally, the controlling
Morphing of the Dissipative Reaction Mechanism
International Nuclear Information System (INIS)
Schroeder, W.U.; Toke, J.; Gawlikowicz, W.; Houck, M.A.; Lu, J.; Pienkowski, L.
2003-01-01
Important trends in the evolution of heavy-ion reaction mechanisms with bombarding energy and impact parameter are reviewed. Essential features of dissipative reactions appear preserved at E/A = 50-62 MeV, such as dissipative orbiting and multi-nucleon exchange. The relaxation of the A/Z asymmetry with impact parameter is slow. Non-equilibrium emission of light particles and clusters is an important process accompanying the evolution of the mechanism. Evidence is presented for a new mechanism of statistical cluster emission from hot, metastable primary reaction products, driven by surface entropy. These results suggest a plausible reinterpretation of multi-fragmentation. (authors)
Dissipation in the superfluid helium film
International Nuclear Information System (INIS)
Turkington, R.R.; Harris-Lowe, R.F.
1977-01-01
We have measured the rate of energy dissipation in superfluid helium film flow in an attempt to test a recent theory due to Harris-Lowe, which predicts that for superfluid stream velocities v/sub s/ that just exceed the critical velocity v/sub c0/, the rate of dissipation is given by an equation of the form Q=C(v/sub s/-v/sub c0/)/sup 3/2/. Our experiments at 1.33 K show that the exponent, predicted to be 3/2, is 1.491 +- 0.021
Dissipation and decoherence in quantum systems
International Nuclear Information System (INIS)
Menskii, Mikhail B
2003-01-01
The theory of dissipative quantum systems and its relation to the quantum theory of continuous measurements are reviewed. Constructing a correct theory of a dissipative quantum system requires that the system's interaction with its environment (reservoir) be taken into account. Since information about the system is 'recorded' in the state of the reservoir, the quantum theory of continuous measurements can be used to account for the influence of the reservoir. If based on the use of restricted path integrals, this theory does not require an explicit reservoir model and is therefore much simpler technically. (reviews of topical problems)
Morphing of the Dissipative Reaction Mechanism
Energy Technology Data Exchange (ETDEWEB)
Schroeder, W.U.; Toke, J.; Gawlikowicz, W.; Houck, M.A.; Lu, J.; Pienkowski, L. [Rochester Univ., Dept. of Chemistry, Rochester, NY (United States)
2003-07-01
Important trends in the evolution of heavy-ion reaction mechanisms with bombarding energy and impact parameter are reviewed. Essential features of dissipative reactions appear preserved at E/A = 50-62 MeV, such as dissipative orbiting and multi-nucleon exchange. The relaxation of the A/Z asymmetry with impact parameter is slow. Non-equilibrium emission of light particles and clusters is an important process accompanying the evolution of the mechanism. Evidence is presented for a new mechanism of statistical cluster emission from hot, metastable primary reaction products, driven by surface entropy. These results suggest a plausible reinterpretation of multi-fragmentation. (authors)
Periodic solutions of dissipative systems revisited
Directory of Open Access Journals (Sweden)
Górniewicz Lech
2006-01-01
Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.
Periodic solutions of dissipative systems revisited
Directory of Open Access Journals (Sweden)
Lech Górniewicz
2006-05-01
Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.
Appendix to Power Dissipation in Division
DEFF Research Database (Denmark)
Liu, Wei; Nannarelli, Alberto
This document is an appendix to the paper: Wei Liu and Alberto Nannarelli, ”Power Dissipation in Division”, Proc. of 42nd Asilomar Conference on Signals, Systems, and Computers, October 2008. The purpose of the document is to provide the necessary information for the implementation of the archite......This document is an appendix to the paper: Wei Liu and Alberto Nannarelli, ”Power Dissipation in Division”, Proc. of 42nd Asilomar Conference on Signals, Systems, and Computers, October 2008. The purpose of the document is to provide the necessary information for the implementation...
Dynamically controlled energy dissipation for fast magnetic vortex switching
Badea, R.; Berezovsky, J.
2017-09-01
Manipulation of vortex states in magnetic media provides new routes towards information storage and processing technology. The typical slow relaxation times (˜100 ns) of magnetic vortex dynamics may present an obstacle to the realization of these applications. Here, we investigate how a vortex state in a ferromagnetic microdisk can be manipulated in a way that translates the vortex core while enhancing energy dissipation to rapidly damp the vortex dynamics. We use time-resolved differential magneto-optical Kerr effect microscopy to measure the motion of the vortex core in response to applied magnetic fields. We first map out how the vortex core becomes sequentially trapped by pinning sites as it translates across the disk. After applying a fast magnetic field step to translate the vortex from one pinning site to another, we observe long-lived dynamics of the vortex as it settles to the new equilibrium. We then demonstrate how the addition of a short (<10 ns) magnetic field pulse can induce additional energy dissipation, strongly damping the long-lived dynamics. A model of the vortex dynamics using the Thiele equation of motion explains the mechanism behind this effect.
International Nuclear Information System (INIS)
Ma Bin; He Yan; Chen Huaihai; Xu Jianming; Rengel, Zed
2010-01-01
Polycyclic aromatic hydrocarbons (PAHs) are widespread and persistent organic pollutants with high carcinogenic effect and toxicity; their behavior and fate in the soil-plant system have been widely investigated. In the present paper, meta-analysis was used to explore the interaction between plant growth and dissipation of PAHs in soil based on the large body of published literature. Plants have a promoting effect on PAH dissipation in soils. There was no difference in PAH dissipation between soils contaminated with single and mixed PAHs. However, plants had a more obvious effect on PAH dissipation in freshly-spiked soils than in long-term field-polluted soils. Additionally, a positive effect of the number of microbial populations capable of degrading PAHs was observed in the rhizosphere compared with the bulk soil. Our meta-analysis established the importance of the rhizosphere effect on PAH dissipation in variety of the soil-plant systems. - The meta-analysis provides the first quantitative evidence of the positive effect of rhizosphere processes on PAH dissipation.
International Nuclear Information System (INIS)
Brard, D.
1982-11-01
In the aim of studying the climatic variations related to the reversal of the geomagnetic field, an analysis has been made of the effects of precipitations of galactic and solar protons, on oxide of nitrogen (NOsub(x) and NO) and ozone. Modifications are introduced into the one- and two-dimensional models which take into account the structure of the magnetic field. In situ measurements after the solar event of August 1972 enable changes due to the solar cycles to be introduced and the use of a 2D model to be justified [fr
Tidal heating in multilayered terrestrial exoplanets
Energy Technology Data Exchange (ETDEWEB)
Henning, Wade G.; Hurford, Terry, E-mail: wade.g.henning@nasa.gov [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)
2014-07-01
The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R{sub E} is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.
Tidal Heating in Multilayered Terrestrial Exoplanets
Henning, Wade G.; Hurford, Terry
2014-01-01
The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R(sub E) is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.
Tidal heating in multilayered terrestrial exoplanets
International Nuclear Information System (INIS)
Henning, Wade G.; Hurford, Terry
2014-01-01
The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R E is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.
Functional methods and mappings of dissipative quantum systems
International Nuclear Information System (INIS)
Baur, H.
2006-01-01
In the first part of this work we extract the algebraic structure behind the method of the influence functional in the context of dissipative quantum mechanics. Special emphasis was put on the transition from a quantum mechanical description to a classical one, since it allows a deeper understanding of the measurement-process. This is tightly connected with the transition from a microscopic to a macroscopic world where the former one is described by the rules of quantum mechanics whereas the latter follows the rules of classical mechanics. In addition we show how the results of the influence functional method can be interpreted as a stochastical process, which in turn allows an easy comparison with the well known time development of a quantum mechanical system by use of the Schroedinger equation. In the following we examine the tight-binding approximation of models of which their hamiltionian shows discrete eigenstates in position space and where transitions between those states are suppressed so that propagation either is described by tunneling or by thermal activation. In the framework of dissipative quantum mechanics this leads to a tremendous simplification of the effective description of the system since instead of looking at the full history of all paths in the path integral description, we only have to look at all possible jump times and the possible corresponding set of weights for the jump direction, which is much easier to handle both analytically and numerically. In addition we deal with the mapping and the connection of dissipative quantum mechanical models with ones in quantum field theory and in particular models in statistical field theory. As an example we mention conformal invariance in two dimensions which always becomes relevant if a statistical system only has local interaction and is invariant under scaling. (orig.)
Arctic Terrestrial Biodiversity Monitoring Plan
DEFF Research Database (Denmark)
Christensen, Tom; Payne, J.; Doyle, M.
The Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council, established the Circumpolar Biodiversity Monitoring Program (CBMP) to address the need for coordinated and standardized monitoring of Arctic environments. The CBMP includes an international...... on developing and implementing long-term plans for monitoring the integrity of Arctic biomes: terrestrial, marine, freshwater, and coastal (under development) environments. The CBMP Terrestrial Expert Monitoring Group (CBMP-TEMG) has developed the Arctic Terrestrial Biodiversity Monitoring Plan (CBMP......-Terrestrial Plan/the Plan) as the framework for coordinated, long-term Arctic terrestrial biodiversity monitoring. The goal of the CBMP-Terrestrial Plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect, understand and report on long...
Nonequilibrium chiral fluid dynamics including dissipation and noise
International Nuclear Information System (INIS)
Nahrgang, Marlene; Herold, Christoph; Bleicher, Marcus; Leupold, Stefan
2011-01-01
We present a consistent theoretical approach for the study of nonequilibrium effects in chiral fluid dynamics within the framework of the linear σ model with constituent quarks. Treating the quarks as an equilibrated heat bath, we use the influence functional formalism to obtain a Langevin equation for the σ field. This allows us to calculate the explicit form of the damping coefficient and the noise correlators. For a self-consistent derivation of both the dynamics of the σ field and the quark fluid, we have to employ the 2PI (two-particle irreducible) effective action formalism. The energy dissipation from the field to the fluid is treated in the exact formalism of the 2PI effective action where a conserved energy-momentum tensor can be constructed. We derive its form and comment on approximations generating additional terms in the energy-momentum balance of the entire system.
Neoclassical dissipation and resistive wall modes in tokamaks
International Nuclear Information System (INIS)
Shaing, K.C.
2004-01-01
It is shown that the critical toroidal plasma flow speed that is required to stabilize the resistive wall mode in tokamaks is reduced by a factor of the order of B/B θ or of 1.265ε 3sol4 B/B θ depending on the plasma parameters when the perturbed neoclassical viscosity driven current is taken into account. Here, B is the magnetic field strength, B θ is the poloidal magnetic field strength, and ε is the inverse aspect ratio. This effect is illustrated using an existing model for the resistive wall modes by including the neoclassical dissipation in the derivation of the dispersion relation. The derivation is based on fluid equations with the plasma viscosity, calculated using kinetic equation, as the closure. The reduction of the critical toroidal speed is a consequence of the parallel (to the magnetic field B) momentum equation when neoclassical viscosity becomes important. The results are compared with experimental observations in tokamaks
Friction and dissipative phenomena in quantum mechanics
International Nuclear Information System (INIS)
Kostin, M.D.
1975-01-01
Frictional and dissipative terms of the Schroedinger equation are studied. A proof is given showing that the frictional term of the Schroedinger--Langevin equation causes the quantum system to lose energy. General expressions are derived for the frictional term of the Schroedinger equation. (U.S.)
On multi-dissipative dynamic systems
DEFF Research Database (Denmark)
Thygesen, Uffe Høgsbro
1999-01-01
We consider deterministic dynamic systems with state space representations which are dissipative in the sense of Willems (1972) with respect to several supply rates. This property is of interest in robustness analysis and in multi-objective control. We give conditions under which the convex cone...
Quantum phase transition with dissipative frustration
Maile, D.; Andergassen, S.; Belzig, W.; Rastelli, G.
2018-04-01
We study the quantum phase transition of the one-dimensional phase model in the presence of dissipative frustration, provided by an interaction of the system with the environment through two noncommuting operators. Such a model can be realized in Josephson junction chains with shunt resistances and resistances between the chain and the ground. Using a self-consistent harmonic approximation, we determine the phase diagram at zero temperature which exhibits a quantum phase transition between an ordered phase, corresponding to the superconducting state, and a disordered phase, corresponding to the insulating state with localized superconducting charge. Interestingly, we find that the critical line separating the two phases has a nonmonotonic behavior as a function of the dissipative coupling strength. This result is a consequence of the frustration between (i) one dissipative coupling that quenches the quantum phase fluctuations favoring the ordered phase and (ii) one that quenches the quantum momentum (charge) fluctuations leading to a vanishing phase coherence. Moreover, within the self-consistent harmonic approximation, we analyze the dissipation induced crossover between a first and second order phase transition, showing that quantum frustration increases the range in which the phase transition is second order. The nonmonotonic behavior is reflected also in the purity of the system that quantifies the degree of correlation between the system and the environment, and in the logarithmic negativity as an entanglement measure that encodes the internal quantum correlations in the chain.
Dissipative preparation of entanglement in optical cavities
DEFF Research Database (Denmark)
Kastoryano, Michael James; Reiter, Florentin; Sørensen, Anders Søndberg
2011-01-01
We propose a novel scheme for the preparation of a maximally entangled state of two atoms in an optical cavity. Starting from an arbitrary initial state, a singlet state is prepared as the unique fixed point of a dissipative quantum dynamical process. In our scheme, cavity decay is no longer...
Characterizing pesticide dissipation in food crops
DEFF Research Database (Denmark)
Fantke, Peter; Juraske, R.; Jolliet, O.
2013-01-01
Ingestion of residues via consumption of food crops is the predominant exposure route of the general population toward pesticides. However, pesticide dissipation in crops constitutes a main source of uncertainty in estimating residues in harvested crop parts and subsequent human exposure. Neverth......Ingestion of residues via consumption of food crops is the predominant exposure route of the general population toward pesticides. However, pesticide dissipation in crops constitutes a main source of uncertainty in estimating residues in harvested crop parts and subsequent human exposure....... Nevertheless, dissipation is a key mechanism in models assessing pesticide distribution in the cropenvironment and the magnitude of residues in harvest. We provide a consistent framework for characterizing pesticide dissipation in food crops for use in modeling approaches applied in health risk and impact...... degradation is dominating. We are currently testing the regression to predict degradation half-lives in crops. By providing mean degradation half-lives at 20°C for more than 300 pesticides, we reduce uncertainty and improve assumptions in current practice of health risk and impact assessments....
Viscosity measurement techniques in Dissipative Particle Dynamics
Boromand, Arman; Jamali, Safa; Maia, Joao M.
2015-11-01
In this study two main groups of viscosity measurement techniques are used to measure the viscosity of a simple fluid using Dissipative Particle Dynamics, DPD. In the first method, a microscopic definition of the pressure tensor is used in equilibrium and out of equilibrium to measure the zero-shear viscosity and shear viscosity, respectively. In the second method, a periodic Poiseuille flow and start-up transient shear flow is used and the shear viscosity is obtained from the velocity profiles by a numerical fitting procedure. Using the standard Lees-Edward boundary condition for DPD will result in incorrect velocity profiles at high values of the dissipative parameter. Although this issue was partially addressed in Chatterjee (2007), in this work we present further modifications (Lagrangian approach) to the original LE boundary condition (Eulerian approach) that will fix the deviation from the desired shear rate at high values of the dissipative parameter and decrease the noise to signal ratios in stress measurement while increases the accessible low shear rate window. Also, the thermostat effect of the dissipative and random forces is coupled to the dynamic response of the system and affects the transport properties like the viscosity and diffusion coefficient. We investigated thoroughly the dependency of viscosity measured by both Eulerian and Lagrangian methodologies, as well as numerical fitting procedures and found that all the methods are in quantitative agreement.
Energy and dissipated work in snow avalanches
Bartelt, P.; Buser, O.
2004-12-01
Using the results of large scale avalanche experiments at the Swiss Vallée de la Sionne test site, the energy balance of several snow avalanches is determined. Avalanches convert approximately one-seventh of their potential energy into kinetic energy. The total potential energy depends strongly on the entrained snowcover, indicating that entrainment processes cannot be ignored when predicting terminal velocities and runout distances. We find energy dissipation rates on the order of 1 GW. Fluidization of the fracture slab can be identified in the experiments as an increase in dissipation rate, thereby explaining the initial and rapid acceleration of avalanches after release. Interestingly, the dissipation rates appear to be constant along the track, although large fluctuations in internal velocity exist. Thus, we can demonstrate within the context of non-equilibrium thermodynamics that -- in space -- granular snow avalanches are irreversible, dissipative systems that minimize entropy production because they appear to reach a steady-state non-equilibrium. A thermodynamic analysis reveals that fluctuations in velocity depend on the roughness of the flow surface and viscosity of the granular system. We speculate that this property explains the transition from flowing avalanches to powder avalanches.
Contaminant exposure in terrestrial vertebrates
International Nuclear Information System (INIS)
Smith, Philip N.; Cobb, George P.; Godard-Codding, Celine; Hoff, Dale; McMurry, Scott T.; Rainwater, Thomas R.; Reynolds, Kevin D.
2007-01-01
Here we review mechanisms and factors influencing contaminant exposure among terrestrial vertebrate wildlife. There exists a complex mixture of biotic and abiotic factors that dictate potential for contaminant exposure among terrestrial and semi-terrestrial vertebrates. Chemical fate and transport in the environment determine contaminant bioaccessibility. Species-specific natural history characteristics and behavioral traits then play significant roles in the likelihood that exposure pathways, from source to receptor, are complete. Detailed knowledge of natural history traits of receptors considered in conjunction with the knowledge of contaminant behavior and distribution on a site are critical when assessing and quantifying exposure. We review limitations in our understanding of elements of exposure and the unique aspects of exposure associated with terrestrial and semi-terrestrial taxa. We provide insight on taxa-specific traits that contribute, or limit exposure to, transport phenomenon that influence exposure throughout terrestrial systems, novel contaminants, bioavailability, exposure data analysis, and uncertainty associated with exposure in wildlife risk assessments. Lastly, we identify areas related to exposure among terrestrial and semi-terrestrial organisms that warrant additional research. - Both biotic and abiotic factors determine chemical exposure for terrestrial vertebrates
Energy Dissipation in the Upper Atmospheres of TRAPPIST-1 Planets
Cohen, Ofer; Glocer, Alex; Garraffo, Cecilia; Drake, Jeremy J.; Bell, Jared M.
2018-03-01
We present a method to quantify the upper limit of the energy transmitted from the intense stellar wind to the upper atmospheres of three of the TRAPPIST-1 planets (e, f, and g). We use a formalism that treats the system as two electromagnetic regions, where the efficiency of the energy transmission between one region (the stellar wind at the planetary orbits) to the other (the planetary ionospheres) depends on the relation between the conductances and impedances of the two regions. Since the energy flux of the stellar wind is very high at these planetary orbits, we find that for the case of high transmission efficiency (when the conductances and impedances are close in magnitude), the energy dissipation in the upper planetary atmospheres is also very large. On average, the Ohmic energy can reach 0.5–1 W m‑2, about 1% of the stellar irradiance and 5–15 times the EUV irradiance. Here, using constant values for the ionospheric conductance, we demonstrate that the stellar wind energy could potentially drive large atmospheric heating in terrestrial planets, as well as in hot Jupiters. More detailed calculations are needed to assess the ionospheric conductance and to determine more accurately the amount of heating the stellar wind can drive in close-orbit planets.
Coherent control of the single-photon multichannel scattering in the dissipation case
Shi, Yun-Xia; Wang, Hang-Yu; Ma, Jin-Lou; Li, Qing; Tan, Lei
2018-03-01
Based on the quasi-boson approach, a model of a Λ-type three-level atom coupled to a X-shaped coupled cavity arrays (CCAs) is used to study the transport properties of a single-photon in the dissipative case, and a classical field is introduced to motivate the one transition of the Λ-type three-level atom (ΛTLA). The analytical expressions of transmission and transfer rate are obtained. Our results show that the cavity dissipation will obviously weaken the single-photon transfer rate where the incident energy of the single photon is resonant with the excited energy of the atom. Whether the cavity dissipation exists or not, the single photon can be almost confined in the incident channel at large detuning, and we can regulate the intensity of the classical field to control the total transmission of the single-photon.
Energy density of a dissipative polarizable solid by a Lagrangean formalism
International Nuclear Information System (INIS)
Englman, R.; Yahalom, A.
2003-01-01
A Lagrangean for the dynamics of an electromagnetic field in a dispersive and dissipative material is constructed (adapting some ideas by Bekenstein and Hannay) and an expression for the energy density that is positive is obtained from it. The expression contains extra (sink) degrees of freedom that represent dissipating modes. In simplified cases the sink modes can be eliminated to yield an energy density expression in terms of the electromagnetic fields, the polarization and the magnetization only, but which contains parameters associated with the sink modes. The method of adding extra modes can be used to set up a Lagrangean formalism for dissipative systems in general, such that will reinstate time-translation invariance and will yield a unique energy density
TERRESTRIAL PLANET FORMATION FROM AN ANNULUS
Energy Technology Data Exchange (ETDEWEB)
Walsh, Kevin J.; Levison, Harold F., E-mail: kwalsh@boulder.swri.edu [Southwest Research Institute, 1050 Walnut St. Suite 300, Boulder, CO 80302 (United States)
2016-09-01
It has been shown that some aspects of the terrestrial planets can be explained, particularly the Earth/Mars mass ratio, when they form from a truncated disk with an outer edge near 1.0 au. This has been previously modeled starting from an intermediate stage of growth utilizing pre-formed planetary embryos. We present simulations that were designed to test this idea by following the growth process from km-sized objects located between 0.7 and 1.0 au up to terrestrial planets. The simulations explore initial conditions where the solids in the disk are planetesimals with radii initially between 3 and 300 km, alternately including effects from a dissipating gaseous solar nebula and collisional fragmentation. We use a new Lagrangian code known as LIPAD, which is a particle-based code that models the fragmentation, accretion, and dynamical evolution of a large number of planetesimals, and can model the entire growth process from km-sizes up to planets. A suite of large (∼ Mars mass) planetary embryos is complete in only ∼1 Myr, containing most of the system mass. A quiescent period then persists for 10–20 Myr characterized by slow diffusion of the orbits and continued accretion of the remaining planetesimals. This is interrupted by an instability that leads to embryos crossing orbits and embryo–embryo impacts that eventually produce the final set of planets. While this evolution is different than that found in other works exploring an annulus, the final planetary systems are similar, with roughly the correct number of planets and good Mars-analogs.
Rodell, M.; Chambers, D. P.; Famiglietti, J. S.
2015-01-01
During 2014 dryness continued in the Northern Hemisphere and relative wetness continued in the Southern Hemisphere (Fig. 2.21; Plate 2.1g). These largely canceled out such that the global land surface began and ended the year with a terrestrial water storage (TWS) anomaly slightly below 0 cm (equivalent height of water; Fig. 2.22). TWS is the sum of groundwater, soil moisture, surface water, snow, and ice. Groundwater responds more slowly to meteorological phenomena than the other components because the overlying soil acts as a low pass filter, but often it has a larger range of variability on multiannual timescales (Rodell and Famiglietti 2001; Alley et al. 2002).In situ groundwater data are only archived and made and Tanzania. The rest of the continent experienced mixed to dry conditions. Significant reductions in TWS in Greenland, Antarctica, and southern coastal Alaska reflect ongoing ice sheet and glacier ablation, not groundwater depletion.
Quantum dissipative dynamics and decoherence of dimers on helium droplets
International Nuclear Information System (INIS)
Schlesinger, Martin
2011-01-01
In this thesis, quantum dynamical simulations are performed in order to describe the vibrational motion of diatomic molecules in a highly quantum environment, so-called helium droplets. We aim to reproduce and explain experimental findings which were obtained from dimers on helium droplets. Nanometer-sized helium droplets contain several thousands of 4 He atoms. They serve as a host for embedded atoms or molecules and provide an ultracold ''refrigerator'' for them. Spectroscopy of molecules in or on these droplets reveals information on both the molecule and the helium environment. The droplets are known to be in the superfluid He II phase. Superfluidity in nanoscale systems is a steadily growing field of research. Spectra obtained from full quantum simulations for the unperturbed dimer show deviations from measurements with dimers on helium droplets. These deviations result from the influence of the helium environment on the dimer dynamics. In this work, a well-established quantum optical master equation is used in order to describe the dimer dynamics effectively. The master equation allows to describe damping fully quantum mechanically. By employing that equation in the quantum dynamical simulation, one can study the role of dissipation and decoherence in dimers on helium droplets. The effective description allows to explain experiments with Rb 2 dimers on helium droplets. Here, we identify vibrational damping and associated decoherence as the main explanation for the experimental results. The relation between decoherence and dissipation in Morse-like systems at zero temperature is studied in more detail. The dissipative model is also used to investigate experiments with K 2 dimers on helium droplets. However, by comparing numerical simulations with experimental data, one finds that further mechanisms are active. Here, a good agreement is obtained through accounting for rapid desorption of dimers. We find that decoherence occurs in the electronic manifold of the
Grand scheme for solar-terrestrial research
International Nuclear Information System (INIS)
Intriligator, D.S.
1985-01-01
The study of solar wind and its interaction with magnetic fields and electrical currents is examined. The effects of magnetic storms caused by solar wind interaction with magnetic fields in the magnetosphere and ionosphere are described. The effect of magnetospheric plasma processes on spacecraft operations and the operation of ground-based systems are explained. The development of an International Solar Terrestrial Physics program, which will be designed to place diagnostic experiments on a collection of spacecraft positioned near space is discussed; the components of the program are described
Handbook of the Solar-Terrestrial Environment
Kamide, Y
2007-01-01
The Handbook of the Solar-Terrestrial Environment is a unique compendium. Recognized international leaders in their field contribute chapters on basic topics of solar physics, space plasmas and the Earth's magnetosphere, and on applied topics like the aurora, magnetospheric storms, space weather, space climatology and planetary science. This book will be of highest value as a reference for researchers working in the area of planetary and space science. However, it is also written in a style accessible to graduate students majoring in those fields.
Sampling Terrestrial Environments for Bacterial Polyketides
Directory of Open Access Journals (Sweden)
Patrick Hill
2017-04-01
Full Text Available Bacterial polyketides are highly biologically active molecules that are frequently used as drugs, particularly as antibiotics and anticancer agents, thus the discovery of new polyketides is of major interest. Since the 1980s discovery of polyketides has slowed dramatically due in large part to the repeated rediscovery of known compounds. While recent scientific and technical advances have improved our ability to discover new polyketides, one key area has been under addressed, namely the distribution of polyketide-producing bacteria in the environment. Identifying environments where producing bacteria are abundant and diverse should improve our ability to discover (bioprospect new polyketides. This review summarizes for the bioprospector the state-of-the-field in terrestrial microbial ecology. It provides insight into the scientific and technical challenges limiting the application of microbial ecology discoveries for bioprospecting and summarizes key developments in the field that will enable more effective bioprospecting. The major recent efforts by researchers to sample new environments for polyketide discovery is also reviewed and key emerging environments such as insect associated bacteria, desert soils, disease suppressive soils, and caves are highlighted. Finally strategies for taking and characterizing terrestrial samples to help maximize discovery efforts are proposed and the inclusion of non-actinomycetal bacteria in any terrestrial discovery strategy is recommended.
Storage functions for dissipative linear systems are quadratic state functions
Trentelman, Harry L.; Willems, Jan C.
1997-01-01
This paper deals with dissipative dynamical systems. Dissipative dynamical systems can be used as models for physical phenomena in which energy exchange with their environment plays a role. In a dissipative dynamical system, the book-keeping of energy is done via the supply rate and a storage
Spiral arms, comets and terrestrial catastrophism
International Nuclear Information System (INIS)
Clube, S.V.M.; Napier, W.M.
1982-01-01
A review is presented of an hypothesis of terrestrial catastrophism in which comets grow in molecular clouds and are captured by the Sun as it passes through the spiral arms of the Galaxy. Assuming that comets are a major supplier of the Earth-crossing (Appollo) asteroid population, the latter fluctuates correspondingly and leads to episodes of terrestrial bombardment. Changes in the rotational momentum of core and mantle, generated by impacts, lead to episodes of magnetic field reversal and tectonic activity, while surface phenomena lead to ice-ages and mass extinctions. An episodic geophysical history with an interstellar connection is thus implied. If comets in spiral arms are necessary intermediaries in the process of star formation, the theory also has implications relating to early solar system history and galactic chemistry. These aspects are briefly discussed with special reference to the nature of spiral arms. (author)
Dissipation and the relaxation to equilibrium
International Nuclear Information System (INIS)
Evans, Denis J; Williams, Stephen R; Searles, Debra J
2009-01-01
Using the recently derived dissipation theorem and a corollary of the transient fluctuation theorem (TFT), namely the second-law inequality, we derive the unique time independent, equilibrium phase space distribution function for an ergodic Hamiltonian system in contact with a remote heat bath. We prove under very general conditions that any deviation from this equilibrium distribution breaks the time independence of the distribution. Provided temporal correlations decay, we show that any nonequilibrium distribution that is an even function of the momenta eventually relaxes (not necessarily monotonically) to the equilibrium distribution. Finally we prove that the negative logarithm of the microscopic partition function is equal to the thermodynamic Helmholtz free energy divided by the thermodynamic temperature and Boltzmann's constant. Our results complement and extend the findings of modern ergodic theory and show the importance of dissipation in the process of relaxation towards equilibrium
Non-dissipative effects in nonequilibrium systems
Maes, Christian
2018-01-01
This book introduces and discusses both the fundamental aspects and the measurability of applications of time-symmetric kinetic quantities, outlining the features that constitute the non-dissipative branch of non-equilibrium physics. These specific features of non-equilibrium dynamics have largely been ignored in standard statistical mechanics texts. This introductory-level book offers novel material that does not take the traditional line of extending standard thermodynamics to the irreversible domain. It shows that although stationary dissipation is essentially equivalent with steady non-equilibrium and ubiquitous in complex phenomena, non-equilibrium is not determined solely by the time-antisymmetric sector of energy-entropy considerations. While this should not be very surprising, this book provides timely, simple reminders of the role of time-symmetric and kinetic aspects in the construction of non-equilibrium statistical mechanics.
On the Lagrangian description of dissipative systems
Martínez-Pérez, N. E.; Ramírez, C.
2018-03-01
We consider the Lagrangian formulation with duplicated variables of dissipative mechanical systems. The application of Noether theorem leads to physical observable quantities which are not conserved, like energy and angular momentum, and conserved quantities, like the Hamiltonian, that generate symmetry transformations and do not correspond to observables. We show that there are simple relations among the equations satisfied by these two types of quantities. In the case of the damped harmonic oscillator, from the quantities obtained by the Noether theorem follows the algebra of Feshbach and Tikochinsky. Furthermore, if we consider the whole dynamics, the degrees of freedom separate into a physical and an unphysical sector. We analyze several cases, with linear and nonlinear dissipative forces; the physical consistency of the solutions is ensured, observing that the unphysical sector has always the trivial solution.
Dissipative Boltzmann-Robertson-Walker cosmologies
International Nuclear Information System (INIS)
Hiscock, W.A.; Salmonson, J.
1991-01-01
The equations governing a flat Robertson-Walker cosmological model containing a dissipative Boltzmann gas are integrated numerically. The bulk viscous stress is modeled using the Eckart and Israel-Stewart theories of dissipative relativistic fluids; the resulting cosmologies are compared and contrasted. The Eckart models are shown to always differ in a significant quantitative way from the Israel-Stewart models. It thus appears inappropriate to use the pathological (nonhyperbolic) Eckart theory for cosmological applications. For large bulk viscosities, both cosmological models approach asymptotic nonequilibrium states; in the Eckart model the total pressure is negative, while in the Israel-Stewart model the total pressure is asymptotically zero. The Eckart model also expands more rapidly than the Israel-Stewart models. These results suggest that ''bulk-viscous'' inflation may be an artifact of using a pathological fluid theory such as the Eckart theory
Astrophysical constraints on Planck scale dissipative phenomena.
Liberati, Stefano; Maccione, Luca
2014-04-18
The emergence of a classical spacetime from any quantum gravity model is still a subtle and only partially understood issue. If indeed spacetime is arising as some sort of large scale condensate of more fundamental objects, then it is natural to expect that matter, being a collective excitation of the spacetime constituents, will present modified kinematics at sufficiently high energies. We consider here the phenomenology of the dissipative effects necessarily arising in such a picture. Adopting dissipative hydrodynamics as a general framework for the description of the energy exchange between collective excitations and the spacetime fundamental degrees of freedom, we discuss how rates of energy loss for elementary particles can be derived from dispersion relations and used to provide strong constraints on the base of current astrophysical observations of high-energy particles.
Investigation of energy dissipation in meat with an experimental ultrasonic device
International Nuclear Information System (INIS)
Stasiak, D.M.; Dolatowski, Z.
2000-01-01
The phenomena concomitant with acoustic energy dissipation in meat were studied. An experimental ultrasonic device (25-37 kHz, 2 W/square cm) was applied. Measurements of meat temperature in ultrasonic field showed the temperature rise significant for technological reasons. In this respect the changes in water absorption ability and acidity of meat were also examined
Dissipation in graphene and nanotube resonators
Seoánez, C.; Guinea, F.; Castro Neto, A. H.
2007-09-01
Different damping mechanisms in graphene nanoresonators are studied: charges in the substrate, ohmic losses in the substrate and the graphene sheet, breaking and healing of surface bonds (Velcro effect), two level systems, attachment losses, and thermoelastic losses. We find that, for realistic structures and contrary to semiconductor resonators, dissipation is dominated by ohmic losses in the graphene layer and metallic gate. An extension of this study to carbon nanotube-based resonators is presented.
Dissipation in graphene and nanotube resonators
Seoanez, C.; Guinea, F.; Neto, A. H. Castro
2007-01-01
Different damping mechanisms in graphene nanoresonators are studied: charges in the substrate, ohmic losses in the substrate and the graphene sheet, breaking and healing of surface bonds (Velcro effect), two level systems, attachment losses, and thermoelastic losses. We find that, for realistic structures and contrary to semiconductor resonators, dissipation is dominated by ohmic losses in the graphene layer and metallic gate. An extension of this study to carbon nanotube-based resonators is ...
On local Hamiltonians and dissipative systems
Energy Technology Data Exchange (ETDEWEB)
Castagnino, M. [CONICET-Institutos de Fisica Rosario y de Astronomia y Fisica del Espacio Casilla de Correos 67, Sucursal 28, 1428, Buenos Aires (Argentina); Gadella, M. [Facultad de Ciencias Exactas, Ingenieria y Agrimensura UNR, Rosario (Argentina) and Departamento de Fisica Teorica, Facultad de Ciencias c. Real de Burgos, s.n., 47011 Valladolid (Spain)]. E-mail: manuelgadella@yahoo.com.ar; Lara, L.P. [Facultad de Ciencias Exactas, Ingenieria y Agrimensura UNR, Rosario (Argentina)
2006-11-15
We study a type of one-dimensional dynamical systems on the corresponding two-dimensional phase space. By using arguments related to the existence of integrating factors for Pfaff equations, we show that some one-dimensional non-Hamiltonian systems like dissipative systems, admit a Hamiltonian description by sectors on the phase plane. This picture is not uniquely defined and is coordinate dependent. A simple example is exhaustively discussed. The method, is not always applicable to systems with higher dimensions.
Dissipation and decoherence in Brownian motion
Energy Technology Data Exchange (ETDEWEB)
Bellomo, Bruno [Dipartimento di Scienze Fisiche ed Astronomiche dell' Universita di Palermo, Via Archirafi, 36, 90123 Palermo (Italy); Barnett, Stephen M [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Jeffers, John [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)
2007-05-15
We consider the evolution of a Brownian particle described by a measurement-based master equation. We derive the solution to this equation for general initial conditions and apply it to a Gaussian initial state. We analyse the effects of the diffusive terms, present in the master equation, and describe how these modify uncertainties and coherence length. This allows us to model dissipation and decoherence in quantum Brownian motion.
Offshore heat dissipation for nuclear energy centers
International Nuclear Information System (INIS)
Bauman, H.F.
1978-09-01
The technical, environmental, and economic aspects of utilizing the ocean or other large water bodies for the dissipation of reject heat from Nuclear Energy Centers (NECs) were investigated. An NEC in concept is an aggregate of nuclear power plants of 10 GW(e) capacity or greater on a common site. The use of once-through cooling for large power installations offers advantages including higher thermal efficiencies, especially under summer peak-load conditions, compared to closed-cycle cooling systems. A disadvantage of once-through cooling is the potential for greater adverse impacts on the aquatic environment. A concept is presented for minimizing the impacts of such systems by placing water intake and discharge locations relatively distant from shore in deeper water than has heretofore been the practice. This technique would avoid impacts on relatively biologically productive and ecologically sensitive shallow inshore areas. The NEC itself would be set back from the shoreline so that recreational use of the shore area would not be impaired. The characteristics of a heat-dissipation system of the size required for a NEC were predicted from the known characteristics of a smaller system by applying hydraulic scaling laws. The results showed that adequate heat dissipation can be obtained from NEC-sized systems located in water of appropriate depth. Offshore intake and discharge structures would be connected to the NEC pump house on shore via tunnels or buried pipelines. Tunnels have the advantage that shoreline and beach areas would not be disturbed. The cost of an offshore heat-dissipation system depends on the characteristics of the site, particularly the distance to suitably deep water and the type of soil or rock in which water conduits would be constructed. For a favorable site, the cost of an offshore system is estimated to be less than the cost of a closed-cycle system
Tidally Heated Terrestrial Exoplanets
Henning, Wade Garrett
This work models the surface and internal temperatures for hypothetical terrestrial planets in situations involving extreme tidal heating. The feasibility of such planets is evaluated in terms of the orbital perturbations that may give rise to them, their required proximity to a hoststar, and the potential for the input tidal heating to cause significant partial melting of the mantle. Trapping terrestrial planets into 2:1 resonances with migrating Hot Jupiters is considered as a reasonable way for Earth-like worlds to both maintain high eccentricities and to move to short enough orbital periods (1-20 days) for extreme tidal heating to occur. Secular resonance and secular orbital perturbations may support moderate tidal heating at a low equilibrium eccentricity. At orbital periods below 10-30 days, with eccentricities from 0.01 to 0.1, tidal heat may greatly exceed radiogenic heat production. It is unlikely to exceed insolation, except when orbiting very low luminosity hosts, and thus will have limited surface temperature expression. Observations of such bodies many not be able to detect tidal surface enhancements given a few percent uncertainty in albedo, except on the nightside of spin synchronous airless objects. Otherwise detection may occur via spectral detection of hotspots or high volcanic gas concentrations including sulfur dioxide and hydrogen sulfide. The most extreme cases may be able to produce magma oceans, or magma slush mantles with up to 40-60% melt fractions. Tides may alter the habitable zones for smaller red dwarf stars, but are generally detrimental. Multiple viscoelastic models, including the Maxwell, Voigt-Kelvin, Standard Anelastic Solid, and Burgers rheologies are explored and applied to objects such as Io and the super-Earth planet GJ 876d. The complex valued Love number for the Burgers rheology is derived and found to be a useful improvement when modeling the low temperature behavior of tidal bodies, particularly during low eccentricity
Crises in a dissipative bouncing ball model
Energy Technology Data Exchange (ETDEWEB)
Livorati, André L.P., E-mail: livorati@usp.br [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Caldas, Iberê L. [Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Dettmann, Carl P. [School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Leonel, Edson D. [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil)
2015-11-06
Highlights: • We studied a dissipative bouncing ball dynamics. • A two-dimensional nonlinear mapping describes the dynamics. • Crises between attractors and its manifolds were characterized. • A new physical crisis between vibrating platform and an attractor was characterized. • The existence of a ‘robust’ chaotic attractor was set. - Abstract: The dynamics of a bouncing ball model under the influence of dissipation is investigated by using a two-dimensional nonlinear mapping. When high dissipation is considered, the dynamics evolves to different attractors. The evolution of the basins of the attracting fixed points is characterized, as we vary the control parameters. Crises between the attractors and their boundaries are observed. We found that the multiple attractors are intertwined, and when the boundary crisis between their stable and unstable manifolds occurs, it creates a successive mechanism of destruction for all attractors originated by the sinks. Also, a physical impact crisis is described, an important mechanism in the reduction of the number of attractors.
Critical behavior in earthquake energy dissipation
Wanliss, James; Muñoz, Víctor; Pastén, Denisse; Toledo, Benjamín; Valdivia, Juan Alejandro
2017-09-01
We explore bursty multiscale energy dissipation from earthquakes flanked by latitudes 29° S and 35.5° S, and longitudes 69.501° W and 73.944° W (in the Chilean central zone). Our work compares the predictions of a theory of nonequilibrium phase transitions with nonstandard statistical signatures of earthquake complex scaling behaviors. For temporal scales less than 84 hours, time development of earthquake radiated energy activity follows an algebraic arrangement consistent with estimates from the theory of nonequilibrium phase transitions. There are no characteristic scales for probability distributions of sizes and lifetimes of the activity bursts in the scaling region. The power-law exponents describing the probability distributions suggest that the main energy dissipation takes place due to largest bursts of activity, such as major earthquakes, as opposed to smaller activations which contribute less significantly though they have greater relative occurrence. The results obtained provide statistical evidence that earthquake energy dissipation mechanisms are essentially "scale-free", displaying statistical and dynamical self-similarity. Our results provide some evidence that earthquake radiated energy and directed percolation belong to a similar universality class.
Relativistic electrodynamics of dissipative elastic media
International Nuclear Information System (INIS)
Kranys, M.
1980-01-01
A phenomenological general relativistic electrodynamics is proposed for a dissipative elastic solid which is polarizable and magnetizable and whose governing equations form a hyperbolic system. Non-stationary transport equations are proposed for dissipative fluxes (and constitutive equations of electrodynamics) containing new cross-effect terms, as required for compatibility with an entropy principle expressed by a new balance equation (including a new Gibbs equation). The dynamic equations are deduced from the unified Minkowski-Abraham-Eckart energy-momentum tensor. The theory, formed by a set of 29 (reducible to 23) partial differential equations (in special relativity) governing the material behaviour of the system characterized by generalizing the constitutive equations of quasineutral media, together with Maxwell's equations, may be referred to as the electrodynamics of dissipative elastic media (or fluid). The proposed transport laws for polarization and magnetization generalize the well-known Debye law for relaxation and show the influence of shear and bulk viscosity on polarization and magentization. Besides the form of the entropy function, the free energy function in the non-stationary regime is also formulated. (auth)
Correlated Photon Dynamics in Dissipative Rydberg Media
Zeuthen, Emil; Gullans, Michael J.; Maghrebi, Mohammad F.; Gorshkov, Alexey V.
2017-07-01
Rydberg blockade physics in optically dense atomic media under the conditions of electromagnetically induced transparency (EIT) leads to strong dissipative interactions between single photons. We introduce a new approach to analyzing this challenging many-body problem in the limit of a large optical depth per blockade radius. In our approach, we separate the single-polariton EIT physics from Rydberg-Rydberg interactions in a serialized manner while using a hard-sphere model for the latter, thus capturing the dualistic particle-wave nature of light as it manifests itself in dissipative Rydberg-EIT media. Using this approach, we analyze the saturation behavior of the transmission through one-dimensional Rydberg-EIT media in the regime of nonperturbative dissipative interactions relevant to current experiments. Our model is able to capture the many-body dynamics of bright, coherent pulses through these strongly interacting media. We compare our model with available experimental data in this regime and find good agreement. We also analyze a scheme for generating regular trains of single photons from continuous-wave input and derive its scaling behavior in the presence of imperfect single-photon EIT.
Moroz, Adam
2011-01-01
This book is the first unified systemic description of dissipative phenomena, taking place in biology, and non-dissipative (conservative) phenomena, which is more relevant to physics. Fully updated and revised, this new edition extends our understanding of nonlinear phenomena in biology and physics from the extreme / optimal perspective. The first book to provide understanding of physical phenomena from a biological perspective and biological phenomena from a physical perspective Discusses emerging fields and analysis Provides examples.
Nonlinear dissipative devices in structural vibration control: A review
Lu, Zheng; Wang, Zixin; Zhou, Ying; Lu, Xilin
2018-06-01
Structural vibration is a common phenomenon existing in various engineering fields such as machinery, aerospace, and civil engineering. It should be noted that the effective suppression of structural vibration is conducive to enhancing machine performance, prolonging the service life of devices, and promoting the safety and comfort of structures. Conventional linear energy dissipative devices (linear dampers) are largely restricted for wider application owing to their low performance under certain conditions, such as the detuning effect of tuned mass dampers subjected to nonstationary excitations and the excessively large forces generated in linear viscous dampers at high velocities. Recently, nonlinear energy dissipative devices (nonlinear dampers) with broadband response and high robustness are being increasingly used in practical engineering. At the present stage, nonlinear dampers can be classified into three groups, namely nonlinear stiffness dampers, nonlinear-stiffness nonlinear-damping dampers, and nonlinear damping dampers. Corresponding to each nonlinear group, three types of nonlinear dampers that are widely utilized in practical engineering are reviewed in this paper: the nonlinear energy sink (NES), particle impact damper (PID), and nonlinear viscous damper (NVD), respectively. The basic concepts, research status, engineering applications, and design approaches of these three types of nonlinear dampers are summarized. A comparison between their advantages and disadvantages in practical engineering applications is also conducted, to provide a reference source for practical applications and new research.
Alfvén wave dissipation in the solar chromosphere
Grant, Samuel D. T.; Jess, David B.; Zaqarashvili, Teimuraz V.; Beck, Christian; Socas-Navarro, Hector; Aschwanden, Markus J.; Keys, Peter H.; Christian, Damian J.; Houston, Scott J.; Hewitt, Rebecca L.
2018-05-01
Magnetohydrodynamic Alfvén waves1 have been a focus of laboratory plasma physics2 and astrophysics3 for over half a century. Their unique nature makes them ideal energy transporters, and while the solar atmosphere provides preferential conditions for their existence4, direct detection has proved difficult as a result of their evolving and dynamic observational signatures. The viability of Alfvén waves as a heating mechanism relies upon the efficient dissipation and thermalization of the wave energy, with direct evidence remaining elusive until now. Here we provide the first observational evidence of Alfvén waves heating chromospheric plasma in a sunspot umbra through the formation of shock fronts. The magnetic field configuration of the shock environment, alongside the tangential velocity signatures, distinguish them from conventional umbral flashes5. Observed local temperature enhancements of 5% are consistent with the dissipation of mode-converted Alfvén waves driven by upwardly propagating magneto-acoustic oscillations, providing an unprecedented insight into the behaviour of Alfvén waves in the solar atmosphere and beyond.
Ductile crack growth simulation from near crack tip dissipated energy
International Nuclear Information System (INIS)
Marie, S.; Chapuliot, S.
2000-01-01
A method to calculate ductile tearing in both small scale fracture mechanics specimens and cracked components is presented. This method is based on an estimation of the dissipated energy calculated near the crack tip. Firstly, the method is presented. It is shown that a characteristic parameter G fr can be obtained, relevant to the dissipated energy in the fracture process. The application of the method to the calculation of side grooved crack tip (CT) specimens of different sizes is examined. The value of G fr is identified by comparing the calculated and experimental load line displacement versus crack extension curve for the smallest CT specimen. With this identified value, it is possible to calculate the global behaviour of the largest specimen. The method is then applied to the calculation of a pipe containing a through-wall thickness crack subjected to a bending moment. This pipe is made of the same material as the CT specimens. It is shown that it is possible to simulate the global behaviour of the structure including the prediction of up to 90-mm crack extension. Local terms such as the equivalent stress or the crack tip opening angle are found to be constant during the crack extension process. This supports the view that G fr controls the fields in the vicinity near the crack tip. (orig.)
Ecological transfer mechanisms - Terrestrial
International Nuclear Information System (INIS)
Martin, W.E.; Raines, Gilbert E.; Bloom, S.G.; Levin, A.A.
1969-01-01
Radionuclides produced by nuclear excavation detonations and released to the environment may enter a variety of biogeochemical cycles and follow essentially the same transfer pathways as their stable-element counterparts. Estimation of potential internal radiation doses to individuals and/or populations living in or near fallout-contaminated areas requires analysis of the food-chain and other ecological pathways by which radionuclides released to the environment may be returned to man. A generalized materials transfer diagram, applicable to the forest, agricultural, freshwater and marine ecosystems providing food and water to the indigenous population of Panama and Colombia in regions that could be affected by nuclear excavation of a sea-level canal between the Atlantic and Pacific Oceans, is presented. Transfer mechanisms effecting the movement of stable elements and radionuclides in terrestrial ecosystems are discussed, and methods used to simulate these processes by means of mathematical models are described to show how intake values are calculated for different radionuclides in the major ecological pathways leading to man. These data provide a basis for estimating potential internal radiation doses for comparison with the radiation protection criteria established by recognized authorities; and this, in turn, provides a basis for recommending measures to insure the radiological safety of the nuclear operation plan. (author)
Ecological transfer mechanisms - Terrestrial
Energy Technology Data Exchange (ETDEWEB)
Martin, W E; Raines, Gilbert E; Bloom, S G; Levin, A A [Battelle Memorial Institute, CoIumbus, OH (United States)
1969-07-01
Radionuclides produced by nuclear excavation detonations and released to the environment may enter a variety of biogeochemical cycles and follow essentially the same transfer pathways as their stable-element counterparts. Estimation of potential internal radiation doses to individuals and/or populations living in or near fallout-contaminated areas requires analysis of the food-chain and other ecological pathways by which radionuclides released to the environment may be returned to man. A generalized materials transfer diagram, applicable to the forest, agricultural, freshwater and marine ecosystems providing food and water to the indigenous population of Panama and Colombia in regions that could be affected by nuclear excavation of a sea-level canal between the Atlantic and Pacific Oceans, is presented. Transfer mechanisms effecting the movement of stable elements and radionuclides in terrestrial ecosystems are discussed, and methods used to simulate these processes by means of mathematical models are described to show how intake values are calculated for different radionuclides in the major ecological pathways leading to man. These data provide a basis for estimating potential internal radiation doses for comparison with the radiation protection criteria established by recognized authorities; and this, in turn, provides a basis for recommending measures to insure the radiological safety of the nuclear operation plan. (author)
Dissipative quantum dynamics and nonlinear sigma-model
International Nuclear Information System (INIS)
Tarasov, V.E.
1992-01-01
Sedov variational principle which is the generalization of the least action principle for the dissipative and irreversible processes and the classical dissipative mechanics in the phase space is considered. Quantum dynamics for the dissipative and irreversible processes is constructed. As an example of the dissipative quantum theory the nonlinear two-dimensional sigma-model is considered. The conformal anomaly of the energy momentum tensor trace for closed bosonic string on the affine-metric manifold is investigated. The two-loop metric beta-function for nonlinear dissipative sigma-model was calculated. The results are compared with the ultraviolet two-loop conterterms for affine-metric sigma model. 71 refs
On the phase lag of turbulent dissipation in rotating tidal flows
Zhang, Qianjiang; Wu, Jiaxue
2018-03-01
Field observations of rotating tidal flows in a shallow tidally swept sea reveal that a notable phase lag of both shear production and turbulent dissipation increases with height above the seafloor. These vertical delays of turbulent quantities are approximately equivalent in magnitude to that of squared mean shear. The shear production approximately equals turbulent dissipation over the phase-lag column, and thus a main mechanism of phase lag of dissipation is mean shear, rather than vertical diffusion of turbulent kinetic energy. By relating the phase lag of dissipation to that of the mean shear, a simple formulation with constant eddy viscosity is developed to describe the phase lag in rotating tidal flows. An analytical solution indicates that the phase lag increases linearly with height subjected to a combined effect of tidal frequency, Coriolis parameter and eddy viscosity. The vertical diffusion of momentum associated with eddy viscosity produces the phase lag of squared mean shear, and resultant delay of turbulent quantities. Its magnitude is inhibited by Earth's rotation. Furthermore, a theoretical formulation of the phase lag with a parabolic eddy viscosity profile can be constructed. A first-order approximation of this formulation is still a linear function of height, and its magnitude is approximately 0.8 times that with constant viscosity. Finally, the theoretical solutions of phase lag with realistic viscosity can be satisfactorily justified by realistic phase lags of dissipation.
An estimate of energy dissipation due to soil-moisture hysteresis
McNamara, H.
2014-01-01
Processes of infiltration, transport, and outflow in unsaturated soil necessarily involve the dissipation of energy through various processes. Accounting for these energetic processes can contribute to modeling hydrological and ecological systems. The well-documented hysteretic relationship between matric potential and moisture content in soil suggests that one such mechanism of energy dissipation is associated with the cycling between wetting and drying processes, but it is challenging to estimate the magnitude of the effect in situ. The Preisach model, a generalization of the Independent Domain model, allows hysteresis effects to be incorporated into dynamical systems of differential equations. Building on earlier work using such systems with field data from the south-west of Ireland, this work estimates the average rate of hysteretic energy dissipation. Through some straightforward assumptions, the magnitude of this rate is found to be of O(10-5) W m-3. Key Points Hysteresis in soil-water dissipates energy The rate of dissipation can be estimated directly from saturation data The rate of heating caused is significant ©2013. American Geophysical Union. All Rights Reserved.
Research on Heat Dissipation of Electric Vehicle Based on Safety Architecture Optimization
Zhou, Chao; Guo, Yajuan; Huang, Wei; Jiang, Haitao; Wu, Liwei
2017-10-01
In order to solve the problem of excessive temperature in the discharge process of lithium-ion battery and the temperature difference between batteries, a heat dissipation of electric vehicle based on safety architecture optimization is designed. The simulation is used to optimize the temperature field of the heat dissipation of the battery. A reasonable heat dissipation control scheme is formulated to achieve heat dissipation requirements. The results show that the ideal working temperature range of the lithium ion battery is 20?∼45?, and the temperature difference between the batteries should be controlled within 5?. A cooling fan is arranged at the original air outlet of the battery model, and the two cooling fans work in turn to realize the reciprocating flow. The temperature difference is controlled within 5? to ensure the good temperature uniformity between the batteries of the electric vehicle. Based on the above finding, it is concluded that the heat dissipation design for electric vehicle batteries is safe and effective, which is the most effective methods to ensure battery life and vehicle safety.
Estimation of viscous dissipative stresses induced by a mechanical heart valve using PIV data.
Li, Chi-Pei; Lo, Chi-Wen; Lu, Po-Chien
2010-03-01
Among the clinical complications of mechanical heart valves (MHVs), hemolysis was previously thought to result from Reynolds stresses in turbulent flows. A more recent hypothesis suggests viscous dissipative stresses at spatial scales similar in size to red blood cells may be related to hemolysis in MHVs, but the resolution of current instrumentation is insufficient to measure the smallest eddy sizes. We studied the St. Jude Medical (SJM) 27 mm valve in the aortic position of a pulsatile circulatory mock loop under physiologic conditions with particle image velocimetry (PIV). Assuming a dynamic equilibrium assumption between the resolved and sub-grid-scale (SGS) energy flux, the SGS energy flux was calculated from the strain rate tensor computed from the resolved velocity fields and the SGS stress was determined by the Smagorinsky model, from which the turbulence dissipation rate and then the viscous dissipative stresses were estimated. Our results showed Reynolds stresses up to 80 N/m2 throughout the cardiac cycle, and viscous dissipative stresses below 12 N/m2. The viscous dissipative stresses remain far below the threshold of red blood cell hemolysis, but could potentially damage platelets, implying the need for further study in the phenomenon of MHV hemolytic complications.
Theory of dissipative drift instabilities in sheared magnetic fields
International Nuclear Information System (INIS)
Chen, L.; Guzdar, P.N.; Hsu, J.Y.; Kaw, P.K.; Oberman, C.; White, R.
1978-07-01
It is found that in the slab approximation, where usual shear damping is operative, resistivity contributes to an enhancement of this damping and the enhancement factor increases with the electron-ion collision frequency ν/sub ei/. Thus no unstable eigenmodes result. If the shear damping is nullified, either by introducing a strong spatial variation of the density gradient, or by working in toroidal geometry with strong toroidal coupling effects, then unstable eigenmodes with growth rates increasing with ν/sub ei/ are recovered. A perturbation calculation shows that retention of electron temperature fluctuations associated with the mode and inclusion of temperature gradients does not alter these conclusions. Extensive numerical calculations and relation to published experimental results are also presented
A semi-classical treatment of dissipative processes based on Feynman's influence functional method
International Nuclear Information System (INIS)
Moehring, K.; Smilansky, U.
1980-01-01
We develop a semi-classical treatment of dissipative processes based on Feynman's influence functional method. Applying it to deep inelastic collisions of heavy ions we study inclusive transition probabilities corresponding to a situation when only a set of collective variables is specified in the initial and final states. We show that the inclusive probabilities as well as the final energy distributions can be expressed in terms of properly defined classical paths and their corresponding stability fields. We present a uniform approximation for the study of quantal interference and focussing phenomena and discuss the conditions under which they are to be expected. For the dissipation mechanism we study three approximations - the harmonic model for the internal system, the weak coupling (diabatic) and the adiabatic coupling. We show that these three limits can be treated in the same manner. We finally compare the present formalism with other methodes as were introduced for the description of dissipation in deep inelastic collisions. (orig.)
Radio wave dissipation in turbulent auroral plasma during the precipitation of energetic electrons
International Nuclear Information System (INIS)
Mishin, E.V.; Luk'ianova, L.N.; Makarenko, S.F.; Atamaniuk, B.M.
1992-01-01
The results of the theoretical analysis of anomalous (collisionless) radio wave absorption in the turbulent auroral ionosphere during the intrusion of energetic electrons (i.e., in aurorae) are presented. The implications of the plasma turbulent layer (PTL) theory are used. It is shown that the dissipation of radio waves with frequencies much higher than the plasma frequency is caused by the nonlinear (combined) scattering in turbulent plasma of the PTL. In the auroral electrojet layer the principal dissipative process for the radio waves with frequencies close to the plasma frequency is O-Z transformation on the field-aligned, small-scale density fluctuations. The typical dissipation decrements are estimated. 26 refs
A Tractable Estimate for the Dissipation Range Onset Wavenumber Throughout the Heliosphere
Engelbrecht, N. Eugene; Strauss, R. Du Toit
2018-04-01
The modulation of low-energy electrons in the heliosphere is extremely sensitive to the behavior of the dissipation range slab turbulence. The present study derives approximate expressions for the wavenumber at which the dissipation range on the slab turbulence power spectrum commences, by assuming that this onset occurs when dispersive waves propagating parallel to the background magnetic field gyroresonate with thermal plasma particles. This assumption yields results in reasonable agreement with existing spacecraft observations. These expressions are functions of the solar wind proton and electron temperatures, which are here modeled throughout the region where the solar wind is supersonic using a two-component turbulence transport model. The results so acquired are compared with extrapolations of existing models for the dissipation range onset wavenumber, and conclusions are drawn therefrom.
Fluctuation-dissipation theorem in general relativity and the cosmological constant
International Nuclear Information System (INIS)
Mottola, E.
1992-01-01
Vacuum fluctuations are an essential feature of quantum field theory. Yet, the smallness of the scalar curvature of our universe suggests that the zero-point energy associated with these fluctuations does not curve spacetime. A possible way out of this paradox is suggested by the fact that microscopic fluctuations are generally accompanied by dissipative behavior in macroscopic systems. The intimate relation between the two is expressed by a fluctuation-dissipation theorem which extends to general relativity. The connection between quantum fluctuations and dissipation suggests a mechanism for the conversion of coherent stresses in the curvature of space into ordinary matter or radiation, thereby relaxing the effective cosmological ''constant'' to zero over time. The expansion of the universe may be the effect of this time-asymmetric relaxation process
Considering human exposure to pesticides in food products: Importance of dissipation dynamics
DEFF Research Database (Denmark)
Fantke, Peter; Juraske, Ronnie; Jolliet, Olivier
2014-01-01
The general public is continuously concerned about effects from pesticide exposure via residues in food crops. However, impacts from pesticide exposure are mostly neglected in food product-related LCAs. Time-to-harvest and dissipation from crops mainly drive residue dynamics with dissipation...... as most uncertain aspect in characterization modeling. We analyzed measured half-lives (n=4513) with 95% falling between 0.6 and 29 days. With ~500 pesticides authorized alone in the EU for several hundred crops, however, experimental stud-ies only cover few possible pesticide-crop combinations. Therefore......, we estimated dissipation from measured data and provide reference half-lives for 333 pesticides applied at 20°C under field conditions. Our framework allows for detailed explorations of dietary choices in LCA with respect to human health impacts from pesticide exposure via crop consumption. The next...
Aquatic and Terrestrial Environment 2004
DEFF Research Database (Denmark)
Andersen, J. M.; Boutrup, S.; Bijl, L. van der
This report presents the 2004 results of the Danish National Monitoring and Assess-ment Programme for the Aquatic and Terrestrial Environments (NOVANA). 2004 was the first year in which terrestrial nature was included in the monitoring pro-gramme. The report reviews the state of the groundwater......, watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected...
Terrestrial gamma ray flash production by active lightning leader channels
İnan, Umran Savaş; Carlson, B. E.; Lehtinen, N. G.
2017-01-01
The production of terrestrial gamma ray flashes (TGFs) requires a seed energetic electron source and a strong electric field. Lightning leaders naturally provide seed electrons by cold runaway and strong electric fields by charge accumulation on the channel. We model possible TGF production in such fields by simulating the charges and currents on the channel. The resulting electric fields then drive simulations of runaway relativistic electron avalanche and photon emission. Photon spectra and...
Derivation of exact master equation with stochastic description: dissipative harmonic oscillator.
Li, Haifeng; Shao, Jiushu; Wang, Shikuan
2011-11-01
A systematic procedure for deriving the master equation of a dissipative system is reported in the framework of stochastic description. For the Caldeira-Leggett model of the harmonic-oscillator bath, a detailed and elementary derivation of the bath-induced stochastic field is presented. The dynamics of the system is thereby fully described by a stochastic differential equation, and the desired master equation would be acquired with statistical averaging. It is shown that the existence of a closed-form master equation depends on the specificity of the system as well as the feature of the dissipation characterized by the spectral density function. For a dissipative harmonic oscillator it is observed that the correlation between the stochastic field due to the bath and the system can be decoupled, and the master equation naturally results. Such an equation possesses the Lindblad form in which time-dependent coefficients are determined by a set of integral equations. It is proved that the obtained master equation is equivalent to the well-known Hu-Paz-Zhang equation based on the path-integral technique. The procedure is also used to obtain the master equation of a dissipative harmonic oscillator in time-dependent fields.
Energy Technology Data Exchange (ETDEWEB)
Gonçalves, L.A.; Olavo, L.S.F., E-mail: olavolsf@gmail.com
2017-05-15
Dissipation in Quantum Mechanics took some time to become a robust field of investigation after the birth of the field. The main issue hindering developments in the field is that the Quantization process was always tightly connected to the Hamiltonian formulation of Classical Mechanics. In this paper we present a quantization process that does not depend upon the Hamiltonian formulation of Classical Mechanics (although still departs from Classical Mechanics) and thus overcome the problem of finding, from first principles, a completely general Schrödinger equation encompassing dissipation. This generalized process of quantization is shown to be nothing but an extension of a more restricted version that is shown to produce the Schrödinger equation for Hamiltonian systems from first principles (even for Hamiltonian velocity dependent potential). - Highlights: • A Quantization process independent of the Hamiltonian formulation of quantum Mechanics is proposed. • This quantization method is applied to dissipative or absorptive systems. • A Dissipative Schrödinger equation is derived from first principles.
Inferring energy dissipation from violation of the fluctuation-dissipation theorem
Wang, Shou-Wen
2018-05-01
The Harada-Sasa equality elegantly connects the energy dissipation rate of a moving object with its measurable violation of the Fluctuation-Dissipation Theorem (FDT). Although proven for Langevin processes, its validity remains unclear for discrete Markov systems whose forward and backward transition rates respond asymmetrically to external perturbation. A typical example is a motor protein called kinesin. Here we show generally that the FDT violation persists surprisingly in the high-frequency limit due to the asymmetry, resulting in a divergent FDT violation integral and thus a complete breakdown of the Harada-Sasa equality. A renormalized FDT violation integral still well predicts the dissipation rate when each discrete transition produces a small entropy in the environment. Our study also suggests a way to infer this perturbation asymmetry based on the measurable high-frequency-limit FDT violation.
Dynamics of dissipative systems and computational physics
International Nuclear Information System (INIS)
Adam, Gh.; Scutaru, H.; Ixaru, L.; Adam, S.; Rizea, M.; Stefanescu, E.; Mihalache, D.; Mazilu, D.; Crasovan, L.
2002-01-01
During the first year of research activity in the frame of this project there have been investigated two main topics: I. Dynamics of systems of fermions in complex dissipative media; II. Solitons with topologic charge in dissipative systems. An essential problem of the quantum information systems is the controllability and observability of the quantum states, generally described by Lindblad's master equation with phenomenological coefficients. In its usual form, this equation describes a decay of the mean-values, but not necessarily the expected decaying transitions. The basic and very difficult problem of a dissipative quantum theory is to project the evolution of the total system (the system of interest + the environment) on the space of the system of interest. In this case, one obtains a quantum master equation where the system evolution is described by two terms: 1) a Hamiltonian term for the processes with energy conservation, and 2) a non-Hamiltonian term with coefficients depending on the dissipative coupling. That means that a master equation is based on some approximations enabling the replacement of the operators of the dissipative environment with average value coefficients. It is often assumed that the evolution operators of the dissipative system define a semigroup, not a group as in the case of an isolated system. In this framework, Lindblad obtained a quantum master equation in agreement with all the quantum-mechanical principles. However, the Lindblad master equation was unable to secure a correct description of the decaying states. To do that, one has to take into account the transition operators between the system eigenstates with appropriate coefficients. Within this investigation, we have obtained an equation obeying to this requirement, giving the ρ(t) time derivative in terms of creation-annihilation operators of the single-particle states |i>, and λ ij , representing the dissipative coefficients, the microscopic expressions of which are
Observation of plasma toroidal-momentum dissipation by neoclassical toroidal viscosity.
Zhu, W; Sabbagh, S A; Bell, R E; Bialek, J M; Bell, M G; LeBlanc, B P; Kaye, S M; Levinton, F M; Menard, J E; Shaing, K C; Sontag, A C; Yuh, H
2006-06-09
Dissipation of plasma toroidal angular momentum is observed in the National Spherical Torus Experiment due to applied nonaxisymmetric magnetic fields and their plasma-induced increase by resonant field amplification and resistive wall mode destabilization. The measured decrease of the plasma toroidal angular momentum profile is compared to calculations of nonresonant drag torque based on the theory of neoclassical toroidal viscosity. Quantitative agreement between experiment and theory is found when the effect of toroidally trapped particles is included.
Dissipation and residues of emamectin benzoate in cabbage.
Liu, Shuaigang; Zhang, Fengzu; Wang, Lei; Pan, Canping
2012-09-01
Emamectin benzoate residue dynamics and final residues in supervised field trials at GAP conditions were studied. An HPLC-MS analytical method for the determination of emamectin benzoate in cabbage and soil was developed. The recoveries of emamectin benzoate on cabbage and soil were observed from 71% to 102% at fortification levels of 0.01, 0.1 and 1.0 mg/kg. The reported limit of quantification (LOQ) was found to be 0.01 mg/kg. The dissipation experiments showed the half-lives (T(1/2)) of emamectin benzoate was around 1 days. At pre-harvest intervals (PHI) of 7 and 12 days, emamectin benzoate residue was observed to be below the LOQ.
Micellar polymerization: Computer simulations by dissipative particle dynamics.
Shupanov, Ruslan; Chertovich, Alexander; Kos, Pavel
2018-07-15
Nowadays, micellar polymerization is widely used in different fields of industry and research, including modern living polymerization technique. However, this process has many variables and there is no comprehensive model to describe all features. This research presents simulation methodology which describes key properties of such reactions to take a guide through a variety of their modifications. Dissipative particle dynamics is used in addition to Monte Carlo scheme to simulate initiation, propagation, and termination events. Influence of initiation probability and different termination processes on final conversion and molecular-weight distribution are presented. We demonstrate that prolonged initiation leads to increasing in polymer average molecular weight, and surface termination events play major role in conversion limitation, in comparison with recombination. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.
Testing a dissipative kinetic k-essence model
Energy Technology Data Exchange (ETDEWEB)
Cardenas, Victor H.; Villanueva, J.R. [Universidad de Valparaiso, Instituto de Fisica y Astronomia, Valparaiso (Chile); Centro de Astrofisica de Valparaiso, Valparaiso (Chile); Cruz, Norman [Universidad de Santiago de Chile, Departamento de Fisica, Santiago (Chile)
2015-04-01
In thiswork,we present a study of a purely kinetic k-essence model, characterized basically by a parameter α in presence of a bulk dissipative term, whose relationship between viscous pressure Π and energy density ρ of the background follows a polytropic type law, Π ∝ ρ{sup λ+1/2}, where λ, in principle, is a parameter without restrictions. Analytical solutions for the energy density of the k-essence field are found in two specific cases: λ = 1/2 and λ = (1 - α)/2α, and then we show that these solutions possess the same functional form as the non-viscous counterpart. Finally, both approaches are contrasted with observational data from type Ia supernova, and the most recent Hubble parameter measurements, and therefore, the best values for the parameters of the theory are found. (orig.)
Quantum interference and coherent control in dissipative atomic systems
International Nuclear Information System (INIS)
Paspalakis, E.
1999-01-01
In this thesis we study the effects of quantum interference arising from dissipative processes in atomic systems. First, we identify quantum interference phenomena arising from decay mechanisms. Second, we use dynamical methods (the properties of laser fields) to obtain a tailored response of systems in which such interferences are present. We are mainly concerned with two dissipative processes: spontaneous emission and ionization. First, we study the effects of quantum interference arising from spontaneous emission on the population dynamics and the spontaneous emission spectrum of several multi-level systems. Coherent 'phase' control methods for manipulating the response of systems involving spontaneous emission interference are also proposed. Several interesting phenomena are identified such as partial and total quenching of spontaneous emission, phase dependent population dynamics and coherent population trapping. Next, we consider the process of laser-induced continuum structure, where an atom is coupled by two laser fields to the same electronic continuum. An {it ab initio}, non-perturbative study of this process in helium using the R-Matrix Floquet theory is presented. The results of our numerical calculations are compared with those obtained by simple perturbative models and with recent experimental results. The possibility of coherent population transfer via a continuum of states is then analyzed. We study two distinct atomic systems. A laser-induced continuum structure scheme (unstructured continuum) and a bichromatically driven autoionizing scheme (structured continuum). We find that the same conditions which lead to 'dark' states in these systems lead to efficient population transfer. We also identify parameters detrimental to the transfer efficiency and propose methods to overcome them. Finally, we study short pulse propagation in systems involving interfering dissipation mechanisms. We show that the existence of dark states can lead to loss-free and
Time-dependent London approach: Dissipation due to out-of-core normal excitations by moving vortices
Kogan, V. G.
2018-03-01
The dissipative currents due to normal excitations are included in the London description. The resulting time-dependent London equations are solved for a moving vortex and a moving vortex lattice. It is shown that the field distribution of a moving vortex loses its cylindrical symmetry. It experiences contraction that is stronger in the direction of the motion than in the direction normal to the velocity v . The London contribution of normal currents to dissipation is small relative to the Bardeen-Stephen core dissipation at small velocities, but it approaches the latter at high velocities, where this contribution is no longer proportional to v2. To minimize the London contribution to dissipation, the vortex lattice is oriented so as to have one of the unit cell vectors along the velocity. This effect is seen in experiments and predicted within the time-dependent Ginzburg-Landau theory.
Alfven wave absorption in dissipative plasma
International Nuclear Information System (INIS)
Gavrikov, M B; Taiurskii, A A
2017-01-01
We consider nonlinear absorption of Alfven waves due to dissipative effects in plasma and relaxation of temperatures of electrons and ions. This study is based on an exact solution of the equations of two-fluid electromagnetic hydrodynamics (EMHD) of plasma. It is shown that in order to study the decay of Alfven waves, it suffices to examine the behavior of their amplitudes whose evolution is described by a system of ordinary differential equations (ODEs) obtained in this paper. On finite time intervals, the system of equations on the amplitudes is studied numerically, while asymptotic integration (the Hartman-Grobman theorem) is used to examine its large-time behavior. (paper)
Tunneling with dissipation in open quantum systems
International Nuclear Information System (INIS)
Adamyan, G.G.; Antonenko, N.V.; Scheid, W.
1997-01-01
Based on the general form of the master equation for open quantum systems the tunneling is considered. Using the path integral technique a simple closed form expression for the tunneling rate through a parabolic barrier is obtained. The tunneling in the open quantum systems strongly depends on the coupling with environment. We found the cases when the dissipation prohibits tunneling through the barrier but decreases the crossing of the barrier for the energies above the barrier. As a particular application, the case of decay from the metastable state is considered
Dissipative neutrino oscillations in randomly fluctuating matter
International Nuclear Information System (INIS)
Benatti, F.; Floreanini, R.
2005-01-01
The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: It takes into account matter-induced, decoherence phenomena that go beyond the standard Mikheyev-Smirnov-Wolfenstein (MSW) effect. A widely adopted density fluctuation pattern is found to be physically untenable: A more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis
Dissipative neutrino oscillations in randomly fluctuating matter
Benatti, F.; Floreanini, R.
2005-01-01
The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: It takes into account matter-induced, decoherence phenomena that go beyond the standard Mikheyev-Smirnov-Wolfenstein (MSW) effect. A widely adopted density fluctuation pattern is found to be physically untenable: A more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis.
Dissipative Structures At Laser-Solid Interactions
Nanai, Laszlo
1989-05-01
The questions which are discussed in this lecture refer to one of sections of laser-solid interactions, namely: to formation of different dissipative structures on the surface of metals and semiconductors when they are irradiated by intensive laser light in chemically active media (f.e.air). Some particular examples of the development at different spatial and time instabilities, periodic and stochastic structures, auto-wave processes are present-ed using testing materials vanadium metal and semiconducting V205 single crystals and light sources: cw and pulsed CO2 and YAG lasers.
Cumulus convection and the terrestrial water-vapor distribution
Donner, Leo J.
1988-01-01
Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.
Energy conversion and dissipation at dipolarization fronts: Theory, modeling and MMS observations
Sitnov, M. I.; Motoba, T.; Merkin, V. G.; Ohtani, S.; Cohen, I. J.; Mauk, B.; Vines, S. K.; Anderson, B. J.; Moore, T. E.; Torbert, R. B.; Giles, B. L.; Burch, J. L.
2017-12-01
Magnetic reconnection is one of the most important energy conversion mechanisms in space plasmas. In the classical picture it converts the energy of antiparallel magnetic fields into the kinetic and thermal energy of accelerated plasma particles in reconnection exhausts. It also involves energy dissipation near the X-line. This classical picture may be substantially modified in real space plasma configurations, such as the dayside magnetopause and the magnetotail. In particular, in the magnetotail the flows of accelerated particles may be strongly asymmetric along the tail with the domination of earthward flows. At the same time, strong energy conversion and even dissipation may occur away from the X-line, in particular, at dipolarization fronts. Here we present a theoretical picture of spontaneous magnetotail reconnection based on 3-D PIC simulations with the focus on plasma bulk flows, energy conversion and dissipation. This picture is compared with some observations from the MMS tail season. An important finding from these observations is that dipolarizations fronts may not only be regions of the total energy conversion with jE>0, but they may also be the sites of energy dissipation, both positive (jE'>0, E' is the electric field E in the system moving with one of the plasma species) and negative (jE'braking).
Energy Technology Data Exchange (ETDEWEB)
Jawad, Abdul; Rani, Shamaila [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); Hussain, Shahzad [Aspire College, Department of Mathematics, Hafizabad (Pakistan); Videla, Nelson [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile)
2017-10-15
The warm inflation scenario in view of the modified Chaplygin gas is studied. We consider the inflationary expansion to be driven by a standard scalar field whose decay ratio Γ has a generic power-law dependence with the scalar field φ and the temperature of the thermal bath T. By assuming an exponential power-law dependence in the cosmic time for the scale factor a(t), corresponding to the intermediate inflation model, we solve the background and perturbative dynamics considering our model to evolve according to (1) weak dissipative regime and (2) strong dissipative regime. Specifically, we find explicit expressions for the dissipative coefficient, scalar potential, and the relevant inflationary observables like the scalar power spectrum, scalar spectral index, and tensor-to-scalar ratio. The free parameters characterizing our model are constrained by considering the essential condition for warm inflation, the conditions for the model evolves according to weak or strong dissipative regime, and the 2015 Planck results through the n{sub s}-r plane. (orig.)
Ghasemi, M.; Tavassoly, M. K.; Nourmandipour, A.
2017-12-01
In this paper, we investigate the possibility of entanglement swapping between two independent nonperfect cavities consisting of an atom with finite lifetime of atomic levels (as two independent sources of dissipation), which interacts with a quantized electromagnetic field in the presence of detuning and Kerr medium. In fact, there is no direct interaction between the two atoms, therefore, no entanglement exists between them. We use the Bell state measurement performed on the photons leaving the cavities to swap the entanglement stored between the atom-fields in each cavity into atom-atom. Our motivation comes from the fact that two-qubit entangled states are of great interest for quantum information science and technologies. We discuss the effect of the initial state of the system, the detuning parameter, the Kerr medium and the two dissipation sources on the swapped entanglement to atom-atom. We interestingly find that when the atomic decay rates and photonic leakages from the cavities are equal, our system behaves as an ideal system with no dissipation. Our results show that it is possible to create a long-living atom-atom maximally entangled state in the presence of Kerr effect and dissipation; we determine these conditions in detail and also establish the final atom-atom Bell state.
Yen, Jui-Hung; Sheu, Wey-Shin; Wang, Yei-Shung
2003-02-01
The dissipation and mobility of the herbicide oxyfluorfen (2-chloro-alpha,alpha,alpha-trifluoro-p-tolyl 3-ethoxy-4-nitrophenyl ether) in field soil of Taiwan were investigated in the laboratory with six tea garden soils. The dissipation coefficients of oxyfluorfen in soils of different moisture content (30%, 60%, and 90% of soil field capacity) and soil temperature (10 degrees C, 25 degrees C, and 40 degrees C) were studied. Results indicate that the half-life of oxyfluorfen ranged from 72 to 160 days for six tea garden soils. It was found that if the temperature is high, the dissipation rate is rapid, and there is almost no dissipation at 10 degrees C. Possible contamination of groundwater by the herbicide oxyfluorfen was assessed using the behavior assessment model and the groundwater pollution-potential (GWP) model. The results obtained after evaluating the residue and travel time using the GWP model illustrated that oxyfluorfen is not very mobile in soil and may not contaminate groundwater under normal conditions. But in the case of soil of extremely low organic carbon content and coarse texture, oxyfluorfen has the potential to contaminate groundwater less than 3m deep.
Investigation of Numerical Dissipation in Classical and Implicit Large Eddy Simulations
Directory of Open Access Journals (Sweden)
Moutassem El Rafei
2017-12-01
Full Text Available The quantitative measure of dissipative properties of different numerical schemes is crucial to computational methods in the field of aerospace applications. Therefore, the objective of the present study is to examine the resolving power of Monotonic Upwind Scheme for Conservation Laws (MUSCL scheme with three different slope limiters: one second-order and two third-order used within the framework of Implicit Large Eddy Simulations (ILES. The performance of the dynamic Smagorinsky subgrid-scale model used in the classical Large Eddy Simulation (LES approach is examined. The assessment of these schemes is of significant importance to understand the numerical dissipation that could affect the accuracy of the numerical solution. A modified equation analysis has been employed to the convective term of the fully-compressible Navier–Stokes equations to formulate an analytical expression of truncation error for the second-order upwind scheme. The contribution of second-order partial derivatives in the expression of truncation error showed that the effect of this numerical error could not be neglected compared to the total kinetic energy dissipation rate. Transitions from laminar to turbulent flow are visualized considering the inviscid Taylor–Green Vortex (TGV test-case. The evolution in time of volumetrically-averaged kinetic energy and kinetic energy dissipation rate have been monitored for all numerical schemes and all grid levels. The dissipation mechanism has been compared to Direct Numerical Simulation (DNS data found in the literature at different Reynolds numbers. We found that the resolving power and the symmetry breaking property are enhanced with finer grid resolutions. The production of vorticity has been observed in terms of enstrophy and effective viscosity. The instantaneous kinetic energy spectrum has been computed using a three-dimensional Fast Fourier Transform (FFT. All combinations of numerical methods produce a k − 4 spectrum
Salama, Amgad
2013-02-01
Some sort of controversy is associated with the problem of viscous dissipation in saturated porous media for which we try to present a comparison study between the influences of the different terms contributing to this phenomenon. We consider viscous dissipation by studying the case of semi-infinite flat plate embedded in saturated porous medium and is kept at constant, higher temperature compared with the surrounding fluid. The fluid is induced to move upwards by natural convection during which viscous dissipation is considered. The boundary layer assumptions are considered to simplify the treatment and to highlight the influencing parameters. The behavior of temperature, and velocity fields in the neighborhood of the vertical flat plate were used to highlight the effects of these parameters. Three terms were considered to contribute to viscous dissipation, namely Darcy\\'s term, the Forchheimer term and Al-Hadharami\\'s term. Although there are no unanimous agreements between researchers to include the Forchhemier term in the dissipation function, some researchers argued it might have an indirect effect and hence for this sake and for completion purposes, we include it in this comparison study. Dimensional considerations reveal that Darcy\\'s term is influenced by Gebhart number, the Forchheimer term is controlled by the non-Darcy parameter and Al-Hadharami\\'s term is influenced by Darcy\\'s number. The governing, non-dimensional set of equations together with the imposed boundary conditions is numerically investigated by finite element method. The results for the details of the governing parameters are presented and investigated. It is found that the irreversible process of transforming the kinetic energy of the moving fluid to heat energy via the viscosity of the moving fluid (i.e., viscous dissipation) is very much influenced by the relative magnitude of these dimensionless parameters. © 2012 Elsevier Masson SAS. All rights reserved.
Morrison, James W., Ed.; Hall, James A., Ed.
This collection of study units focuses on the study of the ecology of land habitats. Considered are such topics as map reading, field techniques, forest ecosystem, birds, insects, small mammals, soils, plant ecology, preparation of terrariums, air pollution, photography, and essentials of an environmental studies program. Each unit contains…
Semiclassical evolution of dissipative Markovian systems
International Nuclear Information System (INIS)
Ozorio de Almeida, A M; Rios, P de M; Brodier, O
2009-01-01
A semiclassical approximation for an evolving density operator, driven by a 'closed' Hamiltonian operator and 'open' Markovian Lindblad operators, is obtained. The theory is based on the chord function, i.e. the Fourier transform of the Wigner function. It reduces to an exact solution of the Lindblad master equation if the Hamiltonian operator is a quadratic function and the Lindblad operators are linear functions of positions and momenta. Initially, the semiclassical formulae for the case of Hermitian Lindblad operators are reinterpreted in terms of a (real) double phase space, generated by an appropriate classical double Hamiltonian. An extra 'open' term is added to the double Hamiltonian by the non-Hermitian part of the Lindblad operators in the general case of dissipative Markovian evolution. The particular case of generic Hamiltonian operators, but linear dissipative Lindblad operators, is studied in more detail. A Liouville-type equivariance still holds for the corresponding classical evolution in double phase space, but the centre subspace, which supports the Wigner function, is compressed, along with expansion of its conjugate subspace, which supports the chord function. Decoherence narrows the relevant region of double phase space to the neighbourhood of a caustic for both the Wigner function and the chord function. This difficulty is avoided by a propagator in a mixed representation, so that a further 'small-chord' approximation leads to a simple generalization of the quadratic theory for evolving Wigner functions
Dissipative time-dependent quantum transport theory.
Zhang, Yu; Yam, Chi Yung; Chen, GuanHua
2013-04-28
A dissipative time-dependent quantum transport theory is developed to treat the transient current through molecular or nanoscopic devices in presence of electron-phonon interaction. The dissipation via phonon is taken into account by introducing a self-energy for the electron-phonon coupling in addition to the self-energy caused by the electrodes. Based on this, a numerical method is proposed. For practical implementation, the lowest order expansion is employed for the weak electron-phonon coupling case and the wide-band limit approximation is adopted for device and electrodes coupling. The corresponding hierarchical equation of motion is derived, which leads to an efficient and accurate time-dependent treatment of inelastic effect on transport for the weak electron-phonon interaction. The resulting method is applied to a one-level model system and a gold wire described by tight-binding model to demonstrate its validity and the importance of electron-phonon interaction for the quantum transport. As it is based on the effective single-electron model, the method can be readily extended to time-dependent density functional theory.
Hydrodynamic relaxations in dissipative particle dynamics
Hansen, J. S.; Greenfield, Michael L.; Dyre, Jeppe C.
2018-01-01
This paper studies the dynamics of relaxation phenomena in the standard dissipative particle dynamics (DPD) model [R. D. Groot and P. B. Warren, J. Chem. Phys. 107, 4423 (1997)]. Using fluctuating hydrodynamics as the framework of the investigation, we focus on the collective transverse and longitudinal dynamics. It is shown that classical hydrodynamic theory predicts the transverse dynamics at relatively low temperatures very well when compared to simulation data; however, the theory predictions are, on the same length scale, less accurate for higher temperatures. The agreement with hydrodynamics depends on the definition of the viscosity, and here we find that the transverse dynamics are independent of the dissipative and random shear force contributions to the stress. For high temperatures, the spectrum for the longitudinal dynamics is dominated by the Brillouin peak for large length scales and the relaxation is therefore governed by sound wave propagation and is athermal. This contrasts the results at lower temperatures and small length scale, where the thermal process is clearly present in the spectra. The DPD model, at least qualitatively, re-captures the underlying hydrodynamical mechanisms, and quantitative agreement is excellent at intermediate temperatures for the transverse dynamics.
Hyperbolic theory of relativistic conformal dissipative fluids
Lehner, Luis; Reula, Oscar A.; Rubio, Marcelo E.
2018-01-01
We develop a complete description of the class of conformal relativistic dissipative fluids of divergence form, following the formalism described in [R. Geroch and L. Lindblom, Phys. Rev. D 41, 1855 (1990), 10.1103/PhysRevD.41.1855, S. Pennisi, Some considerations on a non linear approach to extended thermodynamics and in Proceedings of Symposium of Kinetic Theory and Extended Thermodynamics, Bologna, 1987.]. This type of theory is fully described in terms of evolution variables whose dynamics are governed by total divergence-type conservation laws. Specifically, we give a characterization of the whole family of conformal fluids in terms of a single master scalar function defined up to second-order corrections in dissipative effects, which we explicitly find in general form. This allows us to identify the equilibrium states of the theory and derive constitutive relations and a Fourier-like law for the corresponding first-order theory heat flux. Finally, we show that among this class of theories—and near equilibrium configurations—there exist symmetric hyperbolic ones, implying that for them one can define well-posed initial value problems.
International Nuclear Information System (INIS)
Borderie, B.; Rivet, M.F.; Tassan-Got, L.
1990-01-01
For several years a new field in nuclear physics has been opened by the opportunity to accelerate heavy ions through an energy domain including the Fermi energy of nucleons. This new domain has to be seen as a link between dissipative processes observed at low energies, dominated by mean field considerations, and high energy collisions for which nucleon-nucleon collisions play an important role. This paper reviews our present knowledge on peripheral collisions. A reminder of contiguous energy domains is done as well as their extension in the new field. Specific calculations are also presented. Finally a wide comparison between experiments and calculations is performed. A fast dissipative stage proves to be responsible for the dominant mechanisms involved, at least when the incident energy is lower than 50 MeV/nucleon
Dissipation of oxytetracycline in soils under different redox conditions
International Nuclear Information System (INIS)
Yang Jigeng; Ying Guangguo; Zhou Lijun; Liu Shan; Zhao Jianliang
2009-01-01
This study investigated the dissipation kinetics of oxytetracycline in soils under aerobic and anoxic conditions. Laboratory experiments showed that the dissipation of oxytetracycline in soil followed first-order reaction kinetics and its dissipation rates decreased with increasing concentration. Oxytetracycline dissipated faster in soil under aerobic conditions than under anoxic conditions. The half-lives for oxytetracycline in soil under aerobic conditions ranged between 29 and 56 days for non-sterile treatments and 99-120 days for sterile treatments, while under anoxic conditions the half-lives of oxytetracycline ranged between 43 and 62 days in the non-sterile soil and between 69 and 104 days in the sterile soil. This suggests microbes can degrade oxytetracycline in agricultural soil. Abiotic factors such as strong sorption onto soil components also played a role in the dissipation of oxytetracycline in soil. - Oxytetracycline dissipation in soils is influenced by redox conditions and soil properties.
Dissipation of oxytetracycline in soils under different redox conditions
Energy Technology Data Exchange (ETDEWEB)
Jigeng, Yang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Department of Chemistry and Chemical Engineering, Hunan University of Arts and Sciences, Changde 415000 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Lijun, Zhou; Shan, Liu; Jianliang, Zhao [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China)
2009-10-15
This study investigated the dissipation kinetics of oxytetracycline in soils under aerobic and anoxic conditions. Laboratory experiments showed that the dissipation of oxytetracycline in soil followed first-order reaction kinetics and its dissipation rates decreased with increasing concentration. Oxytetracycline dissipated faster in soil under aerobic conditions than under anoxic conditions. The half-lives for oxytetracycline in soil under aerobic conditions ranged between 29 and 56 days for non-sterile treatments and 99-120 days for sterile treatments, while under anoxic conditions the half-lives of oxytetracycline ranged between 43 and 62 days in the non-sterile soil and between 69 and 104 days in the sterile soil. This suggests microbes can degrade oxytetracycline in agricultural soil. Abiotic factors such as strong sorption onto soil components also played a role in the dissipation of oxytetracycline in soil. - Oxytetracycline dissipation in soils is influenced by redox conditions and soil properties.
If there is dissipation the particle can gain energy
International Nuclear Information System (INIS)
De Carvalho, R Egydio
2015-01-01
In this work, we summarize two different mechanisms to gain energy from the presence of dissipation in a time-dependent non-linear system. The particles can gain energy, in the average, from two different scenarios: i) for very week dissipation with the creation of an attractor with high velocity, and ii) in the opposite limit, for very strong dissipation, the particles can also gain energy from a boundary crisis. From the thermodynamic viewpoint both results are totally acceptable. (paper)
Effective mass approximation for tunneling states with dissipation
International Nuclear Information System (INIS)
Chen Hong; Wu Xiang.
1987-08-01
The dissipative tunneling in an asymmetric double-well potential is studied at low temperature. With effective mass approximation, the dissipation can be replaced by a temperature-dependent effective mass. The effective mass increases with decreasing temperature and becomes infinite at T=0. The partition function of the system is derived, which has the same form as that of a non-dissipative tunneling system. Some possible applications in glasses and heavy fermion system are also discussed. (author). 21 refs, 1 fig
On Maximally Dissipative Shock Waves in Nonlinear Elasticity
Knowles, James K.
2010-01-01
Shock waves in nonlinearly elastic solids are, in general, dissipative. We study the following question: among all plane shock waves that can propagate with a given speed in a given one-dimensional nonlinearly elastic bar, which one—if any—maximizes the rate of dissipation? We find that the answer to this question depends strongly on the qualitative nature of the stress-strain relation characteristic of the given material. When maximally dissipative shocks do occur, they propagate according t...
The Fluctuation Theorem and Dissipation Theorem for Poiseuille Flow
International Nuclear Information System (INIS)
Brookes, Sarah J; Reid, James C; Evans, Denis J; Searles, Debra J
2011-01-01
The fluctuation theorem and the dissipation theorem provide relationships to describe nonequilibrium systems arbitrarily far from, or close to equilibrium. They both rely on definition of a central property, the dissipation function. In this manuscript we apply these theorems to examine a boundary thermostatted system undergoing Poiseuille flow. The relationships are verified computationally and show that the dissipation theorem is potentially useful for study of boundary thermostatted systems consisting of complex molecules undergoing flow in the nonlinear regime.
Universality in driven-dissipative quantum many-body systems
International Nuclear Information System (INIS)
Sieberer, L.M.
2015-01-01
Recent experimental investigations of condensation phenomena in driven-dissipative quantum many-body systems raise the question of what kind of novel universal behavior can emerge under non-equilibrium conditions. We explore various aspects of universality in this context. Our results are of relevance for a variety of open quantum systems on the interface of quantum optics and condensed matter physics, ranging from exciton-polariton condensates to cold atomic gases. In Part I we characterize the dynamical critical behavior at the Bose-Einstein condensation phase transition in driven open quantum systems in three spatial dimensions. Although thermodynamic equilibrium conditions are emergent at low frequencies, the approach to this thermalized low-frequency regime is described by a critical exponent which is specific to the non-equilibrium transition, and places the latter beyond the standard classification of equilibrium dynamical critical behavior. Our theoretical approach is based on the functional renormalization group within the framework of Keldysh non-equilibrium field theory, which is equivalent to a microscopic description of the open system dynamics in terms of a many-body quantum master equation. Universal behavior in the coherence properties of driven-dissipative condensates in reduced dimensions is investigated in Part II. We show that driven two-dimensional Bose systems cannot exhibit algebraic order as in thermodynamic equilibrium, unless they are sufficiently anisotropic. However, we find evidence that even isotropic systems may have a finite superfluidity fraction. In one-dimensional systems, non-equilibrium conditions are traceable in the behavior of the autocorrelation function. We obtain these results by mapping the long-wavelength condensate dynamics onto the Kardar-Parisi-Zhang equation. In Part III we show that systems in thermodynamic equilibrium have a specific symmetry, which makes them distinct from generic driven open systems. The novel
Quantum dissipation and decoherence of collective excitations in metallic nanoparticles
Energy Technology Data Exchange (ETDEWEB)
Weick, G.
2006-09-22
The treatment of the surface plasmon as a quantum particle provides a model system for the study of decoherence and quantum dissipation in confined nanoscopic systems, where the role of the electronic correlations is preponderant. Throughout this work we treat the metallic nanoparticle in the jellium approximation where the ionic structure is replaced by a continuous and homogeneous positive charge. The external laser field puts the center of mass into a coherent superposition of its ground and first excited state and thus creates a surface plasmon. The coupling between the center of mass and the relative coordinates causes decoherence and dissipation of this collective excitation. We have developed a theoretical formalism well adapted to the study of this dissipation, which is the reduced-density-matrix formalism. There are mainly two parameters which govern the surface plasmon dynamics: the decay rate of the plasmon, and the resonance frequency. For sizes smaller than 1 nm, presents oscillations as a function of the size. By means of a semiclassical formalism using Gutzwiller's trace formula for the density of states, we have shown that those oscillations are due to the correlations of the density of states of the particles and holes in the nanoparticle. If one considers a noble-metal nanoparticle in an inert matrix, we have shown that a naive application of the Kubo formula for the surface plasmon linewidth fails to reproduce the TDLDA numerical results, which are however consistent with experimental results. We have modified the Kubo theory in order to solve this discrepancy. We have shown, by extending our semiclassical theory to the nonlinear case, that the double plasmon is indeed well defined. We have calculated the lifetime of the double plasmon associated to this second-order effect. In addition to the width, we have also addressed the value of the resonance frequency. The classical electromagnetic Mie theory gives for the resonance frequency of the
Dissipation Assisted Quantum Memory with Coupled Spin Systems
Jiang, Liang; Verstraete, Frank; Cirac, Ignacio; Lukin, Mikhail
2009-05-01
Dissipative dynamics often destroys quantum coherences. However, one can use dissipation to suppress decoherence. A well-known example is the so-called quantum Zeno effect, in which one can freeze the evolution using dissipative processes (e.g., frequently projecting the system to its initial state). Similarly, the undesired decoherence of quantum bits can also be suppressed using controlled dissipation. We propose and analyze the use of this generalization of quantum Zeno effect for protecting the quantum information encoded in the coupled spin systems. This new approach may potentially enhance the performance of quantum memories, in systems such as nitrogen-vacancy color-centers in diamond.
Entropy model of dissipative structure on corporate social responsibility
Li, Zuozhi; Jiang, Jie
2017-06-01
Enterprise is prompted to fulfill the social responsibility requirement by the internal and external environment. In this complex system, some studies suggest that firms have an orderly or chaotic entropy exchange behavior. Based on the theory of dissipative structure, this paper constructs the entropy index system of corporate social responsibility(CSR) and explores the dissipative structure of CSR through Brusselator model criterion. Picking up listed companies of the equipment manufacturing, the research shows that CSR has positive incentive to negative entropy and promotes the stability of dissipative structure. In short, the dissipative structure of CSR has a positive impact on the interests of stakeholders and corporate social images.
Utilization of the terrestrial cyanobacteria
Katoh, Hiroshi; Tomita-Yokotani, Kaori; Furukawa, Jun; Kimura, Shunta; Yokoshima, Mika; Yamaguchi, Yuji; Takenaka, Hiroyuki
The terrestrial, N _{2}-fixing cyanobacterium, Nostoc commune has expected to utilize for agriculture, food and terraforming cause of its extracellular polysaccharide, desiccation tolerance and nitrogen fixation. Previously, the first author indicated that desiccation related genes were analyzed and the suggested that the genes were related to nitrogen fixation and metabolisms. In this report, we suggest possibility of agriculture, using the cyanobacterium. Further, we also found radioactive compounds accumulated N. commune (cyanobacterium) in Fukushima, Japan after nuclear accident. Thus, it is investigated to decontaminate radioactive compounds from the surface soil by the cyanobacterium and showed to accumulate radioactive compounds using the cyanobacterium. We will discuss utilization of terrestrial cyanobacteria under closed environment. Keyword: Desiccation, terrestrial cyanobacteria, bioremediation, agriculture
Dissipation of 'dark energy' by cortex in knowledge retrieval.
Capolupo, Antonio; Freeman, Walter J; Vitiello, Giuseppe
2013-03-01
We have devised a thermodynamic model of cortical neurodynamics expressed at the classical level by neural networks and at the quantum level by dissipative quantum field theory. Our model is based on features in the spatial images of cortical activity newly revealed by high-density electrode arrays. We have incorporated the mechanism and necessity for so-called dark energy in knowledge retrieval. We have extended the model first using the Carnot cycle to define our measures for energy, entropy and temperature, and then using the Rankine cycle to incorporate criticality and phase transitions. We describe the dynamics of two interactive fields of neural activity that express knowledge, one at high and the other at low energy density, and the two operators that create and annihilate the fields. We postulate that the extremely high density of energy sequestered briefly in cortical activity patterns can account for the vividness, richness of associations, and emotional intensity of memories recalled by stimuli. Copyright © 2013 Elsevier B.V. All rights reserved.
Grazing livestock are exposed to terrestrial cyanobacteria.
McGorum, Bruce C; Pirie, R Scott; Glendinning, Laura; McLachlan, Gerry; Metcalf, James S; Banack, Sandra A; Cox, Paul A; Codd, Geoffrey A
2015-02-25
While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in all samples tested, including 6 plant washings, 1 soil sample and ileal contents from 2 grazing horses. Further work was performed to test the hypothesis that ingestion of cyanotoxins contributes to the pathogenesis of some currently unexplained diseases of grazing horses, including equine grass sickness (EGS), equine motor neuron disease (EMND) and hepatopathy. Phormidium population density was significantly higher on EGS fields than on control fields. The cyanobacterial neurotoxic amino acid 2,4-diaminobutyric acid (DAB) was detected in plant washings from EGS fields, but worst case scenario estimations suggested the dose would be insufficient to cause disease. Neither DAB nor the cyanobacterial neurotoxins β-N-methylamino-L-alanine and N-(2-aminoethyl) glycine were detected in neural tissue from 6 EGS horses, 2 EMND horses and 7 control horses. Phormidium was present in low numbers on plants where horses had unexplained hepatopathy. This study did not yield evidence linking known cyanotoxins with disease in grazing horses. However, further study is warranted to identify and quantify toxins produced by cyanobacteria on livestock fields, and determine whether, under appropriate conditions, known or unknown cyanotoxins contribute to currently unexplained diseases in grazing livestock.
Community Decadal Panel for Terrestrial Analogs to Mars
Barlow, N. G.; Farr, T.; Baker, V. R.; Bridges, N.; Carsey, F.; Duxbury, N.; Gilmore, M. S.; Green, J. R.; Grin, E.; Hansen, V.; Keszthelyi, L.; Lanagan, P.; Lentz, R.; Marinangeli, L.; Morris, P. A.; Ori, G. G.; Paillou, P.; Robinson, C.; Thomson, B.
2001-11-01
It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites for Mars, instrument tests, laboratory measurements (including analysis of martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel is considering the following two key questions: (1) How do terrestrial analog studies tie in to the MEPAG science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel is considering the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.
Terrestrial Sagnac delay constraining modified gravity models
Karimov, R. Kh.; Izmailov, R. N.; Potapov, A. A.; Nandi, K. K.
2018-04-01
Modified gravity theories include f(R)-gravity models that are usually constrained by the cosmological evolutionary scenario. However, it has been recently shown that they can also be constrained by the signatures of accretion disk around constant Ricci curvature Kerr-f(R0) stellar sized black holes. Our aim here is to use another experimental fact, viz., the terrestrial Sagnac delay to constrain the parameters of specific f(R)-gravity prescriptions. We shall assume that a Kerr-f(R0) solution asymptotically describes Earth's weak gravity near its surface. In this spacetime, we shall study oppositely directed light beams from source/observer moving on non-geodesic and geodesic circular trajectories and calculate the time gap, when the beams re-unite. We obtain the exact time gap called Sagnac delay in both cases and expand it to show how the flat space value is corrected by the Ricci curvature, the mass and the spin of the gravitating source. Under the assumption that the magnitude of corrections are of the order of residual uncertainties in the delay measurement, we derive the allowed intervals for Ricci curvature. We conclude that the terrestrial Sagnac delay can be used to constrain the parameters of specific f(R) prescriptions. Despite using the weak field gravity near Earth's surface, it turns out that the model parameter ranges still remain the same as those obtained from the strong field accretion disk phenomenon.
Directory of Open Access Journals (Sweden)
Brad J. Arnold
2014-07-01
Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.
Soil and terrestrial biology studies
International Nuclear Information System (INIS)
Anon.
1976-01-01
Soil and terrestrial biology studies focused on developing an understanding of the uptake of gaseous substances from the atmosphere by plants, biodegradation of oil, and the movement of Pu in the terrestrial ecosystems of the southeastern United States. Mathematical models were developed for SO 2 and tritium uptake from the atmosphere by plants; the uptake of tritium by soil microorganisms was measured; and the relationships among the Pu content of soil, plants, and animals of the Savannah River Plant area were studied. Preliminary results are reported for studies on the biodegradation of waste oil on soil surfaces
Structure of the terrestrial planets
International Nuclear Information System (INIS)
Lyttleton, R.A.
1977-01-01
Recent reviews (cf. Runcorn, 1968; or Cook, 1972, 1975) on the structure of the planets omit reference to the phase-change hypothesis for the nature of the terrestrial core, despite that numerous prior predictions of the theory based on this hypothesis have subsequently been borne out as correct. These reviews also ignore the existence of theoretical calculations of the internal structure of Venus which can be computed with high accuracy by use of the terrestrial seismic data. Several examples of numerous mistakes committed in these reviews are pointed out. (Auth.)
Priapism caused by 'Tribulus terrestris'.
Campanelli, M; De Thomasis, R; Tenaglia, R L
2016-01-01
A 36-year-old Caucasian man was diagnosed with a 72-h-lasting priapism that occurred after the assumption of a Herbal supplement based on Tribulus terrestris, which is becoming increasingly popular for the treatment of sexual dysfunction. The patient underwent a cavernoglandular shunt (Ebbehoj shunt) in order to obtain complete detumescence, from which derived negative post-episode outcomes on sexual function. All patients consuming non-FDA-approved alternative supplements such as Tribulus terrestris should be warned about the possible serious side effects.
Radionuclides in terrestrial ecosystems
International Nuclear Information System (INIS)
Howard, B.J.; Kennedy, V.H.; Nelson, A.
1983-06-01
A bibliographical database has been developed to provide quick access to research and background literature in the field of radioecology. This is a development of an earlier database described by Nelson (Bocock 1981). ITE's particular fields of interest have led to a subject bias in the bibliography towards studies in Cumbria, especially those concerned with radionuclides originating from the reprocessing plant at Sellafield, and towards ecological research studies that are complementary to radionuclide studies. Other subjects covered, include the chemistry of radionuclides, budgets and transfers within ecosystems and techniques for the analysis of environmental samples. ITE's research objectives have led to the establishment of a specialized database which is intended to complement rather than compete with the large international databases made available by suppliers such as IRS-DIALTECH or DIALOG. Currently the database holds about 1900 references which are stored on a 2 1/2 megabyte hard disk on a Digital PDP11/34 computer operating under a time shared system. The references follow a standard format. (author)
Quantum thermodynamics for driven dissipative bosonic systems
Ochoa, Maicol A.; Zimbovskaya, Natalya; Nitzan, Abraham
2018-02-01
We investigate two prototypical dissipative bosonic systems under slow driving and arbitrary system-bath coupling strength, recovering their dynamic evolution as well as the heat and work rates, and we verify that thermodynamic laws are respected. Specifically, we look at the damped harmonic oscillator and the damped two-level system. For the former, we study independently the slow time-dependent perturbation in the oscillator frequency and in the coupling strength. For the latter, we concentrate on the slow modulation of the energy gap between the two levels. Importantly, we are able to find the entropy production rates for each case without explicitly defining nonequilibrium extensions for the entropy functional. This analysis also permits the definition of phenomenological friction coefficients in terms of structural properties of the system-bath composite.
An extended dissipative particle dynamics model
Cotter, C J
2003-01-01
The method of dissipative particle dynamics (DPD) was introduced by Hoogerbrugge & Koelman to study meso-scale material processes. The theoretical investigation of the DPD method was initiated by Espanol who used a Fokker-Planck formulation of the DPD method and applied the Mori-Zwanzig projection operator calculus to obtain the equations of hydrodynamics for DPD. A current limitation of DPD is that it requires a clear separation of scales between the resolved and unresolved processes. In this note, we suggest a simple extension of DPD that allows for inclusion of unresolved processes with exponentially decaying variance for any value of the decay rate. The main point of the extension is that it is as easy to implement as DPD in a numerical algorithm.
Dissipative dynamics of superconducting hybrid qubit systems
International Nuclear Information System (INIS)
Montes, Enrique; Calero, Jesus M; Reina, John H
2009-01-01
We perform a theoretical study of composed superconducting qubit systems for the case of a coupled qubit configuration based on a hybrid qubit circuit made of both charge and phase qubits, which are coupled via a σ x x σ z interaction. We compute the system's eigen-energies in terms of the qubit transition frequencies and the strength of the inter-qubit coupling, and describe the sensitivity of the energy crossing/anti-crossing features to such coupling. We compute the hybrid system's dissipative dynamics for the cases of i) collective and ii) independent decoherence, whereby the system interacts with one common and two different baths of harmonic oscillators, respectively. The calculations have been performed within the Bloch-Redfield formalism and we report the solutions for the populations and the coherences of the system's reduced density matrix. The dephasing and relaxation rates are explicitly calculated as a function of the heat bath temperature.
Thermodynamique des moteurs thermiques aux structures dissipatives
Prigogine, Ilya
1999-01-01
Ce livre constitue à la fois une présentation complète de la thermodynamique et une introduction scientifique à l'œuvre de Prigogine. Les auteurs innovent en montrant comment la thermodynamique du non-équilibre est un prolongement naturel de la thermodynamique de l'équilibre. Elle constitue ainsi la science des processus irréversibles - " la flèche du temps " - dont les structures dissipatives sont les témoignages les plus éclatants. Les développements historiques en font, non seulement un texte de référence, mais aussi un livre de culture. Les nombreux exemples et exercices, comme les programmes informatiques et les références aux sites Internet en font un outil de travail irremplaçable.
Quantum Markov Chain Mixing and Dissipative Engineering
DEFF Research Database (Denmark)
Kastoryano, Michael James
2012-01-01
This thesis is the fruit of investigations on the extension of ideas of Markov chain mixing to the quantum setting, and its application to problems of dissipative engineering. A Markov chain describes a statistical process where the probability of future events depends only on the state...... of the system at the present point in time, but not on the history of events. Very many important processes in nature are of this type, therefore a good understanding of their behaviour has turned out to be very fruitful for science. Markov chains always have a non-empty set of limiting distributions...... (stationary states). The aim of Markov chain mixing is to obtain (upper and/or lower) bounds on the number of steps it takes for the Markov chain to reach a stationary state. The natural quantum extensions of these notions are density matrices and quantum channels. We set out to develop a general mathematical...
International Nuclear Information System (INIS)
Saffouri, M.H.
1982-07-01
A rigorous treatment of the problem of Cerenkov radiation from fast moving electric and magnetic charges is presented. This is based on the rigorous solution of Maxwell's equations in a general dispersive medium possessing dielectric and magnetic properties and with, and without, dissipation. It is shown that the fields are completely determined by one scalar function. Expressions for the exact fields are obtained. From the asymptotic fields all the relevant properties of Cerenkov radiation are reproduced. In particular, it is shown that in the absence of dissipation the energy in each mode travels with the phase velocity of that mode. For a dissipative medium the electric field develops a longitudinal component and the energy propagates at an angle to the phase velocity. Application to the case of a Tachyon shows that it must emit Cerenkov radiation in vacuum. An estimate is given for the resulting linear density of emitted radiation. Finally, two suggestions are made for the experimental detection of magnetic charges and electric dipole moments of elementary particles based upon the Cerenkov radiation which they would emit in dispersive media. (author)
Integration of Satellite and Terrestrial Networks at JPL
Pinck, D. S.
1995-01-01
This presentation focuses on the activities at JPL on the integration of satellite and terrestrial networks for mobile and personal communications. Activities fall into two categories: 1)advanced systems work, and 2)laboratory and field experimentation. Results of a workshop held at JPL on PCS integration and interoperability will be presented. Experiments will be described.
Energy Technology Data Exchange (ETDEWEB)
Costa, V.A.F. [Departamento de Engenharia Mecanica, Universidade de Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)
2006-07-15
Care needs to be taken when considering the viscous dissipation in the energy conservation formulation of the natural convection problem in fluid-saturated porous media. The unique energy formulation compatible with the First Law of Thermodynamics informs us that if the viscous dissipation term is taken into account, also the work of pressure forces term needs to be taken into account. In integral terms, the work of pressure forces must equal the energy dissipated by viscous effects, and the net energy generation in the overall domain must be zero. If only the (positive) viscous dissipation term is considered in the energy conservation equation, the domain behaves as a heat multiplier, with an heat output greater than the heat input. Only the energy formulation consistent with the First Law of Thermodynamics leads to the correct flow and temperature fields, as well as of the heat transfer parameters characterizing the involved porous device. Attention is given to the natural convection problem in a square enclosure filled with a fluid-saturated porous medium, using the Darcy Law to describe the fluid flow, but the main ideas and conclusions apply equally for any general natural or mixed convection heat transfer problem. It is also analyzed the validity of the Oberbeck-Boussinesq approximation when applied to natural convection problems in fluid-saturated porous media. (author)
Dissipation dynamics of terbuthylazine in soil during the maize growing season.
Stipičević, Sanja; Mendaš, Gordana; Dvoršćak, Marija; Fingler, Sanja; Galzina, Natalija; Barić, Klara
2017-12-20
Ever since terbuthylazine (TBA) replaced atrazine in herbicide crop treatment, its much greater persistence has raised considerable environmental concern. The aim of our field experiment was to establish the dissipation dynamics of TBA and its degradation product desethylterbuthylazine (DET) in soil over five months of maize growth. We applied TBA as part of pre-emergent treatment in the regular and double-the-regular amounts. Soil samples were collected periodically at the following depths: 0-10 cm, 10-20 cm, 20-30 cm, and 30-50 cm. For TBA and DET soil residue analysis we used microwave-assisted extraction with methanol, followed by HPLC-UV/DAD. Regardless of the application rate, more than 80 % of the applied TBA dissipated from the first 50 cm of soil in the two months after herbicide application and 120 mm of rainfall. Three months later (at maize harvest), less than 4 % of total TBA remained in the soil, mostly in the top 20 cm rich with organic carbon on which TBA is likelier to adsorb. The loss of TBA from soil coincided with the rise in DET, especially the top soil layers, during the periods of low rainfall and highest soil temperatures. This points to biodegradation as the main route of TBA dissipation in humic soils. The applied amount had no significant effect on TBA dissipation in the top (humic) layers, but in the layers with less than 1 % of organic carbon, it was higher when the doublethe- regular dose was applied.
Quantum phase transitions of light in a dissipative Dicke-Bose-Hubbard model
Wu, Ren-Cun; Tan, Lei; Zhang, Wen-Xuan; Liu, Wu-Ming
2017-09-01
The impact that the environment has on the quantum phase transition of light in the Dicke-Bose-Hubbard model is investigated. Based on the quasibosonic approach, mean-field theory, and perturbation theory, the formulation of the Hamiltonian, the eigenenergies, and the superfluid order parameter are obtained analytically. Compared with the ideal cases, the order parameter of the system evolves with time as the photons naturally decay in their environment. When the system starts with the superfluid state, the dissipation makes the photons more likely to localize, and a greater hopping energy of photons is required to restore the long-range phase coherence of the localized state of the system. Furthermore, the Mott lobes depend crucially on the numbers of atoms and photons (which disappear) of each site, and the system tends to be classical with the number of atoms increasing; however, the atomic number is far lower than that expected under ideal circumstances. As there is an inevitable interaction between the coupled-cavity array and its surrounding environment in the actual experiments, the system is intrinsically dissipative. The results obtained here provide a more realistic image for characterizing the dissipative nature of quantum phase transitions in lossy platforms, which will offer valuable insight into quantum simulation of a dissipative system and which are helpful in guiding experimentalists in open quantum systems.
Viscous Flow over Nonlinearly Stretching Sheet with Effects of Viscous Dissipation
Directory of Open Access Journals (Sweden)
Javad Alinejad
2012-01-01
Full Text Available The flow and heat transfer characteristics of incompressible viscous flow over a nonlinearly stretching sheet with the presence of viscous dissipation is investigated numerically. The similarity transformation reduces the time-independent boundary layer equations for momentum and thermal energy into a set of coupled ordinary differential equations. The obtained equations, including nonlinear equation for the velocity field and differential equation by variable coefficient for the temperature field , are solved numerically by using the fourth order of Runge-Kutta integration scheme accompanied by shooting technique with Newton-Raphson iteration method. The effect of various values of Prandtl number, Eckert number and nonlinear stretching parameter are studied. The results presented graphically show some behaviors such as decrease in dimensionless temperature due to increase in Pr number, and curve relocations are observed when heat dissipation is considered.
Dissipative differential systems and the state space H∞ control problem
Trentelman, H.L.; Willems, J.C.
2000-01-01
The purpose of this paper is to apply our very recent results on the synthesis of dissipative linear differential systems to the 'classical' state space H∞ control problem. We first review our general problem set-up, where the problem of rendering a given plant dissipative by general
Balance laws and centro velocity in dissipative systems
van Groesen, Embrecht W.C.; Mainardi, F.
1990-01-01
Starting with a density that is conserved for a dynamical system when dissipation is ignored, a local conservation law is derived for which the total flux (integrated over the spatial domain) is unique. When dissipation is incorporated, the conservation law becomes a balance law. The contribution
Observation of flow dissipation in 3He-B
International Nuclear Information System (INIS)
Eisenstein, J.P.; Packard, R.E.
1982-01-01
Anomalous dissipation is observed in 3 He-B flowing in a U-tube device. The dissipation is of unknown origin and persists to the lowest measured velocity. The position of this result in the framework of other 3 He-B flow experiments is discussed
Braun-Le Chatelier principle in dissipative thermodynamics
Pavelka, Michal; Grmela, Miroslav
2016-01-01
Braun-Le Chatelier principle is a fundamental result of equilibrium thermodynamics, showing how stable equilibrium states shift when external conditions are varied. The principle follows from convexity of thermodynamic potential. Analogously, from convexity of dissipation potential it follows how steady non-equilibrium states shift when thermodynamic forces are varied, which is the extension of the principle to dissipative thermodynamics.
The thermodynamic basis of entransy and entransy dissipation
International Nuclear Information System (INIS)
Xu, Mingtian
2011-01-01
In the present work, the entransy and entransy dissipation are defined from the thermodynamic point of view. It is shown that the entransy is a state variable and can be employed to describe the second law of thermodynamics. For heat conduction, a principle of minimum entransy dissipation is established based on the second law of thermodynamics in terms of entransy dissipation, which leads to the governing equation of the steady Fourier heat conduction without heat source. Furthermore, we derive the expressions of the entransy dissipation in duct flows and heat exchangers from the second law of thermodynamics, which paves the way for applications of the entransy dissipation theory in heat exchanger design. -- Highlights: → The concepts of entransy and entransy dissipation are defined from the thermodynamic point of view. → We find that the entransy is a new thermodynamic property. → The second law of thermodynamics can be described by the entransy and entransy dissipation. → The expressions of entransy dissipation in duct flows and heat exchangers are derived from the second law of thermodynamics.
Direct and indirect detection of dissipative dark matter
Energy Technology Data Exchange (ETDEWEB)
Fan, JiJi; Katz, Andrey; Shelton, Jessie, E-mail: jijifan1982@gmail.com, E-mail: katz.andrey@gmail.com, E-mail: jshelton137@gmail.com [Department of Physics, Harvard University, Cambridge, MA 02138 (United States)
2014-06-01
We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints.
Dissipative quantum trajectories in complex space: Damped harmonic oscillator
International Nuclear Information System (INIS)
Chou, Chia-Chun
2016-01-01
Dissipative quantum trajectories in complex space are investigated in the framework of the logarithmic nonlinear Schrödinger equation. The logarithmic nonlinear Schrödinger equation provides a phenomenological description for dissipative quantum systems. Substituting the wave function expressed in terms of the complex action into the complex-extended logarithmic nonlinear Schrödinger equation, we derive the complex quantum Hamilton–Jacobi equation including the dissipative potential. It is shown that dissipative quantum trajectories satisfy a quantum Newtonian equation of motion in complex space with a friction force. Exact dissipative complex quantum trajectories are analyzed for the wave and solitonlike solutions to the logarithmic nonlinear Schrödinger equation for the damped harmonic oscillator. These trajectories converge to the equilibrium position as time evolves. It is indicated that dissipative complex quantum trajectories for the wave and solitonlike solutions are identical to dissipative complex classical trajectories for the damped harmonic oscillator. This study develops a theoretical framework for dissipative quantum trajectories in complex space.
Dissipative nucleus-nucleus collisions: study of memory effects
International Nuclear Information System (INIS)
Agarwal, K.C.; Yadav, H.L.
2002-01-01
Dissipative collisions between two heavy nuclei are described in terms of a macroscopic dynamical model within the framework of a multi-dimensional Fokker-Planck equation. The reaction 86 Kr(8.18 MeV/u) + 166 Er has been used as a prototype to study and demonstrate the memory effects for dissipation and diffusion processes
Dissipative quantum trajectories in complex space: Damped harmonic oscillator
Energy Technology Data Exchange (ETDEWEB)
Chou, Chia-Chun, E-mail: ccchou@mx.nthu.edu.tw
2016-10-15
Dissipative quantum trajectories in complex space are investigated in the framework of the logarithmic nonlinear Schrödinger equation. The logarithmic nonlinear Schrödinger equation provides a phenomenological description for dissipative quantum systems. Substituting the wave function expressed in terms of the complex action into the complex-extended logarithmic nonlinear Schrödinger equation, we derive the complex quantum Hamilton–Jacobi equation including the dissipative potential. It is shown that dissipative quantum trajectories satisfy a quantum Newtonian equation of motion in complex space with a friction force. Exact dissipative complex quantum trajectories are analyzed for the wave and solitonlike solutions to the logarithmic nonlinear Schrödinger equation for the damped harmonic oscillator. These trajectories converge to the equilibrium position as time evolves. It is indicated that dissipative complex quantum trajectories for the wave and solitonlike solutions are identical to dissipative complex classical trajectories for the damped harmonic oscillator. This study develops a theoretical framework for dissipative quantum trajectories in complex space.
Two-dimensional dissipation in third sound resonance
International Nuclear Information System (INIS)
Buck, A.L.; Mochel, J.M.; Illinois Univ., Urbana
1981-01-01
The first determination of non-linear superflow dissipation in a truly two-dimensional helium film is reported. Superfluid velocities were measured using third sound resonance on a closed superfluid film. The predicted power law dissipation function, with exponent of approximately eight, is observed at three temperatures in a film of 0.58 mobile superfluid layers. (orig.)
estimation of ionospheric energy dissipation for the year 2012 using
African Journals Online (AJOL)
userpc
energy dissipation is the dominant channel of energy transfer in that year from the solar wind. This is consistent with many results found by other researchers. Keywords: Østgaard's Empirical Relation, Ionospheric Energy Dissipation, Electron. Precipitation, Joule Heating. INTRODUCTION. In the Earth's magnetosphere, the ...
Direct and indirect detection of dissipative dark matter
International Nuclear Information System (INIS)
Fan, JiJi; Katz, Andrey; Shelton, Jessie
2014-01-01
We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints
Influence of viscous dissipation and radiation on MHD Couette flow ...
African Journals Online (AJOL)
The overall analysis of the study of these parameters in various degrees show an increase in the velocity profile of the fluid, while radiation parameter decreases the temperature profile; viscous dissipation and Reynolds number increase the temperature profile of the fluid. Key word: Couette flow, viscous dissipation, ...
Effect of magnetic shear on dissipative drift instabilities
International Nuclear Information System (INIS)
Guzdar, P.N.; Chen, L.; Kaw, P.K.; Oberman, C.
1978-03-01
In this letter we report the results of a linear radial eigenmode analysis of dissipative drift waves in a plasma with magnetic shear and spatially varying density gradient. The results of the analysis are shown to be consistent with a recent experiment on the study of dissipative drift instabilities in a toroidal stellarator
Energy dissipation of slot-type flip buckets
Wu, Jian-hua; Li, Shu-fang; Ma, Fei
2018-03-01
The energy dissipation is a key index in the evaluation of energy dissipation elements. In the present work, a flip bucket with a slot, called the slot-type flip bucket, is theoretically and experimentally investigated by the method of estimating the energy dissipation. The theoretical analysis shows that, in order to have the energy dissipation, it is necessary to determine the sequent flow depth h 1 and the flow speed V 1 at the corresponding position through the flow depth h 2 after the hydraulic jump. The relative flow depth h 2 / h 。 is a function of the approach flow Froude number Fr 。, the relative slot width b/B 。, and the relative slot angle θ/β. The expression for estimating the energy dissipation is developed, and the maximum error is not larger than 9.21%.
Dissipation of Alfven waves in compressible inhomogeneous media
International Nuclear Information System (INIS)
Malara, F.; Primavera, L.; Veltri, P.
1997-01-01
In weakly dissipative media governed by the magnetohydrodynamics (MHD) equations, any efficient mechanism of energy dissipation requires the formation of small scales. Using numerical simulations, we study the properties of Alfven waves propagating in a compressible inhomogeneous medium, with an inhomogeneity transverse to the direction of wave propagation. Two dynamical effects, energy pinching and phase mixing, are responsible for the small-scales formation, similarly to the incompressible case. Moreover, compressive perturbations, slow waves and a static entropy wave are generated; the former are subject to steepening and form shock waves, which efficiently dissipate their energy, regardless of the Reynolds number. Rough estimates show that the dissipation times are consistent with those required to dissipate Alfven waves of photospheric origin inside the solar corona
Flux motion and dissipation in high-temperature superconductors
International Nuclear Information System (INIS)
Gray, K.E.; Kim, D.H.
1991-01-01
The effects on flux motion and dissipation of interlayer coupling of the Cu-O planes along the c-axis are considered for the high-temperature superconductors (HTS). It is argued that for the highly-anisotropic HTS, the weak interlayer coupling plays a dominant role that can be described by incoherent Josephson tunneling between superconducting Cu-O bi- or tri-layers. In YBa 2 Cu 3 O 7 , the layers are strongly coupled, presumably because the conducting Cu-O chains short circuit the Josephson tunneling, so that these effects are weak or missing. Recently, the effects of anisotropy and fluctuations on critical current densities, J c (T,H) and the field-induced broadening of resistivity transitions, ρ(T,H), have been studied in high-temperature superconductors (HTS). Although the broadening looks similar for the applied field, H, oriented either parallel to the superconducting Cu-O layers (H parallel ab) or parallel to the c-axis (H parallel c), its width and the detailed shape of ρ(T,H) are different. The explanations given in this paper for the highly anisotropic HTS differ in detail for the two cases, but have a crucial feature in common: they result from fluctuations affecting the Josephson coupling across the interlayer junctions
Fundamental mode rf power dissipated in a waveguide attached to an accelerating cavity
International Nuclear Information System (INIS)
Kang, Y.W.
1993-01-01
An accelerating RF cavity usually requires accessory devices such as a tuner, a coupler, and a damper to perform properly. Since a device is attached to the wall of the cavity to have certain electrical coupling of the cavity field through the opening. RF power dissipation is involved. In a high power accelerating cavity, the RF power coupled and dissipated in the opening and in the device must be estimated to design a proper cooling system for the device. The single cell cavities of the APS storage ring will use the same accessories. These cavities are rotationally symmetric and the fields around the equator can be approximated with the fields of the cylindrical pillbox cavity. In the following, the coupled and dissipated fundamental mode RF power in a waveguide attached to a pillbox cavity is discussed. The waveguide configurations are (1) aperture-coupled cylindrical waveguide with matched load termination; (2) short-circuited cylindrical waveguide; and (3) E-probe or H-loop coupled coaxial waveguide. A short-circuited, one-wavelength coaxial structure is considered for the fundamental frequency rejection circuit of an H-loop damper
The Planetary Terrestrial Analogues Library (PTAL)
Werner, S. C.; Dypvik, H.; Poulet, F.; Rull Perez, F.; Bibring, J.-P.; Bultel, B.; Casanova Roque, C.; Carter, J.; Cousin, A.; Guzman, A.; Hamm, V.; Hellevang, H.; Lantz, C.; Lopez-Reyes, G.; Manrique, J. A.; Maurice, S.; Medina Garcia, J.; Navarro, R.; Negro, J. I.; Neumann, E. R.; Pilorget, C.; Riu, L.; Sætre, C.; Sansano Caramazana, A.; Sanz Arranz, A.; Sobron Grañón, F.; Veneranda, M.; Viennet, J.-C.; PTAL Team
2018-04-01
The Planetary Terrestrial Analogues Library project aims to build and exploit a spectral data base for the characterisation of the mineralogical and geological evolution of terrestrial planets and small solar system bodies.
Busting dust: from cosmic grains to terrestrial microbes
International Nuclear Information System (INIS)
Mendis, D.A.
2001-01-01
Electrostatic charging can have important consequences for both the growth and disruption of microparticulates immersed in a plasma. In this topical review, my emphasis is on the latter process, while I extend the term microparticulates not only to include ordinary inanimate cosmic or terrestrial dust but also to include terrestrial microbes whose sizes range from tens of nanometers (viruses) to tens of micrometers (bacteria). Following a description of the basic mechanism of electrostatic disruption of a solid body, I will discuss the role of size, shape and surface irregularity on the process. I will also consider the mitigating role of electric field emission of electrons on the disruption process of a negatively charged grain as its size falls below a critical size. I will conclude by reviewing some early evidence for the electrostatic disruption of cosmic grains, and the very recent evidence for the electrostatic disruption of the bacterial cell membranes in terrestrial sterilization experiments. (orig.)
Terrestrial Steering Group. 2014. Arctic Terrestrial Biodiversity Monitoring Plan
DEFF Research Database (Denmark)
Aastrup, Peter; Aronsson, Mora; Barry, Tom
capacity and information may be currently available and (b) to outline near-term required steps to begin implementing the plan and reporting on an initial set of Arctic terrestrial biodiversity focal ecosystem component attributes. The specific objectives of the workshop were to: Identify key products...... for TSG for the next two years. Identify key components of a pan-Arctic status report for priority focal ecosystem components (FEC) attributes for policy and decision makers. Develop a prioritized set of activities to meet reporting objectives. Identify key milestones and timelines for the successful...... implementation of the Arctic Terrestrial Biodiversity Monitoring Plan for the next two years. Identify expert networks required for successful implementation of the plan. Identify key gaps and opportunities for the TSG related to plan implementation and identify near-term next steps to address gaps....
Spatial variability of atrazine dissipation in an allophanic soil.
Müller, Karin; Smith, Roger E; James, Trevor K; Holland, Patrick T; Rahman, Anis
2003-08-01
The small-scale variability (0.5 m) of atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) concentrations and soil water contents in a volcanic silt loam soil (Haplic Andosol, FAO system) was studied in an area of 0.1 ha. Descriptive and spatial statistics were used to analyse the data. On average we recovered 102% of the applied atrazine 2 h after the herbicide application (CV = 35%). An increase in the CV of the concentrations with depth could be ascribed to a combination of extrinsic and intrinsic factors. Both variables, atrazine concentrations and soil water content, showed a high horizontal variability. The semivariograms of the atrazine concentrations exhibited the pure nugget effect, no pattern could be determined along the 15.5-m long transects on any of the seven sampling days over a 55-day period. Soil water content had a weak spatial autocorrelation with a range of 6-10 m. The dissipation of atrazine analysed using a high vertical sampling resolution of 0.02 m to 0.2 m showed that 70% of the applied atrazine persisted in the upper 0.02-m layer of the soil for 12 days. After 55 days and 410 mm of rainfall the centre of the pesticide mass was still at a soil depth of 0.021 m. The special characteristics of the soil (high organic carbon content, allophanic clay) had a strong influence on atrazine sorption and mobility. The mass recovery after 55 days was low. The laboratory degradation rate for atrazine, determined in a complementary incubation study and corrected for the actual field temperature using the Arrhenius equation, only accounted for about 35% of the losses that occurred in the field. Results suggest field degradation rates to be more changeable in time and much faster than under controlled conditions. Preferential flow is discussed as a component of the field transport process.
Quantal and dissipative aspects in nuclear structure and dynamics
International Nuclear Information System (INIS)
Lacroix, Denis
1999-01-01
This work is devoted to the description of both quantal and statistical aspects in a coherent theoretical framework that goes beyond a mean-field approximation. It is shown that among the possible methods, the Extended mean-field theory (ETDHF) is able to describe relaxation by including correlation effects. This theory is first applied to cold and hot giant resonances. After having developed a extended version of the linear response theory the effect of collisions on the response of 40 Ca is studied. It is shown that collisions contribute to the spreading width of giant resonances and become a dominant decay channel at high temperature. The generalization of these methods through the modelization of the Hamiltonian as a series of couplings in cascade has enabled to go beyond ETDHF. Thus, phenomena as multi-scale Ericson fluctuations and interferences in the nuclear response are predicted. The study of larger amplitudes requires the introduction of transport theories for the nuclear dynamics. Thus the deexcitation of hot and compressed nuclei has been studied with mean-field theories. This analysis has clarified the link between the equation of state and the dynamical expansion in finite Systems. A comparison with semi-classical has further shown the importance of quantum effects and has demonstrated the necessity to take into account nucleon collisions in a quantum framework. The possibility to apply ETDHF to nuclear dynamics in the general case is then discussed. A rapid and reliable method, tested on a schematic model is proposed to solve the extended mean-field. The application of ETDHF to the monopolar expansion of 16 O has finally demonstrated the interesting perspectives of this theory for describing dissipative aspects in quantum dynamics. Finally, the introduction of quantum stochastic approaches is discussed. (author) [fr
ENERGY DISSIPATION AND LANDAU DAMPING IN TWO- AND THREE-DIMENSIONAL PLASMA TURBULENCE
Energy Technology Data Exchange (ETDEWEB)
Li, Tak Chu; Howes, Gregory G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Klein, Kristopher G. [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); TenBarge, Jason M. [IREAP, University of Maryland, College Park, MD 20742 (United States)
2016-12-01
Plasma turbulence is ubiquitous in space and astrophysical plasmas, playing an important role in plasma energization, but the physical mechanisms leading to dissipation of the turbulent energy remain to be definitively identified. Kinetic simulations in two dimensions (2D) have been extensively used to study the dissipation process. How the limitation to 2D affects energy dissipation remains unclear. This work provides a model of comparison between two- and three-dimensional (3D) plasma turbulence using gyrokinetic simulations; it also explores the dynamics of distribution functions during the dissipation process. It is found that both 2D and 3D nonlinear gyrokinetic simulations of a low-beta plasma generate electron velocity-space structures with the same characteristics as that of the linear Landau damping of Alfvén waves in a 3D linear simulation. The continual occurrence of the velocity-space structures throughout the turbulence simulations suggests that the action of Landau damping may be responsible for the turbulent energy transfer to electrons in both 2D and 3D, and makes possible the subsequent irreversible heating of the plasma through collisional smoothing of the velocity-space fluctuations. Although, in the 2D case where variation along the equilibrium magnetic field is absent, it may be expected that Landau damping is not possible, a common trigonometric factor appears in the 2D resonant denominator, leaving the resonance condition unchanged from the 3D case. The evolution of the 2D and 3D cases is qualitatively similar. However, quantitatively, the nonlinear energy cascade and subsequent dissipation is significantly slower in the 2D case.
Terrestrial Analogs to Mars: NRC Community Panel Decadal Report
Farr, T. G.
2002-12-01
A report was completed recently by a Community Panel for the NRC Decadal Study of Solar System Exploration. The desire was for a review of the current state of knowledge and for recommendations for action over the next decade. The topic of this panel, Terrestrial Analogs to Mars, was chosen to bring attention to the need for an increase in analog studies in support of the increased pace of Mars exploration. It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of martian meteorites), and computer and laboratory modeling. The combination of all of these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the overarching science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel considered the issues of data collection and archiving, value of field workshops, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities. Parts of this work were performed under contract to NASA.
Soap film vibration: origin of the dissipation.
Acharige, Sébastien Kosgodagan; Elias, Florence; Derec, Caroline
2014-11-07
We investigate the complex dispersion relationship of a transverse antisymmetric wave on a horizontal soap film. Experimentally, the complex wave number k at a fixed forcing frequency is determined by measuring the vibrating amplitude of the soap film: the wavelength (linked to the real part of k) is determined by the spatial variation of the amplitude; the decay length (linked to the imaginary part of k) is determined by analyzing the resonance curves of the vibrating wave as a function of frequency. Theoretically, we compute the complex dispersion relationship taking into account the physical properties of the bulk liquid and gas phase, and of the gas-liquid interfaces. The comparison between the computation (developed to the leading order under our experimental conditions) and the experimental results confirms that the phase velocity is fixed by the interplay between surface tension, and liquid and air inertia, as reported in previous studies. Moreover, we show that the attenuation of the transverse antisymmetric wave originates from the viscous dissipation in the gas phase surrounding the liquid film. This result is an important step in understanding the propagation of an acoustic wave in liquid foam, using a bottom-up approach.
Light energy dissipation under water stress conditions
International Nuclear Information System (INIS)
Stuhlfauth, T.; Scheuermann, R.; Fock, H.P.
1990-01-01
Using 14 CO 2 gas exchange and metabolite analyses, stomatal as well as total internal CO 2 uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to -2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO 2 exchange was drastically reduced, whereas the total CO 2 uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO 2 . This CO 2 -recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO 2 recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations
Light energy dissipation under water stress conditions
Energy Technology Data Exchange (ETDEWEB)
Stuhlfauth, T.; Scheuermann, R.; Fock, H.P. (Universitaet Kaiserslautern (West Germany))
1990-04-01
Using {sup 14}CO{sub 2} gas exchange and metabolite analyses, stomatal as well as total internal CO{sub 2} uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to {minus}2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO{sub 2} exchange was drastically reduced, whereas the total CO{sub 2} uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO{sub 2}. This CO{sub 2}-recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO{sub 2} recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations.
Dissipative dynamics of superconducting hybrid qubit systems
Energy Technology Data Exchange (ETDEWEB)
Montes, Enrique; Calero, Jesus M; Reina, John H, E-mail: enriquem@univalle.edu.c, E-mail: j.reina-estupinan@physics.ox.ac.u [Departamento de Fisica, Universidad del Valle, A.A. 25360, Cali (Colombia)
2009-05-01
We perform a theoretical study of composed superconducting qubit systems for the case of a coupled qubit configuration based on a hybrid qubit circuit made of both charge and phase qubits, which are coupled via a sigma{sub x} x sigma{sub z} interaction. We compute the system's eigen-energies in terms of the qubit transition frequencies and the strength of the inter-qubit coupling, and describe the sensitivity of the energy crossing/anti-crossing features to such coupling. We compute the hybrid system's dissipative dynamics for the cases of i) collective and ii) independent decoherence, whereby the system interacts with one common and two different baths of harmonic oscillators, respectively. The calculations have been performed within the Bloch-Redfield formalism and we report the solutions for the populations and the coherences of the system's reduced density matrix. The dephasing and relaxation rates are explicitly calculated as a function of the heat bath temperature.
Chakravarthy, Sunada; Gonthier, Keith A.
2016-07-01
Variations in the microstructure of granular explosives (i.e., particle packing density, size, shape, and composition) can affect their shock sensitivity by altering thermomechanical fields at the particle-scale during pore collapse within shocks. If the deformation rate is fast, hot-spots can form, ignite, and interact, resulting in burn at the macro-scale. In this study, a two-dimensional finite and discrete element technique is used to simulate and examine shock-induced dissipation and hot-spot formation within low density explosives (68%-84% theoretical maximum density (TMD)) consisting of large ensembles of HMX (C4H8N8O8) and aluminum (Al) particles (size ˜ 60 -360 μm). Emphasis is placed on identifying how the inclusion of Al influences effective shock dissipation and hot-spot fields relative to equivalent ensembles of neat/pure HMX for shocks that are sufficiently strong to eliminate porosity. Spatially distributed hot-spot fields are characterized by their number density and area fraction enabling their dynamics to be described in terms of nucleation, growth, and agglomeration-dominated phases with increasing shock strength. For fixed shock particle speed, predictions indicate that decreasing packing density enhances shock dissipation and hot-spot formation, and that the inclusion of Al increases dissipation relative to neat HMX by pressure enhanced compaction resulting in fewer but larger HMX hot-spots. Ensembles having bimodal particle sizes are shown to significantly affect hot-spot dynamics by altering the spatial distribution of hot-spots behind shocks.
Architected squirt-flow materials for energy dissipation
Cohen, Tal; Kurzeja, Patrick; Bertoldi, Katia
2017-12-01
In the present study we explore material architectures that lead to enhanced dissipation properties by taking advantage of squirt-flow - a local flow mechanism triggered by heterogeneities at the pore level. While squirt-flow is a known dominant source of dissipation and seismic attenuation in fluid saturated geological materials, we study its untapped potential to be incorporated in highly deformable elastic materials with embedded fluid-filled cavities for future engineering applications. An analytical investigation, that isolates the squirt-flow mechanism from other potential dissipation mechanisms and considers an idealized setting, predicts high theoretical levels of dissipation achievable by squirt-flow and establishes a set of guidelines for optimal dissipation design. Particular architectures are then investigated via numerical simulations showing that a careful design of the internal voids can lead to an increase of dissipation levels by an order of magnitude, compared with equivalent homogeneous void distributions. Therefore, we suggest squirt-flow as a promising mechanism to be incorporated in future architected materials to effectively and reversibly dissipate energy.
Tidal dissipation in the subsurface ocean of Enceladus
Matsuyama, I.; Hay, H.; Nimmo, F.; Kamata, S.
2017-12-01
Icy satellites of the outer solar system have emerged as potential habitable worlds due to the presence of subsurface oceans. As a long-term energy source, tidal heating in these oceans can influence the survivability of subsurface oceans, and the thermal, rotational, and orbital evolution of these satellites. Additionally, the spatial and temporal variation of tidal heating has implications for the interior structure and spacecraft observations. Previous models for dissipation in thin oceans are not generally applicable to icy satellites because either they ignore the presence of an overlying solid shell or use a thin shell membrane approximation. We present a new theoretical treatment for tidal dissipation in thin oceans with overlying shells of arbitrary thickness and apply it to Enceladus. The shell's resistance to ocean tides increases with shell thickness, reducing tidal dissipation as expected. Both the magnitude of energy dissipation and the resonant ocean thicknesses decrease as the overlying shell thickness increases, as previously shown using a membrane approximation. In contrast to previous work based on the traditional definition of the tidal quality factor, Q, our new definition is consistent with higher energy dissipation for smaller Q, and introduces a lower limit on Q. The dissipated power and tides are not in phase with the forcing tidal potential due to the delayed ocean response. The phase lag depends on the Rayleigh friction coefficient and ocean and shell thicknesses, which implies that phase lag observations can be used to constrain these parameters. Eccentricity heating produces higher dissipation near the poles, while obliquity heating produces higher dissipation near the equator, in contrast to the dissipation patterns in the shell. The time-averaged surface distribution of tidal heating can generate lateral shell thickness variations, providing an additional constraint on the Rayleigh friction coefficient. Explaining the endogenic power
Identification of energy dissipation mechanisms in CNT-reinforced nanocomposites
International Nuclear Information System (INIS)
Gardea, Frank; Lagoudas, Dimitris C; Naraghi, Mohammad; Glaz, Bryan; Riddick, Jaret
2016-01-01
In this paper we present our recent findings on the mechanisms of energy dissipation in polymer-based nanocomposites obtained through experimental investigations. The matrix of the nanocomposite was polystyrene (PS) which was reinforced with carbon nanotubes (CNTs). To study the mechanical strain energy dissipation of nanocomposites, we measured the ratio of loss to storage modulus for different CNT concentrations and alignments. CNT alignment was achieved via hot-drawing of PS-CNT. In addition, CNT agglomeration was studied via a combination of SEM imaging and Raman scanning. We found that at sufficiently low strains, energy dissipation in composites with high CNT alignment is not a function of applied strain, as no interfacial slip occurs between the CNTs and PS. However, below the interfacial slip strain threshold, damping scales monotonically with CNT content, which indicates the prevalence of CNT-CNT friction dissipation mechanisms within agglomerates. At higher strains, interfacial slip also contributes to energy dissipation. However, the increase in damping with strain, especially when CNT agglomerates are present, does not scale linearly with the effective interface area between CNTs and PS, suggesting a significant contribution of friction between CNTs within agglomerates to energy dissipation at large strains. In addition, for the first time, a comparison between the energy dissipation in randomly oriented and aligned CNT composites was made. It is inferred that matrix plasticity and tearing caused by misorientation of CNTs with the loading direction is a major cause of energy dissipation. The results of our research can be used to design composites with high energy dissipation capability, especially for applications where dynamic loading may compromise structural stability and functionality, such as rotary wing structures and antennas. (paper)
Spatial vision in Bombus terrestris
Directory of Open Access Journals (Sweden)
Aravin eChakravarthi
2016-02-01
Full Text Available Bombus terrestris is one of the most commonly used insect models to investigate visually guided behavior and spatial vision in particular. Two fundamental measures of spatial vision are spatial resolution and contrast sensitivity. In this study, we report the threshold of spatial resolution in B. terrestris and characterize the contrast sensitivity function of the bumblebee visual system for a dual choice discrimination task. We trained bumblebees in a Y-maze experimental set-up to associate a vertical sinusoidal grating with a sucrose reward, and a horizontal grating with absence of a reward. Using a logistic psychometric function, we estimated a resolution threshold of 0.21 cycles deg-1 of visual angle. This resolution is in the same range but slightly lower than that found in honeybees (Apis mellifera and A. cerana and another bumblebee species (B. impatiens. We also found that the contrast sensitivity of B. terrestris was 1.57 for the spatial frequency 0.09 cycles deg-1 and 1.26. for 0.18 cycles deg-1.
Global dissipativity of continuous-time recurrent neural networks with time delay
International Nuclear Information System (INIS)
Liao Xiaoxin; Wang Jun
2003-01-01
This paper addresses the global dissipativity of a general class of continuous-time recurrent neural networks. First, the concepts of global dissipation and global exponential dissipation are defined and elaborated. Next, the sets of global dissipativity and global exponentially dissipativity are characterized using the parameters of recurrent neural network models. In particular, it is shown that the Hopfield network and cellular neural networks with or without time delays are dissipative systems
Energy dissipation through wind-generated breaking waves
Institute of Scientific and Technical Information of China (English)
ZHANG Shuwen; CAO Ruixue; XIE Lingling
2012-01-01
Wave breaking is an important process that controls turbulence properties and fluxes of heat and mass in the upper oceanic layer.A model is described for energy dissipation per unit area at the ocean surface attributed to wind-generated breaking waves,in terms of ratio of energy dissipation to energy input,windgenerated wave spectrum,and wave growth rate.Also advanced is a vertical distribution model of turbulent kinetic energy,based on an exponential distribution method.The result shows that energy dissipation rate depends heavily on wind speed and sea state.Our results agree well with predictions of previous works.
Relative Entropy, Interaction Energy and the Nature of Dissipation
Directory of Open Access Journals (Sweden)
Bernard Gaveau
2014-06-01
Full Text Available Many thermodynamic relations involve inequalities, with equality if a process does not involve dissipation. In this article we provide equalities in which the dissipative contribution is shown to involve the relative entropy (a.k.a. Kullback-Leibler divergence. The processes considered are general time evolutions both in classical and quantum mechanics, and the initial state is sometimes thermal, sometimes partially so. By calculating a transport coefficient we show that indeed—at least in this case—the source of dissipation in that coefficient is the relative entropy.
Skyrmionic spin Seebeck effect via dissipative thermomagnonic torques
Kovalev, Alexey A.
2014-06-01
We derive thermomagnonic torque and its "β-type" dissipative correction from the stochastic Landau-Lifshitz-Gilbert equation. The β-type dissipative correction describes viscous coupling between magnetic dynamics and magnonic current and it stems from spin mistracking of the magnetic order. We show that thermomagnonic torque is important for describing temperature gradient induced motion of skyrmions in helical magnets while dissipative correction plays an essential role in generating transverse Magnus force. We propose to detect such skyrmionic motion by employing the transverse spin Seebeck effect geometry.
Influence of queue propagation and dissipation on route travel times
DEFF Research Database (Denmark)
Raovic, Nevena
into account (Bliemer, 2008). Yperman (2007) indicates that there is a significant difference in queue-propagation and queue-dissipation between the LTM and DQM. This results in different route travel times, and can further affect route choice. In this paper, different approaches to represent queue propagation...... and dissipation through the CTM, LTM and DQM are studied. A simple network allows to show how these approaches influence route travel time. Furthermore, the possibility of changing the existing DQM is considered in order to more realistically represent queue propagation and dissipation, which would lead to more...... accurate route travel times....
Engineering high-order nonlinear dissipation for quantum superconducting circuits
Mundhada, S. O.; Grimm, A.; Touzard, S.; Shankar, S.; Minev, Z. K.; Vool, U.; Mirrahimi, M.; Devoret, M. H.
Engineering nonlinear driven-dissipative processes is essential for quantum control. In the case of a harmonic oscillator, nonlinear dissipation can stabilize a decoherence-free manifold, leading to protected quantum information encoding. One possible approach to implement such nonlinear interactions is to combine the nonlinearities provided by Josephson circuits with parametric pump drives. However, it is usually hard to achieve strong nonlinearities while avoiding undesired couplings. Here we propose a scheme to engineer a four-photon drive and dissipation in a harmonic oscillator by cascading experimentally demonstrated two-photon processes. We also report experimental progress towards realization of such a scheme. Work supported by: ARO, ONR, AFOSR and YINQE.
Solar terrestrial coupling through space plasma processes
International Nuclear Information System (INIS)
Birn, J.
2000-01-01
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project investigates plasma processes that govern the interaction between the solar wind, charged particles ejected from the sun, and the earth's magnetosphere, the region above the ionosphere governed by the terrestrial magnetic field. Primary regions of interest are the regions where different plasma populations interact with each other. These are regions of particularly dynamic plasma behavior, associated with magnetic flux and energy transfer and dynamic energy release. The investigations concerned charged particle transport and energization, and microscopic and macroscopic instabilities in the magnetosphere and adjacent regions. The approaches combined space data analysis with theory and computer simulations
Radio techniques for probing the terrestrial ionosphere.
Hunsucker, R. D.
The subject of the book is a description of the basic principles of operation, plus the capabilities and limitations of all generic radio techniques employed to investigate the terrestrial ionosphere. The purpose of this book is to present to the reader a balanced treatment of each technique so they can understand how to interpret ionospheric data and decide which techniques are most effective for studying specific phenomena. The first two chapters outline the basic theory underlying the techniques, and each following chapter discusses a separate technique. This monograph is entirely devoted to techniques in aeronomy and space physics. The approach is unique in its presentation of the principles, capabilities and limitations of the most important presently used radio techniques. Typical examples of data are shown for the various techniques, and a brief historical account of the technique development is presented. An extended annotated bibliography of the salient papers in the field is included.
Accelerated stress testing of terrestrial solar cells
Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.
1982-01-01
The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.
Contaminant-State Broadening Mechanism in a Driven Dissipative Rydberg System
Porto, J. V.
2017-04-01
The strong interactions in Rydberg atoms make them an ideal system for the study of correlated many-body physics, both in the presence and absence of dissipation. Using such highly excited atomic states requires addressing challenges posed by the dense spectrum of Rydberg levels, the detrimental effects of spontaneous emission, and strong interactions. A full understanding of the scope and limitations of many Rydberg-based proposals requires simultaneously including these effects, which typically cannot be described by a mean-field treatment due to correlations in the quantum coherent and dissipative processes. We study a driven, dissipative system of Rydberg atoms in a 3D optical lattice, and observe substantial deviation from single-particle excitation rates, both on and off resonance. The observed broadened spectra cannot be explained by van der Waals interactions or a mean-field treatment of the system. Based on the magnitude of the broadening and the scaling with density and two-photon Rabi frequency, we attribute these effects to unavoidable blackbody-induced transitions to nearby Rydberg states of opposite parity, which have large, resonant dipole-dipole interactions with the state of interest. Even at low densities of Rydberg atoms, uncontrolled production of atoms in other states significantly modifies the energy levels of the remaining atoms. These off-diagonal exchange interactions result in complex many-body states of the system and have implications for off-resonant Rydberg dressing proposals. This work was partially supported by the ARL-CDQI program.
International Nuclear Information System (INIS)
Kondoh, Yoshiomi; Hakoiwa, Toru; Okada, Akihito; Kobayashi, Naohiro; Takahashi, Toshiki
2006-01-01
A novel set of simultaneous eigenvalue equations having dissipative terms are derived to find self-similarly evolving and minimally dissipated stable states of plasmas realized after relaxation and self-organization processes. By numerically solving the set of eigenvalue equations in a cylindrical model, typical spatial profiles of plasma parameters, electric and magnetic fields and diffusion factors are presented, all of which determine self-consistently with each other by physical laws and mutual relations among them, just as in experimental plasmas. (author)
Static and dynamic properties of smoothed dissipative particle dynamics
Alizadehrad, Davod; Fedosov, Dmitry A.
2018-03-01
In this paper, static and dynamic properties of the smoothed dissipative particle dynamics (SDPD) method are investigated. We study the effect of method parameters on SDPD fluid properties, such as structure, speed of sound, and transport coefficients, and show that a proper choice of parameters leads to a well-behaved and accurate fluid model. In particular, the speed of sound, the radial distribution function (RDF), shear-thinning of viscosity, the mean-squared displacement (〈R2 〉 ∝ t), and the Schmidt number (Sc ∼ O (103) - O (104)) can be controlled, such that the model exhibits a fluid-like behavior for a wide range of temperatures in simulations. Furthermore, in addition to the consideration of fluid density variations for fluid compressibility, a more challenging test of incompressibility is performed by considering the Poisson ratio and divergence of velocity field in an elongational flow. Finally, as an example of complex-fluid flow, we present the applicability and validity of the SDPD method with an appropriate choice of parameters for the simulation of cellular blood flow in irregular geometries. In conclusion, the results demonstrate that the SDPD method is able to approximate well a nearly incompressible fluid behavior, which includes hydrodynamic interactions and consistent thermal fluctuations, thereby providing, a powerful approach for simulations of complex mesoscopic systems.
Kinetic analysis of thermally relativistic flow with dissipation
International Nuclear Information System (INIS)
Yano, Ryosuke; Suzuki, Kojiro
2011-01-01
Nonequilibrium flow of thermally relativistic matter with dissipation is considered in the framework of the relativistic kinetic theory. As an object of the analysis, the supersonic rarefied flow of thermally relativistic matter around the triangle prism is analyzed using the Anderson-Witting model. Obtained numerical results indicate that the flow field changes in accordance with the flow velocity and temperature of the uniform flow owing to both effects derived from the Lorentz contraction and thermally relativistic effects, even when the Mach number of the uniform flow is fixed. The profiles of the heat flux along the stagnation streamline can be approximated on the basis of the relativistic Navier-Stokes-Fourier (NSF) law except for a strong nonequilibrium regime such as the middle of the shock wave and the vicinity of the wall, whereas the profile of the heat flux behind the triangle prism cannot be approximated on the basis of the relativistic NSF law owing to rarefied effects via the expansion behind the triangle prism. Additionally, the heat flux via the gradient of the static pressure is non-negligible owing to thermally relativistic effects. The profile of the dynamic pressure is different from that approximated on the basis of the NSF law, which is obtained by the Eckart decomposition. Finally, variations of convections of the mass and momentum owing to the effects derived from the Lorentz contraction and thermally relativistic effects are numerically confirmed.
From Lattice Boltzmann to hydrodynamics in dissipative relativistic fluids
Gabbana, Alessandro; Mendoza, Miller; Succi, Sauro; Tripiccione, Raffaele
2017-11-01
Relativistic fluid dynamics is currently applied to several fields of modern physics, covering many physical scales, from astrophysics, to atomic scales (e.g. in the study of effective 2D systems such as graphene) and further down to subnuclear scales (e.g. quark-gluon plasmas). This talk focuses on recent progress in the largely debated connection between kinetic transport coefficients and macroscopic hydrodynamic parameters in dissipative relativistic fluid dynamics. We use a new relativistic Lattice Boltzmann method (RLBM), able to handle from ultra-relativistic to almost non-relativistic flows, and obtain strong evidence that the Chapman-Enskog expansion provides the correct pathway from kinetic theory to hydrodynamics. This analysis confirms recently obtained theoretical results, which can be used to obtain accurate calibrations for RLBM methods applied to realistic physics systems in the relativistic regime. Using this calibration methodology, RLBM methods are able to deliver improved physical accuracy in the simulation of the physical systems described above. European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 642069.
Effects of dust on the propagation and dissipation of Alfven waves in interstellar clouds
International Nuclear Information System (INIS)
Pilipp, W.; Morfill, G.E.; Hartquist, T.W.; Havnes, O.; Maryland Univ., College Park; Nordlysobservatoriet, Tromso, Norway)
1987-01-01
The propagation of circularly polarized Alfven waves in dusty, weakly ionized media consisting of three gaseous fluids and of one size of grains that are either neutral or singly ionized is numerically investigated. For a molecular hydrogen number density of 10,000/cu cm, a magnetic field strength of 0.0001 G, and a temperature of 20 K, the waves are well coupled when the wavelengths exceed about 1 pc. The grains can reduce the minimum wavelength for coupled waves to about 0.1 pc and the dissipation rates of well-coupled small-amplitude waves by an order of magnitude. The speeds and dissipation rates of decoupled Alfven waves with frequencies well above 0.01/yr and wavelengths well below 0.01 pc are altered greatly over a wide range of frequencies by the presence of grains. In particular, right-handed circularly polarized waves are affected strongly by gyroresonance and cutoff effects. 18 references
Dissipative inertial transport patterns near coherent Lagrangian eddies in the ocean.
Beron-Vera, Francisco J; Olascoaga, María J; Haller, George; Farazmand, Mohammad; Triñanes, Joaquín; Wang, Yan
2015-08-01
Recent developments in dynamical systems theory have revealed long-lived and coherent Lagrangian (i.e., material) eddies in incompressible, satellite-derived surface ocean velocity fields. Paradoxically, observed drifting buoys and floating matter tend to create dissipative-looking patterns near oceanic eddies, which appear to be inconsistent with the conservative fluid particle patterns created by coherent Lagrangian eddies. Here, we show that inclusion of inertial effects (i.e., those produced by the buoyancy and size finiteness of an object) in a rotating two-dimensional incompressible flow context resolves this paradox. Specifically, we obtain that anticyclonic coherent Lagrangian eddies attract (repel) negatively (positively) buoyant finite-size particles, while cyclonic coherent Lagrangian eddies attract (repel) positively (negatively) buoyant finite-size particles. We show how these results explain dissipative-looking satellite-tracked surface drifter and subsurface float trajectories, as well as satellite-derived Sargassum distributions.
International Nuclear Information System (INIS)
Hossain, M.A.; Arbad, O.
1988-07-01
Effect of buoyancy force in a laminar uniform forced convection flow past a semi-infinite vertical plate has been analyzed near the leading edge, taking into account the viscous dissipation. The coupled non-linear locally similar equations, which govern the flow, are solved by the method of parametric differentiation. Effects of the buoyancy force and the heat due to viscous dissipation on the flow and the temperature fields as well as on the wall shear-stress and the heat transfer at the surface of the plate are shown graphically for the values of the Prandtl number σ ranging from 10 -1 to 1.0. (author). 20 refs, 3 figs, 2 tabs
Scattering of traveling spots in dissipative systems
Nishiura, Yasumasa; Teramoto, Takashi; Ueda, Kei-Ichi
2005-12-01
One of the fundamental questions for self-organization in pattern formation is how spatial periodic structure is spontaneously formed starting from a localized fluctuation. It is known in dissipative systems that splitting dynamics is one of the driving forces to create many particle-like patterns from a single seed. On the way to final state there occur many collisions among them and its scattering manner is crucial to predict whether periodic structure is realized or not. We focus on the colliding dynamics of traveling spots arising in a three-component system and study how the transition of scattering dynamics is brought about. It has been clarified that hidden unstable patterns called "scattors" and their stable and unstable manifolds direct the traffic flow of orbits before and after collisions. The collision process in general can be decomposed into several steps and each step is controlled by such a scattor, in other words, a network among scattors forms the backbone for scattering dynamics. A variety of input-output relations comes from the complexity of the network as well as high Morse indices of the scattor. The change of transition manners is caused by the switching of the network from one structure to another, and such a change is caused by the singularities of scattors. We illustrate a typical example of the change of transition caused by the destabilization of the scattor. A new instability of the scattor brings a new destination for the orbit resulting in a new input-output relation, for instance, Hopf instability for the scattor of peanut type brings an annihilation.
A dissipative model of solar system
Vladimir, V. G.
2009-04-01
rotation of planets, and the small tidal deformations arising under influence of gradients of gravitational forces. The method of division of movements receives the equations describing movements of the centers of weights of planets and their own rotations. In the offered model takes place a dissipation of the energy which source are internally viscous forces of each planet. The system supposes the first integral - the law of preservation of the kinetic moment concerning the centre of weights of system. As a result of deformations of planets in the law of the universal gravitation which has been written down for material points, there are small conservative amendments. The equations of movement describe movement of the centers of weights of planets and their rotation around of the centers of weights in view of the tidal phenomena and the dissipative forces. The connected system of the equations consists of 3N the vector equations of the second order representing the theorems of movement of the centers of weights of planets, and N the vector equations of the first order determining changes of the own kinetic moments of each planet. Stationary values of full mechanical energy on the variety set in integral of the kinetic moment, correspond to stationary movements - to rotations of system as firm body with constant angular speed around of the centre of weights of all system. Angular speed of stationary rotation is directed along a constant vector of the kinetic moment, and the axis of rotation is the main central axis of inertia of system. We shall notice, that deformations of planets in stationary movement are constant, as in system of coordinates rotating with constant angular speed centrifugal forces and forces of gravitational interaction of planets are constant. Stationary configurations of system are determined according to Routh`s technique as stationary points of the changed potential energy submitted by the sum potential energies of centrifugal and gravitational
Kim, Min-Kwan; Sim, Jaegun; Lee, Jae-Hyeok; Kim, Miyoung; Kim, Sang-Koog
2018-05-01
We explore robust magnetization-dynamic behaviors in soft magnetic nanoparticles in single-domain states and find their related high-efficiency energy-dissipation mechanism using finite-element micromagnetic simulations. We also make analytical derivations that provide deeper physical insights into the magnetization dynamics associated with Gilbert damping parameters under applications of time-varying rotating magnetic fields of different strengths and frequencies and static magnetic fields. Furthermore, we find that the mass-specific energy-dissipation rate at resonance in the steady-state regime changes remarkably with the strength of rotating fields and static fields for given damping constants. The associated magnetization dynamics are well interpreted with the help of the numerical calculation of analytically derived explicit forms. The high-efficiency energy-loss power can be obtained using soft magnetic nanoparticles in the single-domain state by tuning the frequency of rotating fields to the resonance frequency; what is more, it is controllable via the rotating and static field strengths for a given intrinsic damping constant. We provide a better and more efficient means of achieving specific loss power that can be implemented in magnetic hyperthermia applications.
Non-Markovian dissipative quantum mechanics with stochastic trajectories
International Nuclear Information System (INIS)
Koch, Werner
2010-01-01
All fields of physics - be it nuclear, atomic and molecular, solid state, or optical - offer examples of systems which are strongly influenced by the environment of the actual system under investigation. The scope of what is called ''the environment'' may vary, i.e., how far from the system of interest an interaction between the two does persist. Typically, however, it is much larger than the open system itself. Hence, a fully quantum mechanical treatment of the combined system without approximations and without limitations of the type of system is currently out of reach. With the single assumption of the environment to consist of an internally thermalized set of infinitely many harmonic oscillators, the seminal work of Stockburger and Grabert [Chem. Phys., 268:249-256, 2001] introduced an open system description that captures the environmental influence by means of a stochastic driving of the reduced system. The resulting stochastic Liouville-von Neumann equation describes the full non-Markovian dynamics without explicit memory but instead accounts for it implicitly through the correlations of the complex-valued noise forces. The present thesis provides a first application of the Stockburger-Grabert stochastic Liouville-von Neumann equation to the computation of the dynamics of anharmonic, continuous open systems. In particular, it is demonstrated that trajectory based propagators allow for the construction of a numerically stable propagation scheme. With this approach it becomes possible to achieve the tremendous increase of the noise sample count necessary to stochastically converge the results when investigating such systems with continuous variables. After a test against available analytic results for the dissipative harmonic oscillator, the approach is subsequently applied to the analysis of two different realistic, physical systems. As a first example, the dynamics of a dissipative molecular oscillator is investigated. Long time propagation - until
Non-Markovian dissipative quantum mechanics with stochastic trajectories
Energy Technology Data Exchange (ETDEWEB)
Koch, Werner
2010-09-09
All fields of physics - be it nuclear, atomic and molecular, solid state, or optical - offer examples of systems which are strongly influenced by the environment of the actual system under investigation. The scope of what is called ''the environment'' may vary, i.e., how far from the system of interest an interaction between the two does persist. Typically, however, it is much larger than the open system itself. Hence, a fully quantum mechanical treatment of the combined system without approximations and without limitations of the type of system is currently out of reach. With the single assumption of the environment to consist of an internally thermalized set of infinitely many harmonic oscillators, the seminal work of Stockburger and Grabert [Chem. Phys., 268:249-256, 2001] introduced an open system description that captures the environmental influence by means of a stochastic driving of the reduced system. The resulting stochastic Liouville-von Neumann equation describes the full non-Markovian dynamics without explicit memory but instead accounts for it implicitly through the correlations of the complex-valued noise forces. The present thesis provides a first application of the Stockburger-Grabert stochastic Liouville-von Neumann equation to the computation of the dynamics of anharmonic, continuous open systems. In particular, it is demonstrated that trajectory based propagators allow for the construction of a numerically stable propagation scheme. With this approach it becomes possible to achieve the tremendous increase of the noise sample count necessary to stochastically converge the results when investigating such systems with continuous variables. After a test against available analytic results for the dissipative harmonic oscillator, the approach is subsequently applied to the analysis of two different realistic, physical systems. As a first example, the dynamics of a dissipative molecular oscillator is investigated. Long time
Sharan, Nek; Matheou, Georgios; Dimotakis, Paul
2017-11-01
Artificial numerical dissipation decreases dispersive oscillations and can play a key role in mitigating unphysical scalar excursions in large eddy simulations (LES). Its influence on scalar mixing can be assessed through the resolved-scale scalar, Z , its probability density function (PDF), variance, spectra, and the budget of the horizontally averaged equation for Z2. LES of incompressible temporally evolving shear flow enabled us to study the influence of numerical dissipation on unphysical scalar excursions and mixing estimates. Flows with different mixing behavior, with both marching and non-marching scalar PDFs, are studied. Scalar fields for each flow are compared for different grid resolutions and numerical scalar-convection term schemes. As expected, increasing numerical dissipation enhances scalar mixing in the development stage of shear flow characterized by organized large-scale pairings with a non-marching PDF, but has little influence in the self-similar stage of flows with marching PDFs. Flow parameters and regimes sensitive to numerical dissipation help identify approaches to mitigate unphysical excursions while minimizing dissipation.
Thermo-electric transport in gauge/gravity models with momentum dissipation
Amoretti, Andrea; Braggio, Alessandro; Maggiore, Nicola; Magnoli, Nicodemo; Musso, Daniele
2014-09-01
We present a systematic definition and analysis of the thermo-electric linear response in gauge/gravity systems focusing especially on models with massive gravity in the bulk and therefore momentum dissipation in the dual field theory. A precise treatment of finite counter-terms proves to be essential to yield a consistent physical picture whose hydrodynamic and beyond-hydrodynamics behaviors noticeably match with field theoretical expectations. The model furnishes a possible gauge/gravity description of the crossover from the quantum-critical to the disorder-dominated Fermi-liquid behaviors, as expected in graphene.
On the influence of dissipative effects on instabilities of differentially-rotating plasmas
International Nuclear Information System (INIS)
Lakhin, V. P.; Ilgisonis, V. I.
2010-01-01
The stability of differentially-rotating cylindrical plasmas in the axial homogeneous magnetic field is studied in the framework of one-fluid dissipative magnetohydrodynamics. The dispersion relation of small-scale axisymmetric perturbations, taking into account the effects of the plasma thermal stratification, its resistivity and its viscosity, is derived. In the limiting cases of negligible resistivity and of negligible viscosity, the criteria of plasma stability are obtained. It is shown that in the case of small viscosity, the azimuthal flow of resistive plasma in the axial magnetic field is unstable due to the buoyancy effect if both the plasma pressure and its entropy either increase or decrease in the radial direction.
Transformation procedures in 3D terrestrial coordinate systems
Directory of Open Access Journals (Sweden)
Sedlák Vladimír
2001-12-01
Full Text Available Transformation procedures belong to the main tasks of surveyor working in a field of geodesy, for example in satellite geodesy or astronomical geodesy. It is necessary to know transformation procedures in 3D terrestrial (Earth coordinate systems. Increasingly a dynamic advance growth of application of satellite navigation systems, for example GPS (Global Positioning System into engineering surveying, real estate register and others spheres of applied geodesy and geo-surveying (mine surveying exacts knowledge of these transformation procedures between coordinates in various coordinate systems. These tasks are common for daily work for various practical surveyors too, not only for theoretical scientific working surveyors.Conventional Terrestrial System is 3D coordinate system what is the most important coordinate system in global geodesy. Conventional Terrestrial System is an approximation of the nature coordinate system of the Earth. The origin of this coordinate system is placed in the earth substantial centre of gravity and in the centre of geoid. Conventional Terrestrial System is the Cartesian right-handed coordinate system, i.e. positive one. The Local Astronomical System is 3D coordinate system too and it belongs to an important coordinate system in geodesy from its practical point of view. Many geodetic measurements are realized in this coordinate system. Designation of this coordinate system as astronomical system expresses its sticking to a normal line to an equipotential plane, i.e. to a vertical. Local Astronomical system is the left-handed cartesian coordinate system.Transformation procedures in 3D terrestrial coordinate systems with theory of these systems are presented in the paper. Transformation in the local astronomical coordinate system presents common transformation in a frame of an adjustment of various local geodetic networks. In a case of satellite measurements (GPS, satellite altimetry, etc. transformation between local and
Linking terrestrial and marine conservation planning and threats analysis.
Tallis, Heather; Ferdaña, Zach; Gray, Elizabeth
2008-02-01
The existence of the Gulf of Mexico dead zone makes it clear that marine ecosystems can be damaged by terrestrial inputs. Marine and terrestrial conservation planning need to be aligned in an explicit fashion to fully represent threats to marine systems. To integrate conservation planning for terrestrial and marine systems, we used a novel threats assessment that included 5 cross-system threats in a site-prioritization exercise for the Pacific Northwest coast ecoregion (U.S.A.). Cross-system threats are actions or features in one ecological realm that have effects on species in another realm. We considered bulkheads and other forms of shoreline hardening threats to terrestrial systems and roads, logging, agriculture, and urban areas threats to marine systems. We used 2 proxies of freshwater influence on marine environments, validated against a mechanistic model and field observations, to propagate land-based threats into marine sites. We evaluated the influence of cross-system threats on conservation priorities by comparing MARXAN outputs for 3 scenarios that identified terrestrial and marine priorities simultaneously: (1) no threats, (2) single-system threats, and (3) single- and cross-system threats. Including cross-system threats changed the threat landscape dramatically. As a result the best plan that included only single-system threats identified 323 sites (161,500 ha) at risk from cross-system threats. Including these threats changed the location of best sites. By comparing the best and sum solutions of the single- and cross-system scenarios, we identified areas ideal for preservation or restoration through integrated management. Our findings lend quantitative support to the call for explicitly integrated decision making and management action in terrestrial and marine ecosystems.
The effects of dissipation on topological mechanical systems
Xiong, Ye; Wang, Tianxiang; Tong, Peiqing
2016-09-01
We theoretically study the effects of isotropic dissipation in a topological mechanical system which is an analogue of Chern insulator in mechanical vibrational lattice. The global gauge invariance is still conserved in this system albeit it is destroyed by the dissipation in the quantum counterpart. The chiral edge states in this system are therefore robust against strong dissipation. The dissipation also causes a dispersion of damping for the eigenstates. It will modify the equation of motion of a wave packet by an extra effective force. After taking into account the Berry curvature in the wave vector space, the trace of a free wave packet in the real space should be curved, feinting to break the Newton’s first law.
Energy-dissipation-model for metallurgical multi-phase-systems
Energy Technology Data Exchange (ETDEWEB)
Mavrommatis, K.T. [Rheinisch-Westfaelische Technische Hochschule Aachen, Aachen (Germany)
1996-12-31
Entropy production in real processes is directly associated with the dissipation of energy. Both are potential measures for the proceed of irreversible processes taking place in metallurgical systems. Many of these processes in multi-phase-systems could then be modelled on the basis of the energy-dissipation associated with. As this entity can often be estimated using very simple assumptions from first principles, the evolution of an overall measure of systems behaviour can be studied constructing an energy-dissipation -based model of the system. In this work a formulation of this concept, the Energy-Dissipation-Model (EDM), for metallurgical multi-phase-systems is given. Special examples are studied to illustrate the concept, and benefits as well as the range of validity are shown. This concept might be understood as complement to usual CFD-modelling of complex systems on a more abstract level but reproducing essential attributes of complex metallurgical systems. (author)
Nonoscillatory shock capturing scheme using flux limited dissipation
International Nuclear Information System (INIS)
Jameson, A.
1985-01-01
A method for modifying the third order dissipative terms by the introduction of flux limiters is proposed. The first order dissipative terms can then be eliminated entirely, and in the case of a scalar conservation law the scheme is converted into a total variation diminishing scheme provided that an appropriate value is chosen for the dissipative coefficient. Particular attention is given to: (1) the treatment of the scalar conservation law; (2) the treatment of the Euler equations for inviscid compressible flow; (3) the boundary conditions; and (4) multistage time stepping and multigrid schemes. Numerical results for transonic flows suggest that a central difference scheme augmented by flux limited dissipative terms can lead to an effective nonoscillatory shock capturing method. 20 references
On the quantization of sectorially Hamiltonian dissipative systems
Energy Technology Data Exchange (ETDEWEB)
Castagnino, M. [Instituto de Fisica de Rosario, 2000 Rosario (Argentina); Instituto de Astronomia y Fisica del Espacio, Casilla de Correos 67, Sucursal 28, 1428 Buenos Aires (Argentina); Gadella, M. [Instituto de Fisica de Rosario, 2000 Rosario (Argentina); Departamento de Fisica Teorica, Atomica y Optica, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid (Spain)], E-mail: manuelgadella@yahoo.com.ar; Lara, L.P. [Instituto de Fisica de Rosario, 2000 Rosario (Argentina); Facultad Regional Rosario, UTN, 2000 Rosario (Argentina)
2009-10-15
We present a theoretical discussion showing that, although some dissipative systems may have a sectorial Hamiltonian description, this description does not allow for canonical quantization. However, a quantum Liouville counterpart of these systems is possible, although it is not unique.
On the quantization of sectorially Hamiltonian dissipative systems
International Nuclear Information System (INIS)
Castagnino, M.; Gadella, M.; Lara, L.P.
2009-01-01
We present a theoretical discussion showing that, although some dissipative systems may have a sectorial Hamiltonian description, this description does not allow for canonical quantization. However, a quantum Liouville counterpart of these systems is possible, although it is not unique.
Energy-dissipation-model for metallurgical multi-phase-systems
Energy Technology Data Exchange (ETDEWEB)
Mavrommatis, K T [Rheinisch-Westfaelische Technische Hochschule Aachen, Aachen (Germany)
1997-12-31
Entropy production in real processes is directly associated with the dissipation of energy. Both are potential measures for the proceed of irreversible processes taking place in metallurgical systems. Many of these processes in multi-phase-systems could then be modelled on the basis of the energy-dissipation associated with. As this entity can often be estimated using very simple assumptions from first principles, the evolution of an overall measure of systems behaviour can be studied constructing an energy-dissipation -based model of the system. In this work a formulation of this concept, the Energy-Dissipation-Model (EDM), for metallurgical multi-phase-systems is given. Special examples are studied to illustrate the concept, and benefits as well as the range of validity are shown. This concept might be understood as complement to usual CFD-modelling of complex systems on a more abstract level but reproducing essential attributes of complex metallurgical systems. (author)
Dissipation in a Quantum Wire: Fact and Fantasy
International Nuclear Information System (INIS)
Das, Mukunda P.; Green, Frederick
2008-01-01
Where, and how, does energy dissipation of electrical energy take place in a ballistic wire? Fully two decades after the advent of the transmissive phenomenology of electrical conductance, this deceptively simple query remains unanswered. We revisit the quantum kinetic basis of dissipation and show its power to give a definitive answer to our query. Dissipation leaves a clear, quantitative trace in the non-equilibrium current noise of a quantum point contact; this signature has already been observed in the laboratory. We then highlight the current state of accepted understandings in the light of well-known yet seemingly contradictory measurements. The physics of mesoscopic transport rests not in coherent carrier transmission through a perfect and dissipationless metallic channel, but explicitly in their dissipative inelastic scattering at the wire's interfaces and adjacent macroscopic leads.
Quantum dynamics in nanoscale magnets in dissipative environments
Miyashita, S; Saito, K; Kobayashi, H.; de Raedt, H.A.
2000-01-01
In discrete energy structure of nanoscale magnets, nonadiabatic transitions at avoided level crossings lead to fundamental processes of dynamics of magnetizations. The thermal environment causes dissipative effects on these processes. In this paper we review the features of the nonadiabatic
Dissipative Structures of the Kuramoto–Sivashinsky Equation
Directory of Open Access Journals (Sweden)
N. A. Kudryashov
2015-01-01
Full Text Available In the present work, we study the features of dissipative structures formation described by the periodic boundary value problem for the Kuramoto-Sivashinsky equation. The numerical algorithm which is based on the pseudospectral method is presented. We prove the efficiency and accuracy of the proposed numerical method on the exact solution of the equation considered. Using this approach, we performed the numerical simulation of dissipative structure formations described by the Kuramoto–Sivashinsky equation. The influence of the problem parameters on these processes are studied. The quantitative and qualitative characteristics of dissipative structure formations are described. We have shown that there is a value of the control parameter at which the processes of dissipative structure formation are observed. In particular, using the cyclic convolution we define the average value of this parameter. Also, we find the dependence of the amplitude of the structures on the value of control parameter.
Reversible dissipative processes, conformal motions and Landau damping
International Nuclear Information System (INIS)
Herrera, L.; Di Prisco, A.; Ibáñez, J.
2012-01-01
The existence of a dissipative flux vector is known to be compatible with reversible processes, provided a timelike conformal Killing vector (CKV) χ α =(V α )/T (where V α and T denote the four-velocity and temperature respectively) is admitted by the spacetime. Here we show that if a constitutive transport equation, either within the context of standard irreversible thermodynamics or the causal Israel–Stewart theory, is adopted, then such a compatibility also requires vanishing dissipative fluxes. Therefore, in this later case the vanishing of entropy production generated by the existence of such CKV is not actually associated to an imperfect fluid, but to a non-dissipative one. We discuss also about Landau damping. -- Highlights: ► We review the problem of compatibility of dissipation with reversibility. ► We show that the additional assumption of a transport equation renders such a compatibility trivial. ► We discuss about Landau damping.
Beam-to-Column Connections with Demountable Energy Dissipative Plates
Directory of Open Access Journals (Sweden)
Vasile-Mircea Venghiac
2018-03-01
Full Text Available The behavior of steel structures subjected to seismic actions depends directly on the connections behavior. There are two current tendencies for ensuring the structural ductility: allowing the formation of plastic hinges in the beams by using reduced beam sections or reduced web sections or by ensuring the plastic hinge formation in the connection by using dissipative elements. This paper presents a new perspective regarding the energy dissipation mechanism formation within the beam-to-column connection. The design of connections capable of dissipating large amounts of energy, with an acceptable strength and ductile behavior is a real challenge for engineers. Sustainability is a big advantage for these connections. Another big advantage is the possibility of restoring the functionality of the damaged construction in a short time interval and with reduced costs. The introduction of connections with demountable energy dissipative plates can be a step forward in designing new beam-to-column connections for steel structures.
Effect of viscous dissipation and radiation in an annular cone
International Nuclear Information System (INIS)
Ahmed, N. J. Salman; Kamangar, Sarfaraz; Khan, T. M. Yunus; Azeem
2016-01-01
The viscous dissipation is an effect due to which heat is generated inside the medium. The presence of radiation further complicates the heat transfer behavior inside porous medium. The present paper discusses the combined effect of viscous dissipation and radiation inside a porous medium confined in an annular cone with inner radius r_i. The viscous dissipation and radiation terms are included in the energy equation thereby solving the coupled momentum and energy equations with the help of finite element method. The results are presented in terms of isothermal and streamline indicating the thermal and fluid flow behavior of porous medium. It is found that the combination of viscous dissipation and radiation parameter and the cone angle has significant effect on the heat transfer and fluid flow behavior inside the porous medium. The fluid velocity is found to increase with the increase in Raleigh number
Effect of viscous dissipation and radiation in an annular cone
Energy Technology Data Exchange (ETDEWEB)
Ahmed, N. J. Salman; Kamangar, Sarfaraz [Centre for Energy Sciences, Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 Malaysia (Malaysia); Khan, T. M. Yunus, E-mail: yunus.tatagar@gmail.com [Centre for Energy Sciences, Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 Malaysia (Malaysia); Dept. of Mechanical Engineering, BVB College of Engineering & Technology, Hubli (India); Azeem [Dept. of Computer System & Technology, University of Malaya, Kuala Lumpur (Malaysia)
2016-06-21
The viscous dissipation is an effect due to which heat is generated inside the medium. The presence of radiation further complicates the heat transfer behavior inside porous medium. The present paper discusses the combined effect of viscous dissipation and radiation inside a porous medium confined in an annular cone with inner radius r{sub i}. The viscous dissipation and radiation terms are included in the energy equation thereby solving the coupled momentum and energy equations with the help of finite element method. The results are presented in terms of isothermal and streamline indicating the thermal and fluid flow behavior of porous medium. It is found that the combination of viscous dissipation and radiation parameter and the cone angle has significant effect on the heat transfer and fluid flow behavior inside the porous medium. The fluid velocity is found to increase with the increase in Raleigh number.
Dissipative phenomena in deep inelastic heavy ion collisions
International Nuclear Information System (INIS)
Gross, D.H.E.; Krappe, H.J.; Lindenberger, K.H.; Lipperheide, R.; Moehring, K.
1978-01-01
During this meeting the following theoretical concepts for deep-inelastic heavy ion reactions were discussed: the energy transfer and friction, direct or statistical mechanisms, dissipation and fluctuation. (WL) [de
Dissipative light-bullets in the filamentation of femtosecond pulses
International Nuclear Information System (INIS)
Porras, M.A.; Gonzalo, I.
2010-01-01
Complete text of publication follows. With the growing interest in filamentation in solid and liquid media, the regime of filamentation with anomalous dispersion is receiving more attention. In this work we show that basics aspects of the filament dynamics in this regime can be explained in terms of a novel type of light-bullet, which is not of solitary or of conical types, but a wave-packet that maximizes the energy dissipation into the medium while remaining localized and stationary in propagation. We first show that a nonlinear optical medium at a given carrier wave length at which dispersion is anomalous, supports 'dissipative' light-bullets, i.e., waves localized in space and time and that propagate without change as a result of a balance between nonlinear compression and nonlinear absorption. Among them, the particular dissipative light-bullet with the highest possible dissipation is unique in a given medium, in the sense that all its properties are fixed by the properties of the medium at the carrier wave length. In this light-bullet, self-focusing continuously transports energy towards the pulse center by an amount that just compensates for the nonlinear losses. Figure 1(a) shows the radial profiles of the dissipative light-bullets that maximizes energy dissipation for several orders of multi-photon absorption responsible for the nonlinear losses. We have also found that this dissipative light-bullet tends to be spontaneously formed in the filamentary dynamics in media with anomalous dispersion. Figure 1(b) shows the peak intensity, the total energy and losses of a pulse that undergoes self-focusing and filamentation in an ideal medium with only Kerr nonlinearity and multi-photon absorption. This simple model reproduces the particularly long filament 'segments' and the 'burst' observed in experiments and in more accurate simulations. The peak intensity in the filament is identical to that of the dissipative light-bullet with maximum dissipation, and the
Transitions in the Communication Capacity of Dissipative Qubit Channels
Daems, D.
2009-05-01
The information transmission is studied for quantum channels in which the noise includes dissipative effects, more specifically, nonunitality. Noise is usually a nuisance but can sometimes be helpful. For these channels, the communication capacity is shown to increase with the dissipative component of the noise and may exhibit transitions beyond which it increases faster. The optimal states are constructed analytically as well as the pertaining “phase” diagram.
Transport theory of dissipative heavy-ion collisions
International Nuclear Information System (INIS)
Norenberg, W.
1979-01-01
The lectures present the formulation of a transport theory, the derivation of a practicable transport equation (Fokker-Planck equation) and the evaluation of transport coefficients for dissipative (or deeply inelastic) heavy-ion collisions. The applicability of the theoretical concept is tested with remarkable success in the analyses of various experimental information (mass transfer, angular-momentum dissipation and energy loss). Some critical remarks on the present situation of transport theories are added. Future developments are outlined. (author)
Research on Characteristics of New Energy Dissipation With Symmetrical Structure
Ming, Wen; Huang, Chun-mei; Huang, Hao-wen; Wang, Xin-fang
2018-03-01
Utilizing good energy consumption capacity of arc steel bar, a new energy dissipation with symmetrical structure was proposed in this article. On the base of collection experimental data of damper specimen Under low cyclic reversed loading, finite element models were built by using ANSYS software, and influences of parameter change (Conduction rod diameter, Actuation plate thickness, Diameter of arc steel rod, Curved bars initial bending) on energy dissipation performance were analyzed. Some useful conclusions which can lay foundations for practical application were drawn.
New results from dissipative diabatic dynamics and nuclear elastoplasticity
International Nuclear Information System (INIS)
Noerenberg, W.; Technische Hochschule Darmstadt
1986-10-01
I present new results about dissipative diabatic dynamics and nuclear elastoplasticity, in particular on a self-consistent diabatic formulation, on first numerical calculations of dissipative diabatic dynamics in two collective degrees of freedom, on quasi-elastic recoil in central nucleus-nucleus collisions, on the diabatic hindrance of fusion reactions and on the diabatic emission of nucleons in central nucleus-nucleus collisions. (orig./HSI)
Transport theory of dissipative heavy-ion collisions
International Nuclear Information System (INIS)
Noerenberg, W.
1979-03-01
The lectures present the formulation of a transport theory, the derivation of a practicable transport equation (Fokker-Planck equation) and the evaluation of transport coefficients for dissipative (or deeply inelastic) heavyion collisions. The applicability of the theoretical concept is tested with remarkable success in the analyses of various experimental informations (mass transfer, angular-momentum dissipation and energy loss). Some critical remarks on the present situation of transport theories are added. Future developments are outlined. (orig.) [de
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
Dissipation and spontaneous symmetry breaking in brain dynamics
International Nuclear Information System (INIS)
Freeman, Walter J; Vitiello, Giuseppe
2008-01-01
We compare the predictions of the dissipative quantum model of the brain with neurophysiological data collected from electroencephalograms resulting from high-density arrays fixed on the surfaces of primary sensory and limbic areas of trained rabbits and cats. Functional brain imaging in relation to behavior reveals the formation of coherent domains of synchronized neuronal oscillatory activity and phase transitions predicted by the dissipative model
The TKE dissipation rate in the northern South China Sea
Lozovatsky, Iossif; Liu, Zhiyu; Fernando, Harindra Joseph S.; Hu, Jianyu; Wei, Hao
2013-12-01
The microstructure measurements taken during the summer seasons of 2009 and 2010 in the northern South China Sea (between 18°N and 22.5°N, and from the Luzon Strait to the eastern shelf of China) were used to estimate the averaged dissipation rate in the upper pycnocline of the deep basin and on the shelf. Linear correlation between and the estimates of available potential energy of internal waves, which was found for this data set, indicates an impact of energetic internal waves on spatial structure and temporal variability of . On the shelf stations, the bottom boundary layer depth-integrated dissipation reaches 17-19 mW/m2, dominating the dissipation in the water column below the surface layer. In the pycnocline, the integrated dissipation was mostly ˜10-30 % of . A weak dependence of bin-averaged dissipation on the Richardson number was noted, according to , where ɛ 0 + ɛ m is the background value of for weak stratification and Ri cr = 0.25, pointing to the combined effects of shear instability of small-scale motions and the influence of larger-scale low frequency internal waves. The latter broadly agrees with the MacKinnon-Gregg scaling for internal-wave-induced turbulence dissipation.
Cold collisions in dissipative optical lattices
International Nuclear Information System (INIS)
Piilo, J; Suominen, K-A
2005-01-01
The invention of laser cooling methods for neutral atoms allows optical and magnetic trapping of cold atomic clouds in the temperature regime below 1 mK. In the past, light-assisted cold collisions between laser cooled atoms have been widely studied in magneto-optical atom traps (MOTs). We describe here theoretical studies of dynamical interactions, specifically cold collisions, between atoms trapped in near-resonant, dissipative optical lattices. The extension of collision studies to the regime of optical lattices introduces several complicating factors. For the lattice studies, one has to account for the internal substates of atoms, position-dependent matter-light coupling, and position-dependent couplings between the atoms, in addition to the spontaneous decay of electronically excited atomic states. The developed one-dimensional quantum-mechanical model combines atomic cooling and collision dynamics in a single framework. The model is based on Monte Carlo wavefunction simulations and is applied when the lattice-creating lasers have frequencies both below (red-detuned lattice) and above (blue-detuned lattice) the atomic resonance frequency. It turns out that the radiative heating mechanism affects the dynamics of atomic cloud in a red-detuned lattice in a way that is not directly expected from the MOT studies. The optical lattice and position-dependent light-matter coupling introduces selectivity of collision partners. The atoms which are most mobile and energetic are strongly favoured to participate in collisions, and are more often ejected from the lattice, than the slow ones in the laser parameter region selected for study. Consequently, the atoms remaining in the lattice have a smaller average kinetic energy per atom than in the case of non-interacting atoms. For blue-detuned lattices, we study how optical shielding emerges as a natural part of the lattice and look for ways to optimize the effect. We find that the cooling and shielding dynamics do not mix
International Nuclear Information System (INIS)
Chenel, A.; Meier, C.; Dive, G.; Desouter-Lecomte, M.
2015-01-01
We compare the strategy found by the optimal control theory in a complex molecular system according to the active subspace coupled to the field. The model is the isomerization during a Cope rearrangement of Thiele’s ester that is the most stable dimer obtained by the dimerization of methyl-cyclopentadienenylcarboxylate. The crudest partitioning consists in retaining in the active space only the reaction coordinate, coupled to a dissipative bath of harmonic oscillators which are not coupled to the field. The control then fights against dissipation by accelerating the passage across the transition region which is very wide and flat in a Cope reaction. This mechanism has been observed in our previous simulations [Chenel et al., J. Phys. Chem. A 116, 11273 (2012)]. We compare here, the response of the control field when the reaction path is coupled to a second active mode. Constraints on the integrated intensity and on the maximum amplitude of the fields are imposed limiting the control landscape. Then, optimum field from one-dimensional simulation cannot provide a very high yield. Better guess fields based on the two-dimensional model allow the control to exploit different mechanisms providing a high control yield. By coupling the reaction surface to a bath, we confirm the link between the robustness of the field against dissipation and the time spent in the delocalized states above the transition barrier
Energy Technology Data Exchange (ETDEWEB)
Griffith, Stacy R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2017-02-01
The 2017 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base has been prepared in accordance with the “Letter of Agreement Between Department of Energy, National Nuclear Security Administration, Sandia Field Office (DOE/NNSA/SFO) and 377th Air Base Wing (ABW), Kirtland Air Force Base (KAFB) for Terrestrial Sampling” (signed January 2017), Sandia National Laboratories, New Mexico (SNL/NM). The Letter of Agreement requires submittal of an annual terrestrial sampling plan.
Energy Technology Data Exchange (ETDEWEB)
Griffith, Stacy R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2018-01-01
The 2018 Annual Terrestrial Sampling Plan for Sandia National Laboratories/New Mexico on Kirtland Air Force Base has been prepared in accordance with the “Letter of Agreement Between Department of Energy, National Nuclear Security Administration, Sandia Field Office (DOE/NNSA/SFO) and 377th Air Base Wing (ABW), Kirtland Air Force Base (KAFB) for Terrestrial Sampling” (signed January 2017), Sandia National Laboratories, New Mexico (SNL/NM). The Letter of Agreement requires submittal of an annual terrestrial sampling plan.