Inference with minimal Gibbs free energy in information field theory
International Nuclear Information System (INIS)
Ensslin, Torsten A.; Weig, Cornelius
2010-01-01
Non-linear and non-Gaussian signal inference problems are difficult to tackle. Renormalization techniques permit us to construct good estimators for the posterior signal mean within information field theory (IFT), but the approximations and assumptions made are not very obvious. Here we introduce the simple concept of minimal Gibbs free energy to IFT, and show that previous renormalization results emerge naturally. They can be understood as being the Gaussian approximation to the full posterior probability, which has maximal cross information with it. We derive optimized estimators for three applications, to illustrate the usage of the framework: (i) reconstruction of a log-normal signal from Poissonian data with background counts and point spread function, as it is needed for gamma ray astronomy and for cosmography using photometric galaxy redshifts, (ii) inference of a Gaussian signal with unknown spectrum, and (iii) inference of a Poissonian log-normal signal with unknown spectrum, the combination of (i) and (ii). Finally we explain how Gaussian knowledge states constructed by the minimal Gibbs free energy principle at different temperatures can be combined into a more accurate surrogate of the non-Gaussian posterior.
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W. L. Silva
2008-09-01
Full Text Available The reduction efficiency is an important variable during the black liquor burning process in the Kraft recovery boiler. This variable value is obtained by slow experimental routines and the delay of this measure disturbs the pulp and paper industry customary control. This paper describes an optimization approach for the reduction efficiency determination in the furnace bottom of the recovery boiler based on the minimization of the Gibbs free energy. The industrial data used in this study were directly obtained from CENIBRA's data acquisition system. The resulting approach is able to predict the steady state behavior of the chemical composition of the furnace recovery boiler, - especially the reduction efficiency when different operational conditions are used. This result confirms the potential of this approach in the analysis of the daily operation of the recovery boiler.
International Nuclear Information System (INIS)
Lima da Silva, Aline; Heck, Nestor Cesar
2003-01-01
Equilibrium concentrations are traditionally calculated with the help of equilibrium constant equations from selected reactions. This procedure, however, is only useful for simpler problems. Analysis of the equilibrium state in a multicomponent and multiphase system necessarily involves solution of several simultaneous equations, and, as the number of system components grows, the required computation becomes more complex and tedious. A more direct and general method for solving the problem is the direct minimization of the Gibbs energy function. The solution for the nonlinear problem consists in minimizing the objective function (Gibbs energy of the system) subjected to the constraints of the elemental mass-balance. To solve it, usually a computer code is developed, which requires considerable testing and debugging efforts. In this work, a simple method to predict equilibrium composition in multicomponent systems is presented, which makes use of an electronic spreadsheet. The ability to carry out these calculations within a spreadsheet environment shows several advantages. First, spreadsheets are available 'universally' on nearly all personal computers. Second, the input and output capabilities of spreadsheets can be effectively used to monitor calculated results. Third, no additional systems or programs need to be learned. In this way, spreadsheets can be as suitable in computing equilibrium concentrations as well as to be used as teaching and learning aids. This work describes, therefore, the use of the Solver tool, contained in the Microsoft Excel spreadsheet package, on computing equilibrium concentrations in a multicomponent system, by the method of direct Gibbs energy minimization. The four phases Fe-Cr-O-C-Ni system is used as an example to illustrate the method proposed. The pure stoichiometric phases considered in equilibrium calculations are: Cr 2 O 3 (s) and FeO C r 2 O 3 (s). The atmosphere consists of O 2 , CO e CO 2 constituents. The liquid iron
International Nuclear Information System (INIS)
Naslain, R.; Thebault, J.; Hagenmuller, P.; Bernard, C.
1979-01-01
A thermodynamic approach based on the minimization of the total Gibbs free energy of the system is used to study the chemical vapour deposition (CVD) of boron from BCl 3 -H 2 or BBr 3 -H 2 mixtures on various types of substrates (at 1000 < T< 1900 K and 1 atm). In this approach it is assumed that states close to equilibrium are reached in the boron CVD apparatus. (Auth.)
Comment on "Inference with minimal Gibbs free energy in information field theory".
Iatsenko, D; Stefanovska, A; McClintock, P V E
2012-03-01
Enßlin and Weig [Phys. Rev. E 82, 051112 (2010)] have introduced a "minimum Gibbs free energy" (MGFE) approach for estimation of the mean signal and signal uncertainty in Bayesian inference problems: it aims to combine the maximum a posteriori (MAP) and maximum entropy (ME) principles. We point out, however, that there are some important questions to be clarified before the new approach can be considered fully justified, and therefore able to be used with confidence. In particular, after obtaining a Gaussian approximation to the posterior in terms of the MGFE at some temperature T, this approximation should always be raised to the power of T to yield a reliable estimate. In addition, we show explicitly that MGFE indeed incorporates the MAP principle, as well as the MDI (minimum discrimination information) approach, but not the well-known ME principle of Jaynes [E.T. Jaynes, Phys. Rev. 106, 620 (1957)]. We also illuminate some related issues and resolve apparent discrepancies. Finally, we investigate the performance of MGFE estimation for different values of T, and we discuss the advantages and shortcomings of the approach.
A Gibbs Energy Minimization Approach for Modeling of Chemical Reactions in a Basic Oxygen Furnace
Kruskopf, Ari; Visuri, Ville-Valtteri
2017-12-01
In modern steelmaking, the decarburization of hot metal is converted into steel primarily in converter processes, such as the basic oxygen furnace. The objective of this work was to develop a new mathematical model for top blown steel converter, which accounts for the complex reaction equilibria in the impact zone, also known as the hot spot, as well as the associated mass and heat transport. An in-house computer code of the model has been developed in Matlab. The main assumption of the model is that all reactions take place in a specified reaction zone. The mass transfer between the reaction volume, bulk slag, and metal determine the reaction rates for the species. The thermodynamic equilibrium is calculated using the partitioning of Gibbs energy (PGE) method. The activity model for the liquid metal is the unified interaction parameter model and for the liquid slag the modified quasichemical model (MQM). The MQM was validated by calculating iso-activity lines for the liquid slag components. The PGE method together with the MQM was validated by calculating liquidus lines for solid components. The results were compared with measurements from literature. The full chemical reaction model was validated by comparing the metal and slag compositions to measurements from industrial scale converter. The predictions were found to be in good agreement with the measured values. Furthermore, the accuracy of the model was found to compare favorably with the models proposed in the literature. The real-time capability of the proposed model was confirmed in test calculations.
International Nuclear Information System (INIS)
Okano, Yasushi
1999-08-01
In order to analyze the reaction heat and compounds due to sodium combustion, the multiphase chemical equilibrium calculation program for chemical reaction among sodium, oxygen and hydrogen is developed in this study. The developed numerical program is named BISHOP; which denotes Bi-Phase, Sodium - Oxygen - Hydrogen, Chemical Equilibrium Calculation Program'. Gibbs free energy minimization method is used because of the special merits that easily add and change chemical species, and generally deal many thermochemical reaction systems in addition to constant temperature and pressure one. Three new methods are developed for solving multi-phase sodium reaction system in this study. One is to construct equation system by simplifying phase, and the other is to expand the Gibbs free energy minimization method into multi-phase system, and the last is to establish the effective searching method for the minimum value. Chemical compounds by the combustion of sodium in the air are calculated using BISHOP. The Calculated temperature and moisture conditions where sodium-oxide and hydroxide are formed qualitatively agree with the experiments. Deformation of sodium hydride is calculated by the program. The estimated result of the relationship between the deformation temperature and pressure closely agree with the well known experimental equation of Roy and Rodgers. It is concluded that BISHOP can be used for evaluated the combustion and deformation behaviors of sodium and its compounds. Hydrogen formation condition of the dump-tank room at the sodium leak event of FBR is quantitatively evaluated by BISHOP. It can be concluded that to keep the temperature of dump-tank room lower is effective method to suppress the formation of hydrogen. In case of choosing the lower inflammability limit of 4.1 mol% as the hydrogen concentration criterion, formation reaction of sodium hydride from sodium and hydrogen is facilitated below the room temperature of 800 K, and concentration of hydrogen
International Nuclear Information System (INIS)
Lima da Silva, Aline; De Fraga Malfatti, Celia; Heck, Nestor Cesar
2003-01-01
The use of fuel cells is a promising technology in the conversion of chemical to electrical energy. Due to environmental concerns related to the reduction of atmospheric pollution and greenhouse gases emissions such as CO 2 , NO x and hydrocarbons, there have been many researches about fuel cells using hydrogen as fuel. Hydrogen gas can be produced by several routes; a promising one is the steam reforming of ethanol. This route may become an important industrial process, especially for sugarcane producing countries. Ethanol is renewable energy and presents several advantages over other sources related to natural availability, storage and handling safety. In order to contribute to the understanding of the steam reforming of ethanol inside the reformer, this work displays a detailed thermodynamic analysis of the ethanol/water system, in the temperature range of 500-1200K, considering different H 2 O/ethanol reforming ratios. The equilibrium determinations were done with the help of the Gibbs energy minimization method using the Generalized Reduced Gradient algorithm (GRG). Based on literature data, the species considered in calculations were: H 2 , H 2 O, CO, CO 2 , CH 4 , C 2 H 4 , CH 3 CHO, C 2 H 5 OH (gas phase) and C gr . (graphite phase). The thermodynamic conditions for carbon deposition (probably soot) on catalyst during gas reforming were analyzed, in order to establish temperature ranges and H 2 O/ethanol ratios where carbon precipitation is not thermodynamically feasible. Experimental results from literature show that carbon deposition causes catalyst deactivation during reforming. This deactivation is due to encapsulating carbon that covers active phases on a catalyst substrate, e.g. Ni over Al 2 O 3 . In the present study, a mathematical relationship between Lagrange multipliers and the carbon activity (with reference to the graphite phase) was deduced, unveiling the carbon activity in the reformer atmosphere. From this, it is possible to foreseen if soot
Directory of Open Access Journals (Sweden)
HYOUNGJU YOON
2013-02-01
Full Text Available It is required that the pH of the sump solution should be above 7.0 to retain iodine in a liquid phase and be within the material compatibility constraints under LOCA condition of PWR. The pH of the sump solution can be determined by conventional chemical equilibrium constants or by the minimization of Gibbs free energy. The latter method developed as a computer code called SOLGASMIX-PV is more convenient than the former since various chemical components can be easily treated under LOCA conditions. In this study, SOLGASMIX-PV code was modified to accommodate the acidic and basic materials produced by radiolysis reactions and to calculate the pH of the sump solution. When the computed pH was compared with measured by the ORNL experiment to verify the reliability of the modified code, the error between two values was within 0.3 pH. Finally, two cases of calculation were performed for the SKN 3&4 and UCN 1&2. As results, pH of the sump solution for the SKN 3&4 was between 7.02 and 7.45, and for the UCN 1&2 plant between 8.07 and 9.41. Furthermore, it was found that the radiolysis reactions have insignificant effects on pH because the relative concentrations of HCl, HNO3, and Cs are very low.
Enzyme Catalysis and the Gibbs Energy
Ault, Addison
2009-01-01
Gibbs-energy profiles are often introduced during the first semester of organic chemistry, but are less often presented in connection with enzyme-catalyzed reactions. In this article I show how the Gibbs-energy profile corresponds to the characteristic kinetics of a simple enzyme-catalyzed reaction. (Contains 1 figure and 1 note.)
International Nuclear Information System (INIS)
Jarungthammachote, S.; Dutta, A.
2008-01-01
Spouted beds have been found in many applications, one of which is gasification. In this paper, the gasification processes of conventional and modified spouted bed gasifiers were considered. The conventional spouted bed is a central jet spouted bed, while the modified spouted beds are circular split spouted bed and spout-fluid bed. The Gibbs free energy minimization method was used to predict the composition of the producer gas. The major six components, CO, CO 2 , CH 4 , H 2 O, H 2 and N 2 , were determined in the mixture of the producer gas. The results showed that the carbon conversion in the gasification process plays an important role in the model. A modified model was developed by considering the carbon conversion in the constraint equations and in the energy balance calculation. The results from the modified model showed improvements. The higher heating values (HHV) were also calculated and compared with the ones from experiments. The agreements of the calculated and experimental values of HHV, especially in the case of the circular split spouted bed and the spout-fluid bed were observed
Illustrating Enzyme Inhibition Using Gibbs Energy Profiles
Bearne, Stephen L.
2012-01-01
Gibbs energy profiles have great utility as teaching and learning tools because they present students with a visual representation of the energy changes that occur during enzyme catalysis. Unfortunately, most textbooks divorce discussions of traditional kinetic topics, such as enzyme inhibition, from discussions of these same topics in terms of…
First-Year University Chemistry Textbooks' Misrepresentation of Gibbs Energy
Quilez, Juan
2012-01-01
This study analyzes the misrepresentation of Gibbs energy by college chemistry textbooks. The article reports the way first-year university chemistry textbooks handle the concepts of spontaneity and equilibrium. Problems with terminology are found; confusion arises in the meaning given to [delta]G, [delta][subscript r]G, [delta]G[degrees], and…
Consistent estimation of Gibbs energy using component contributions.
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Elad Noor
Full Text Available Standard Gibbs energies of reactions are increasingly being used in metabolic modeling for applying thermodynamic constraints on reaction rates, metabolite concentrations and kinetic parameters. The increasing scope and diversity of metabolic models has led scientists to look for genome-scale solutions that can estimate the standard Gibbs energy of all the reactions in metabolism. Group contribution methods greatly increase coverage, albeit at the price of decreased precision. We present here a way to combine the estimations of group contribution with the more accurate reactant contributions by decomposing each reaction into two parts and applying one of the methods on each of them. This method gives priority to the reactant contributions over group contributions while guaranteeing that all estimations will be consistent, i.e. will not violate the first law of thermodynamics. We show that there is a significant increase in the accuracy of our estimations compared to standard group contribution. Specifically, our cross-validation results show an 80% reduction in the median absolute residual for reactions that can be derived by reactant contributions only. We provide the full framework and source code for deriving estimates of standard reaction Gibbs energy, as well as confidence intervals, and believe this will facilitate the wide use of thermodynamic data for a better understanding of metabolism.
Chemical Disequilibria and Sources of Gibbs Free Energy Inside Enceladus
Zolotov, M. Y.
2010-12-01
Earth, Mars and Europa, the moon may have no (or very limited [4]) potential for sulfate reduction. Despite nutrient (C, N, P and S) and metal (e.g. Fe, Ni) rich environments and multiple sources of Gibbs free energy during aqueous episode(s), putative life on Enceladus [4] would have adapted to survive in low water activity alkaline brines rich in ammonia, methanol and organic liquids at temperature >150-170 K. The comet-like abundances of major plume gases and apparent redox disequilibria in aquatic systems are consistent with a minimal influence of aqueous processes on endogenic chemical reactions and may indicate abiotic interior. Alternatively, plume gases may represent never melted primordial parcels of the icy shell, while the deeper interior could contain altered species transformed in abiotic and/or biological processes. Refs: [1] Waite J. et al. (2009) Nature 460, 487-490. [2] Postberg F. et al. (2009) Nature 459, 1098-1101. [3] Hansen C. et al. (2010) 38th COSPAR Sci. Assembly. [4] McKay C. et al. (2008) Astrobiology 8, 909-919.
Excess Gibbs Energy for Ternary Lattice Solutions of Nonrandom Mixing
Energy Technology Data Exchange (ETDEWEB)
Jung, Hae Young [DukSung Womens University, Seoul (Korea, Republic of)
2008-12-15
It is assumed for three components lattice solution that the number of ways of arranging particles randomly on the lattice follows a normal distribution of a linear combination of N{sub 12}, N{sub 23}, N{sub 13} which are the number of the nearest neighbor interactions between different molecules. It is shown by random number simulations that this assumption is reasonable. From this distribution, an approximate equation for the excess Gibbs energy of three components lattice solution is derived. Using this equation, several liquid-vapor equilibria are calculated and compared with the results from other equations.
Gibbs free energy of formation of UPb(s) compound
International Nuclear Information System (INIS)
Samui, Pradeep; Agarwal, Renu; Mishra, Ratikanta
2012-01-01
Liquid lead and lead-bismuth eutectic (LBE) are being explored as primary candidates for coolants in accelerator driven systems and in advanced nuclear reactors due to their favorable thermo-physical and chemical properties. They are also proposed to be used as spallation neutron source in ADS Reactor Systems. However, corrosion of structural materials (i.e. steel) presents a critical challenge for the use of liquid lead or LBE in advanced nuclear reactors. The interactions of liquid lead or LBE with clad and fuel is of great scientific and technological importance in the development of advanced nuclear reactors. Clad failure/breach can lead to reaction of coolant elements with fuel components. Thus the study of fuel-coolant interaction of U with Pb/Bi is important. The paper deals with the determination of Gibbs free energy of formation of U-rich phase i.e. UPb in Pb-U system, employing Knudsen effusion mass loss technique
Vargas, Francisco M.
2014-01-01
The temperature dependence of the Gibbs energy and important quantities such as Henry's law constants, activity coefficients, and chemical equilibrium constants is usually calculated by using the Gibbs-Helmholtz equation. Although, this is a well-known approach and traditionally covered as part of any physical chemistry course, the required…
A comparison of various Gibbs energy dissipation correlations for predicting microbial growth yields
Energy Technology Data Exchange (ETDEWEB)
Liu, J.-S. [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland); Vojinovic, V. [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland); Patino, R. [Cinvestav-Merida, Departamento de Fisica Aplicada, Km. 6 carretera antigua a Progreso, AP 73 Cordemex, 97310 Merida, Yucatan (Mexico); Maskow, Th. [UFZ Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, D-04318 Leipzig (Germany); Stockar, U. von [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland)]. E-mail: urs.vonStockar@epfl.ch
2007-06-25
Thermodynamic analysis may be applied in order to predict microbial growth yields roughly, based on an empirical correlation of the Gibbs energy of the overall growth reaction or Gibbs energy dissipation. Due to the well-known trade-off between high biomass yield and high Gibbs energy dissipation necessary for fast growth, an optimal range of Gibbs energy dissipation exists and it can be correlated to physical characteristics of the growth substrates. A database previously available in the literature has been extended significantly in order to test such correlations. An analysis of the relationship between biomass yield and Gibbs energy dissipation reveals that one does not need a very precise estimation of the latter to predict the former roughly. Approximating the Gibbs energy dissipation with a constant universal value of -500 kJ C-mol{sup -1} of dry biomass grown predicts many experimental growth yields nearly as well as a carefully designed, complex correlation available from the literature, even though a number of predictions are grossly out of range. A new correlation for Gibbs energy dissipation is proposed which is just as accurate as the complex literature correlation despite its dramatically simpler structure.
A comparison of various Gibbs energy dissipation correlations for predicting microbial growth yields
International Nuclear Information System (INIS)
Liu, J.-S.; Vojinovic, V.; Patino, R.; Maskow, Th.; Stockar, U. von
2007-01-01
Thermodynamic analysis may be applied in order to predict microbial growth yields roughly, based on an empirical correlation of the Gibbs energy of the overall growth reaction or Gibbs energy dissipation. Due to the well-known trade-off between high biomass yield and high Gibbs energy dissipation necessary for fast growth, an optimal range of Gibbs energy dissipation exists and it can be correlated to physical characteristics of the growth substrates. A database previously available in the literature has been extended significantly in order to test such correlations. An analysis of the relationship between biomass yield and Gibbs energy dissipation reveals that one does not need a very precise estimation of the latter to predict the former roughly. Approximating the Gibbs energy dissipation with a constant universal value of -500 kJ C-mol -1 of dry biomass grown predicts many experimental growth yields nearly as well as a carefully designed, complex correlation available from the literature, even though a number of predictions are grossly out of range. A new correlation for Gibbs energy dissipation is proposed which is just as accurate as the complex literature correlation despite its dramatically simpler structure
Oxidation potentials, Gibbs energies, enthalpies and entropies of actinide ions in aqueous solutions
International Nuclear Information System (INIS)
1977-01-01
The values of the Gibbs energy, enthalpy, and entropy of different actinide ions, thermodynamic characteristics of the processes of hydration of these ions, and the presently known ionization potentials of actinides are given. The enthalpy and entropy components of the oxidation potentials of actinide elements are considered. The curves of the dependence of the Gibbs energy of ion formation on the atomic number of the element and the Frost diagrams are analyzed. The diagram proposed by Frost represents the graphical dependence of the Gibbs energy of hydrated ions on the degree of oxidation of the element. Using the Frost diagram it is easy to establish whether a given ion is stable to disproportioning
Determination of Gibbs energies of formation in aqueous solution using chemical engineering tools.
Toure, Oumar; Dussap, Claude-Gilles
2016-08-01
Standard Gibbs energies of formation are of primary importance in the field of biothermodynamics. In the absence of any directly measured values, thermodynamic calculations are required to determine the missing data. For several biochemical species, this study shows that the knowledge of the standard Gibbs energy of formation of the pure compounds (in the gaseous, solid or liquid states) enables to determine the corresponding standard Gibbs energies of formation in aqueous solutions. To do so, using chemical engineering tools (thermodynamic tables and a model enabling to predict activity coefficients, solvation Gibbs energies and pKa data), it becomes possible to determine the partial chemical potential of neutral and charged components in real metabolic conditions, even in concentrated mixtures. Copyright © 2016 Elsevier Ltd. All rights reserved.
Tuck, Adrian F
2017-09-07
There is no widely agreed definition of entropy, and consequently Gibbs energy, in open systems far from equilibrium. One recent approach has sought to formulate an entropy and Gibbs energy based on observed scale invariances in geophysical variables, particularly in atmospheric quantities, including the molecules constituting stratospheric chemistry. The Hamiltonian flux dynamics of energy in macroscopic open nonequilibrium systems maps to energy in equilibrium statistical thermodynamics, and corresponding equivalences of scale invariant variables with other relevant statistical mechanical variables such as entropy, Gibbs energy, and 1/(k Boltzmann T), are not just formally analogous but are also mappings. Three proof-of-concept representative examples from available adequate stratospheric chemistry observations-temperature, wind speed and ozone-are calculated, with the aim of applying these mappings and equivalences. Potential applications of the approach to scale invariant observations from the literature, involving scales from molecular through laboratory to astronomical, are considered. Theoretical support for the approach from the literature is discussed.
Gibbs Energy Modeling of Digenite and Adjacent Solid-State Phases
Waldner, Peter
2017-08-01
All sulfur potential and phase diagram data available in the literature for solid-state equilibria related to digenite have been assessed. Thorough thermodynamic analysis at 1 bar total pressure has been performed. A three-sublattice approach has been developed to model the Gibbs energy of digenite as a function of composition and temperature using the compound energy formalism. The Gibbs energies of the adjacent solid-state phases covelitte and high-temperature chalcocite are also modeled treating both sulfides as stoichiometric compounds. The novel model for digenite offers new interpretation of experimental data, may contribute from a thermodynamic point of view to the elucidation of the role of copper species within the crystal structure and allows extrapolation to composition regimes richer in copper than stoichiometric digenite Cu2S. Preliminary predictions into the ternary Cu-Fe-S system at 1273 K (1000 °C) using the Gibbs energy model of digenite for calculating its iron solubility are promising.
Gibbs free energy of formation of liquid lanthanide-bismuth alloys
International Nuclear Information System (INIS)
Sheng Jiawei; Yamana, Hajimu; Moriyama, Hirotake
2001-01-01
The linear free energy relationship developed by Sverjensky and Molling provides a way to predict Gibbs free energies of liquid Ln-Bi alloys formation from the known thermodynamic properties of aqueous trivalent lanthanides (Ln 3(5(6+ ). The Ln-Bi alloys are divided into two isostructural families named as the LnBi 2 (Ln=La, Ce, Pr, Nd and Pm) and LnBi (Ln=Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb). The calculated Gibbs free energy values are well agreed with experimental data
Determination of standard molar Gibbs energy of formation of Sm6UO12(s)
International Nuclear Information System (INIS)
Sahu, Manjulata; Dash, Smruti
2015-01-01
The standard molar Gibbs energies of formation of Sm 6 UO 12 (s) have been measured using an oxygen concentration cell with yttria stabilized zirconia as solid electrolyte. Δ f G o m (T) for Sm 6 UO 12 (s) has been calculated using the measured and required thermodynamic data from the literature. The calculated Gibbs energy expression in the temperature range 899 to 1127 K can be given as: Δ f G o m (Nd 6 UO 12 , s,T)/(±2.3) kJ∙ mol -1 = -6681 +1.099 (T/K) (899-1127 K)(T/K). (author)
Experimental Determination of Third Derivative of the Gibbs Free Energy, G II
DEFF Research Database (Denmark)
Koga, Yoshikata; Westh, Peter; Inaba, Akira
2010-01-01
We have been evaluating third derivative quantities of the Gibbs free energy, G, by graphically differentiating the second derivatives that are accessible experimentally, and demonstrated their power in elucidating the mixing schemes in aqueous solutions. Here we determine directly one of the third...
International Nuclear Information System (INIS)
Del' Pino, Kh.; Chukurov, P.M.; Drakin, S.I.
1980-01-01
Analyzed are the results of experimental depermination of formation enthalpies of waterless nitrates of lanthane cerium, praseodymium, neodymium and samarium. Using method of comparative calculation computed are enthalpies of formation of waterless lanthanide and yttrium nitrates. Calculated values of enthalpies and Gibbs energies of waterless lanthanide nitrate formation are tabulated
Estimates of Gibbs free energies of formation of chlorinated aliphatic compounds
Dolfing, Jan; Janssen, Dick B.
1994-01-01
The Gibbs free energy of formation of chlorinated aliphatic compounds was estimated with Mavrovouniotis' group contribution method. The group contribution of chlorine was estimated from the scarce data available on chlorinated aliphatics in the literature, and found to vary somewhat according to the
The Gibbs Energy Basis and Construction of Boiling Point Diagrams in Binary Systems
Smith, Norman O.
2004-01-01
An illustration of how excess Gibbs energies of the components in binary systems can be used to construct boiling point diagrams is given. The underlying causes of the various types of behavior of the systems in terms of intermolecular forces and the method of calculating the coexisting liquid and vapor compositions in boiling point diagrams with…
International Nuclear Information System (INIS)
Genderen, A.C.G. van; Weijden, C.H. van der
1984-01-01
For a group of minerals containing a common anion there exists a linear relationship between two parameters called ΔO and ΔF.ΔO is defined as the difference between the Gibbs energy of formation of a solid oxide and the Gibbs energy of formation of its aqueous cation, while ΔF is defined as the Gibbs energy of reaction of the formation of a mineral from the constituting oxide(s) and the acid. Using the Gibbs energies of formation of a number of known minerals the corresponding ΔO's and ΔF's were calculated and with the resulting regression equation it is possible to predict values for the Gibbs energies of formation of other minerals containing the same anion. This was done for 29 minerals containing the uranyl-ion together with phosphate, vanadate, arsenate or carbonate. (orig.)
Gibbs free energy of formation of lanthanum rhodate by quadrupole mass spectrometer
International Nuclear Information System (INIS)
Prasad, R.; Banerjee, Aparna; Venugopal, V.
2003-01-01
The ternary oxide in the system La-Rh-O is of considerable importance because of its application in catalysis. Phase equilibria in the pseudo-binary system La 2 O 3 -Rh 2 O 3 has been investigated by Shevyakov et. al. Gibbs free energy of LaRhO 3 (s) was determined by Jacob et. al. using a solid state Galvanic cell in the temperature range 890 to 1310 K. No other thermodynamic data were available in the literature. Hence it was decided to determine Gibbs free energy of formation of LaRhO 3 (s) by an independent technique, viz. quadrupole mass spectrometer (QMS) coupled with a Knudsen effusion cell and the results are presented
Molar Surface Gibbs Energy of the Aqueous Solution of Ionic Liquid [C4mim][Oac
Institute of Scientific and Technical Information of China (English)
TONG Jing; ZHENG Xu; TONG Jian; QU Ye; LIU Lu; LI Hui
2017-01-01
The values of density and surface tension for aqueous solution of ionic liquid(IL) 1-butyl-3-methylimidazolium acetate([C4mim][OAc]) with various molalities were measured in the range of 288.15-318.15 K at intervals of 5 K.On the basis of thermodynamics,a semi-empirical model-molar surface Gibbs energy model of the ionic liquid solution that could be used to predict the surface tension or molar volume of solutions was put forward.The predicted values of the surface tension for aqueous [C4im][OAc] and the corresponding experimental ones were highly correlated and extremely similar.In terms of the concept of the molar Gibbs energy,a new E(o)tv(o)s equation was obtained and each parameter of the new equation has a clear physical meaning.
The thermodynamic properties of the upper continental crust: Exergy, Gibbs free energy and enthalpy
International Nuclear Information System (INIS)
Valero, Alicia; Valero, Antonio; Vieillard, Philippe
2012-01-01
This paper shows a comprehensive database of the thermodynamic properties of the most abundant minerals of the upper continental crust. For those substances whose thermodynamic properties are not listed in the literature, their enthalpy and Gibbs free energy are calculated with 11 different estimation methods described in this study, with associated errors of up to 10% with respect to values published in the literature. Thanks to this procedure we have been able to make a first estimation of the enthalpy, Gibbs free energy and exergy of the bulk upper continental crust and of each of the nearly 300 most abundant minerals contained in it. Finally, the chemical exergy of the continental crust is compared to the exergy of the concentrated mineral resources. The numbers obtained indicate the huge chemical exergy wealth of the crust: 6 × 10 6 Gtoe. However, this study shows that approximately only 0.01% of that amount can be effectively used by man.
Direct measurements of the Gibbs free energy of OH using a CW tunable laser
Killinger, D. K.; Wang, C. C.
1979-01-01
The paper describes an absorption measurement for determining the Gibbs free energy of OH generated in a mixture of water and oxygen vapor. These measurements afford a direct verification of the accuracy of thermochemical data of H2O at high temperatures and pressures. The results indicate that values for the heat capacity of H2O obtained through numerical computations are correct within an experimental uncertainty of 0.15 cal/mole K.
Standard Gibbs free energies for transfer of actinyl ions at the aqueous/organic solution interface
International Nuclear Information System (INIS)
Kitatsuji, Yoshihiro; Okugaki, Tomohiko; Kasuno, Megumi; Kubota, Hiroki; Maeda, Kohji; Kimura, Takaumi; Yoshida, Zenko; Kihara, Sorin
2011-01-01
Research highlights: → Standard Gibbs free energies for ion-transfer of tri- to hexavalent actinide ions. → Determination is based on distribution method combined with ion-transfer voltammetry. → Organic solvents examined are nitrobenzene, DCE, benzonitrile, acetophenone and NPOE. → Gibbs free energies of U(VI), Np(VI) and Pu(VI) are similar to each other. → Gibbs free energies of Np(V) is very large, comparing with ordinary monovalent cations. - Abstract: Standard Gibbs free energies for transfer (ΔG tr 0 ) of actinyl ions (AnO 2 z+ ; z = 2 or 1; An: U, Np, or Pu) between an aqueous solution and an organic solution were determined based on distribution method combined with voltammetry for ion transfer at the interface of two immiscible electrolyte solutions. The organic solutions examined were nitrobenzene, 1,2-dichloroethane, benzonitrile, acetophenone, and 2-nitrophenyl octyl ether. Irrespective of the type of organic solutions, ΔG tr 0 of UO 2 2+ ,NpO 2 2+ , and PuO 2 2+ were nearly equal to each other and slightly larger than that of Mg 2+ . The ΔG tr 0 of NpO 2 + was extraordinary large compared with those of ordinary monovalent cations. The dependence of ΔG tr 0 of AnO 2 z+ on the type of organic solutions was similar to that of H + or Mg 2+ . The ΔG tr 0 of An 3+ and An 4+ were also discussed briefly.
Hanson, Robert M.; Riley, Patrick; Schwinefus, Jeff; Fischer, Paul J.
2008-01-01
The use of qualitative graphs of Gibbs energy versus temperature is described in the context of chemical demonstrations involving phase changes and colligative properties at the general chemistry level. (Contains 5 figures and 1 note.)
Solid oxide galvanic cell for determination of Gibbs energy of formation of Tb6UO12(s)
International Nuclear Information System (INIS)
Sahu, Manjulata; Dash, Smruti
2013-01-01
Citrate-nitrate combustion method was used to synthesise Tb 6 UO 12 (s). Gibbs energy of formation of Tb 6 UO 12 (s) was measured using solid oxide galvanic cell in the temperature range 957-1175 K. (author)
International Nuclear Information System (INIS)
Xiong Shiyun; Qi Weihong; Huang Baiyun; Wang Mingpu; Li Yejun
2010-01-01
The Debye model of Helmholtz free energy for bulk material is generalized to Gibbs free energy (GFE) model for nanomaterial, while a shape factor is introduced to characterize the shape effect on GFE. The structural transitions of Ti and Zr nanoparticles are predicted based on GFE. It is further found that GFE decreases with the shape factor and increases with decreasing of the particle size. The critical size of structural transformation for nanoparticles goes up as temperature increases in the absence of change in shape factor. For specified temperature, the critical size climbs up with the increase of shape factor. The present predictions agree well with experiment values.
Excess Gibbs energy for six binary solid solutions of molecularly simple substances
Energy Technology Data Exchange (ETDEWEB)
Lobo, L J; Staveley, L A.K.
1985-01-01
In this paper we apply the method developed in a previous study of Ar + CH/sub 4/ to the evaluation of the excess Gibbs energy G /SUP E.S/ for solid solutions of two molecularly simple components. The method depends on combining information on the excess Gibbs energy G /SUP E.L/ for the liquid mixture of the two components with a knowledge of the (T, x) solid-liquid phase diagram. Certain thermal properties o the pure substances are also needed. G /SUP E.S/ has been calculated for binary mixtures of Ar + Kr, Kr + CH/sub 4/, CO + N/sub 2/, Kr + Xe, Ar + N/sub 2/, and Ar + CO. In general, but not always, the solid mixtures are more non-ideal than the liquid mixtures of the same composition at the same temperature. Except for the Kr + CH/sub 4/ system, the ratio r = G /SUP E.S/ /G /SUP E.L/ is larger the richer the solution in the component with the smaller molecules.
Gibbs Free Energy of Formation for Selected Platinum Group Minerals (PGM
Directory of Open Access Journals (Sweden)
Spiros Olivotos
2016-01-01
Full Text Available Thermodynamic data for platinum group (Os, Ir, Ru, Rh, Pd and Pt minerals are very limited. The present study is focused on the calculation of the Gibbs free energy of formation (ΔfG° for selected PGM occurring in layered intrusions and ophiolite complexes worldwide, applying available experimental data on their constituent elements at their standard state (ΔG = G(species − ΔG(elements, using the computer program HSC Chemistry software 6.0. The evaluation of the accuracy of the calculation method was made by the calculation of (ΔGf of rhodium sulfide phases. The calculated values were found to be ingood agreement with those measured in the binary system (Rh + S as a function of temperature by previous authors (Jacob and Gupta (2014. The calculated Gibbs free energy (ΔfG° followed the order RuS2 < (Ir,OsS2 < (Pt, PdS < (Pd, PtTe2, increasing from compatible to incompatible noble metals and from sulfides to tellurides.
International Nuclear Information System (INIS)
Tremaine, P.R.
1979-01-01
Methods for calculating high-temprature Gibbs free energies of mononuclear cations and anions from room-temperature data are reviewed. Emphasis is given to species required for oxide solubility calculations relevant to mass transport situations in the nuclear industry. Free energies predicted by each method are compared to selected values calculated from recently reported solubility studies and other literature data. Values for monatomic ions estimated using the assumption anti C 0 p(T) = anti C 0 p(298) agree best with experiment to 423 K. From 423 K to 523 K, free energies from an electrostatic model for ion hydration are more accurate. Extrapolations for hydrolyzed species are limited by a lack of room-temperature entropy data and expressions for estimating these entropies are discussed. (orig.) [de
Smith, J. A.; Froyd, K. D.; Toon, O. B.
2012-12-01
We construct tables of reaction enthalpies and entropies for the association reactions involving sulfuric acid vapor, water vapor, and the bisulfate ion. These tables are created from experimental measurements and quantum chemical calculations for molecular clusters and a classical thermodynamic model for larger clusters. These initial tables are not thermodynamically consistent. For example, the Gibbs free energy of associating a cluster consisting of one acid molecule and two water molecules depends on the order in which the cluster was assembled: add two waters and then the acid or add an acid and a water and then the second water. We adjust the values within the tables using the method of Lagrange multipliers to minimize the adjustments and produce self-consistent Gibbs free energy surfaces for the neutral clusters and the charged clusters. With the self-consistent Gibbs free energy surfaces, we calculate size distributions of neutral and charged clusters for a variety of atmospheric conditions. Depending on the conditions, nucleation can be dominated by growth along the neutral channel or growth along the ion channel followed by ion-ion recombination.
International Nuclear Information System (INIS)
Sahu, Manjulata; Dash, Smruti
2011-01-01
The standard molar Gibbs energies of formation of Nd 6 UO 12 (s) have been measured using an oxygen concentration cell with yttria stabilized zirconia as solid electrolyte. Δ f G m o (T) for Nd 6 UO 12 (s) has been calculated using the measured and required thermodynamic data from the literature. The calculated Gibbs energy expression can be given as: Δ f G m o (Nd 6 UO 12 , s,T)/(± 2.3) kJmol -1 = -6660.1+1.0898 (T/K). (author)
Generalized Gibbs distribution and energy localization in the semiclassical FPU problem
Hipolito, Rafael; Danshita, Ippei; Oganesyan, Vadim; Polkovnikov, Anatoli
2011-03-01
We investigate dynamics of the weakly interacting quantum mechanical Fermi-Pasta-Ulam (qFPU) model in the semiclassical limit below the stochasticity threshold. Within this limit we find that initial quantum fluctuations lead to the damping of FPU oscillations and relaxation of the system to a slowly evolving steady state with energy localized within few momentum modes. We find that in large systems this state can be described by the generalized Gibbs ensemble (GGE), with the Lagrange multipliers being very weak functions of time. This ensembles gives accurate description of the instantaneous correlation functions, both quadratic and quartic. Based on these results we conjecture that GGE generically appears as a prethermalized state in weakly non-integrable systems.
Standard molar Gibbs free energy of formation of URh3(s)
International Nuclear Information System (INIS)
Prasad, Rajendra; Sayi, Y.S.; Radhakrishna, J.; Yadav, C.S.; Shankaran, P.S.; Chhapru, G.C.
1992-01-01
Equilibrium partial pressures of CO(g) over the system (UO 2 (s) + C(s) + Rh(s) + URh 3 (s)) were measured in the temperature range 1327 - 1438 K. Standard Gibbs molar free energy of formation of URh 3 (Δ f G o m ) in the above temperature range can be expressed as Δ f G o m (URh 3 ,s,T)+-3.0(kJ/mol)= -348.165 + 0.03144 T(K). The second and third law enthalpy of formation, ΔfH o m (URh 3 ,s,298.15 K) are (-318.4 +- 3.0) and (298.3 +- 2.5) kJ/mol respectively. (author). 7 refs., 3 tabs
The Gibbs free energy of homogeneous nucleation: From atomistic nuclei to the planar limit.
Cheng, Bingqing; Tribello, Gareth A; Ceriotti, Michele
2017-09-14
In this paper we discuss how the information contained in atomistic simulations of homogeneous nucleation should be used when fitting the parameters in macroscopic nucleation models. We show how the number of solid and liquid atoms in such simulations can be determined unambiguously by using a Gibbs dividing surface and how the free energy as a function of the number of solid atoms in the nucleus can thus be extracted. We then show that the parameters (the chemical potential, the interfacial free energy, and a Tolman correction) of a model based on classical nucleation theory can be fitted using the information contained in these free-energy profiles but that the parameters in such models are highly correlated. This correlation is unfortunate as it ensures that small errors in the computed free energy surface can give rise to large errors in the extrapolated properties of the fitted model. To resolve this problem we thus propose a method for fitting macroscopic nucleation models that uses simulations of planar interfaces and simulations of three-dimensional nuclei in tandem. We show that when the chemical potentials and the interface energy are pinned to their planar-interface values, more precise estimates for the Tolman length are obtained. Extrapolating the free energy profile obtained from small simulation boxes to larger nuclei is thus more reliable.
DEFF Research Database (Denmark)
Ulstrup, Jens
1999-01-01
We discuss a simple model for the environmental reorganisation Gibbs free energy, E-r, in electron transfer between a metalloprotein and a small reaction partner. The protein is represented as a dielectric globule with low dielectric constant, the metal centres as conducting spheres, all embedded...
Gary, Ronald K.
2004-01-01
The concentration dependence of (delta)S term in the Gibbs free energy function is described in relation to its application to reversible reactions in biochemistry. An intuitive and non-mathematical argument for the concentration dependence of the (delta)S term in the Gibbs free energy equation is derived and the applicability of the equation to…
Gibbs Free-Energy Gradient along the Path of Glucose Transport through Human Glucose Transporter 3.
Liang, Huiyun; Bourdon, Allen K; Chen, Liao Y; Phelix, Clyde F; Perry, George
2018-06-11
Fourteen glucose transporters (GLUTs) play essential roles in human physiology by facilitating glucose diffusion across the cell membrane. Due to its central role in the energy metabolism of the central nervous system, GLUT3 has been thoroughly investigated. However, the Gibbs free-energy gradient (what drives the facilitated diffusion of glucose) has not been mapped out along the transport path. Some fundamental questions remain. Here we present a molecular dynamics study of GLUT3 embedded in a lipid bilayer to quantify the free-energy profile along the entire transport path of attracting a β-d-glucose from the interstitium to the inside of GLUT3 and, from there, releasing it to the cytoplasm by Arrhenius thermal activation. From the free-energy profile, we elucidate the unique Michaelis-Menten characteristics of GLUT3, low K M and high V MAX , specifically suitable for neurons' high and constant demand of energy from their low-glucose environments. We compute GLUT3's binding free energy for β-d-glucose to be -4.6 kcal/mol in agreement with the experimental value of -4.4 kcal/mol ( K M = 1.4 mM). We also compute the hydration energy of β-d-glucose, -18.0 kcal/mol vs the experimental data, -17.8 kcal/mol. In this, we establish a dynamics-based connection from GLUT3's crystal structure to its cellular thermodynamics with quantitative accuracy. We predict equal Arrhenius barriers for glucose uptake and efflux through GLUT3 to be tested in future experiments.
Directory of Open Access Journals (Sweden)
Zhihua Wang
2017-05-01
Full Text Available Crude oil is generally produced with water, and the water cut produced by oil wells is increasingly common over their lifetime, so it is inevitable to create emulsions during oil production. However, the formation of emulsions presents a costly problem in surface process particularly, both in terms of transportation energy consumption and separation efficiency. To deal with the production and operational problems which are related to crude oil emulsions, especially to ensure the separation and transportation of crude oil-water systems, it is necessary to better understand the emulsification mechanism of crude oil under different conditions from the aspects of bulk and interfacial properties. The concept of shearing energy was introduced in this study to reveal the driving force for emulsification. The relationship between shearing stress in the flow field and interfacial tension (IFT was established, and the correlation between shearing energy and interfacial Gibbs free energy was developed. The potential of the developed correlation model was validated using the experimental and field data on emulsification behavior. It was also shown how droplet deformation could be predicted from a random deformation degree and orientation angle. The results indicated that shearing energy as the energy produced by shearing stress working in the flow field is the driving force activating the emulsification behavior. The deformation degree and orientation angle of dispersed phase droplet are associated with the interfacial properties, rheological properties and the experienced turbulence degree. The correlation between shearing stress and IFT can be quantified if droplet deformation degree vs. droplet orientation angle data is available. When the water cut is close to the inversion point of waxy crude oil emulsion, the interfacial Gibbs free energy change decreased and the shearing energy increased. This feature is also presented in the special regions where
Naumov, V. V.; Isaeva, V. A.; Kuzina, E. N.; Sharnin, V. A.
2012-12-01
Gibbs energies for the transfer of glycylglycine and glycylglycinate ions from water to water-dimethylsulfoxide solvents are determined from the interface distribution of substances between immiscible phases in the composition range of 0.00 to 0.20 molar fractions of DMSO at 298.15 K. It is shown that with a rise in the concentration of nonaqueous components in solution, we observe the solvation of dipeptide and its anion, due mainly to the destabilization of the carboxyl group.
Phase relations and gibbs energies in the system Mn-Rh-O
Jacob, K. T.; Sriram, M. V.
1994-07-01
Phase relations in the system Mn-Rh-O are established at 1273 K by equilibrating different compositions either in evacuated quartz ampules or in pure oxygen at a pressure of 1.01 × 105 Pa. The quenched samples are examined by optical microscopy, X-ray diffraction, and energy-dispersive X-ray analysis (EDAX). The alloys and intermetallics in the binary Mn-Rh system are found to be in equilibrium with MnO. There is only one ternary compound, MnRh2O4, with normal spinel structure in the system. The compound Mn3O4 has a tetragonal structure at 1273 K. A solid solution is formed between MnRh2O4 and Mn3O4. The solid solution has the cubic structure over a large range of composition and coexists with metallic rhodium. The partial pressure of oxygen corresponding to this two-phase equilibrium is measured as a function of the composition of the spinel solid solution and temperature. A new solid-state cell, with three separate electrode compartments, is designed to measure accurately the chemical potential of oxygen in the two-phase mixture, Rh + Mn3-2xRh2xO4, which has 1 degree of freedom at constant temperature. From the electromotive force (emf), thermodynamic mixing properties of the Mn3O4-MnRh2O4 solid solution and Gibbs energy of formation of MnRh2O4 are deduced. The activities exhibit negative deviations from Raoult’s law for most of the composition range, except near Mn3O4, where a two-phase region exists. In the cubic phase, the entropy of mixing of the two Rh3+ and Mn3+ ions on the octahedral site of the spinel is ideal, and the enthalpy of mixing is positive and symmetric with respect to composition. For the formation of the spinel (sp) from component oxides with rock salt (rs) and orthorhombic (orth) structures according to the reaction, MnO (rs) + Rh2O3 (orth) → MnRh2O4 (sp), ΔG° = -49,680 + 1.56T (±500) J mol-1 The oxygen potentials corresponding to MnO + Mn3O4 and Rh + Rh2O3 equilibria are also obtained from potentiometric measurements on galvanic
Minimal nuclear energy density functional
Bulgac, Aurel; Forbes, Michael McNeil; Jin, Shi; Perez, Rodrigo Navarro; Schunck, Nicolas
2018-04-01
We present a minimal nuclear energy density functional (NEDF) called "SeaLL1" that has the smallest number of possible phenomenological parameters to date. SeaLL1 is defined by seven significant phenomenological parameters, each related to a specific nuclear property. It describes the nuclear masses of even-even nuclei with a mean energy error of 0.97 MeV and a standard deviation of 1.46 MeV , two-neutron and two-proton separation energies with rms errors of 0.69 MeV and 0.59 MeV respectively, and the charge radii of 345 even-even nuclei with a mean error ɛr=0.022 fm and a standard deviation σr=0.025 fm . SeaLL1 incorporates constraints on the equation of state (EoS) of pure neutron matter from quantum Monte Carlo calculations with chiral effective field theory two-body (NN ) interactions at the next-to-next-to-next-to leading order (N3LO) level and three-body (NNN ) interactions at the next-to-next-to leading order (N2LO) level. Two of the seven parameters are related to the saturation density and the energy per particle of the homogeneous symmetric nuclear matter, one is related to the nuclear surface tension, two are related to the symmetry energy and its density dependence, one is related to the strength of the spin-orbit interaction, and one is the coupling constant of the pairing interaction. We identify additional phenomenological parameters that have little effect on ground-state properties but can be used to fine-tune features such as the Thomas-Reiche-Kuhn sum rule, the excitation energy of the giant dipole and Gamow-Teller resonances, the static dipole electric polarizability, and the neutron skin thickness.
Phase relations and Gibbs energies of spinel phases and solid solutions in the system Mg-Rh-O
Energy Technology Data Exchange (ETDEWEB)
Jacob, K.T., E-mail: katob@materials.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science, Bangalore 560 012 (India); Prusty, Debadutta [Department of Materials Engineering, Indian Institute of Science, Bangalore 560 012 (India); Kale, G.M. [Institute for Materials Research, University of Leeds, Leeds, LS2 9JT (United Kingdom)
2012-02-05
Highlights: Black-Right-Pointing-Pointer Refinement of phase diagram for the system Mg-Rh-O and thermodynamic data for spinel compounds MgRh{sub 2}O{sub 4} and Mg{sub 2}RhO{sub 4} is presented. Black-Right-Pointing-Pointer A solid-state electrochemical cell is used for thermodynamic measurement. Black-Right-Pointing-Pointer An advanced design of the solid-state electrochemical cell incorporating buffer electrodes is deployed to minimize polarization of working electrode. Black-Right-Pointing-Pointer Regular solution model for the spinel solid solution MgRh{sub 2}O{sub 4} - Mg{sub 2}RhO{sub 4} based on ideal mixing of cations on the octahedral site is proposed. Black-Right-Pointing-Pointer Factors responsible for stabilization of tetravalent rhodium in spinel compounds are identified. - Abstract: Pure stoichiometric MgRh{sub 2}O{sub 4} could not be prepared by solid state reaction from an equimolar mixture of MgO and Rh{sub 2}O{sub 3} in air. The spinel phase formed always contained excess of Mg and traces of Rh or Rh{sub 2}O{sub 3}. The spinel phase can be considered as a solid solution of Mg{sub 2}RhO{sub 4} in MgRh{sub 2}O{sub 4}. The compositions of the spinel solid solution in equilibrium with different phases in the ternary system Mg-Rh-O were determined by electron probe microanalysis. The oxygen potential established by the equilibrium between Rh + MgO + Mg{sub 1+x}Rh{sub 2-x}O{sub 4} was measured as a function of temperature using a solid-state cell incorporating yttria-stabilized zirconia as an electrolyte and pure oxygen at 0.1 MPa as the reference electrode. To avoid polarization of the working electrode during the measurements, an improved design of the cell with a buffer electrode was used. The standard Gibbs energies of formation of MgRh{sub 2}O{sub 4} and Mg{sub 2}RhO{sub 4} were deduced from the measured electromotive force (e.m.f.) by invoking a model for the spinel solid solution. The parameters of the model were optimized using the measured
Gibbs Sampler-Based λ-Dynamics and Rao-Blackwell Estimator for Alchemical Free Energy Calculation.
Ding, Xinqiang; Vilseck, Jonah Z; Hayes, Ryan L; Brooks, Charles L
2017-06-13
λ-dynamics is a generalized ensemble method for alchemical free energy calculations. In traditional λ-dynamics, the alchemical switch variable λ is treated as a continuous variable ranging from 0 to 1 and an empirical estimator is utilized to approximate the free energy. In the present article, we describe an alternative formulation of λ-dynamics that utilizes the Gibbs sampler framework, which we call Gibbs sampler-based λ-dynamics (GSLD). GSLD, like traditional λ-dynamics, can be readily extended to calculate free energy differences between multiple ligands in one simulation. We also introduce a new free energy estimator, the Rao-Blackwell estimator (RBE), for use in conjunction with GSLD. Compared with the current empirical estimator, the advantage of RBE is that RBE is an unbiased estimator and its variance is usually smaller than the current empirical estimator. We also show that the multistate Bennett acceptance ratio equation or the unbinned weighted histogram analysis method equation can be derived using the RBE. We illustrate the use and performance of this new free energy computational framework by application to a simple harmonic system as well as relevant calculations of small molecule relative free energies of solvation and binding to a protein receptor. Our findings demonstrate consistent and improved performance compared with conventional alchemical free energy methods.
Size Fluctuations of Near Critical Nuclei and Gibbs Free Energy for Nucleation of BDA on Cu(001)
Schwarz, Daniel; van Gastel, Raoul; Zandvliet, Harold J. W.; Poelsema, Bene
2012-07-01
We present a low-energy electron microscopy study of nucleation and growth of BDA on Cu(001) at low supersaturation. At sufficiently high coverage, a dilute BDA phase coexists with c(8×8) crystallites. The real-time microscopic information allows a direct visualization of near-critical nuclei, determination of the supersaturation and the line tension of the crystallites, and, thus, derivation of the Gibbs free energy for nucleation. The resulting critical nucleus size nicely agrees with the measured value. Nuclei up to 4-6 times larger still decay with finite probability, urging reconsideration of the classic perception of a critical nucleus.
Gibbs free-energy difference between the glass and crystalline phases of a Ni-Zr alloy
Ohsaka, K.; Trinh, E. H.; Holzer, J. C.; Johnson, W. L.
1993-01-01
The heats of eutectic melting and devitrification, and the specific heats of the crystalline, glass, and liquid phases have been measured for a Ni24Zr76 alloy. The data are used to calculate the Gibbs free-energy difference, Delta G(AC), between the real glass and the crystal on an assumption that the liquid-glass transition is second order. The result shows that Delta G(AC) continuously increases as the temperature decreases in contrast to the ideal glass case where Delta G(AC) is assumed to be independent of temperature.
Gibbs free energy difference between the undercooled liquid and the beta phase of a Ti-Cr alloy
Ohsaka, K.; Trinh, E. H.; Holzer, J. C.; Johnson, W. L.
1992-01-01
The heat of fusion and the specific heats of the solid and liquid have been experimentally determined for a Ti60Cr40 alloy. The data are used to evaluate the Gibbs free energy difference, delta-G, between the liquid and the beta phase as a function of temperature to verify a reported spontaneous vitrification (SV) of the beta phase in Ti-Cr alloys. The results show that SV of an undistorted beta phase in the Ti60Cr40 alloy at 873 K is not feasible because delta-G is positive at the temperature. However, delta-G may become negative with additional excess free energy to the beta phase in the form of defects.
Grazhdan, K. V.; Gamov, G. A.; Dushina, S. V.; Sharnin, V. A.
2012-11-01
Coefficients of the interphase distribution of nicotinic acid are determined in aqueous solution systems of ethanol-hexane and DMSO-hexane at 25.0 ± 0.1°C. They are used to calculate the Gibbs energy of the transfer of nicotinic acid from water into aqueous solutions of ethanol and dimethylsulfoxide. The Gibbs energy values for the transfer of the molecular and zwitterionic forms of nicotinic acid are obtained by means of UV spectroscopy. The diametrically opposite effect of the composition of binary solvents on the transfer of the molecular and zwitterionic forms of nicotinic acid is noted.
Naumov, Sergej; von Sonntag, Clemens
2011-11-01
Free radicals are common intermediates in the chemistry of ozone in aqueous solution. Their reactions with ozone have been probed by calculating the standard Gibbs free energies of such reactions using density functional theory (Jaguar 7.6 program). O(2) reacts fast and irreversibly only with simple carbon-centered radicals. In contrast, ozone also reacts irreversibly with conjugated carbon-centered radicals such as bisallylic (hydroxycylohexadienyl) radicals, with conjugated carbon/oxygen-centered radicals such as phenoxyl radicals, and even with nitrogen- oxygen-, sulfur-, and halogen-centered radicals. In these reactions, further ozone-reactive radicals are generated. Chain reactions may destroy ozone without giving rise to products other than O(2). This may be of importance when ozonation is used in pollution control, and reactions of free radicals with ozone have to be taken into account in modeling such processes.
International Nuclear Information System (INIS)
Rog, G.; Kucza, W.; Kozlowska-Rog, A.
2004-01-01
The standard Gibbs free energy of formation of LiMnO 2 and LiMn 2 O 4 at the temperatures of (680, 740 and 800) K has been determined with the help of the solid-state galvanic cells involving lithium-β-alumina electrolyte. The equilibrium electrical potentials of cathode containing Li x Mn 2 O 4 spinel, in the composition ranges 0≤x≤1 and 1≤x≤2, vs. metallic lithium in the reversible intercalation galvanic cell have been calculated. The existence of two-voltage plateaus which appeared during charging and discharging processes in reversible intercalation of lithium into Li x Mn 2 O 4 spinel, has been discussed
International Nuclear Information System (INIS)
Jebri, Sonia; Khattech, Ismail; Jemal, Mohamed
2017-01-01
Highlights: • A-type carbonate hydroxyapatites with 0 ⩽ x ⩽ 1 were prepared and characterized by DRX, IR spectroscopy and CHN analysis. • The heat of solution was measured in 9 wt% HNO 3 using an isoperibol calorimeter. • The standard enthalpy of formation was determined by thermochemical cycle. • Gibbs free energy has been deduced by estimating standard entropy of formation. • Carbonatation increases the stability till x = 0.6 mol. - Abstract: « A » type carbonate phosphocalcium hydroxyapatites having the general formula Ca 10 (PO 4 ) 6 (OH) (2-2x) (CO 3 ) x with 0 ⩽ x ⩽ 1, were prepared by solid gas reaction in the temperature range of 700–1000 °C. The obtained materials were characterized by X-ray diffraction and infrared spectroscopy. The carbonate content has been determined by C–H–N analysis. The heat of solution of these products was measured at T = 298 K in 9 wt% nitric acid solution using an isoperibol calorimeter. A thermochemical cycle was proposed and complementary experiences were performed in order to access to the standard enthalpies of formation of these phosphates. The results were compared to those previously obtained on apatites containing strontium and barium and show a decrease with the carbonate amount introduced in the lattice. This quantity becomes more negative as the ratio of substitution increases. Estimation of the entropy of formation allowed the determination of standard Gibbs free energy of formation of these compounds. The study showed that the substitution of hydroxyl by carbonate ions contributes to the stabilisation of the apatite structure.
Privat, Romain; Jaubert, Jean-Noe¨l; Berger, Etienne; Coniglio, Lucie; Lemaitre, Ce´cile; Meimaroglou, Dimitrios; Warth, Vale´rie
2016-01-01
Robust and fast methods for chemical or multiphase equilibrium calculation are routinely needed by chemical-process engineers working on sizing or simulation aspects. Yet, while industrial applications essentially require calculation tools capable of discriminating between stable and nonstable states and converging to nontrivial solutions,…
International Nuclear Information System (INIS)
Xu, H.; Wang, Y.
1999-01-01
In this letter, a linear free energy relationship is used to predict the Gibbs free energies of formation of crystalline phases of pyrochlore and zirconolite families with stoichiometry of MCaTi 2 O 7 (or, CaMTi 2 O 7 ,) from the known thermodynamic properties of aqueous tetravalent cations (M 4+ ). The linear free energy relationship for tetravalent cations is expressed as ΔG f,M v X 0 =a M v X ΔG n,M 4+ 0 +b M v X +β M v X r M 4+ , where the coefficients a M v X , b M v X , and β M v X characterize a particular structural family of M v X, r M 4+ is the ionic radius of M 4+ cation, ΔG f,M v X 0 is the standard Gibbs free energy of formation of M v X, and ΔG n,M 4+ 0 is the standard non-solvation energy of cation M 4+ . The coefficients for the structural family of zirconolite with the stoichiometry of M 4+ CaTi 2 O 7 are estimated to be: a M v X =0.5717, b M v X =-4284.67 (kJ/mol), and β M v X =27.2 (kJ/mol nm). The coefficients for the structural family of pyrochlore with the stoichiometry of M 4+ CaTi 2 O 7 are estimated to be: a M v X =0.5717, b M v X =-4174.25 (kJ/mol), and β M v X =13.4 (kJ/mol nm). Using the linear free energy relationship, the Gibbs free energies of formation of various zirconolite and pyrochlore phases are calculated. (orig.)
Blandamer, Michael J.; Cullis, Paul M.; Soldi, L. Giorgio; Engberts, Jan B.F.N.; Kacperska, Anna; Os, Nico M. van
1995-01-01
Micellar colloids are distinguished from other colloids by their association-dissociation equilibrium in solution between monomers, counter-ions and micelles. According to classical thermodynamics, the standard Gibbs energy of formation of micelles at fixed temperature and pressure can be related to
Czech Academy of Sciences Publication Activity Database
Langmaier, Jan; Záliš, Stanislav; Samec, Zdeněk; Bovtun, Viktor; Kempa, Martin
2013-01-01
Roč. 87, JAN 2013 (2013), s. 591-598 ISSN 0013-4686 R&D Projects: GA ČR GAP206/11/0707 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : ionic liquid s * cyclic voltammetry * standard Gibbs energy of ion transfer Subject RIV: CG - Electrochemistry Impact factor: 4.086, year: 2013
Size fluctuations of near critical and Gibbs free energy for nucleation of BDA on Cu(001)
Schwarz, Daniel; van Gastel, Raoul; Zandvliet, Henricus J.W.; Poelsema, Bene
2012-01-01
We present a low-energy electron microscopy study of nucleation and growth of BDA on Cu(001) at low supersaturation. At sufficiently high coverage, a dilute BDA phase coexists with c(8×8) crystallites. The real-time microscopic information allows a direct visualization of near-critical nuclei,
Posuvailo, V. M.; Klapkiv, M. D.; Student, M. M.; Sirak, Y. Y.; Pokhmurska, H. V.
2017-03-01
The oxide ceramic coating with copper inclusions was synthesized by the method of plasma electrolytic oxidation (PEO). Calculations of the Gibbs energies of reactions between the plasma channel elements with inclusions of copper and copper oxide were carried out. Two methods of forming the oxide-ceramic coatings on aluminum base in electrolytic plasma with copper inclusions were established. The first method - consist in the introduction of copper into the aluminum matrix, the second - copper oxide. During the synthesis of oxide ceramic coatings plasma channel does not react with copper and copper oxide-ceramic included in the coating. In the second case is reduction of copper oxide in interaction with elements of the plasma channel. The content of oxide-ceramic layer was investigated by X-ray and X-ray microelement analysis. The inclusions of copper, CuAl2, Cu9Al4 in the oxide-ceramic coatings were found. It was established that in the spark plasma channels alongside with the oxidation reaction occurs also the reaction aluminothermic reduction of the metal that allows us to dope the oxide-ceramic coating by metal the isobaric-isothermal potential oxidation of which is less negative than the potential of the aluminum oxide.
Isham, M. A.
1992-01-01
Silicon carbide and silicon nitride are considered for application as structural materials and coating in advanced propulsion systems including nuclear thermal. Three-dimensional Gibbs free energy were constructed for reactions involving these materials in H2 and H2/H2O. Free energy plots are functions of temperature and pressure. Calculations used the definition of Gibbs free energy where the spontaneity of reactions is calculated as a function of temperature and pressure. Silicon carbide decomposes to Si and CH4 in pure H2 and forms a SiO2 scale in a wet atmosphere. Silicon nitride remains stable under all conditions. There was no apparent difference in reaction thermodynamics between ideal and Van der Waals treatment of gaseous species.
International Nuclear Information System (INIS)
Kireev, A.A.; Pak, T.G.; Bezuglyj, V.D.
1996-01-01
Solubilities of KClO 4 , RbClO 4 , CsClO 4 , (CH 3 ) 4 NClO 4 , (C 2 M 5 ) 4 NClO 4 in water and water-acetone mixtures are determined by the method of isothermal saturation at 298.15 K. Dissociation constants of alkali metal perchlorates are found by conductometric method. Solubility products and standard Gibbs energies of transfer of corresponding electrolytes from water into water-acetone solvents are calculated. The character of transfer Gibbs energy dependence on solvent composition is explained by preferred solvation of cations by acetone molecules and anions-by water molecules. Features of tetraalkyl ammonium ions are explained by large changes in energy of cavity formation for these ions
International Nuclear Information System (INIS)
Silverio, Sara C.; Rodriguez, Oscar; Teixeira, Jose A.; Macedo, Eugenia A.
2010-01-01
The Gibbs free energy of transfer of a suitable hydrophobic probe can be regarded as a measure of the relative hydrophobicity of the different phases. The methylene group (CH 2 ) can be considered hydrophobic, and thus be a suitable probe for hydrophobicity. In this work, the partition coefficients of a series of five dinitrophenylated-amino acids were experimentally determined, at 23 o C, in three different tie-lines of the biphasic systems: (UCON + K 2 HPO 4 ), (UCON + potassium phosphate buffer, pH 7), (UCON + KH 2 PO 4 ), (UCON + Na 2 HPO 4 ), (UCON + sodium phosphate buffer, pH 7), and (UCON + NaH 2 PO 4 ). The Gibbs free energy of transfer of CH 2 units were calculated from the partition coefficients and used to compare the relative hydrophobicity of the equilibrium phases. The largest relative hydrophobicity was found for the ATPS formed by dihydrogen phosphate salts.
Gibbs energies of formation of zircon (ZrSiO4), thorite (ThSiO4), and phenacite (Be2SiO4)
International Nuclear Information System (INIS)
Schuiling, R.D.; Vergouwen, L.; Rijst, H. van der
1976-01-01
Zircon, thorite, and phenacite are very refractory compounds which do not yield to solution calorimetry. In In order to obtain approximate Gibbs energies of formation for these minerals, their reactions with a number of silica-undersaturated compounds (silicates or oxides) were studied. Conversely baddeleyite (ZrO 2 ), thorianite (ThO 2 ), and bromellite (BeO) were reacted with the appropriate silicates. As the Gibbs energies of reaction of the undersaturated compounds with SiO 2 are known, the experiments yield the following data: Δ G 298 , 1 /sub bar/ 0 = -459.02 +- 1.04 kcal for zircon, -489.67 +- 1.04 for thorite, and -480.20 +- 1.01 for phenacite
International Nuclear Information System (INIS)
Vecchio, Stefano
2010-01-01
The vapor pressures above the solid hexachlorobenzene (HCB) and above both the solid and liquid 1,2,3,4,5,6-hexachlorocyclohexane (lindane) were determined in the ranges 332-450 K and 347-429 K, respectively, by measuring the mass loss rates recorded by thermogravimetry under both isothermal and nonisothermal conditions. The results obtained were compared with those taken from literature. From the temperature dependence of vapor pressure derived by the experimental thermogravimetry data the molar enthalpies of sublimation Δ cr g H m o ( ) were selected for HCB and lindane as well as the molar enthalpy of vaporization Δ l g H m o ( ) for lindane only, at the middle of the respective temperature intervals. The melting temperatures and the molar enthalpies of fusion Δ cr l H m o (T fus ) of lindane were measured by differential scanning calorimetry. Finally, the standard molar enthalpies of sublimation Δ cr g H m o (298.15 K) were obtained for both chlorinated compounds at the reference temperature of 298.15 K using the Δ cr g H m o ( ), Δ l g H m o ( ) and Δ cr l H m o (T fus ) values, as well as the heat capacity differences between gas and liquid and the heat capacity differences between gas and solid, Δ l g C p,m o and Δ cr g C p,m o , respectively, both estimated by applying a group additivity procedure. Therefore, the averages of the standard (p o = 0.1 MPa) molar enthalpies, entropies and Gibbs energies of sublimation at 298.15 K, have been derived.
International Nuclear Information System (INIS)
Awasthi, Neha; Ritschel, Thomas; Lipowsky, Reinhard; Knecht, Volker
2013-01-01
Highlights: • ΔG and K eq for NO 2 dimerization and NH 3 synthesis calculated via ab-initio methods. • Vis-á-vis experiments, W1 and CCSD(T) are accurate and G3B3 also does quite well. • CBS-APNO most accurate for NH 3 reaction but shows limitations in modeling NO 2 . • Temperature dependence of ΔG and K eq is calculated for the NH 3 reaction. • Good agreement of calculated K eq with experiments and the van’t Hoff approximation. -- Abstract: Standard quantum chemical methods are used for accurate calculation of thermochemical properties such as enthalpies of formation, entropies and Gibbs energies of formation. Equilibrium reactions are widely investigated and experimental measurements often lead to a range of reaction Gibbs energies and equilibrium constants. It is useful to calculate these equilibrium properties from quantum chemical methods in order to address the experimental differences. Furthermore, most standard calculation methods differ in accuracy and feasibility of the system size. Hence, a systematic comparison of equilibrium properties calculated with different numerical algorithms would provide a useful reference. We select two well-known gas phase equilibrium reactions with small molecules: covalent dimer formation of NO 2 (2NO 2 ⇌ N 2 O 4 ) and the synthesis of NH 3 (N 2 + 3 H 2 ⇌ 2NH 3 ). We test four quantum chemical methods denoted by G3B3, CBS-APNO, W1 and CCSD(T) with aug-cc-pVXZ basis sets (X = 2, 3, and 4), to obtain thermochemical data for NO 2 , N 2 O 4 , and NH 3 . The calculated standard formation Gibbs energies Δ f G° are used to calculate standard reaction Gibbs energies Δ r G° and standard equilibrium constants K eq for the two reactions. Standard formation enthalpies Δ f H° are calculated in a more reliable way using high-level methods such as W1 and CCSD(T). Standard entropies S° for the molecules are calculated well within the range of experiments for all methods, however, the values of standard formation
Indian Academy of Sciences (India)
The younger Gibbs grew up in the liberal and academic atmos- phere at Yale, where .... research in the premier European universities at the time when a similar culture ... tion in obscure journals, Gibbs' work did not receive wide recognition in ...
Masuda, Yosuke; Yamaotsu, Noriyuki; Hirono, Shuichi
2017-01-01
In order to predict the potencies of mechanism-based reversible covalent inhibitors, the relationships between calculated Gibbs free energy of hydrolytic water molecule in acyl-trypsin intermediates and experimentally measured catalytic rate constants (k cat ) were investigated. After obtaining representative solution structures by molecular dynamics (MD) simulations, hydration thermodynamics analyses using WaterMap™ were conducted. Consequently, we found for the first time that when Gibbs free energy of the hydrolytic water molecule was lower, logarithms of k cat were also lower. The hydrolytic water molecule with favorable Gibbs free energy may hydrolyze acylated serine slowly. Gibbs free energy of hydrolytic water molecule might be a useful descriptor for computer-aided discovery of mechanism-based reversible covalent inhibitors of hydrolytic enzymes.
Energy Technology Data Exchange (ETDEWEB)
Prasad, T.E. Vittal [Properties Group, Chemical Engineering Laboratory, Indian Institute of Chemical Technology, Hyderabad 500 007 (India); Venkanna, N. [Swamy Ramanandateertha Institute of Science and Technology, Hyderabad 508 004 (India); Kumar, Y. Naveen [Swamy Ramanandateertha Institute of Science and Technology, Hyderabad 508 004 (India); Ashok, K. [Swamy Ramanandateertha Institute of Science and Technology, Hyderabad 508 004 (India); Sirisha, N.M. [Swamy Ramanandateertha Institute of Science and Technology, Hyderabad 508 004 (India); Prasad, D.H.L. [Properties Group, Chemical Engineering Laboratory, Indian Institute of Chemical Technology, Hyderabad 500 007 (India)]. E-mail: dasika@iict.res.in
2007-07-15
Bubble point temperatures at 95.23 kPa, over the entire composition range are measured for the binary mixtures formed by p-cresol with 1,2-dichloroethane, 1,1,2,2-tetrachloroethane trichloroethylene, tetrachloroethylene, and o- , m- , and p-xylenes, making use of a Swietoslawski-type ebulliometer. Liquid phase mole fraction (x {sub 1}) versus bubble point temperature (T) measurements are found to be well represented by the Wilson model. The optimum Wilson parameters are used to calculate the vapor phase composition, activity coefficients, and excess Gibbs free energy. The results are discussed.
Microgrids: Energy management by loss minimization technique
Energy Technology Data Exchange (ETDEWEB)
Basu, A.K. [Electrical Engineering Dept., Jadavpur University & 20/2, Khanpur Road, Kolkata 700047 (India); Chowdhury, S.; Chowdhury, S.P. [Electrical Engineering Department, University of Cape Town & Private Bag X3, Menzies Building, Room-517, Rondebosch, Cape Town 7701 (India)
2011-07-01
Energy management is a techno-economic issue, which dictates, in the context of microgrids, how optimal investment in technology front could bring optimal power quality and reliability (PQR) of supply to the consumers. Investment in distributed energy resources (DERs), with their connection to the utility grid at optimal locations and with optimal sizes, saves energy in the form of line loss reduction. Line loss reduction is the indirect benefit to the microgrid owner who may recover it as an incentive from utility. The present paper focuses on planning of optimal siting and sizing of DERs based on minimization of line loss. Optimal siting is done, here, on the loss sensitivity index (LSI) method and optimal sizing by differential evolution (DE) algorithms, which is, again, compared with particle swarm optimization (PSO) technique. Studies are conducted on 6-bus and 14-bus radial networks under islanded mode of operation with electric demand profile. Islanding helps planning of DER capacity of microgrid, which is self-sufficient to cater its own consumers without utility's support.
Periodic-cylinder vesicle with minimal energy
International Nuclear Information System (INIS)
Xiao-Hua, Zhou
2010-01-01
We give some details about the periodic cylindrical solution found by Zhang and Ou-Yang in [1996 Phys. Rev. E 53 4206] for the general shape equation of vesicle. Three different kinds of periodic cylindrical surfaces and a special closed cylindrical surface are obtained. Using the elliptic functions contained in mathematic, we find that this periodic shape has the minimal total energy for one period when the period–amplitude ratio β ≈ 1.477, and point out that it is a discontinuous deformation between plane and this periodic shape. Our results also are suitable for DNA and multi-walled carbon nanotubes (MWNTs). (cross-disciplinary physics and related areas of science and technology)
Wormholes minimally violating the null energy condition
Energy Technology Data Exchange (ETDEWEB)
Bouhmadi-López, Mariam [Departamento de Física, Universidade da Beira Interior, 6200 Covilhã (Portugal); Lobo, Francisco S N; Martín-Moruno, Prado, E-mail: mariam.bouhmadi@ehu.es, E-mail: fslobo@fc.ul.pt, E-mail: pmmoruno@fc.ul.pt [Centro de Astronomia e Astrofísica da Universidade de Lisboa, Campo Grande, Edifício C8, 1749-016 Lisboa (Portugal)
2014-11-01
We consider novel wormhole solutions supported by a matter content that minimally violates the null energy condition. More specifically, we consider an equation of state in which the sum of the energy density and radial pressure is proportional to a constant with a value smaller than that of the inverse area characterising the system, i.e., the area of the wormhole mouth. This approach is motivated by a recently proposed cosmological event, denoted {sup t}he little sibling of the big rip{sup ,} where the Hubble rate and the scale factor blow up but the cosmic derivative of the Hubble rate does not [1]. By using the cut-and-paste approach, we match interior spherically symmetric wormhole solutions to an exterior Schwarzschild geometry, and analyse the stability of the thin-shell to linearized spherically symmetric perturbations around static solutions, by choosing suitable properties for the exotic material residing on the junction interface radius. Furthermore, we also consider an inhomogeneous generalization of the equation of state considered above and analyse the respective stability regions. In particular, we obtain a specific wormhole solution with an asymptotic behaviour corresponding to a global monopole.
International Nuclear Information System (INIS)
Tang, Ying; Du, Yong; Zhang, Lijun; Yuan, Xiaoming; Kaptay, George
2012-01-01
Highlights: ► An exponential formulation to describe ternary excess Gibbs energy is proposed. ► Theoretical analysis is performed to verify stability of phase using new formulation. ► Al–Mg–Si system and its boundary binaries have been assessed by the new formulation. ► Present calculations for Al–Mg–Si system are more reasonable than previous ones. - Abstract: An exponential formulation was proposed to replace the linear interaction parameter in the Redlich–Kister (R–K) polynomial for the excess Gibbs energy of ternary solution phase. The theoretical analysis indicates that the proposed new exponential formulation can not only avoid the artificial miscibility gap at high temperatures but also describe the ternary system well. A thermodynamic description for the Al–Mg–Si system and its boundary binaries was then performed by using both R–K linear and exponential formulations. The inverted miscibility gaps occurring in the Mg–Si and the Al–Mg–Si systems at high temperatures due to the use of R–K linear polynomials are avoided by using the new formulation. Besides, the thermodynamic properties predicted with the new formulation confirm the general thermodynamic belief that the solution phase approaches to the ideal solution at infinite temperatures, which cannot be described with the traditional R–K linear polynomials.
International Nuclear Information System (INIS)
Phadke, Sushil; Shrivastava, Bhakt Darshan; Ujle, S K; Mishra, Ashutosh; Dagaonkar, N
2014-01-01
One of the potential driving forces behind a chemical reaction is favourable a new quantity known as the Gibbs free energy (G) of the system, which reflects the balance between these forces. Ultrasonic velocity and absorption measurements in liquids and liquid mixtures find extensive application to study the nature of intermolecular forces. Ultrasonic velocity measurements have been successfully employed to detect weak and strong molecular interactions present in binary and ternary liquid mixtures. After measuring the density and ultrasonic velocity of aqueous solution of 'Borassus Flabellifier' BF and Adansonia digitata And, we calculated Gibb's energy and intermolecular free length. The velocity of ultrasonic waves was measured, using a multi-frequency ultrasonic interferometer with a high degree of accuracy operating Model M-84 by M/s Mittal Enterprises, New Delhi, at a fixed frequency of 2 MHz. Natural sample 'Borassus Flabellifier' BF fruit pulp and Adansonia digitata AnD powder was collected from Dhar, District of MP, India for this study.
Energy Technology Data Exchange (ETDEWEB)
Sobolev, S. L., E-mail: sobolev@icp.ac.ru [Russian Academy of Sciences, Institute of Problems of Chemical Physics (Russian Federation)
2017-03-15
An analytical model has been developed to describe the influence of solute trapping during rapid alloy solidification on the components of the Gibbs free energy change at the phase interface with emphasis on the solute drag energy. For relatively low interface velocity V < V{sub D}, where V{sub D} is the characteristic diffusion velocity, all the components, namely mixing part, local nonequilibrium part, and solute drag, significantly depend on solute diffusion and partitioning. When V ≥ V{sub D}, the local nonequilibrium effects lead to a sharp transition to diffusionless solidification. The transition is accompanied by complete solute trapping and vanishing solute drag energy, i.e. partitionless and “dragless” solidification.
Optimal Allocation of Renewable Energy Sources for Energy Loss Minimization
Directory of Open Access Journals (Sweden)
Vaiju Kalkhambkar
2017-03-01
Full Text Available Optimal allocation of renewable distributed generation (RDG, i.e., solar and the wind in a distribution system becomes challenging due to intermittent generation and uncertainty of loads. This paper proposes an optimal allocation methodology for single and hybrid RDGs for energy loss minimization. The deterministic generation-load model integrated with optimal power flow provides optimal solutions for single and hybrid RDG. Considering the complexity of the proposed nonlinear, constrained optimization problem, it is solved by a robust and high performance meta-heuristic, Symbiotic Organisms Search (SOS algorithm. Results obtained from SOS algorithm offer optimal solutions than Genetic Algorithm (GA, Particle Swarm Optimization (PSO and Firefly Algorithm (FFA. Economic analysis is carried out to quantify the economic benefits of energy loss minimization over the life span of RDGs.
Directory of Open Access Journals (Sweden)
Tiago Campos Pereira
2007-01-01
Full Text Available The RNA interference (RNAi technique is a recent technology that uses double-stranded RNA molecules to promote potent and specific gene silencing. The application of this technique to molecular biology has increased considerably, from gene function identification to disease treatment. However, not all small interfering RNAs (siRNAs are equally efficient, making target selection an essential procedure. Here we present Strand Analysis (SA, a free online software tool able to identify and classify the best RNAi targets based on Gibbs free energy (deltaG. Furthermore, particular features of the software, such as the free energy landscape and deltaG gradient, may be used to shed light on RNA-induced silencing complex (RISC activity and RNAi mechanisms, which makes the SA software a distinct and innovative tool.
3D motion analysis via energy minimization
Energy Technology Data Exchange (ETDEWEB)
Wedel, Andreas
2009-10-16
This work deals with 3D motion analysis from stereo image sequences for driver assistance systems. It consists of two parts: the estimation of motion from the image data and the segmentation of moving objects in the input images. The content can be summarized with the technical term machine visual kinesthesia, the sensation or perception and cognition of motion. In the first three chapters, the importance of motion information is discussed for driver assistance systems, for machine vision in general, and for the estimation of ego motion. The next two chapters delineate on motion perception, analyzing the apparent movement of pixels in image sequences for both a monocular and binocular camera setup. Then, the obtained motion information is used to segment moving objects in the input video. Thus, one can clearly identify the thread from analyzing the input images to describing the input images by means of stationary and moving objects. Finally, I present possibilities for future applications based on the contents of this thesis. Previous work in each case is presented in the respective chapters. Although the overarching issue of motion estimation from image sequences is related to practice, there is nothing as practical as a good theory (Kurt Lewin). Several problems in computer vision are formulated as intricate energy minimization problems. In this thesis, motion analysis in image sequences is thoroughly investigated, showing that splitting an original complex problem into simplified sub-problems yields improved accuracy, increased robustness, and a clear and accessible approach to state-of-the-art motion estimation techniques. In Chapter 4, optical flow is considered. Optical flow is commonly estimated by minimizing the combined energy, consisting of a data term and a smoothness term. These two parts are decoupled, yielding a novel and iterative approach to optical flow. The derived Refinement Optical Flow framework is a clear and straight-forward approach to
Gibbs-non-Gibbs transitions and vector-valued integration
Zuijlen, van W.B.
2016-01-01
This thesis consists of two distinct topics. The first part of the thesis con- siders Gibbs-non-Gibbs transitions. Gibbs measures describe the macro- scopic state of a system of a large number of components that is in equilib- rium. It may happen that when the system is transformed, for example, by
International Nuclear Information System (INIS)
Lobo, L.Q.; Ferreira, A.G.M.; Fonseca, I.M.A.; Senra, A.M.P.
2006-01-01
The vapour pressure of binary mixtures of hydrogen sulphide with ethane, propane, and n-butane was measured at T=182.33K covering most of the composition range. The excess Gibbs free energy of these mixtures has been derived from the measurements made. For the equimolar mixtures G m E (x 1 =0.5)=(835.5+/-5.8)J.mol -1 for (H 2 S+C 2 H 6 ) (820.1+/-2.4)J.mol -1 for (H 2 S+C 3 H 8 ), and (818.6+/-0.9)J.mol -1 for (H 2 S+n-C 4 H 10 ). The binary mixtures of H 2 S with ethane and with propane exhibit azeotropes, but that with n-butane does not
Radtke, Valentin; Ermantraut, Andreas; Himmel, Daniel; Koslowski, Thorsten; Leito, Ivo; Krossing, Ingo
2018-02-23
Described is a procedure for the thermodynamically rigorous, experimental determination of the Gibbs energy of transfer of single ions between solvents. The method is based on potential difference measurements between two electrochemical half cells with different solvents connected by an ideal ionic liquid salt bridge (ILSB). Discussed are the specific requirements for the IL with regard to the procedure, thus ensuring that the liquid junction potentials (LJP) at both ends of the ILSB are mostly canceled. The remaining parts of the LJPs can be determined by separate electromotive force measurements. No extra-thermodynamic assumptions are necessary for this procedure. The accuracy of the measurements depends, amongst others, on the ideality of the IL used, as shown in our companion paper Part II. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
International Nuclear Information System (INIS)
Cotes, S.; Fernandez Guillermet, A.; Sade, M.
1999-01-01
Very recent, accurate dilatometric measurements of the fcc hcp martensitic transformation (MT) temperatures are used to develop a new thermodynamic description of the fcc and hcp phases in the Fe-Mn-Si system, based on phenomenological models for the Gibbs energy function. The composition dependence of the driving forces for the fcc→hcp and the hcp→fcc MTs is established. Detailed calculations of the MT temperatures are reported, which are used to investigate the systematic effects of Si additions upon the MT temperatures of Fe-Mn alloys. A critical comparison with one of the most recent thermodynamic analyses of the Fe-Mn-Si system, which is due to Forsberg and Agren, is also presented. (orig.)
Energy Resources Consumption Minimization in Housing Construction
Directory of Open Access Journals (Sweden)
Balastov Alexey
2017-01-01
Full Text Available The article deals with the energy savings analysis during operation of buildings, provides the heat balance of residential premises, considers options for energy-efficient solutions for hot water supply systems in buildings. As technical facilities that allow the use of secondary heat sources and solar energy, there are also considered the systems with heat recovery of “gray” wastewater, heat pumps, solar collectors and photoelectric converters.
Unused energy sources inducing minimal pollution
Energy Technology Data Exchange (ETDEWEB)
Voss, A [Inst. fur Reaktorentwicklung, Kernforschungsanlage Julich GmbH, German Federal Republic
1974-01-01
The contribution of hydroelectricity to the growing worldwide energy demand is not expected to exceed 6%. As the largest amount of hydroelectric potential is located in developing nations, it will find its greatest development outside the currently industrialized sphere. The potential of 60 GW ascribed to tidal and geothermal energy is a negligible quantity. Solar energy represents an essentially inexhaustible source, but technological problems will preclude any major contribution from it during this century. The environmental problems caused by these 'new' energy sources are different from those engendered by fossil and nuclear power plants, but they are not negligible. It is irresponsible and misleading to describe them as pollution-free.
International Nuclear Information System (INIS)
Li, H.Q.; Yang, Y.S.; Tong, W.H.; Wang, Z.Y.
2007-01-01
With the effects of electronic structure and atomic size being introduced, the mixing enthalpy as well as the Gibbs energy of the ternary Zr-Al-Cu, Ni-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated based on quasiregular solution model. The computed results agree well with the experimental data. The sequence of Gibbs energies of different systems is: G Zr-Al-Ni-Cu Zr-Al-Ni Zr-Al-Cu Cu-Al-Ni . To Zr-Al-Cu, Ni-Al-Cu and Zr-Ni-Al, the lowest Gibbs energy locates in the composition range of X Zr 0.39-0.61, X Al = 0.38-0.61; X Ni = 0.39-0.61, X Al = 0.38-0.60 and X Zr = 0.32-0.67, X Al = 0.32-0.66, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the lowest Gibbs energy is obtained in the region of X Al = 0.63-0.80, X Ni = 0.14-0.24
Low energy implications of minimal superstring unification
International Nuclear Information System (INIS)
Khalil, S.; Vissani, F.; Masiero, A.
1995-11-01
We study the phenomenological implications of effective supergravities based on string vacua with spontaneously broken N =1 supersymmetry by dilation and moduli F-terms. We further require Minimal String Unification, namely that large string threshold corrections ensure the correct unification of the gauge couplings at the grand unification scale. The whole supersymmetric mass spectrum turns out to be determined in terms of only two independent parameters, the dilaton-moduli mixing angle and the gravitino mass. In particular we discuss the region of the parameter space where at least one superpartner is ''visible'' at LEPII. We find that the most likely candidates are the scalar partner of the right-handed electron and the lightest chargino, with interesting correlations between their masses and with the mass of the lightest higgs. We show how discovering SUSY particles at LEPII might rather sharply discriminate between scenarios with pure dilaton SUSY breaking and mixed dilaton-moduli breaking. (author). 10 refs, 7 figs
International Nuclear Information System (INIS)
Xu, H.
1999-01-01
In this letter, the Sverjensky-Molling equation derived from a linear free energy relationship is used to calculate the Gibbs free energies of formation of zirconolite crystalline phases (MZrTi 2 O 7 and MHfTi 2 O 7 ) from the known thermodynamic properties of the corresponding aqueous divalent cations (M 2+ ). Sverjensky-Molling equation is expressed as ΔG 0 f,M v X =a M v X ΔG 0 n,M 2+ +b M v X +β M v X r M 2+ , where the coefficients a M v X , b M v X , and β M v X characterize a particular structural family of M v X, r M 2+ is the ionic radius of M 2+ cation, ΔG f,M v X 0 is the standard Gibbs free energy of formation of M v X, and ΔG 0 n,M 2+ is the standard non-solvation energy of cation M 2+ . This relationship can be used to predict the Gibbs free energies of formation of various fictive phases (such as BaZrTi 2 O 7 , SrZrTi 2 O 7 , PbZrTi 2 O 7 , etc.) that may form solid solution with CaZrTi 2 O 7 in actual Synroc-based nuclear waste forms. Based on obtained linear free energy relationships, it is predicted that large cations (e.g., Ba and Ra) prefer to be in perovskite structure, and small cations (e.g., Ca, Zn, and Cd) prefer to be in zirconolite structure. (orig.)
Dimensionality of Local Minimizers of the Interaction Energy
Balagué, D.
2013-05-22
In this work we consider local minimizers (in the topology of transport distances) of the interaction energy associated with a repulsive-attractive potential. We show how the dimensionality of the support of local minimizers is related to the repulsive strength of the potential at the origin. © 2013 Springer-Verlag Berlin Heidelberg.
Dimensionality of Local Minimizers of the Interaction Energy
Balagué , D.; Carrillo, J. A.; Laurent, T.; Raoul, G.
2013-01-01
In this work we consider local minimizers (in the topology of transport distances) of the interaction energy associated with a repulsive-attractive potential. We show how the dimensionality of the support of local minimizers is related to the repulsive strength of the potential at the origin. © 2013 Springer-Verlag Berlin Heidelberg.
International Nuclear Information System (INIS)
Vecchio, Stefano; Brunetti, Bruno
2009-01-01
The vapor pressures of the solid and liquid 2,4- and 3,4-dinitrobenzoic acids were determined by torsion-effusion and thermogravimetry under both isothermal and non-isothermal conditions, respectively. From the temperature dependence of vapor pressure derived by the experimental torsion-effusion and thermogravimetry data the molar enthalpies of sublimation Δ cr g H m 0 ( ) and vaporization Δ l g H m 0 ( ) were determined, respectively, at the middle of the respective temperature intervals. The melting temperatures and the molar enthalpies of fusion of these compounds were measured by d.s.c. Finally, the results obtained by all the methods proposed were corrected at the reference temperature of 298.15 K using the estimated heat capacity differences between gas and liquid for vaporization experiments and the estimated heat capacity differences between gas and solid for sublimation experiments. Therefore, the averages of the standard (p o = 0.1 MPa) molar enthalpies, entropies and Gibbs free energies of sublimation at 298.15 K, have been derived.
Obendorf, Hartmut
2009-01-01
The notion of Minimalism is proposed as a theoretical tool supporting a more differentiated understanding of reduction and thus forms a standpoint that allows definition of aspects of simplicity. This book traces the development of minimalism, defines the four types of minimalism in interaction design, and looks at how to apply it.
Hoelder continuity of energy minimizer maps between Riemannian polyhedra
International Nuclear Information System (INIS)
Bouziane, Taoufik
2004-10-01
The goal of the present paper is to establish some kind of regularity of an energy minimizer map between Riemannian polyhedra. More precisely, we will show the Hoelder continuity of local energy minimizers between Riemannian polyhedra with the target spaces without focal points. With this new result, we also complete our existence theorem obtained elsewhere, and consequently we generalize completely, to the case of target polyhedra without focal points (which is a weaker geometric condition than the nonpositivity of the curvature), the Eells-Fuglede's existence and regularity theorem which is the new version of the famous Eells-Sampson's theorem. (author)
Ahmad, Enas M.
2013-01-01
, they are significantly adding an overhead on the limited energy of the battery. This thesis aims at enhancing the energy efficiency of modern smartphones and increasing their battery life by minimizing the energy consumption of smartphones Graphical Processing Unit (GPU
An existence result of energy minimizer maps between Riemannian polyhedra
International Nuclear Information System (INIS)
Bouziane, T.
2004-06-01
In this paper, we prove the existence of energy minimizers in each free homotopy class of maps between polyhedra with target space without focal points. Our proof involves a careful study of some geometric properties of Riemannian polyhedra without focal points. Among other things, we show that on the relevant polyhedra, there exists a convex supporting function. (author)
Minimal Self-Models and the Free Energy Principle
Directory of Open Access Journals (Sweden)
Jakub eLimanowski
2013-09-01
Full Text Available The term "minimal phenomenal selfhood" describes the basic, pre-reflective experience of being a self (Blanke & Metzinger, 2009. Theoretical accounts of the minimal self have long recognized the importance and the ambivalence of the body as both part of the physical world, and the enabling condition for being in this world (Gallagher, 2005; Grafton, 2009. A recent account of minimal phenomenal selfhood (MPS, Metzinger, 2004a centers on the consideration that minimal selfhood emerges as the result of basic self-modeling mechanisms, thereby being founded on pre-reflective bodily processes. The free energy principle (FEP, Friston, 2010 is a novel unified theory of cortical function that builds upon the imperative that self-organizing systems entail hierarchical generative models of the causes of their sensory input, which are optimized by minimizing free energy as an approximation of the log-likelihood of the model. The implementation of the FEP via predictive coding mechanisms and in particular the active inference principle emphasizes the role of embodiment for predictive self-modeling, which has been appreciated in recent publications. In this review, we provide an overview of these conceptions and illustrate thereby the potential power of the FEP in explaining the mechanisms underlying minimal selfhood and its key constituents, multisensory integration, interoception, agency, perspective, and the experience of mineness. We conclude that the conceptualization of MPS can be well mapped onto a hierarchical generative model furnished by the free energy principle and may constitute the basis for higher-level, cognitive forms of self-referral, as well as the understanding of other minds.
Efficient modified Jacobi relaxation for minimizing the energy functional
International Nuclear Information System (INIS)
Park, C.H.; Lee, I.; Chang, K.J.
1993-01-01
We present an efficient scheme of diagonalizing large Hamiltonian matrices in a self-consistent manner. In the framework of the preconditioned conjugate gradient minimization of the energy functional, we replace the modified Jacobi relaxation for preconditioning and use for band-by-band minimization the restricted-block Davidson algorithm, in which only the previous wave functions and the relaxation vectors are included additionally for subspace diagonalization. Our scheme is found to be comparable with the preconditioned conjugate gradient method for both large ordered and disordered Si systems, while it is more rapidly converged for systems with transition-metal elements
Minimization of local impact of energy systems through exergy analysis
International Nuclear Information System (INIS)
Cassetti, Gabriele; Colombo, Emanuela
2013-01-01
Highlights: • The model proposed aims at minimizing local impact of energy systems. • The model is meant to minimize the impact starting from system thermodynamics. • The formulation combines exergy analysis and quantitative risk analysis. • The approach of the model is dual to Thermoeconomics. - Abstract: For the acceptability of energy systems, environmental impacts are becoming more and more important. One primary way for reducing impacts related to processes is by improving efficiency of plants. A key instrument currently used to verify such improvements is exergy analysis, extended to include also the environmental externalities generated by systems. Through exergy-based analyses, it is possible indeed to evaluate the overall amount of resources consumed along all the phases of the life cycle of a system, from construction to dismantling. However, resource consumption is a dimension of the impact of a system at global level, while it may not be considered a measure of its local impact. In the paper a complementary approach named Combined Risk and Exergy Analysis (CRExA) to assess impacts from major accidents in energy systems is proposed, based on the combination of classical exergy analysis and quantitative risk analysis (QRA). Impacts considered are focused on effects on human health. The approach leads to the identification of solutions to minimize damages of major accidents by acting on the energy system design
Minimizing Energy Spread In The REX/HIE-ISOLDE Linac
Yucemoz, Mert
2017-01-01
This report tries to minimize the energy spread of the beam at the end of the REX-HIE-ISOLDE Linac using the last RF cavity as a buncher. Beams with very low energy spread are often required by the users of the facility In addition, one of the main reason to have minimum energy spread in longitudinal phase space is that higher beam energy spread translates in to a position spread after interacting with target. This causes an overlap in the position of different particles that makes it difficult to distinguish them. Hence, in order to find the operation settings for minimum energy spread at the end of the REX-HIE-ISOLDE linac and to inspect the ongoing physics, several functions on Matlab were created that runs beam dynamics program called “TRACKV39” that provides some graphs and values as a result for analysis.
Cooperative relay-based multicasting for energy and delay minimization
Atat, Rachad
2012-08-01
Relay-based multicasting for the purpose of cooperative content distribution is studied. Optimized relay selection is performed with the objective of minimizing the energy consumption or the content distribution delay within a cluster of cooperating mobiles. Two schemes are investigated. The first consists of the BS sending the data only to the relay, and the second scheme considers the scenario of threshold-based multicasting by the BS, where a relay is selected to transmit the data to the mobiles that were not able to receive the multicast data. Both schemes show significant superiority compared to the non-cooperative scenarios, in terms of energy consumption and delay reduction. © 2012 IEEE.
Rigid Body Energy Minimization on Manifolds for Molecular Docking.
Mirzaei, Hanieh; Beglov, Dmitri; Paschalidis, Ioannis Ch; Vajda, Sandor; Vakili, Pirooz; Kozakov, Dima
2012-11-13
Virtually all docking methods include some local continuous minimization of an energy/scoring function in order to remove steric clashes and obtain more reliable energy values. In this paper, we describe an efficient rigid-body optimization algorithm that, compared to the most widely used algorithms, converges approximately an order of magnitude faster to conformations with equal or slightly lower energy. The space of rigid body transformations is a nonlinear manifold, namely, a space which locally resembles a Euclidean space. We use a canonical parametrization of the manifold, called the exponential parametrization, to map the Euclidean tangent space of the manifold onto the manifold itself. Thus, we locally transform the rigid body optimization to an optimization over a Euclidean space where basic optimization algorithms are applicable. Compared to commonly used methods, this formulation substantially reduces the dimension of the search space. As a result, it requires far fewer costly function and gradient evaluations and leads to a more efficient algorithm. We have selected the LBFGS quasi-Newton method for local optimization since it uses only gradient information to obtain second order information about the energy function and avoids the far more costly direct Hessian evaluations. Two applications, one in protein-protein docking, and the other in protein-small molecular interactions, as part of macromolecular docking protocols are presented. The code is available to the community under open source license, and with minimal effort can be incorporated into any molecular modeling package.
A strategy to find minimal energy nanocluster structures.
Rogan, José; Varas, Alejandro; Valdivia, Juan Alejandro; Kiwi, Miguel
2013-11-05
An unbiased strategy to search for the global and local minimal energy structures of free standing nanoclusters is presented. Our objectives are twofold: to find a diverse set of low lying local minima, as well as the global minimum. To do so, we use massively the fast inertial relaxation engine algorithm as an efficient local minimizer. This procedure turns out to be quite efficient to reach the global minimum, and also most of the local minima. We test the method with the Lennard-Jones (LJ) potential, for which an abundant literature does exist, and obtain novel results, which include a new local minimum for LJ13 , 10 new local minima for LJ14 , and thousands of new local minima for 15≤N≤65. Insights on how to choose the initial configurations, analyzing the effectiveness of the method in reaching low-energy structures, including the global minimum, are developed as a function of the number of atoms of the cluster. Also, a novel characterization of the potential energy surface, analyzing properties of the local minima basins, is provided. The procedure constitutes a promising tool to generate a diverse set of cluster conformations, both two- and three-dimensional, that can be used as an input for refinement by means of ab initio methods. Copyright © 2013 Wiley Periodicals, Inc.
Minimizing the Energy Consumption in Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Mohammed Saad Talib
2017-12-01
Full Text Available Energy in Wireless Sensor networks (WSNs represents an essential factor in designing, controlling and operating the sensor networks. Minimizing the consumed energy in WSNs application is a crucial issue for the network effectiveness and efficiency in terms of lifetime, cost and operation. Number of algorithms and protocols were proposed and implemented to decrease the energy consumption. WSNs operate with battery powered sensors. Sensors batteries have not easily rechargeable even though having restricted power. Frequently the network failure occurs due to the sensors energy insufficiency. MAC protocols in WSNs achieved low duty-cycle by employing periodic sleep and wakeup. Predictive Wakeup MAC (PW-MAC protocol was made use of the asynchronous duty cycling. It reduces the consumption of the node energy by allowing the senders to predict the receiver′s wakeup times. The WSN must be applied in an efficient manner to utilize the sensor nodes and their energy to ensure efficient network throughput. Prediction of the WSN lifetime previously to its installation represents a significant concern. To ensure energy efficiency the sensors duty cycles must be adjusted appropriately to meet the network traffic demands. The energy consumed in each node due to its switching between the active and the idle states were also estimated. The sensors are assumed to be randomly deployed. This paper aims to improve the randomly deployed network lifetime by scheduling the effects of transmission, reception and sleep states on the sensor node energy consumption. Results for these states with many performance metrics were also studied and discussed
International Nuclear Information System (INIS)
Sandstroem, Malin Hannah; Bostroem, Dan; Rosen, Erik
2006-01-01
The equilibrium reactions: 3Ca 2 P 2 O 7 (s)+6Ni(s)-bar 2Ca 3 (PO 4 ) 2 (s)+2Ni 3 P(s)+52O 2 (g) and 2Ca(PO 3 ) 2 (s)+6Ni(s)-bar Ca 2 P 2 O 7 (s)+2Ni 3 P(s)+52O 2 (g) were studied in the temperature range 890K to 1140K. The oxygen equilibrium pressures were determined using galvanic cells incorporating yttria stabilized zirconia as solid electrolyte. From the measured data and using the literature values of standard Gibbs free energy of formation for Ca 3 (PO 4 ) 2 and Ni 3 P, the following relationship of the standard Gibbs free energy of formation for Ca 2 P 2 O 7 and Ca(PO 3 ) 2 were calculated:Δ f G o (Ca 2 P 2 O 7 )+/-11/(kJ.mol -1 )=-3475.9+1.5441(T/K)-0.1051(T/K).ln(T/K)andΔ f G o (Ca(PO 3 ) 2 )+/-12/(kJ.mol -1 )=-3334.8+6.1561(T/K)-0.6950(T/K).ln(T/K)
Energy minimization in medical image analysis: Methodologies and applications.
Zhao, Feng; Xie, Xianghua
2016-02-01
Energy minimization is of particular interest in medical image analysis. In the past two decades, a variety of optimization schemes have been developed. In this paper, we present a comprehensive survey of the state-of-the-art optimization approaches. These algorithms are mainly classified into two categories: continuous method and discrete method. The former includes Newton-Raphson method, gradient descent method, conjugate gradient method, proximal gradient method, coordinate descent method, and genetic algorithm-based method, while the latter covers graph cuts method, belief propagation method, tree-reweighted message passing method, linear programming method, maximum margin learning method, simulated annealing method, and iterated conditional modes method. We also discuss the minimal surface method, primal-dual method, and the multi-objective optimization method. In addition, we review several comparative studies that evaluate the performance of different minimization techniques in terms of accuracy, efficiency, or complexity. These optimization techniques are widely used in many medical applications, for example, image segmentation, registration, reconstruction, motion tracking, and compressed sensing. We thus give an overview on those applications as well. Copyright © 2015 John Wiley & Sons, Ltd.
Outage Probability Minimization for Energy Harvesting Cognitive Radio Sensor Networks
Directory of Open Access Journals (Sweden)
Fan Zhang
2017-01-01
Full Text Available The incorporation of cognitive radio (CR capability in wireless sensor networks yields a promising network paradigm known as CR sensor networks (CRSNs, which is able to provide spectrum efficient data communication. However, due to the high energy consumption results from spectrum sensing, as well as subsequent data transmission, the energy supply for the conventional sensor nodes powered by batteries is regarded as a severe bottleneck for sustainable operation. The energy harvesting technique, which gathers energy from the ambient environment, is regarded as a promising solution to perpetually power-up energy-limited devices with a continual source of energy. Therefore, applying the energy harvesting (EH technique in CRSNs is able to facilitate the self-sustainability of the energy-limited sensors. The primary concern of this study is to design sensing-transmission policies to minimize the long-term outage probability of EH-powered CR sensor nodes. We formulate this problem as an infinite-horizon discounted Markov decision process and propose an ϵ-optimal sensing-transmission (ST policy through using the value iteration algorithm. ϵ is the error bound between the ST policy and the optimal policy, which can be pre-defined according to the actual need. Moreover, for a special case that the signal-to-noise (SNR power ratio is sufficiently high, we present an efficient transmission (ET policy and prove that the ET policy achieves the same performance with the ST policy. Finally, extensive simulations are conducted to evaluate the performance of the proposed policies and the impaction of various network parameters.
Energy Cost Minimization in Heterogeneous Cellular Networks with Hybrid Energy Supplies
Directory of Open Access Journals (Sweden)
Bang Wang
2016-01-01
Full Text Available The ever increasing data demand has led to the significant increase of energy consumption in cellular mobile networks. Recent advancements in heterogeneous cellular networks and green energy supplied base stations provide promising solutions for cellular communications industry. In this article, we first review the motivations and challenges as well as approaches to address the energy cost minimization problem for such green heterogeneous networks. Owing to the diversities of mobile traffic and renewable energy, the energy cost minimization problem involves both temporal and spatial optimization of resource allocation. We next present a new solution to illustrate how to combine the optimization of the temporal green energy allocation and spatial mobile traffic distribution. The whole optimization problem is decomposed into four subproblems, and correspondingly our proposed solution is divided into four parts: energy consumption estimation, green energy allocation, user association, and green energy reallocation. Simulation results demonstrate that our proposed algorithm can significantly reduce the total energy cost.
Interactive seismic interpretation with piecewise global energy minimization
Hollt, Thomas
2011-03-01
Increasing demands in world-wide energy consumption and oil depletion of large reservoirs have resulted in the need for exploring smaller and more complex oil reservoirs. Planning of the reservoir valorization usually starts with creating a model of the subsurface structures, including seismic faults and horizons. However, seismic interpretation and horizon tracing is a difficult and error-prone task, often resulting in hours of work needing to be manually repeated. In this paper, we propose a novel, interactive workflow for horizon interpretation based on well positions, which include additional geological and geophysical data captured by actual drillings. Instead of interpreting the volume slice-by-slice in 2D, we propose 3D seismic interpretation based on well positions. We introduce a combination of 2D and 3D minimal cost path and minimal cost surface tracing for extracting horizons with very little user input. By processing the volume based on well positions rather than slice-based, we are able to create a piecewise optimal horizon surface at interactive rates. We have integrated our system into a visual analysis platform which supports multiple linked views for fast verification, exploration and analysis of the extracted horizons. The system is currently being evaluated by our collaborating domain experts. © 2011 IEEE.
Interactive seismic interpretation with piecewise global energy minimization
Hollt, Thomas; Beyer, Johanna; Gschwantner, Fritz M.; Muigg, Philipp; Doleisch, Helmut; Heinemann, Gabor F.; Hadwiger, Markus
2011-01-01
Increasing demands in world-wide energy consumption and oil depletion of large reservoirs have resulted in the need for exploring smaller and more complex oil reservoirs. Planning of the reservoir valorization usually starts with creating a model of the subsurface structures, including seismic faults and horizons. However, seismic interpretation and horizon tracing is a difficult and error-prone task, often resulting in hours of work needing to be manually repeated. In this paper, we propose a novel, interactive workflow for horizon interpretation based on well positions, which include additional geological and geophysical data captured by actual drillings. Instead of interpreting the volume slice-by-slice in 2D, we propose 3D seismic interpretation based on well positions. We introduce a combination of 2D and 3D minimal cost path and minimal cost surface tracing for extracting horizons with very little user input. By processing the volume based on well positions rather than slice-based, we are able to create a piecewise optimal horizon surface at interactive rates. We have integrated our system into a visual analysis platform which supports multiple linked views for fast verification, exploration and analysis of the extracted horizons. The system is currently being evaluated by our collaborating domain experts. © 2011 IEEE.
Free-energy minimization and the dark-room problem.
Friston, Karl; Thornton, Christopher; Clark, Andy
2012-01-01
Recent years have seen the emergence of an important new fundamental theory of brain function. This theory brings information-theoretic, Bayesian, neuroscientific, and machine learning approaches into a single framework whose overarching principle is the minimization of surprise (or, equivalently, the maximization of expectation). The most comprehensive such treatment is the "free-energy minimization" formulation due to Karl Friston (see e.g., Friston and Stephan, 2007; Friston, 2010a,b - see also Fiorillo, 2010; Thornton, 2010). A recurrent puzzle raised by critics of these models is that biological systems do not seem to avoid surprises. We do not simply seek a dark, unchanging chamber, and stay there. This is the "Dark-Room Problem." Here, we describe the problem and further unpack the issues to which it speaks. Using the same format as the prolog of Eddington's Space, Time, and Gravitation (Eddington, 1920) we present our discussion as a conversation between: an information theorist (Thornton), a physicist (Friston), and a philosopher (Clark).
Directory of Open Access Journals (Sweden)
Thanh Tung Ha
2018-03-01
Full Text Available The structural and optimal operation of an Energy Hub (EH has a tremendous influence on the hub’s performance and reliability. This paper envisions an innovative methodology that prominently increases the synergy between structural and operational optimization and targets system cost affordability. The generalized energy system structure is presented theoretically with all selective hub sub-modules, including electric heater (EHe and solar sources block sub-modules. To minimize energy usage cost, an energy hub is proposed that consists of 12 kinds of elements (i.e., energy resources, conversion, and storage functions and is modeled mathematically in a General Algebraic Modeling System (GAMS, which indicates the optimal hub structure’s corresponding elements with binary variables (0, 1. Simulation results contrast with 144 various scenarios established in all 144 categories of hub structures, in which for each scenario the corresponding optimal operation cost is previously calculated. These case studies demonstrate the effectiveness of the suggested model and methodology. Finally, avenues for future research are also prospected.
Quantum Gibbs Samplers: The Commuting Case
Kastoryano, Michael J.; Brandão, Fernando G. S. L.
2016-06-01
We analyze the problem of preparing quantum Gibbs states of lattice spin Hamiltonians with local and commuting terms on a quantum computer and in nature. Our central result is an equivalence between the behavior of correlations in the Gibbs state and the mixing time of the semigroup which drives the system to thermal equilibrium (the Gibbs sampler). We introduce a framework for analyzing the correlation and mixing properties of quantum Gibbs states and quantum Gibbs samplers, which is rooted in the theory of non-commutative {mathbb{L}_p} spaces. We consider two distinct classes of Gibbs samplers, one of them being the well-studied Davies generator modelling the dynamics of a system due to weak-coupling with a large Markovian environment. We show that their spectral gap is independent of system size if, and only if, a certain strong form of clustering of correlations holds in the Gibbs state. Therefore every Gibbs state of a commuting Hamiltonian that satisfies clustering of correlations in this strong sense can be prepared efficiently on a quantum computer. As concrete applications of our formalism, we show that for every one-dimensional lattice system, or for systems in lattices of any dimension at temperatures above a certain threshold, the Gibbs samplers of commuting Hamiltonians are always gapped, giving an efficient way of preparing the associated Gibbs states on a quantum computer.
Energy minimization strategies and renewable energy utilization for desalination: a review.
Subramani, Arun; Badruzzaman, Mohammad; Oppenheimer, Joan; Jacangelo, Joseph G
2011-02-01
Energy is a significant cost in the economics of desalinating waters, but water scarcity is driving the rapid expansion in global installed capacity of desalination facilities. Conventional fossil fuels have been utilized as their main energy source, but recent concerns over greenhouse gas (GHG) emissions have promoted global development and implementation of energy minimization strategies and cleaner energy supplies. In this paper, a comprehensive review of energy minimization strategies for membrane-based desalination processes and utilization of lower GHG emission renewable energy resources is presented. The review covers the utilization of energy efficient design, high efficiency pumping, energy recovery devices, advanced membrane materials (nanocomposite, nanotube, and biomimetic), innovative technologies (forward osmosis, ion concentration polarization, and capacitive deionization), and renewable energy resources (solar, wind, and geothermal). Utilization of energy efficient design combined with high efficiency pumping and energy recovery devices have proven effective in full-scale applications. Integration of advanced membrane materials and innovative technologies for desalination show promise but lack long-term operational data. Implementation of renewable energy resources depends upon geography-specific abundance, a feasible means of handling renewable energy power intermittency, and solving technological and economic scale-up and permitting issues. Copyright © 2011 Elsevier Ltd. All rights reserved.
Geometric and Texture Inpainting by Gibbs Sampling
DEFF Research Database (Denmark)
Gustafsson, David Karl John; Pedersen, Kim Steenstrup; Nielsen, Mads
2007-01-01
. In this paper we use the well-known FRAME (Filters, Random Fields and Maximum Entropy) for inpainting. We introduce a temperature term in the learned FRAME Gibbs distribution. By sampling using different temperature in the FRAME Gibbs distribution, different contents of the image are reconstructed. We propose...... a two step method for inpainting using FRAME. First the geometric structure of the image is reconstructed by sampling from a cooled Gibbs distribution, then the stochastic component is reconstructed by sample froma heated Gibbs distribution. Both steps in the reconstruction process are necessary...
Zhang, Jun; Gu, Zhenghui; Yu, Zhu Liang; Li, Yuanqing
2015-03-01
Low energy consumption is crucial for body area networks (BANs). In BAN-enabled ECG monitoring, the continuous monitoring entails the need of the sensor nodes to transmit a huge data to the sink node, which leads to excessive energy consumption. To reduce airtime over energy-hungry wireless links, this paper presents an energy-efficient compressed sensing (CS)-based approach for on-node ECG compression. At first, an algorithm called minimal mutual coherence pursuit is proposed to construct sparse binary measurement matrices, which can be used to encode the ECG signals with superior performance and extremely low complexity. Second, in order to minimize the data rate required for faithful reconstruction, a weighted ℓ1 minimization model is derived by exploring the multisource prior knowledge in wavelet domain. Experimental results on MIT-BIH arrhythmia database reveals that the proposed approach can obtain higher compression ratio than the state-of-the-art CS-based methods. Together with its low encoding complexity, our approach can achieve significant energy saving in both encoding process and wireless transmission.
Ahmad, Enas M.
2013-05-15
Modern smartphones are being designed with increasing processing power, memory capacity, network communication, and graphics performance. Although all of these features are enriching and expanding the experience of a smartphone user, they are significantly adding an overhead on the limited energy of the battery. This thesis aims at enhancing the energy efficiency of modern smartphones and increasing their battery life by minimizing the energy consumption of smartphones Graphical Processing Unit (GPU). Smartphone operating systems are becoming fully hardware-accelerated, which implies relying on the GPU power for rendering all application graphics. In addition, the GPUs installed in smartphones are becoming more and more powerful by the day. This raises an energy consumption concern. We present a novel implementation of GPU Scaling Governors, a Dynamic Voltage and Frequency Scaling (DVFS) scheme implemented in the Android kernel to dynamically scale the GPU. The scheme includes four main governors: Performance, Powersave, Ondmand, and Conservative. Unlike previous studies which looked into the power efficiency of mobile GPUs only through simulation and power estimations, we have implemented our approach on a real modern smartphone GPU, and acquired actual energy measurements using an external power monitor. Our results show that the energy consumption of smartphones can be reduced up to 15% using the Conservative governor in 2D rendering mode, and up to 9% in 3D rendering mode, with minimal effect on the performance.
Minimizing energy consumption of accelerators and storage ring facilities
International Nuclear Information System (INIS)
The discussion of energy usage falls naturally into three parts. The first is a review of what the problem is, the second is a description of steps that can be taken to conserve energy at existing facilities, and the third is a review of the implications of energy consumption on future facilities
International Nuclear Information System (INIS)
Yang Chao; Meza, Juan C.; Wang Linwang
2006-01-01
A new direct constrained optimization algorithm for minimizing the Kohn-Sham (KS) total energy functional is presented in this paper. The key ingredients of this algorithm involve projecting the total energy functional into a sequence of subspaces of small dimensions and seeking the minimizer of total energy functional within each subspace. The minimizer of a subspace energy functional not only provides a search direction along which the KS total energy functional decreases but also gives an optimal 'step-length' to move along this search direction. Numerical examples are provided to demonstrate that this new direct constrained optimization algorithm can be more efficient than the self-consistent field (SCF) iteration
Free energy minimization and information gain: The devil is in the details
Kwisthout, J.H.P.; Rooij, I.J.E.I. van
2015-01-01
Contrary to Friston's previous work, this paper describes free energy minimization using categorical probability distributions over discrete states. This alternative mathematical framework exposes a fundamental, yet unnoticed challenge for the free energy principle. When considering discrete state
International Nuclear Information System (INIS)
Fazary, Ahmed E.; Alshihri, Ayed S.; Alfaifi, Mohammad Y.; Saleh, Kamel A.; Elbehairi, Serag Eldin I.; Fawy, Khaled F.; Abd-Rabboh, Hisham S.M.
2016-01-01
Highlights: • The experimental thermodynamic equilibrium and stability constants of vanadium and platinum complexes involving naringin, ferulic acid, p-coumaric acid, caffeic acid, vanillic acid, sinapic acid, and gallic acid were determined. • The theoretical calculations of the free energy changes associated with the ligand protonation, and metal ion–ligand complex formation equilibria using density function theory calculations, providing a complete picture of the microscopic equilibria of the studied complex systems. - Abstract: The Experimental thermodynamic equilibrium (pK_a values) and stability (log β) constants of vanadium and platinum binary and mixed ligand complexes involving naringenin, ferulic acid, p-coumaric acid, caffeic acid, vanillic acid, sinapic acid, and gallic acid were determined at 310.15 K in 0.16 mol·dm"−"3 KCl aqueous solutions using pH-potentiometric technique and by means of two estimation models (HYPERQUAD 2008 and Bjerrum–Calvin). The theoretical calculations of overall protonation and stability constants of the metal complex species in solution were predicted as the free energy change associated with the ligand protonation, and metal ion–ligand complex formation equilibria (species solvation/de-solvation) using ab initio and density function theory (DFT) calculations. The usage of the experimental potentiometry technique and theoretical predictions provides a complete picture of the microscopic equilibria of the studied systems (vanadium/platinum–naringenin–phenolic acid). Specifically, this theoretically DFT predications would be useful to determine the most real protonation constants of the studied bioligands in which the binding sites changes due to the ligand protonation/deprotonation equilibria. Also, the complexing capacities of vanadium and platinum towards naringenin, ferulic acid, p-coumaric acid, caffeic acid, vanillic acid, sinapic acid, and gallic acid in solutions were evaluated and discussed. From the
Gibbs' theorem for open systems with incomplete statistics
International Nuclear Information System (INIS)
Bagci, G.B.
2009-01-01
Gibbs' theorem, which is originally intended for canonical ensembles with complete statistics has been generalized to open systems with incomplete statistics. As a result of this generalization, it is shown that the stationary equilibrium distribution of inverse power law form associated with the incomplete statistics has maximum entropy even for open systems with energy or matter influx. The renormalized entropy definition given in this paper can also serve as a measure of self-organization in open systems described by incomplete statistics.
Extension of Gibbs-Duhem equation including influences of external fields
Guangze, Han; Jianjia, Meng
2018-03-01
Gibbs-Duhem equation is one of the fundamental equations in thermodynamics, which describes the relation among changes in temperature, pressure and chemical potential. Thermodynamic system can be affected by external field, and this effect should be revealed by thermodynamic equations. Based on energy postulate and the first law of thermodynamics, the differential equation of internal energy is extended to include the properties of external fields. Then, with homogeneous function theorem and a redefinition of Gibbs energy, a generalized Gibbs-Duhem equation with influences of external fields is derived. As a demonstration of the application of this generalized equation, the influences of temperature and external electric field on surface tension, surface adsorption controlled by external electric field, and the derivation of a generalized chemical potential expression are discussed, which show that the extended Gibbs-Duhem equation developed in this paper is capable to capture the influences of external fields on a thermodynamic system.
Discretized energy minimization in a wave guide with point sources
Propst, G.
1994-01-01
An anti-noise problem on a finite time interval is solved by minimization of a quadratic functional on the Hilbert space of square integrable controls. To this end, the one-dimensional wave equation with point sources and pointwise reflecting boundary conditions is decomposed into a system for the two propagating components of waves. Wellposedness of this system is proved for a class of data that includes piecewise linear initial conditions and piecewise constant forcing functions. It is shown that for such data the optimal piecewise constant control is the solution of a sparse linear system. Methods for its computational treatment are presented as well as examples of their applicability. The convergence of discrete approximations to the general optimization problem is demonstrated by finite element methods.
Charge and energy minimization in electrical/magnetic stimulation of nervous tissue.
Jezernik, Saso; Sinkjaer, Thomas; Morari, Manfred
2010-08-01
In this work we address the problem of stimulating nervous tissue with the minimal necessary energy at reduced/minimal charge. Charge minimization is related to a valid safety concern (avoidance and reduction of stimulation-induced tissue and electrode damage). Energy minimization plays a role in battery-driven electrical or magnetic stimulation systems (increased lifetime, repetition rates, reduction of power requirements, thermal management). Extensive new theoretical results are derived by employing an optimal control theory framework. These results include derivation of the optimal electrical stimulation waveform for a mixed energy/charge minimization problem, derivation of the charge-balanced energy-minimal electrical stimulation waveform, solutions of a pure charge minimization problem with and without a constraint on the stimulation amplitude, and derivation of the energy-minimal magnetic stimulation waveform. Depending on the set stimulus pulse duration, energy and charge reductions of up to 80% are deemed possible. Results are verified in simulations with an active, mammalian-like nerve fiber model.
Probing gravitational non-minimal coupling with dark energy surveys
International Nuclear Information System (INIS)
Geng, Chao-Qiang; Lee, Chung-Chi; Wu, Yi-Peng
2017-01-01
We investigate observational constraints on a specific one-parameter extension to the minimal quintessence model, where the quintessence field acquires a quadratic coupling to the scalar curvature through a coupling constant ξ. The value of ξ is highly suppressed in typical tracker models if the late-time cosmic acceleration is driven at some field values near the Planck scale. We test ξ in a second class of models in which the field value today becomes a free model parameter. We use the combined data from type-Ia supernovae, cosmic microwave background, baryon acoustic oscillations and matter power spectrum, to weak lensing measurements and find a best-fit value ξ > 0.289 where ξ = 0 is excluded outside the 95% confidence region. The effective gravitational constant G_e_f_f subject to the hint of a non-zero ξ is constrained to -0.003 < 1 - G_e_f_f/G < 0.033 at the same confidence level on cosmological scales, and it can be narrowed down to 1 - G_e_f_f/G < 2.2 x 10"-"5 when combining with Solar System tests. (orig.)
Probing gravitational non-minimal coupling with dark energy surveys
Energy Technology Data Exchange (ETDEWEB)
Geng, Chao-Qiang [Chongqing University of Posts and Telecommunications, Chongqing (China); National Tsing Hua University, Department of Physics, Hsinchu (China); National Center for Theoretical Sciences, Hsinchu (China); Lee, Chung-Chi [National Center for Theoretical Sciences, Hsinchu (China); Wu, Yi-Peng [Academia Sinica, Institute of Physics, Taipei (China)
2017-03-15
We investigate observational constraints on a specific one-parameter extension to the minimal quintessence model, where the quintessence field acquires a quadratic coupling to the scalar curvature through a coupling constant ξ. The value of ξ is highly suppressed in typical tracker models if the late-time cosmic acceleration is driven at some field values near the Planck scale. We test ξ in a second class of models in which the field value today becomes a free model parameter. We use the combined data from type-Ia supernovae, cosmic microwave background, baryon acoustic oscillations and matter power spectrum, to weak lensing measurements and find a best-fit value ξ > 0.289 where ξ = 0 is excluded outside the 95% confidence region. The effective gravitational constant G{sub eff} subject to the hint of a non-zero ξ is constrained to -0.003 < 1 - G{sub eff}/G < 0.033 at the same confidence level on cosmological scales, and it can be narrowed down to 1 - G{sub eff}/G < 2.2 x 10{sup -5} when combining with Solar System tests. (orig.)
Unifying hydrotropy under Gibbs phase rule.
Shimizu, Seishi; Matubayasi, Nobuyuki
2017-09-13
The task of elucidating the mechanism of solubility enhancement using hydrotropes has been hampered by the wide variety of phase behaviour that hydrotropes can exhibit, encompassing near-ideal aqueous solution, self-association, micelle formation, and micro-emulsions. Instead of taking a field guide or encyclopedic approach to classify hydrotropes into different molecular classes, we take a rational approach aiming at constructing a unified theory of hydrotropy based upon the first principles of statistical thermodynamics. Achieving this aim can be facilitated by the two key concepts: (1) the Gibbs phase rule as the basis of classifying the hydrotropes in terms of the degrees of freedom and the number of variables to modulate the solvation free energy; (2) the Kirkwood-Buff integrals to quantify the interactions between the species and their relative contributions to the process of solubilization. We demonstrate that the application of the two key concepts can in principle be used to distinguish the different molecular scenarios at work under apparently similar solubility curves observed from experiments. In addition, a generalization of our previous approach to solutes beyond dilution reveals the unified mechanism of hydrotropy, driven by a strong solute-hydrotrope interaction which overcomes the apparent per-hydrotrope inefficiency due to hydrotrope self-clustering.
Minimizing the water and air impacts of unconventional energy extraction
Jackson, R. B.
2014-12-01
Unconventional energy generates income and, done well, can reduce air pollution compared to other fossil fuels and even water use compared to fossil fuels and nuclear energy. Alternatively, it could slow the adoption of renewables and, done poorly, release toxic chemicals into water and air. Based on research to date, some primary threats to water resources come from surface spills, wastewater disposal, and drinking-water contamination through poor well integrity. For air resources, an increase in volatile organic compounds and air toxics locally is a potential health threat, but the switch from coal to natural gas for electricity generation will reduce sulfur, nitrogen, mercury, and particulate pollution regionally. Critical needs for future research include data for 1) estimated ultimate recovery (EUR) of unconventional hydrocarbons; 2) the potential for further reductions of water requirements and chemical toxicity; 3) whether unconventional resource development alters the frequency of well-integrity failures; 4) potential contamination of surface and ground waters from drilling and spills; and 5) the consequences of greenhouse gases and air pollution on ecosystems and human health.
From slump loss to Gibbs' free energy
DEFF Research Database (Denmark)
Jensen, Ole Mejlhede; Diamond, Sidney
2006-01-01
In its classical form, the science of construction materials is a descriptive, empirical discipline related to certain types of materials, e.g. the study of the properties of wood, steel, concrete and plastics. This traditional division of the science into the separate study of the different...
Notes on the development of the gibbs potential; Sur le developpement du potentiel de gibbs
Energy Technology Data Exchange (ETDEWEB)
Bloch, C; Dominicis, C de [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires
1959-07-01
A short account is given of some recent work on the perturbation expansion of the Gibbs potential of quantum statistical mechanics. (author) [French] Expose en resume de quelques travaux sur le developpement dans la theorie des perturbations du potentiel de Gibbs de la Mecanique Statistique. (auteur)
A Comparative Study for Orthogonal Subspace Projection and Constrained Energy Minimization
National Research Council Canada - National Science Library
Du, Qian; Ren, Hsuan; Chang, Chein-I
2003-01-01
...: orthogonal subspace projection (OSP) and constrained energy minimization (CEM). It is shown that they are closely related and essentially equivalent provided that the noise is white with large SNR...
Evolution algebras generated by Gibbs measures
International Nuclear Information System (INIS)
Rozikov, Utkir A.; Tian, Jianjun Paul
2009-03-01
In this article we study algebraic structures of function spaces defined by graphs and state spaces equipped with Gibbs measures by associating evolution algebras. We give a constructive description of associating evolution algebras to the function spaces (cell spaces) defined by graphs and state spaces and Gibbs measure μ. For finite graphs we find some evolution subalgebras and other useful properties of the algebras. We obtain a structure theorem for evolution algebras when graphs are finite and connected. We prove that for a fixed finite graph, the function spaces have a unique algebraic structure since all evolution algebras are isomorphic to each other for whichever Gibbs measures are assigned. When graphs are infinite graphs then our construction allows a natural introduction of thermodynamics in studying of several systems of biology, physics and mathematics by theory of evolution algebras. (author)
The Use of Trust Regions in Kohn-Sham Total Energy Minimization
International Nuclear Information System (INIS)
Yang, Chao; Meza, Juan C.; Wang, Lin-wang
2006-01-01
The Self Consistent Field (SCF) iteration, widely used for computing the ground state energy and the corresponding single particle wave functions associated with a many-electron atomistic system, is viewed in this paper as an optimization procedure that minimizes the Kohn-Sham total energy indirectly by minimizing a sequence of quadratic surrogate functions. We point out the similarity and difference between the total energy and the surrogate, and show how the SCF iteration can fail when the minimizer of the surrogate produces an increase in the KS total energy. A trust region technique is introduced as a way to restrict the update of the wave functions within a small neighborhood of an approximate solution at which the gradient of the total energy agrees with that of the surrogate. The use of trust region in SCF is not new. However, it has been observed that directly applying a trust region based SCF(TRSCF) to the Kohn-Sham total energy often leads to slow convergence. We propose to use TRSCF within a direct constrained minimization(DCM) algorithm we developed in dcm. The key ingredients of the DCM algorithm involve projecting the total energy function into a sequence of subspaces of small dimensions and seeking the minimizer of the total energy function within each subspace. The minimizer of a subspace energy function, which is computed by TRSCF, not only provides a search direction along which the KS total energy function decreases but also gives an optimal 'step-length' that yields a sufficient decrease in total energy. A numerical example is provided to demonstrate that the combination of TRSCF and DCM is more efficient than SCF
Generalization of Gibbs Entropy and Thermodynamic Relation
Park, Jun Chul
2010-01-01
In this paper, we extend Gibbs's approach of quasi-equilibrium thermodynamic processes, and calculate the microscopic expression of entropy for general non-equilibrium thermodynamic processes. Also, we analyze the formal structure of thermodynamic relation in non-equilibrium thermodynamic processes.
Finite Cycle Gibbs Measures on Permutations of
Armendáriz, Inés; Ferrari, Pablo A.; Groisman, Pablo; Leonardi, Florencia
2015-03-01
We consider Gibbs distributions on the set of permutations of associated to the Hamiltonian , where is a permutation and is a strictly convex potential. Call finite-cycle those permutations composed by finite cycles only. We give conditions on ensuring that for large enough temperature there exists a unique infinite volume ergodic Gibbs measure concentrating mass on finite-cycle permutations; this measure is equal to the thermodynamic limit of the specifications with identity boundary conditions. We construct as the unique invariant measure of a Markov process on the set of finite-cycle permutations that can be seen as a loss-network, a continuous-time birth and death process of cycles interacting by exclusion, an approach proposed by Fernández, Ferrari and Garcia. Define as the shift permutation . In the Gaussian case , we show that for each , given by is an ergodic Gibbs measure equal to the thermodynamic limit of the specifications with boundary conditions. For a general potential , we prove the existence of Gibbs measures when is bigger than some -dependent value.
Gibbs equilibrium averages and Bogolyubov measure
International Nuclear Information System (INIS)
Sankovich, D.P.
2011-01-01
Application of the functional integration methods in equilibrium statistical mechanics of quantum Bose-systems is considered. We show that Gibbs equilibrium averages of Bose-operators can be represented as path integrals over a special Gauss measure defined in the corresponding space of continuous functions. We consider some problems related to integration with respect to this measure
Free energy minimization to predict RNA secondary structures and computational RNA design.
Churkin, Alexander; Weinbrand, Lina; Barash, Danny
2015-01-01
Determining the RNA secondary structure from sequence data by computational predictions is a long-standing problem. Its solution has been approached in two distinctive ways. If a multiple sequence alignment of a collection of homologous sequences is available, the comparative method uses phylogeny to determine conserved base pairs that are more likely to form as a result of billions of years of evolution than by chance. In the case of single sequences, recursive algorithms that compute free energy structures by using empirically derived energy parameters have been developed. This latter approach of RNA folding prediction by energy minimization is widely used to predict RNA secondary structure from sequence. For a significant number of RNA molecules, the secondary structure of the RNA molecule is indicative of its function and its computational prediction by minimizing its free energy is important for its functional analysis. A general method for free energy minimization to predict RNA secondary structures is dynamic programming, although other optimization methods have been developed as well along with empirically derived energy parameters. In this chapter, we introduce and illustrate by examples the approach of free energy minimization to predict RNA secondary structures.
Duijns, S.; Dijk, van J.G.B.; Spaans, B.; Jukema, J.; Boer, de W.F.; Piersma, Th.
2009-01-01
Different spatial distributions of food abundance and predators may urge birds to make a trade-off between food intake and danger. Such a trade-off might be solved in different ways in migrant birds that either follow a time-minimizing or energy-minimizing strategy; these strategies have been
Duijns, Sjoerd; van Dijk, Jacintha G. B.; Spaans, Bernard; Jukema, Joop; de Boer, Willem F.; Piersma, Theunis
2009-01-01
Different spatial distributions Of food abundance and predators may urge birds to make a trade-off between food intake and danger. Such a trade-off might be solved in different ways in migrant birds that either follow a time-minimizing or energy-minimizing strategy; these strategies have been
International Nuclear Information System (INIS)
Choi, C. Y.
1997-01-01
A geometrical inverse heat conduction problem is solved for the infrared scanning cavity detection by the boundary element method using minimal energy technique. By minimizing the kinetic energy of temperature field, boundary element equations are converted to the quadratic programming problem. A hypothetical inner boundary is defined such that the actual cavity is located interior to the domain. Temperatures at hypothetical inner boundary are determined to meet the constraints of measurement error of surface temperature obtained by infrared scanning, and then boundary element analysis is performed for the position of an unknown boundary (cavity). Cavity detection algorithm is provided, and the effects of minimal energy technique on the inverse solution method are investigated by means of numerical analysis
Three-Dimensional Dirac Oscillator with Minimal Length: Novel Phenomena for Quantized Energy
Directory of Open Access Journals (Sweden)
Malika Betrouche
2013-01-01
Full Text Available We study quantum features of the Dirac oscillator under the condition that the position and the momentum operators obey generalized commutationrelations that lead to the appearance of minimal length with the order of the Planck length, ∆xmin=ℏ3β+β′, where β and β′ are two positive small parameters. Wave functions of the system and the corresponding energy spectrum are derived rigorously. The presence of the minimal length accompanies a quadratic dependence of the energy spectrum on quantum number n, implying the property of hard confinement of the system. It is shown that the infinite degeneracy of energy levels appearing in the usual Dirac oscillator is vanished by the presence of the minimal length so long as β≠0. Not only in the nonrelativistic limit but also in the limit of the standard case (β=β′=0, our results reduce to well known usual ones.
Molecular mechanics calculations of proteins. Comparison of different energy minimization strategies
DEFF Research Database (Denmark)
Christensen, I T; Jørgensen, Flemming Steen
1997-01-01
A general strategy for performing energy minimization of proteins using the SYBYL molecular modelling program has been developed. The influence of several variables including energy minimization procedure, solvation, dielectric function and dielectric constant have been investigated in order...... to develop a general method, which is capable of producing high quality protein structures. Avian pancreatic polypeptide (APP) and bovine pancreatic phospholipase A2 (BP PLA2) were selected for the calculations, because high quality X-ray structures exist and because all classes of secondary structure...... for this protein. Energy minimized structures of the trimeric PLA2 from Indian cobra (N.n.n. PLA2) were used for assessing the impact of protein-protein interactions. Based on the above mentioned criteria, it could be concluded that using the following conditions: Dielectric constant epsilon = 4 or 20; a distance...
Smart HVAC Control in IoT: Energy Consumption Minimization with User Comfort Constraints
Directory of Open Access Journals (Sweden)
Jordi Serra
2014-01-01
of heating, ventilation, and air conditioning (HVAC systems in smart grids with variable energy price. To that end, first, we propose an energy scheduling method that minimizes the energy consumption cost for a particular time interval, taking into account the energy price and a set of comfort constraints, that is, a range of temperatures according to user’s preferences for a given room. Then, we propose an energy scheduler where the user may select to relax the temperature constraints to save more energy. Moreover, thanks to the IoT paradigm, the user may interact remotely with the HVAC control system. In particular, the user may decide remotely the temperature of comfort, while the temperature and energy consumption information is sent through Internet and displayed at the end user’s device. The proposed algorithms have been implemented in a real testbed, highlighting the potential gains that can be achieved in terms of both energy and cost.
Gibbs sampling on large lattice with GMRF
Marcotte, Denis; Allard, Denis
2018-02-01
Gibbs sampling is routinely used to sample truncated Gaussian distributions. These distributions naturally occur when associating latent Gaussian fields to category fields obtained by discrete simulation methods like multipoint, sequential indicator simulation and object-based simulation. The latent Gaussians are often used in data assimilation and history matching algorithms. When the Gibbs sampling is applied on a large lattice, the computing cost can become prohibitive. The usual practice of using local neighborhoods is unsatisfying as it can diverge and it does not reproduce exactly the desired covariance. A better approach is to use Gaussian Markov Random Fields (GMRF) which enables to compute the conditional distributions at any point without having to compute and invert the full covariance matrix. As the GMRF is locally defined, it allows simultaneous updating of all points that do not share neighbors (coding sets). We propose a new simultaneous Gibbs updating strategy on coding sets that can be efficiently computed by convolution and applied with an acceptance/rejection method in the truncated case. We study empirically the speed of convergence, the effect of choice of boundary conditions, of the correlation range and of GMRF smoothness. We show that the convergence is slower in the Gaussian case on the torus than for the finite case studied in the literature. However, in the truncated Gaussian case, we show that short scale correlation is quickly restored and the conditioning categories at each lattice point imprint the long scale correlation. Hence our approach enables to realistically apply Gibbs sampling on large 2D or 3D lattice with the desired GMRF covariance.
An efficient estimator for Gibbs random fields
Czech Academy of Sciences Publication Activity Database
Janžura, Martin
2014-01-01
Roč. 50, č. 6 (2014), s. 883-895 ISSN 0023-5954 R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional support: RVO:67985556 Keywords : Gibbs random field * efficient estimator * empirical estimator Subject RIV: BA - General Mathematics Impact factor: 0.541, year: 2014 http://library.utia.cas.cz/separaty/2015/SI/janzura-0441325.pdf
Sectors of solutions and minimal energies in classical Liouville theories for strings
International Nuclear Information System (INIS)
Johansson, L.; Kihlberg, A.; Marnelius, R.
1984-01-01
All classical solutions of the Liouville theory for strings having finite stable minimum energies are calculated explicitly together with their minimal energies. Our treatment automatically includes the set of natural solitonlike singularities described by Jorjadze, Pogrebkov, and Polivanov. Since the number of such singularities is preserved in time, a sector of solutions is not only characterized by its boundary conditions but also by its number of singularities. Thus, e.g., the Liouville theory with periodic boundary conditions has three different sectors of solutions with stable minimal energies containing zero, one, and two singularities. (Solutions with more singularities have no stable minimum energy.) It is argued that singular solutions do not make the string singular and therefore may be included in the string quantization
Energy-minimized design in all-optical networks using unicast/multicast traffic grooming
Puche, William S.; Amaya, Ferney O.; Sierra, Javier E.
2013-09-01
The increased bandwidth required by applications, tends to raise the amount of optical equipment, for this reason, it is essential to maintain a balance between the wavelength allocation, available capacity and number of optical devices to achieve the lowest power consumption. You could say that we propose a model that minimizes energy consumption, using unicast / multicast traffic grooming in optical networks.
Online Speed Scaling Based on Active Job Count to Minimize Flow Plus Energy
DEFF Research Database (Denmark)
Lam, Tak-Wah; Lee, Lap Kei; To, Isaac K. K.
2013-01-01
This paper is concerned with online scheduling algorithms that aim at minimizing the total flow time plus energy usage. The results are divided into two parts. First, we consider the well-studied “simple” speed scaling model and show how to analyze a speed scaling algorithm (called AJC) that chan...
Minimizing the Free Energy: A Computer Method for Teaching Chemical Equilibrium Concepts.
Heald, Emerson F.
1978-01-01
Presents a computer method for teaching chemical equilibrium concepts using material balance conditions and the minimization of the free energy. Method for the calculation of chemical equilibrium, the computer program used to solve equilibrium problems and applications of the method are also included. (HM)
Work and entropy production in generalised Gibbs ensembles
International Nuclear Information System (INIS)
Perarnau-Llobet, Martí; Riera, Arnau; Gallego, Rodrigo; Wilming, Henrik; Eisert, Jens
2016-01-01
Recent years have seen an enormously revived interest in the study of thermodynamic notions in the quantum regime. This applies both to the study of notions of work extraction in thermal machines in the quantum regime, as well as to questions of equilibration and thermalisation of interacting quantum many-body systems as such. In this work we bring together these two lines of research by studying work extraction in a closed system that undergoes a sequence of quenches and equilibration steps concomitant with free evolutions. In this way, we incorporate an important insight from the study of the dynamics of quantum many body systems: the evolution of closed systems is expected to be well described, for relevant observables and most times, by a suitable equilibrium state. We will consider three kinds of equilibration, namely to (i) the time averaged state, (ii) the Gibbs ensemble and (iii) the generalised Gibbs ensemble, reflecting further constants of motion in integrable models. For each effective description, we investigate notions of entropy production, the validity of the minimal work principle and properties of optimal work extraction protocols. While we keep the discussion general, much room is dedicated to the discussion of paradigmatic non-interacting fermionic quantum many-body systems, for which we identify significant differences with respect to the role of the minimal work principle. Our work not only has implications for experiments with cold atoms, but also can be viewed as suggesting a mindset for quantum thermodynamics where the role of the external heat baths is instead played by the system itself, with its internal degrees of freedom bringing coarse-grained observables to equilibrium. (paper)
Energy levels of one-dimensional systems satisfying the minimal length uncertainty relation
Energy Technology Data Exchange (ETDEWEB)
Bernardo, Reginald Christian S., E-mail: rcbernardo@nip.upd.edu.ph; Esguerra, Jose Perico H., E-mail: jesguerra@nip.upd.edu.ph
2016-10-15
The standard approach to calculating the energy levels for quantum systems satisfying the minimal length uncertainty relation is to solve an eigenvalue problem involving a fourth- or higher-order differential equation in quasiposition space. It is shown that the problem can be reformulated so that the energy levels of these systems can be obtained by solving only a second-order quasiposition eigenvalue equation. Through this formulation the energy levels are calculated for the following potentials: particle in a box, harmonic oscillator, Pöschl–Teller well, Gaussian well, and double-Gaussian well. For the particle in a box, the second-order quasiposition eigenvalue equation is a second-order differential equation with constant coefficients. For the harmonic oscillator, Pöschl–Teller well, Gaussian well, and double-Gaussian well, a method that involves using Wronskians has been used to solve the second-order quasiposition eigenvalue equation. It is observed for all of these quantum systems that the introduction of a nonzero minimal length uncertainty induces a positive shift in the energy levels. It is shown that the calculation of energy levels in systems satisfying the minimal length uncertainty relation is not limited to a small number of problems like particle in a box and the harmonic oscillator but can be extended to a wider class of problems involving potentials such as the Pöschl–Teller and Gaussian wells.
Cooperative Content Distribution over Wireless Networks for Energy and Delay Minimization
Atat, Rachad
2012-06-01
Content distribution with mobile-to-mobile cooperation is studied. Data is sent to mobile terminals on a long range link then the terminals exchange the content using an appropriate short range wireless technology. Unicasting and multicasting are investigated, both on the long range and short range links. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form. Moreover, the schemes are applied in public safety vehicular networks, where Long Term Evolution (LTE) network is used for the long range link, while IEEE 802.11 p is considered for inter-vehicle collaboration on the short range links. Finally, relay-based multicasting is applied in high speed trains for energy and delay minimization. Results show that cooperative schemes outperform non-cooperative ones and other previous related work in terms of energy and delay savings. Furthermore, practical implementation aspects of the proposed methods are also discussed.
International Nuclear Information System (INIS)
Hubbard, Linda M.; Galen, Glen R.
1992-01-01
Waste minimization has become an important consideration in the management of hazardous waste because of regulatory as well as cost considerations. Waste minimization techniques are often process specific or industry specific and generally are not applicable to site remediation activities. This paper will examine ways in which waste can be minimized in a remediation setting such as the U.S. Department of Energy's Formerly Utilized Sites Remedial Action Program, where the bulk of the waste produced results from remediating existing contamination, not from generating new waste. (author)
Energy Technology Data Exchange (ETDEWEB)
Van Pelt, R. S.; Amidon, M. B.; Reboul, S. H.
2002-02-25
Environmental restoration activities at the Department of Energy Savannah River Site (SRS) utilize innovative site characterization approaches and technologies that minimize waste generation. Characterization is typically conducted in phases, first by collecting large quantities of inexpensive data, followed by targeted minimally invasive drilling to collect depth-discrete soil/groundwater data, and concluded with the installation of permanent multi-level groundwater monitoring wells. Waste-reducing characterization methods utilize non-traditional drilling practices (sonic drilling), minimally intrusive (geoprobe, cone penetrometer) and non-intrusive (3-D seismic, ground penetration radar, aerial monitoring) investigative tools. Various types of sensor probes (moisture sensors, gamma spectroscopy, Raman spectroscopy, laser induced and X-ray fluorescence) and hydrophobic membranes (FLUTe) are used in conjunction with depth-discrete sampling techniques to obtain high-resolution 3-D plume profiles. Groundwater monitoring (short/long-term) approaches utilize multi-level sampling technologies (Strata-Sampler, Cone-Sipper, Solinst Waterloo, Westbay) and low-cost diffusion samplers for seepline/surface water sampling. Upon collection of soil and groundwater data, information is portrayed in a Geographic Information Systems (GIS) format for interpretation and planning purposes. At the SRS, the use of non-traditional drilling methods and minimally/non intrusive investigation approaches along with in-situ sampling methods has minimized waste generation and improved the effectiveness and efficiency of characterization activities.
International Nuclear Information System (INIS)
Van Pelt, R. S.; Amidon, M. B.; Reboul, S. H.
2002-01-01
Environmental restoration activities at the Department of Energy Savannah River Site (SRS) utilize innovative site characterization approaches and technologies that minimize waste generation. Characterization is typically conducted in phases, first by collecting large quantities of inexpensive data, followed by targeted minimally invasive drilling to collect depth-discrete soil/groundwater data, and concluded with the installation of permanent multi-level groundwater monitoring wells. Waste-reducing characterization methods utilize non-traditional drilling practices (sonic drilling), minimally intrusive (geoprobe, cone penetrometer) and non-intrusive (3-D seismic, ground penetration radar, aerial monitoring) investigative tools. Various types of sensor probes (moisture sensors, gamma spectroscopy, Raman spectroscopy, laser induced and X-ray fluorescence) and hydrophobic membranes (FLUTe) are used in conjunction with depth-discrete sampling techniques to obtain high-resolution 3-D plume profiles. Groundwater monitoring (short/long-term) approaches utilize multi-level sampling technologies (Strata-Sampler, Cone-Sipper, Solinst Waterloo, Westbay) and low-cost diffusion samplers for seepline/surface water sampling. Upon collection of soil and groundwater data, information is portrayed in a Geographic Information Systems (GIS) format for interpretation and planning purposes. At the SRS, the use of non-traditional drilling methods and minimally/non intrusive investigation approaches along with in-situ sampling methods has minimized waste generation and improved the effectiveness and efficiency of characterization activities
Kang, Donghun; Lee, Jungeon; Jung, Jongpil; Lee, Chul-Hee; Kyung, Chong-Min
2014-09-01
In mobile video systems powered by battery, reducing the encoder's compression energy consumption is critical to prolong its lifetime. Previous Energy-rate-distortion (E-R-D) optimization methods based on a software codec is not suitable for practical mobile camera systems because the energy consumption is too large and encoding rate is too low. In this paper, we propose an E-R-D model for the hardware codec based on the gate-level simulation framework to measure the switching activity and the energy consumption. From the proposed E-R-D model, an energy minimizing algorithm for mobile video camera sensor have been developed with the GOP (Group of Pictures) size and QP(Quantization Parameter) as run-time control variables. Our experimental results show that the proposed algorithm provides up to 31.76% of energy consumption saving while satisfying the rate and distortion constraints.
Sochi, Taha
2016-09-01
Several deterministic and stochastic multi-variable global optimization algorithms (Conjugate Gradient, Nelder-Mead, Quasi-Newton and global) are investigated in conjunction with energy minimization principle to resolve the pressure and volumetric flow rate fields in single ducts and networks of interconnected ducts. The algorithms are tested with seven types of fluid: Newtonian, power law, Bingham, Herschel-Bulkley, Ellis, Ree-Eyring and Casson. The results obtained from all those algorithms for all these types of fluid agree very well with the analytically derived solutions as obtained from the traditional methods which are based on the conservation principles and fluid constitutive relations. The results confirm and generalize the findings of our previous investigations that the energy minimization principle is at the heart of the flow dynamics systems. The investigation also enriches the methods of computational fluid dynamics for solving the flow fields in tubes and networks for various types of Newtonian and non-Newtonian fluids.
Energy Technology Data Exchange (ETDEWEB)
Meneses, Anderson A.M. [Federal University of Western Para (Brazil); Physics Institute, Rio de Janeiro State University (Brazil); Giusti, Alessandro [IDSIA (Dalle Molle Institute for Artificial Intelligence), University of Lugano (Switzerland); Almeida, Andre P. de, E-mail: apalmeid@gmail.com [Physics Institute, Rio de Janeiro State University (Brazil); Nuclear Engineering Program, Federal University of Rio de Janeiro (Brazil); Nogueira, Liebert; Braz, Delson [Nuclear Engineering Program, Federal University of Rio de Janeiro (Brazil); Almeida, Carlos E. de [Radiological Sciences Laboratory, Rio de Janeiro State University (Brazil); Barroso, Regina C. [Physics Institute, Rio de Janeiro State University (Brazil)
2012-07-15
The research on applications of segmentation algorithms to Synchrotron Radiation X-Ray micro-Computed Tomography (SR-{mu}CT) is an open problem, due to the interesting and well-known characteristics of SR images, such as the phase contrast effect. The Energy Minimization via Graph Cuts (EMvGC) algorithm represents state-of-art segmentation algorithm, presenting an enormous potential of application in SR-{mu}CT imaging. We describe the application of the algorithm EMvGC with swap move for the segmentation of bone images acquired at the ELETTRA Laboratory (Trieste, Italy). - Highlights: Black-Right-Pointing-Pointer Microstructures of Wistar rats' ribs are investigated with Synchrotron Radiation {mu}CT imaging. Black-Right-Pointing-Pointer The present work is part of a research on the effects of radiotherapy on the thoracic region. Black-Right-Pointing-Pointer Application of the Energy Minimization via Graph Cuts algorithm for segmentation is described.
DEFF Research Database (Denmark)
Terp, G E; Christensen, I T; Jørgensen, Flemming Steen
2000-01-01
Matrix metalloproteinases are extracellular enzymes taking part in the remodeling of extracellular matrix. The structures of the catalytic domain of MMP1, MMP3, MMP7 and MMP8 are known, but structures of enzymes belonging to this family still remain to be determined. A general approach...... to the homology modeling of matrix metalloproteinases, exemplified by the modeling of MMP2, MMP9, MMP12 and MMP14 is described. The models were refined using an energy minimization procedure developed for matrix metalloproteinases. This procedure includes incorporation of parameters for zinc and calcium ions...... in the AMBER 4.1 force field, applying a non-bonded approach and a full ion charge representation. Energy minimization of the apoenzymes yielded structures with distorted active sites, while reliable three-dimensional structures of the enzymes containing a substrate in active site were obtained. The structural...
Market clearing of joint energy and reserves auctions using augmented payment minimization
International Nuclear Information System (INIS)
Amjady, N.; Aghaei, J.; Shayanfar, H.A.
2009-01-01
This paper presents the market clearing of joint energy and reserves auctions and its mathematical formulation, focusing on a possible implementation of the Payment Cost Minimization (PCM). It also discusses another key point in debate: whether market clearing algorithm should minimize offer costs or payment costs? An aggregated simultaneous market clearing approach is proposed for provision of ancillary services as well as energy, which is in the form of Mixed Integer Nonlinear Programming (MINLP) formulation. In the MINLP formulation of the market clearing process, the objective function (Payment cost or offer cost) are optimized while meeting AC power flow constraints, system reserve requirements and lost opportunity cost (LOC) considerations. The model is applied to the IEEE 24-bus Reliability Test System (IEEE 24-bus RTS), and simulation studies are carried out to examine the effectiveness of each objective function. (author)
International Nuclear Information System (INIS)
Meneses, Anderson A.M.; Giusti, Alessandro; Almeida, André P. de; Nogueira, Liebert; Braz, Delson; Almeida, Carlos E. de; Barroso, Regina C.
2012-01-01
The research on applications of segmentation algorithms to Synchrotron Radiation X-Ray micro-Computed Tomography (SR-μCT) is an open problem, due to the interesting and well-known characteristics of SR images, such as the phase contrast effect. The Energy Minimization via Graph Cuts (EMvGC) algorithm represents state-of-art segmentation algorithm, presenting an enormous potential of application in SR-μCT imaging. We describe the application of the algorithm EMvGC with swap move for the segmentation of bone images acquired at the ELETTRA Laboratory (Trieste, Italy). - Highlights: ► Microstructures of Wistar rats' ribs are investigated with Synchrotron Radiation μCT imaging. ► The present work is part of a research on the effects of radiotherapy on the thoracic region. ► Application of the Energy Minimization via Graph Cuts algorithm for segmentation is described.
A non-minimally coupled quintom dark energy model on the warped DGP brane
International Nuclear Information System (INIS)
Nozari, K; Azizi, T; Setare, M R; Behrouz, N
2009-01-01
We construct a quintom dark energy model with two non-minimally coupled scalar fields, one quintessence and the other phantom field, confined to the warped Dvali-Gabadadze-Porrati (DGP) brane. We show that this model accounts for crossing of the phantom divide line in appropriate subspaces of the model parameter space. This crossing occurs for both normal and self-accelerating branches of this DGP-inspired setup.
Directory of Open Access Journals (Sweden)
V. N. Nagornov
2012-01-01
Full Text Available The paper contains a classification of internal and external threats for thermal power plants and recommendations on minimization of these risks. A set of concrete measures aimed at ensuring TPP energy security has been presented in the paper. The system comprises preventive measures aimed at reducing the possibilities of emergence and implementation of internal and external threats. The system also presupposes to decrease susceptibility of fuel- and energy supply systems to the threats, and application of liquidation measures that ensure elimination of emergency situation consequences and restoration of the conditions concerning fuel- and power supply to consumers.
Power allocation strategies to minimize energy consumption in wireless body area networks.
Kailas, Aravind
2011-01-01
The wide scale deployment of wireless body area networks (WBANs) hinges on designing energy efficient communication protocols to support the reliable communication as well as to prolong the network lifetime. Cooperative communications, a relatively new idea in wireless communications, offers the benefits of multi-antenna systems, thereby improving the link reliability and boosting energy efficiency. In this short paper, the advantages of resorting to cooperative communications for WBANs in terms of minimized energy consumption are investigated. Adopting an energy model that encompasses energy consumptions in the transmitter and receiver circuits, and transmitting energy per bit, it is seen that cooperative transmission can improve energy efficiency of the wireless network. In particular, the problem of optimal power allocation is studied with the constraint of targeted outage probability. Two strategies of power allocation are considered: power allocation with and without posture state information. Using analysis and simulation-based results, two key points are demonstrated: (i) allocating power to the on-body sensors making use of the posture information can reduce the total energy consumption of the WBAN; and (ii) when the channel condition is good, it is better to recruit less relays for cooperation to enhance energy efficiency.
Smart HVAC control in IoT: energy consumption minimization with user comfort constraints.
Serra, Jordi; Pubill, David; Antonopoulos, Angelos; Verikoukis, Christos
2014-01-01
Smart grid is one of the main applications of the Internet of Things (IoT) paradigm. Within this context, this paper addresses the efficient energy consumption management of heating, ventilation, and air conditioning (HVAC) systems in smart grids with variable energy price. To that end, first, we propose an energy scheduling method that minimizes the energy consumption cost for a particular time interval, taking into account the energy price and a set of comfort constraints, that is, a range of temperatures according to user's preferences for a given room. Then, we propose an energy scheduler where the user may select to relax the temperature constraints to save more energy. Moreover, thanks to the IoT paradigm, the user may interact remotely with the HVAC control system. In particular, the user may decide remotely the temperature of comfort, while the temperature and energy consumption information is sent through Internet and displayed at the end user's device. The proposed algorithms have been implemented in a real testbed, highlighting the potential gains that can be achieved in terms of both energy and cost.
Wai, C. M.; Hutchinson, S. G.
1989-01-01
Discusses the calculation of free energy in reactions between silicon dioxide and carbon. Describes several computer programs for calculating the free energy minimization and their uses in chemistry classrooms. Lists 16 references. (YP)
New insights gained on mechanisms of low-energy proton-induced SEUs by minimizing energy straggle
International Nuclear Information System (INIS)
Dodds, Nathaniel Anson; Dodd, Paul E.; Shaneyfelt, Marty R.; Sexton, Frederick W.; Martinez, Marino J.; Black, Jeffrey D.; Marshall, P. W.; Reed, R. A.; McCurdy, M. W.; Weller, R. A.; Pellish, J. A.; Rodbell, K. P.; Gordon, M. S.
2015-01-01
In this study, we present low-energy proton single-event upset (SEU) data on a 65 nm SOI SRAM whose substrate has been completely removed. Since the protons only had to penetrate a very thin buried oxide layer, these measurements were affected by far less energy loss, energy straggle, flux attrition, and angular scattering than previous datasets. The minimization of these common sources of experimental interference allows more direct interpretation of the data and deeper insight into SEU mechanisms. The results show a strong angular dependence, demonstrate that energy straggle, flux attrition, and angular scattering affect the measured SEU cross sections, and prove that proton direct ionization is the dominant mechanism for low-energy proton-induced SEUs in these circuits
Surles, M C; Richardson, J S; Richardson, D C; Brooks, F P
1994-02-01
We describe a new paradigm for modeling proteins in interactive computer graphics systems--continual maintenance of a physically valid representation, combined with direct user control and visualization. This is achieved by a fast algorithm for energy minimization, capable of real-time performance on all atoms of a small protein, plus graphically specified user tugs. The modeling system, called Sculpt, rigidly constrains bond lengths, bond angles, and planar groups (similar to existing interactive modeling programs), while it applies elastic restraints to minimize the potential energy due to torsions, hydrogen bonds, and van der Waals and electrostatic interactions (similar to existing batch minimization programs), and user-specified springs. The graphical interface can show bad and/or favorable contacts, and individual energy terms can be turned on or off to determine their effects and interactions. Sculpt finds a local minimum of the total energy that satisfies all the constraints using an augmented Lagrange-multiplier method; calculation time increases only linearly with the number of atoms because the matrix of constraint gradients is sparse and banded. On a 100-MHz MIPS R4000 processor (Silicon Graphics Indigo), Sculpt achieves 11 updates per second on a 20-residue fragment and 2 updates per second on an 80-residue protein, using all atoms except non-H-bonding hydrogens, and without electrostatic interactions. Applications of Sculpt are described: to reverse the direction of bundle packing in a designed 4-helix bundle protein, to fold up a 2-stranded beta-ribbon into an approximate beta-barrel, and to design the sequence and conformation of a 30-residue peptide that mimics one partner of a protein subunit interaction. Computer models that are both interactive and physically realistic (within the limitations of a given force field) have 2 significant advantages: (1) they make feasible the modeling of very large changes (such as needed for de novo design), and
Fuzzy-TLBO optimal reactive power control variables planning for energy loss minimization
International Nuclear Information System (INIS)
Moghadam, Ahmad; Seifi, Ali Reza
2014-01-01
Highlights: • A new approach to the problem of optimal reactive power control variables planning is proposed. • The energy loss minimization problem has been formulated by modeling the load of system as a Load Duration Curve. • To solving the energy loss problem, the classic methods and the evolutionary methods are used. • A new proposed fuzzy teaching–learning based algorithm is applied to energy loss problem. • Simulations are done to show the effectiveness and superiority of the proposed algorithm compared with other methods. - Abstract: This paper offers a new approach to the problem of optimal reactive power control variables planning (ORPVCP). The basic idea is division of Load Duration Curve (LDC) into several time intervals with constant active power demand in each interval and then solving the energy loss minimization (ELM) problem to obtain an optimal initial set of control variables of the system so that is valid for all time intervals and can be used as an initial operating condition of the system. In this paper, the ELM problem has been solved by the linear programming (LP) and fuzzy linear programming (Fuzzy-LP) and evolutionary algorithms i.e. MHBMO and TLBO and the results are compared with the proposed Fuzzy-TLBO method. In the proposed method both objective function and constraints are evaluated by membership functions. The inequality constraints are embedded into the fitness function by the membership function of the fuzzy decision and the problem is modeled by fuzzy set theory. The proposed Fuzzy-TLBO method is performed on the IEEE 30 bus test system by considering two different LDC; and it is shown that using this method has further minimized objective function than original TLBO and other optimization techniques and confirms its potential to solve the ORPCVP problem with considering ELM as the objective function
Ten scenarios from early radiation to late time acceleration with a minimally coupled dark energy
Energy Technology Data Exchange (ETDEWEB)
Fay, Stéphane, E-mail: steph.fay@gmail.com [Palais de la Découverte, Astronomy Department, Avenue Franklin Roosevelt, 75008 Paris (France)
2013-09-01
We consider General Relativity with matter, radiation and a minimally coupled dark energy defined by an equation of state w. Using dynamical system method, we find the equilibrium points of such a theory assuming an expanding Universe and a positive dark energy density. Two of these points correspond to classical radiation and matter dominated epochs for the Universe. For the other points, dark energy mimics matter, radiation or accelerates Universe expansion. We then look for possible sequences of epochs describing a Universe starting with some radiation dominated epoch(s) (mimicked or not by dark energy), then matter dominated epoch(s) (mimicked or not by dark energy) and ending with an accelerated expansion. We find ten sequences able to follow this Universe history without singular behaviour of w at some saddle points. Most of them are new in dark energy literature. To get more than these ten sequences, w has to be singular at some specific saddle equilibrium points. This is an unusual mathematical property of the equation of state in dark energy literature, whose physical consequences tend to be discarded by observations. This thus distinguishes the ten above sequences from an infinity of ways to describe Universe expansion.
Ten scenarios from early radiation to late time acceleration with a minimally coupled dark energy
International Nuclear Information System (INIS)
Fay, Stéphane
2013-01-01
We consider General Relativity with matter, radiation and a minimally coupled dark energy defined by an equation of state w. Using dynamical system method, we find the equilibrium points of such a theory assuming an expanding Universe and a positive dark energy density. Two of these points correspond to classical radiation and matter dominated epochs for the Universe. For the other points, dark energy mimics matter, radiation or accelerates Universe expansion. We then look for possible sequences of epochs describing a Universe starting with some radiation dominated epoch(s) (mimicked or not by dark energy), then matter dominated epoch(s) (mimicked or not by dark energy) and ending with an accelerated expansion. We find ten sequences able to follow this Universe history without singular behaviour of w at some saddle points. Most of them are new in dark energy literature. To get more than these ten sequences, w has to be singular at some specific saddle equilibrium points. This is an unusual mathematical property of the equation of state in dark energy literature, whose physical consequences tend to be discarded by observations. This thus distinguishes the ten above sequences from an infinity of ways to describe Universe expansion
Directory of Open Access Journals (Sweden)
Tarek FOUDA
2015-06-01
Full Text Available The experimental work was carried out through agricultural summer season of 2014 at the experimental farm of Gemmiza Research Station, Gharbiya governorate to minimize energy and costs in weeding and fertilizing processes for fiber crops (Kenaf and Roselle in small farms. The manufactured multipurpose unit performance was studied as a function of change in machine forward speed (2.2, 2.8, 3.4 and 4 Km/h fertilizing rates (30,45 and 60 Kg.N.fed-1,and constant soil moisture content was 20%(d.b in average. Performance of the manufactured machine was evaluated in terms of fuel consumption, power and energy requirements, effective field capacity, theoretical field capacity, field efficiency, and operational costs as a machine measurements .The experiment results reveled that the manufactured machine decreased energy and increased effective field capacity and efficiency under the following conditions: -machine forward speed 2.2Kmlh. -moisture content average 20%.
Oda, Takuya; Akisawa, Atushi; Kashiwagi, Takao
If the economic activity in the commercial and residential sector continues to grow, improvement in energy conversion efficiencies of energy supply systems is necessary for CO2 mitigation. In recent years, the electricity driven hot water heat pump (EDHP) and the solar photo voltaic (PV) are commercialized. The fuel cell (FC) of co-generation system (CGS) for the commercial and residential sector will be commercialized in the future. The aim is to indicate the ideal energy supply system of the users sector, which both manages the economical cost and CO2 mitigation, considering the grid power system. In the paper, cooperative Japanese energy supply systems are modeled by linear-programming. It includes the grid power system and energy systems of five commercial sectors and a residential sector. The demands of sectors are given by the objective term for 2005 to 2025. 24 hours load for each 3 annual seasons are considered. The energy systems are simulated to be minimize the total cost of energy supply, and to be mitigate the CO2 discharge. As result, the ideal energy system at 2025 is shown. The CGS capacity grows to 30% (62GW) of total power system, and the EDHP capacity is 26GW, in commercial and residential sectors.
Predicting Consensus Structures for RNA Alignments Via Pseudo-Energy Minimization
Directory of Open Access Journals (Sweden)
Junilda Spirollari
2009-01-01
Full Text Available Thermodynamic processes with free energy parameters are often used in algorithms that solve the free energy minimization problem to predict secondary structures of single RNA sequences. While results from these algorithms are promising, an observation is that single sequence-based methods have moderate accuracy and more information is needed to improve on RNA secondary structure prediction, such as covariance scores obtained from multiple sequence alignments. We present in this paper a new approach to predicting the consensus secondary structure of a set of aligned RNA sequences via pseudo-energy minimization. Our tool, called RSpredict, takes into account sequence covariation and employs effective heuristics for accuracy improvement. RSpredict accepts, as input data, a multiple sequence alignment in FASTA or ClustalW format and outputs the consensus secondary structure of the input sequences in both the Vienna style Dot Bracket format and the Connectivity Table format. Our method was compared with some widely used tools including KNetFold, Pfold and RNAalifold. A comprehensive test on different datasets including Rfam sequence alignments and a multiple sequence alignment obtained from our study on the Drosophila X chromosome reveals that RSpredict is competitive with the existing tools on the tested datasets. RSpredict is freely available online as a web server and also as a jar file for download at http:// datalab.njit.edu/biology/RSpredict.
Askerov, Bahram M
2010-01-01
This book deals with theoretical thermodynamics and the statistical physics of electron and particle gases. While treating the laws of thermodynamics from both classical and quantum theoretical viewpoints, it posits that the basis of the statistical theory of macroscopic properties of a system is the microcanonical distribution of isolated systems, from which all canonical distributions stem. To calculate the free energy, the Gibbs method is applied to ideal and non-ideal gases, and also to a crystalline solid. Considerable attention is paid to the Fermi-Dirac and Bose-Einstein quantum statistics and its application to different quantum gases, and electron gas in both metals and semiconductors is considered in a nonequilibrium state. A separate chapter treats the statistical theory of thermodynamic properties of an electron gas in a quantizing magnetic field.
Neff, Patrizio; Lankeit, Johannes; Ghiba, Ionel-Dumitrel; Martin, Robert; Steigmann, David
2015-08-01
We consider a family of isotropic volumetric-isochoric decoupled strain energies based on the Hencky-logarithmic (true, natural) strain tensor log U, where μ > 0 is the infinitesimal shear modulus, is the infinitesimal bulk modulus with the first Lamé constant, are dimensionless parameters, is the gradient of deformation, is the right stretch tensor and is the deviatoric part (the projection onto the traceless tensors) of the strain tensor log U. For small elastic strains, the energies reduce to first order to the classical quadratic Hencky energy which is known to be not rank-one convex. The main result in this paper is that in plane elastostatics the energies of the family are polyconvex for , extending a previous finding on its rank-one convexity. Our method uses a judicious application of Steigmann's polyconvexity criteria based on the representation of the energy in terms of the principal invariants of the stretch tensor U. These energies also satisfy suitable growth and coercivity conditions. We formulate the equilibrium equations, and we prove the existence of minimizers by the direct methods of the calculus of variations.
Külske, C
2003-01-01
We derive useful general concentration inequalities for functions of Gibbs fields in the uniqueness regime. We also consider expectations of random Gibbs measures that depend on an additional disorder field, and prove concentration w.r.t the disorder field. Both fields are assumed to be in the uniqueness regime, allowing in particular for non-independent disorder field. The modification of the bounds compared to the case of an independent field can be expressed in terms of constants that resemble the Dobrushin contraction coefficient, and are explicitly computable. On the basis of these inequalities, we obtain bounds on the deviation of a diffraction pattern created by random scatterers located on a general discrete point set in the Euclidean space, restricted to a finite volume. Here we also allow for thermal dislocations of the scatterers around their equilibrium positions. Extending recent results for independent scatterers, we give a universal upper bound on the probability of a deviation of the random sc...
Energy Technology Data Exchange (ETDEWEB)
Kayama, Koichiro; Hashimoto, Yasuhiko; Suzuki, Kenji; Matsuo, Hideki (Himeji Inst. of Tech., Hyogo (Japan) Fukushin Electric Co., Ltd., Hyogo (Japan))
1989-12-25
NiW {sub 2} B {sub 2} (M phase), existing in trinary Ni-W-B system, was measured in standard Gibbs free energy (GF) of formation in the temperature range from 1273K to 1423K by an electromotive force method (EMF) with use of solid oxide electrolyte. First, oxide phase in equilibrium with three-phase M-W-Ni solid solution region was confirmed to be B {sub 2} O {sub 3}. Binary Ni-W system solid solution in equilibrium with M phase and W phase is constant in composition with Ni-16.4mo1%W in the above temperature range. WO {sub 2} and WO {sub 2.72} were actually measured in GF. As Ni-W solid solution is in equilibrium with WO {sub 2} and WO {sub 2.72}, binary Ni-W system was measured in activity by the EMF, and Ni-16.4mo1%W solid solution was calculated in GF of mixing by use of the above measured GF of WO {sub 2} and WO {sub 2.72}. Finally with use of sample in M-W-Ni solid solution region, M phase was calculated in GF by the EMF. The result of those calculations were expressed with experimental formulas. 19 refs., 10 figs., 3 tabs.
A brief critique of the Adam-Gibbs entropy model
DEFF Research Database (Denmark)
Dyre, J. C.; Hecksher, Tina; Niss, Kristine
2009-01-01
This paper critically discusses the entropy model proposed by Adam and Gibbs in 1965 for the dramatic temperature dependence of glass-forming liquids' average relaxation time, which is one of the most influential models during the last four decades. We discuss the Adam-Gibbs model's theoretical...
Beyond Group: Multiple Person Tracking via Minimal Topology-Energy-Variation.
Gao, Shan; Ye, Qixiang; Xing, Junliang; Kuijper, Arjan; Han, Zhenjun; Jiao, Jianbin; Ji, Xiangyang
2017-12-01
Tracking multiple persons is a challenging task when persons move in groups and occlude each other. Existing group-based methods have extensively investigated how to make group division more accurately in a tracking-by-detection framework; however, few of them quantify the group dynamics from the perspective of targets' spatial topology or consider the group in a dynamic view. Inspired by the sociological properties of pedestrians, we propose a novel socio-topology model with a topology-energy function to factor the group dynamics of moving persons and groups. In this model, minimizing the topology-energy-variance in a two-level energy form is expected to produce smooth topology transitions, stable group tracking, and accurate target association. To search for the strong minimum in energy variation, we design the discrete group-tracklet jump moves embedded in the gradient descent method, which ensures that the moves reduce the energy variation of group and trajectory alternately in the varying topology dimension. Experimental results on both RGB and RGB-D data sets show the superiority of our proposed model for multiple person tracking in crowd scenes.
Minimizing the energy spread within a single bunch by shaping its charge distribution
International Nuclear Information System (INIS)
Loew, G.A.; Wang, J.
1984-06-01
When electrons or positrons in a bunch pass through the periodic structure of a linear accelerator, they leave behind them energy in the form of longitudinal wake fields. The longitudinal fields left behind by early particles in a bunch decrease the energy of later particles. For a linear collider, the energy spread introduced within the bunches by this beam loading effect must be minimized because it limits the degree to which the particles can be focused to a small spot due to chromatic effects in the final focus system. For example, for the SLC, the allowable energy spread is +-0.5%. It has been known for some time that partial compensation of the longitudinal wake field effects can be obtained for any bunch by placing it ahead of the accelerating crest (in space), thereby letting the positive rising sinusoidal field offset the negative beam loading field. The work presented in this report shows that it is possible to obtain complete compensation, i.e., to reduce the energy spread essentially to zero by properly shaping the longitudinal charge distribution of the bunch and by placing it at the correct position on the wave
Minimizing the magnetohydrodynamic potential energy for the current hole region in tokamaks
International Nuclear Information System (INIS)
Chu, M.S.; Parks, P.B.
2004-01-01
The current hole region in the tokamak has been observed to arise naturally during the development of internal transport barriers. The magnetohydrodynamic (MHD) potential energy in the current hole region is shown to be determined completely in terms of the displacements at the edge of the current hole. For modes with finite toroidal mode number n≠0, the minimized potential energy is the same as if the current hole region were a vacuum region. For modes with toroidal mode number n=0, the displacement is a superposition of three types of independent displacements: a vertical displacement or displacements that compress only the plasma, or the toroidal field uniformly. Thus for ideal MHD perturbations of plasma with a current hole, the plasma behaves as if it were bordered by an extra ''internal vacuum region.'' The relevance of the present work to computer simulations of plasma with a current hole region is also discussed
MINIMIZING THE MHD POTENTIAL ENERGY FOR THE CURRENT HOLE REGION IN TOKAMAKS
International Nuclear Information System (INIS)
CHU, M.S; PARKS, P.B
2004-01-01
The current hole region in the tokamak has been observed to arise naturally during the development of internal transport barriers. The magnetohydrodynamic (MHD) potential energy in the current hole region is shown to be determined completely in terms of the displacements at the edge of the current hole. For modes with finite toroidal mode number n ≠ 0, the minimized potential energy is the same as if the current hole region were a vacuum region. For modes with toroidal mode number n = 0, the displacement is a superposition of three types of independent displacements: a vertical displacement or displacements that compress only the plasma or the toroidal field uniformly. Thus for ideal MHD perturbations of plasma with a current hole, the plasma behaves as if it were bordered by an extra ''internal vacuum region''. The relevance of the present work to computer simulations of plasma with a current hole region is also discussed
Minimization of complementary energy to predict shear modulus of laminates with intralaminar cracks
International Nuclear Information System (INIS)
Giannadakis, K; Varna, J
2012-01-01
The most common damage mode and the one examined in this work is the formation of intralaminar cracks in layers of laminates. These cracks can occur when the composite structure is subjected to mechanical and/or thermal loading and eventually lead to degradation of thermo-elastic properties. In the present work, the shear modulus reduction due to cracking is studied. Mathematical models exist in literature for the simple case of cross-ply laminates. The in-plane shear modulus of a damaged laminate is only considered in a few studies. In the current work, the shear modulus reduction in cross-plies will be analysed based on the principle of minimization of complementary energy. Hashin investigated the in-plane shear modulus reduction of cross-ply laminates with cracks in inside 90-layer using this variational approach and assuming that the in-plane shear stress in layers does not depend on the thickness coordinate. In the present study, a more detailed and accurate approach for stress estimation is followed using shape functions for this dependence with parameters obtained by minimization. The results for complementary energy are then compared with the respective from literature and finally an expression for shear modulus degradation is derived.
Is the climate system an anticipatory system that minimizes free energy?
Rubin, Sergio; Crucifix, Michel
2017-04-01
All systems, whether they are alive or not are structured determined systems, i.e. their present states [x (t)] depends of past states [x (t - α)]. However it has been suggested [Rosen, 1985; Friston, 2013] that systems that contain life are capable of anticipation and active inference. The underlying principle is that state changes in living systems are best modelled as a function of past and future states [ x(t) = f (x (t - α), x(t), x (t + β)) ]. The reason for this is that living systems contain a predictive model of their ambiance on which they are active: they appear to model their ambiance to preserve their integrity and homeorhesis. We therefore formulate the following hypothesis: can the climate system be interpreted as an anticipatory system that minimizes free energy? Can its variability (catastrophe, bifurcation and/or tipping points) be interpreted in terms of active inference and anticipation failure? Here we present a mathematical formulation of the climate system as an anticipatory system that minimizes free energy and its possible implication in the future climate predictability. References Rosen, R. (1985). Anticipatory systems. In Anticipatory systems (pp. 313-370). Springer New York. Friston, K. (2013). Life as we know it. Journal of the Royal Society Interface, 10(86), 20130475.
Khan, Anwar; Ahmedy, Ismail; Anisi, Mohammad Hossein; Javaid, Nadeem; Ali, Ihsan; Khan, Nawsher; Alsaqer, Mohammed; Mahmood, Hasan
2018-01-09
Interference and energy holes formation in underwater wireless sensor networks (UWSNs) threaten the reliable delivery of data packets from a source to a destination. Interference also causes inefficient utilization of the limited battery power of the sensor nodes in that more power is consumed in the retransmission of the lost packets. Energy holes are dead nodes close to the surface of water, and their early death interrupts data delivery even when the network has live nodes. This paper proposes a localization-free interference and energy holes minimization (LF-IEHM) routing protocol for UWSNs. The proposed algorithm overcomes interference during data packet forwarding by defining a unique packet holding time for every sensor node. The energy holes formation is mitigated by a variable transmission range of the sensor nodes. As compared to the conventional routing protocols, the proposed protocol does not require the localization information of the sensor nodes, which is cumbersome and difficult to obtain, as nodes change their positions with water currents. Simulation results show superior performance of the proposed scheme in terms of packets received at the final destination and end-to-end delay.
Directory of Open Access Journals (Sweden)
Anwar Khan
2018-01-01
Full Text Available Interference and energy holes formation in underwater wireless sensor networks (UWSNs threaten the reliable delivery of data packets from a source to a destination. Interference also causes inefficient utilization of the limited battery power of the sensor nodes in that more power is consumed in the retransmission of the lost packets. Energy holes are dead nodes close to the surface of water, and their early death interrupts data delivery even when the network has live nodes. This paper proposes a localization-free interference and energy holes minimization (LF-IEHM routing protocol for UWSNs. The proposed algorithm overcomes interference during data packet forwarding by defining a unique packet holding time for every sensor node. The energy holes formation is mitigated by a variable transmission range of the sensor nodes. As compared to the conventional routing protocols, the proposed protocol does not require the localization information of the sensor nodes, which is cumbersome and difficult to obtain, as nodes change their positions with water currents. Simulation results show superior performance of the proposed scheme in terms of packets received at the final destination and end-to-end delay.
On minimal energy Hartree-Fock states for the 2DEG at fractional fillings
International Nuclear Information System (INIS)
Cabo Montes Oca, A. de.
1995-08-01
Approximate minimal energy solutions of the previously discussed general class of Hartree-Fock (HF) states of the 2DEG at 1/3 and 2/3 filling factors are determined. Their selfenergy spectrum is evaluated. Wannier states associated to the filled Bloch states are introduced in a lattice having three flux quanta per cell. They allow to rewrite approximately the ν = 1/3 HF Hamiltonian as sum of three independent tight-binding model Hamiltonians, one describing the dynamics in the band of occupied states and the other ones in the tow bands of excited states. The magnitude of the hopping integral indicates the enhanced role which should have the correlation energy in the present situation with respect to the case of the Yoshioka and Lee second order energy calculation for the lowest energy HF state. Finally, the discussion also suggests the Wannier function, which spreads an electron into a three quanta area, as a physical model for the composite fermion mean field one particle state. (author). 11 refs, 5 figs
Tang, Dunbing; Dai, Min
2015-09-01
The traditional production planning and scheduling problems consider performance indicators like time, cost and quality as optimization objectives in manufacturing processes. However, environmentally-friendly factors like energy consumption of production have not been completely taken into consideration. Against this background, this paper addresses an approach to modify a given schedule generated by a production planning and scheduling system in a job shop floor, where machine tools can work at different cutting speeds. It can adjust the cutting speeds of the operations while keeping the original assignment and processing sequence of operations of each job fixed in order to obtain energy savings. First, the proposed approach, based on a mixed integer programming mathematical model, changes the total idle time of the given schedule to minimize energy consumption in the job shop floor while accepting the optimal solution of the scheduling objective, makespan. Then, a genetic-simulated annealing algorithm is used to explore the optimal solution due to the fact that the problem is strongly NP-hard. Finally, the effectiveness of the approach is performed smalland large-size instances, respectively. The experimental results show that the approach can save 5%-10% of the average energy consumption while accepting the optimal solution of the makespan in small-size instances. In addition, the average maximum energy saving ratio can reach to 13%. And it can save approximately 1%-4% of the average energy consumption and approximately 2.4% of the average maximum energy while accepting the near-optimal solution of the makespan in large-size instances. The proposed research provides an interesting point to explore an energy-aware schedule optimization for a traditional production planning and scheduling problem.
International Nuclear Information System (INIS)
Schmidt, M.; Dinnebier, R.; Kalkhof, H.
2007-01-01
Diaryl azo pigments play an important role as yellow pigments for printing inks, with an annual pigment production of more than 50,000 t. The crystal structures of Pigment Yellow 12 (PY12), Pigment Yellow 13 (PY13), Pigment Yellow 14 (PY14), and Pigment Yellow 83 (PY83) were determined from X-ray powder data using lattice energy minimizations and subsequent Rietveld refinements. Details of the lattice energy minimization procedure and of the development of a torsion potential for the biphenyl fragment are given. The Rietveld refinements were carried out using rigid bodies, or constraints. It was also possible to refine all atomic positions individually without any constraint or restraint, even for PY12 having 44 independent non-hydrogen atoms per asymmetric unit. For PY14 (23 independent non-hydrogen atoms), additionally all atomic isotropic temperature factors could be refined individually. PY12 crystallized in a herringbone arrangement with twisted biaryl fragments. PY13 and PY14 formed a layer structure of planar molecules. PY83 showed a herringbone structure with planar molecules. According to quantum mechanical calculations, the twisting of the biaryl fragment results in a lower color strength of the pigments, whereas changes in the substitution pattern have almost no influence on the color strength of a single molecule. Hence, the experimentally observed lower color strength of PY12 in comparison with that of PY13 and PY83 can be explained as a pure packing effect. Further lattice energy calculations explained that the four investigated pigments crystallize in three different structures because these structures are the energetically most favorable ones for each compound. For example, for PY13, PY14, or PY83, a PY12-analogous crystal structure would lead to considerably poorer lattice energies and lower densities. In contrast, lattice energy calculations revealed that PY12 could adopt a PY13-type structure with only slightly poorer energy. This structure was
Evaluation of the accuracy of the free-energy-minimization method
International Nuclear Information System (INIS)
Najafabadi, R.; Srolovitz, D.J.
1995-01-01
We have made a detailed comparison between three competing methods for determining the free energies of solids and their defects: the thermodynamic integration of Monte Carlo (TIMC) data, the quasiharmonic (QH) model, and the free-energy-minimization (FEM) method. The accuracy of these methods decreases from the TIMC to QH to FEM method, while the computational efficiency improves in that order. All three methods yield perfect crystal lattice parameters and free energies at finite temperatures which are in good agreement for three different Cu interatomic potentials [embedded atom method (EAM), Morse and Lennard-Jones]. The FEM error (relative to the TIMC) in the (001) surface free energy and in the vacancy formation energy were found to be much larger for the EAM potential than for the other two potentials. Part of the errors in the FEM determination of the free energies are associated with anharmonicities in the interatomic potentials, with the remainder attributed to decoupling of the atomic vibrations. The anharmonicity of the EAM potential was found to be unphysically large compared with experimental vacancy formation entropy determinations. Based upon these results, we show that the FEM method provides a reasonable compromise between accuracy and computational demands. However, the accuracy of this approach is sensitive to the choice of interatomic potential and the nature of the defect to which it is being applied. The accuracy of the FEM is best in high-symmetry environments (perfect crystal, high-symmetry defects, etc.) and when used to describe materials where the anharmonicity is not too large
Psychoanalytic Interpretation of Blueberries by Susan Gibb
Directory of Open Access Journals (Sweden)
Maya Zalbidea Paniagua
2014-06-01
Full Text Available Blueberries (2009 by Susan Gibb, published in the ELO (Electronic Literature Organization, invites the reader to travel inside the protagonist’s mind to discover real and imaginary experiences examining notions of gender, sex, body and identity of a traumatised woman. This article explores the verbal and visual modes in this digital short fiction following semiotic patterns as well as interpreting the psychological states that are expressed through poetical and technological components. A comparative study of the consequences of trauma in the protagonist will be developed including psychoanalytic theories by Sigmund Freud, Jacques Lacan and the feminist psychoanalysts: Melanie Klein and Bracha Ettinger. The reactions of the protagonist will be studied: loss of reality, hallucinations and Electra Complex, as well as the rise of defence mechanisms and her use of the artistic creativity as a healing therapy. The interactivity of the hypermedia, multiple paths and endings will be analyzed as a literary strategy that increases the reader’s capacity of empathizing with the speaker.
International Nuclear Information System (INIS)
Falconer, K.L.; Lane, T.C.
1991-01-01
A Waste Minimization Program Plan for the U.S. Department of Energy's (DOE) Naval Petroleum Reserve No. 3 (NPR-3) was prepared in response to DOE Order 5400.1, open-quotes General Environmental Protection Program close-quote The NPR-3 Waste Minimization Program Plan encompasses all ongoing operations at the Naval Petroleum Reserve and is consistent with the principles set forth in the mission statement for NPR-3. The mission of the NPR-3 is to apply project management, engineering and scientific capabilities to produce oil and gas from subsurface zones at the maximum efficiency rate for the United States Government. NPR-3 generates more than 60 discrete waste streams, many of significant volume. Most of these waste streams are categorized as wastes from the exploration, development and production of oil and gas and, as such, are exempt from Subtitle C of RCRA as indicated in the regulatory determination published in the Federal Register on July 6, 1988. However, because so many of these waste streams contain hazardous substances and because of an increasingly more restrictive regulatory environment, in 1990 an overall effort was made to characterize all waste streams produced and institute the best waste management practice economically practical to reduce the volume and toxicity of the waste generated
Gibbs perturbations of a two-dimensional gauge field
International Nuclear Information System (INIS)
Petrova, E.N.
1981-01-01
Small Gibbs perturbations of random fields have been investigated up to now for a few initial fields only. Among them there are independent fields, Gaussian fields and some others. The possibility for the investigation of Gibbs modifications of a random field depends essentially on the existence of good estimates for semiinvariants of this field. This is the reason why the class of random fields for which the investigation of Gibbs perturbations with arbitrary potential of bounded support is possible is rather small. The author takes as initial a well-known model: a two-dimensional gauge field. (Auth.)
Energy consumption during simulated minimal access surgery with and without using an armrest.
Jafri, Mansoor; Brown, Stuart; Arnold, Graham; Abboud, Rami; Wang, Weijie
2013-03-01
Minimal access surgery (MAS) can be a lengthy procedure when compared to open surgery and therefore surgeon fatigue becomes an important issue and surgeons may expose themselves to chronic injuries and making errors. There have been few studies on this topic and they have used only questionnaires and electromyography rather than direct measurement of energy expenditure (EE). The aim of this study was to investigate whether the use of an armrest could reduce the EE of surgeons during MAS. Sixteen surgeons performed simulated MAS with and without using an armrest. They were required to perform the time-consuming task of using scissors to cut a rubber glove through its top layer in a triangular fashion with the help of a laparoscopic camera. Energy consumptions were measured using the Oxycon Mobile system during all the procedures. Error rate and duration time for simulated surgery were recorded. After performing the simulated surgery, subjects scored how comfortable they felt using the armrest. It was found that O(2) uptake (VO(2)) was 5 % less when surgeons used the armrest. The error rate when performing the procedure with the armrest was 35 % compared with 42.29 % without the armrest. Additionally, comfort levels with the armrest were higher than without the armrest. 75 % of surgeons indicated a preference for using the armrest during the simulated surgery. The armrest provides support for surgeons and cuts energy consumption during simulated MAS.
Coal consumption minimizing by increasing thermal energy efficiency at ROMAG-PROD Heavy Water Plant
International Nuclear Information System (INIS)
Preda, Marius Cristian
2006-01-01
ROMAG-PROD Heavy Water Plant is a large thermal energy consumer using almost all the steam output from ROMAG-TERMO Power Plant - the steam cost weight in the total heavy water price is about 40%. The steam consumption minimizing by modernization of isotopic exchange facilities and engineering development in ROMAG-PROD Heavy Water Plant results in an corresponding decrease of coal amount burned at ROMAG-TERMO boilers. This decrease could be achieved mainly by the followings ways: - Facility wrappings integrity; - High performance heat exchangers; - Refurbished heat insulations; - Modified condenser-collecting pipeline routes; - High performance steam traps; - Heat electric wire. When coal is burned in Power Plant burners to obtain thermal energy, toxic emissions results in flue gases, such as: - CO 2 and NO x with impact on climate warming; - SO 2 which results in ozone layer thinning effect and in acid rain falls. From the value of steam output per burned coal: 1 GCal steam = 1.41 tone steam = 0.86 thermal MW = 1.1911 tones burned coal (lignite), it is obvious that by decreasing the thermal energy consumption provided for ROMAG PROD, a coal amount decrease is estimated at about 45 t/h, or about 394,200 t/year coal, which means about 10% of the current coal consumption at ROMAG-TERMO PP. At the same time, by reducing the burned coal amount, an yearly decrease in emissions into air to about 400,000 tones CO 2 is expected
Potential pollution prevention and waste minimization for Department of Energy operations
International Nuclear Information System (INIS)
Griffin, J.; Ischay, C.; Kennicott, M.; Pemberton, S.; Tull, D.
1995-10-01
With the tightening of budgets and limited resources, it is important to ensure operations are carried out in a cost-effective and productive manner. Implementing an effective Pollution Prevention strategy can help to reduce the costs of waste management and prevent harmful releases to the environment. This document provides an estimate of the Department of Energy's waste reduction potential from the implementation of Pollution Prevention opportunities. A team of Waste Minimization and Pollution Prevention professionals was formed to collect the data and make the estimates. The report includes a list of specific reduction opportunities for various waste generating operations and waste types. A generic set of recommendations to achieve these reduction opportunities is also provided as well as a general discussion of the approach and assumptions made for each waste generating operation
Is spontaneous breaking of R-parity feasible in minimal low-energy supergravity
International Nuclear Information System (INIS)
Gato, B.; Leon, J.; Perez-Mercader, J.; Quiros, M.
1985-01-01
Spontaneous violation of lepton number without breaking Lorentz invariance can, in principle, be incorporated in models with softly broken supersymmetry. We study the situation for minimal low-energy supergravity models coming from a GUT (hence not having hierarchy destabilizing light singlets) and where the SU(2)xU(1) breaking is radiative. It is found that for this type of model, R-parity breaking requires either too heavy a top quark for a realistic superpartner spectrum or too light a superpartner spectrum for a realistic top quark, making the spontaneous violation of lepton number in the third generation incompatible with present experimental data. We do not discard the possibility of having it in a fourth, heavier, generation. (orig.)
Non-minimal derivative coupling scalar field and bulk viscous dark energy
Energy Technology Data Exchange (ETDEWEB)
Mostaghel, Behrang [Shahid Beheshti University, Department of Physics, Tehran (Iran, Islamic Republic of); Moshafi, Hossein [Institute for Advanced Studies in Basic Sciences, Department of Physics, Zanjan (Iran, Islamic Republic of); Movahed, S.M.S. [Shahid Beheshti University, Department of Physics, Tehran (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of)
2017-08-15
Inspired by thermodynamical dissipative phenomena, we consider bulk viscosity for dark fluid in a spatially flat two-component Universe. Our viscous dark energy model represents phantom-crossing which avoids big-rip singularity. We propose a non-minimal derivative coupling scalar field with zero potential leading to accelerated expansion of the Universe in the framework of bulk viscous dark energy model. In this approach, the coupling constant, κ, is related to viscosity coefficient, γ, and the present dark energy density, Ω{sub DE}{sup 0}. This coupling is bounded as κ element of [-1/9H{sub 0}{sup 2}(1 - Ω{sub DE}{sup 0}), 0]. We implement recent observational data sets including a joint light-curve analysis (JLA) for SNIa, gamma ray bursts (GRBs) for most luminous astrophysical objects at high redshifts, baryon acoustic oscillations (BAO) from different surveys, Hubble parameter from HST project, Planck CMB power spectrum and lensing to constrain model free parameters. The joint analysis of JLA + GRBs + BAO + HST shows that Ω{sub DE}{sup 0} = 0.696 ± 0.010, γ = 0.1404 ± 0.0014 and H{sub 0} = 68.1 ± 1.3. Planck TT observation provides γ = 0.32{sup +0.31}{sub -0.26} in the 68% confidence limit for the viscosity coefficient. The cosmographic distance ratio indicates that current observed data prefer to increase bulk viscosity. The competition between phantom and quintessence behavior of the viscous dark energy model can accommodate cosmological old objects reported as a sign of age crisis in the ΛCDM model. Finally, tension in the Hubble parameter is alleviated in this model. (orig.)
Reflections on Gibbs: From Critical Phenomena to the Amistad
Kadanoff, Leo P.
2003-03-01
J. Willard Gibbs, the younger was the first American theorist. He was one of the inventors of statistical physics. His introduction and development of the concepts of phase space, phase transitions, and thermodynamic surfaces was remarkably correct and elegant. These three concepts form the basis of different but related areas of physics. The connection among these areas has been a subject of deep reflection from Gibbs' time to our own. I shall talk about these connections by using concepts suggested by the work of Michael Berry and explicitly put forward by the philosopher Robert Batterman. This viewpoint relates theory-connection to the applied mathematics concepts of asymptotic analysis and singular perturbations. J. Willard Gibbs, the younger, had all his achievements concentrated in science. His father, also J. Willard Gibbs, also a Professor at Yale, had one great achievement that remains unmatched in our day. I shall describe it.
Boltzmann, Gibbs and Darwin-Fowler approaches in parastatistics
International Nuclear Information System (INIS)
Ponczek, R.L.; Yan, C.C.
1976-01-01
Derivations of the equilibrium values of occupation numbers are made using three approaches, namely, the Boltzmann 'elementary' one, the ensemble method of Gibbs, and that of Darwin and Fowler as well [pt
Liu, Gang; Bao, Jie
2017-12-01
Energy consumption and wastewater generation in cellulosic ethanol production are among the determinant factors on overall cost and technology penetration into fuel ethanol industry. This study analyzed the energy consumption and wastewater generation by the new biorefining process technology, dry acid pretreatment and biodetoxification (DryPB), as well as by the current mainstream technologies. DryPB minimizes the steam consumption to 8.63GJ and wastewater generation to 7.71tons in the core steps of biorefining process for production of one metric ton of ethanol, close to 7.83GJ and 8.33tons in corn ethanol production, respectively. The relatively higher electricity consumption is compensated by large electricity surplus from lignin residue combustion. The minimum ethanol selling price (MESP) by DryPB is below $2/gal and falls into the range of corn ethanol production cost. The work indicates that the technical and economical gap between cellulosic ethanol and corn ethanol has been almost filled up. Copyright © 2017 Elsevier Ltd. All rights reserved.
Gibbs phenomenon for dispersive PDEs on the line
Biondini, Gino; Trogdon, Thomas
2014-01-01
We investigate the Cauchy problem for linear, constant-coefficient evolution PDEs on the real line with discontinuous initial conditions (ICs) in the small-time limit. The small-time behavior of the solution near discontinuities is expressed in terms of universal, computable special functions. We show that the leading-order behavior of the solution of dispersive PDEs near a discontinuity of the ICs is characterized by Gibbs-type oscillations and gives exactly the Wilbraham-Gibbs constant.
de Carvalho, Alberito Rodrigo; Andrade, Alexandro; Peyré-Tartaruga, Leonardo Alexandre
2015-01-01
One goal of the locomotion is to move the body in the space at the most economical way possible. However, little is known about the mechanical and energetic aspects of locomotion that are affected by low back pain. And in case of occurring some damage, little is known about how the mechanical and energetic characteristics of the locomotion are manifested in functional activities, especially with respect to the energy-minimizer mechanisms during locomotion. This study aimed: a) to describe the main energy-minimizer mechanisms of locomotion; b) to check if there are signs of damage on the mechanical and energetic characteristics of the locomotion due to chronic low back pain (CLBP) which may endanger the energy-minimizer mechanisms. This study is characterized as a narrative literature review. The main theory that explains the minimization of energy expenditure during the locomotion is the inverted pendulum mechanism, by which the energy-minimizer mechanism converts kinetic energy into potential energy of the center of mass and vice-versa during the step. This mechanism is strongly influenced by spatio-temporal gait (locomotion) parameters such as step length and preferred walking speed, which, in turn, may be severely altered in patients with chronic low back pain. However, much remains to be understood about the effects of chronic low back pain on the individual's ability to practice an economic locomotion, because functional impairment may compromise the mechanical and energetic characteristics of this type of gait, making it more costly. Thus, there are indications that such changes may compromise the functional energy-minimizer mechanisms. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.
International Nuclear Information System (INIS)
De Kleine, Robert D.; Keoleian, Gregory A.; Kelly, Jarod C.
2011-01-01
A life cycle optimization of the replacement of residential central air conditioners (CACs) was conducted in order to identify replacement schedules that minimized three separate objectives: life cycle energy consumption, greenhouse gas (GHG) emissions, and consumer cost. The analysis was conducted for the time period of 1985-2025 for Ann Arbor, MI and San Antonio, TX. Using annual sales-weighted efficiencies of residential CAC equipment, the tradeoff between potential operational savings and the burdens of producing new, more efficient equipment was evaluated. The optimal replacement schedule for each objective was identified for each location and service scenario. In general, minimizing energy consumption required frequent replacement (4-12 replacements), minimizing GHG required fewer replacements (2-5 replacements), and minimizing cost required the fewest replacements (1-3 replacements) over the time horizon. Scenario analysis of different federal efficiency standards, regional standards, and Energy Star purchases were conducted to quantify each policy's impact. For example, a 16 SEER regional standard in Texas was shown to either reduce primary energy consumption 13%, GHGs emissions by 11%, or cost by 6-7% when performing optimal replacement of CACs from 2005 or before. The results also indicate that proper servicing should be a higher priority than optimal replacement to minimize environmental burdens. - Highlights: → Optimal replacement schedules for residential central air conditioners were found. → Minimizing energy required more frequent replacement than minimizing consumer cost. → Significant variation in optimal replacement was observed for Michigan and Texas. → Rebates for altering replacement patterns are not cost effective for GHG abatement. → Maintenance levels were significant in determining the energy and GHG impacts.
Directory of Open Access Journals (Sweden)
Cobaugh Christian W
2004-08-01
Full Text Available Abstract Background A detailed understanding of an RNA's correct secondary and tertiary structure is crucial to understanding its function and mechanism in the cell. Free energy minimization with energy parameters based on the nearest-neighbor model and comparative analysis are the primary methods for predicting an RNA's secondary structure from its sequence. Version 3.1 of Mfold has been available since 1999. This version contains an expanded sequence dependence of energy parameters and the ability to incorporate coaxial stacking into free energy calculations. We test Mfold 3.1 by performing the largest and most phylogenetically diverse comparison of rRNA and tRNA structures predicted by comparative analysis and Mfold, and we use the results of our tests on 16S and 23S rRNA sequences to assess the improvement between Mfold 2.3 and Mfold 3.1. Results The average prediction accuracy for a 16S or 23S rRNA sequence with Mfold 3.1 is 41%, while the prediction accuracies for the majority of 16S and 23S rRNA structures tested are between 20% and 60%, with some having less than 20% prediction accuracy. The average prediction accuracy was 71% for 5S rRNA and 69% for tRNA. The majority of the 5S rRNA and tRNA sequences have prediction accuracies greater than 60%. The prediction accuracy of 16S rRNA base-pairs decreases exponentially as the number of nucleotides intervening between the 5' and 3' halves of the base-pair increases. Conclusion Our analysis indicates that the current set of nearest-neighbor energy parameters in conjunction with the Mfold folding algorithm are unable to consistently and reliably predict an RNA's correct secondary structure. For 16S or 23S rRNA structure prediction, Mfold 3.1 offers little improvement over Mfold 2.3. However, the nearest-neighbor energy parameters do work well for shorter RNA sequences such as tRNA or 5S rRNA, or for larger rRNAs when the contact distance between the base-pairs is less than 100 nucleotides.
Wang, Li; Yang, Xiaonan; Wang, Quandai; Yang, Zhiqiang; Duan, Hui; Lu, Bingheng
2017-07-01
The construction of stable hydrophobic surfaces has increasingly gained attention owing to its wide range of potential applications. However, these surfaces may become wet and lose their slip effect owing to insufficient hydrophobic stability. Pillars with a mushroom-shaped tip are believed to enhance hydrophobicity stability. This work presents a facile method of manufacturing mushroom-shaped structures, where, compared with the previously used method, the modulation of the cap thickness, cap diameter, and stem height of the structures is more convenient. The effects of the development time on the cap diameter and overhanging angle are investigated and well-defined mushroom-shaped structures are demonstrated. The effect of the microstructure geometry on the contact state of a droplet is predicted by taking an energy minimization approach and is experimentally validated with nonvolatile ultraviolet-curable polymer with a low surface tension by inspecting the profiles of liquid-vapor interface deformation and tracking the trace of the receding contact line after exposure to ultraviolet light. Theoretical and experimental results show that, compared with regular pillar arrays having a vertical sidewall, the mushroom-like structures can effectively enhance hydrophobic stability. The proposed manufacturing method will be useful for fabricating robust hydrophobic surfaces in a cost-effective and convenient manner.
Suamir, I. N.; Sukadana, I. B. P.; Arsana, M. E.
2018-01-01
One energy-saving technology that starts gaining attractive for hotel industry application in Indonesia is the utilization of waste heat of a central air conditioning system to heat water for domestic hot water supply system. Implementing the technology for such application at a hotel was found that hot water capacity generated from the heat recovery system could satisfy domestic hot water demand of the hotel. The gas boilers installed in order to back up the system have never been used. The hot water supply, however, was found to be instable with hot water supply temperature fluctuated ranging from 45 °C to 62 °C. The temperature fluctuations reaches 17 °C, which is considered instable and can reduce hot water usage comfort level. This research is aimed to optimize the thermal energy storage in order to minimize the temperature instability of heat recovery hot water supply system. The research is a case study approach based on cooling and hot water demands of a hotel in Jakarta-Indonesia that has applied water cooled chillers with heat recovery systems. The hotel operation with 329 guest rooms and 8 function rooms showed that hot water production in the heat recovery system completed with 5 m3 thermal energy storage (TES) could not hold the hot water supply temperature constantly. The variations of the cooling demand and hot water demands day by day were identified. It was found that there was significant mismatched of available time (hours) between cooling demand which is directly correlated to the hot water production from the heat recovery system and hot water usage. The available TES system could not store heat rejected from the condenser of the chiller during cooling demand peak time between 14.00 and 18.00 hours. The extra heat from the heat recovery system consequently increases the temperature of hot water up to 62 °C. It is about 12 K above 50 °C the requirement hot water temperature of the hotel. In contrast, the TES could not deliver proper
Algunas Precisiones en torno a las funciones termodinámicas energía libre de Gibbs
Solaz Portolés, Joan Josep; Quílez Pardo, Juan
2001-01-01
The aim of this study is to elucidate some didactic misundertandings related with the use and the appli cability of the delta functions ∆G, ∆rG and ∆rG0, which derive from the thermodynamic potential Gibbs Free Energy, G.
Effects of thermal fluctuations on non-minimal regular magnetic black hole
International Nuclear Information System (INIS)
Jawad, Abdul; Shahzad, M.U.
2017-01-01
We analyze the effects of thermal fluctuations on a regular black hole (RBH) of the non-minimal Einstein-Yang-Mill theory with gauge field of magnetic Wu-Yang type and a cosmological constant. We consider the logarithmic corrected entropy in order to analyze the thermal fluctuations corresponding to non-minimal RBH thermodynamics. In this scenario, we develop various important thermodynamical quantities, such as entropy, pressure, specific heats, Gibb's free energy and Helmholtz free energy. We investigate the first law of thermodynamics in the presence of logarithmic corrected entropy and non-minimal RBH. We also discuss the stability of this RBH using various frameworks such as the γ factor (the ratio of heat capacities), phase transition, grand canonical ensemble and canonical ensemble. It is observed that the non-minimal RBH becomes globally and locally more stable if we increase the value of the cosmological constant. (orig.)
Effects of thermal fluctuations on non-minimal regular magnetic black hole
Energy Technology Data Exchange (ETDEWEB)
Jawad, Abdul [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); Shahzad, M.U. [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); University of Central Punjab, CAMS, UCP Business School, Lahore (Pakistan)
2017-05-15
We analyze the effects of thermal fluctuations on a regular black hole (RBH) of the non-minimal Einstein-Yang-Mill theory with gauge field of magnetic Wu-Yang type and a cosmological constant. We consider the logarithmic corrected entropy in order to analyze the thermal fluctuations corresponding to non-minimal RBH thermodynamics. In this scenario, we develop various important thermodynamical quantities, such as entropy, pressure, specific heats, Gibb's free energy and Helmholtz free energy. We investigate the first law of thermodynamics in the presence of logarithmic corrected entropy and non-minimal RBH. We also discuss the stability of this RBH using various frameworks such as the γ factor (the ratio of heat capacities), phase transition, grand canonical ensemble and canonical ensemble. It is observed that the non-minimal RBH becomes globally and locally more stable if we increase the value of the cosmological constant. (orig.)
Self-organization, free energy minimization, and optimal grip on a field of affordances
Directory of Open Access Journals (Sweden)
Jelle eBruineberg
2014-08-01
Full Text Available In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology, dynamical systems theory, and neurodynamics. We suggest that the main task of Radical Embodied Cognitive Neuroscience is to investigate the phenomenon of skilled intentionality from the perspective of the self-organization of the brain-body-environment system, while doing justice to the phenomenology of skilled action. In previous work, we have characterized skilled intentionality as the organism’s tendency towards an optimal grip on multiple relevant affordances simultaneously. Affordances are possibilities for action provided by the environment. In the first part of this paper, we introduce the notion of skilled intentionality and the phenomenon of responsiveness to a field of relevant affordances. Second, we use Friston’s work on neurodynamics, but embed a very minimal version of his Free Energy Principle in the ecological niche of the animal. Thus amended, this principle is helpful for understanding the embeddedness of neurodynamics within the dynamics of the brain-body-environment system. Next, we show how we can use this adjusted principle to understand the neurodynamics of selective openness to the environment: interacting action-readiness patterns at multiple timescales contribute to the organism’s selective openness to relevant affordances. In the final part of the paper, we emphasize the important role of metastable dynamics in both the brain and the brain-body-environment system for adequate affordance-responsiveness. We exemplify our integrative approach by presenting research on the impact of Deep Brain Stimulation on affordance responsiveness of OCD patients.
Self-organization, free energy minimization, and optimal grip on a field of affordances.
Bruineberg, Jelle; Rietveld, Erik
2014-01-01
In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology, dynamical systems theory, and neurodynamics. We suggest that the main task of Radical Embodied Cognitive Neuroscience is to investigate the phenomenon of skilled intentionality from the perspective of the self-organization of the brain-body-environment system, while doing justice to the phenomenology of skilled action. In previous work, we have characterized skilled intentionality as the organism's tendency toward an optimal grip on multiple relevant affordances simultaneously. Affordances are possibilities for action provided by the environment. In the first part of this paper, we introduce the notion of skilled intentionality and the phenomenon of responsiveness to a field of relevant affordances. Second, we use Friston's work on neurodynamics, but embed a very minimal version of his Free Energy Principle in the ecological niche of the animal. Thus amended, this principle is helpful for understanding the embeddedness of neurodynamics within the dynamics of the system "brain-body-landscape of affordances." Next, we show how we can use this adjusted principle to understand the neurodynamics of selective openness to the environment: interacting action-readiness patterns at multiple timescales contribute to the organism's selective openness to relevant affordances. In the final part of the paper, we emphasize the important role of metastable dynamics in both the brain and the brain-body-environment system for adequate affordance-responsiveness. We exemplify our integrative approach by presenting research on the impact of Deep Brain Stimulation on affordance responsiveness of OCD patients.
Resmini, Ronald G.; Graver, William R.; Kappus, Mary E.; Anderson, Mark E.
1996-11-01
Constrained energy minimization (CEM) has been applied to the mapping of the quantitative areal distribution of the mineral alunite in an approximately 1.8 km2 area of the Cuprite mining district, Nevada. CEM is a powerful technique for rapid quantitative mineral mapping which requires only the spectrum of the mineral to be mapped. A priori knowledge of background spectral signatures is not required. Our investigation applies CEM to calibrated radiance data converted to apparent reflectance (AR) and to single scattering albedo (SSA) spectra. The radiance data were acquired by the 210 channel, 0.4 micrometers to 2.5 micrometers airborne Hyperspectral Digital Imagery Collection Experiment sensor. CEM applied to AR spectra assumes linear mixing of the spectra of the materials exposed at the surface. This assumption is likely invalid as surface materials, which are often mixtures of particulates of different substances, are more properly modeled as intimate mixtures and thus spectral mixing analyses must take account of nonlinear effects. One technique for approximating nonlinear mixing requires the conversion of AR spectra to SSA spectra. The results of CEM applied to SSA spectra are compared to those of CEM applied to AR spectra. The occurrence of alunite is similar though not identical to mineral maps produced with both the SSA and AR spectra. Alunite is slightly more widespread based on processing with the SSA spectra. Further, fractional abundances derived from the SSA spectra are, in general, higher than those derived from AR spectra. Implications for the interpretation of quantitative mineral mapping with hyperspectral remote sensing data are discussed.
Time-dependent generalized Gibbs ensembles in open quantum systems
Lange, Florian; Lenarčič, Zala; Rosch, Achim
2018-04-01
Generalized Gibbs ensembles have been used as powerful tools to describe the steady state of integrable many-particle quantum systems after a sudden change of the Hamiltonian. Here, we demonstrate numerically that they can be used for a much broader class of problems. We consider integrable systems in the presence of weak perturbations which break both integrability and drive the system to a state far from equilibrium. Under these conditions, we show that the steady state and the time evolution on long timescales can be accurately described by a (truncated) generalized Gibbs ensemble with time-dependent Lagrange parameters, determined from simple rate equations. We compare the numerically exact time evolutions of density matrices for small systems with a theory based on block-diagonal density matrices (diagonal ensemble) and a time-dependent generalized Gibbs ensemble containing only a small number of approximately conserved quantities, using the one-dimensional Heisenberg model with perturbations described by Lindblad operators as an example.
Holistic virtual machine scheduling in cloud datacenters towards minimizing total energy
Li, Xiang; Garraghan, Peter; Jiang, Xiaohong; Wu, Zhaohui; Xu, Jie
2018-01-01
Energy consumed by Cloud datacenters has dramatically increased, driven by rapid uptake of applications and services globally provisioned through virtualization. By applying energy-aware virtual machine scheduling, Cloud providers are able to achieve enhanced energy efficiency and reduced operation cost. Energy consumption of datacenters consists of computing energy and cooling energy. However, due to the complexity of energy and thermal modeling of realistic Cloud datacenter operation, tradi...
A logistic regression estimating function for spatial Gibbs point processes
DEFF Research Database (Denmark)
Baddeley, Adrian; Coeurjolly, Jean-François; Rubak, Ege
We propose a computationally efficient logistic regression estimating function for spatial Gibbs point processes. The sample points for the logistic regression consist of the observed point pattern together with a random pattern of dummy points. The estimating function is closely related to the p......We propose a computationally efficient logistic regression estimating function for spatial Gibbs point processes. The sample points for the logistic regression consist of the observed point pattern together with a random pattern of dummy points. The estimating function is closely related...
Sid, S; Volant, A; Lesage, G; Heran, M
2017-11-01
Energy consumption and sludge production minimization represent rising challenges for wastewater treatment plants (WWTPs). The goal of this study is to investigate how energy is consumed throughout the whole plant and how operating conditions affect this energy demand. A WWTP based on the activated sludge process was selected as a case study. Simulations were performed using a pre-compiled model implemented in GPS-X simulation software. Model validation was carried out by comparing experimental and modeling data of the dynamic behavior of the mixed liquor suspended solids (MLSS) concentration and nitrogen compounds concentration, energy consumption for aeration, mixing and sludge treatment and annual sludge production over a three year exercise. In this plant, the energy required for bioreactor aeration was calculated at approximately 44% of the total energy demand. A cost optimization strategy was applied by varying the MLSS concentrations (from 1 to 8 gTSS/L) while recording energy consumption, sludge production and effluent quality. An increase of MLSS led to an increase of the oxygen requirement for biomass aeration, but it also reduced total sludge production. Results permit identification of a key MLSS concentration allowing identification of the best compromise between levels of treatment required, biological energy demand and sludge production while minimizing the overall costs.
Radio frequency energy for non-invasive and minimally invasive skin tightening.
Mulholland, R Stephen
2011-07-01
This article reviews the non-invasive and minimally invasive options for skin tightening, focusing on peer-reviewed articles and presentations and those technologies with the most proven or promising RF non-excisional skin-tightening results for excisional surgeons. RF has been the mainstay of non-invasive skin tightening and has emerged as the "cutting edge" technology in the minimally invasive skin-tightening field. Because these RF skin-tightening technologies are capital equipment purchases with a significant cost associated, this article also discusses some business issues and models that have proven to work in the plastic surgeon's office for non-invasive and minimally invasive skin-tightening technologies. Copyright © 2011 Elsevier Inc. All rights reserved.
Virial theorem and Gibbs thermodynamic potential for Coulomb systems
International Nuclear Information System (INIS)
Bobrov, V. B.; Trigger, S. A.
2014-01-01
Using the grand canonical ensemble and the virial theorem, we show that the Gibbs thermodynamic potential of the non-relativistic system of charged particles is uniquely defined by single-particle Green functions of electrons and nuclei. This result is valid beyond the perturbation theory with respect to the interparticle interaction
Virial theorem and Gibbs thermodynamic potential for Coulomb systems
Bobrov, V. B.; Trigger, S. A.
2013-01-01
Using the grand canonical ensemble and the virial theorem, we show that the Gibbs thermodynamic potential of the non-relativistic system of charged particles is uniquely defined by single-particle Green functions of electrons and nuclei. This result is valid beyond the perturbation theory with respect to the interparticle interaction.
Inverse Gaussian model for small area estimation via Gibbs sampling
African Journals Online (AJOL)
We present a Bayesian method for estimating small area parameters under an inverse Gaussian model. The method is extended to estimate small area parameters for finite populations. The Gibbs sampler is proposed as a mechanism for implementing the Bayesian paradigm. We illustrate the method by application to ...
Exploring Fourier Series and Gibbs Phenomenon Using Mathematica
Ghosh, Jonaki B.
2011-01-01
This article describes a laboratory module on Fourier series and Gibbs phenomenon which was undertaken by 32 Year 12 students. It shows how the use of CAS played the role of an "amplifier" by making higher level mathematical concepts accessible to students of year 12. Using Mathematica students were able to visualise Fourier series of…
Thermodynamic fluctuations within the Gibbs and Einstein approaches
International Nuclear Information System (INIS)
Rudoi, Yurii G; Sukhanov, Alexander D
2000-01-01
A comparative analysis of the descriptions of fluctuations in statistical mechanics (the Gibbs approach) and in statistical thermodynamics (the Einstein approach) is given. On this basis solutions are obtained for the Gibbs and Einstein problems that arise in pressure fluctuation calculations for a spatially limited equilibrium (or slightly nonequilibrium) macroscopic system. A modern formulation of the Gibbs approach which allows one to calculate equilibrium pressure fluctuations without making any additional assumptions is presented; to this end the generalized Bogolyubov - Zubarev and Hellmann - Feynman theorems are proved for the classical and quantum descriptions of a macrosystem. A statistical version of the Einstein approach is developed which shows a fundamental difference in pressure fluctuation results obtained within the context of two approaches. Both the 'genetic' relation between the Gibbs and Einstein approaches and the conceptual distinction between their physical grounds are demonstrated. To illustrate the results, which are valid for any thermodynamic system, an ideal nondegenerate gas of microparticles is considered, both classically and quantum mechanically. Based on the results obtained, the correspondence between the micro- and macroscopic descriptions is considered and the prospects of statistical thermodynamics are discussed. (reviews of topical problems)
Sia, Sheau Fung; Zhao, Xihai; Li, Rui; Zhang, Yu; Chong, Winston; He, Le; Chen, Yu
2016-11-01
Internal carotid artery stenosis requires an accurate risk assessment for the prevention of stroke. Although the internal carotid artery area stenosis ratio at the common carotid artery bifurcation can be used as one of the diagnostic methods of internal carotid artery stenosis, the accuracy of results would still depend on the measurement techniques. The purpose of this study is to propose a novel method to estimate the effect of internal carotid artery stenosis on the blood flow based on the concept of minimization of energy loss. Eight internal carotid arteries from different medical centers were diagnosed as stenosed internal carotid arteries, as plaques were found at different locations on the vessel. A computational fluid dynamics solver was developed based on an open-source code (OpenFOAM) to test the flow ratio and energy loss of those stenosed internal carotid arteries. For comparison, a healthy internal carotid artery and an idealized internal carotid artery model have also been tested and compared with stenosed internal carotid artery in terms of flow ratio and energy loss. We found that at a given common carotid artery bifurcation, there must be a certain flow distribution in the internal carotid artery and external carotid artery, for which the total energy loss at the bifurcation is at a minimum; for a given common carotid artery flow rate, an irregular shaped plaque at the bifurcation constantly resulted in a large value of minimization of energy loss. Thus, minimization of energy loss can be used as an indicator for the estimation of internal carotid artery stenosis.
Gibbs energy formation of Sr5Nb4O15
International Nuclear Information System (INIS)
Samui, Pradeep; Padhi, Anyuna; Agarwal, Renu; Kulkarni, S.G.
2012-01-01
Ternary oxides of strontium and niobium may form as fission product compounds in an operating nuclear reactor with oxide fuels under certain oxygen potential. Evaluations of thermodynamic stability of these ternary oxides are therefore important for assessment of fission product interactions. Furthermore, thermodynamic data of these oxides are also of relevance because of computation of phase diagram and phase stability of pseudo-ternary systems BaO-SrO-Nb 2 O 5 , SrO-Nb 2 O 5 -TaO 5 etc. in which some of the compounds are potential candidate materials for microwave ceramics with high dielectric constant, electro-optic, pyroelectric and piezoelectric devices. The system Sr-Nb-O contains many ternary oxides out of which we have investigated the thermodynamic parameters for the compound Sr 5 Nb 4 O 15 in the present study
Ferreira, D. J. S.; Bezerra, B. N.; Collyer, M. N.; Garcia, A.; Ferreira, I. L.
2018-04-01
The simulation of casting processes demands accurate information on the thermophysical properties of the alloy; however, such information is scarce in the literature for multicomponent alloys. Generally, metallic alloys applied in industry have more than three solute components. In the present study, a general solution of Butler's formulation for surface tension is presented for multicomponent alloys and is applied in quaternary Al-Cu-Si-Fe alloys, thus permitting the Gibbs-Thomson coefficient to be determined. Such coefficient is a determining factor to the reliability of predictions furnished by microstructure growth models and by numerical computations of solidification thermal parameters, which will depend on the thermophysical properties assumed in the calculations. The Gibbs-Thomson coefficient for ternary and quaternary alloys is seldom reported in the literature. A numerical model based on Powell's hybrid algorithm and a finite difference Jacobian approximation has been coupled to a Thermo-Calc TCAPI interface to assess the excess Gibbs energy of the liquid phase, permitting liquidus temperature, latent heat, alloy density, surface tension and Gibbs-Thomson coefficient for Al-Cu-Si-Fe hypoeutectic alloys to be calculated, as an example of calculation capabilities for multicomponent alloys of the proposed method. The computed results are compared with thermophysical properties of binary Al-Cu and ternary Al-Cu-Si alloys found in the literature and presented as a function of the Cu solute composition.
Low-dose dual-energy cone-beam CT using a total-variation minimization algorithm
International Nuclear Information System (INIS)
Min, Jong Hwan
2011-02-01
Dual-energy cone-beam CT is an important imaging modality in diagnostic applications, and may also find its use in other application such as therapeutic image guidance. Despite of its clinical values, relatively high radiation dose of dual-energy scan may pose a challenge to its wide use. In this work, we investigated a low-dose, pre-reconstruction type of dual-energy cone-beam CT (CBCT) using a total-variation minimization algorithm for image reconstruction. An empirical dual-energy calibration method was used to prepare material-specific projection data. Raw data at high and low tube voltages are converted into a set of basis functions which can be linearly combined to produce material-specific data using the coefficients obtained through the calibration process. From much fewer views than are conventionally used, material specific images are reconstructed by use of the total-variation minimization algorithm. An experimental study was performed to demonstrate the feasibility of the proposed method using a micro-CT system. We have reconstructed images of the phantoms from only 90 projections acquired at tube voltages of 40 kVp and 90 kVp each. Aluminum-only and acryl-only images were successfully decomposed. We evaluated the quality of the reconstructed images by use of contrast-to-noise ratio and detectability. A low-dose dual-energy CBCT can be realized via the proposed method by greatly reducing the number of projections
DEFF Research Database (Denmark)
Yang, Yongheng; Koutroulis, Eftichios; Sangwongwanich, Ariya
2015-01-01
. An increase of the inverter lifetime and a reduction of the energy yield can alter the cost of energy, demanding an optimization of the power limitation. Therefore, aiming at minimizing the Levelized Cost of Energy (LCOE), the power limit is optimized for the AAPC strategy in this paper. The optimization...... control strategy, the Absolute Active Power Control (AAPC) can effectively solve the overloading issues by limiting the maximum possible PV power to a certain level (i.e., the power limitation), and also benefit the inverter reliability. However, its feasibility is challenged by the energy loss......, compared to the conventional PV inverter operating only in the maximum power point tracking mode. In the presented case study, the minimum of LCOE is achieved for the system when the power limit is optimized to a certain level of the designed maximum feed-in power (i.e., 3 kW). In addition, the proposed...
Energy Technology Data Exchange (ETDEWEB)
Yousefi, M.; Omid, M.; Rafiee, Sh. [Department of Agricultural Machinery Engineering, University of Tehran, Karaj (Iran, Islamic Republic of); Ghaderi, S. F. [Department of Industrial Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)
2013-07-01
Iran's primary energy consumption (PEC) was modeled as a linear function of five socioeconomic and meteorological explanatory variables using particle swarm optimization (PSO) and artificial neural networks (ANNs) techniques. Results revealed that ANN outperforms PSO model to predict test data. However, PSO technique is simple and provided us with a closed form expression to forecast PEC. Energy demand was forecasted by PSO and ANN using represented scenario. Finally, adapting about 10% renewable energy revealed that based on the developed linear programming (LP) model under minimum CO2 emissions, Iran will emit about 2520 million metric tons CO2 in 2025. The LP model indicated that maximum possible development of hydropower, geothermal and wind energy resources will satisfy the aim of minimization of CO2 emissions. Therefore, the main strategic policy in order to reduce CO2 emissions would be exploitation of these resources.
Energy Technology Data Exchange (ETDEWEB)
Yousefi, M.; Omid, M.; Rafiee, Sh. [Department of Agricultural Machinery Engineering, University of Tehran, Karaj (Iran, Islamic Republic of); Ghaderi, S.F. [Department of Industrial Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)
2013-07-01
Iran's primary energy consumption (PEC) was modeled as a linear function of five socioeconomic and meteorological explanatory variables using particle swarm optimization (PSO) and artificial neural networks (ANNs) techniques. Results revealed that ANN outperforms PSO model to predict test data. However, PSO technique is simple and provided us with a closed form expression to forecast PEC. Energy demand was forecasted by PSO and ANN using represented scenario. Finally, adapting about 10% renewable energy revealed that based on the developed linear programming (LP) model under minimum CO2 emissions, Iran will emit about 2520 million metric tons CO2 in 2025. The LP model indicated that maximum possible development of hydropower, geothermal and wind energy resources will satisfy the aim of minimization of CO2 emissions. Therefore, the main strategic policy in order to reduce CO2 emissions would be exploitation of these resources.
Overbey, Douglas M; Hilton, Sarah A; Chapman, Brandon C; Townsend, Nicole T; Barnett, Carlton C; Robinson, Thomas N; Jones, Edward L
2017-11-01
Energy-based devices are used in nearly every laparoscopic operation. Radiofrequency energy can transfer to nearby instruments via antenna and capacitive coupling without direct contact. Previous studies have described inadvertent energy transfer through bundled cords and nonelectrically active wires. The purpose of this study was to describe a new mechanism of stray energy transfer from the monopolar instrument through the operating surgeon to the laparoscopic telescope and propose practical measures to decrease the risk of injury. Radiofrequency energy was delivered to a laparoscopic L-hook (monopolar "bovie"), an advanced bipolar device, and an ultrasonic device in a laparoscopic simulator. The tip of a 10-mm telescope was placed adjacent but not touching bovine liver in a standard four-port laparoscopic cholecystectomy setup. Temperature increase was measured as tissue temperature from baseline nearest the tip of the telescope which was never in contact with the energy-based device after a 5-s open-air activation. The monopolar L-hook increased tissue temperature adjacent to the camera/telescope tip by 47 ± 8°C from baseline (P energy devices significantly reduced temperature change in comparison to the monopolar instrument (47 ± 8°C) for both the advanced bipolar (1.2 ± 0.5°C; P energy transfers from the monopolar "bovie" instrument through the operating surgeon to standard electrically inactive laparoscopic instruments. Hand-to-hand coupling describes a new form of capacitive coupling where the surgeon's body acts as an electrical conductor to transmit energy. Strategies to reduce stray energy transfer include avoiding the same surgeon holding the active electrode and laparoscopic camera or using alternative energy devices. Copyright © 2017 Elsevier Inc. All rights reserved.
International Nuclear Information System (INIS)
Boeri, Marco; Longo, Alberto
2017-01-01
This study provides a methodologically rigorous attempt to disentangle the impact of various factors – unobserved heterogeneity, information and environmental attitudes – on the inclination of individuals to exhibit either a utility maximization or a regret minimization behaviour in a discrete choice experiment for renewable energy programmes described by four attributes: greenhouse gas emissions, power outages, employment in the energy sector, and electricity bill. We explore the ability of different models – multinomial logit, random parameters logit, and hybrid latent class – and of different choice paradigms – utility maximization and regret minimization – in explaining people's choices for renewable energy programmes. The “pure” random regret random parameters logit model explains the choices of our respondents better than other models, indicating that regret is an important choice paradigm, and that choices for renewable energy programmes are mostly driven by regret, rather than by rejoice. In particular, we find that our respondents' choices are driven more by changes in greenhouse gas emissions than by reductions in power outages. Finally, we find that changing the level of information to one attribute has no effect on choices, and that being a member of an environmental organization makes a respondent more likely to be associated with the utility maximization choice framework. - Highlights: • The first paper to use the Random Regret Minimization choice paradigm in energy economics • With a hybrid latent class model, choices conform to either utility or pure random regret. • The pure random regret random parameters logit model outperforms other models. • Reducing greenhouse gas emissions is more important than reducing power outages.
Martyushev, Leonid M.
2018-03-01
The paper [1] is certainly very useful and important for understanding living systems (e.g. brain) as adaptive, self-organizing patterns. There is no need to enumerate all advantages of the paper, they are obvious. The purpose of my brief comment is to discuss one issue which, as I see it, was not thought out by the authors well enough. As a consequence, their ideas do not find as wide distribution as they otherwise could have found. This issue is related to the name selected for the principle forming the basis of their approach: free-energy principle (FEP). According to the sec. 2.1 [1]: "It asserts that all biological systems maintain their integrity by actively reducing the disorder or dispersion (i.e., entropy) of their sensory and physiological states by minimizing their variational free energy." Let us note that the authors suggested different names for the principle in their earlier works (an objective function, a function of the ensemble density encoded by the organism's configuration and the sensory data to which it is exposed, etc.), and explicitly and correctly mentioned that the free energy and entropy considered by them had nothing in common with the quantities employed in physics [2,3]. It is also obvious that a purely information-theoretic approach used by the authors with regard to the problems under study allows many other wordings and interpretations. However, in spite of this fact, in their last papers as well as in the present paper, the authors choose specifically FEP. Apparently, it may be explained by the intent to additionally base their approach on the foundation of statistical thermodynamics and therefore to demonstrate the universality of the described method. However, this is exactly what might cause misunderstandings specifically among physicists and consequently in their rejection and ignoring of FEP. The physical analogy employed by the authors has the following fundamental inconsistencies: In physics, free energy is used to describe
Minimization of energy and surface roughness of the products machined by milling
Belloufi, A.; Abdelkrim, M.; Bouakba, M.; Rezgui, I.
2017-08-01
Metal cutting represents a large portion in the manufacturing industries, which makes this process the largest consumer of energy. Energy consumption is an indirect source of carbon footprint, we know that CO2 emissions come from the production of energy. Therefore high energy consumption requires a large production, which leads to high cost and a large amount of CO2 emissions. At this day, a lot of researches done on the Metal cutting, but the environmental problems of the processes are rarely discussed. The right selection of cutting parameters is an effective method to reduce energy consumption because of the direct relationship between energy consumption and cutting parameters in machining processes. Therefore, one of the objectives of this research is to propose an optimization strategy suitable for machining processes (milling) to achieve the optimum cutting conditions based on the criterion of the energy consumed during the milling. In this paper the problem of energy consumed in milling is solved by an optimization method chosen. The optimization is done according to the different requirements in the process of roughing and finishing under various technological constraints.
IMPROVING THE TRANSMISSION PERFORMANCE BASED ON MINIMIZING ENERGY IN MOBILE ADHOC NETWORKS
Directory of Open Access Journals (Sweden)
Gundala Swathi
2015-06-01
Full Text Available Networking is collectively no of mobile nodes allocate users to correctly detect a distant environment. These wireless mobile networks want strong but simple, scalable, energy efficient and also self organize routing algorithms. In Mobile technology small quantity of power electronics and less power radio frequency have permit the expansion of small, comparatively economical and less power nodes, are associated in a wireless mobile networkIn this study we proposed method are: energy effectiveness, energetic occurrence zone and multiple hop TRANSMIT, taking into concern between the energy of transmit nodes and distance from the transmit node to the trusted neighbor node, link weight energy utilization and distance are measured as most important constraint for decide on greatest possible path from Zone Head (ZH to the neighbor node. In this we use the different constraints and lessen the quantity of distribution messages during the Transmit node choice point to decrease the energy utilization of the complete network.
Latella, Ivan; Pérez-Madrid, Agustín
2013-10-01
The local thermodynamics of a system with long-range interactions in d dimensions is studied using the mean-field approximation. Long-range interactions are introduced through pair interaction potentials that decay as a power law in the interparticle distance. We compute the local entropy, Helmholtz free energy, and grand potential per particle in the microcanonical, canonical, and grand canonical ensembles, respectively. From the local entropy per particle we obtain the local equation of state of the system by using the condition of local thermodynamic equilibrium. This local equation of state has the form of the ideal gas equation of state, but with the density depending on the potential characterizing long-range interactions. By volume integration of the relation between the different thermodynamic potentials at the local level, we find the corresponding equation satisfied by the potentials at the global level. It is shown that the potential energy enters as a thermodynamic variable that modifies the global thermodynamic potentials. As a result, we find a generalized Gibbs-Duhem equation that relates the potential energy to the temperature, pressure, and chemical potential. For the marginal case where the power of the decaying interaction potential is equal to the dimension of the space, the usual Gibbs-Duhem equation is recovered. As examples of the application of this equation, we consider spatially uniform interaction potentials and the self-gravitating gas. We also point out a close relationship with the thermodynamics of small systems.
International Nuclear Information System (INIS)
Kusiak, Andrew; Xu, Guanglin; Zhang, Zijun
2014-01-01
Highlights: • We study the energy saving of HVAC systems with a data-driven approach. • We conduct an in-depth analysis of the topology of developed Neural Network based HVAC model. • We apply interior-point method to solving a Neural Network based HVAC optimization model. • The uncertain building occupancy is incorporated in the minimization of HVAC energy consumption. • A significant potential of saving HVAC energy is discovered. - Abstract: In this paper, a data-driven approach is applied to minimize energy consumption of a heating, ventilating, and air conditioning (HVAC) system while maintaining the thermal comfort of a building with uncertain occupancy level. The uncertainty of arrival and departure rate of occupants is modeled by the Poisson and uniform distributions, respectively. The internal heating gain is calculated from the stochastic process of the building occupancy. Based on the observed and simulated data, a multilayer perceptron algorithm is employed to model and simulate the HVAC system. The data-driven models accurately predict future performance of the HVAC system based on the control settings and the observed historical information. An optimization model is formulated and solved with the interior-point method. The optimization results are compared with the results produced by the simulation models
Inferring the Gibbs state of a small quantum system
International Nuclear Information System (INIS)
Rau, Jochen
2011-01-01
Gibbs states are familiar from statistical mechanics, yet their use is not limited to that domain. For instance, they also feature in the maximum entropy reconstruction of quantum states from incomplete measurement data. Outside the macroscopic realm, however, estimating a Gibbs state is a nontrivial inference task, due to two complicating factors: the proper set of relevant observables might not be evident a priori; and whenever data are gathered from a small sample only, the best estimate for the Lagrange parameters is invariably affected by the experimenter's prior bias. I show how the two issues can be tackled with the help of Bayesian model selection and Bayesian interpolation, respectively, and illustrate the use of these Bayesian techniques with a number of simple examples.
COMPUTATIONAL MODELS USED FOR MINIMIZING THE NEGATIVE IMPACT OF ENERGY ON THE ENVIRONMENT
Directory of Open Access Journals (Sweden)
Oprea D.
2012-04-01
Full Text Available Optimizing energy system is a problem that is extensively studied for many years by scientists. This problem can be studied from different views and using different computer programs. The work is characterized by one of the following calculation methods used in Europe for modelling, power system optimization. This method shall be based on reduce action of energy system on environment. Computer program used and characterized in this article is GEMIS.
On the Tsallis Entropy for Gibbs Random Fields
Czech Academy of Sciences Publication Activity Database
Janžura, Martin
2014-01-01
Roč. 21, č. 33 (2014), s. 59-69 ISSN 1212-074X R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional research plan: CEZ:AV0Z1075907 Keywords : Tsallis entropy * Gibbs random fields * phase transitions * Tsallis entropy rate Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2014/SI/janzura-0441885.pdf
Extensitivity of entropy and modern form of Gibbs paradox
International Nuclear Information System (INIS)
Home, D.; Sengupta, S.
1981-01-01
The extensivity property of entropy is clarified in the light of a critical examination of the entropy formula based on quantum statistics and the relevant thermodynamic requirement. The modern form of the Gibbs paradox, related to the discontinuous jump in entropy due to identity or non-identity of particles, is critically investigated. Qualitative framework of a new resolution of this paradox, which analyses the general effect of distinction mark on the Hamiltonian of a system of identical particles, is outlined. (author)
GibbsCluster: unsupervised clustering and alignment of peptide sequences
DEFF Research Database (Denmark)
Andreatta, Massimo; Alvarez, Bruno; Nielsen, Morten
2017-01-01
motif characterizing each cluster. Several parameters are available to customize cluster analysis, including adjustable penalties for small clusters and overlapping groups and a trash cluster to remove outliers. As an example application, we used the server to deconvolute multiple specificities in large......-scale peptidome data generated by mass spectrometry. The server is available at http://www.cbs.dtu.dk/services/GibbsCluster-2.0....
Bhattacharya, Somnath; Mukherjee, Pradip; Roy, Amit Singha; Saha, Anirban
2018-03-01
We consider a scalar field which is generally non-minimally coupled to gravity and has a characteristic cubic Galilean-like term and a generic self-interaction, as a candidate of a Dark Energy model. The system is dynamically analyzed and novel fixed points with perturbative stability are demonstrated. Evolution of the system is numerically studied near a novel fixed point which owes its existence to the Galileon character of the model. It turns out that demanding the stability of this novel fixed point puts a strong restriction on the allowed non-minimal coupling and the choice of the self-interaction. The evolution of the equation of state parameter is studied, which shows that our model predicts an accelerated universe throughout and the phantom limit is only approached closely but never crossed. Our result thus extends the findings of Coley, Dynamical systems and cosmology. Kluwer Academic Publishers, Boston (2013) for more general NMC than linear and quadratic couplings.
Stars of bosons with non-minimal energy-momentum tensor
International Nuclear Information System (INIS)
van der Bij, J.J.; Gleiser, M.
1987-02-01
We obtain spherically symmetric solutions for scalar fields with a non-minimal coupling ξ absolute value of phi 2 R to gravity. We find, for fields of mass m, maximum masses and number of particles of order M/sub max/ ∼ 0.73ξ/sup 1/2/ M/sub Planck/ 2 /m, and N/sub max/ ∼ 0.88ξ/sup 1/2/ M/sub Planck/ 2 /m 2 respectively, for large positive ξ. For large negative ξ we find, M/sub max/ ∼ 0.66 absolute value of ξ/sup 1/2/ M/sub Planck/ 2 /m, and N/sub max/ ∼ 0.72 absolute value of ξ/sup 1/2/ M/sub Planck/ 2 /m 2
Stars of bosons with non-minimal energy-momentum tensor
International Nuclear Information System (INIS)
Van der Bij, J.J.; Gleiser, M.
1987-01-01
We obtain spherically symmetric solutions for scalar fields with a non-minimal coupling ξvertical strokeφvertical stroke 2 R to gravity. We find, for zeronode fields of mass m, maximum masses and number of particles of order M max ≅ 0.73ξ 1/2 M Planck 2 /m, and N max ≅ 0.88ξ 1/2 x M Planck 2 /m 2 respectively, for large positive ξ. For large negative ξ we find M max ≅ 0.66vertical strokeξvertical stroke 1/2 M Planck 2 /m, and N max ≅ 0.72vertical strokeξvertical stroke 1/2 x M Planck 2 /m 2 . We also calculate the critical mass and particle number for higher radial nodes of the scalar field and find that both quantities grow approximately linearly for large node number n. (orig.)
La Iglesia, A.
1989-01-01
The effect of grinding on crystallinity, particle size and solubility of two samples of kaolinite was studied. The standard Gibbs free energies of formation of different ground samples were calculated from solubility measurements, and show a direct relationship between Gibbs free energy and particle size-crystallinity variation. Values of -3752.2 and -3776.4 KJ/mol. were determinated for ÎGÂºl (am) and ÎGÂºl (crys) of kaolinite, respectively. A new th...
Biomechanical energy harvesting: generating electricity during walking with minimal user effort.
Donelan, J M; Li, Q; Naing, V; Hoffer, J A; Weber, D J; Kuo, A D
2008-02-08
We have developed a biomechanical energy harvester that generates electricity during human walking with little extra effort. Unlike conventional human-powered generators that use positive muscle work, our technology assists muscles in performing negative work, analogous to regenerative braking in hybrid cars, where energy normally dissipated during braking drives a generator instead. The energy harvester mounts at the knee and selectively engages power generation at the end of the swing phase, thus assisting deceleration of the joint. Test subjects walking with one device on each leg produced an average of 5 watts of electricity, which is about 10 times that of shoe-mounted devices. The cost of harvesting-the additional metabolic power required to produce 1 watt of electricity-is less than one-eighth of that for conventional human power generation. Producing substantial electricity with little extra effort makes this method well-suited for charging powered prosthetic limbs and other portable medical devices.
Energy and environment in the 21st century : minimizing climate change.
CERN. Geneva
2003-01-01
Energy demand and economic output are coupled. Both are expected to vastly increase in this century, driven primarily by the economic and population growth of the developing world. If the present reliance on carbon-based fuels as primary energy sources continues, average global temperatures are projected to rise between 3Â° C and 6Â° C. Limiting climate change will require reduction in greenhouse gas emissions far beyond the Kyoto commitments. Time scales and options, including nuclear, will be reviewed.
Guide to Setting Thermal Comfort Criteria and Minimizing Energy Use in Delivering Thermal Comfort
Energy Technology Data Exchange (ETDEWEB)
Regnier, Cindy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2012-08-01
Historically thermal comfort in buildings has been controlled by simple dry bulb temperature settings. As we move into more sophisticated low energy building systems that make use of alternate systems such as natural ventilation, mixed mode system and radiant thermal conditioning strategies, a more complete understanding of human comfort is needed for both design and control. This guide will support building designers, owners, operators and other stakeholders in defining quantifiable thermal comfort parameters?these can be used to support design, energy analysis and the evaluation of the thermal comfort benefits of design strategies. This guide also contains information that building owners and operators will find helpful for understanding the core concepts of thermal comfort. Whether for one building, or for a portfolio of buildings, this guide will also assist owners and designers in how to identify the mechanisms of thermal comfort and space conditioning strategies most important for their building and climate, and provide guidance towards low energy design options and operations that can successfully address thermal comfort. An example of low energy design options for thermal comfort is presented in some detail for cooling, while the fundamentals to follow a similar approach for heating are presented.
Energy Minimization of Discrete Protein Titration State Models Using Graph Theory
Purvine, Emilie; Monson, Kyle; Jurrus, Elizabeth; Star, Keith; Baker, Nathan A.
2016-01-01
There are several applications in computational biophysics which require the optimization of discrete interacting states; e.g., amino acid titration states, ligand oxidation states, or discrete rotamer angles. Such optimization can be very time-consuming as it scales exponentially in the number of sites to be optimized. In this paper, we describe a new polynomial-time algorithm for optimization of discrete states in macromolecular systems. This algorithm was adapted from image processing and uses techniques from discrete mathematics and graph theory to restate the optimization problem in terms of “maximum flow-minimum cut” graph analysis. The interaction energy graph, a graph in which vertices (amino acids) and edges (interactions) are weighted with their respective energies, is transformed into a flow network in which the value of the minimum cut in the network equals the minimum free energy of the protein, and the cut itself encodes the state that achieves the minimum free energy. Because of its deterministic nature and polynomial-time performance, this algorithm has the potential to allow for the ionization state of larger proteins to be discovered. PMID:27089174
Energy Minimization of Discrete Protein Titration State Models Using Graph Theory.
Purvine, Emilie; Monson, Kyle; Jurrus, Elizabeth; Star, Keith; Baker, Nathan A
2016-08-25
There are several applications in computational biophysics that require the optimization of discrete interacting states, for example, amino acid titration states, ligand oxidation states, or discrete rotamer angles. Such optimization can be very time-consuming as it scales exponentially in the number of sites to be optimized. In this paper, we describe a new polynomial time algorithm for optimization of discrete states in macromolecular systems. This algorithm was adapted from image processing and uses techniques from discrete mathematics and graph theory to restate the optimization problem in terms of "maximum flow-minimum cut" graph analysis. The interaction energy graph, a graph in which vertices (amino acids) and edges (interactions) are weighted with their respective energies, is transformed into a flow network in which the value of the minimum cut in the network equals the minimum free energy of the protein and the cut itself encodes the state that achieves the minimum free energy. Because of its deterministic nature and polynomial time performance, this algorithm has the potential to allow for the ionization state of larger proteins to be discovered.
Shah, Rahul H.
Production costs account for the largest share of the overall cost of manufacturing facilities. With the U.S. industrial sector becoming more and more competitive, manufacturers are looking for more cost and resource efficient working practices. Operations management and production planning have shown their capability to dramatically reduce manufacturing costs and increase system robustness. When implementing operations related decision making and planning, two fields that have shown to be most effective are maintenance and energy. Unfortunately, the current research that integrates both is limited. Additionally, these studies fail to consider parameter domains and optimization on joint energy and maintenance driven production planning. Accordingly, production planning methodology that considers maintenance and energy is investigated. Two models are presented to achieve well-rounded operating strategy. The first is a joint energy and maintenance production scheduling model. The second is a cost per part model considering maintenance, energy, and production. The proposed methodology will involve a Time-of-Use electricity demand response program, buffer and holding capacity, station reliability, production rate, station rated power, and more. In practice, the scheduling problem can be used to determine a joint energy, maintenance, and production schedule. Meanwhile, the cost per part model can be used to: (1) test the sensitivity of the obtained optimal production schedule and its corresponding savings by varying key production system parameters; and (2) to determine optimal system parameter combinations when using the joint energy, maintenance, and production planning model. Additionally, a factor analysis on the system parameters is conducted and the corresponding performance of the production schedule under variable parameter conditions, is evaluated. Also, parameter optimization guidelines that incorporate maintenance and energy parameter decision making in the
Directory of Open Access Journals (Sweden)
Jie Zhang
2015-08-01
Full Text Available An intra-urban hierarchy of activity centers interconnected by non-motorized and public transportation is broadly believed to be the ideal urban spatial structure for sustainable cities. However, the proper hinterland area for centers at each level lacks empirical study. Based on the concentric structure of everyday travel distances, working centers, shopping centers, and neighborhood centers are extracted from corresponding types of POIs in 286 Chinese cities at the prefectural level and above. A U-shaped curve between Household Transportation Energy Consumption (HTEC per capita and center density at each of the three levels has been found through regression analysis. An optimal intra-urban hierarchy of activity centers is suggested to construct energy-efficient cities.
Minimizing Wind Power Producer's Balancing Costs Using Electrochemical Energy Storage: Preprint
Energy Technology Data Exchange (ETDEWEB)
Miettinen, J.; Tikka, V.; Lassila, J.; Partanen, J.; Hodge, B. M.
2014-08-01
This paper examines how electrochemical energy storage can be used to decrease the balancing costs of a wind power producer in the Nordic market. Because electrochemical energy storage is developing in both technological and financial terms, a sensitivity analysis was carried out for the most important variables in the wind-storage hybrid system. The system was studied from a wind power producer's point of view. The main result is that there are no technical limitations to using storage for reducing the balancing costs. However, in terms of economic feasibility, installing hybrid wind-storage systems such as the one studied in this paper faces challenges in both the short and long terms.
A Method for Online Steady State Energy Minimization with Application to Refrigeration Systems
DEFF Research Database (Denmark)
Larsen, Lars Finn Slot; Thybo, Claus; Stoustrup, Jakob
2004-01-01
Energy efficiency of refrigeration systems has gradually been improved with the help of control schemes utilizing the more flexible components; the efficiency is though yet far from optimal. The flexibility initiates a higher degree of freedom in choosing the operating set points while obtaining...... applies to a broader range of process systems where the lower level set-points (in the control hierarchy) can be chosen within a degree of freedom allowing an optimization of a steady state performance index....
Economic and energy assessment of minimalized soil tillage methods in maize cultivation
Piotr Szulc; Andrzej Dubas
2014-01-01
Grain yield of maize cultivated in the years 1997-2009 in monoculture and with annual tillage simplifications was assessed in energy and economy terms. Effects of no-tillage system and direct sowing (D) with cultivation with autumn deep (A) and shallow (B) ploughing and cultivation with spring pre-sowing ploughing (C) were compared. It was demonstrated that the 13-year maize grain yield in no-tillage system and direct sowing was lower by 10.4% than the yield obtained in conventional tillage s...
Minimizing the energy spread within a single bunch by shaping its charge distribution
International Nuclear Information System (INIS)
Loew, G.A.; Wang, J.W.
1985-03-01
It has been known for some time that partial compensation of the longitudinal wake field effects can be obtained for any bunch by placing it ahead of the accelerating crest (in space), thereby letting the positive rising sinusoidal field offset the negative beam loading field. The work presented in this paper shows that it is possible to obtain complete compensation, i.e., to reduce the energy spread essentially to zero by properly shaping the longitudinal charge distribution of the bunch and by placing it at the correct position on the wave. 3 refs., 5 figs., 3 tabs
Integrating Solar Heating into an Air Handling Unit to Minimize Energy Consumption
Wilson, Scott A
2010-01-01
The purpose of this project was to test a method of integrating solar heating with a small commercial air handling unit (AHU). In order to accomplish this a heat exchanger was placed in the reheat position of the AHU and piped to the solar heating system. This heat exchanger is used to supplement or replace the existing electric reheat. This method was chosen for its ability to utilize solar energy on a more year round basis when compared to a traditional heating system. It allows solar h...
Directory of Open Access Journals (Sweden)
Aiyun Gao
2017-01-01
Full Text Available A real-time optimal control of parallel hybrid electric vehicles (PHEVs with the equivalent consumption minimization strategy (ECMS is presented in this paper, whose purpose is to achieve the total equivalent fuel consumption minimization and to maintain the battery state of charge (SOC within its operation range at all times simultaneously. Vehicle and assembly models of PHEVs are established, which provide the foundation for the following calculations. The ECMS is described in detail, in which an instantaneous cost function including the fuel energy and the electrical energy is proposed, whose emphasis is the computation of the equivalent factor. The real-time optimal control strategy is designed through regarding the minimum of the total equivalent fuel consumption as the control objective and the torque split factor as the control variable. The validation of the control strategy proposed is demonstrated both in the MATLAB/Simulink/Advisor environment and under actual transportation conditions by comparing the fuel economy, the charge sustainability, and parts performance with other three control strategies under different driving cycles including standard, actual, and real-time road conditions. Through numerical simulations and real vehicle tests, the accuracy of the approach used for the evaluation of the equivalent factor is confirmed, and the potential of the proposed control strategy in terms of fuel economy and keeping the deviations of SOC at a low level is illustrated.
Li, Mengmeng; Bijker, Wietske; Stein, Alfred
2015-04-01
Two main challenges are faced when classifying urban land cover from very high resolution satellite images: obtaining an optimal image segmentation and distinguishing buildings from other man-made objects. For optimal segmentation, this work proposes a hierarchical representation of an image by means of a Binary Partition Tree (BPT) and an unsupervised evaluation of image segmentations by energy minimization. For building extraction, we apply fuzzy sets to create a fuzzy landscape of shadows which in turn involves a two-step procedure. The first step is a preliminarily image classification at a fine segmentation level to generate vegetation and shadow information. The second step models the directional relationship between building and shadow objects to extract building information at the optimal segmentation level. We conducted the experiments on two datasets of Pléiades images from Wuhan City, China. To demonstrate its performance, the proposed classification is compared at the optimal segmentation level with Maximum Likelihood Classification and Support Vector Machine classification. The results show that the proposed classification produced the highest overall accuracies and kappa coefficients, and the smallest over-classification and under-classification geometric errors. We conclude first that integrating BPT with energy minimization offers an effective means for image segmentation. Second, we conclude that the directional relationship between building and shadow objects represented by a fuzzy landscape is important for building extraction.
Energy Technology Data Exchange (ETDEWEB)
Susan J. Foulk
2012-07-24
Project Objective: The objectives of this study are to develop an accurate and stable on-line sensor system to monitor color and composition on-line in polymer melts, to develop a scheme for using the output to control extruders to eliminate the energy, material and operational costs of off-specification product, and to combine or eliminate some extrusion processes. Background: Polymer extrusion processes are difficult to control because the quality achieved in the final product is complexly affected by the properties of the extruder screw, speed of extrusion, temperature, polymer composition, strength and dispersion properties of additives, and feeder system properties. Extruder systems are engineered to be highly reproducible so that when the correct settings to produce a particular product are found, that product can be reliably produced time after time. However market conditions often require changes in the final product, different products or grades may be processed in the same equipment, and feed materials vary from lot to lot. All of these changes require empirical adjustment of extruder settings to produce a product meeting specifications. Optical sensor systems that can continuously monitor the composition and color of the extruded polymer could detect process upsets, drift, blending oscillations, and changes in dispersion of additives. Development of an effective control algorithm using the output of the monitor would enable rapid corrections for changes in materials and operating conditions, thereby eliminating most of the scrap and recycle of current processing. This information could be used to identify extruder systems issues, diagnose problem sources, and suggest corrective actions in real-time to help keep extruder system settings within the optimum control region. Using these advanced optical sensor systems would give extruder operators real-time feedback from their process. They could reduce the amount of off-spec product produced and
GPU-accelerated Gibbs ensemble Monte Carlo simulations of Lennard-Jonesium
Mick, Jason; Hailat, Eyad; Russo, Vincent; Rushaidat, Kamel; Schwiebert, Loren; Potoff, Jeffrey
2013-12-01
This work describes an implementation of canonical and Gibbs ensemble Monte Carlo simulations on graphics processing units (GPUs). The pair-wise energy calculations, which consume the majority of the computational effort, are parallelized using the energetic decomposition algorithm. While energetic decomposition is relatively inefficient for traditional CPU-bound codes, the algorithm is ideally suited to the architecture of the GPU. The performance of the CPU and GPU codes are assessed for a variety of CPU and GPU combinations for systems containing between 512 and 131,072 particles. For a system of 131,072 particles, the GPU-enabled canonical and Gibbs ensemble codes were 10.3 and 29.1 times faster (GTX 480 GPU vs. i5-2500K CPU), respectively, than an optimized serial CPU-bound code. Due to overhead from memory transfers from system RAM to the GPU, the CPU code was slightly faster than the GPU code for simulations containing less than 600 particles. The critical temperature Tc∗=1.312(2) and density ρc∗=0.316(3) were determined for the tail corrected Lennard-Jones potential from simulations of 10,000 particle systems, and found to be in exact agreement with prior mixed field finite-size scaling calculations [J.J. Potoff, A.Z. Panagiotopoulos, J. Chem. Phys. 109 (1998) 10914].
International Nuclear Information System (INIS)
Jacome, Paulo A.D.; Landim, Mariana C.; Garcia, Amauri; Furtado, Alexandre F.; Ferreira, Ivaldo L.
2011-01-01
Highlights: → Surface tension and the Gibbs-Thomson coefficient are computed for Al-based alloys. → Butler's scheme and ThermoCalc are used to compute the thermophysical properties. → Predictive cell/dendrite growth models depend on accurate thermophysical properties. → Mechanical properties can be related to the microstructural cell/dendrite spacing. - Abstract: In this paper, a solution for Butler's formulation is presented permitting the surface tension and the Gibbs-Thomson coefficient of Al-based binary alloys to be determined. The importance of Gibbs-Thomson coefficient for binary alloys is related to the reliability of predictions furnished by predictive cellular and dendritic growth models and of numerical computations of solidification thermal variables, which will be strongly dependent on the thermophysical properties assumed for the calculations. A numerical model based on Powell hybrid algorithm and a finite difference Jacobian approximation was coupled to a specific interface of a computational thermodynamics software in order to assess the excess Gibbs energy of the liquid phase, permitting the surface tension and Gibbs-Thomson coefficient for Al-Fe, Al-Ni, Al-Cu and Al-Si hypoeutectic alloys to be calculated. The computed results are presented as a function of the alloy composition.
Energy Technology Data Exchange (ETDEWEB)
Jacome, Paulo A.D.; Landim, Mariana C. [Department of Mechanical Engineering, Fluminense Federal University, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil); Garcia, Amauri, E-mail: amaurig@fem.unicamp.br [Department of Materials Engineering, University of Campinas, UNICAMP, PO Box 6122, 13083-970 Campinas, SP (Brazil); Furtado, Alexandre F.; Ferreira, Ivaldo L. [Department of Mechanical Engineering, Fluminense Federal University, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil)
2011-08-20
Highlights: {yields} Surface tension and the Gibbs-Thomson coefficient are computed for Al-based alloys. {yields} Butler's scheme and ThermoCalc are used to compute the thermophysical properties. {yields} Predictive cell/dendrite growth models depend on accurate thermophysical properties. {yields} Mechanical properties can be related to the microstructural cell/dendrite spacing. - Abstract: In this paper, a solution for Butler's formulation is presented permitting the surface tension and the Gibbs-Thomson coefficient of Al-based binary alloys to be determined. The importance of Gibbs-Thomson coefficient for binary alloys is related to the reliability of predictions furnished by predictive cellular and dendritic growth models and of numerical computations of solidification thermal variables, which will be strongly dependent on the thermophysical properties assumed for the calculations. A numerical model based on Powell hybrid algorithm and a finite difference Jacobian approximation was coupled to a specific interface of a computational thermodynamics software in order to assess the excess Gibbs energy of the liquid phase, permitting the surface tension and Gibbs-Thomson coefficient for Al-Fe, Al-Ni, Al-Cu and Al-Si hypoeutectic alloys to be calculated. The computed results are presented as a function of the alloy composition.
International Nuclear Information System (INIS)
Ogunjuyigbe, A.S.O.; Ayodele, T.R.; Akinola, O.A.
2016-01-01
Highlights: • Genetic Algorithm is used for tri-objective design of hybrid energy system. • The objective is minimizing the Life Cycle Cost, CO_2 emissions and dump energy. • Small split diesel generators are used in place of big single diesel generator. • The split diesel generators are aggregable based on certain set of rules. • The proposed algorithm achieves the set objectives (LCC, CO_2 emission and dump). - Abstract: In this paper, a Genetic Algorithm (GA) is utilized to implement a tri-objective design of a grid independent PV/Wind/Split-diesel/Battery hybrid energy system for a typical residential building with the objective of minimizing the Life Cycle Cost (LCC), CO_2 emissions and dump energy. To achieve some of these objectives, small split Diesel generators are used in place of single big Diesel generator and are aggregable based on certain set of rules depending on available renewable energy resources and state of charge of the battery. The algorithm was utilized to study five scenarios (PV/Battery, Wind/Battery, Single big Diesel generator, aggregable 3-split Diesel generators, PV/Wind/Split-diesel/Battery) for a typical load profile of a residential house using typical wind and solar radiation data. The results obtained revealed that the PV/Wind/Split-diesel/Battery is the most attractive scenario (optimal) having LCC of $11,273, COE of 0.13 ($/kW h), net dump energy of 3 MW h, and net CO_2 emission of 13,273 kg. It offers 46%, 28%, 82% and 94% reduction in LCC, COE, CO_2 emission and dump energy respectively when compared to a single big Diesel generator scenario.
Quantitative Boltzmann-Gibbs Principles via Orthogonal Polynomial Duality
Ayala, Mario; Carinci, Gioia; Redig, Frank
2018-06-01
We study fluctuation fields of orthogonal polynomials in the context of particle systems with duality. We thereby obtain a systematic orthogonal decomposition of the fluctuation fields of local functions, where the order of every term can be quantified. This implies a quantitative generalization of the Boltzmann-Gibbs principle. In the context of independent random walkers, we complete this program, including also fluctuation fields in non-stationary context (local equilibrium). For other interacting particle systems with duality such as the symmetric exclusion process, similar results can be obtained, under precise conditions on the n particle dynamics.
Near-Optimal Detection in MIMO Systems using Gibbs Sampling
DEFF Research Database (Denmark)
Hansen, Morten; Hassibi, Babak; Dimakis, Georgios Alexandros
2009-01-01
In this paper we study a Markov Chain Monte Carlo (MCMC) Gibbs sampler for solving the integer least-squares problem. In digital communication the problem is equivalent to preforming Maximum Likelihood (ML) detection in Multiple-Input Multiple-Output (MIMO) systems. While the use of MCMC methods...... sampler provides a computationally efficient way of achieving approximative ML detection in MIMO systems having a huge number of transmit and receive dimensions. In fact, they further suggest that the Markov chain is rapidly mixing. Thus, it has been observed that even in cases were ML detection using, e...
Detuning Minimization of Induction Motor Drive System for Alternative Energy Vehicles
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Habibur Rehman
2015-08-01
Full Text Available This paper evaluates different types of AC machines and various control techniques for their suitability for the drive system of Alternative Energy Vehicles (AEV. An Indirect Field Oriented (IFO drive system for the AEV application is chosen and its major problem of detuning is addressed by designing an offline and an online rotor resistance adaptation technique. The offline scheme sets the slip gain at various operating conditions based on the fact that if the rotor resistance is set correctly and field orientation is achieved, then there should be a linear relationship between the torque current and the output torque. The online technique is designed using Model Reference Adaptive System (MRAS for the rotor resistance adaptation. For an ideal field oriented machine, the rotor flux along the q-axis should be zero. This condition acts as a reference model for the proposed MRAS scheme. The current model flux observer in the synchronous frame of reference is selected as an adjustable model and its rotor resistance is tuned so that the flux along the q-axis becomes zero. The effectiveness of the offline tuning scheme is evident through performance validation of the drive system, which is implemented in a real Ford vehicle. The experimental results obtained while driving the test vehicle are included in the paper while the proposed online scheme is validated on a 3.75 kW prototype induction motor.
Thermodynamic free-energy minimization for unsupervised fusion of dual-color infrared breast images
Szu, Harold; Miao, Lidan; Qi, Hairong
2006-04-01
function [A] may vary from the point tumor to its neighborhood, we could not rely on neighborhood statistics as did in a popular unsupervised independent component analysis (ICA) mathematical statistical method, we instead impose the physics equilibrium condition of the minimum of Helmholtz free-energy, H = E - T °S. In case of the point breast cancer, we can assume the constant ground state energy E ° to be normalized by those benign neighborhood tissue, and then the excited state can be computed by means of Taylor series expansion in terms of the pixel I/O data. We can augment the X-ray mammogram technique with passive IR imaging to reduce the unwanted X-rays during the chemotherapy recovery. When the sequence is animated into a movie, and the recovery dynamics is played backward in time, the movie simulates the cameras' potential for early detection without suffering the PD=0.1 search uncertainty. In summary, we applied two satellite-grade dual-color IR imaging cameras and advanced military (automatic target recognition) ATR spectrum fusion algorithm at the middle wavelength IR (3 - 5μm) and long wavelength IR (8 - 12μm), which are capable to screen malignant tumors proved by the time-reverse fashion of the animated movie experiments. On the contrary, the traditional thermal breast scanning/imaging, known as thermograms over decades, was IR spectrum-blind, and limited to a single night-vision camera and the necessary waiting for the cool down period for taking a second look for change detection suffers too many environmental and personnel variabilities.
Just Another Gibbs Additive Modeler: Interfacing JAGS and mgcv
Directory of Open Access Journals (Sweden)
Simon N. Wood
2016-12-01
Full Text Available The BUGS language offers a very flexible way of specifying complex statistical models for the purposes of Gibbs sampling, while its JAGS variant offers very convenient R integration via the rjags package. However, including smoothers in JAGS models can involve some quite tedious coding, especially for multivariate or adaptive smoothers. Further, if an additive smooth structure is required then some care is needed, in order to centre smooths appropriately, and to find appropriate starting values. R package mgcv implements a wide range of smoothers, all in a manner appropriate for inclusion in JAGS code, and automates centring and other smooth setup tasks. The purpose of this note is to describe an interface between mgcv and JAGS, based around an R function, jagam, which takes a generalized additive model (GAM as specified in mgcv and automatically generates the JAGS model code and data required for inference about the model via Gibbs sampling. Although the auto-generated JAGS code can be run as is, the expectation is that the user would wish to modify it in order to add complex stochastic model components readily specified in JAGS. A simple interface is also provided for visualisation and further inference about the estimated smooth components using standard mgcv functionality. The methods described here will be un-necessarily inefficient if all that is required is fully Bayesian inference about a standard GAM, rather than the full flexibility of JAGS. In that case the BayesX package would be more efficient.
Reflections on Gibbs: From Statistical Physics to the Amistad V3.0
Kadanoff, Leo P.
2014-07-01
This note is based upon a talk given at an APS meeting in celebration of the achievements of J. Willard Gibbs. J. Willard Gibbs, the younger, was the first American physical sciences theorist. He was one of the inventors of statistical physics. He introduced and developed the concepts of phase space, phase transitions, and thermodynamic surfaces in a remarkably correct and elegant manner. These three concepts form the basis of different areas of physics. The connection among these areas has been a subject of deep reflection from Gibbs' time to our own. This talk therefore celebrated Gibbs by describing modern ideas about how different parts of physics fit together. I finished with a more personal note. Our own J. Willard Gibbs had all his many achievements concentrated in science. His father, also J. Willard Gibbs, also a Professor at Yale, had one great non-academic achievement that remains unmatched in our day. I describe it.
Bistafa, Carlos; Kitamura, Yukichi; Martins-Costa, Marilia T C; Nagaoka, Masataka; Ruiz-López, Manuel F
2018-05-22
We describe a method to locate stationary points in the free-energy hypersurface of complex molecular systems using high-level correlated ab initio potentials. In this work, we assume a combined QM/MM description of the system although generalization to full ab initio potentials or other theoretical schemes is straightforward. The free-energy gradient (FEG) is obtained as the mean force acting on relevant nuclei using a dual level strategy. First, a statistical simulation is carried out using an appropriate, low-level quantum mechanical force-field. Free-energy perturbation (FEP) theory is then used to obtain the free-energy derivatives for the target, high-level quantum mechanical force-field. We show that this composite FEG-FEP approach is able to reproduce the results of a standard free-energy minimization procedure with high accuracy, while simultaneously allowing for a drastic reduction of both computational and wall-clock time. The method has been applied to study the structure of the water molecule in liquid water at the QCISD/aug-cc-pVTZ level of theory, using the sampling from QM/MM molecular dynamics simulations at the B3LYP/6-311+G(d,p) level. The obtained values for the geometrical parameters and for the dipole moment of the water molecule are within the experimental error, and they also display an excellent agreement when compared to other theoretical estimations. The developed methodology represents therefore an important step toward the accurate determination of the mechanism, kinetics, and thermodynamic properties of processes in solution, in enzymes, and in other disordered chemical systems using state-of-the-art ab initio potentials.
International Nuclear Information System (INIS)
Gatti, R; UhlIk, F; Montalenti, F
2008-01-01
We present a novel computational method for finding the concentration profile which minimizes the elastic energy stored in heteroepitaxial islands. Based on a suitable combination of continuum elasticity theory and configurational Monte Carlo, we show that such profiles can be readily found by a simple, yet fully self-consistent, iterative procedure. We apply the method to SiGe/Si islands, considering realistic three-dimensional shapes (pyramids, domes and barns), finding strongly non-uniform distributions of Si and Ge atoms, in qualitative agreement with several experiments. Moreover, our simulated selective-etching profiles display, in some cases, a remarkable resemblance to the experimental ones, opening intriguing questions on the interplay between kinetic, entropic and elastic effects
Continuous spin mean-field models : Limiting kernels and Gibbs properties of local transforms
Kulske, Christof; Opoku, Alex A.
2008-01-01
We extend the notion of Gibbsianness for mean-field systems to the setup of general (possibly continuous) local state spaces. We investigate the Gibbs properties of systems arising from an initial mean-field Gibbs measure by application of given local transition kernels. This generalizes previous
Large scale inference in the Infinite Relational Model: Gibbs sampling is not enough
DEFF Research Database (Denmark)
Albers, Kristoffer Jon; Moth, Andreas Leon Aagard; Mørup, Morten
2013-01-01
. We find that Gibbs sampling can be computationally scaled to handle millions of nodes and billions of links. Investigating the behavior of the Gibbs sampler for different sizes of networks we find that the mixing ability decreases drastically with the network size, clearly indicating a need...
One of Gibbs's ideas that has gone unnoticed (comment on chapter IX of his classic book)
International Nuclear Information System (INIS)
Sukhanov, Alexander D; Rudoi, Yurii G
2006-01-01
We show that contrary to the commonly accepted view, Chapter IX of Gibbs's book [1] contains the prolegomena to a macroscopic statistical theory that is qualitatively different from his own microscopic statistical mechanics. The formulas obtained by Gibbs were the first results in the history of physics related to the theory of fluctuations in any macroparameters, including temperature. (from the history of physics)
Dynamical predictive power of the generalized Gibbs ensemble revealed in a second quench.
Zhang, J M; Cui, F C; Hu, Jiangping
2012-04-01
We show that a quenched and relaxed completely integrable system is hardly distinguishable from the corresponding generalized Gibbs ensemble in a dynamical sense. To be specific, the response of the quenched and relaxed system to a second quench can be accurately reproduced by using the generalized Gibbs ensemble as a substitute. Remarkably, as demonstrated with the transverse Ising model and the hard-core bosons in one dimension, not only the steady values but even the transient, relaxation dynamics of the physical variables can be accurately reproduced by using the generalized Gibbs ensemble as a pseudoinitial state. This result is an important complement to the previously established result that a quenched and relaxed system is hardly distinguishable from the generalized Gibbs ensemble in a static sense. The relevance of the generalized Gibbs ensemble in the nonequilibrium dynamics of completely integrable systems is then greatly strengthened.
Bahamonde, Sebastian; Marciu, Mihai; Rudra, Prabir
2018-04-01
Within this work, we propose a new generalised quintom dark energy model in the teleparallel alternative of general relativity theory, by considering a non-minimal coupling between the scalar fields of a quintom model with the scalar torsion component T and the boundary term B. In the teleparallel alternative of general relativity theory, the boundary term represents the divergence of the torsion vector, B=2∇μTμ, and is related to the Ricci scalar R and the torsion scalar T, by the fundamental relation: R=‑T+B. We have investigated the dynamical properties of the present quintom scenario in the teleparallel alternative of general relativity theory by performing a dynamical system analysis in the case of decomposable exponential potentials. The study analysed the structure of the phase space, revealing the fundamental dynamical effects of the scalar torsion and boundary couplings in the case of a more general quintom scenario. Additionally, a numerical approach to the model is presented to analyse the cosmological evolution of the system.
International Nuclear Information System (INIS)
Bascietto, J.J.; Martin, J.F.; Duke, C.S.; Gray, S.I.
1991-01-01
Fifty years of research, development and production in support of national defense have left the Department of Energy (DOE) with numerous radioactive, hazardous and mixed waste sites requiring environmental restoration and remediation. The responsibilities for DOE associated with releases of these wastes into the environment are driving major efforts to characterize contamination problems and identify and implement environmental restoration and remediation alternatives. The subject of this paper is the recently issued DOE guidance to minimize the basis for damage claims for injuries to natural resources on, over and under lands owned or controlled by DOE associated with the releases of hazardous substances from DOE facilities. Depending on the regulatory authority governing the facility, the preferred means of evaluating the possibility of injury to natural resources is the preparation of an ecological risk assessment or an environmental evaluation. As both the natural resource trustee and lead agency at facilities under its control, DOE receives dual responsibility requiring site remediation if necessary, and that any injured natural resources be restored, or that compensation for the injuries is made. Several executive and legislative sources of authority and responsibility with regard to lead agencies and trustees of natural resources will be detailed. Also, ongoing remedial investigation/feasibility study work at the DOE Fernald Environmental Management Project near Fernald, Ohio will be described as an example of how this guidance can be applied
Dierkes, Ulrich; Sauvigny, Friedrich; Jakob, Ruben; Kuster, Albrecht
2010-01-01
Minimal Surfaces is the first volume of a three volume treatise on minimal surfaces (Grundlehren Nr. 339-341). Each volume can be read and studied independently of the others. The central theme is boundary value problems for minimal surfaces. The treatise is a substantially revised and extended version of the monograph Minimal Surfaces I, II (Grundlehren Nr. 295 & 296). The first volume begins with an exposition of basic ideas of the theory of surfaces in three-dimensional Euclidean space, followed by an introduction of minimal surfaces as stationary points of area, or equivalently
Thermodynamics of the Schwarzschild-AdS Black Hole with a Minimal Length
Directory of Open Access Journals (Sweden)
Yan-Gang Miao
2017-01-01
Full Text Available Using the mass-smeared scheme of black holes, we study the thermodynamics of black holes. Two interesting models are considered. One is the self-regular Schwarzschild-AdS black hole whose mass density is given by the analogue to probability densities of quantum hydrogen atoms. The other model is the same black hole but whose mass density is chosen to be a rational fractional function of radial coordinates. Both mass densities are in fact analytic expressions of the δ-function. We analyze the phase structures of the two models by investigating the heat capacity at constant pressure and the Gibbs free energy in an isothermal-isobaric ensemble. Both models fail to decay into the pure thermal radiation even with the positive Gibbs free energy due to the existence of a minimal length. Furthermore, we extend our analysis to a general mass-smeared form that is also associated with the δ-function and indicate the similar thermodynamic properties for various possible mass-smeared forms based on the δ-function.
Modeling adsorption of cationic surfactants at air/water interface without using the Gibbs equation.
Phan, Chi M; Le, Thu N; Nguyen, Cuong V; Yusa, Shin-ichi
2013-04-16
The Gibbs adsorption equation has been indispensable in predicting the surfactant adsorption at the interfaces, with many applications in industrial and natural processes. This study uses a new theoretical framework to model surfactant adsorption at the air/water interface without the Gibbs equation. The model was applied to two surfactants, C14TAB and C16TAB, to determine the maximum surface excesses. The obtained values demonstrated a fundamental change, which was verified by simulations, in the molecular arrangement at the interface. The new insights, in combination with recent discoveries in the field, expose the limitations of applying the Gibbs adsorption equation to cationic surfactants at the air/water interface.
International Nuclear Information System (INIS)
1988-09-01
The first workshop on hazardous and mixed waste minimization was held in Las Vegas, Nevada, on July 26--28, 1988. The objective of this workshop was to establish an interchange between DOE headquarters (DOE-HQ) DP, Operations Offices, and contractors of waste minimization strategies and successes. The first day of the workshop began with presentations stressing the importance of establishing a waste minimization program at each site as required by RCRA, the land ban restrictions, and the decrease in potential liabilities associated with waste disposal. Discussions were also centered on pending legislation which would create an Office of Waste Reduction in the Environmental Protection Agency (EPA). The Waste Minimization and Avoidance Study was initiated by DOE as an addition to the long-term productivity study to address the issues of evolving requirements facing RCRA waste management activities at the DP sites, to determine how major operations will be affected by these requirements, and to determine the available strategies and options for waste minimization and avoidance. Waste minimization was defined in this study as source reduction and recycling
An Introduction to the DA-T Gibbs Sampler for the Two-Parameter Logistic (2PL Model and Beyond
Directory of Open Access Journals (Sweden)
Gunter Maris
2005-01-01
Full Text Available The DA-T Gibbs sampler is proposed by Maris and Maris (2002 as a Bayesian estimation method for a wide variety of Item Response Theory (IRT models. The present paper provides an expository account of the DAT Gibbs sampler for the 2PL model. However, the scope is not limited to the 2PL model. It is demonstrated how the DA-T Gibbs sampler for the 2PL may be used to build, quite easily, Gibbs samplers for other IRT models. Furthermore, the paper contains a novel, intuitive derivation of the Gibbs sampler and could be read for a graduate course on sampling.
Comparison of Boltzmann and Gibbs entropies for the analysis of single-chain phase transitions
Shakirov, T.; Zablotskiy, S.; Böker, A.; Ivanov, V.; Paul, W.
2017-03-01
In the last 10 years, flat histogram Monte Carlo simulations have contributed strongly to our understanding of the phase behavior of simple generic models of polymers. These simulations result in an estimate for the density of states of a model system. To connect this result with thermodynamics, one has to relate the density of states to the microcanonical entropy. In a series of publications, Dunkel, Hilbert and Hänggi argued that it would lead to a more consistent thermodynamic description of small systems, when one uses the Gibbs definition of entropy instead of the Boltzmann one. The latter is the logarithm of the density of states at a certain energy, the former is the logarithm of the integral of the density of states over all energies smaller than or equal to this energy. We will compare the predictions using these two definitions for two polymer models, a coarse-grained model of a flexible-semiflexible multiblock copolymer and a coarse-grained model of the protein poly-alanine. Additionally, it is important to note that while Monte Carlo techniques are normally concerned with the configurational energy only, the microcanonical ensemble is defined for the complete energy. We will show how taking the kinetic energy into account alters the predictions from the analysis. Finally, the microcanonical ensemble is supposed to represent a closed mechanical N-particle system. But due to Galilei invariance such a system has two additional conservation laws, in general: momentum and angular momentum. We will also show, how taking these conservation laws into account alters the results.
A Gibbs potential expansion with a quantic system made up of a large number of particles
International Nuclear Information System (INIS)
Bloch, Claude; Dominicis, Cyrano de
1959-01-01
Starting from an expansion derived in a previous work, we study the contribution to the Gibbs potential of the two-body dynamical correlations, taking into account the statistical correlations. Such a contribution is of interest for low density systems at low temperature. In the zero density limit, it reduces to the Beth Uhlenbeck expression of the second virial coefficient. For a system of fermions in the zero temperature limit, it yields the contribution of the Brueckner reaction matrix to the ground state energy, plus, under certain conditions, additional terms of the form exp. (β |Δ|), where the Δ are the binding energies of 'bound states' of the type first discussed by L. Cooper. Finally, we study the wave function of two particles immersed in a medium (defined by its temperature and chemical potential). lt satisfies an equation generalizing the Bethe Goldstone equation for an arbitrary temperature. Reprint of a paper published in 'Nuclear Physics' 10, 1959, p. 181-196 [fr
Rapidly Mixing Gibbs Sampling for a Class of Factor Graphs Using Hierarchy Width.
De Sa, Christopher; Zhang, Ce; Olukotun, Kunle; Ré, Christopher
2015-12-01
Gibbs sampling on factor graphs is a widely used inference technique, which often produces good empirical results. Theoretical guarantees for its performance are weak: even for tree structured graphs, the mixing time of Gibbs may be exponential in the number of variables. To help understand the behavior of Gibbs sampling, we introduce a new (hyper)graph property, called hierarchy width . We show that under suitable conditions on the weights, bounded hierarchy width ensures polynomial mixing time. Our study of hierarchy width is in part motivated by a class of factor graph templates, hierarchical templates , which have bounded hierarchy width-regardless of the data used to instantiate them. We demonstrate a rich application from natural language processing in which Gibbs sampling provably mixes rapidly and achieves accuracy that exceeds human volunteers.
The MaxEnt extension of a quantum Gibbs family, convex geometry and geodesics
International Nuclear Information System (INIS)
Weis, Stephan
2015-01-01
We discuss methods to analyze a quantum Gibbs family in the ultra-cold regime where the norm closure of the Gibbs family fails due to discontinuities of the maximum-entropy inference. The current discussion of maximum-entropy inference and irreducible correlation in the area of quantum phase transitions is a major motivation for this research. We extend a representation of the irreducible correlation from finite temperatures to absolute zero
Uniqueness of Gibbs Measure for Models with Uncountable Set of Spin Values on a Cayley Tree
International Nuclear Information System (INIS)
Eshkabilov, Yu. Kh.; Haydarov, F. H.; Rozikov, U. A.
2013-01-01
We consider models with nearest-neighbor interactions and with the set [0, 1] of spin values, on a Cayley tree of order K ≥ 1. It is known that the ‘splitting Gibbs measures’ of the model can be described by solutions of a nonlinear integral equation. For arbitrary k ≥ 2 we find a sufficient condition under which the integral equation has unique solution, hence under the condition the corresponding model has unique splitting Gibbs measure.
Klaassen, M.R.J.; Lindstrom, A.
1996-01-01
Lindstrom & Alerstam (1992 Am. Nat. 140, 477-491) presented a model that predicts optimal departure fuel loads as a function of the rate of fuel deposition in time-minimizing migrants. The basis of the model is that the coverable distance per unit of fuel deposited, diminishes with increasing fuel
Gelb, Lev D; Chakraborty, Somendra Nath
2011-12-14
The normal boiling points are obtained for a series of metals as described by the "quantum-corrected Sutton Chen" (qSC) potentials [S.-N. Luo, T. J. Ahrens, T. Çağın, A. Strachan, W. A. Goddard III, and D. C. Swift, Phys. Rev. B 68, 134206 (2003)]. Instead of conventional Monte Carlo simulations in an isothermal or expanded ensemble, simulations were done in the constant-NPH adabatic variant of the Gibbs ensemble technique as proposed by Kristóf and Liszi [Chem. Phys. Lett. 261, 620 (1996)]. This simulation technique is shown to be a precise tool for direct calculation of boiling temperatures in high-boiling fluids, with results that are almost completely insensitive to system size or other arbitrary parameters as long as the potential truncation is handled correctly. Results obtained were validated using conventional NVT-Gibbs ensemble Monte Carlo simulations. The qSC predictions for boiling temperatures are found to be reasonably accurate, but substantially underestimate the enthalpies of vaporization in all cases. This appears to be largely due to the systematic overestimation of dimer binding energies by this family of potentials, which leads to an unsatisfactory description of the vapor phase. © 2011 American Institute of Physics
A study of the Boltzmann and Gibbs entropies in the context of a stochastic toy model
Malgieri, Massimiliano; Onorato, Pasquale; De Ambrosis, Anna
2018-05-01
In this article we reconsider a stochastic toy model of thermal contact, first introduced in Onorato et al (2017 Eur. J. Phys. 38 045102), showing its educational potential for clarifying some current issues in the foundations of thermodynamics. The toy model can be realized in practice using dice and coins, and can be seen as representing thermal coupling of two subsystems with energy bounded from above. The system is used as a playground for studying the different behaviours of the Boltzmann and Gibbs temperatures and entropies in the approach to steady state. The process that models thermal contact between the two subsystems can be proved to be an ergodic, reversible Markov chain; thus the dynamics produces an equilibrium distribution in which the weight of each state is proportional to its multiplicity in terms of microstates. Each one of the two subsystems, taken separately, is formally equivalent to an Ising spin system in the non-interacting limit. The model is intended for educational purposes, and the level of readership of the article is aimed at advanced undergraduates.
Chowdhury, Nahid -UR-Rahman; Reza, Syed Enam; Nitol, Tofaeel Ahamed; Mahabub, Abd-Al-Fattah IBNE
2016-01-01
Abstract- Bangladesh is a densely populated country located at the South-East corner of Asia. Only 48.5% of people here have access to the grid electricity. This paper provides a comprehensive study of the contemporary renewable energy scenario in Bangladesh in terms of distribution, research and infrastructural development in the country. Renewable energy is the smartest solution of increasing energy crisis caused by using fossil fuels. But sometimes it faces question of reliability which ca...
Energy Technology Data Exchange (ETDEWEB)
Barkenbus, J.N.; Leff, H.S.
1983-01-01
Since the oil embargo of 1973, state governments have increased their efforts to track and understand energy flows within their boundaries. There is a commonly perceived need to comprehend the status of present and expected future energy availability, demand, and price and to be prepared to exercise responsible and effective management during energy emergencies. This responsibility has brought with it new needs for accurate and timely state-level information on energy transactions and the external parameters that effect energy availability and disposition. What energy data are needed by a state, regardless of its idiosyncracies, during both normal and energy emergency periods, and to what extent are these data available now. The authors find that needed ongoing (core) data are only partially available at present, and that emergency data can be obtained only with a carefully planned monitoring program that can be fitted to specific emergency conditions. Overall, this paper provides a realistic assessment of the state-level energy data needed to provide state policy makers with sufficient information to make considered judgments.
Energy Technology Data Exchange (ETDEWEB)
Barkenbus, J.N.; Leff, H.S.
1983-01-01
Since the oil embargo of 1973, state governments have increased their efforts to track and understand energy flows within their boundaries. There is a commonly perceived need to comprehend the status of present and expected future energy availability, demand, and price and to be prepared to exercise responsible and effective management during energy emergencies. This responsibility has brought with it new needs for accurate and timely state-level information on energy transactions and the external parameters that effect energy availability and disposition. Hence, we ask: what energy data are needed by a state, regardless of its idiosyncracies, during both normal and energy emergency periods, and to what extent are these data available now. We find that needed ongoing (core) data are only partially available at present, and that emergency data can be obtained only with a carefully planned monitoring program that can be fitted to specific emergency conditions. Overall, this paper provides a realistic assessment of the state-level energy data needed to provide state policy makers with sufficient information to make considered judgments. 7 references, 6 tables.
Thorlton, Janet; Colby, David A; Devine, Paige
2014-07-01
Energy drink sales are expected to reach $52 billion by 2016. These products, often sold as dietary supplements, typically contain stimulants. The Dietary Supplement Protection Act claims an exemplary public health safety record. However, in 2011 the number of emergency department visits related to consumption of energy drinks exceeded 20,000. Nearly half of these visits involved adverse effects occurring from product misuse. Political, social, economic, practical, and legal factors shape the landscape surrounding this issue. In this policy analysis, we examine 3 options: capping energy drink caffeine levels, creating a public education campaign, and increasing regulatory scrutiny regarding the manufacture and labeling of energy drinks. Increased regulatory scrutiny may be in order, especially in light of wrongful death lawsuits related to caffeine toxicity resulting from energy drink consumption.
DEFF Research Database (Denmark)
Schneller, Mikkel Bo; Pedersen, Mogens Theisen; Gupta, Nidhi
2015-01-01
We compared the accuracy of five objective methods, including two newly developed methods combining accelerometry and activity type recognition (Acti4), against indirect calorimetry, to estimate total energy expenditure (EE) of different activities in semi-standardized settings. Fourteen particip...
Quang-Hung, Nguyen; Thoai, Nam
2016-01-01
Infrastructure-as-a-Service (IaaS) clouds have become more popular enabling users to run applications under virtual machines. Energy efficiency for IaaS clouds is still challenge. This paper investigates the energy-efficient scheduling problems of virtual machines (VMs) onto physical machines (PMs) in IaaS clouds along characteristics: multiple resources, fixed intervals and non-preemption of virtual machines. The scheduling problems are NP-hard. Most of existing works on VM placement reduce ...
International Nuclear Information System (INIS)
Mazziotti, David A.
2002-01-01
Atomic and molecular ground-state energies are variationally determined by constraining the two-particle reduced density matrix (2-RDM) to satisfy positivity conditions. Because each positivity condition corresponds to correcting the ground-state energies for a class of Hamiltonians with two-particle interactions, these conditions collectively provide a new approach to many-body theory that, unlike perturbation theory, can capture significantly correlated phenomena including the multireference effects of potential-energy surfaces. The D, Q, and G conditions for the 2-RDM are extended through generalized lifting operators inspired from the formal solution of N-representability. These lifted conditions agree with the hierarchy of positivity conditions presented by Mazziotti and Erdahl [Phys. Rev. A 63, 042113 (2001)]. The connection between positivity and the formal solution explains how constraining higher RDMs to be positive semidefinite improves the N representability of the 2-RDM and suggests using pieces of higher positivity conditions that computationally scale like the D condition. With the D, Q, and G conditions as well as pieces of higher positivity the electronic energies for Be, LiH, H 2 O, and BH are computed through a primal-dual interior-point algorithm for positive semidefinite programming. The variational method produces potential-energy surfaces that are highly accurate even far from the equilibrium geometry where single-reference perturbation-based methods often fail to produce realistic energies
Gibbs-Thomson Law for Singular Step Segments: Thermodynamics Versus Kinetics
Chernov, A. A.
2003-01-01
Classical Burton-Cabrera-Frank theory presumes that thermal fluctuations are so fast that at any time density of kinks on a step is comparable with the reciprocal intermolecular distance, so that the step rate is about isotropic within the crystal plane. Such azimuthal isotropy is, however, often not the case: Kink density may be much lower. In particular, it was recently found on the (010) face of orthorhombic lysozyme that interkink distance may exceed 500-600 intermolecular distances. Under such conditions, Gibbs-Thomson law (GTL) may not be applicable: On a straight step segment between two corners, communication between the comers occurs exclusively by kink exchange. Annihilation between kinks of opposite sign generated at the comers results in the grain in step energy entering GTL. If the step segment length l much greater than D/v, where D and v are the kink diffusivity and propagation rate, respectively, the opposite kinks have practically no chance to annihilate and GTL is not applicable. The opposite condition of the GTL applicability, l much less than D/v, is equivalent to the requirement that relative supersaturation Delta(sub mu)/kT much less than alpha/l, where alpha is molecular size. Thus, GTL may be applied to a segment of 10(exp 3)alpha approx. 3 x 10(exp -5)cm approx 0.3 micron only if supersaturation is less than 0.1%, while practically used driving forces for crystallization are much larger. Relationships alternative to the GTL for different, but low, kink density have been discussed. They confirm experimental evidences that the Burton-Cabrera-Frank theory of spiral growth is growth rates twice as low as compared to the observed figures. Also, application of GTL results in unrealistic step energy while suggested kinetic law give reasonable figures.
Directory of Open Access Journals (Sweden)
R. Feistel
2005-01-01
Full Text Available The 2003 Gibbs thermodynamic potential function represents a very accurate, compact, consistent and comprehensive formulation of equilibrium properties of seawater. It is expressed in the International Temperature Scale ITS-90 and is fully consistent with the current scientific pure water standard, IAPWS-95. Source code examples in FORTRAN, C++ and Visual Basic are presented for the numerical implementation of the potential function and its partial derivatives, as well as for potential temperature. A collection of thermodynamic formulas and relations is given for possible applications in oceanography, from density and chemical potential over entropy and potential density to mixing heat and entropy production. For colligative properties like vapour pressure, freezing points, and for a Gibbs potential of sea ice, the equations relating the Gibbs function of seawater to those of vapour and ice are presented.
Numerical implementation and oceanographic application of the Gibbs potential of ice
Directory of Open Access Journals (Sweden)
R. Feistel
2005-01-01
Full Text Available The 2004 Gibbs thermodynamic potential function of naturally abundant water ice is based on much more experimental data than its predecessors, is therefore significantly more accurate and reliable, and for the first time describes the entire temperature and pressure range of existence of this ice phase. It is expressed in the ITS-90 temperature scale and is consistent with the current scientific pure water standard, IAPWS-95, and the 2003 Gibbs potential of seawater. The combination of these formulations provides sublimation pressures, freezing points, and sea ice properties covering the parameter ranges of oceanographic interest. This paper provides source code examples in Visual Basic, Fortran and C++ for the computation of the Gibbs function of ice and its partial derivatives. It reports the most important related thermodynamic equations for ice and sea ice properties.
Beattle, A J; Oliver, I
1994-12-01
Biological surveys are in increasing demand while taxonomic resources continue to decline. How much formal taxonomy is required to get the job done? The answer depends on the kind of job but it is possible that taxonomic minimalism, especially (1) the use of higher taxonomic ranks, (2) the use of morphospecies rather than species (as identified by Latin binomials), and (3) the involvement of taxonomic specialists only for training and verification, may offer advantages for biodiversity assessment, environmental monitoring and ecological research. As such, formal taxonomy remains central to the process of biological inventory and survey but resources may be allocated more efficiently. For example, if formal Identification is not required, resources may be concentrated on replication and increasing sample sizes. Taxonomic minimalism may also facilitate the inclusion in these activities of important but neglected groups, especially among the invertebrates, and perhaps even microorganisms. Copyright © 1994. Published by Elsevier Ltd.
Existence and uniqueness of Gibbs states for a statistical mechanical polyacetylene model
International Nuclear Information System (INIS)
Park, Y.M.
1987-01-01
One-dimensional polyacetylene is studied as a model of statistical mechanics. In a semiclassical approximation the system is equivalent to a quantum XY model interacting with unbounded classical spins in one-dimensional lattice space Z. By establishing uniform estimates, an infinite-volume-limit Hilbert space, a strongly continuous time evolution group of unitary operators, and an invariant vector are constructed. Moreover, it is proven that any infinite-limit state satisfies Gibbs conditions. Finally, a modification of Araki's relative entropy method is used to establish the uniqueness of Gibbs states
Improved prediction of MHC class I and class II epitopes using a novel Gibbs sampling approach
DEFF Research Database (Denmark)
Nielsen, Morten; Lundegaard, Claus; Worning, Peder
2004-01-01
Prediction of which peptides will bind a specific major histocompatibility complex (MHC) constitutes an important step in identifying potential T-cell epitopes suitable as vaccine candidates. MHC class II binding peptides have a broad length distribution complicating such predictions. Thus......, identifying the correct alignment is a crucial part of identifying the core of an MHC class II binding motif. In this context, we wish to describe a novel Gibbs motif sampler method ideally suited for recognizing such weak sequence motifs. The method is based on the Gibbs sampling method, and it incorporates...
International Nuclear Information System (INIS)
Nema, Pragya; Rangnekar, Saroj; Nema, R.K.
2010-01-01
Cellular mobile service is a rapidly expanding and a very competitive business worldwide, including developing countries. This paper proposes that the suitable alternative solution of grid power is the stand-alone PV/wind hybrid energy system with diesel generator as a backup for cellular mobile telephony base station site in isolated areas. It is expected that the newly developed and installed system would provide very good opportunities for mobile telephony base station in near future. In addition, protecting the environment and combating climate change are two of the most pressing challenges facing humankind. As energy prices soar, network operators are increasingly scrutinizing their environmental and social responsibilities. This system will be more cost effective and environmental friendly over the conventional diesel generator. Approximately 70-80% fuel cost over conventional diesel generator and the emission of CO 2 and other harmful gasses in environments were reduced. (author)
Jones, Jo; Jackson, Janet; Tudor, Terry; Bates, Margaret
2012-09-01
Strategies for enhancing environmental management are a key focus for the government in the UK. Using a manufacturing company from the construction sector as a case study, this paper evaluates selected interventionist techniques, including environmental teams, awareness raising and staff training to improve environmental performance. The study employed a range of methods including questionnaire surveys and audits of energy consumption and generation of waste to examine the outcomes of the selected techniques. The results suggest that initially environmental management was not a focus for either the employees or the company. However, as a result of employing the techniques, the company was able to reduce energy consumption, increase recycling rates and achieve costs savings in excess of £132,000.
Energy Technology Data Exchange (ETDEWEB)
Bergdahl, B G; Liao, B; Sieurin, J [EuroSim AB, Nykoeping (Sweden)
1996-05-01
A Decision Support System to reduce NO{sub x} emission from combustion processes with SNCR system have been developed and tested in full scale at Oerebro Energy. The boiler is a 165 MWh{sub th} CFB and have been fired with a mixture of biomass, peat and coal. The results proves that the EuroSim method works to calculate the derivative included in the Decision Support System. The Decision Support System is a tool for the operator of the plant, he will be informed of the advantage of making an increase or decrease of the ammonia flow or excess air. The trend curves that are presented to the operator includes information about the economic value to make an adjustment of the ammonia flow. The derivative dNO{sub x}/dO{sub 2} shows the advantage of making a reduction in the excess air level, concerning the fee for NO{sub x}. In this case it is important to take into consideration the risk for understoichiometric combustion and corrosion. The results from the full scale test in the Oerebro Plant shows that during some time periods it is economical to shut off the ammonia flow. The derivative dNO{sub x}/dAF is under the profitability limit. This indicate that the cost for the ammonia is higher than the fee for the NO{sub x} emission. If the ammonia flow is added in excess, the emission of ammonia and N{sub 2}O will increase. During other time periods the Decision Support System shows that it is profitable to increase the ammonia flow, the derivative is lower than -0,2. The derivative dNO{sub x}/dO{sub 2} is normally between 10 and 20 (ppm/%). This indicate that it is a great potential to reduce the NO{sub x} fee by decreasing the excess air level in the boiler. 3 refs, 23 figs
DEFF Research Database (Denmark)
Rodek, L.; Knudsen, E.; Poulsen, H.F.
2005-01-01
discrete tomographic algorithm, applying image-modelling Gibbs priors and a homogeneity condition. The optimization of the objective function is accomplished via the Gibbs Sampler in conjunction with simulated annealing. In order to express the structure of the orientation map, the similarity...
Experimental Pragmatics and What Is Said: A Response to Gibbs and Moise.
Nicolle, Steve; Clark, Billy
1999-01-01
Attempted replication of Gibbs and Moise (1997) experiments regarding the recognition of a distinction between what is said and what is implicated. Results showed that, under certain conditions, subject selected implicatures when asked to select the paraphrase best reflecting what a speaker has said. Suggests that results can be explained with the…
Uniqueness of Gibbs states and global Markov property for Euclidean fields
International Nuclear Information System (INIS)
Albeverio, S.; Hoeegh-Krohn, R.
1981-01-01
The authors briefly discuss the proof of the uniqueness of solutions of the DLR equations (uniqueness of Gibbs states) in the class of regular generalized random fields (in the sense of having second moments bounded by those of some Euclidean field), for the Euclidean fields with trigonometric interaction. (Auth.)
Fast covariance estimation for innovations computed from a spatial Gibbs point process
DEFF Research Database (Denmark)
Coeurjolly, Jean-Francois; Rubak, Ege
In this paper, we derive an exact formula for the covariance of two innovations computed from a spatial Gibbs point process and suggest a fast method for estimating this covariance. We show how this methodology can be used to estimate the asymptotic covariance matrix of the maximum pseudo...
DEFF Research Database (Denmark)
Wang, Haijiao; Chen, Zhe; Jiang, Quanyuan
2015-01-01
This study proposes an optimal control method for variable speed wind turbines (VSWTs) based wind farm (WF) to support temporary primary frequency control. This control method consists of two layers: temporary frequency support control (TFSC) of the VSWT, and temporary support power optimal...... dispatch (TSPOD) of the WF. With TFSC, the VSWT could temporarily provide extra power to support system frequency under varying and wide-range wind speed. In the WF control centre, TSPOD optimally dispatches the frequency support power orders to the VSWTs that operate under different wind speeds, minimises...... the wind energy cost of frequency support, and satisfies the support capabilities of the VSWTs. The effectiveness of the whole control method is verified in the IEEE-RTS built in MATLABSimulink, and compared with a published de-loading method....
Directory of Open Access Journals (Sweden)
Shanshan He
2015-10-01
Full Text Available Piecewise linear (G01-based tool paths generated by CAM systems lack G1 and G2 continuity. The discontinuity causes vibration and unnecessary hesitation during machining. To ensure efficient high-speed machining, a method to improve the continuity of the tool paths is required, such as B-spline fitting that approximates G01 paths with B-spline curves. Conventional B-spline fitting approaches cannot be directly used for tool path B-spline fitting, because they have shortages such as numerical instability, lack of chord error constraint, and lack of assurance of a usable result. Progressive and Iterative Approximation for Least Squares (LSPIA is an efficient method for data fitting that solves the numerical instability problem. However, it does not consider chord errors and needs more work to ensure ironclad results for commercial applications. In this paper, we use LSPIA method incorporating Energy term (ELSPIA to avoid the numerical instability, and lower chord errors by using stretching energy term. We implement several algorithm improvements, including (1 an improved technique for initial control point determination over Dominant Point Method, (2 an algorithm that updates foot point parameters as needed, (3 analysis of the degrees of freedom of control points to insert new control points only when needed, (4 chord error refinement using a similar ELSPIA method with the above enhancements. The proposed approach can generate a shape-preserving B-spline curve. Experiments with data analysis and machining tests are presented for verification of quality and efficiency. Comparisons with other known solutions are included to evaluate the worthiness of the proposed solution.
On P-Adic Quasi Gibbs Measures for Q + 1-State Potts Model on the Cayley Tree
International Nuclear Information System (INIS)
Mukhamedov, Farrukh
2010-06-01
In the present paper we introduce a new class of p-adic measures, associated with q +1-state Potts model, called p-adic quasi Gibbs measure, which is totally different from the p-adic Gibbs measure. We establish the existence p-adic quasi Gibbs measures for the model on a Cayley tree. If q is divisible by p, then we prove the occurrence of a strong phase transition. If q and p are relatively prime, then there is a quasi phase transition. These results are totally different from the results of [F.M.Mukhamedov, U.A. Rozikov, Indag. Math. N.S. 15(2005) 85-100], since q is divisible by p, which means that q + 1 is not divided by p, so according to a main result of the mentioned paper, there is a unique and bounded p-adic Gibbs measure (different from p-adic quasi Gibbs measure). (author)
He, Ping
2012-01-01
The long-standing puzzle surrounding the statistical mechanics of self-gravitating systems has not yet been solved successfully. We formulate a systematic theoretical framework of entropy-based statistical mechanics for spherically symmetric collisionless self-gravitating systems. We use an approach that is very different from that of the conventional statistical mechanics of short-range interaction systems. We demonstrate that the equilibrium states of self-gravitating systems consist of both mechanical and statistical equilibria, with the former characterized by a series of velocity-moment equations and the latter by statistical equilibrium equations, which should be derived from the entropy principle. The velocity-moment equations of all orders are derived from the steady-state collisionless Boltzmann equation. We point out that the ergodicity is invalid for the whole self-gravitating system, but it can be re-established locally. Based on the local ergodicity, using Fermi-Dirac-like statistics, with the non-degenerate condition and the spatial independence of the local microstates, we rederive the Boltzmann-Gibbs entropy. This is consistent with the validity of the collisionless Boltzmann equation, and should be the correct entropy form for collisionless self-gravitating systems. Apart from the usual constraints of mass and energy conservation, we demonstrate that the series of moment or virialization equations must be included as additional constraints on the entropy functional when performing the variational calculus; this is an extension to the original prescription by White & Narayan. Any possible velocity distribution can be produced by the statistical-mechanical approach that we have developed with the extended Boltzmann-Gibbs/White-Narayan statistics. Finally, we discuss the questions of negative specific heat and ensemble inequivalence for self-gravitating systems.
International Nuclear Information System (INIS)
Singh, R.N.; Stahle, P.; Sairam, K.; Ristmana, Matti; Banerjee, S.
2008-01-01
The objective of the present investigation is to predict the habit plane of δ-hydride precipitating in α-Zr at 25 and 300 deg C using strain energy minimization technique. The δ-hydride phase is modeled to undergo isotropic elastic and plastic deformation. The α-Zr phase was modeled to undergo transverse isotropic elastic deformation. Both isotropic plastic and transverse isotropic plastic deformations of α-Zr were considered. Further, both perfect and linear work-hardening plastic behaviors of zirconium and its hydride were considered. Accommodation strain energy of δ-hydrides forming in α-Zr crystal was computed using initial strain method as a function of hydride nuclei orientation. Hydride was modeled as disk with circular edge. The simulation was carried out using materials properties reported at 25 and 300 deg C. Contrary to several habit planes reported in literature for δ-hydrides precipitating in α-Zr crystal the total accommodation energy minima suggests only basal plane i.e. (0001) as the habit plane. (author)
International Nuclear Information System (INIS)
Nie, S.; Li, Y.P.; Liu, J.; Huang, Charley Z.
2017-01-01
An interval-stochastic risk management (ISRM) method is launched to control the variability of the recourse cost as well as to capture the notion of risk in stochastic programming. The ISRM method can examine various policy scenarios that are associated with economic penalties under uncertainties presented as probability distributions and interval values. An ISRM model is then formulated to identify the optimal power mix for the Beijing's energy system. Tradeoffs between risk and cost are evaluated, indicating any change in targeted cost and risk level would yield different expected costs. Results reveal that the inherent uncertainty of system components and risk attitude of decision makers have significant effects on the city's energy-supply and electricity-generation schemes as well as system cost and probabilistic penalty. Results also disclose that import electricity as a recourse action to compensate the local shortage would be enforced. The import electricity would increase with a reduced risk level; under every risk level, more electricity would be imported with an increased demand. The findings can facilitate the local authority in identifying desired strategies for the city's energy planning and management in association with financial-cost minimization and environmental-impact mitigation. - Highlights: • Interval-stochastic risk management method is launched to identify optimal power mix. • It is advantageous in capturing the notion of risk in stochastic programming. • Results reveal that risk attitudes can affect optimal power mix and financial cost. • Developing renewable energies would enhance the sustainability of energy management. • Import electricity as an action to compensate the local shortage would be enforced.
International Nuclear Information System (INIS)
Thompson, P.
1991-01-01
This article discusses ways to reduce the economic risk of independent energy projects. The topics of the article include risk categorization into areas of property, boiler and machinery, business income, and general liability, choosing a broker, choosing an insurer, and helping an insurer develop the best portfolio for the project. The author feels that attention to the guidelines for the right insurance coverage is as vital to a plant's economic stability as attention to the details of the blueprints is to its physical stability
Energy Technology Data Exchange (ETDEWEB)
Bloch, Claude; Dominicis, Cyrano de [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Saclay, Gif-sur-Yvette (France)
1959-07-01
Starting from an expansion derived in a previous work, we study the contribution to the Gibbs potential of the two-body dynamical correlations, taking into account the statistical correlations. Such a contribution is of interest for low density systems at low temperature. In the zero density limit, it reduces to the Beth Uhlenbeck expression of the second virial coefficient. For a system of fermions in the zero temperature limit, it yields the contribution of the Brueckner reaction matrix to the ground state energy, plus, under certain conditions, additional terms of the form exp. (β |Δ|), where the Δ are the binding energies of 'bound states' of the type first discussed by L. Cooper. Finally, we study the wave function of two particles immersed in a medium (defined by its temperature and chemical potential). lt satisfies an equation generalizing the Bethe Goldstone equation for an arbitrary temperature. Reprint of a paper published in 'Nuclear Physics' 10, 1959, p. 181-196 [French] Partant d'un developpement extrait d'un precedent travail, nous etudions la contribution au potentiel de Gibbs des relations dynamiques du systeme de deux corps, en tenant compte des relations statistiques. Une telle contribution presente de l'interet pour les systemes a densite faible et a basse temperature. A la densite limite zero, elle se ramene a l'expression de Beth Uhlenbeck du second coefficient virial. Pour un systeme de fermions a la temperature limite zero, il produit la contribution de la matrice de reaction de Brueckner au niveau fondamental, plus, dans certaines conditions, des termes additionnels de la forme exp. (β |Δ|), ou les Δ sont les energies de liaison des 'etats lies' du premier type, discutes auparavant par L. Cooper. Finalement, on etudie la fonction d'onde de deux particules immerges dans un milieu (definie par sa temperature et son potentiel chimique). Il satisfait a une equation generalisant l'equation de Bethe Goldstone pour une temperature arbitraire
Simultaneous alignment and clustering of peptide data using a Gibbs sampling approach
DEFF Research Database (Denmark)
Andreatta, Massimo; Lund, Ole; Nielsen, Morten
2013-01-01
Motivation: Proteins recognizing short peptide fragments play a central role in cellular signaling. As a result of high-throughput technologies, peptide-binding protein specificities can be studied using large peptide libraries at dramatically lower cost and time. Interpretation of such large...... peptide datasets, however, is a complex task, especially when the data contain multiple receptor binding motifs, and/or the motifs are found at different locations within distinct peptides.Results: The algorithm presented in this article, based on Gibbs sampling, identifies multiple specificities...... of unaligned peptide datasets of variable length. Example applications described in this article include mixtures of binders to different MHC class I and class II alleles, distinct classes of ligands for SH3 domains and sub-specificities of the HLA-A*02:01 molecule.Availability: The Gibbs clustering method...
Uniqueness of Gibbs measure for Potts model with countable set of spin values
International Nuclear Information System (INIS)
Ganikhodjaev, N.N.; Rozikov, U.A.
2004-11-01
We consider a nearest-neighbor Potts model with countable spin values 0,1,..., and non zero external field, on a Cayley tree of order k (with k+1 neighbors). We study translation-invariant 'splitting' Gibbs measures. We reduce the problem to the description of the solutions of some infinite system of equations. For any k≥1 and any fixed probability measure ν with ν(i)>0 on the set of all non negative integer numbers Φ={0,1,...} we show that the set of translation-invariant splitting Gibbs measures contains at most one point, independently on parameters of the Potts model with countable set of spin values on Cayley tree. Also we give a full description of the class of measures ν on Φ such that wit respect to each element of this class our infinite system of equations has unique solution {a i =1,2,...}, where a is an element of (0,1). (author)
Inverse problems with non-trivial priors: efficient solution through sequential Gibbs sampling
DEFF Research Database (Denmark)
Hansen, Thomas Mejer; Cordua, Knud Skou; Mosegaard, Klaus
2012-01-01
Markov chain Monte Carlo methods such as the Gibbs sampler and the Metropolis algorithm can be used to sample solutions to non-linear inverse problems. In principle, these methods allow incorporation of prior information of arbitrary complexity. If an analytical closed form description of the prior...... is available, which is the case when the prior can be described by a multidimensional Gaussian distribution, such prior information can easily be considered. In reality, prior information is often more complex than can be described by the Gaussian model, and no closed form expression of the prior can be given....... We propose an algorithm, called sequential Gibbs sampling, allowing the Metropolis algorithm to efficiently incorporate complex priors into the solution of an inverse problem, also for the case where no closed form description of the prior exists. First, we lay out the theoretical background...
Entropy Calculation of Reversible Mixing of Ideal Gases Shows Absence of Gibbs Paradox
Directory of Open Access Journals (Sweden)
Oleg Borodiouk
1999-05-01
Full Text Available Abstract: We consider the work of reversible mixing of ideal gases using a real process. Now assumptions were made concerning infinite shifts, infinite number of cycles and infinite work to provide an accurate calculation of entropy resulting from reversible mixing of ideal gases. We derived an equation showing the dependence of this entropy on the difference in potential of mixed gases, which is evidence for the absence of Gibbs' paradox.
Entropy Calculation of Reversible Mixing of Ideal Gases Shows Absence of Gibbs Paradox
Oleg Borodiouk; Vasili Tatarin
1999-01-01
Abstract: We consider the work of reversible mixing of ideal gases using a real process. Now assumptions were made concerning infinite shifts, infinite number of cycles and infinite work to provide an accurate calculation of entropy resulting from reversible mixing of ideal gases. We derived an equation showing the dependence of this entropy on the difference in potential of mixed gases, which is evidence for the absence of Gibbs' paradox.
DEFF Research Database (Denmark)
Hansen, Thomas Mejer; Mosegaard, Klaus; Cordua, Knud Skou
2010-01-01
Markov chain Monte Carlo methods such as the Gibbs sampler and the Metropolis algorithm can be used to sample the solutions to non-linear inverse problems. In principle these methods allow incorporation of arbitrarily complex a priori information, but current methods allow only relatively simple...... this algorithm with the Metropolis algorithm to obtain an efficient method for sampling posterior probability densities for nonlinear inverse problems....
International Nuclear Information System (INIS)
Lin, Shu-Kun
1996-01-01
Gibbs paradox statement of entropy of mixing has been regarded as the theoretical foundation of statistical mechanics, quantum theory and biophysics. However, all the relevant chemical experimental observations and logical analyses indicate that the Gibbs paradox statement is false. I prove that this statement is wrong: Gibbs paradox statement implies that entropy decreases with the increase in symmetry (as represented by a symmetry number σ; see any statistical mechanics textbook). From group theory any system has at least a symmetry number σ=1 which is the identity operation for a strictly asymmetric system. It follows that the entropy of a system is equal to, or less than, zero. However, from either von Neumann-Shannon entropy formula (S(w) =-Σ ω in p 1 ) or the Boltzmann entropy formula (S = in w) and the original definition, entropy is non-negative. Therefore, this statement is false. It should not be a surprise that for the first time, many outstanding problems such as the validity of Pauling's resonance theory, the explanation of second order phase transition phenomena, the biophysical problem of protein folding and the related hydrophobic effect, etc., can be solved. Empirical principles such as Pauli principle (and Hund's rule) and HSAB principle, etc., can also be given a theoretical explanation
Nan, Ning; Chen, Qi; Wang, Yu; Zhai, Xu; Yang, Chuan-Ce; Cao, Bin; Chong, Tie
2017-10-01
To explore the disturbed molecular functions and pathways in clear cell renal cell carcinoma (ccRCC) using Gibbs sampling. Gene expression data of ccRCC samples and adjacent non-tumor renal tissues were recruited from public available database. Then, molecular functions of expression changed genes in ccRCC were classed to Gene Ontology (GO) project, and these molecular functions were converted into Markov chains. Markov chain Monte Carlo (MCMC) algorithm was implemented to perform posterior inference and identify probability distributions of molecular functions in Gibbs sampling. Differentially expressed molecular functions were selected under posterior value more than 0.95, and genes with the appeared times in differentially expressed molecular functions ≥5 were defined as pivotal genes. Functional analysis was employed to explore the pathways of pivotal genes and their strongly co-regulated genes. In this work, we obtained 396 molecular functions, and 13 of them were differentially expressed. Oxidoreductase activity showed the highest posterior value. Gene composition analysis identified 79 pivotal genes, and survival analysis indicated that these pivotal genes could be used as a strong independent predictor of poor prognosis in patients with ccRCC. Pathway analysis identified one pivotal pathway - oxidative phosphorylation. We identified the differentially expressed molecular functions and pivotal pathway in ccRCC using Gibbs sampling. The results could be considered as potential signatures for early detection and therapy of ccRCC. Copyright © 2017 Elsevier Ltd. All rights reserved.
The Gibbs-Thomson equation for a spherical coherent precipitate with applications to nucleation
International Nuclear Information System (INIS)
Rottman, C.; Voorhees, P.W.; Johnson, W.C.
1988-01-01
The conditions for interfacial thermodynamic equilibrium form the basis for the derivation of a number of basic equations in materials science, including the various forms of the Gibbs-Thomson equation. The equilibrium conditions pertaining to a curved interface in a two-phase fluid system are well-known. In contrast, the conditions for thermodynamic equilibrium at a curved interface in nonhydrostatically stressed solids have only recently been examined. These conditions can be much different from those at a fluid interface and, as a result, the Gibbs-Thomson equation appropriate to coherent solids is likely to be considerably different from that for fluids. In this paper, the authors first derive the conditions necessary for thermodynamic equilibrium at the precipitate-matrix interface of a coherent spherical precipitate. The authors' derivation of these equilibrium conditions includes a correction to the equilibrium conditions of Johnson and Alexander for a spherical precipitate in an isotropic matrix. They then use these conditions to derive the dependence of the interfacial precipitate and matrix concentrations on precipitate radius (Gibbs-Thomson equation) for a such a precipitate. In addition, these relationships are then used to calculate the critical radius for the nucleation of a coherent misfitting precipitate
Energy Technology Data Exchange (ETDEWEB)
Fallone, B; Keyvanloo, A; Burke, B; St Aubin, J; Baillie, D; Wachowicz, K; Warkentin, B; Steciw, S [Cross Cancer Institute, Edmonton, AB (Canada)
2016-06-15
Purpose: To quantify increase in entrance skin-dose due to magnetic fields of the Alberta longitudinal linac-MR by examining the effect of radiation energy and flattening filter, using Monte Carlo calculations and accurate 3-D models of the magnetic field. Methods: The 3-D magnetic fields generated by the bi-planar Linac-MR are calculated with FEM using Opera-3D. BEAMnrc simulates the particle phase-space in the presence of the rapidly decaying fringe field of 0.5T MRI assembled with a Varian 600C linac with an isocentre distance of 130 cm for 6 MV and 10 MV beams. Skin doses are calculated at an average depth of 70 µm using DOSXYZnrc with varying SSDs and field sizes. Furthermore, flattening filters are reshaped to compensate for the significant drop in dose rate due to increased SAD of 130 cm and skin-doses are evaluated. Results: The confinement effect of the MRI fringe field on the contaminant electrons is minimal. For SSDs of 100 – 120 cm the increase in skin dose is ∼6% – 19% and ∼1% – 9% for the 6 and 10 MV beams, respectively. For 6MV, skin dose increases from ∼10.5% to 1.5%. for field-size increases of 5×5 cm2 to 20×20 cm2. For 10 MV, skin dose increases by ∼6% for a 5×5 cm2 field, and decreases by ∼1.5% for a 20×20 cm2 field. The reshaped flattening filter increases the dose rate from 355 MU/min to 529 MU/min (6 MV) or 604 MU/min (10 MV), while the skin-dose increases by only an additional ∼2.6% (all percent increases in skin dose are relative to Dmax). Conclusion: There is minimal increase in the entrance skin dose and minimal/no decrease in the dose rate of the Alberta longitudinal linac-MR system. There is even lower skin-dose increase at 10 MV. Funding: Alberta Innovates - Health Solutions (AIHS) Conflict of Interest: Fallone is a co-founder and CEO of MagnetTx Oncology Solutions (under discussions to license Alberta bi-planar linac MR for commercialization)
DEFF Research Database (Denmark)
Foadi, Roshan; Frandsen, Mads Toudal; A. Ryttov, T.
2007-01-01
Different theoretical and phenomenological aspects of the Minimal and Nonminimal Walking Technicolor theories have recently been studied. The goal here is to make the models ready for collider phenomenology. We do this by constructing the low energy effective theory containing scalars......, pseudoscalars, vector mesons and other fields predicted by the minimal walking theory. We construct their self-interactions and interactions with standard model fields. Using the Weinberg sum rules, opportunely modified to take into account the walking behavior of the underlying gauge theory, we find...... interesting relations for the spin-one spectrum. We derive the electroweak parameters using the newly constructed effective theory and compare the results with the underlying gauge theory. Our analysis is sufficiently general such that the resulting model can be used to represent a generic walking technicolor...
Monte, M J S; Almeida, A R R P; Liebman, J F
2015-11-01
Halogenated benzenes form a class of pollutants with a huge number of members - 1504 distinct benzene compounds, where one or more hydrogen atoms are replaced by halogens, may exist theoretically. This study presents a user friendly method for accurate prediction of vapor pressures and enthalpies of vaporization, at 298.15 K, of any mono or poly halobenzene compound. The derived equations for the prediction of those vaporization properties depend just on the number of each constituent halogen atom. This is a consequence of the absence of intramolecular interactions between the halogen atoms, revealed after examining vaporization results of ca. 40 halogenated benzenes. In order to rationalize the estimation equations, the contribution of the halogen atoms for the referred to above properties of vaporization was decomposed into two atomic properties - the volume and electron affinity. Extension of the applicability of the estimation method to substituted benzenes containing other substituent groups beyond halogen atoms as well as to some polycyclic aromatic species was tested with success. Copyright © 2015 Elsevier Ltd. All rights reserved.
Kyriakis, Efstathios; Psomopoulos, Constantinos; Kokkotis, Panagiotis; Bourtsalas, Athanasios; Themelis, Nikolaos
2017-06-23
This study attempts the development of an algorithm in order to present a step by step selection method for the location and the size of a waste-to-energy facility targeting the maximum output energy, also considering the basic obstacle which is in many cases, the gate fee. Various parameters identified and evaluated in order to formulate the proposed decision making method in the form of an algorithm. The principle simulation input is the amount of municipal solid wastes (MSW) available for incineration and along with its net calorific value are the most important factors for the feasibility of the plant. Moreover, the research is focused both on the parameters that could increase the energy production and those that affect the R1 energy efficiency factor. Estimation of the final gate fee is achieved through the economic analysis of the entire project by investigating both expenses and revenues which are expected according to the selected site and outputs of the facility. In this point, a number of commonly revenue methods were included in the algorithm. The developed algorithm has been validated using three case studies in Greece-Athens, Thessaloniki, and Central Greece, where the cities of Larisa and Volos have been selected for the application of the proposed decision making tool. These case studies were selected based on a previous publication made by two of the authors, in which these areas where examined. Results reveal that the development of a «solid» methodological approach in selecting the site and the size of waste-to-energy (WtE) facility can be feasible. However, the maximization of the energy efficiency factor R1 requires high utilization factors while the minimization of the final gate fee requires high R1 and high metals recovery from the bottom ash as well as economic exploitation of recovered raw materials if any.
Zoeal morphology of Pachygrapsus transversus (Gibbes (Decapoda, Grapsidae reared in the laboratory
Directory of Open Access Journals (Sweden)
Ana Luiza Brossi-Garcia
1997-12-01
Full Text Available Ovigerous females of Pachygrapsus transversus (Gibbes, 1850 were collected on the Praia Dura and Saco da Ribeira beaches, Ubatuba, São Paulo, Brazil. Larvae were individually reared in a climatic room at 25ºC temperature, salinities of 28, 32 and 35‰ and under natural photoperiod conditions. The best rearing results were observed at 35%o salinity. Seven zoeal instars were observed, drawing and described in detail. The data are compared with those obtained for P. gracilis (Saussure, 1858.
ASTEM, Evaluation of Gibbs, Helmholtz and Saturation Line Function for Thermodynamics Calculation
International Nuclear Information System (INIS)
Moore, K.V.; Burgess, M.P.; Fuller, G.L.; Kaiser, A.H.; Jaeger, D.L.
1974-01-01
1 - Description of problem or function: ASTEM is a modular set of FORTRAN IV subroutines to evaluate the Gibbs, Helmholtz, and saturation line functions as published by the American Society of Mechanical Engineers (1967). Any thermodynamic quantity including derivative properties can be obtained from these routines by a user-supplied main program. PROPS is an auxiliary routine available for the IBM360 version which makes it easier to apply the ASTEM routines to power station models. 2 - Restrictions on the complexity of the problem: Unless re-dimensioned by the user, the highest derivative allowed is order 9. All arrays within ASTEM are one-dimensional to save storage area
LA CASA GIBBS Y EL MONOPOLIO SALITRERO PERUANO: 1876-1878
Directory of Open Access Journals (Sweden)
Manuel Ravest Mora
2008-06-01
Full Text Available El objeto de este breve trabajo es mostrar la disposición de Anthony Gibbs & Sons, y de sus filiales, a apoyar el proyecto monopólico salitrero del Perú con recursos monetarios y los manejos de sus directores en la única empresa que, dada su capacidad de elaboración, podía hacerlo fracasar: la Compañía de Salitres y Ferrocarril de Antofagasta, de la que Gibbs era el segundo mayor accionista. Para el gobierno chileno la causa primaria de la guerra de 1879 fue el intento del Perú por monopolizar la producción salitrera. Bolivia, su aliada secreta desde 1873, colaboró arrendándole y vendiéndole sus depósitos de nitrato, e imponiendo a la exportación del salitre un tributo que infringió la condición -estipulada en un Tratado de Límites- bajo la cual Chile le cedió territorio. Su recuperación manu militari inició el conflicto. A partir de la segunda mitad del siglo pasado esta tesis economicista-legalista fue cuestionada en Chile y en el exterior, desplazando el acento causal al reordenamiento de los mercados de materias primas -de las que los beligerantes eran exportadores- a consecuencia de la crisis mundial de la década de 1870.This brief study aims at showing Anthony Gibbs & Sons disposition in supporting the Peruvian monopolistic nitrate project with monetary resources and its Director's influences in the only company which, due its production's capacity, could make the project fail: the Chilean Antofagasta Nitrate and Railway Co. in which Gibbs was the second most important stockholder. According to Chilean government the primary cause of 1879's war was Peru's attempt to monopolize nitrate production. Bolivia, its secret allied since 1873, helped renting and selling him her nitrate fields and imposing a tax on the nitrate exports of the Chilean company in Antofagasta, thus violating the condition stated in a Border Treaty by which Chile had ceded territory. Its recovery through the use of military forcé was the first act
The minimally tuned minimal supersymmetric standard model
International Nuclear Information System (INIS)
Essig, Rouven; Fortin, Jean-Francois
2008-01-01
The regions in the Minimal Supersymmetric Standard Model with the minimal amount of fine-tuning of electroweak symmetry breaking are presented for general messenger scale. No a priori relations among the soft supersymmetry breaking parameters are assumed and fine-tuning is minimized with respect to all the important parameters which affect electroweak symmetry breaking. The superpartner spectra in the minimally tuned region of parameter space are quite distinctive with large stop mixing at the low scale and negative squark soft masses at the high scale. The minimal amount of tuning increases enormously for a Higgs mass beyond roughly 120 GeV
Monte Carlo Molecular Simulation with Isobaric-Isothermal and Gibbs-NPT Ensembles
Du, Shouhong
2012-01-01
This thesis presents Monte Carlo methods for simulations of phase behaviors of Lennard-Jones fluids. The isobaric-isothermal (NPT) ensemble and Gibbs-NPT ensemble are introduced in detail. NPT ensemble is employed to determine the phase diagram of pure component. The reduced simulation results are verified by comparison with the equation of state by by Johnson et al. and results with L-J parameters of methane agree considerably with the experiment measurements. We adopt the blocking method for variance estimation and error analysis of the simulation results. The relationship between variance and number of Monte Carlo cycles, error propagation and Random Number Generator performance are also investigated. We review the Gibbs-NPT ensemble employed for phase equilibrium of binary mixture. The phase equilibrium is achieved by performing three types of trial move: particle displacement, volume rearrangement and particle transfer. The simulation models and the simulation details are introduced. The simulation results of phase coexistence for methane and ethane are reported with comparison of the experimental data. Good agreement is found for a wide range of pressures. The contribution of this thesis work lies in the study of the error analysis with respect to the Monte Carlo cycles and number of particles in some interesting aspects.
Gibbs Measures Over Locally Tree-Like Graphs and Percolative Entropy Over Infinite Regular Trees
Austin, Tim; Podder, Moumanti
2018-03-01
Consider a statistical physical model on the d-regular infinite tree Td described by a set of interactions Φ . Let Gn be a sequence of finite graphs with vertex sets V_n that locally converge to Td. From Φ one can construct a sequence of corresponding models on the graphs G_n. Let μ_n be the resulting Gibbs measures. Here we assume that μ n converges to some limiting Gibbs measure μ on Td in the local weak^* sense, and study the consequences of this convergence for the specific entropies |V_n|^{-1}H(μ _n). We show that the limit supremum of |V_n|^{-1}H(μ _n) is bounded above by the percolative entropy H_{it{perc}}(μ ), a function of μ itself, and that |V_n|^{-1}H(μ _n) actually converges to H_{it{perc}}(μ ) in case Φ exhibits strong spatial mixing on T_d. When it is known to exist, the limit of |V_n|^{-1}H(μ _n) is most commonly shown to be given by the Bethe ansatz. Percolative entropy gives a different formula, and we do not know how to connect it to the Bethe ansatz directly. We discuss a few examples of well-known models for which the latter result holds in the high temperature regime.
Monte Carlo Molecular Simulation with Isobaric-Isothermal and Gibbs-NPT Ensembles
Du, Shouhong
2012-05-01
This thesis presents Monte Carlo methods for simulations of phase behaviors of Lennard-Jones fluids. The isobaric-isothermal (NPT) ensemble and Gibbs-NPT ensemble are introduced in detail. NPT ensemble is employed to determine the phase diagram of pure component. The reduced simulation results are verified by comparison with the equation of state by by Johnson et al. and results with L-J parameters of methane agree considerably with the experiment measurements. We adopt the blocking method for variance estimation and error analysis of the simulation results. The relationship between variance and number of Monte Carlo cycles, error propagation and Random Number Generator performance are also investigated. We review the Gibbs-NPT ensemble employed for phase equilibrium of binary mixture. The phase equilibrium is achieved by performing three types of trial move: particle displacement, volume rearrangement and particle transfer. The simulation models and the simulation details are introduced. The simulation results of phase coexistence for methane and ethane are reported with comparison of the experimental data. Good agreement is found for a wide range of pressures. The contribution of this thesis work lies in the study of the error analysis with respect to the Monte Carlo cycles and number of particles in some interesting aspects.
International Nuclear Information System (INIS)
Chan, M.T.; Herman, G.T.; Levitan, E.
1996-01-01
We demonstrate that (i) classical methods of image reconstruction from projections can be improved upon by considering the output of such a method as a distorted version of the original image and applying a Bayesian approach to estimate from it the original image (based on a model of distortion and on a Gibbs distribution as the prior) and (ii) by selecting an open-quotes image-modelingclose quotes prior distribution (i.e., one which is such that it is likely that a random sample from it shares important characteristics of the images of the application area) one can improve over another Gibbs prior formulated using only pairwise interactions. We illustrate our approach using simulated Positron Emission Tomography (PET) data from realistic brain phantoms. Since algorithm performance ultimately depends on the diagnostic task being performed. we examine a number of different medically relevant figures of merit to give a fair comparison. Based on a training-and-testing evaluation strategy, we demonstrate that statistically significant improvements can be obtained using the proposed approach
Directory of Open Access Journals (Sweden)
Sovilj P.
2014-10-01
Full Text Available Measurement methods, based on the approach named Digital Stochastic Measurement, have been introduced, and several prototype and small-series commercial instruments have been developed based on these methods. These methods have been mostly investigated for various types of stationary signals, but also for non-stationary signals. This paper presents, analyzes and discusses digital stochastic measurement of electroencephalography (EEG signal in the time domain, emphasizing the problem of influence of the Wilbraham-Gibbs phenomenon. The increase of measurement error, related to the Wilbraham-Gibbs phenomenon, is found. If the EEG signal is measured and measurement interval is 20 ms wide, the average maximal error relative to the range of input signal is 16.84 %. If the measurement interval is extended to 2s, the average maximal error relative to the range of input signal is significantly lowered - down to 1.37 %. Absolute errors are compared with the error limit recommended by Organisation Internationale de Métrologie Légale (OIML and with the quantization steps of the advanced EEG instruments with 24-bit A/D conversion
Toher, Cormac; Oses, Corey; Plata, Jose J.; Hicks, David; Rose, Frisco; Levy, Ohad; de Jong, Maarten; Asta, Mark; Fornari, Marco; Buongiorno Nardelli, Marco; Curtarolo, Stefano
2017-06-01
Thorough characterization of the thermomechanical properties of materials requires difficult and time-consuming experiments. This severely limits the availability of data and is one of the main obstacles for the development of effective accelerated materials design strategies. The rapid screening of new potential materials requires highly integrated, sophisticated, and robust computational approaches. We tackled the challenge by developing an automated, integrated workflow with robust error-correction within the AFLOW framework which combines the newly developed "Automatic Elasticity Library" with the previously implemented GIBBS method. The first extracts the mechanical properties from automatic self-consistent stress-strain calculations, while the latter employs those mechanical properties to evaluate the thermodynamics within the Debye model. This new thermoelastic workflow is benchmarked against a set of 74 experimentally characterized systems to pinpoint a robust computational methodology for the evaluation of bulk and shear moduli, Poisson ratios, Debye temperatures, Grüneisen parameters, and thermal conductivities of a wide variety of materials. The effect of different choices of equations of state and exchange-correlation functionals is examined and the optimum combination of properties for the Leibfried-Schlömann prediction of thermal conductivity is identified, leading to improved agreement with experimental results than the GIBBS-only approach. The framework has been applied to the AFLOW.org data repositories to compute the thermoelastic properties of over 3500 unique materials. The results are now available online by using an expanded version of the REST-API described in the Appendix.
Annual Waste Minimization Summary Report
International Nuclear Information System (INIS)
Haworth, D.M.
2011-01-01
This report summarizes the waste minimization efforts undertaken by National Security TechnoIogies, LLC, for the U. S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO), during calendar year 2010. The NNSA/NSO Pollution Prevention Program establishes a process to reduce the volume and toxicity of waste generated by NNSA/NSO activities and ensures that proposed methods of treatment, storage, and/or disposal of waste minimize potential threats to human health and the environment.
The minimal non-minimal standard model
International Nuclear Information System (INIS)
Bij, J.J. van der
2006-01-01
In this Letter I discuss a class of extensions of the standard model that have a minimal number of possible parameters, but can in principle explain dark matter and inflation. It is pointed out that the so-called new minimal standard model contains a large number of parameters that can be put to zero, without affecting the renormalizability of the model. With the extra restrictions one might call it the minimal (new) non-minimal standard model (MNMSM). A few hidden discrete variables are present. It is argued that the inflaton should be higher-dimensional. Experimental consequences for the LHC and the ILC are discussed
Calculation of the surface free energy of fcc copper nanoparticles
International Nuclear Information System (INIS)
Jia Ming; Lai Yanqing; Tian Zhongliang; Liu Yexiang
2009-01-01
Using molecular dynamics simulations with the modified analytic embedded-atom method we calculate the Gibbs free energy and surface free energy for fcc Cu bulk, and further obtain the Gibbs free energy of nanoparticles. Based on the Gibbs free energy of nanoparticles, we have investigated the heat capacity of copper nanoparticles. Calculation results indicate that the Gibbs free energy and the heat capacity of nanoparticles can be divided into two parts: bulk quantity and surface quantity. The molar heat capacity of the bulk sample is lower compared with the molar heat capacity of nanoparticles, and this difference increases with the decrease in the particle size. It is also observed that the size effect on the thermodynamic properties of Cu nanoparticles is not really significant until the particle is less than about 20 nm. It is the surface atoms that decide the size effect on the thermodynamic properties of nanoparticles
Dynamics of macro-observables and space-time inhomogeneous Gibbs ensembles
International Nuclear Information System (INIS)
Lanz, L.; Lupieri, G.
1978-01-01
The relationship between the classical description of a macro-system and quantum mechanics of its particles is considered within the framework recently developed by Ludwig. A procedure is given to define probability measures on the trajectory space of a macrosystem which yields a statistical description of the dynamics of a macrosystem. The basic tool in this treatment is a new concept of space-time inhomogeneous Gibbs ensemble, defined in N-body quantum mechanics. In the Gaussian approximation of the probabilities the results of Zubarev's theory based on the ''nonequilibrium statistical operator'' are recovered. The present ''embedding'' of the description of a macrosystem inside the N-body theory allows for a joint description of a macrosystem and a microsubsystem of it, and a ''macroscopical'' calculation of the statistical operator of the microsystem is indicated. (author)
The osmotic second virial coefficient and the Gibbs-McMillan-Mayer framework
DEFF Research Database (Denmark)
Mollerup, J.M.; Breil, Martin Peter
2009-01-01
The osmotic second virial coefficient is a key parameter in light scattering, protein crystallisation. self-interaction chromatography, and osmometry. The interpretation of the osmotic second virial coefficient depends on the set of independent variables. This commonly includes the independent...... variables associated with the Kirkwood-Buff, the McMillan-Mayer, and the Lewis-Randall solution theories. In this paper we analyse the osmotic second virial coefficient using a Gibbs-McMillan-Mayer framework which is similar to the McMillan-Mayer framework with the exception that pressure rather than volume...... is an independent variable. A Taylor expansion is applied to the osmotic pressure of a solution where one of the solutes is a small molecule, a salt for instance, that equilibrates between the two phases. Other solutes are retained. Solvents are small molecules that equilibrate between the two phases...
A course on large deviations with an introduction to Gibbs measures
Rassoul-Agha, Firas
2015-01-01
This is an introductory course on the methods of computing asymptotics of probabilities of rare events: the theory of large deviations. The book combines large deviation theory with basic statistical mechanics, namely Gibbs measures with their variational characterization and the phase transition of the Ising model, in a text intended for a one semester or quarter course. The book begins with a straightforward approach to the key ideas and results of large deviation theory in the context of independent identically distributed random variables. This includes Cramér's theorem, relative entropy, Sanov's theorem, process level large deviations, convex duality, and change of measure arguments. Dependence is introduced through the interactions potentials of equilibrium statistical mechanics. The phase transition of the Ising model is proved in two different ways: first in the classical way with the Peierls argument, Dobrushin's uniqueness condition, and correlation inequalities and then a second time through the ...
Scan Order in Gibbs Sampling: Models in Which it Matters and Bounds on How Much.
He, Bryan; De Sa, Christopher; Mitliagkas, Ioannis; Ré, Christopher
2016-01-01
Gibbs sampling is a Markov Chain Monte Carlo sampling technique that iteratively samples variables from their conditional distributions. There are two common scan orders for the variables: random scan and systematic scan. Due to the benefits of locality in hardware, systematic scan is commonly used, even though most statistical guarantees are only for random scan. While it has been conjectured that the mixing times of random scan and systematic scan do not differ by more than a logarithmic factor, we show by counterexample that this is not the case, and we prove that that the mixing times do not differ by more than a polynomial factor under mild conditions. To prove these relative bounds, we introduce a method of augmenting the state space to study systematic scan using conductance.
Ergodic time-reversible chaos for Gibbs' canonical oscillator
International Nuclear Information System (INIS)
Hoover, William Graham; Sprott, Julien Clinton; Patra, Puneet Kumar
2015-01-01
Nosé's pioneering 1984 work inspired a variety of time-reversible deterministic thermostats. Though several groups have developed successful doubly-thermostated models, single-thermostat models have failed to generate Gibbs' canonical distribution for the one-dimensional harmonic oscillator. A 2001 doubly-thermostated model, claimed to be ergodic, has a singly-thermostated version. Though neither of these models is ergodic this work has suggested a successful route toward singly-thermostated ergodicity. We illustrate both ergodicity and its lack for these models using phase-space cross sections and Lyapunov instability as diagnostic tools. - Highlights: • We develop cross-section and Lyapunov methods for diagnosing ergodicity. • We apply these methods to several thermostatted-oscillator problems. • We demonstrate the nonergodicity of previous work. • We find a novel family of ergodic thermostatted-oscillator problems.
Directory of Open Access Journals (Sweden)
Chaeyoung Lee
2012-11-01
Full Text Available Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.
Gu, Jinghua; Xuan, Jianhua; Riggins, Rebecca B; Chen, Li; Wang, Yue; Clarke, Robert
2012-08-01
Identification of transcriptional regulatory networks (TRNs) is of significant importance in computational biology for cancer research, providing a critical building block to unravel disease pathways. However, existing methods for TRN identification suffer from the inclusion of excessive 'noise' in microarray data and false-positives in binding data, especially when applied to human tumor-derived cell line studies. More robust methods that can counteract the imperfection of data sources are therefore needed for reliable identification of TRNs in this context. In this article, we propose to establish a link between the quality of one target gene to represent its regulator and the uncertainty of its expression to represent other target genes. Specifically, an outlier sum statistic was used to measure the aggregated evidence for regulation events between target genes and their corresponding transcription factors. A Gibbs sampling method was then developed to estimate the marginal distribution of the outlier sum statistic, hence, to uncover underlying regulatory relationships. To evaluate the effectiveness of our proposed method, we compared its performance with that of an existing sampling-based method using both simulation data and yeast cell cycle data. The experimental results show that our method consistently outperforms the competing method in different settings of signal-to-noise ratio and network topology, indicating its robustness for biological applications. Finally, we applied our method to breast cancer cell line data and demonstrated its ability to extract biologically meaningful regulatory modules related to estrogen signaling and action in breast cancer. The Gibbs sampler MATLAB package is freely available at http://www.cbil.ece.vt.edu/software.htm. xuan@vt.edu Supplementary data are available at Bioinformatics online.
Czech Academy of Sciences Publication Activity Database
Moučka, F.; Nezbeda, Ivo
2013-01-01
Roč. 360, DEC 25 (2013), s. 472-476 ISSN 0378-3812 Grant - others:GA MŠMT(CZ) LH12019 Institutional support: RVO:67985858 Keywords : multi-particle move monte carlo * Gibbs ensemble * vapor-liquid-equilibria Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.241, year: 2013
Ebenhöh, Oliver; Spelberg, Stephanie
2018-02-19
The photosynthetic carbon reduction cycle, or Calvin-Benson-Bassham (CBB) cycle, is now contained in every standard biochemistry textbook. Although the cycle was already proposed in 1954, it is still the subject of intense research, and even the structure of the cycle, i.e. the exact series of reactions, is still under debate. The controversy about the cycle's structure was fuelled by the findings of Gibbs and Kandler in 1956 and 1957, when they observed that radioactive 14 CO 2 was dynamically incorporated in hexoses in a very atypical and asymmetrical way, a phenomenon later termed the 'photosynthetic Gibbs effect'. Now, it is widely accepted that the photosynthetic Gibbs effect is not in contradiction to the reaction scheme proposed by CBB, but the arguments given have been largely qualitative and hand-waving. To fully appreciate the controversy and to understand the difficulties in interpreting the Gibbs effect, it is illustrative to illuminate the history of the discovery of the CBB cycle. We here give an account of central scientific advances and discoveries, which were essential prerequisites for the elucidation of the cycle. Placing the historic discoveries in the context of the modern textbook pathway scheme illustrates the complexity of the cycle and demonstrates why especially dynamic labelling experiments are far from easy to interpret. We conclude by arguing that it requires sound theoretical approaches to resolve conflicting interpretations and to provide consistent quantitative explanations. © 2018 The Author(s).
Rigorous force field optimization principles based on statistical distance minimization
Energy Technology Data Exchange (ETDEWEB)
Vlcek, Lukas, E-mail: vlcekl1@ornl.gov [Chemical Sciences Division, Geochemistry & Interfacial Sciences Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110 (United States); Joint Institute for Computational Sciences, University of Tennessee, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6173 (United States); Chialvo, Ariel A. [Chemical Sciences Division, Geochemistry & Interfacial Sciences Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110 (United States)
2015-10-14
We use the concept of statistical distance to define a measure of distinguishability between a pair of statistical mechanical systems, i.e., a model and its target, and show that its minimization leads to general convergence of the model’s static measurable properties to those of the target. We exploit this feature to define a rigorous basis for the development of accurate and robust effective molecular force fields that are inherently compatible with coarse-grained experimental data. The new model optimization principles and their efficient implementation are illustrated through selected examples, whose outcome demonstrates the higher robustness and predictive accuracy of the approach compared to other currently used methods, such as force matching and relative entropy minimization. We also discuss relations between the newly developed principles and established thermodynamic concepts, which include the Gibbs-Bogoliubov inequality and the thermodynamic length.
Feng, Dong-xia; Nguyen, Anh V
2016-03-01
Floating objects on the air-water interfaces are central to a number of everyday activities, from walking on water by insects to flotation separation of valuable minerals using air bubbles. The available theories show that a fine sphere can float if the force of surface tension and buoyancies can support the sphere at the interface with an apical angle subtended by the circle of contact being larger than the contact angle. Here we show that the pinning of the contact line at the sharp edge, known as the Gibbs inequality condition, also plays a significant role in controlling the stability and detachment of floating spheres. Specifically, we truncated the spheres with different angles and used a force sensor device to measure the force of pushing the truncated spheres from the interface into water. We also developed a theoretical modeling to calculate the pushing force that in combination with experimental results shows different effects of the Gibbs inequality condition on the stability and detachment of the spheres from the water surface. For small angles of truncation, the Gibbs inequality condition does not affect the sphere detachment, and hence the classical theories on the floatability of spheres are valid. For large truncated angles, the Gibbs inequality condition determines the tenacity of the particle-meniscus contact and the stability and detachment of floating spheres. In this case, the classical theories on the floatability of spheres are no longer valid. A critical truncated angle for the transition from the classical to the Gibbs inequality regimes of detachment was also established. The outcomes of this research advance our understanding of the behavior of floating objects, in particular, the flotation separation of valuable minerals, which often contain various sharp edges of their crystal faces.
DEFF Research Database (Denmark)
Gobalasingham, Nemal S.; Carlé, Jon Eggert; Krebs, Frederik C
2017-01-01
of high-performance materials. To demonstrate the usefulness of the method, DArP-prepared PPDTBT via continuous flow synthesis is employed for the preparation of indium tin oxide (ITO)-free and flexible roll-coated solar cells to achieve a power conversion efficiency of 3.5% for 1 cm2 devices, which...... is comparable to the performance of PPDTBT polymerized through Stille cross coupling. These efforts demonstrate the distinct advantages of the continuous flow protocol with DArP avoiding use of toxic tin chemicals, reducing the associated costs of polymer upscaling, and minimizing batch-to-batch variations...
Wang, Ke-Dong; Wang, Mei-Ting; Meng, Ju
2014-10-01
Allowing for all combinations of internal single-bond rotamers, 1,296 unique trial structures of γ-Aminobutyric acid (GABA) are obtained. All of these structures are optimized at the M06-2X level of theory and a total of 68 local minimal conformers are found. The nine low-lying conformers are used for further studies. According to the calculated relative Gibbs free energies at M06-2X level of theory, we find that the dispersion is important for the relative energy of GABA. The intramolecular hydrogen bonds and hyperconjugative interaction and their effects on the conformational stability are studied. The results show that both of them have great influence on the conformers. The vertical ionization energies (VIE) are calculated and match the experimental data well. The results show that the neutral GABA in the gas phase is a multi-conformer system and at least four conformations exist.
Regularity of Minimal Surfaces
Dierkes, Ulrich; Tromba, Anthony J; Kuster, Albrecht
2010-01-01
"Regularity of Minimal Surfaces" begins with a survey of minimal surfaces with free boundaries. Following this, the basic results concerning the boundary behaviour of minimal surfaces and H-surfaces with fixed or free boundaries are studied. In particular, the asymptotic expansions at interior and boundary branch points are derived, leading to general Gauss-Bonnet formulas. Furthermore, gradient estimates and asymptotic expansions for minimal surfaces with only piecewise smooth boundaries are obtained. One of the main features of free boundary value problems for minimal surfaces is t
Gobalasingham, Nemal S; Carlé, Jon E; Krebs, Frederik C; Thompson, Barry C; Bundgaard, Eva; Helgesen, Martin
2017-11-01
Continuous flow methods are utilized in conjunction with direct arylation polymerization (DArP) for the scaled synthesis of the roll-to-roll compatible polymer, poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(4,7-di(thiophen-2-yl)-benzo[c][1,2,5]thiadiazole)] (PPDTBT). PPDTBT is based on simple, inexpensive, and scalable monomers using thienyl-flanked benzothiadiazole as the acceptor, which is the first β-unprotected substrate to be used in continuous flow via DArP, enabling critical evaluation of the suitability of this emerging synthetic method for minimizing defects and for the scaled synthesis of high-performance materials. To demonstrate the usefulness of the method, DArP-prepared PPDTBT via continuous flow synthesis is employed for the preparation of indium tin oxide (ITO)-free and flexible roll-coated solar cells to achieve a power conversion efficiency of 3.5% for 1 cm 2 devices, which is comparable to the performance of PPDTBT polymerized through Stille cross coupling. These efforts demonstrate the distinct advantages of the continuous flow protocol with DArP avoiding use of toxic tin chemicals, reducing the associated costs of polymer upscaling, and minimizing batch-to-batch variations for high-quality material. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
International Nuclear Information System (INIS)
Mohr, M.; Skiba, M.; Gernhardt, D.; Ziolek, A.; Unger, H.
1994-07-01
The Tenth Technical Report of the study 'Analysis of Possibilities of Solar Power Supply and its Development in Nordrhein-Westfalen' contains a catalogue of recommended steps for the introduction of renewable energy systems into the existing energy supply structure in NRW. First, strategies for least cost renewable energy supply systems are developed and applied to modelled municipalities in such a way, that a cost optimized mix of renewable energies, depending on the desired degree of 'renewable coverage', can be given for each model community. Analogous to that, a low cost CO 2 -reduction strategy by an aimed extension of renewable energy systems is calculated and represented. The legal skeleton conditions of the power supply, information and training deficits as well as transmitted behavior patterns, which counteract an integration of renewable energy systems, are discussed in view of 'non economical' obstacles also. A catalogue of measures is presented, which contains informational, organizational and especially administrative aspects, including possibilities for governmental support. These recommendations may be used by those responsible for political decisions, i.e. by municipal planners, local or regional power suppliers and - last but not least - private consumers. (orig.) [de
Limit order book and its modeling in terms of Gibbs Grand-Canonical Ensemble
Bicci, Alberto
2016-12-01
In the domain of so called Econophysics some attempts have been already made for applying the theory of thermodynamics and statistical mechanics to economics and financial markets. In this paper a similar approach is made from a different perspective, trying to model the limit order book and price formation process of a given stock by the Grand-Canonical Gibbs Ensemble for the bid and ask orders. The application of the Bose-Einstein statistics to this ensemble allows then to derive the distribution of the sell and buy orders as a function of price. As a consequence we can define in a meaningful way expressions for the temperatures of the ensembles of bid orders and of ask orders, which are a function of minimum bid, maximum ask and closure prices of the stock as well as of the exchanged volume of shares. It is demonstrated that the difference between the ask and bid orders temperatures can be related to the VAO (Volume Accumulation Oscillator), an indicator empirically defined in Technical Analysis of stock markets. Furthermore the derived distributions for aggregate bid and ask orders can be subject to well defined validations against real data, giving a falsifiable character to the model.
Demonstration and resolution of the Gibbs paradox of the first kind
International Nuclear Information System (INIS)
Peters, Hjalmar
2014-01-01
The Gibbs paradox of the first kind (GP1) refers to the false increase in entropy which, in statistical mechanics, is calculated from the process of combining two gas systems S1 and S2 consisting of distinguishable particles. Presented in a somewhat modified form, the GP1 manifests as a contradiction to the second law of thermodynamics. Contrary to popular belief, this contradiction affects not only classical but also quantum statistical mechanics. This paper resolves the GP1 by considering two effects. (i) The uncertainty about which particles are located in S1 and which in S2 contributes to the entropies of S1 and S2. (ii) S1 and S2 are correlated by the fact that if a certain particle is located in one system, it cannot be located in the other. As a consequence, the entropy of the total system consisting of S1 and S2 is not the sum of the entropies of S1 and S2. (paper)
Ahmad, Mohd Ali Khameini; Liao, Lingmin; Saburov, Mansoor
2018-06-01
We study the set of p-adic Gibbs measures of the q-state Potts model on the Cayley tree of order three. We prove the vastness of the set of the periodic p-adic Gibbs measures for such model by showing the chaotic behavior of the corresponding Potts-Bethe mapping over Q_p for the prime numbers p≡1 (mod 3). In fact, for 0< |θ -1|_p< |q|_p^2 < 1 where θ =\\exp _p(J) and J is a coupling constant, there exists a subsystem that is isometrically conjugate to the full shift on three symbols. Meanwhile, for 0< |q|_p^2 ≤ |θ -1|_p< |q|_p < 1, there exists a subsystem that is isometrically conjugate to a subshift of finite type on r symbols where r ≥ 4. However, these subshifts on r symbols are all topologically conjugate to the full shift on three symbols. The p-adic Gibbs measures of the same model for the prime numbers p=2,3 and the corresponding Potts-Bethe mapping are also discussed. On the other hand, for 0< |θ -1|_p< |q|_p < 1, we remark that the Potts-Bethe mapping is not chaotic when p=3 and p≡ 2 (mod 3) and we could not conclude the vastness of the set of the periodic p-adic Gibbs measures. In a forthcoming paper with the same title, we will treat the case 0< |q|_p ≤ |θ -1|_p < 1 for all prime numbers p.
Minimally invasive orthognathic surgery.
Resnick, Cory M; Kaban, Leonard B; Troulis, Maria J
2009-02-01
Minimally invasive surgery is defined as the discipline in which operative procedures are performed in novel ways to diminish the sequelae of standard surgical dissections. The goals of minimally invasive surgery are to reduce tissue trauma and to minimize bleeding, edema, and injury, thereby improving the rate and quality of healing. In orthognathic surgery, there are two minimally invasive techniques that can be used separately or in combination: (1) endoscopic exposure and (2) distraction osteogenesis. This article describes the historical developments of the fields of orthognathic surgery and minimally invasive surgery, as well as the integration of the two disciplines. Indications, techniques, and the most current outcome data for specific minimally invasive orthognathic surgical procedures are presented.
Leck, Kira
2006-10-01
Researchers have associated minimal dating with numerous factors. The present author tested shyness, introversion, physical attractiveness, performance evaluation, anxiety, social skill, social self-esteem, and loneliness to determine the nature of their relationships with 2 measures of self-reported minimal dating in a sample of 175 college students. For women, shyness, introversion, physical attractiveness, self-rated anxiety, social self-esteem, and loneliness correlated with 1 or both measures of minimal dating. For men, physical attractiveness, observer-rated social skill, social self-esteem, and loneliness correlated with 1 or both measures of minimal dating. The patterns of relationships were not identical for the 2 indicators of minimal dating, indicating the possibility that minimal dating is not a single construct as researchers previously believed. The present author discussed implications and suggestions for future researchers.
Hexavalent Chromium Minimization Strategy
2011-05-01
Logistics 4 Initiative - DoD Hexavalent Chromium Minimization Non- Chrome Primer IIEXAVAJ ENT CHRO:M I~UMI CHROMIUM (VII Oil CrfVli.J CANCEfl HAnRD CD...Management Office of the Secretary of Defense Hexavalent Chromium Minimization Strategy Report Documentation Page Form ApprovedOMB No. 0704-0188...00-2011 4. TITLE AND SUBTITLE Hexavalent Chromium Minimization Strategy 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6
DEFF Research Database (Denmark)
Antola, M.; Di Chiara, S.; Sannino, F.
2011-01-01
We introduce novel extensions of the Standard Model featuring a supersymmetric technicolor sector (supertechnicolor). As the first minimal conformal supertechnicolor model we consider N=4 Super Yang-Mills which breaks to N=1 via the electroweak interactions. This is a well defined, economical......, between unparticle physics and Minimal Walking Technicolor. We consider also other N =1 extensions of the Minimal Walking Technicolor model. The new models allow all the standard model matter fields to acquire a mass....
International Nuclear Information System (INIS)
Bergshoeff, Eric; Merbis, Wout; Hohm, Olaf; Routh, Alasdair J; Townsend, Paul K
2014-01-01
We present an alternative to topologically massive gravity (TMG) with the same ‘minimal’ bulk properties; i.e. a single local degree of freedom that is realized as a massive graviton in linearization about an anti-de Sitter (AdS) vacuum. However, in contrast to TMG, the new ‘minimal massive gravity’ has both a positive energy graviton and positive central charges for the asymptotic AdS-boundary conformal algebra. (paper)
DEFF Research Database (Denmark)
2010-01-01
Disclosed herein are techniques, systems, and methods relating to minimizing mutual coupling between a first antenna and a second antenna.......Disclosed herein are techniques, systems, and methods relating to minimizing mutual coupling between a first antenna and a second antenna....
Ruled Laguerre minimal surfaces
Skopenkov, Mikhail; Pottmann, Helmut; Grohs, Philipp
2011-01-01
A Laguerre minimal surface is an immersed surface in ℝ 3 being an extremal of the functional ∫ (H 2/K-1)dA. In the present paper, we prove that the only ruled Laguerre minimal surfaces are up to isometry the surfaces ℝ (φλ) = (Aφ, Bφ, Cφ + D cos 2φ
Serrao, Mariano; Chini, Giorgia; Iosa, Marco; Casali, Carlo; Morone, Giovanni; Conte, Carmela; Bini, Fabiano; Marinozzi, Franco; Coppola, Gianluca; Pierelli, Francesco; Draicchio, Francesco; Ranavolo, Alberto
2017-10-01
The harmony of the human gait was recently found to be related to the golden ratio value (ϕ). The ratio between the duration of the stance and that of the swing phases of a gait cycle was in fact found to be close to ϕ, which implies that, because of the fractal property of autosimilarity of that number, the gait ratios stride/stance, stance/swing, swing/double support, were not significantly different from one another. We studied a group of patients with cerebellar ataxia to investigate how the differences between their gait ratios and the golden ratio are related to efficiency and stability of their gait, assessed by energy expenditure and stride-to-stride variability, respectively. The gait of 28 patients who were affected by degenerative cerebellar ataxia and of 28 healthy controls was studied using a stereophotogrammetric system. The above mentioned gait ratios, the energy expenditure estimated using the pelvis reconstructed method and the gait variability in terms of the stride length were computed, and their relationships were analyzed. Matching procedures have also been used to avoid multicollinearity biases. The gait ratio values of the patients were farther from the controls (and hence from ϕ), even in speed matched conditions (P=0.011, Cohen's D=0.76), but not when the variability and energy expenditure were matched between the two groups (Cohen's D=0.49). In patients with cerebellar ataxia, the farther the stance-swing ratio was from ϕ, the larger the total mechanical work (R 2 adj =0.64). Further, a significant positive correlation was observed between the difference of the gait ratio from the golden ratio and the severity of the disease (R=0.421, P=0.026). Harmony of gait appears to be a benchmark of physiological gait leading to physiological energy recovery and gait reliability. Neurorehabilitation of patients with ataxia might benefit from the restoration of harmony of their locomotor patterns. Copyright © 2017. Published by Elsevier Ltd.
International Nuclear Information System (INIS)
2008-01-01
The petroleum industry is now in the process of determining which methods and technologies will be adopted to reduce the environmental impacts caused by emissions. This forum investigated methods of increasing efficiency and reducing greenhouses gas (GHG) emissions in oil sands operations. Industry operators, government official and researchers discussed new approaches to addressing climatic change. Provincial energy efficiency policies were discussed, and cost-effective methods for increasing the energy efficiency of oil sands processing plants were reviewed. GHG credit programs were discussed. New technologies for reducing fugitive emissions and recovering energy from waste heat were presented. Water-friendly steam assisted gravity drainage (SAGD) projects were outlined, and new distributed generation plans for oil and gas processing plants were presented. Pollutant emission control technologies were discussed. The conference also included several presentations that examined the development of carbon capture and storage (CCS) technologies and the construction of pipeline infrastructure. Sequestration technologies and sites were also reviewed. The forum featured 24 presentations, of which 3 have been catalogued separately for inclusion in this database. tabs., figs
International Nuclear Information System (INIS)
Contillo, Adriano; Di Domenico, Giovanni; Cardarelli, Paolo; Gambaccini, Mauro; Taibi, Angelo
2016-01-01
Purpose: Dual-energy image subtraction represents a useful tool to improve the detectability of small lesions, especially in dense breasts. A feature it shares with all x-ray imaging techniques is the appearance of fluctuations in the texture of the background, which can obscure the visibility of interesting details. The aim of the work is to investigate the main noise sources, in order to create a better performing subtraction mechanism. In particular, the structural noise cancellation was achieved by means of a suitable extension of the dual-energy algorithm. Methods: The effect of the cancellation procedure was tested on an analytical simulation of a target with varying structural composition. Subsequently, the subtraction algorithm was also applied to a set of actual radiographs of a breast phantom exhibiting a nonuniform background pattern. The background power spectra of the outcomes were computed and compared to the ones obtained from a standard subtraction algorithm. Results: The comparison between the standard and the proposed cancellations showed an overall suppression of the magnitudes of the spectra, as well as a flattening of the frequency dependence of the structural component of the noise. Conclusions: The proposed subtraction procedure provides an effective cancellation of the residual background fluctuations. When combined with the polychromatic correction already described in a companion publication, it results in a high performing dual-energy subtraction scheme for commercial mammography units.
Energy Technology Data Exchange (ETDEWEB)
Contillo, Adriano, E-mail: contillo@fe.infn.it; Di Domenico, Giovanni; Cardarelli, Paolo; Gambaccini, Mauro; Taibi, Angelo [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via Saragat 1, I-44122 Ferrara (Italy)
2016-06-15
Purpose: Dual-energy image subtraction represents a useful tool to improve the detectability of small lesions, especially in dense breasts. A feature it shares with all x-ray imaging techniques is the appearance of fluctuations in the texture of the background, which can obscure the visibility of interesting details. The aim of the work is to investigate the main noise sources, in order to create a better performing subtraction mechanism. In particular, the structural noise cancellation was achieved by means of a suitable extension of the dual-energy algorithm. Methods: The effect of the cancellation procedure was tested on an analytical simulation of a target with varying structural composition. Subsequently, the subtraction algorithm was also applied to a set of actual radiographs of a breast phantom exhibiting a nonuniform background pattern. The background power spectra of the outcomes were computed and compared to the ones obtained from a standard subtraction algorithm. Results: The comparison between the standard and the proposed cancellations showed an overall suppression of the magnitudes of the spectra, as well as a flattening of the frequency dependence of the structural component of the noise. Conclusions: The proposed subtraction procedure provides an effective cancellation of the residual background fluctuations. When combined with the polychromatic correction already described in a companion publication, it results in a high performing dual-energy subtraction scheme for commercial mammography units.
The Charlie-Gibbs Fracture Zone: A Crossroads of the Atlantic Meridional Overturning Circulation
Bower, A. S.; Furey, H. H.; Xu, X.
2016-02-01
The Charlie-Gibbs Fracture Zone (CGFZ), a deep gap in the Mid-Atlantic Ridge at 52N, is the primary conduit for westward-flowing Iceland-Scotland Overflow Water (ISOW), which merges with Denmark Strait Overflow Water to form the Deep Western Boundary Current. The CGFZ has also been shown to "funnel" the path of the northern branch of the eastward-flowing North Atlantic Current (NAC), thereby bringing these two branches of the AMOC into close proximity. A recent two-year time series of hydrographic properties and currents from eight tall moorings across the CGFZ offers the first opportunity to investigate the NAC as a source of variability for ISOW transport. The two-year mean and standard deviation of ISOW transport was -1.7 ± 1.5 Sv, compared to -2.4 ± 3.0 Sv reported by Saunders for a 13-month period in 1988-1989. Differences in the two estimates are partly explained by limitations of the Saunders array, but more importantly reflect the strong low-frequency variability in ISOW transport through CGFZ (which includes complete reversals). Both the observations and output from a multi-decadal simulation of the North Atlantic using the Hybrid Coordinate Ocean Model (HYCOM) forced with interannually varying wind and buoyancy fields indicate a strong positive correlation between ISOW transport and the strength of the NAC through the CGFZ (stronger eastward NAC related to weaker westward ISOW transport). Vertical structure of the low-frequency current variability and water mass structure in the CGFZ will also be discussed. The results have implications regarding the interaction of the upper and lower limbs of the AMOC, and downstream propagation of ISOW transport variability in the Deep Western Boundary Current.
Modeling Electric Double-Layer Capacitors Using Charge Variation Methodology in Gibbs Ensemble
Directory of Open Access Journals (Sweden)
Ganeshprasad Pavaskar
2018-01-01
Full Text Available Supercapacitors deliver higher power than batteries and find applications in grid integration and electric vehicles. Recent work by Chmiola et al. (2006 has revealed unexpected increase in the capacitance of porous carbon electrodes using ionic liquids as electrolytes. The work has generated curiosity among both experimentalists and theoreticians. Here, we have performed molecular simulations using a recently developed technique (Punnathanam, 2014 for simulating supercapacitor system. In this technique, the two electrodes (containing electrolyte in slit pore are simulated in two different boxes using the Gibbs ensemble methodology. This reduces the number of particles required and interfacial interactions, which helps in reducing computational load. The method simulates an electric double-layer capacitor (EDLC with macroscopic electrodes with much smaller system sizes. In addition, the charges on individual electrode atoms are allowed to vary in response to movement of electrolyte ions (i.e., electrode is polarizable while ensuring these atoms are at the same electric potential. We also present the application of our technique on EDLCs with the electrodes modeled as slit pores and as complex three-dimensional pore networks for different electrolyte geometries. The smallest pore geometry showed an increase in capacitance toward the potential of 0 charge. This is in agreement with the new understanding of the electrical double layer in regions of dense ionic packing, as noted by Kornyshev’s theoretical model (Kornyshev, 2007, which also showed a similar trend. This is not addressed by the classical Gouy–Chapman theory for the electric double layer. Furthermore, the electrode polarizability simulated in the model improved the accuracy of the calculated capacitance. However, its addition did not significantly alter the capacitance values in the voltage range considered.
Modelling metal-humate interactions: an approach based on the Gibbs-Donnan concept
International Nuclear Information System (INIS)
Ephraim, J.H.
1995-01-01
Humic and fulvic acids constitute an appreciable portion of organic substances in both aquatic and terrestrial environments. Their ability to sequester metal ions and other trace elements has engaged the interest of numerous environmental scientists recently and even though considerable advances have been made, a lot more remains unknown in the area. The existence of high molecular weight fractions and functional group heterogeneity have endowed ion exchange characteristics to these substances. For example, the cation exchange capacities of some humic substances have been compared to those of smectites. Recent development in the solution chemistry has also indicated that humic substances have the capability to interact with other anions because of their amphiphilic nature. In this paper, metal-humate interaction is described by relying heavily on information obtained from treatment of the solution chemistry of ion exchangers as typical polymers. In such a treatment, the perturbations to the metal-humate interaction are estimated by resort to the Gibbs-Donnan concept where the humic substance molecule is envisaged as having a potential counter-ion concentrating region around its molecular domain into which diffusible components can enter or leave depending on their corresponding electrochemical potentials. Information from studies with ion exchangers have been adapted to describe ionic equilibria involving these substances by making it possible to characterise the configuration/conformation of these natural organic acids and to correct for electrostatic effects in the metal-humate interaction. The resultant unified physicochemical approach has facilitated the identification and estimation of the complications to the solution chemistry of humic substances. (authors). 15 refs., 1 fig
SUBLIMATION-DRIVEN ACTIVITY IN MAIN-BELT COMET 313P/GIBBS
Energy Technology Data Exchange (ETDEWEB)
Hsieh, Henry H. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Hainaut, Olivier [European Southern Observatory, Karl-Schwarzschild-Straße 2, D-85748 Garching bei München (Germany); Novaković, Bojan [Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade (Serbia); Bolin, Bryce [Observatoire de la Côte d’Azur, Boulevard de l’Observatoire, B.P. 4229, F-06304 Nice Cedex 4 (France); Denneau, Larry; Haghighipour, Nader; Kleyna, Jan; Meech, Karen J.; Schunova, Eva; Wainscoat, Richard J. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Fitzsimmons, Alan [Astrophysics Research Centre, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Kokotanekova, Rosita; Snodgrass, Colin [Planetary and Space Sciences, Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA (United Kingdom); Lacerda, Pedro [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Micheli, Marco [ESA SSA NEO Coordination Centre, Frascati, RM (Italy); Moskovitz, Nick; Wasserman, Lawrence [Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001 (United States); Waszczak, Adam, E-mail: hhsieh@asiaa.sinica.edu.tw [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)
2015-02-10
We present an observational and dynamical study of newly discovered main-belt comet 313P/Gibbs. We find that the object is clearly active both in observations obtained in 2014 and in precovery observations obtained in 2003 by the Sloan Digital Sky Survey, strongly suggesting that its activity is sublimation-driven. This conclusion is supported by a photometric analysis showing an increase in the total brightness of the comet over the 2014 observing period, and dust modeling results showing that the dust emission persists over at least three months during both active periods, where we find start dates for emission no later than 2003 July 24 ± 10 for the 2003 active period and 2014 July 28 ± 10 for the 2014 active period. From serendipitous observations by the Subaru Telescope in 2004 when the object was apparently inactive, we estimate that the nucleus has an absolute R-band magnitude of H{sub R} = 17.1 ± 0.3, corresponding to an effective nucleus radius of r{sub e} ∼ 1.00 ± 0.15 km. The object’s faintness at that time means we cannot rule out the presence of activity, and so this computed radius should be considered an upper limit. We find that 313P’s orbit is intrinsically chaotic, having a Lyapunov time of T{sub l} = 12,000 yr and being located near two three-body mean-motion resonances with Jupiter and Saturn, 11J-1S-5A and 10J+12S-7A, yet appears stable over >50 Myr in an apparent example of stable chaos. We furthermore find that 313P is the second main-belt comet, after P/2012 T1 (PANSTARRS), to belong to the ∼155 Myr old Lixiaohua asteroid family.
Energy Analysis in Combined Reforming of Propane
Directory of Open Access Journals (Sweden)
K. Moon
2013-01-01
Full Text Available Combined (steam and CO2 reforming is one of the methods to produce syngas for different applications. An energy requirement analysis of steam reforming to dry reforming with intermediate steps of steam reduction and equivalent CO2 addition to the feed fuel for syngas generation has been done to identify condition for optimum process operation. Thermodynamic equilibrium data for combined reforming was generated for temperature range of 400–1000°C at 1 bar pressure and combined oxidant (CO2 + H2O stream to propane (fuel ratio of 3, 6, and 9 by employing the Gibbs free energy minimization algorithm of HSC Chemistry software 5.1. Total energy requirement including preheating and reaction enthalpy calculations were done using the equilibrium product composition. Carbon and methane formation was significantly reduced in combined reforming than pure dry reforming, while the energy requirements were lower than pure steam reforming. Temperatures of minimum energy requirement were found in the data analysis of combined reforming which were optimum for the process.
Yin, K.; Belonoshko, A. B.; Zhou, H.; Lu, X.
2016-12-01
The melting temperatures of materials in the interior of the Earth has significant implications in many areas of geophysics. The direct calculations of the melting point by atomic simulations would face substantial hysteresis problem. To overcome the hysteresis encountered in the atomic simulations there are a few different melting-point determination methods available nowadays, which are founded independently, such as the free energy method, the two-phase or coexistence method, and the Z method, etc. In this study, we provide a theoretical understanding the relations of these methods from a geometrical perspective based on a quantitative construction of the volume-entropy-energy thermodynamic surface, a model first proposed by J. Willard Gibbs in 1873. Then combining with an experimental data and/or a previous melting-point determination method, we apply this model to derive the high-pressure melting curves for several lower mantle minerals with less computational efforts relative to using previous methods only. Through this way, some polyatomic minerals at extreme pressures which are almost unsolvable before are calculated fully from first principles now.
International Nuclear Information System (INIS)
BLOCH, Claude; DE DOMINICIS, Cyrano
1959-01-01
Starting from an expansion derived in a previous work, we study the contribution to the Gibbs potential of the two-body dynamical correlations, taking into account the statistical correlations. Such a contribution is of interest for low-density systems at low temperature. In the zero density limit, it reduces to the Beth-Uhlenbeck expression for the second virial coefficient. For a system of fermions in the zero temperature limit, it yields the contribution of the Brueckner reaction matrix to the ground state energy, plus, under certain conditions, additional terms of the form exp ( β / Δ /), where the Δ are the binding energies of 'bound states' of the type first discussed by L. Cooper. Finally, we study the wave function of two particles immersed in a medium (defined by its temperature and chemical potential). It satisfies an equation generalizing the Bethe-Goldstone equation for an arbitrary temperature. Reprint of a paper published in Nuclear Physics, 10, p. 509-526, 1959
Principle of minimal work fluctuations.
Xiao, Gaoyang; Gong, Jiangbin
2015-08-01
Understanding and manipulating work fluctuations in microscale and nanoscale systems are of both fundamental and practical interest. For example, in considering the Jarzynski equality 〈e-βW〉=e-βΔF, a change in the fluctuations of e-βW may impact how rapidly the statistical average of e-βW converges towards the theoretical value e-βΔF, where W is the work, β is the inverse temperature, and ΔF is the free energy difference between two equilibrium states. Motivated by our previous study aiming at the suppression of work fluctuations, here we obtain a principle of minimal work fluctuations. In brief, adiabatic processes as treated in quantum and classical adiabatic theorems yield the minimal fluctuations in e-βW. In the quantum domain, if a system initially prepared at thermal equilibrium is subjected to a work protocol but isolated from a bath during the time evolution, then a quantum adiabatic process without energy level crossing (or an assisted adiabatic process reaching the same final states as in a conventional adiabatic process) yields the minimal fluctuations in e-βW, where W is the quantum work defined by two energy measurements at the beginning and at the end of the process. In the classical domain where the classical work protocol is realizable by an adiabatic process, then the classical adiabatic process also yields the minimal fluctuations in e-βW. Numerical experiments based on a Landau-Zener process confirm our theory in the quantum domain, and our theory in the classical domain explains our previous numerical findings regarding the suppression of classical work fluctuations [G. Y. Xiao and J. B. Gong, Phys. Rev. E 90, 052132 (2014)].
; Environment Human Health Animal Health Safe Use Practices Food Safety Environment Air Water Soil Wildlife Home Page Pesticide Health and Safety Information Safe Use Practices Minimizing Exposure at Work Pesticides - Pennsylvania State University Cooperative Extension Personal Protective Equipment for Working
Hubbard, Guy
2002-01-01
Provides background information on the art movement called "Minimalism" discussing why it started and its characteristics. Includes learning activities and information on the artist, Donald Judd. Includes a reproduction of one of his art works and discusses its content. (CMK)
Ruled Laguerre minimal surfaces
Skopenkov, Mikhail
2011-10-30
A Laguerre minimal surface is an immersed surface in ℝ 3 being an extremal of the functional ∫ (H 2/K-1)dA. In the present paper, we prove that the only ruled Laguerre minimal surfaces are up to isometry the surfaces ℝ (φλ) = (Aφ, Bφ, Cφ + D cos 2φ) + λ(sin φ, cos φ, 0), where A,B,C,D ε ℝ are fixed. To achieve invariance under Laguerre transformations, we also derive all Laguerre minimal surfaces that are enveloped by a family of cones. The methodology is based on the isotropic model of Laguerre geometry. In this model a Laguerre minimal surface enveloped by a family of cones corresponds to a graph of a biharmonic function carrying a family of isotropic circles. We classify such functions by showing that the top view of the family of circles is a pencil. © 2011 Springer-Verlag.
Minimal and careful processing
Nielsen, Thorkild
2004-01-01
In several standards, guidelines and publications, organic food processing is strongly associated with "minimal processing" and "careful processing". The term "minimal processing" is nowadays often used in the general food processing industry and described in literature. The term "careful processing" is used more specifically within organic food processing but is not yet clearly defined. The concept of carefulness seems to fit very well with the processing of organic foods, especially if it i...
International Nuclear Information System (INIS)
Dinpajooh, Mohammadhasan; Bai, Peng; Allan, Douglas A.; Siepmann, J. Ilja
2015-01-01
Since the seminal paper by Panagiotopoulos [Mol. Phys. 61, 813 (1997)], the Gibbs ensemble Monte Carlo (GEMC) method has been the most popular particle-based simulation approach for the computation of vapor–liquid phase equilibria. However, the validity of GEMC simulations in the near-critical region has been questioned because rigorous finite-size scaling approaches cannot be applied to simulations with fluctuating volume. Valleau [Mol. Simul. 29, 627 (2003)] has argued that GEMC simulations would lead to a spurious overestimation of the critical temperature. More recently, Patel et al. [J. Chem. Phys. 134, 024101 (2011)] opined that the use of analytical tail corrections would be problematic in the near-critical region. To address these issues, we perform extensive GEMC simulations for Lennard-Jones particles in the near-critical region varying the system size, the overall system density, and the cutoff distance. For a system with N = 5500 particles, potential truncation at 8σ and analytical tail corrections, an extrapolation of GEMC simulation data at temperatures in the range from 1.27 to 1.305 yields T c = 1.3128 ± 0.0016, ρ c = 0.316 ± 0.004, and p c = 0.1274 ± 0.0013 in excellent agreement with the thermodynamic limit determined by Potoff and Panagiotopoulos [J. Chem. Phys. 109, 10914 (1998)] using grand canonical Monte Carlo simulations and finite-size scaling. Critical properties estimated using GEMC simulations with different overall system densities (0.296 ≤ ρ t ≤ 0.336) agree to within the statistical uncertainties. For simulations with tail corrections, data obtained using r cut = 3.5σ yield T c and p c that are higher by 0.2% and 1.4% than simulations with r cut = 5 and 8σ but still with overlapping 95% confidence intervals. In contrast, GEMC simulations with a truncated and shifted potential show that r cut = 8σ is insufficient to obtain accurate results. Additional GEMC simulations for hard-core square-well particles with various
Paleocurrents in the Charlie-Gibbs Fracture Zone during the Late Quaternary
Bashirova, L. D.; Dorokhova, E.; Sivkov, V.; Andersen, N.; Kuleshova, L. A.; Matul, A.
2017-12-01
The sedimentary processes prevailing in the Charlie-Gibbs Fracture Zone (CGFZ) are gravity flows. They rework pelagic sediments and contourites, and hereby mask the paleoceanographic information partly. The aim of this work is to study sediments of the AMK-4515 core taken in eastern part of the CGFZ. The sediment core AMK-4515 (52°03.14" N, 29°00.12" W; 370 cm length, water depth 3590 m) is located in the southern valley of the CGFZ. This natural deep corridor is influenced by both the westward Iceland-Scotland Overflow Water and underlying counterflow from the Newfoundland Basin. An alternation of the calcareous silty clays and hemipelagic clayey muds in the studied section indicates similarity between our core and long cores taking from CGFZ. A sharp facies shift was found at 80 cm depth in the investigated core. Only the upper section (0-80 cm) is valid for paleoreconstruction. Planktonic foraminiferal distribution and sea-surface temperature (SST) derived from these allow for tracing the PF and NAC latitudinal migrations during investigated period. So-called sortable silt mean size (SS) was used as proxy for reconstruction of bottom current intensity. The age model is based on δ18O and AMS 14C dating, as well as ice-rafted debris (IRD) counts and CaCO3 content. Stratigraphic subdivision of this section allows to allocate 2 marine isotope stages (MIS) covering the last 27 ka. We refer sediments below this level (80-370 cm) to upper part of turbidite, which was formed as a result of massive slide in the southern channel of the CGFZ. Sandy particles were deposited first, underlying silts and clays. This short-term event occurred so quickly that pelagic sedimentation played no role and was not reflected in the grain size distributions. There is evidence for the significant role of gravity flows in sedimentation in the southern channel of the CGFZ. According to our data, the massive sediment slide occurred in the CGFZ about 27 ka. The authors are grateful to RSF
Subspace Correction Methods for Total Variation and $\\ell_1$-Minimization
Fornasier, Massimo; Schö nlieb, Carola-Bibiane
2009-01-01
This paper is concerned with the numerical minimization of energy functionals in Hilbert spaces involving convex constraints coinciding with a seminorm for a subspace. The optimization is realized by alternating minimizations of the functional on a
Waste minimization assessment procedure
International Nuclear Information System (INIS)
Kellythorne, L.L.
1993-01-01
Perry Nuclear Power Plant began developing a waste minimization plan early in 1991. In March of 1991 the plan was documented following a similar format to that described in the EPA Waste Minimization Opportunity Assessment Manual. Initial implementation involved obtaining management's commitment to support a waste minimization effort. The primary assessment goal was to identify all hazardous waste streams and to evaluate those streams for minimization opportunities. As implementation of the plan proceeded, non-hazardous waste streams routinely generated in large volumes were also evaluated for minimization opportunities. The next step included collection of process and facility data which would be useful in helping the facility accomplish its assessment goals. This paper describes the resources that were used and which were most valuable in identifying both the hazardous and non-hazardous waste streams that existed on site. For each material identified as a waste stream, additional information regarding the materials use, manufacturer, EPA hazardous waste number and DOT hazard class was also gathered. Once waste streams were evaluated for potential source reduction, recycling, re-use, re-sale, or burning for heat recovery, with disposal as the last viable alternative
Duque, Michel; Andraca, Adriana; Goldstein, Patricia; del Castillo, Luis Felipe
2018-04-01
The Adam-Gibbs equation has been used for more than five decades, and still a question remains unanswered on the temperature dependence of the chemical potential it includes. Nowadays, it is a well-known fact that in fragile glass formers, actually the behavior of the system depends on the temperature region it is being studied. Transport coefficients change due to the appearance of heterogeneity in the liquid as it is supercooled. Using the different forms for the logarithmic shift factor and the form of the configurational entropy, we evaluate this temperature dependence and present a discussion on our results.
Starr, Francis W.; Douglas, Jack F.; Sastry, Srikanth
2013-01-01
We carefully examine common measures of dynamical heterogeneity for a model polymer melt and test how these scales compare with those hypothesized by the Adam and Gibbs (AG) and random first-order transition (RFOT) theories of relaxation in glass-forming liquids. To this end, we first analyze clusters of highly mobile particles, the string-like collective motion of these mobile particles, and clusters of relative low mobility. We show that the time scale of the high-mobility clusters and stri...
International Nuclear Information System (INIS)
Arteaga Perez, Luis E; Casas, Yannay; Peralta, Luis M; Granda, Daikenel; Prieto, Julio O
2011-01-01
The use of biofuels plays an important role to increase the efficiency and energetic safety of the energy processes in the world. The main goal of the present research is to study from the thermodynamics and kinetics the effect of the operational variables on the thermo-conversion processes of biomass derived fuels focused on ethanol reforming. Several models are developed to assess the technological proposals. The minimization of Gibbs free energy is the criterion applied to evaluate the performance of the different alternatives considering the equilibrium constraints. All the models where validated on an experimental data base. The gas composition, HHV and the ratio H2/CO are used as measures for the process efficiency. The operational parameters are studied in a wide range (reactants molar ratio, temperature and oxygen/fuel ratio). (author)
Minimal quantization and confinement
International Nuclear Information System (INIS)
Ilieva, N.P.; Kalinowskij, Yu.L.; Nguyen Suan Han; Pervushin, V.N.
1987-01-01
A ''minimal'' version of the Hamiltonian quantization based on the explicit solution of the Gauss equation and on the gauge-invariance principle is considered. By the example of the one-particle Green function we show that the requirement for gauge invariance leads to relativistic covariance of the theory and to more proper definition of the Faddeev - Popov integral that does not depend on the gauge choice. The ''minimal'' quantization is applied to consider the gauge-ambiguity problem and a new topological mechanism of confinement
DEFF Research Database (Denmark)
Channuie, Phongpichit; Jark Joergensen, Jakob; Sannino, Francesco
2011-01-01
We investigate models in which the inflaton emerges as a composite field of a four dimensional, strongly interacting and nonsupersymmetric gauge theory featuring purely fermionic matter. We show that it is possible to obtain successful inflation via non-minimal coupling to gravity, and that the u......We investigate models in which the inflaton emerges as a composite field of a four dimensional, strongly interacting and nonsupersymmetric gauge theory featuring purely fermionic matter. We show that it is possible to obtain successful inflation via non-minimal coupling to gravity...
Minimalism and Speakers’ Intuitions
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Matías Gariazzo
2011-08-01
Full Text Available Minimalism proposes a semantics that does not account for speakers’ intuitions about the truth conditions of a range of sentences or utterances. Thus, a challenge for this view is to offer an explanation of how its assignment of semantic contents to these sentences is grounded in their use. Such an account was mainly offered by Soames, but also suggested by Cappelen and Lepore. The article criticizes this explanation by presenting four kinds of counterexamples to it, and arrives at the conclusion that minimalism has not successfully answered the above-mentioned challenge.
International Nuclear Information System (INIS)
Hosomichi, Kazuo
2008-01-01
We study FZZT-branes and open string amplitudes in (p, q) minimal string theory. We focus on the simplest boundary changing operators in two-matrix models, and identify the corresponding operators in worldsheet theory through the comparison of amplitudes. Along the way, we find a novel linear relation among FZZT boundary states in minimal string theory. We also show that the boundary ground ring is realized on physical open string operators in a very simple manner, and discuss its use for perturbative computation of higher open string amplitudes.
Variations in the Holocene North Atlantic Bottom Current Strength in the Charlie Gibbs Fracture Zone
Kissel, C.; Van Toer, A.; Cortijo, E.; Turon, J.
2011-12-01
The changes in the strength of the North Atlantic bottom current during the Holocene period is presented via the study of cores located at the western termination of the northern deep channel of the Charlie-Gibbs fracture zone. This natural roughly E-W corridor is bathed by the Iceland-Scotland overflow water (ISOW) when it passes westward out of the Iceland Basin into the western North Atlantic basin. At present, it is also described as the place where southern sourced silicate-rich Lower Deep Water (LDW) derived from the Antarctic Bottom Waters (AABW) are passing westward, mixing with the ISOW. We conducted a deep-water multiproxy analysis on two nearby cores, coupling magnetic properties, anisotropy, sortable silt and benthic foraminifera isotopes. The first core had been taken by the R. V. Charcot in 1977 and the second one is a CASQ core taken during the IMAGES-AMOCINT MD168- cruise in the framework of the 06-EuroMARC-FP-008 Project on board the R.V. Marion Dufresne (French Polar Institute, IPEV) in 2008. The radiocarbon ages indicate an average sedimentation rate of about 50 cm/kyr through middle and late Holocene allowing a data resolution ranging from 40 to 100 years depending on the proxy. In each core, we observe long-term and short-term changes in the strength of the bottom currents. On the long term, a decrease in the amount of magnetic particles (normalized by the carbonate content) is first from 10 kyr to 8.6 kyr and then between 6 and 2 kyrs before reaching a steady state. Following Kissel et al. (2009), this indicates a decrease in the ISOW strength. The mean sortable silt shows exactly the same pattern indicating that not only the intensity of the ISOW but the whole deep water mass bathing the sites has decreased. On the short term, a first very prominent event centered at about 8.4 kyr (cal. ages) is marked by a pronounced minima in magnetic content and the smaller mean sortable silt sizes. This is typical for an abrupt reduction in deep flow
International Nuclear Information System (INIS)
Gaberdiel, Matthias R; Gopakumar, Rajesh
2013-01-01
We review the duality relating 2D W N minimal model conformal field theories, in a large-N ’t Hooft like limit, to higher spin gravitational theories on AdS 3 . This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Higher spin theories and holography’. (review)
Minimal constrained supergravity
Energy Technology Data Exchange (ETDEWEB)
Cribiori, N. [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Dall' Agata, G., E-mail: dallagat@pd.infn.it [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Farakos, F. [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Porrati, M. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)
2017-01-10
We describe minimal supergravity models where supersymmetry is non-linearly realized via constrained superfields. We show that the resulting actions differ from the so called “de Sitter” supergravities because we consider constraints eliminating directly the auxiliary fields of the gravity multiplet.
International Nuclear Information System (INIS)
Freeman, H.
1990-01-01
This book presents an overview of waste minimization. Covers applications of technology to waste reduction, techniques for implementing programs, incorporation of programs into R and D, strategies for private industry and the public sector, and case studies of programs already in effect
Minimally invasive distal pancreatectomy
Røsok, Bård I.; de Rooij, Thijs; van Hilst, Jony; Diener, Markus K.; Allen, Peter J.; Vollmer, Charles M.; Kooby, David A.; Shrikhande, Shailesh V.; Asbun, Horacio J.; Barkun, Jeffrey; Besselink, Marc G.; Boggi, Ugo; Conlon, Kevin; Han, Ho Seong; Hansen, Paul; Kendrick, Michael L.; Kooby, David; Montagnini, Andre L.; Palanivelu, Chinnasamy; Wakabayashi, Go; Zeh, Herbert J.
2017-01-01
The first International conference on Minimally Invasive Pancreas Resection was arranged in conjunction with the annual meeting of the International Hepato-Pancreato-Biliary Association (IHPBA), in Sao Paulo, Brazil on April 19th 2016. The presented evidence and outcomes resulting from the session
DEFF Research Database (Denmark)
David, Alexandre; Håkansson, John; G. Larsen, Kim
In this paper we present an algorithm to compute DBM substractions with a guaranteed minimal number of splits and disjoint DBMs to avoid any redundance. The substraction is one of the few operations that result in a non-convex zone, and thus, requires splitting. It is of prime importance to reduce...
Minimal constrained supergravity
Directory of Open Access Journals (Sweden)
N. Cribiori
2017-01-01
Full Text Available We describe minimal supergravity models where supersymmetry is non-linearly realized via constrained superfields. We show that the resulting actions differ from the so called “de Sitter” supergravities because we consider constraints eliminating directly the auxiliary fields of the gravity multiplet.
Minimal constrained supergravity
International Nuclear Information System (INIS)
Cribiori, N.; Dall'Agata, G.; Farakos, F.; Porrati, M.
2017-01-01
We describe minimal supergravity models where supersymmetry is non-linearly realized via constrained superfields. We show that the resulting actions differ from the so called “de Sitter” supergravities because we consider constraints eliminating directly the auxiliary fields of the gravity multiplet.
Gravitino problem in minimal supergravity inflation
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Fuminori Hasegawa
2017-04-01
Full Text Available We study non-thermal gravitino production in the minimal supergravity inflation. In this minimal model utilizing orthogonal nilpotent superfields, the particle spectrum includes only graviton, gravitino, inflaton, and goldstino. We find that a substantial fraction of the cosmic energy density can be transferred to the longitudinal gravitino due to non-trivial change of its sound speed. This implies either a breakdown of the effective theory after inflation or a serious gravitino problem.
Gravitino problem in minimal supergravity inflation
Energy Technology Data Exchange (ETDEWEB)
Hasegawa, Fuminori [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Mukaida, Kyohei [Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Nakayama, Kazunori [Department of Physics, Faculty of Science, The University of Tokyo, Bunkyo-ku, Tokyo 133-0033 (Japan); Terada, Takahiro, E-mail: terada@kias.re.kr [School of Physics, Korea Institute for Advanced Study (KIAS), Seoul 02455 (Korea, Republic of); Yamada, Yusuke [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94305 (United States)
2017-04-10
We study non-thermal gravitino production in the minimal supergravity inflation. In this minimal model utilizing orthogonal nilpotent superfields, the particle spectrum includes only graviton, gravitino, inflaton, and goldstino. We find that a substantial fraction of the cosmic energy density can be transferred to the longitudinal gravitino due to non-trivial change of its sound speed. This implies either a breakdown of the effective theory after inflation or a serious gravitino problem.
Black, Clanton C
2008-01-01
The very personal touch of Professor Martin Gibbs as a worldwide advocate for photosynthesis and plant physiology was lost with his death in July 2006. Widely known for his engaging humorous personality and his humanitarian lifestyle, Martin Gibbs excelled as a strong international science diplomat; like a personal science family patriarch encouraging science and plant scientists around the world. Immediately after World War II he was a pioneer at the Brookhaven National Laboratory in the use of (14)C to elucidate carbon flow in metabolism and particularly carbon pathways in photosynthesis. His leadership on carbon metabolism and photosynthesis extended for four decades of working in collaboration with a host of students and colleagues. In 1962, he was selected as the Editor-in-Chief of Plant Physiology. That appointment initiated 3 decades of strong directional influences by Gibbs on plant research and photosynthesis. Plant Physiology became and remains a premier source of new knowledge about the vital and primary roles of plants in earth's environmental history and the energetics of our green-blue planet. His leadership and charismatic humanitarian character became the quintessence of excellence worldwide. Martin Gibbs was in every sense the personification of a model mentor not only for scientists but also shown in devotion to family. Here we pay tribute and honor to an exemplary humanistic mentor, Martin Gibbs.
Energy Technology Data Exchange (ETDEWEB)
BLOCH, Claude; DE DOMINICIS, Cyrano [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' etudes Nucleaires de Saclay, Gif-sur-Yvette (France)
1959-07-01
Starting from an expansion derived in a previous work, we study the contribution to the Gibbs potential of the two-body dynamical correlations, taking into account the statistical correlations. Such a contribution is of interest for low-density systems at low temperature. In the zero density limit, it reduces to the Beth-Uhlenbeck expression for the second virial coefficient. For a system of fermions in the zero temperature limit, it yields the contribution of the Brueckner reaction matrix to the ground state energy, plus, under certain conditions, additional terms of the form exp ( β / Δ /), where the Δ are the binding energies of 'bound states' of the type first discussed by L. Cooper. Finally, we study the wave function of two particles immersed in a medium (defined by its temperature and chemical potential). It satisfies an equation generalizing the Bethe-Goldstone equation for an arbitrary temperature. Reprint of a paper published in Nuclear Physics, 10, p. 509-526, 1959.
Directory of Open Access Journals (Sweden)
João Carlos Magi
2017-04-01
Full Text Available Minimally invasive procedures aim to resolve the disease with minimal trauma to the body, resulting in a rapid return to activities and in reductions of infection, complications, costs and pain. Minimally incised laparotomy, sometimes referred to as minilaparotomy, is an example of such minimally invasive procedures. The aim of this study is to demonstrate the feasibility and utility of laparotomy with minimal incision based on the literature and exemplifying with a case. The case in question describes reconstruction of the intestinal transit with the use of this incision. Male, young, HIV-positive patient in a late postoperative of ileotiflectomy, terminal ileostomy and closing of the ascending colon by an acute perforating abdomen, due to ileocolonic tuberculosis. The barium enema showed a proximal stump of the right colon near the ileostomy. The access to the cavity was made through the orifice resulting from the release of the stoma, with a lateral-lateral ileo-colonic anastomosis with a 25 mm circular stapler and manual closure of the ileal stump. These surgeries require their own tactics, such as rigor in the lysis of adhesions, tissue traction, and hemostasis, in addition to requiring surgeon dexterity – but without the need for investments in technology; moreover, the learning curve is reported as being lower than that for videolaparoscopy. Laparotomy with minimal incision should be considered as a valid and viable option in the treatment of surgical conditions. Resumo: Procedimentos minimamente invasivos visam resolver a doença com o mínimo de trauma ao organismo, resultando em retorno rápido às atividades, reduções nas infecções, complicações, custos e na dor. A laparotomia com incisão mínima, algumas vezes referida como minilaparotomia, é um exemplo desses procedimentos minimamente invasivos. O objetivo deste trabalho é demonstrar a viabilidade e utilidade das laparotomias com incisão mínima com base na literatura e
10 CFR 20.1406 - Minimization of contamination.
2010-01-01
... 10 Energy 1 2010-01-01 2010-01-01 false Minimization of contamination. 20.1406 Section 20.1406... License Termination § 20.1406 Minimization of contamination. (a) Applicants for licenses, other than early... procedures for operation will minimize, to the extent practicable, contamination of the facility and the...
Borge, Javier
2015-01-01
G, G°, [delta][subscript r]G, [delta][subscript r]G°, [delta]G, and [delta]G° are essential quantities to master the chemical equilibrium. Although the number of publications devoted to explaining these items is extremely high, it seems that they do not produce the desired effect because some articles and textbooks are still being written with…
The effect of 2,2,2-trifluoroethanol on water studied by using third derivatives of Gibbs energy, G
DEFF Research Database (Denmark)
Ohgi, Hiroyo; Imamura, Hiroshi; Yonenaga, Kazuki
2016-01-01
We determined the excess partial molar enthalpy and the excess partial molar volume, HTFEE, VTFEE, of 2,2,2-trifluoroethanol (TFE) in TFE-H2O at 25.0 °C. We then evaluate the TFE-TFE interactions in terms of enthalpy and volume, HTFE-TFEE and VTFE-TFEE, graphically without resorting to any model...
Legal incentives for minimizing waste
International Nuclear Information System (INIS)
Clearwater, S.W.; Scanlon, J.M.
1991-01-01
Waste minimization, or pollution prevention, has become an integral component of federal and state environmental regulation. Minimizing waste offers many economic and public relations benefits. In addition, waste minimization efforts can also dramatically reduce potential criminal requirements. This paper addresses the legal incentives for minimizing waste under current and proposed environmental laws and regulations
Directory of Open Access Journals (Sweden)
La Iglesia, A.
1989-12-01
Full Text Available The effect of grinding on crystallinity, particle size and solubility of two samples of kaolinite was studied. The standard Gibbs free energies of formation of different ground samples were calculated from solubility measurements, and show a direct relationship between Gibbs free energy and particle size-crystallinity variation. Values of -3752.2 and -3776.4 KJ/mol. were determinated for ÎGÂºl (am and ÎGÂºl (crys of kaolinite, respectively. A new thermodinamic equation that relates ÎGÂºl to particle size is proposed. This equation can probably be extended to clay mineals.Se estudia el efecto de la molienda prolongada sobre la cristalinidad, tamaño de partícula y solubilidad de dos muestras de caolinita. Se ha calculado la energía libre estandar de formación del mineral a partir de medidas de solubilidad, encontrando una relación directa entre ÎGÂºl, y las variaciones de tamaño de partícula y cristalinidad de las muestras. Por extrapolación, se han obtenido los valores de -3752,0 y -3776,4 KJ/mol. para ÎGÂºl caolinita amorfa y cristalina. Se propone una ecuación termodinámica que relaciona ÎGÂºl y el tamaño de partícula de la caolinita; esta ecuación puede aplicarse también a otros minerales de la arcilla.
International Nuclear Information System (INIS)
Fischler, Mark S.; Sachs, D.
2004-01-01
A new object-oriented Minimization package is available for distribution in the same manner as CLHEP. This package, designed for use in HEP applications, has all the capabilities of Minuit, but is a re-write from scratch, adhering to modern C++ design principles. A primary goal of this package is extensibility in several directions, so that its capabilities can be kept fresh with as little maintenance effort as possible. This package is distinguished by the priority that was assigned to C++ design issues, and the focus on producing an extensible system that will resist becoming obsolete
International Nuclear Information System (INIS)
Ritson, D.; Chou, W.
1997-10-01
The Pacman bunches will experience two deleterious effects: tune shift and orbit displacement. It is known that the tune shift can be compensated by arranging crossing planes 900 relative to each other at successive interaction points (lPs). This paper gives an analytical estimate of the Pacman orbit displacement for a single as well as for two crossings. For the latter, it can be minimized by using equal phase advances from one IP to another. In the LHC, this displacement is in any event small and can be neglected
Minimally Invasive Parathyroidectomy
Directory of Open Access Journals (Sweden)
Lee F. Starker
2011-01-01
Full Text Available Minimally invasive parathyroidectomy (MIP is an operative approach for the treatment of primary hyperparathyroidism (pHPT. Currently, routine use of improved preoperative localization studies, cervical block anesthesia in the conscious patient, and intraoperative parathyroid hormone analyses aid in guiding surgical therapy. MIP requires less surgical dissection causing decreased trauma to tissues, can be performed safely in the ambulatory setting, and is at least as effective as standard cervical exploration. This paper reviews advances in preoperative localization, anesthetic techniques, and intraoperative management of patients undergoing MIP for the treatment of pHPT.
Waste minimization activity report for 1991
International Nuclear Information System (INIS)
Shoemaker, J.D.
1992-01-01
This is a waste reduction report for the Lawrence Livermore National Laboratory (LLNL) for 1991. The report covers the Main Site at Livermore and Site 300. Each research program at LLNL is described by its operation, administrative procedures, and waste minimization. Examples of the programs at LLNL are biomedical and environmental research, chemistry and materials science, and energy program and earth sciences. (MB)
Energy Technology Data Exchange (ETDEWEB)
Helmboldt, Alexander; Humbert, Pascal; Lindner, Manfred; Smirnov, Juri [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)
2016-07-01
The gauge hierarchy problem is one of the crucial drawbacks of the standard model of particle physics (SM) and thus has triggered model building over the last decades. Its most famous solution is the introduction of low-scale supersymmetry. However, without any significant signs of supersymmetric particles at the LHC to date, it makes sense to devise alternative mechanisms to remedy the hierarchy problem. One such mechanism is based on classically scale-invariant extensions of the SM, in which both the electroweak symmetry and the (anomalous) scale symmetry are broken radiatively via the Coleman-Weinberg mechanism. Apart from giving an introduction to classically scale-invariant models, the talk presents our results on obtaining a theoretically consistent minimal extension of the SM, which reproduces the correct low-scale phenomenology.
Directory of Open Access Journals (Sweden)
Iris Iddaly Mendez Gurrola
2011-03-01
Full Text Available The proper detection of patient level of dementia is important to offer the suitable treatment. The diagnosis is based on certain criteria, reflected in the clinical examinations. From these examinations emerge the limitations and the degree in which each patient is in. In order to reduce the total of limitations to be evaluated, we used the rough set theory, this theory has been applied in areas of the artificial intelligence such as decision analysis, expert systems, knowledge discovery, classification with multiple attributes. In our case this theory is applied to find the minimal limitations set or reduct that generate the same classification that considering all the limitations, to fulfill this purpose we development an algorithm GRASP (Greedy Randomized Adaptive Search Procedure.
International Nuclear Information System (INIS)
Chala, Mikael; Grojean, Christophe; Humboldt-Univ. Berlin; Lima, Leonardo de; Univ. Estadual Paulista, Sao Paulo
2017-03-01
Higgs boson compositeness is a phenomenologically viable scenario addressing the hierarchy problem. In minimal models, the Higgs boson is the only degree of freedom of the strong sector below the strong interaction scale. We present here the simplest extension of such a framework with an additional composite spin-zero singlet. To this end, we adopt an effective field theory approach and develop a set of rules to estimate the size of the various operator coefficients, relating them to the parameters of the strong sector and its structural features. As a result, we obtain the patterns of new interactions affecting both the new singlet and the Higgs boson's physics. We identify the characteristics of the singlet field which cause its effects on Higgs physics to dominate over the ones inherited from the composite nature of the Higgs boson. Our effective field theory construction is supported by comparisons with explicit UV models.
Energy Technology Data Exchange (ETDEWEB)
Chala, Mikael [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Valencia Univ. (Spain). Dept. de Fisica Teorica y IFIC; Durieux, Gauthier; Matsedonskyi, Oleksii [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Grojean, Christophe [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Humboldt-Univ. Berlin (Germany). Inst. fuer Physik; Lima, Leonardo de [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Univ. Estadual Paulista, Sao Paulo (Brazil). Inst. de Fisica Teorica
2017-03-15
Higgs boson compositeness is a phenomenologically viable scenario addressing the hierarchy problem. In minimal models, the Higgs boson is the only degree of freedom of the strong sector below the strong interaction scale. We present here the simplest extension of such a framework with an additional composite spin-zero singlet. To this end, we adopt an effective field theory approach and develop a set of rules to estimate the size of the various operator coefficients, relating them to the parameters of the strong sector and its structural features. As a result, we obtain the patterns of new interactions affecting both the new singlet and the Higgs boson's physics. We identify the characteristics of the singlet field which cause its effects on Higgs physics to dominate over the ones inherited from the composite nature of the Higgs boson. Our effective field theory construction is supported by comparisons with explicit UV models.
Evard, Margarita E.; Volkov, Aleksandr E.; Belyaev, Fedor S.; Ignatova, Anna D.
2018-05-01
The choice of Gibbs' potential for microstructural modeling of FCC ↔ HCP martensitic transformation in FeMn-based shape memory alloys is discussed. Threefold symmetry of the HCP phase is taken into account on specifying internal variables characterizing volume fractions of martensite variants. Constraints imposed on model constants by thermodynamic equilibrium conditions are formulated.
Hadamard and minimal renormalizations
International Nuclear Information System (INIS)
Castagnino, M.A.; Gunzig, E.; Nardone, P.; Paz, J.P.
1986-01-01
A common language is introduced to study two, well-known, different methods for the renormalization of the energy-momentum tensor of a scalar neutral quantum field in curved space-time. Different features of the two renormalizations are established and compared
Directory of Open Access Journals (Sweden)
Leandro Barbosa
2008-07-01
Full Text Available Um total de 38.865 registros de animais da raça Large White foi usado para estimar componentes de co-variância e parâmetros genéticos das características idade ao atingir 100 kg de peso vivo (IDA e espessura de toucinho ajustada para 100 kg de peso vivo (ET, em análises bicaracterísticas. Para obtenção dos componentes de co-variância, foi utilizado o Amostrador de Gibbs por meio do programa MTGSAM. O modelo misto utilizado continha efeito fixo de grupo contemporâneo e os seguintes efeitos aleatórios: efeito genético aditivo direto, efeito genético aditivo materno, efeito comum de leitegada e efeito residual. As médias das estimativas de herdabilidade aditivas diretas foram 0,33 e 0,44 para IDA e ET, respectivamente. As médias das estimativas do efeito comum de leitegada foram 0,09 e 0,02 para IDA e ET, respectivamente. A estimativa de correlação genética aditiva entre as características foi próxima de zero (-0,015. As herdabilidades obtidas para as características de desempenho avaliadas indicam que ganhos genéticos satisfatórios podem ser obtidos no melhoramento de suínos da raça Large White para essas características e que a seleção simultânea para ambas as características pode ser realizada, uma vez que é baixa a correlação genética aditiva direta.Data consisting of 38,865 records of Large White pigs were used to estimate genetic parameters for days to 100 kg (DAYS and backfat thickness adjusted to 100 kg (BF. Covariance components were estimated by a bivariate mixed model including the fixed effect of contemporary group and the direct and maternal additive genetic, common litter and residual random effects using the Gibbs Sampling algorithm of the MTGSAM program. Estimates of direct and common litter effects for DAYS and BF were 0.33 and 0.44 and 0.09 and 0.02, respectively. Additive genetic correlation between DAYS and BF was close to zero (-0.015. The heritability estimates indicate that genetic gains may
A Short Essay on the Uses of Free Energy
Koutandos, Spyridon
2013-01-01
In this article we examine cases of more classical and less classical nature compared to results found by quantum mechanics and attribute a form of Free Energy discontinuity for each case within a boundary layer. The concept of a boundary layer is broadened as to include areas of first or second variations of the Gibbs free energy. It is…
International Nuclear Information System (INIS)
Meister, F.; Ott, F.
2002-01-01
This chapter gives an overview of the current energy economy in Austria. The Austrian political aims of sustainable development and climate protection imply a reorientation of the Austrian energy policy as a whole. Energy consumption trends (1993-1998), final energy consumption by energy carrier (indexed data 1993-1999), comparative analysis of useful energy demand (1993 and 1999) and final energy consumption of renewable energy sources by sector (1996-1999) in Austria are given. The necessary measures to be taken in order to reduce the energy demand and increased the use of renewable energy are briefly mentioned. Figs. 5. (nevyjel)
Minimal Marking: A Success Story
McNeilly, Anne
2014-01-01
The minimal-marking project conducted in Ryerson's School of Journalism throughout 2012 and early 2013 resulted in significantly higher grammar scores in two first-year classes of minimally marked university students when compared to two traditionally marked classes. The "minimal-marking" concept (Haswell, 1983), which requires…
Sharkey, Amanda J. C.
2007-09-01
Swarm Robotics (SR) is closely related to Swarm Intelligence, and both were initially inspired by studies of social insects. Their guiding principles are based on their biological inspiration and take the form of an emphasis on decentralized local control and communication. Earlier studies went a step further in emphasizing the use of simple reactive robots that only communicate indirectly through the environment. More recently SR studies have moved beyond these constraints to explore the use of non-reactive robots that communicate directly, and that can learn and represent their environment. There is no clear agreement in the literature about how far such extensions of the original principles could go. Should there be any limitations on the individual abilities of the robots used in SR studies? Should knowledge of the capabilities of social insects lead to constraints on the capabilities of individual robots in SR studies? There is a lack of explicit discussion of such questions, and researchers have adopted a variety of constraints for a variety of reasons. A simple taxonomy of swarm robotics is presented here with the aim of addressing and clarifying these questions. The taxonomy distinguishes subareas of SR based on the emphases and justifications for minimalism and individual simplicity.
Directory of Open Access Journals (Sweden)
Oda Kin-ya
2013-05-01
Full Text Available Both the ATLAS and CMS experiments at the LHC have reported the observation of the particle of mass around 125 GeV which is consistent to the Standard Model (SM Higgs boson, but with an excess of events beyond the SM expectation in the diphoton decay channel at each of them. There still remains room for a logical possibility that we are not seeing the SM Higgs but something else. Here we introduce the minimal dilaton model in which the LHC signals are explained by an extra singlet scalar of the mass around 125 GeV that slightly mixes with the SM Higgs heavier than 600 GeV. When this scalar has a vacuum expectation value well beyond the electroweak scale, it can be identified as a linearly realized version of a dilaton field. Though the current experimental constraints from the Higgs search disfavors such a region, the singlet scalar model itself still provides a viable alternative to the SM Higgs in interpreting its search results.
Energy Technology Data Exchange (ETDEWEB)
Barbieri, Riccardo [Institute of Theoretical Studies, ETH Zurich,CH-8092 Zurich (Switzerland); Scuola Normale Superiore,Piazza dei Cavalieri 7, 56126 Pisa (Italy); Hall, Lawrence J.; Harigaya, Keisuke [Department of Physics, University of California,Berkeley, California 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,Berkeley, California 94720 (United States)
2016-11-29
In a Mirror Twin World with a maximally symmetric Higgs sector the little hierarchy of the Standard Model can be significantly mitigated, perhaps displacing the cutoff scale above the LHC reach. We show that consistency with observations requires that the Z{sub 2} parity exchanging the Standard Model with its mirror be broken in the Yukawa couplings. A minimal such effective field theory, with this sole Z{sub 2} breaking, can generate the Z{sub 2} breaking in the Higgs sector necessary for the Twin Higgs mechanism. The theory has constrained and correlated signals in Higgs decays, direct Dark Matter Detection and Dark Radiation, all within reach of foreseen experiments, over a region of parameter space where the fine-tuning for the electroweak scale is 10-50%. For dark matter, both mirror neutrons and a variety of self-interacting mirror atoms are considered. Neutrino mass signals and the effects of a possible additional Z{sub 2} breaking from the vacuum expectation values of B−L breaking fields are also discussed.
International Nuclear Information System (INIS)
Meister, F.
2001-01-01
This chapter of the environmental control report deals with the environmental impact of energy production, energy conversion, atomic energy and renewable energy. The development of the energy consumption in Austria for the years 1993 to 1999 is given for the different energy types. The development of the use of renewable energy sources in Austria is given, different domestic heat-systems are compared, life cycles and environmental balance are outlined. (a.n.)
Waste minimization in analytical methods
International Nuclear Information System (INIS)
Green, D.W.; Smith, L.L.; Crain, J.S.; Boparai, A.S.; Kiely, J.T.; Yaeger, J.S. Schilling, J.B.
1995-01-01
The US Department of Energy (DOE) will require a large number of waste characterizations over a multi-year period to accomplish the Department's goals in environmental restoration and waste management. Estimates vary, but two million analyses annually are expected. The waste generated by the analytical procedures used for characterizations is a significant source of new DOE waste. Success in reducing the volume of secondary waste and the costs of handling this waste would significantly decrease the overall cost of this DOE program. Selection of appropriate analytical methods depends on the intended use of the resultant data. It is not always necessary to use a high-powered analytical method, typically at higher cost, to obtain data needed to make decisions about waste management. Indeed, for samples taken from some heterogeneous systems, the meaning of high accuracy becomes clouded if the data generated are intended to measure a property of this system. Among the factors to be considered in selecting the analytical method are the lower limit of detection, accuracy, turnaround time, cost, reproducibility (precision), interferences, and simplicity. Occasionally, there must be tradeoffs among these factors to achieve the multiple goals of a characterization program. The purpose of the work described here is to add waste minimization to the list of characteristics to be considered. In this paper the authors present results of modifying analytical methods for waste characterization to reduce both the cost of analysis and volume of secondary wastes. Although tradeoffs may be required to minimize waste while still generating data of acceptable quality for the decision-making process, they have data demonstrating that wastes can be reduced in some cases without sacrificing accuracy or precision
Evolved Minimal Frustration in Multifunctional Biomolecules.
Röder, Konstantin; Wales, David J
2018-05-25
Protein folding is often viewed in terms of a funnelled potential or free energy landscape. A variety of experiments now indicate the existence of multifunnel landscapes, associated with multifunctional biomolecules. Here, we present evidence that these systems have evolved to exhibit the minimal number of funnels required to fulfil their cellular functions, suggesting an extension to the principle of minimum frustration. We find that minimal disruptive mutations result in additional funnels, and the associated structural ensembles become more diverse. The same trends are observed in an atomic cluster. These observations suggest guidelines for rational design of engineered multifunctional biomolecules.
Advanced pyrochemical technologies for minimizing nuclear waste
International Nuclear Information System (INIS)
Bronson, M.C.; Dodson, K.E.; Riley, D.C.
1994-01-01
The Department of Energy (DOE) is seeking to reduce the size of the current nuclear weapons complex and consequently minimize operating costs. To meet this DOE objective, the national laboratories have been asked to develop advanced technologies that take uranium and plutonium, from retired weapons and prepare it for new weapons, long-term storage, and/or final disposition. Current pyrochemical processes generate residue salts and ceramic wastes that require aqueous processing to remove and recover the actinides. However, the aqueous treatment of these residues generates an estimated 100 liters of acidic transuranic (TRU) waste per kilogram of plutonium in the residue. Lawrence Livermore National Laboratory (LLNL) is developing pyrochemical techniques to eliminate, minimize, or more efficiently treat these residue streams. This paper will present technologies being developed at LLNL on advanced materials for actinide containment, reactors that minimize residues, and pyrochemical processes that remove actinides from waste salts
Waste minimization at Chalk River Laboratories
International Nuclear Information System (INIS)
Kranz, P.; Wong, P.C.F.
2011-01-01
Waste minimization supports Atomic Energy of Canada Limited (AECL) Environment Policy with regard to pollution prevention and has positive impacts on the environment, human health and safety, and economy. In accordance with the principle of pollution prevention, the quantities and degree of hazard of wastes requiring storage or disposition at facilities within or external to AECL sites shall be minimized, following the principles of Prevent, Reduce, Reuse, and Recycle, to the extent practical. Waste minimization is an important element in the Waste Management Program. The Waste Management Program has implemented various initiatives for waste minimization since 2007. The key initiatives have focused on waste reduction, segregation and recycling, and included: 1) developed waste minimization requirements and recycling procedure to establish the framework for applying the Waste Minimization Hierarchy; 2) performed waste minimization assessments for the facilities, which generate significant amounts of waste, to identify the opportunities for waste reduction and assist the waste generators to develop waste reduction targets and action plans to achieve the targets; 3) implemented the colour-coded, standardized waste and recycling containers to enhance waste segregation; 4) established partnership with external agents for recycling; 5) extended the likely clean waste and recyclables collection to selected active areas; 6) provided on-going communications to promote waste reduction and increase awareness for recycling; and 7) continually monitored performance, with respect to waste minimization, to identify opportunities for improvement and to communicate these improvements. After implementation of waste minimization initiatives at CRL, the solid waste volume generated from routine operations at CRL has significantly decreased, while the amount of recyclables diverted from the onsite landfill has significantly increased since 2007. The overall refuse volume generated at
Waste minimization at Chalk River Laboratories
Energy Technology Data Exchange (ETDEWEB)
Kranz, P.; Wong, P.C.F. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)
2011-07-01
Waste minimization supports Atomic Energy of Canada Limited (AECL) Environment Policy with regard to pollution prevention and has positive impacts on the environment, human health and safety, and economy. In accordance with the principle of pollution prevention, the quantities and degree of hazard of wastes requiring storage or disposition at facilities within or external to AECL sites shall be minimized, following the principles of Prevent, Reduce, Reuse, and Recycle, to the extent practical. Waste minimization is an important element in the Waste Management Program. The Waste Management Program has implemented various initiatives for waste minimization since 2007. The key initiatives have focused on waste reduction, segregation and recycling, and included: 1) developed waste minimization requirements and recycling procedure to establish the framework for applying the Waste Minimization Hierarchy; 2) performed waste minimization assessments for the facilities, which generate significant amounts of waste, to identify the opportunities for waste reduction and assist the waste generators to develop waste reduction targets and action plans to achieve the targets; 3) implemented the colour-coded, standardized waste and recycling containers to enhance waste segregation; 4) established partnership with external agents for recycling; 5) extended the likely clean waste and recyclables collection to selected active areas; 6) provided on-going communications to promote waste reduction and increase awareness for recycling; and 7) continually monitored performance, with respect to waste minimization, to identify opportunities for improvement and to communicate these improvements. After implementation of waste minimization initiatives at CRL, the solid waste volume generated from routine operations at CRL has significantly decreased, while the amount of recyclables diverted from the onsite landfill has significantly increased since 2007. The overall refuse volume generated at
Waste Minimization and Pollution Prevention Awareness Plan
International Nuclear Information System (INIS)
1992-01-01
The purpose of this plan is to document the Lawrence Livermore National Laboratory (LLNL) Waste Minimization and Pollution Prevention Awareness Program. The plan specifies those activities and methods that are or will be employed to reduce the quantity and toxicity of wastes generated at the site. It is intended to satisfy Department of Energy (DOE) and other legal requirements that are discussed in Section C, below. The Pollution Prevention Awareness Program is included with the Waste Minimization Program as suggested by DOE Order 5400.1. The intent of this plan is to respond to and comply with the Department's policy and guidelines concerning the need for pollution prevention. The Plan is composed of a LLNL Waste Minimization and Pollution Prevention Awareness Program Plan and, as attachments, Directorate-, Program- and Department-specific waste minimization plans. This format reflects the fact that waste minimization is considered a line management responsibility and is to be addressed by each of the Directorates, Programs and Departments. Several Directorates have been reorganized, necessitating changes in the Directorate plans that were published in 1991
Image denoising by a direct variational minimization
Directory of Open Access Journals (Sweden)
Pilipović Stevan
2011-01-01
Full Text Available Abstract In this article we introduce a novel method for the image de-noising which combines a mathematically well-posdenes of the variational modeling with the efficiency of a patch-based approach in the field of image processing. It based on a direct minimization of an energy functional containing a minimal surface regularizer that uses fractional gradient. The minimization is obtained on every predefined patch of the image, independently. By doing so, we avoid the use of an artificial time PDE model with its inherent problems of finding optimal stopping time, as well as the optimal time step. Moreover, we control the level of image smoothing on each patch (and thus on the whole image by adapting the Lagrange multiplier using the information on the level of discontinuities on a particular patch, which we obtain by pre-processing. In order to reduce the average number of vectors in the approximation generator and still to obtain the minimal degradation, we combine a Ritz variational method for the actual minimization on a patch, and a complementary fractional variational principle. Thus, the proposed method becomes computationally feasible and applicable for practical purposes. We confirm our claims with experimental results, by comparing the proposed method with a couple of PDE-based methods, where we get significantly better denoising results specially on the oscillatory regions.
International Nuclear Information System (INIS)
Bobin, J.L.
1996-01-01
Object of sciences and technologies, energy plays a major part in economics and relations between nations. Jean-Louis Bobin, physicist, analyses the relations between man and energy and wonders about fears that delivers nowadays technologies bound to nuclear energy and about the fear of a possible shortage of energy resources. (N.C.). 17 refs., 14 figs., 2 tabs
Foland, Andrew Dean
2007-01-01
Energy is the central concept of physics. Unable to be created or destroyed but transformable from one form to another, energy ultimately determines what is and isn''t possible in our universe. This book gives readers an appreciation for the limits of energy and the quantities of energy in the world around them. This fascinating book explores the major forms of energy: kinetic, potential, electrical, chemical, thermal, and nuclear.
Power Minimization techniques for Networked Data Centers
International Nuclear Information System (INIS)
Low, Steven; Tang, Kevin
2011-01-01
Our objective is to develop a mathematical model to optimize energy consumption at multiple levels in networked data centers, and develop abstract algorithms to optimize not only individual servers, but also coordinate the energy consumption of clusters of servers within a data center and across geographically distributed data centers to minimize the overall energy cost and consumption of brown energy of an enterprise. In this project, we have formulated a variety of optimization models, some stochastic others deterministic, and have obtained a variety of qualitative results on the structural properties, robustness, and scalability of the optimal policies. We have also systematically derived from these models decentralized algorithms to optimize energy efficiency, analyzed their optimality and stability properties. Finally, we have conducted preliminary numerical simulations to illustrate the behavior of these algorithms. We draw the following conclusion. First, there is a substantial opportunity to minimize both the amount and the cost of electricity consumption in a network of datacenters, by exploiting the fact that traffic load, electricity cost, and availability of renewable generation fluctuate over time and across geographical locations. Judiciously matching these stochastic processes can optimize the tradeoff between brown energy consumption, electricity cost, and response time. Second, given the stochastic nature of these three processes, real-time dynamic feedback should form the core of any optimization strategy. The key is to develop decentralized algorithms that can be implemented at different parts of the network as simple, local algorithms that coordinate through asynchronous message passing.
Global Analysis of Minimal Surfaces
Dierkes, Ulrich; Tromba, Anthony J
2010-01-01
Many properties of minimal surfaces are of a global nature, and this is already true for the results treated in the first two volumes of the treatise. Part I of the present book can be viewed as an extension of these results. For instance, the first two chapters deal with existence, regularity and uniqueness theorems for minimal surfaces with partially free boundaries. Here one of the main features is the possibility of 'edge-crawling' along free parts of the boundary. The third chapter deals with a priori estimates for minimal surfaces in higher dimensions and for minimizers of singular integ
Minimal Surfaces for Hitchin Representations
DEFF Research Database (Denmark)
Li, Qiongling; Dai, Song
2018-01-01
. In this paper, we investigate the properties of immersed minimal surfaces inside symmetric space associated to a subloci of Hitchin component: $q_n$ and $q_{n-1}$ case. First, we show that the pullback metric of the minimal surface dominates a constant multiple of the hyperbolic metric in the same conformal...... class and has a strong rigidity property. Secondly, we show that the immersed minimal surface is never tangential to any flat inside the symmetric space. As a direct corollary, the pullback metric of the minimal surface is always strictly negatively curved. In the end, we find a fully decoupled system...
Commercial radioactive waste minimization program development guidance
International Nuclear Information System (INIS)
Fischer, D.K.
1991-01-01
This document is one of two prepared by the EG ampersand G Idaho, Inc., Waste Management Technical Support Program Group, National Low-Level Waste Management Program Unit. One of several Department of Energy responsibilities stated in the Amendments Act of 1985 is to provide technical assistance to compact regions Host States, and nonmember States (to the extent provided in appropriations acts) in establishing waste minimization program plans. Technical assistance includes, among other things, the development of technical guidelines for volume reduction options. Pursuant to this defined responsibility, the Department of Energy (through EG ampersand G Idaho, Inc.) has prepared this report, which includes guidance on defining a program, State/compact commission participation, and waste minimization program plans
Mean-field approximation minimizes relative entropy
International Nuclear Information System (INIS)
Bilbro, G.L.; Snyder, W.E.; Mann, R.C.
1991-01-01
The authors derive the mean-field approximation from the information-theoretic principle of minimum relative entropy instead of by minimizing Peierls's inequality for the Weiss free energy of statistical physics theory. They show that information theory leads to the statistical mechanics procedure. As an example, they consider a problem in binary image restoration. They find that mean-field annealing compares favorably with the stochastic approach
Cyclone Simulation via Action Minimization
Plotkin, D. A.; Weare, J.; Abbot, D. S.
2016-12-01
A postulated impact of climate change is an increase in intensity of tropical cyclones (TCs). This hypothesized effect results from the fact that TCs are powered subsaturated boundary layer air picking up water vapor from the surface ocean as it flows inwards towards the eye. This water vapor serves as the energy input for TCs, which can be idealized as heat engines. The inflowing air has a nearly identical temperature as the surface ocean; therefore, warming of the surface leads to a warmer atmospheric boundary layer. By the Clausius-Clapeyron relationship, warmer boundary layer air can hold more water vapor and thus results in more energetic storms. Changes in TC intensity are difficult to predict due to the presence of fine structures (e.g. convective structures and rainbands) with length scales of less than 1 km, while general circulation models (GCMs) generally have horizontal resolutions of tens of kilometers. The models are therefore unable to capture these features, which are critical to accurately simulating cyclone structure and intensity. Further, strong TCs are rare events, meaning that long multi-decadal simulations are necessary to generate meaningful statistics about intense TC activity. This adds to the computational expense, making it yet more difficult to generate accurate statistics about long-term changes in TC intensity due to global warming via direct simulation. We take an alternative approach, applying action minimization techniques developed in molecular dynamics to the WRF weather/climate model. We construct artificial model trajectories that lead from quiescent (TC-free) states to TC states, then minimize the deviation of these trajectories from true model dynamics. We can thus create Monte Carlo model ensembles that are biased towards cyclogenesis, which reduces computational expense by limiting time spent in non-TC states. This allows for: 1) selective interrogation of model states with TCs; 2) finding the likeliest paths for
Guidelines for mixed waste minimization
International Nuclear Information System (INIS)
Owens, C.
1992-02-01
Currently, there is no commercial mixed waste disposal available in the United States. Storage and treatment for commercial mixed waste is limited. Host States and compacts region officials are encouraging their mixed waste generators to minimize their mixed wastes because of management limitations. This document provides a guide to mixed waste minimization
Directory of Open Access Journals (Sweden)
Knol Dirk L
2006-08-01
Full Text Available Abstract Changes in scores on health status questionnaires are difficult to interpret. Several methods to determine minimally important changes (MICs have been proposed which can broadly be divided in distribution-based and anchor-based methods. Comparisons of these methods have led to insight into essential differences between these approaches. Some authors have tried to come to a uniform measure for the MIC, such as 0.5 standard deviation and the value of one standard error of measurement (SEM. Others have emphasized the diversity of MIC values, depending on the type of anchor, the definition of minimal importance on the anchor, and characteristics of the disease under study. A closer look makes clear that some distribution-based methods have been merely focused on minimally detectable changes. For assessing minimally important changes, anchor-based methods are preferred, as they include a definition of what is minimally important. Acknowledging the distinction between minimally detectable and minimally important changes is useful, not only to avoid confusion among MIC methods, but also to gain information on two important benchmarks on the scale of a health status measurement instrument. Appreciating the distinction, it becomes possible to judge whether the minimally detectable change of a measurement instrument is sufficiently small to detect minimally important changes.
The non-minimal heterotic pure spinor string in a curved background
Energy Technology Data Exchange (ETDEWEB)
Chandia, Osvaldo [Facultad de Artes Liberales and Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez,Diagonal Las Torres 2640, Peñalolén, Santiago (Chile)
2014-03-21
We study the non-minimal pure spinor string in a curved background. We find that the minimal BRST invariance implies the existence of a non-trivial stress-energy tensor for the minimal and non-minimal variables in the heterotic curved background. We find constraint equations for the b ghost. We construct the b ghost as a solution of these constraints.
Waste minimization handbook, Volume 1
International Nuclear Information System (INIS)
Boing, L.E.; Coffey, M.J.
1995-12-01
This technical guide presents various methods used by industry to minimize low-level radioactive waste (LLW) generated during decommissioning and decontamination (D and D) activities. Such activities generate significant amounts of LLW during their operations. Waste minimization refers to any measure, procedure, or technique that reduces the amount of waste generated during a specific operation or project. Preventive waste minimization techniques implemented when a project is initiated can significantly reduce waste. Techniques implemented during decontamination activities reduce the cost of decommissioning. The application of waste minimization techniques is not limited to D and D activities; it is also useful during any phase of a facility's life cycle. This compendium will be supplemented with a second volume of abstracts of hundreds of papers related to minimizing low-level nuclear waste. This second volume is expected to be released in late 1996
Waste minimization handbook, Volume 1
Energy Technology Data Exchange (ETDEWEB)
Boing, L.E.; Coffey, M.J.
1995-12-01
This technical guide presents various methods used by industry to minimize low-level radioactive waste (LLW) generated during decommissioning and decontamination (D and D) activities. Such activities generate significant amounts of LLW during their operations. Waste minimization refers to any measure, procedure, or technique that reduces the amount of waste generated during a specific operation or project. Preventive waste minimization techniques implemented when a project is initiated can significantly reduce waste. Techniques implemented during decontamination activities reduce the cost of decommissioning. The application of waste minimization techniques is not limited to D and D activities; it is also useful during any phase of a facility`s life cycle. This compendium will be supplemented with a second volume of abstracts of hundreds of papers related to minimizing low-level nuclear waste. This second volume is expected to be released in late 1996.
Minimal Webs in Riemannian Manifolds
DEFF Research Database (Denmark)
Markvorsen, Steen
2008-01-01
For a given combinatorial graph $G$ a {\\it geometrization} $(G, g)$ of the graph is obtained by considering each edge of the graph as a $1-$dimensional manifold with an associated metric $g$. In this paper we are concerned with {\\it minimal isometric immersions} of geometrized graphs $(G, g......)$ into Riemannian manifolds $(N^{n}, h)$. Such immersions we call {\\em{minimal webs}}. They admit a natural 'geometric' extension of the intrinsic combinatorial discrete Laplacian. The geometric Laplacian on minimal webs enjoys standard properties such as the maximum principle and the divergence theorems, which...... are of instrumental importance for the applications. We apply these properties to show that minimal webs in ambient Riemannian spaces share several analytic and geometric properties with their smooth (minimal submanifold) counterparts in such spaces. In particular we use appropriate versions of the divergence...
Robertson, William C
2002-01-01
Confounded by kinetic energy? Suspect that teaching about simple machines isn t really so simple? Exasperated by electricity? If you fear the study of energy is beyond you, this entertaining book will do more than introduce you to the topic. It will help you actually understand it. At the book s heart are easy-to-grasp explanations of energy basics work, kinetic energy, potential energy, and the transformation of energy and energy as it relates to simple machines, heat energy, temperature, and heat transfer. Irreverent author Bill Robertson suggests activities that bring the basic concepts of energy to life with common household objects. Each chapter ends with a summary and an applications section that uses practical examples such as roller coasters and home heating systems to explain energy transformations and convection cells. The final chapter brings together key concepts in an easy-to-grasp explanation of how electricity is generated. Energy is the second book in the Stop Faking It! series published by NS...
Minimal Poems Written in 1979 Minimal Poems Written in 1979
Directory of Open Access Journals (Sweden)
Sandra Sirangelo Maggio
2008-04-01
Full Text Available The reading of M. van der Slice's Minimal Poems Written in 1979 (the work, actually, has no title reminded me of a book I have seen a long time ago. called Truth, which had not even a single word printed inside. In either case we have a sample of how often excentricities can prove efficient means of artistic creativity, in this new literary trend known as Minimalism. The reading of M. van der Slice's Minimal Poems Written in 1979 (the work, actually, has no title reminded me of a book I have seen a long time ago. called Truth, which had not even a single word printed inside. In either case we have a sample of how often excentricities can prove efficient means of artistic creativity, in this new literary trend known as Minimalism.
A random energy model for size dependence : recurrence vs. transience
Külske, Christof
1998-01-01
We investigate the size dependence of disordered spin models having an infinite number of Gibbs measures in the framework of a simplified 'random energy model for size dependence'. We introduce two versions (involving either independent random walks or branching processes), that can be seen as
Minimal Flavour Violation and Beyond
Isidori, Gino
2012-01-01
We review the formulation of the Minimal Flavour Violation (MFV) hypothesis in the quark sector, as well as some "variations on a theme" based on smaller flavour symmetry groups and/or less minimal breaking terms. We also review how these hypotheses can be tested in B decays and by means of other flavour-physics observables. The phenomenological consequences of MFV are discussed both in general terms, employing a general effective theory approach, and in the specific context of the Minimal Supersymmetric extension of the SM.
Minimizing waste in environmental restoration
International Nuclear Information System (INIS)
Thuot, J.R.; Moos, L.
1996-01-01
Environmental restoration, decontamination and decommissioning, and facility dismantlement projects are not typically known for their waste minimization and pollution prevention efforts. Typical projects are driven by schedules and milestones with little attention given to cost or waste minimization. Conventional wisdom in these projects is that the waste already exists and cannot be reduced or minimized; however, there are significant areas where waste and cost can be reduced by careful planning and execution. Waste reduction can occur in three ways: beneficial reuse or recycling, segregation of waste types, and reducing generation of secondary waste
Minimizing waste in environmental restoration
International Nuclear Information System (INIS)
Moos, L.; Thuot, J.R.
1996-01-01
Environmental restoration, decontamination and decommissioning and facility dismantelment projects are not typically known for their waste minimization and pollution prevention efforts. Typical projects are driven by schedules and milestones with little attention given to cost or waste minimization. Conventional wisdom in these projects is that the waste already exists and cannot be reduced or minimized. In fact, however, there are three significant areas where waste and cost can be reduced. Waste reduction can occur in three ways: beneficial reuse or recycling; segregation of waste types; and reducing generation of secondary waste. This paper will discuss several examples of reuse, recycle, segregation, and secondary waste reduction at ANL restoration programs
Subspace Correction Methods for Total Variation and $\\ell_1$-Minimization
Fornasier, Massimo
2009-01-01
This paper is concerned with the numerical minimization of energy functionals in Hilbert spaces involving convex constraints coinciding with a seminorm for a subspace. The optimization is realized by alternating minimizations of the functional on a sequence of orthogonal subspaces. On each subspace an iterative proximity-map algorithm is implemented via oblique thresholding, which is the main new tool introduced in this work. We provide convergence conditions for the algorithm in order to compute minimizers of the target energy. Analogous results are derived for a parallel variant of the algorithm. Applications are presented in domain decomposition methods for degenerate elliptic PDEs arising in total variation minimization and in accelerated sparse recovery algorithms based on 1-minimization. We include numerical examples which show e.cient solutions to classical problems in signal and image processing. © 2009 Society for Industrial and Applied Physics.
National Institutes of Health: Mixed waste minimization and treatment
Energy Technology Data Exchange (ETDEWEB)
NONE
1995-08-01
The Appalachian States Low-Level Radioactive Waste Commission requested the US Department of Energy`s National Low-Level Waste Management Program (NLLWMP) to assist the biomedical community in becoming more knowledgeable about its mixed waste streams, to help minimize the mixed waste stream generated by the biomedical community, and to identify applicable treatment technologies for these mixed waste streams. As the first step in the waste minimization process, liquid low-level radioactive mixed waste (LLMW) streams generated at the National Institutes of Health (NIH) were characterized and combined into similar process categories. This report identifies possible waste minimization and treatment approaches for the LLMW generated by the biomedical community identified in DOE/LLW-208. In development of the report, on site meetings were conducted with NIH personnel responsible for generating each category of waste identified as lacking disposal options. Based on the meetings and general waste minimization guidelines, potential waste minimization options were identified.
International Nuclear Information System (INIS)
1975-10-01
On the occasion of the World Environment Day the Norwegian Ministry for the Environment held a conference on growth problems in energy consumption. The themes which were treated were energy conservation, hydroelectric power, the role of nuclear power, radioactive waste disposal, fossil fuel resources, ecological limits, pollution and international aspects. Nuclear energy forms the main theme of one lecture and an aspect of several others. (JIW)
Torriti, Jacopo
2016-01-01
The impact of energy policy measures has been assessed with various appraisal and evaluation tools since the 1960s. Decision analysis, environmental impact assessment and strategic environmental assessment are all notable examples of progenitors of Regulatory Impact Assessment (RIA) in the assessment of energy policies, programmes and projects. This chapter provides overview of policy tools which have been historically applied to assess the impacts of energy policies, programmes and projects....
International Nuclear Information System (INIS)
2003-01-01
In the framework of the National Debate on the energies in a context of a sustainable development some associations for the environment organized a debate on the nuclear interest facing the renewable energies. The first part presents the nuclear energy as a possible solution to fight against the greenhouse effect and the associated problem of the wastes management. The second part gives information on the solar energy and the possibilities of heat and electric power production. A presentation of the FEE (French wind power association) on the situation and the development of the wind power in France, is also provided. (A.L.B.)
Sludge minimization technologies - an overview
Energy Technology Data Exchange (ETDEWEB)
Oedegaard, Hallvard
2003-07-01
The management of wastewater sludge from wastewater treatment plants represents one of the major challenges in wastewater treatment today. The cost of the sludge treatment amounts to more that the cost of the liquid in many cases. Therefore the focus on and interest in sludge minimization is steadily increasing. In the paper an overview is given for sludge minimization (sludge mass reduction) options. It is demonstrated that sludge minimization may be a result of reduced production of sludge and/or disintegration processes that may take place both in the wastewater treatment stage and in the sludge stage. Various sludge disintegration technologies for sludge minimization are discussed, including mechanical methods (focusing on stirred ball-mill, high-pressure homogenizer, ultrasonic disintegrator), chemical methods (focusing on the use of ozone), physical methods (focusing on thermal and thermal/chemical hydrolysis) and biological methods (focusing on enzymatic processes). (author)
Wilson loops in minimal surfaces
International Nuclear Information System (INIS)
Drukker, Nadav; Gross, David J.; Ooguri, Hirosi
1999-01-01
The AdS/CFT correspondence suggests that the Wilson loop of the large N gauge theory with N = 4 supersymmetry in 4 dimensions is described by a minimal surface in AdS 5 x S 5 . The authors examine various aspects of this proposal, comparing gauge theory expectations with computations of minimal surfaces. There is a distinguished class of loops, which the authors call BPS loops, whose expectation values are free from ultra-violet divergence. They formulate the loop equation for such loops. To the extent that they have checked, the minimal surface in AdS 5 x S 5 gives a solution of the equation. The authors also discuss the zig-zag symmetry of the loop operator. In the N = 4 gauge theory, they expect the zig-zag symmetry to hold when the loop does not couple the scalar fields in the supermultiplet. They will show how this is realized for the minimal surface
Classical strings and minimal surfaces
International Nuclear Information System (INIS)
Urbantke, H.
1986-01-01
Real Lorentzian forms of some complex or complexified Euclidean minimal surfaces are obtained as an application of H.A. Schwarz' solution to the initial value problem or a search for surfaces admitting a group of Poincare transformations. (Author)
International Nuclear Information System (INIS)
Przyjalkowski, V V
2008-01-01
We construct an abstract theory of Gromov-Witten invariants of genus 0 for quantum minimal Fano varieties (a minimal class of varieties which is natural from the quantum cohomological viewpoint). Namely, we consider the minimal Gromov-Witten ring: a commutative algebra whose generators and relations are of the form used in the Gromov-Witten theory of Fano varieties (of unspecified dimension). The Gromov-Witten theory of any quantum minimal variety is a homomorphism from this ring to C. We prove an abstract reconstruction theorem which says that this ring is isomorphic to the free commutative ring generated by 'prime two-pointed invariants'. We also find solutions of the differential equation of type DN for a Fano variety of dimension N in terms of the generating series of one-pointed Gromov-Witten invariants
Wilson loops and minimal surfaces
International Nuclear Information System (INIS)
Drukker, Nadav; Gross, David J.; Ooguri, Hirosi
1999-01-01
The AdS-CFT correspondence suggests that the Wilson loop of the large N gauge theory with N=4 supersymmetry in four dimensions is described by a minimal surface in AdS 5 xS 5 . We examine various aspects of this proposal, comparing gauge theory expectations with computations of minimal surfaces. There is a distinguished class of loops, which we call BPS loops, whose expectation values are free from ultraviolet divergence. We formulate the loop equation for such loops. To the extent that we have checked, the minimal surface in AdS 5 xS 5 gives a solution of the equation. We also discuss the zigzag symmetry of the loop operator. In the N=4 gauge theory, we expect the zigzag symmetry to hold when the loop does not couple the scalar fields in the supermultiplet. We will show how this is realized for the minimal surface. (c) 1999 The American Physical Society
Minimal string theory is logarithmic
International Nuclear Information System (INIS)
Ishimoto, Yukitaka; Yamaguchi, Shun-ichi
2005-01-01
We study the simplest examples of minimal string theory whose worldsheet description is the unitary (p,q) minimal model coupled to two-dimensional gravity ( Liouville field theory). In the Liouville sector, we show that four-point correlation functions of 'tachyons' exhibit logarithmic singularities, and that the theory turns out to be logarithmic. The relation with Zamolodchikov's logarithmic degenerate fields is also discussed. Our result holds for generic values of (p,q)
A perturbation technique for shield weight minimization
International Nuclear Information System (INIS)
Watkins, E.F.; Greenspan, E.
1993-01-01
The radiation shield optimization code SWAN (Ref. 1) was originally developed for minimizing the thickness of a shield that will meet a given dose (or another) constraint or for extremizing a performance parameter of interest (e.g., maximizing energy multiplication or minimizing dose) while maintaining the shield volume constraint. The SWAN optimization process proved to be highly effective (e.g., see Refs. 2, 3, and 4). The purpose of this work is to investigate the applicability of the SWAN methodology to problems in which the weight rather than the volume is the relevant shield characteristic. Such problems are encountered in shield design for space nuclear power systems. The investigation is carried out using SWAN with the coupled neutron-photon cross-section library FLUNG (Ref. 5)
Investigations on quantum mechanics with minimal length
International Nuclear Information System (INIS)
Chargui, Yassine
2009-01-01
We consider a modified quantum mechanics where the coordinates and momenta are assumed to satisfy a non-standard commutation relation of the form( X i , P j ) = iℎ(δ ij (1+βP 2 )+β'P i P j ). Such an algebra results in a generalized uncertainty relation which leads to the existence of a minimal observable length. Moreover, it incorporates an UV/IR mixing and non commutative position space. We analyse the possible representations in terms of differential operators. The latter are used to study the low energy effects of the minimal length by considering different quantum systems : the harmonic oscillator, the Klein-Gordon oscillator, the spinless Salpeter Coulomb problem, and the Dirac equation with a linear confining potential. We also discuss whether such effects are observable in precision measurements on a relativistic electron trapped in strong magnetic field.
Directory of Open Access Journals (Sweden)
Zohreh Yousefi
2016-11-01
Full Text Available Introduction Small ruminants, especially native breed types, play an important role in livelihoods of a considerable part of human population in the tropics from socio-economic aspects. Therefore, integrated attempt in terms of management and genetic improvement to enhance production is of crucial importance. Knowledge of genetic variation and co-variation among traits is required for both the design of effective sheep breeding programs and the accurate prediction of genetic progress from these programs. Body weight and growth traits are one of the economically important traits in sheep production, especially in Iran where lamb sale is the main source of income for sheep breeders while other products are in secondary importance. Although mutton is the most important source of protein in Iran, meat production from the sheep does not cover the increasing consumer demand. On the other hand, increase in sheep number to increase meat production has been limited by low quality and quantity of forage range. Therefore, enhancing meat production should be achieved by selecting the animals that have maximum genetic merit as next generation parents. To design an efficient improvement program and genetic evaluation system for maximization response to selection for economically important traits, accurate estimates of the genetic parameters and the genetic relationships between the traits are necessary. Studies of various sheep breeds have shown that both direct and maternal genetic influences are of importance for lamb growth. When growth traits are included in the breeding goal, both direct and maternal genetic effects should be taken into account in order to achieve optimum genetic progress. The objective of this study was to estimate the variance components and heritability, for growth traits, by fitting six animal models in the Sangsari sheep using Gibbs sampling. Material and Method Sangsari is a fat-tailed and relatively small sized breed of sheep
Starr, Francis W; Douglas, Jack F; Sastry, Srikanth
2013-03-28
We carefully examine common measures of dynamical heterogeneity for a model polymer melt and test how these scales compare with those hypothesized by the Adam and Gibbs (AG) and random first-order transition (RFOT) theories of relaxation in glass-forming liquids. To this end, we first analyze clusters of highly mobile particles, the string-like collective motion of these mobile particles, and clusters of relative low mobility. We show that the time scale of the high-mobility clusters and strings is associated with a diffusive time scale, while the low-mobility particles' time scale relates to a structural relaxation time. The difference of the characteristic times for the high- and low-mobility particles naturally explains the well-known decoupling of diffusion and structural relaxation time scales. Despite the inherent difference of dynamics between high- and low-mobility particles, we find a high degree of similarity in the geometrical structure of these particle clusters. In particular, we show that the fractal dimensions of these clusters are consistent with those of swollen branched polymers or branched polymers with screened excluded-volume interactions, corresponding to lattice animals and percolation clusters, respectively. In contrast, the fractal dimension of the strings crosses over from that of self-avoiding walks for small strings, to simple random walks for longer, more strongly interacting, strings, corresponding to flexible polymers with screened excluded-volume interactions. We examine the appropriateness of identifying the size scales of either mobile particle clusters or strings with the size of cooperatively rearranging regions (CRR) in the AG and RFOT theories. We find that the string size appears to be the most consistent measure of CRR for both the AG and RFOT models. Identifying strings or clusters with the "mosaic" length of the RFOT model relaxes the conventional assumption that the "entropic droplets" are compact. We also confirm the
Waste minimization applications at a remediation site
International Nuclear Information System (INIS)
Allmon, L.A.
1995-01-01
The Fernald Environmental Management Project (FEMP) owned by the Department of Energy was used for the processing of uranium. In 1989 Fernald suspended production of uranium metals and was placed on the National Priorities List (NPL). The site's mission has changed from one of production to environmental restoration. Many groups necessary for producing a product were deemed irrelevant for remediation work, including Waste Minimization. Waste Minimization does not readily appear to be applicable to remediation work. Environmental remediation is designed to correct adverse impacts to the environment from past operations and generates significant amounts of waste requiring management. The premise of pollution prevention is to avoid waste generation, thus remediation is in direct conflict with this premise. Although greater amounts of waste will be generated during environmental remediation, treatment capacities are not always available and disposal is becoming more difficult and costly. This creates the need for pollution prevention and waste minimization. Applying waste minimization principles at a remediation site is an enormous challenge. If the remediation site is also radiologically contaminated it is even a bigger challenge. Innovative techniques and ideas must be utilized to achieve reductions in the amount of waste that must be managed or dispositioned. At Fernald the waste minimization paradigm was shifted from focusing efforts on source reduction to focusing efforts on recycle/reuse by inverting the EPA waste management hierarchy. A fundamental difference at remediation sites is that source reduction has limited applicability to legacy wastes but can be applied successfully on secondary waste generation. The bulk of measurable waste reduction will be achieved by the recycle/reuse of primary wastes and by segregation and decontamination of secondary wastestreams. Each effort must be measured in terms of being economically and ecologically beneficial
On the interfacial energy of coherent interfaces
International Nuclear Information System (INIS)
Kaptay, G.
2012-01-01
A thermodynamic model has been developed for interfacial energies of coherent interfaces using only the molar Gibbs energy and the molar volume of the two phases surrounding the interface as the initial data. The analysis is started from the simplest case of the interface formed by two solutions on the two sides of a miscibility gap, when both phases are described by the same Gibbs energy and molar volume functions. This method is applied to the fcc Au–Ni, liquid Ga–Pb and liquid Al–Bi systems. Reasonable agreement was found with the measured values in liquid Ga–Pb and Al–Bi systems. It was shown that the calculated results are sensitive to the choice of the Calphad-estimated thermodynamic data. The method is extended to the case where the two phases are described by different Gibbs energy and molar volume functions. The extended model is applied to the interface present in an Ni-based superalloy between the AlNi 3 face-centered cubic (fcc) compound and the Ni–Al fcc disordered solid solution. The calculated results are found to be similar to other values recently obtained from the combination of kinetic and thermodynamic data. The method is extended to ternary and higher order systems. It is predicted that the interfacial energy will gradually decrease with the increase in number of components in the system.
Minimal and non-minimal standard models: Universality of radiative corrections
International Nuclear Information System (INIS)
Passarino, G.
1991-01-01
The possibility of describing electroweak processes by means of models with a non-minimal Higgs sector is analyzed. The renormalization procedure which leads to a set of fitting equations for the bare parameters of the lagrangian is first reviewed for the minimal standard model. A solution of the fitting equations is obtained, which correctly includes large higher-order corrections. Predictions for physical observables, notably the W boson mass and the Z O partial widths, are discussed in detail. Finally the extension to non-minimal models is described under the assumption that new physics will appear only inside the vector boson self-energies and the concept of universality of radiative corrections is introduced, showing that to a large extent they are insensitive to the details of the enlarged Higgs sector. Consequences for the bounds on the top quark mass are also discussed. (orig.)
Impact of Wire Geometry in Energy Extraction from Salinity Differences Using Capacitive Technology
Sales, B.B.; Burheim, O.S.; Liu, F.; Schaetzle, O.; Buisman, C.J.N.; Hamelers, H.V.M.
2012-01-01
Energy extraction based on capacitive Donnan potential (CDP) is a recently suggested technique for sustainable power generation. CDP combines the use of ion-exchange membranes and porous carbon electrodes to convert the Gibbs free energy of mixing sea and river water into electric work. The
Yip, N.Y.; Vermaas, D.A.; Nijmeijer, K.; Elimelech, M.
2014-01-01
Reverse electrodialysis (RED) can harness the Gibbs free energy of mixing when fresh river water flows into the sea for sustainable power generation. In this study, we carry out a thermodynamic and energy efficiency analysis of RED power generation, and assess the membrane power density. First, we
Minimal but non-minimal inflation and electroweak symmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Marzola, Luca [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Institute of Physics, University of Tartu,Ravila 14c, 50411 Tartu (Estonia); Racioppi, Antonio [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia)
2016-10-07
We consider the most minimal scale invariant extension of the standard model that allows for successful radiative electroweak symmetry breaking and inflation. The framework involves an extra scalar singlet, that plays the rôle of the inflaton, and is compatibile with current experimental bounds owing to the non-minimal coupling of the latter to gravity. This inflationary scenario predicts a very low tensor-to-scalar ratio r≈10{sup −3}, typical of Higgs-inflation models, but in contrast yields a scalar spectral index n{sub s}≃0.97 which departs from the Starobinsky limit. We briefly discuss the collider phenomenology of the framework.
Pethica, Brian A
2007-12-21
As indicated by Gibbs and made explicit by Guggenheim, the electrical potential difference between two regions of different chemical composition cannot be measured. The Gibbs-Guggenheim Principle restricts the use of classical electrostatics in electrochemical theories as thermodynamically unsound with some few approximate exceptions, notably for dilute electrolyte solutions and concomitant low potentials where the linear limit for the exponential of the relevant Boltzmann distribution applies. The Principle invalidates the widespread use of forms of the Poisson-Boltzmann equation which do not include the non-electrostatic components of the chemical potentials of the ions. From a thermodynamic analysis of the parallel plate electrical condenser, employing only measurable electrical quantities and taking into account the chemical potentials of the components of the dielectric and their adsorption at the surfaces of the condenser plates, an experimental procedure to provide exceptions to the Principle has been proposed. This procedure is now reconsidered and rejected. No other related experimental procedures circumvent the Principle. Widely-used theoretical descriptions of electrolyte solutions, charged surfaces and colloid dispersions which neglect the Principle are briefly discussed. MD methods avoid the limitations of the Poisson-Bolzmann equation. Theoretical models which include the non-electrostatic components of the inter-ion and ion-surface interactions in solutions and colloid systems assume the additivity of dispersion and electrostatic forces. An experimental procedure to test this assumption is identified from the thermodynamics of condensers at microscopic plate separations. The available experimental data from Kelvin probe studies are preliminary, but tend against additivity. A corollary to the Gibbs-Guggenheim Principle is enunciated, and the Principle is restated that for any charged species, neither the difference in electrostatic potential nor the
Minimal modification to tribimaximal mixing
International Nuclear Information System (INIS)
He Xiaogang; Zee, A.
2011-01-01
We explore some ways of minimally modifying the neutrino mixing matrix from tribimaximal, characterized by introducing at most one mixing angle and a CP violating phase thus extending our earlier work. One minimal modification, motivated to some extent by group theoretic considerations, is a simple case with the elements V α2 of the second column in the mixing matrix equal to 1/√(3). Modifications by keeping one of the columns or one of the rows unchanged from tribimaximal mixing all belong to the class of minimal modification. Some of the cases have interesting experimentally testable consequences. In particular, the T2K and MINOS collaborations have recently reported indications of a nonzero θ 13 . For the cases we consider, the new data sharply constrain the CP violating phase angle δ, with δ close to 0 (in some cases) and π disfavored.
Topological gravity with minimal matter
International Nuclear Information System (INIS)
Li Keke
1991-01-01
Topological minimal matter, obtained by twisting the minimal N = 2 supeconformal field theory, is coupled to two-dimensional topological gravity. The free field formulation of the coupled system allows explicit representations of BRST charge, physical operators and their correlation functions. The contact terms of the physical operators may be evaluated by extending the argument used in a recent solution of topological gravity without matter. The consistency of the contact terms in correlation functions implies recursion relations which coincide with the Virasoro constraints derived from the multi-matrix models. Topological gravity with minimal matter thus provides the field theoretic description for the multi-matrix models of two-dimensional quantum gravity. (orig.)
Minimal Marking: A Success Story
Directory of Open Access Journals (Sweden)
Anne McNeilly
2014-11-01
Full Text Available The minimal-marking project conducted in Ryerson’s School of Journalism throughout 2012 and early 2013 resulted in significantly higher grammar scores in two first-year classes of minimally marked university students when compared to two traditionally marked classes. The “minimal-marking” concept (Haswell, 1983, which requires dramatically more student engagement, resulted in more successful learning outcomes for surface-level knowledge acquisition than the more traditional approach of “teacher-corrects-all.” Results suggest it would be effective, not just for grammar, punctuation, and word usage, the objective here, but for any material that requires rote-memory learning, such as the Associated Press or Canadian Press style rules used by news publications across North America.
Minimality of critical scenarios with linear logic and cutsets
African Journals Online (AJOL)
DK
Keywords: Dependability - Mechatronic systems -Petri net - Linear logic - Minimal Feared scenarios - Cutsets. ..... Energy supply. Detection high level. Relay. ET. Energy supply. Detection high level. Relay ..... Evaluation de la SdF des systèmes mécatroniques en utilisant ... in complex distributed systems, Proceedings of the.
Minimizing fuel wood consumption through the evolution of hot ston ...
African Journals Online (AJOL)
The central objective of this paper is to minimize fuelwood consumption through evolving alternative domestic energy. Data on alternative domestic energy sources, and use fuel wood consumption during scarcity of petroleum were collected using structured questionnaires. Data on time spent to cook yam, race and beans ...
Minimizing water consumption when producing hydropower
Leon, A. S.
2015-12-01
In 2007, hydropower accounted for only 16% of the world electricity production, with other renewable sources totaling 3%. Thus, it is not surprising that when alternatives are evaluated for new energy developments, there is strong impulse for fossil fuel or nuclear energy as opposed to renewable sources. However, as hydropower schemes are often part of a multipurpose water resources development project, they can often help to finance other components of the project. In addition, hydropower systems and their associated dams and reservoirs provide human well-being benefits, such as flood control and irrigation, and societal benefits such as increased recreational activities and improved navigation. Furthermore, hydropower due to its associated reservoir storage, can provide flexibility and reliability for energy production in integrated energy systems. The storage capability of hydropower systems act as a regulating mechanism by which other intermittent and variable renewable energy sources (wind, wave, solar) can play a larger role in providing electricity of commercial quality. Minimizing water consumption for producing hydropower is critical given that overuse of water for energy production may result in a shortage of water for other purposes such as irrigation, navigation or fish passage. This paper presents a dimensional analysis for finding optimal flow discharge and optimal penstock diameter when designing impulse and reaction water turbines for hydropower systems. The objective of this analysis is to provide general insights for minimizing water consumption when producing hydropower. This analysis is based on the geometric and hydraulic characteristics of the penstock, the total hydraulic head and the desired power production. As part of this analysis, various dimensionless relationships between power production, flow discharge and head losses were derived. These relationships were used to withdraw general insights on determining optimal flow discharge and
Non-minimal inflation revisited
International Nuclear Information System (INIS)
Nozari, Kourosh; Shafizadeh, Somayeh
2010-01-01
We reconsider an inflationary model that inflaton field is non-minimally coupled to gravity. We study the parameter space of the model up to the second (and in some cases third) order of the slow-roll parameters. We calculate inflation parameters in both Jordan and Einstein frames, and the results are compared in these two frames and also with observations. Using the recent observational data from combined WMAP5+SDSS+SNIa datasets, we study constraints imposed on our model parameters, especially the non-minimal coupling ξ.