WorldWideScience

Sample records for pointwise energy conditions

  1. Energy-pointwise discrete ordinates transport methods

    International Nuclear Information System (INIS)

    Williams, M.L.; Asgari, M.; Tashakorri, R.

    1997-01-01

    A very brief description is given of a one-dimensional code, CENTRM, which computes a detailed, space-dependent flux spectrum in a pointwise-energy representation within the resolved resonance range. The code will become a component in the SCALE system to improve computation of self-shielded cross sections, thereby enhancing the accuracy of codes such as KENO. CENTRM uses discrete-ordinates transport theory with an arbitrary angular quadrature order and a Legendre expansion of scattering anisotropy for moderator materials and heavy nuclides. The CENTRM program provides capability to deterministically compute full energy range, space-dependent angular flux spectra, rigorously accounting for resonance fine-structure and scattering anisotropy effects

  2. Pointwise second-order necessary optimality conditions and second-order sensitivity relations in optimal control

    Science.gov (United States)

    Frankowska, Hélène; Hoehener, Daniel

    2017-06-01

    This paper is devoted to pointwise second-order necessary optimality conditions for the Mayer problem arising in optimal control theory. We first show that with every optimal trajectory it is possible to associate a solution p (ṡ) of the adjoint system (as in the Pontryagin maximum principle) and a matrix solution W (ṡ) of an adjoint matrix differential equation that satisfy a second-order transversality condition and a second-order maximality condition. These conditions seem to be a natural second-order extension of the maximum principle. We then prove a Jacobson like necessary optimality condition for general control systems and measurable optimal controls that may be only ;partially singular; and may take values on the boundary of control constraints. Finally we investigate the second-order sensitivity relations along optimal trajectories involving both p (ṡ) and W (ṡ).

  3. Theory and application of deterministic multidimensional pointwise energy lattice physics methods

    International Nuclear Information System (INIS)

    Zerkle, M.L.

    1999-01-01

    The theory and application of deterministic, multidimensional, pointwise energy lattice physics methods are discussed. These methods may be used to solve the neutron transport equation in multidimensional geometries using near-continuous energy detail to calculate equivalent few-group diffusion theory constants that rigorously account for spatial and spectral self-shielding effects. A dual energy resolution slowing down algorithm is described which reduces the computer memory and disk storage requirements for the slowing down calculation. Results are presented for a 2D BWR pin cell depletion benchmark problem

  4. Pointwise convergence of Fourier series

    CERN Document Server

    Arias de Reyna, Juan

    2002-01-01

    This book contains a detailed exposition of Carleson-Hunt theorem following the proof of Carleson: to this day this is the only one giving better bounds. It points out the motivation of every step in the proof. Thus the Carleson-Hunt theorem becomes accessible to any analyst.The book also contains the first detailed exposition of the fine results of Hunt, Sjölin, Soria, etc on the convergence of Fourier Series. Its final chapters present original material. With both Fefferman's proof and the recent one of Lacey and Thiele in print, it becomes more important than ever to understand and compare these two related proofs with that of Carleson and Hunt. These alternative proofs do not yield all the results of the Carleson-Hunt proof. The intention of this monograph is to make Carleson's proof accessible to a wider audience, and to explain its consequences for the pointwise convergence of Fourier series for functions in spaces near $äcal Lü^1$, filling a well-known gap in the literature.

  5. Quantitative Pointwise Estimate of the Solution of the Linearized Boltzmann Equation

    Science.gov (United States)

    Lin, Yu-Chu; Wang, Haitao; Wu, Kung-Chien

    2018-04-01

    We study the quantitative pointwise behavior of the solutions of the linearized Boltzmann equation for hard potentials, Maxwellian molecules and soft potentials, with Grad's angular cutoff assumption. More precisely, for solutions inside the finite Mach number region (time like region), we obtain the pointwise fluid structure for hard potentials and Maxwellian molecules, and optimal time decay in the fluid part and sub-exponential time decay in the non-fluid part for soft potentials. For solutions outside the finite Mach number region (space like region), we obtain sub-exponential decay in the space variable. The singular wave estimate, regularization estimate and refined weighted energy estimate play important roles in this paper. Our results extend the classical results of Liu and Yu (Commun Pure Appl Math 57:1543-1608, 2004), (Bull Inst Math Acad Sin 1:1-78, 2006), (Bull Inst Math Acad Sin 6:151-243, 2011) and Lee et al. (Commun Math Phys 269:17-37, 2007) to hard and soft potentials by imposing suitable exponential velocity weight on the initial condition.

  6. Quantitative Pointwise Estimate of the Solution of the Linearized Boltzmann Equation

    Science.gov (United States)

    Lin, Yu-Chu; Wang, Haitao; Wu, Kung-Chien

    2018-06-01

    We study the quantitative pointwise behavior of the solutions of the linearized Boltzmann equation for hard potentials, Maxwellian molecules and soft potentials, with Grad's angular cutoff assumption. More precisely, for solutions inside the finite Mach number region (time like region), we obtain the pointwise fluid structure for hard potentials and Maxwellian molecules, and optimal time decay in the fluid part and sub-exponential time decay in the non-fluid part for soft potentials. For solutions outside the finite Mach number region (space like region), we obtain sub-exponential decay in the space variable. The singular wave estimate, regularization estimate and refined weighted energy estimate play important roles in this paper. Our results extend the classical results of Liu and Yu (Commun Pure Appl Math 57:1543-1608, 2004), (Bull Inst Math Acad Sin 1:1-78, 2006), (Bull Inst Math Acad Sin 6:151-243, 2011) and Lee et al. (Commun Math Phys 269:17-37, 2007) to hard and soft potentials by imposing suitable exponential velocity weight on the initial condition.

  7. Pointwise probability reinforcements for robust statistical inference.

    Science.gov (United States)

    Frénay, Benoît; Verleysen, Michel

    2014-02-01

    Statistical inference using machine learning techniques may be difficult with small datasets because of abnormally frequent data (AFDs). AFDs are observations that are much more frequent in the training sample that they should be, with respect to their theoretical probability, and include e.g. outliers. Estimates of parameters tend to be biased towards models which support such data. This paper proposes to introduce pointwise probability reinforcements (PPRs): the probability of each observation is reinforced by a PPR and a regularisation allows controlling the amount of reinforcement which compensates for AFDs. The proposed solution is very generic, since it can be used to robustify any statistical inference method which can be formulated as a likelihood maximisation. Experiments show that PPRs can be easily used to tackle regression, classification and projection: models are freed from the influence of outliers. Moreover, outliers can be filtered manually since an abnormality degree is obtained for each observation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Energy conditions and spacetime singularities

    International Nuclear Information System (INIS)

    Tipler, F.J.

    1978-01-01

    In this paper, a number of theorems are proven which collectively show that singularities will occur in spacetime under weaker energy conditions than the strong energy condition. In particular, the Penrose theorem, which uses only the weak energy condition but which applies only to open universes, is extended to all closed universes which have a Cauchy surface whose universal covering manifold is not a three-sphere. Furthermore, it is shown that the strong energy condition in the Hawking-Penrose theorem can be replaced by the weak energy condition and the assumption that the strong energy condition holds only on the average. In addition, it is demonstrated that if the Universe is closed, then the existence of singularities follows from the averaged strong energy condition alone. It is argued that any globally hyperbolic spacetime which satisfies the weak energy condition and which contains a black hole must be null geodesically incomplete

  9. Rapid pointwise stabilization of vibrating strings and beams

    Directory of Open Access Journals (Sweden)

    Alia BARHOUMI

    2009-11-01

    Full Text Available Applying a general construction and using former results on the observability we prove, under rather general assumptions, a rapid pointwise stabilization of vibrating strings and beams.

  10. The undefined function differs from the pointwise undefined function

    OpenAIRE

    Dosch, Walter (Prof.)

    1993-01-01

    The undefined function differs from the pointwise undefined function. - In: Joint Conference on Declarative Programming : Proceedings / Maria I. Sessa ... (eds.). - Salerno : Univ. degli Studi, 1995. - S. 257-268

  11. Palatini wormholes and energy conditions from the prism of general relativity

    Energy Technology Data Exchange (ETDEWEB)

    Bejarano, Cecilia [Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Centro Mixto Universidad de Valencia-CSIC. Universidad de Valencia, Departamento de Fisica Teorica y IFIC, Valencia (Spain); Lobo, Francisco S.N.; Rubiera-Garcia, Diego [Faculdade de Ciencias da Universidade de Lisboa, Instituto de Astrofisica e Ciencias do Espaco, Lisbon (Portugal); Olmo, Gonzalo J. [Centro Mixto Universidad de Valencia-CSIC. Universidad de Valencia, Departamento de Fisica Teorica y IFIC, Valencia (Spain); Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil)

    2017-11-15

    Wormholes are hypothetical shortcuts in spacetime that in general relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard designer procedure frequently employed in the literature, arise directly from gravitational actions including additional terms resulting from contractions of the Ricci tensor with the metric, and which are formulated assuming independence between metric and connection (Palatini approach). We reinterpret such wormhole solutions under the prism of General Relativity and study the matter sources that thread them. We discuss the size of violation of the energy conditions in different cases and how this is related to the same spacetimes when viewed from the modified gravity side. (orig.)

  12. Palatini wormholes and energy conditions from the prism of general relativity.

    Science.gov (United States)

    Bejarano, Cecilia; Lobo, Francisco S N; Olmo, Gonzalo J; Rubiera-Garcia, Diego

    2017-01-01

    Wormholes are hypothetical shortcuts in spacetime that in general relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard designer procedure frequently employed in the literature, arise directly from gravitational actions including additional terms resulting from contractions of the Ricci tensor with the metric, and which are formulated assuming independence between metric and connection (Palatini approach). We reinterpret such wormhole solutions under the prism of General Relativity and study the matter sources that thread them. We discuss the size of violation of the energy conditions in different cases and how this is related to the same spacetimes when viewed from the modified gravity side.

  13. Enhancement of Visual Field Predictions with Pointwise Exponential Regression (PER) and Pointwise Linear Regression (PLR).

    Science.gov (United States)

    Morales, Esteban; de Leon, John Mark S; Abdollahi, Niloufar; Yu, Fei; Nouri-Mahdavi, Kouros; Caprioli, Joseph

    2016-03-01

    The study was conducted to evaluate threshold smoothing algorithms to enhance prediction of the rates of visual field (VF) worsening in glaucoma. We studied 798 patients with primary open-angle glaucoma and 6 or more years of follow-up who underwent 8 or more VF examinations. Thresholds at each VF location for the first 4 years or first half of the follow-up time (whichever was greater) were smoothed with clusters defined by the nearest neighbor (NN), Garway-Heath, Glaucoma Hemifield Test (GHT), and weighting by the correlation of rates at all other VF locations. Thresholds were regressed with a pointwise exponential regression (PER) model and a pointwise linear regression (PLR) model. Smaller root mean square error (RMSE) values of the differences between the observed and the predicted thresholds at last two follow-ups indicated better model predictions. The mean (SD) follow-up times for the smoothing and prediction phase were 5.3 (1.5) and 10.5 (3.9) years. The mean RMSE values for the PER and PLR models were unsmoothed data, 6.09 and 6.55; NN, 3.40 and 3.42; Garway-Heath, 3.47 and 3.48; GHT, 3.57 and 3.74; and correlation of rates, 3.59 and 3.64. Smoothed VF data predicted better than unsmoothed data. Nearest neighbor provided the best predictions; PER also predicted consistently more accurately than PLR. Smoothing algorithms should be used when forecasting VF results with PER or PLR. The application of smoothing algorithms on VF data can improve forecasting in VF points to assist in treatment decisions.

  14. A computer program for the pointwise functions generation

    International Nuclear Information System (INIS)

    Caldeira, Alexandre D.

    1995-01-01

    A computer program that was developed with the objective of generating pointwise functions, by a combination of tabulated values and/or mathematical expressions, to be used as weighting functions for nuclear data is presented. This simple program can be an important tool for researchers involved in group constants generation. (author). 5 refs, 2 figs

  15. Learning With Mixed Hard/Soft Pointwise Constraints.

    Science.gov (United States)

    Gnecco, Giorgio; Gori, Marco; Melacci, Stefano; Sanguineti, Marcello

    2015-09-01

    A learning paradigm is proposed and investigated, in which the classical framework of learning from examples is enhanced by the introduction of hard pointwise constraints, i.e., constraints imposed on a finite set of examples that cannot be violated. Such constraints arise, e.g., when requiring coherent decisions of classifiers acting on different views of the same pattern. The classical examples of supervised learning, which can be violated at the cost of some penalization (quantified by the choice of a suitable loss function) play the role of soft pointwise constraints. Constrained variational calculus is exploited to derive a representer theorem that provides a description of the functional structure of the optimal solution to the proposed learning paradigm. It is shown that such an optimal solution can be represented in terms of a set of support constraints, which generalize the concept of support vectors and open the doors to a novel learning paradigm, called support constraint machines. The general theory is applied to derive the representation of the optimal solution to the problem of learning from hard linear pointwise constraints combined with soft pointwise constraints induced by supervised examples. In some cases, closed-form optimal solutions are obtained.

  16. A Point-Wise Quantification of Asymmetry Using Deformation Fields

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Lanche, Stephanie; Darvann, Tron Andre

    2007-01-01

    of the resulting displacement vectors on the left and right side of the symmetry plane, gives a point-wise measure of asymmetry. The asymmetry measure was applied to the study of Crouzon syndrome using Micro CT scans of genetically modified mice. Crouzon syndrome is characterised by the premature fusion of cranial...

  17. Inbreeding, energy use and condition.

    Science.gov (United States)

    Ketola, T; Kotiaho, J S

    2009-04-01

    In energetic terms, fitness may be seen to be dependent on successful allocation of energy between life-history traits. In addition, fitness will be constrained by the energy allocation ability, which has also been defined as condition. We suggest here that the allocation ability, estimated as the difference between total energy budget and maintenance metabolism, may be used as a measure of condition. We studied this possibility by measuring the resting metabolic rate and metabolism during forced exercise in Gryllodes sigillatus crickets. To verify that these metabolic traits are closely related to fitness, we experimentally manipulated the degree of inbreeding of individuals belonging to the same pedigree, hence enabling analysis of both inbreeding depression and heritability of traits. We found that inbreeding increased maintenance metabolism, whereas total energy budget was rather insensitive to inbreeding. Despite this, inbreeding led to decreased allocation ability. Overall, metabolic traits exhibited strong inbreeding depression and rather low heritabilities, a pattern that is typical of traits under strong selection. However, traditionally used condition indices were not affected by inbreeding and did not covary with metabolic traits. Moreover, in contrast to the common, but largely untested, tenet, it seems that high resting metabolic rate is indicative of low rather than high quality.

  18. Regularity of pointwise boundary control systems

    DEFF Research Database (Denmark)

    Pedersen, Michael

    1992-01-01

    We will in these notes address some problems arising in "real-life" control application, namely problems concerning distributional control inputs on the boundary of the spatial domain. We extend the classical variational approach and give easily checkable sufficient conditions for the solutions...

  19. Pointwise Partial Information Decomposition Using the Specificity and Ambiguity Lattices

    Science.gov (United States)

    Finn, Conor; Lizier, Joseph

    2018-04-01

    What are the distinct ways in which a set of predictor variables can provide information about a target variable? When does a variable provide unique information, when do variables share redundant information, and when do variables combine synergistically to provide complementary information? The redundancy lattice from the partial information decomposition of Williams and Beer provided a promising glimpse at the answer to these questions. However, this structure was constructed using a much criticised measure of redundant information, and despite sustained research, no completely satisfactory replacement measure has been proposed. In this paper, we take a different approach, applying the axiomatic derivation of the redundancy lattice to a single realisation from a set of discrete variables. To overcome the difficulty associated with signed pointwise mutual information, we apply this decomposition separately to the unsigned entropic components of pointwise mutual information which we refer to as the specificity and ambiguity. This yields a separate redundancy lattice for each component. Then based upon an operational interpretation of redundancy, we define measures of redundant specificity and ambiguity enabling us to evaluate the partial information atoms in each lattice. These atoms can be recombined to yield the sought-after multivariate information decomposition. We apply this framework to canonical examples from the literature and discuss the results and the various properties of the decomposition. In particular, the pointwise decomposition using specificity and ambiguity satisfies a chain rule over target variables, which provides new insights into the so-called two-bit-copy example.

  20. Bare Quantum Null Energy Condition.

    Science.gov (United States)

    Fu, Zicao; Marolf, Donald

    2018-02-16

    The quantum null energy condition (QNEC) is a conjectured relation between a null version of quantum field theory energy and derivatives of quantum field theory von Neumann entropy. In some cases, divergences cancel between these two terms and the QNEC is intrinsically finite. We study the more general case here where they do not and argue that a QNEC can still hold for bare (unrenormalized) quantities. While the original QNEC applied only to locally stationary null congruences in backgrounds that solve semiclassical theories of quantum gravity, at least in the formal perturbation theory at a small Planck length, the quantum focusing conjecture can be viewed as the special case of our bare QNEC for which the metric is on shell.

  1. Averaged null energy condition and difference inequalities in quantum field theory

    International Nuclear Information System (INIS)

    Yurtsever, U.

    1995-01-01

    For a large class of quantum states, all local (pointwise) energy conditions widely used in relativity are violated by the renormalized stress-energy tensor of a quantum field. In contrast, certain nonlocal positivity constraints on the quantum stress-energy tensor might hold quite generally, and this possibility has received considerable attention in recent years. In particular, it is now known that the averaged null energy condition, the condition that the null-null component of the stress-energy tensor integrated along a complete null geodesic is non-negative for all states, holds quite generally in a wide class of spacetimes for a minimally coupled scalar field. Apart from the specific class of spacetimes considered (mainly two-dimensional spacetimes and four-dimensional Minkowski space), the most significant restriction on this result is that the null geodesic over which the average is taken must be achronal. Recently, Ford and Roman have explored this restriction in two-dimensional flat spacetime, and discovered that in a flat cylindrical space, although the stress energy tensor itself fails to satisfy the averaged null energy condition (ANEC) along the (nonachronal) null geodesics, when the ''Casimir-vacuum'' contribution is subtracted from the stress-energy the resulting tensor does satisfy the ANEC inequality. Ford and Roman name this class of constraints on the quantum stress-energy tensor ''difference inequalities.'' Here I give a proof of the difference inequality for a minimally coupled massless scalar field in an arbitrary (globally hyperbolic) two-dimensional spacetime, using the same techniques as those we relied on to prove the ANEC in an earlier paper with Wald. I begin with an overview of averaged energy conditions in quantum field theory

  2. Common Fixed Points for Asymptotic Pointwise Nonexpansive Mappings in Metric and Banach Spaces

    Directory of Open Access Journals (Sweden)

    P. Pasom

    2012-01-01

    Full Text Available Let C be a nonempty bounded closed convex subset of a complete CAT(0 space X. We prove that the common fixed point set of any commuting family of asymptotic pointwise nonexpansive mappings on C is nonempty closed and convex. We also show that, under some suitable conditions, the sequence {xk}k=1∞ defined by xk+1=(1-tmkxk⊕tmkTmnky(m-1k, y(m-1k=(1-t(m-1kxk⊕t(m-1kTm-1nky(m-2k,y(m-2k=(1-t(m-2kxk⊕t(m-2kTm-2nky(m-3k,…,y2k=(1-t2kxk⊕t2kT2nky1k,y1k=(1-t1kxk⊕t1kT1nky0k,y0k=xk,  k∈N, converges to a common fixed point of T1,T2,…,Tm where they are asymptotic pointwise nonexpansive mappings on C, {tik}k=1∞ are sequences in [0,1] for all i=1,2,…,m, and {nk} is an increasing sequence of natural numbers. The related results for uniformly convex Banach spaces are also included.

  3. Singularity theorems from weakened energy conditions

    International Nuclear Information System (INIS)

    Fewster, Christopher J; Galloway, Gregory J

    2011-01-01

    We establish analogues of the Hawking and Penrose singularity theorems based on (a) averaged energy conditions with exponential damping; (b) conditions on local stress-energy averages inspired by the quantum energy inequalities satisfied by a number of quantum field theories. As particular applications, we establish singularity theorems for the Einstein equations coupled to a classical scalar field, which violates the strong energy condition, and the nonminimally coupled scalar field, which also violates the null energy condition.

  4. OPTIMAL CONTROL OF A NONLINEAR COUPLED ELECTROMAGNETIC INDUCTION HEATING SYSTEM WITH POINTWISE STATE CONSTRAINTS

    Directory of Open Access Journals (Sweden)

    Irwin Yousept

    2010-07-01

    Full Text Available An optimal control problem arising in the context of 3D electromagnetic induction heating is investigated. The state equation is given by a quasilinear stationary heat equation coupled with a semilinear time harmonic eddy current equation. The temperature-dependent electrical conductivity and the presence of pointwise inequality state-constraints represent the main challenge of the paper. In the first part of the paper, the existence and regularity of the state are addressed. The second part of the paper deals with the analysis of the corresponding linearized equation. Some suffcient conditions are presented which guarantee thesolvability of the linearized system. The final part of the paper is concerned with the optimal control. The aim of the optimization is to find the optimal voltage such that a desired temperature can be achieved optimally. The corresponding first-order necessary optimality condition is presented.

  5. On Pointwise Approximation of Conjugate Functions by Some Hump Matrix Means of Conjugate Fourier Series

    Directory of Open Access Journals (Sweden)

    W. Łenski

    2015-01-01

    Full Text Available The results generalizing some theorems on N, pnE, γ summability are shown. The same degrees of pointwise approximation as in earlier papers by weaker assumptions on considered functions and examined summability methods are obtained. From presented pointwise results, the estimation on norm approximation is derived. Some special cases as corollaries are also formulated.

  6. Energy conditions and stability in general relativity

    International Nuclear Information System (INIS)

    Hall, G.S.

    1982-01-01

    The dominant energy condition in general relativity theory, which says that every observer measures a nonnegative local energy density and a nonspacelike local energy flow, is examined in connection with the types of energy-momentum tensor it permits. The condition that the energy-momentum tensor be ''stable'' in obeying the dominant energy conditions is then defined in terms of a suitable topology on the set of energy-momentum tensors on space-time and the consequences are evaluated and discussed. (author)

  7. Analysis of the stress field in a wedge using the fast expansions with pointwise determined coefficients

    Science.gov (United States)

    Chernyshov, A. D.; Goryainov, V. V.; Danshin, A. A.

    2018-03-01

    The stress problem for the elastic wedge-shaped cutter of finite dimensions with mixed boundary conditions is considered. The differential problem is reduced to the system of linear algebraic equations by applying twice the fast expansions with respect to the angular and radial coordinate. In order to determine the unknown coefficients of fast expansions, the pointwise method is utilized. The problem solution derived has explicit analytical form and it’s valid for the entire domain including its boundary. The computed profiles of the displacements and stresses in a cross-section of the cutter are provided. The stress field is investigated for various values of opening angle and cusp’s radius.

  8. Pointwise convergence and Ascoli theorems for nearness spaces

    Directory of Open Access Journals (Sweden)

    Zhanbo Yang

    2009-04-01

    Full Text Available We first study subspaces and product spaces in the context of nearness spaces and prove that U-N spaces, C-N spaces, PN spaces and totally bounded nearness spaces are nearness hereditary; T-N spaces and compact nearness spaces are N-closed hereditary. We prove that N2 plus compact implies N-closed subsets. We prove that totally bounded, compact and N2 are productive. We generalize the concepts of neighborhood systems into the nearness spaces and prove that the nearness neighborhood systems are consistent with existing concepts of neighborhood systems in topological spaces, uniform spaces and proximity spaces respectively when considered in the respective sub-categories. We prove that a net of functions is convergent under the pointwise convergent nearness structure if and only if its cross-section at each point is convergent. We have also proved two Ascoli-Arzelà type of theorems.

  9. A Pointwise Dimension Analysis of the Las Campanas Redshift Survey

    Science.gov (United States)

    Best, J. S.

    1999-12-01

    The modern motivation for fractal geometry may best be summed up by this quote of Benoit Mandelbrot: ``Mountains are not cones, clouds are not spheres, coastlines are not circles, and bark is not smooth, nor does lightning travel in a straight line.'' Fractals are, in simplest terms, ``objects which are (approximately) self-similar on all scales.'' The renewed modern interest in fractals has found as one of its applications the study of large-scale structure, giving a quantitative descriptive scheme to ideas that had been expressed qualitatively as early as the 1920s. This paper presents the preliminary results of an analysis of the structure of the Las Campanas Redshift Survey, or LCRS. LCRS is an approximately 26000 galaxy survey (surveyed as six declination slices) that has been studied extensively over the past few years, with an eye towards understanding large-scale structure. For this analysis, I have used the pointwise dimension, an easy-to-apply fractal statistic which has been previously used to study cluster interiors, galactic distributions, and cluster distributions. The present analysis has been performed to serve as a guide for the study of future large redshift surveys. This research has been funded by National Science Foundation grant AST-9808608.

  10. Market conditions affecting energy efficiency investments

    International Nuclear Information System (INIS)

    Seabright, J.

    1996-01-01

    The global energy efficiency market is growing, due in part to energy sector and macroeconomic reforms and increased awareness of the environmental benefits of energy efficiency. Many countries have promoted open, competitive markets, thereby stimulating economic growth. They have reduced or removed subsidies on energy prices, and governments have initiated energy conservation programs that have spurred the wider adoption of energy efficiency technologies. The market outlook for energy efficiency is quite positive. The global market for end-use energy efficiency in the industrial, residential and commercial sectors is now estimated to total more than $34 billion per year. There is still enormous technical potential to implement energy conservation measures and to upgrade to the best available technologies for new investments. For many technologies, energy-efficient designs now represent less than 10--20% of new product sales. Thus, creating favorable market conditions should be a priority. There are a number of actions that can be taken to create favorable market conditions for investing in energy efficiency. Fostering a market-oriented energy sector will lead to energy prices that reflect the true cost of supply. Policy initiatives should address known market failures and should support energy efficiency initiatives. And market transformation for energy efficiency products and services can be facilitated by creating an institutional and legal structure that favors commercially-oriented entities

  11. Stress-induced alterations of left-right electrodermal activity coupling indexed by pointwise transinformation

    Czech Academy of Sciences Publication Activity Database

    Světlák, M.; Bob, P.; Roman, R.; Ježek, S.; Damborská, A.; Chládek, Jan; Shaw, D. J.; Kukleta, M.

    2013-01-01

    Roč. 62, č. 6 (2013), s. 711-719 ISSN 0862-8408 Institutional support: RVO:68081731 Keywords : electrodermal activity * pointwise trasinformation * autonomic nervous system * asymmetry * stress Subject RIV: CE - Biochemistry Impact factor: 1.487, year: 2013

  12. Energy conditions bounds and supernovae data

    International Nuclear Information System (INIS)

    Lima, M.P.; Vitenti, S.D.P.; Reboucas, M.J.

    2008-01-01

    The energy conditions play an important role in the description of some important properties of the Universe, including the current accelerating expansion phase and the possible recent phase of super-acceleration. In a recent work we have provided a detailed study of the energy conditions for the recent past by deriving bounds from energy conditions and by making the confrontation of the bounds with supernovae data. Here, we extend and update these results in two different ways. First, by carrying out a new statistical analysis for q(z) estimates needed for the confrontation between the bounds and supernovae data. Second, by providing a new picture of the energy conditions fulfillment and violation in the light of the recently compiled Union set of 307 type Ia supernovae and by using two different statistical approaches

  13. ALTERNATE PURSUIT WITH THREE PARTICIPANTS (THE CASE OF POINTWISE MEETING

    Directory of Open Access Journals (Sweden)

    Viktor Shiryayev

    2016-03-01

    Full Text Available The issues connected with alternate pursuit of escapees group are considered in a number of papers. So in papers [1–3] the solution of the problem has been found in the assumption that the next meeting is selected at the initial time (by the program and the players are moving straight. In paper [4] the solution of the task using the approach of R. Isaacs is given. In paper [5] the choice opportunities of the next meeting ( both software and positional are considered. The article deals with a simple differential game on the pursuer plane P and the coalition of two escapees E={E1,E2}.The movement of all the players are assumed as inertialess. The pursuer speed P exceeds the speed of each of the escapees. The targets, physical abilities and the exact location of each other in any moment of the game are known to all players. The price of the coalition (the pursuer P is (minus the total time spent by the pursuer P on the pointwise meeting with E1 and E2. A coincidence of pursuer and escapee location is meant under the meeting. The choice at the initial time of the persecution is supposed as given (software selectable regular meeting. The limit of the security zone of the second escapee has been found. A geometric approach is used in the problem solving. The resulting system of equations is solved numerically by means of computer algebra, in particular through the Wolfram Mathematics. After defining the boundary of the second escapee security zone one can study the game between the pursuer Р and three escapees acting in concord (the first escapee is eliminated from the game.

  14. Giving up nuclear energy. Obstacles, conditions, consequences

    International Nuclear Information System (INIS)

    Koegel-Dorfs, H.

    1990-01-01

    Life on this earth is not possible without using energy. The resources of the energies used so far are limited and their utilization carries certain risks which have now become obvious: climatic problems on the one hand, safety problems on the other. Chernobyl, Wackersdorf, tornados and population growth are issues mentioned all the time in the fight for the best solution. Even church synodes have spoken up and demanded to give up nuclear energy. The energy issue, however, has become a question of survival. This study, worked out by a group of scientists (natural science, energy science, lawyers, theologians) analyses the obstacles, conditions and consequences of such a step. The possible solution of rational energy utilization and substitution of energy services and regenerative energies is discussed in depth. The book concludes that problems can only be coped with if there is a feeling of joint responsibility and global social consensus. (orig./HP) [de

  15. Instabilities and the null energy condition

    International Nuclear Information System (INIS)

    Buniy, Roman V.; Hsu, Stephen D.H.

    2006-01-01

    We show that violation of the null energy condition implies instability in a broad class of models, including gauge theories with scalar and fermionic matter as well as any perfect fluid. When applied to the dark energy, our results imply that w=p/ρ is unlikely to be less than -1. than -1

  16. Power conditioning system for energy sources

    Science.gov (United States)

    Mazumder, Sudip K [Chicago, IL; Burra, Rajni K [Chicago, IL; Acharya, Kaustuva [Chicago, IL

    2008-05-13

    Apparatus for conditioning power generated by an energy source includes an inverter for converting a DC input voltage from the energy source to a square wave AC output voltage, and a converter for converting the AC output voltage from the inverter to a sine wave AC output voltage.

  17. Stress-induced alterations of left-right electrodermal activity coupling indexed by pointwise transinformation.

    Science.gov (United States)

    Světlák, M; Bob, P; Roman, R; Ježek, S; Damborská, A; Chládek, J; Shaw, D J; Kukleta, M

    2013-01-01

    In this study, we tested the hypothesis that experimental stress induces a specific change of left-right electrodermal activity (EDA) coupling pattern, as indexed by pointwise transinformation (PTI). Further, we hypothesized that this change is associated with scores on psychometric measures of the chronic stress-related psychopathology. Ninety-nine university students underwent bilateral measurement of EDA during rest and stress-inducing Stroop test and completed a battery of self-report measures of chronic stress-related psychopathology. A significant decrease in the mean PTI value was the prevalent response to the stress conditions. No association between chronic stress and PTI was found. Raw scores of psychometric measures of stress-related psychopathology had no effect on either the resting levels of PTI or the amount of stress-induced PTI change. In summary, acute stress alters the level of coupling pattern of cortico-autonomic influences on the left and right sympathetic pathways to the palmar sweat glands. Different results obtained using the PTI, EDA laterality coefficient, and skin conductance level also show that the PTI algorithm represents a new analytical approach to EDA asymmetry description.

  18. Some considerations to the failure analysis of a pointwise attached steel liner membrane under constraint load

    International Nuclear Information System (INIS)

    Buchhardt, F.; Brandl, P.

    1981-01-01

    In the application of reinforced or prestressed concrete reactor containments, the safety enclosure will be obtained through a steel liner membrane, which is attached pointwise to the interior concrete surface. It is the objective and aim of this study to analyse the overall structural behaviour of the bonded system consisting of concrete containment, studs, and steel liner - especially under the aspect of extreme load and deformation conditions. The parametric analysis is carried out on the basis of the geometric length/depth ratio l/t = 12 of a single liner field. In order to reduce the considerable computational effort to a minimum, it is necessary to decouple the overall system in its structural components, i.e., at first an imperfect predeflected 'buckling' field and the residual 'plane' liner field are considered separately. A further reduction enables the use of stud anchor characteristics which are based on experiments. Three-dimensional analyses are performed for the single 'buckling' field to obtain specific load-displacement functions; the residual plane system is considered with two- as well as one-dimensional models. For the comprehensive parametric evalution of the overall system behaviour, a linear model is assumed to which these load-displacement functions are applied. Constraint temperatures are introduced as a unit scale - up to failure of the overall system; hereby partial structural failure might lead to temporary relief. (orig.)

  19. Wormholes, warp drives and energy conditions

    CERN Document Server

    2017-01-01

    Top researchers in the field of gravitation present the state-of-the-art topics outlined in this book, ranging from the stability of rotating wormholes solutions supported by ghost scalar fields, modified gravity applied to wormholes, the study of novel semi-classical and nonlinear energy conditions, to the applications of quantum effects and the superluminal version of the warp drive in modified spacetime. Based on Einstein's field equations, this cutting-edge research area explores the more far-fetched theoretical outcomes of General Relativity and relates them to quantum field theory. This includes quantum energy inequalities, flux energy conditions, and wormhole curvature, and sheds light on not just the theoretical physics but also on the possible applications to warp drives and time travel. This book extensively explores the physical properties and characteristics of these 'exotic spacetimes,' describing in detail the general relativistic geometries that generate closed timelike curves.

  20. Energy sector in conditions of market economy

    International Nuclear Information System (INIS)

    Schervashidze, N.

    1993-01-01

    The main dilemma of energy sector in market conditions is: regulation of the monopole producer and/or competition. There is no simple answer and the arguments for and against should be based on the macro economical determination of what kind of market is available for particular energy goods (perfect, monopolistic, oligopolistic, competition of monopolists) and what is the final purpose (improvement in efficiency, service, energy independence, regional development, etc.). Two polar models of economic management in energy sector are distinguished: 1) Free access to transfer net or competition between producers. 2) State regulation of the local monopolist. The experience of Great Britain and US are described as examples of both models. A special attention is paid to pricing methods at regulated monopole. 7 refs. (author)

  1. Energy principle with included boundary conditions

    International Nuclear Information System (INIS)

    Lehnert, B.

    1994-01-01

    Earlier comments by the author on the limitations of the classical form of the extended energy principle are supported by a complementary analysis on the potential energy change arising from free-boundary displacements of a magnetically confined plasma. In the final formulation of the extended principle, restricted displacements, satisfying pressure continuity by means of plasma volume currents in a thin boundary layer, are replaced by unrestricted (arbitrary) displacements which can give rise to induced surface currents. It is found that these currents contribute to the change in potential energy, and that their contribution is not taken into account by such a formulation. A general expression is further given for surface currents induced by arbitrary displacements. The expression is used to reformulate the energy principle for the class of displacements which satisfy all necessary boundary conditions, including that of the pressure balance. This makes a minimization procedure of the potential energy possible, for the class of all physically relevant test functions which include the constraints imposed by the boundary conditions. Such a procedure is also consistent with a corresponding variational calculus. (Author)

  2. Homoclinic chaos and energy condition violation

    International Nuclear Information System (INIS)

    Heinzle, J. Mark; Roehr, Niklas; Uggla, Claes

    2006-01-01

    In this letter we discuss the connection between so-called homoclinic chaos and the violation of energy conditions in locally rotationally symmetric Bianchi type IX models, where the matter is assumed to be nontilted dust and a positive cosmological constant. We show that homoclinic chaos in these models is an artifact of unphysical assumptions: it requires that there exist solutions with positive matter energy density ρ>0 that evolve through the singularity and beyond as solutions with negative matter energy density ρ<0. Homoclinic chaos is absent when it is assumed that the dust particles always retain their positive mass. In addition, we discuss more general models: for solutions that are not locally rotationally symmetric we demonstrate that the construction of extensions through the singularity, which is required for homoclinic chaos, is not possible in general

  3. Pointwise Multipliers on Spaces of Homogeneous Type in the Sense of Coifman and Weiss

    Directory of Open Access Journals (Sweden)

    Yanchang Han

    2014-01-01

    homogeneous type in the sense of Coifman and Weiss, pointwise multipliers of inhomogeneous Besov and Triebel-Lizorkin spaces are obtained. We make no additional assumptions on the quasi-metric or the doubling measure. Hence, the results of this paper extend earlier related results to a more general setting.

  4. Light energy dissipation under water stress conditions

    International Nuclear Information System (INIS)

    Stuhlfauth, T.; Scheuermann, R.; Fock, H.P.

    1990-01-01

    Using 14 CO 2 gas exchange and metabolite analyses, stomatal as well as total internal CO 2 uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to -2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO 2 exchange was drastically reduced, whereas the total CO 2 uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO 2 . This CO 2 -recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO 2 recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations

  5. Light energy dissipation under water stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Stuhlfauth, T.; Scheuermann, R.; Fock, H.P. (Universitaet Kaiserslautern (West Germany))

    1990-04-01

    Using {sup 14}CO{sub 2} gas exchange and metabolite analyses, stomatal as well as total internal CO{sub 2} uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to {minus}2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO{sub 2} exchange was drastically reduced, whereas the total CO{sub 2} uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO{sub 2}. This CO{sub 2}-recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO{sub 2} recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations.

  6. Wind energy under cold climate conditions

    Energy Technology Data Exchange (ETDEWEB)

    Maribo Pedersen, B.

    1999-03-01

    There is an increasing interest in wind energy production under different climatic conditions, among them cold climate and icing conditions. More and more wind turbines are being installed in cold climates and even adapted technology has been developed for that environment. Various national activities are going on in at least Finland, Canada, Italy, Sweden, etc. and international collaboration has been carried out within the European Union's Non-nuclear energy programme. Wind turbine operation is affected by both the cold temperatures and the formation of ice on the blades and the supporting structure. Cold temperatures can be handled by material selections known in other technical fields but to prevent icing, new techniques have to be - and have been - developed. Icing affects the reliability of anemometers, which concerns both turbine control and resource estimation, and changes the aerodynamics of the blades, which eventually stops the turbine. In addition, occasional icing events can locally affect public safety. The development of applied technology has entered some different paths and different solutions are tried out. As the applications are entering a commercial phase, these is a request to gather the experiences and monitor the reliability in a form that can be utilised by developers, manufactureres, consultants and other tenderers. The Topical Experts Meeting will focus on site classification, operational experiences, modelling and mesurements of ice induced loads and safety aspects. (EHS)

  7. Averaged null energy condition from causality

    Science.gov (United States)

    Hartman, Thomas; Kundu, Sandipan; Tajdini, Amirhossein

    2017-07-01

    Unitary, Lorentz-invariant quantum field theories in flat spacetime obey mi-crocausality: commutators vanish at spacelike separation. For interacting theories in more than two dimensions, we show that this implies that the averaged null energy, ∫ duT uu , must be non-negative. This non-local operator appears in the operator product expansion of local operators in the lightcone limit, and therefore contributes to n-point functions. We derive a sum rule that isolates this contribution and is manifestly positive. The argument also applies to certain higher spin operators other than the stress tensor, generating an infinite family of new constraints of the form ∫ duX uuu··· u ≥ 0. These lead to new inequalities for the coupling constants of spinning operators in conformal field theory, which include as special cases (but are generally stronger than) the existing constraints from the lightcone bootstrap, deep inelastic scattering, conformal collider methods, and relative entropy. We also comment on the relation to the recent derivation of the averaged null energy condition from relative entropy, and suggest a more general connection between causality and information-theoretic inequalities in QFT.

  8. 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.

  9. Pointwise asymptotic convergence of solutions for a phase separation model

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel; Zheng, S.

    2006-01-01

    Roč. 16, č. 1 (2006), s. 1-18 ISSN 1078-0947 Institutional research plan: CEZ:AV0Z10190503 Keywords : phase-field system * asymptotic phase separation * energy Subject RIV: BA - General Mathematics Impact factor: 1.087, year: 2006 http://aimsciences.org/journals/pdfs.jsp?paperID=1875&mode=full

  10. A remark on the energy conditions for Hawking's area theorem

    Science.gov (United States)

    Lesourd, Martin

    2018-06-01

    Hawking's area theorem is a fundamental result in black hole theory that is universally associated with the null energy condition. That this condition can be weakened is illustrated by the formulation of a strengthened version of the theorem based on an energy condition that allows for violations of the null energy condition. With the semi-classical context in mind, some brief remarks pertaining to the suitability of the area theorem and its energy condition are made.

  11. CSRL-V: processed ENDF/B-V 227-neutron-group and pointwise cross-section libraries for criticality safety, reactor, and shielding studies

    International Nuclear Information System (INIS)

    Ford, W.E. III; Diggs, B.R.; Petrie, L.M.; Webster, C.C.; Westfall, R.M.

    1982-01-01

    A P 3 227-neutron-group cross-section library has been processed for the subsequent generation of problem-dependent fine- or broad-group cross sections for a broad range of applications, including shipping cask calculations, general criticality safety analyses, and reactor core and shielding analyses. The energy group structure covers the range 10 -5 eV - 20 MeV, including 79 thermal groups below 3 eV. The 129-material library includes processed data for all materials in the ENDF/B-V General Purpose File, several data sets prepared from LENDL data, hydrogen with water- and polyethyelene-bound thermal kernels, deuterium with C 2 O-bound thermal kernels, carbon with a graphite thermal kernel, a special 1/V data set, and a dose factor data set. The library, which is in AMPX master format, is designated CSRL-V (Criticality Safety Reference Library based on ENDF/B-V data). Also included in CSRL-V is a pointwise total, fission, elastic scattering, and (n,γ) cross-section library containing data sets for all ENDF/B-V resonance materials. Data in the pointwise library were processed with the infinite dilute approximation at a temperature of 296 0 K

  12. arXiv Averaged Energy Conditions and Bouncing Universes

    CERN Document Server

    Giovannini, Massimo

    2017-11-16

    The dynamics of bouncing universes is characterized by violating certain coordinate-invariant restrictions on the total energy-momentum tensor, customarily referred to as energy conditions. Although there could be epochs in which the null energy condition is locally violated, it may perhaps be enforced in an averaged sense. Explicit examples of this possibility are investigated in different frameworks.

  13. Pointwise Stabilization of a Hybrid System and Optimal Location of Actuator

    International Nuclear Information System (INIS)

    Ammari, Kais; Saidi, Abdelkader

    2007-01-01

    We consider a pointwise stabilization problem for a model arising in the control of noise. We prove that we have exponential stability for the low frequencies but not for the high frequencies. Thus, we give an explicit polynomial decay estimation at high frequencies that is valid for regular initial data while clarifying that the behavior of the constant which intervenes in this estimation there, functions as the frequency of cut. We propose a numerical approximation of the model and study numerically the best location of the actuator at low frequencies

  14. Waste energy driven air conditioning system (WEDACS)

    NARCIS (Netherlands)

    Eichhorn, R.H.L.; Boot, M.D.; Luijten, C.C.M.

    2009-01-01

    In the port injected Spark Ignition (SI) engine, the single greatest part load efficiency reducing factor are energy losses over the throttle valve. The need for this throttle valve arises from the fact that engine power is controlled by the amount of air in the cylinders, since combustion occurs

  15. Broad frequency band full field measurements for advanced applications: Point-wise comparisons between optical technologies

    Science.gov (United States)

    Zanarini, Alessandro

    2018-01-01

    The progress of optical systems gives nowadays at disposal on lightweight structures complex dynamic measurements and modal tests, each with its own advantages, drawbacks and preferred usage domains. It is thus more easy than before to obtain highly spatially defined vibration patterns for many applications in vibration engineering, testing and general product development. The potential of three completely different technologies is here benchmarked on a common test rig and advanced applications. SLDV, dynamic ESPI and hi-speed DIC are here first deployed in a complex and unique test on the estimation of FRFs with high spatial accuracy from a thin vibrating plate. The latter exhibits a broad band dynamics and high modal density in the common frequency domain where the techniques can find an operative intersection. A peculiar point-wise comparison is here addressed by means of discrete geometry transforms to put all the three technologies on trial at each physical point of the surface. Full field measurement technologies cannot estimate only displacement fields on a refined grid, but can exploit the spatial consistency of the results through neighbouring locations by means of numerical differentiation operators in the spatial domain to obtain rotational degrees of freedom and superficial dynamic strain distributions, with enhanced quality, compared to other technologies in literature. Approaching the task with the aid of superior quality receptance maps from the three different full field gears, this work calculates and compares rotational and dynamic strain FRFs. Dynamic stress FRFs can be modelled directly from the latter, by means of a constitutive model, avoiding the costly and time-consuming steps of building and tuning a numerical dynamic model of a flexible component or a structure in real life conditions. Once dynamic stress FRFs are obtained, spectral fatigue approaches can try to predict the life of a component in many excitation conditions. Different

  16. The role of energy conditions in f(R) cosmology

    Science.gov (United States)

    Capozziello, S.; Nojiri, S.; Odintsov, S. D.

    2018-06-01

    Energy conditions can play an important role in defining the cosmological evolution. Specifically acceleration/deceleration of cosmic fluid, as well as the emergence of Big Rip singularities, can be related to the constraints imposed by the energy conditions. Here we discuss this issue for f (R) gravity considering also conformal transformations. Cosmological solutions and equations of state can be classified according to energy conditions. The qualitative change of some energy conditions when transformation from the Jordan frame to the Einstein frame done is also observed.

  17. Converting point-wise nuclear cross sections to pole representation using regularized vector fitting

    Science.gov (United States)

    Peng, Xingjie; Ducru, Pablo; Liu, Shichang; Forget, Benoit; Liang, Jingang; Smith, Kord

    2018-03-01

    Direct Doppler broadening of nuclear cross sections in Monte Carlo codes has been widely sought for coupled reactor simulations. One recent approach proposed analytical broadening using a pole representation of the commonly used resonance models and the introduction of a local windowing scheme to improve performance (Hwang, 1987; Forget et al., 2014; Josey et al., 2015, 2016). This pole representation has been achieved in the past by converting resonance parameters in the evaluation nuclear data library into poles and residues. However, cross sections of some isotopes are only provided as point-wise data in ENDF/B-VII.1 library. To convert these isotopes to pole representation, a recent approach has been proposed using the relaxed vector fitting (RVF) algorithm (Gustavsen and Semlyen, 1999; Gustavsen, 2006; Liu et al., 2018). This approach however needs to specify ahead of time the number of poles. This article addresses this issue by adding a poles and residues filtering step to the RVF procedure. This regularized VF (ReV-Fit) algorithm is shown to efficiently converge the poles close to the physical ones, eliminating most of the superfluous poles, and thus enabling the conversion of point-wise nuclear cross sections.

  18. Criticality benchmarks for COG: A new point-wise Monte Carlo code

    International Nuclear Information System (INIS)

    Alesso, H.P.; Pearson, J.; Choi, J.S.

    1989-01-01

    COG is a new point-wise Monte Carlo code being developed and tested at LLNL for the Cray computer. It solves the Boltzmann equation for the transport of neutrons, photons, and (in future versions) charged particles. Techniques included in the code for modifying the random walk of particles make COG most suitable for solving deep-penetration (shielding) problems. However, its point-wise cross-sections also make it effective for a wide variety of criticality problems. COG has some similarities to a number of other computer codes used in the shielding and criticality community. These include the Lawrence Livermore National Laboratory (LLNL) codes TART and ALICE, the Los Alamos National Laboratory code MCNP, the Oak Ridge National Laboratory codes 05R, 06R, KENO, and MORSE, the SACLAY code TRIPOLI, and the MAGI code SAM. Each code is a little different in its geometry input and its random-walk modification options. Validating COG consists in part of running benchmark calculations against critical experiments as well as other codes. The objective of this paper is to present calculational results of a variety of critical benchmark experiments using COG, and to present the resulting code bias. Numerous benchmark calculations have been completed for a wide variety of critical experiments which generally involve both simple and complex physical problems. The COG results, which they report in this paper, have been excellent

  19. Far offshore wind conditions in scope of wind energy

    NARCIS (Netherlands)

    Holtslag, M.C.

    2016-01-01

    Far offshore atmospheric conditions are favourable for wind energy purposes since mean wind speeds are relatively high (i.e., high power production) while turbulence levels are relatively low (i.e., less fatigue loads) compared to onshore conditions. Offshore wind energy, however, is still expensive

  20. Logarithmic corrections to gravitational entropy and the null energy condition

    Energy Technology Data Exchange (ETDEWEB)

    Parikh, Maulik, E-mail: maulik.parikh@asu.edu; Svesko, Andrew

    2016-10-10

    Using a relation between the thermodynamics of local horizons and the null energy condition, we consider the effects of quantum corrections to the gravitational entropy. In particular, we find that the geometric form of the null energy condition is not affected by the inclusion of logarithmic corrections to the Bekenstein–Hawking entropy.

  1. Logarithmic corrections to gravitational entropy and the null energy condition

    Directory of Open Access Journals (Sweden)

    Maulik Parikh

    2016-10-01

    Full Text Available Using a relation between the thermodynamics of local horizons and the null energy condition, we consider the effects of quantum corrections to the gravitational entropy. In particular, we find that the geometric form of the null energy condition is not affected by the inclusion of logarithmic corrections to the Bekenstein–Hawking entropy.

  2. Surface free energy for systems with integrable boundary conditions

    International Nuclear Information System (INIS)

    Goehmann, Frank; Bortz, Michael; Frahm, Holger

    2005-01-01

    The surface free energy is the difference between the free energies for a system with open boundary conditions and the same system with periodic boundary conditions. We use the quantum transfer matrix formalism to express the surface free energy in the thermodynamic limit of systems with integrable boundary conditions as a matrix element of certain projection operators. Specializing to the XXZ spin-1/2 chain we introduce a novel 'finite temperature boundary operator' which characterizes the thermodynamical properties of surfaces related to integrable boundary conditions

  3. Renewable energy market conditions and barriers in Turkey

    International Nuclear Information System (INIS)

    Nalan, Cicek Bezir; Murat, Oeztuerk; Nuri, Oezek

    2009-01-01

    Decentralized wind, hydropower, biogas and biomass, geothermal, solar thermal and solar electricity energy systems are the most commonly found renewable energy technologies promoted for rural energy supply within sustainable developments programs. They are, therefore, seen to have a central place in the practice of sustainable development and in allowing less development countries to bypass the environmentally damaging fossil fuel intensive paths made by industrialized countries. On the political front, many less development countries are critical of pressure on them to adopt environmental energy technologies. Turkey is situated the meeting point of three continents (Asia, Europe and Africa) and stands as a bridge between Asia and Europe. The country is located in southeastern Europe and southwestern Asia. As Turkey's economy has expanded in recent years, the consumption of primary energy has increased. Presently in order to increase the energy production from domestic energy resources, decrease the use of fossil fuels as well as reduce of green house gas emissions different renewable energy sources are used for energy production in Turkey. The share of energy production from renewable energy sources has increased during the last 10 years. Turkey must import most of the energy to meet her needs. Turkey also has a large potential for renewable energies. The lack of knowledge about renewable energy technologies by most policy-makers, potential consumers, and energy firm managers has played against renewable energy developments. The paper presents renewable energy used in Turkey and Europe Union and evaluation of the market conditions and barriers of renewable energy use in Turkey. (author)

  4. Energy conditions in f(G,T) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, M.; Ikram, Ayesha [University of the Punjab, Department of Mathematics, Lahore (Pakistan)

    2016-11-15

    The aim of this paper is to introduce a new modified gravity theory named f(G,T) gravity (G and T are the Gauss-Bonnet invariant and trace of the energy-momentum tensor, respectively) and investigate energy conditions for two reconstructed models in the context of FRW universe. We formulate general field equations, divergence of energy-momentum tensor, equation of motion for test particles as well as corresponding energy conditions. The massive test particles follow non-geodesic lines of geometry due to the presence of an extra force. We express the energy conditions in terms of cosmological parameters like the deceleration, jerk, and snap parameters. The reconstruction technique is applied to this theory using de Sitter and power-law cosmological solutions. We analyze the energy bounds and obtain feasible constraints on the free parameters. (orig.)

  5. Energy condition bounds and their confrontation with supernovae data

    International Nuclear Information System (INIS)

    Lima, M. P.; Vitenti, S.; Reboucas, M. J.

    2008-01-01

    The energy conditions play an important role in the understanding of several properties of the Universe, including the current accelerating expansion phase and the possible existence of the so-called phantom fields. We show that the integrated bounds provided by the energy conditions on cosmological observables such as the distance modulus μ(z) and the lookback time t L (z) are not sufficient (or necessary) to ensure the local fulfillment of the energy conditions, making explicit the limitation of these bounds in the confrontation with observational data. We recast the energy conditions as bounds on the deceleration and normalized Hubble parameters, obtaining new bounds which are necessary and sufficient for the local fulfillment of the energy conditions. A statistical confrontation, with 1σ-3σ confidence levels, between our bounds and supernovae data from the gold and combined samples is made for the recent past. Our analyses indicate, with 3σ confidence levels, the fulfillment of both the weak energy condition (WEC) and dominant energy condition (DEC) for z≤1 and z < or approx. 0.8, respectively. In addition, they suggest a possible recent violation of the null energy condition (NEC) with 3σ, i.e. a very recent phase of superacceleration. Our analyses also show the possibility of violation of the strong energy condition (SEC) with 3σ in the recent past (z≤1), but interestingly the q(z)-best-fit curve crosses the SEC--fulfillment divider at z≅0.67, which is a value very close to the beginning of the epoch of cosmic acceleration predicted by the standard concordance flat ΛCDM scenario.

  6. A fast pointwise strategy for anisotropic wave-mode separation in TI media

    KAUST Repository

    Liu, Qiancheng

    2017-08-17

    The multi-component wavefield contains both compressional and shear waves. Separating wave-modes has many applications in seismic workflows. Conventionally, anisotropic wave-mode separation is implemented by either directly filtering in the wavenumber domain or nonstationary filtering in the space domain, which are computationally expensive. These methods could be categorized into the pseudo-derivative family and only work well within Finite Difference (FD) methods. In this paper, we establish a relationship between group-velocity direction and polarity direction and propose a method, which could go beyond modeling by FD. In particular, we are interested in performing wave-mode separation in a Spectral Element Method (SEM), which is widely used for seismic wave propagation on various scales. The separation is implemented pointwise, independent of its neighbor points, suitable for running in parallel. Moreover, no correction for amplitude and phase changes caused by the derivative operator is required. We have verified our scheme using numerical examples.

  7. A fast pointwise strategy for anisotropic wave-mode separation in TI media

    KAUST Repository

    Liu, Qiancheng; Peter, Daniel; Lu, Yongming

    2017-01-01

    The multi-component wavefield contains both compressional and shear waves. Separating wave-modes has many applications in seismic workflows. Conventionally, anisotropic wave-mode separation is implemented by either directly filtering in the wavenumber domain or nonstationary filtering in the space domain, which are computationally expensive. These methods could be categorized into the pseudo-derivative family and only work well within Finite Difference (FD) methods. In this paper, we establish a relationship between group-velocity direction and polarity direction and propose a method, which could go beyond modeling by FD. In particular, we are interested in performing wave-mode separation in a Spectral Element Method (SEM), which is widely used for seismic wave propagation on various scales. The separation is implemented pointwise, independent of its neighbor points, suitable for running in parallel. Moreover, no correction for amplitude and phase changes caused by the derivative operator is required. We have verified our scheme using numerical examples.

  8. Summary - COG: A new point-wise Monte Carlo code for burnup credit analysis

    International Nuclear Information System (INIS)

    Alesso, H.P.

    1989-01-01

    COG, a new point-wise Monte Carlo code being developed and tested at Lawrence Livermore National Laboratory (LLNL) for the Cray-1, solves the Boltzmann equation for the transport of neutrons, photons, and (in future versions) other particles. Techniques included in the code for modifying the random walk of particles make COG most suitable for solving deep-penetration (shielding) problems and a wide variety of criticality problems. COG is similar to a number of other computer codes used in the shielding community. Each code is a little different in its geometry input and its random-walk modification options. COG is a Monte Carlo code specifically designed for the CRAY (in 1986) to be as precise as the current state of physics knowledge. It has been extensively benchmarked and used as a shielding code at LLNL since 1986, and has recently been extended to accomplish criticality calculations. It will make an excellent tool for future shipping cask studies

  9. Measuring global oil trade dependencies: An application of the point-wise mutual information method

    International Nuclear Information System (INIS)

    Kharrazi, Ali; Fath, Brian D.

    2016-01-01

    Oil trade is one of the most vital networks in the global economy. In this paper, we analyze the 1998–2012 oil trade networks using the point-wise mutual information (PMI) method and determine the pairwise trade preferences and dependencies. Using examples of the USA's trade partners, this research demonstrates the usefulness of the PMI method as an additional methodological tool to evaluate the outcomes from countries' decisions to engage in preferred trading partners. A positive PMI value indicates trade preference where trade is larger than would be expected. For example, in 2012 the USA imported 2,548.7 kbpd despite an expected 358.5 kbpd of oil from Canada. Conversely, a negative PMI value indicates trade dis-preference where the amount of trade is smaller than what would be expected. For example, the 15-year average of annual PMI between Saudi Arabia and the U.S.A. is −0.130 and between Russia and the USA −1.596. We reflect the three primary reasons of discrepancies between actual and neutral model trade can be related to position, price, and politics. The PMI can quantify the political success or failure of trade preferences and can more accurately account temporal variation of interdependencies. - Highlights: • We analyzed global oil trade networks using the point-wise mutual information method. • We identified position, price, & politics as drivers of oil trade preference. • The PMI method is useful in research on complex trade networks and dependency theory. • A time-series analysis of PMI can track dependencies & evaluate policy decisions.

  10. Utilization of Solar Energy for Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Sutikno Juwari Purwo

    2018-01-01

    Full Text Available The purposes of this research are to do a system simulation of air conditioning utilizing solar energy with single effect absorption refrigeration method, analyze the coefficient of performance (COP for each absorbent-refrigerant variable and compare the effectivity of every absorbent-refrigerant variable used. COP is a constant that denotes the effeciency of a refrigeration system, that is ratio of work or useful output to the amount of work or energy input. The higher the number of COP, the more efficient the system is. Absorbent-refrigerant (working fluids variables used in this research depend on its chemical and thermodynamics properties. Steps in this research are including data collection and tabulation from literature and do a simulation of air conditioning system both commercial air conditioning system (using electrical energy and solar energy air conditioning system with Aspen Plus software. Next, run the simulation for each working fluid variables used and calculate the COP for each variable. Subsequently, analyze and compare the effectivity of all variables used from COP value and economical point of view with commercial air conditioning system. From the result of the simulation, can be concluded that solar air conditioning can achieve 98,85 % of energy savings than commercial air conditioning. Furthermore, from the calculation of COP, the highest COP value is achieved by solar conditioning system with LiNO3-NH3 as working fluid where 55% of the composition is the refrigerant and 45% of absorbent.

  11. Superlattice band structure: New and simple energy quantification condition

    Energy Technology Data Exchange (ETDEWEB)

    Maiz, F., E-mail: fethimaiz@gmail.com [University of Cartage, Nabeul Engineering Preparatory Institute, Merazka, 8000 Nabeul (Tunisia); King Khalid University, Faculty of Science, Physics Department, P.O. Box 9004, Abha 61413 (Saudi Arabia)

    2014-10-01

    Assuming an approximated effective mass and using Bastard's boundary conditions, a simple method is used to calculate the subband structure for periodic semiconducting heterostructures. Our method consists to derive and solve the energy quantification condition (EQC), this is a simple real equation, composed of trigonometric and hyperbolic functions, and does not need any programming effort or sophistic machine to solve it. For less than ten wells heterostructures, we have derived and simplified the energy quantification conditions. The subband is build point by point; each point presents an energy level. Our simple energy quantification condition is used to calculate the subband structure of the GaAs/Ga{sub 0.5}Al{sub 0.5}As heterostructures, and build its subband point by point for 4 and 20 wells. Our finding shows a good agreement with previously published results.

  12. RENEWABLE ENERGY SOURCES IN POLAND - CONDITIONS AND POSSIBILITES OF DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, L.; Mokrzycki, E.; Ney, R.

    2007-07-01

    The paper describes the state of the art in renewable energy sources development. The obligation resulting from the membership of Poland in the European Union as well as from other international agreements in the scope of renewable energy sources development are described. The production of electricity, heat and biofuels in Poland is given and the perspectives of development of particular renewable energy sources in Poland are discussed in the view of potential reserves and other constrains. The economic aspects of renewable energy technologies are shown. The environmental pros and cons of biomass energy development are described. Arguments for development of renewable energy sources use are stated: the decrease of dependence from primary energy sources, the decrease the emission of green house gases and the recovery of agricultural regions of the country. In conclusion it is stated that the significance of renewable energy sources in Polish conditions is constrained to local societies. Their development should be adjusted to conditions predominating in a given region and that wider consumption of renewable energy sources should develop in conformity with sustainable development, so it is necessary to reach agreement between local societies, institutions dealing with environment protection and representatives of power sector. (auth)

  13. Municipal Energy Planning under Conditions of Globalization: Imperatives and Objectives

    Directory of Open Access Journals (Sweden)

    Horban Vasylyna B.

    2017-12-01

    Full Text Available The article reveals the importance of energy planning for local authorities in the path of achieving the goals of sustainable development. The quintessence of energy planning in territorial communities of Ukraine and Europe has been outlined from the perspective of analyzing the infrastructure sectors of the municipal economy. The article is based on observing certain international methodologies related to local energy and climate planning. The evolution of Covenant of Mayors initiative is briefly described with a focus on its intensive expanding in terms of energy and climate issues. The experience in the development of municipal sustainable energy and climate action plans in European countries and Ukraine is studied. A survey of empirical data on the consumption of fuel and energy resources and greenhouse gas emissions in territorial communities of Ukraine and European countries is conducted. The European methodological guidelines on the subject under study are highlighted based on the key policy documents. A few practical examples of Ukrainian and European cities are presented in order to illustrate possible actions corresponding to the defined problem. A systematic framework is proposed to describe the various and complex aspects of energy planning in cities with regard to rational implementation of energy efficient measures. The innovative mechanisms, main barriers and opportunities for the effective implementation of energy efficient projects in territorial communities of Ukraine and European countries are revealed. It is substantiated that under the current conditions of globalization, using project-oriented paradigm, municipal energy planning instruments become key motivational factors for development sustainable energy policy.

  14. Cosmological viability conditions for f(T) dark energy models

    Energy Technology Data Exchange (ETDEWEB)

    Setare, M.R.; Mohammadipour, N., E-mail: rezakord@ipm.ir, E-mail: N.Mohammadipour@uok.ac.ir [Department of Science, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2012-11-01

    Recently f(T) modified teleparallel gravity where T is the torsion scalar has been proposed as the natural gravitational alternative for dark energy. We perform a detailed dynamical analysis of these models and find conditions for the cosmological viability of f(T) dark energy models as geometrical constraints on the derivatives of these models. We show that in the phase space exists two cosmologically viable trajectory which (i) The universe would start from an unstable radiation point, then pass a saddle standard matter point which is followed by accelerated expansion de sitter point. (ii) The universe starts from a saddle radiation epoch, then falls onto the stable matter era and the system can not evolve to the dark energy dominated epoch. Finally, for a number of f(T) dark energy models were proposed in the more literature, the viability conditions are investigated.

  15. Condition of nuclear energy policy development in Ukraine

    International Nuclear Information System (INIS)

    Hudyma, A.; Piriashvili, B.; Khakimov, Y.; Khrushtchov, D.

    2000-01-01

    The preservation and strengthening of economic and political stability of the state depends first of all on the situation in the main branches of economy. One of such branches is the energy sector, whose level of development defines the place and the role of the state in the world community. On the other hand, the status of the energy sector, one of the major elements ensuring political and economic stability, determines energy security as well. Besides, the concept of energy sector development in general and nuclear energy in particular should be based on the real geopolitical situation, which Ukraine has faced after USSR disintegration. Therefore, the energy policy development is the most important link in the development of the state itself, for importance of this policy goes far beyond the frameworks of the energy sector. Besides, it is necessary to note, that the new geopolitical conditions have abruptly changed the course of economic and social development of the country. Frist of all, it was reflected in the significant drop of its energy security that resulted in: first sharp fall own fuel resources production and electric power generation; second significant reduction in inflow of energy resources to Ukraine. Such situation is stipulated by the general drop in the demand for power resources due to general fall in industrial and agricultural production, as well as by the sharp decrease in own energy resources production and absence of sufficient financial means for the acquisition of the deficient power resources import

  16. Effect of different glucose supply conditions on neuronal energy metabolism

    OpenAIRE

    Zheng, Hongwen; Wang, Rubin; Qu, Jingyi

    2016-01-01

    The glucose-excited neurons in brain can sense blood glucose levels and reflect different firing states, which are mainly associated with regulation of blood glucose and energy demand in the brain. In this paper, a new model of glucose-excited neuron in hypothalamus is proposed. The firing properties and energy consumption of this type of neuron under conditions of different glucose levels are simulated and analyzed. The results show that the firing rate and firing duration of the neuron both...

  17. Energy Saving Potential by Utilizing Natural Ventilation under Warm Conditions

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2014-01-01

    The objective of this article is to show the potential of natural ventilation as a passive cooling method within the residential sector of countries which are located in warm conditions using Mexico as a case study. The method is proposed as performing, with a simplified ventilation model, thermal......–airflow simulations of 27 common cases of dwellings (considered as one thermal zone) based on the combination of specific features of the building design, occupancy and climate conditions. The energy saving potential is assessed then by the use of a new assessment method suitable for large-scale scenarios using...... the actual number of air-conditioned dwellings distributed among the 27 cases. Thereby, the energy saving is presented as the difference in the cooling demand of the dwelling during one year without and with natural ventilation, respectively. Results indicate that for hot-dry conditions, buildings with high...

  18. Application of solar energy to air conditioning systems

    Science.gov (United States)

    Nash, J. M.; Harstad, A. J.

    1976-01-01

    The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature.

  19. Impact of external conditions on energy consumption in industrial halls

    Science.gov (United States)

    Żabnieńśka-Góra, Alina

    2017-11-01

    The energy demand for heating the halls buildings is high. The impact on this may have the technology of production, building construction and technology requirements (HVAC systems). The isolation of the external partitions, the location of the object in relation to the surrounding buildings and the degree of the interior insolation (windows and skylights) are important in the context of energy consumption. The article discusses the impact of external conditions, wind and sunlight on energy demand in the industrial hall. The building model was prepared in IDA ICE 4.0 simulation software. Model validation was done based on measurements taken in the analyzed building.

  20. Backtest type and housing condition of pigs influence energy metabolism

    NARCIS (Netherlands)

    Geverink, N.A.; Heetkamp, M.J.W.; Schouten, W.G.P.; Wiegant, V.M.; Schrama, J.W.

    2004-01-01

    The behavioral response of piglets in a backtest early in life seems indicative of their coping strategy at a later age. Coping characteristics may depend on the interaction between backtest classification and housing conditions. We studied whether growth rate and partitioning of energy in adult

  1. Energy Strategy of Russia in the Conditions of Economic Crisis

    Directory of Open Access Journals (Sweden)

    Kashulin Danila A.

    2016-10-01

    Full Text Available The article is devoted to the transformation of the energy strategy of Russia in the conditions of the current economic crisis. The special attention is paid to current trends in the sphere of international relations having a decisive influence on the formation of Russia’s energy strategy. The authors point to the crisis of the modern world, the deepening of interstate contradictions, the expansion of confrontation, the revision of the uniform principles of trade, established by the World Trade Organization, the changes in the global financial system. The authors investigate the possibility of political arrangements between the leading suppliers of oil on the destabilization of the oil market in order to achieve geopolitical goals. In the article special attention is also paid to the issue of political motivation of anti-Russian sanctions directed at impeding Russia’s development and its Fuel & Energy Complex, in particular. Today, against the background of the current political situation, the energy strategy of Russia is exposed to adjustment. The country has the important task of ensuring technological independence of the energy sector on the basis of import substitution of the equipment, diversification of the directions of export of energy resources, preservation of leading positions in the world market of peaceful nuclear energy, etc. The authors conclude that the energy strategy of Russia is important part of foreign policy strategy of the country, and it is focused on practical cooperation with all countries and is aimed at protecting interests of the state.

  2. Wind, Wave, and Tidal Energy Without Power Conditioning

    Science.gov (United States)

    Jones, Jack A.

    2013-01-01

    Most present wind, wave, and tidal energy systems require expensive power conditioning systems that reduce overall efficiency. This new design eliminates power conditioning all, or nearly all, of the time. Wind, wave, and tidal energy systems can transmit their energy to pumps that send high-pressure fluid to a central power production area. The central power production area can consist of a series of hydraulic generators. The hydraulic generators can be variable displacement generators such that the RPM, and thus the voltage, remains constant, eliminating the need for further power conditioning. A series of wind blades is attached to a series of radial piston pumps, which pump fluid to a series of axial piston motors attached to generators. As the wind is reduced, the amount of energy is reduced, and the number of active hydraulic generators can be reduced to maintain a nearly constant RPM. If the axial piston motors have variable displacement, an exact RPM can be maintained for all, or nearly all, wind speeds. Analyses have been performed that show over 20% performance improvements with this technique over conventional wind turbines

  3. Praxeological analysis of the teaching conditions of the energy concept

    Directory of Open Access Journals (Sweden)

    Mehmet Altan Kurnaz

    2010-12-01

    Full Text Available Since there is disagreement with regard to a single definition of energy in the literature, knowing how a discipline introducesenergy, because of the direct effects of teaching conditions on students’ learning, maintains its importance. From this point ofview, the objective of this research is to determine the teaching conditions with regard to energy of a discipline in a universityin Turkey. In order to achieve this, an institutional analysis was conducted based on the Praxeological Approach. Severalimportant results were obtained from the study such as the fact that the teaching of energy processes at the year 1 level in aTurkish University is performed from a restricted perspective, using an operational approach. The results of this studyemphasize the need for an interdisciplinary approach and multiple representations, including conceptual activities as a meansof introducing energy concepts. As a general recommendation, it is also recommended that the analysis of the interactionbetween teaching and learning conditions may be useful for the development of a new approach with regard to energyconcepts.

  4. Performance of desiccant air conditioning system with geothermal energy under different climatic conditions

    International Nuclear Information System (INIS)

    El-Agouz, S.A.; Kabeel, A.E.

    2014-01-01

    Highlights: • The performance of the hybrid air conditioning system is studied. • The influence of important operating parameters are estimated. • The ventilation, makeup and mix cycles are investigated at different climate. • The highest COP of the hybrid air conditioning system is 1.03. • The hybrid system provides a human thermal comfort at different climates. - Abstract: Energy saving still and continue a major seek in our life, due to the continuous increase in energy consumptions. So, a desiccant air conditioning system with geothermal energy is conducted in the current study. The thermal analysis of air conditioning system with its different components desiccant wheel, solar collector, heat exchanger, ground heat exchanger and water spray evaporative cooler is presented. Three different air conditioning cycles are simulated in the current study for different zones like: hot-dry zone, warm-dry zone, hot-humid zone and the warm-humid zone. The results show that the desiccant air conditioning system successfully provides a better thermal comfort condition in different climates. This hybrid system significantly decreases the supplied air temperature from 12.7 to 21.7 °C at different climate zones. When ω in , air and T Reg increasing, COP decreases and the ventilation cycle provides the better COP. The highest COP value of the desiccant air conditioning system is about 1.03 while the lowest value is about 0.15. The SHR of makeup cycle is higher than that ventilation cycle at warm and hot-humid zone and vice versa at warm and hot-dry zone. The highest SHR value of the desiccant air conditioning system is about 0.99 while the lowest value is about 0.2. The T sup,air , ω sup,air , COP and SHR isolines may easily be used for pre-evaluating of various cooling cycles in different climates. The hybrid system provides a human thermal comfort at different climates

  5. Pointwise mutual information quantifies intratumor heterogeneity in tissue sections labeled with multiple fluorescent biomarkers

    Directory of Open Access Journals (Sweden)

    Daniel M Spagnolo

    2016-01-01

    Full Text Available Background: Measures of spatial intratumor heterogeneity are potentially important diagnostic biomarkers for cancer progression, proliferation, and response to therapy. Spatial relationships among cells including cancer and stromal cells in the tumor microenvironment (TME are key contributors to heterogeneity. Methods: We demonstrate how to quantify spatial heterogeneity from immunofluorescence pathology samples, using a set of 3 basic breast cancer biomarkers as a test case. We learn a set of dominant biomarker intensity patterns and map the spatial distribution of the biomarker patterns with a network. We then describe the pairwise association statistics for each pattern within the network using pointwise mutual information (PMI and visually represent heterogeneity with a two-dimensional map. Results: We found a salient set of 8 biomarker patterns to describe cellular phenotypes from a tissue microarray cohort containing 4 different breast cancer subtypes. After computing PMI for each pair of biomarker patterns in each patient and tumor replicate, we visualize the interactions that contribute to the resulting association statistics. Then, we demonstrate the potential for using PMI as a diagnostic biomarker, by comparing PMI maps and heterogeneity scores from patients across the 4 different cancer subtypes. Estrogen receptor positive invasive lobular carcinoma patient, AL13-6, exhibited the highest heterogeneity score among those tested, while estrogen receptor negative invasive ductal carcinoma patient, AL13-14, exhibited the lowest heterogeneity score. Conclusions: This paper presents an approach for describing intratumor heterogeneity, in a quantitative fashion (via PMI, which departs from the purely qualitative approaches currently used in the clinic. PMI is generalizable to highly multiplexed/hyperplexed immunofluorescence images, as well as spatial data from complementary in situ methods including FISSEQ and CyTOF, sampling many different

  6. Alternative air-conditioning with the use of solar energy

    International Nuclear Information System (INIS)

    Algarbi, N. M.

    2006-01-01

    The paper concerns the investigation of the alternative air condition systems on the basis of the open absorbtion cycle with the use of solar energy as a heat source. Schematic solution of systems has been carried. The design analysis of working characteristics was performed for a wide rang of initial parameters (teperature and humidity of ambient air, the type and concentration of liquid sorbents, etc.) and construction features of heat and mass transfer.(Author)

  7. Workshop on power conditioning for alternative energy technologies. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D. R.

    1979-01-01

    As various alternative energy technologies such as photovoltaics, wind, fuel cells, and batteries are emerging as potential sources of energy for the future, the need arises for development of suitable power-conditioning systems to interface these sources to their respective loads. Since most of these sources produce dc electricity and most electrical loads require ac, an important component of the required power-conditioning units is a dc-to-ac inverter. The discussions deal with the development of power conditioners for each alternative energy technology. Discussion topics include assessments of current technology, identification of operational requirements with a comparison of requirements for each source technology, the identification of future technology trends, the determination of mass production and marketing requirements, and recommendations for program direction. Specifically, one working group dealt with source technology: photovoltaics, fuel cells and batteries, and wind followed by sessions discussing system size and application: large grid-connected systems, small grid-connected systems, and stand alone and dc applications. A combined group session provided an opportunity to discuss problems common to power conditioning development.

  8. Plate with a hole obeys the averaged null energy condition

    International Nuclear Information System (INIS)

    Graham, Noah; Olum, Ken D.

    2005-01-01

    The negative energy density of Casimir systems appears to violate general relativity energy conditions. However, one cannot test the averaged null energy condition (ANEC) using standard calculations for perfectly reflecting plates, because the null geodesic would have to pass through the plates, where the calculation breaks down. To avoid this problem, we compute the contribution to ANEC for a geodesic that passes through a hole in a single plate. We consider both Dirichlet and Neumann boundary conditions in two and three space dimensions. We use a Babinet's principle argument to reduce the problem to a complementary finite disk correction to the perfect mirror result, which we then compute using scattering theory in elliptical and spheroidal coordinates. In the Dirichlet case, we find that the positive correction due to the hole overwhelms the negative contribution of the infinite plate. In the Neumann case, where the infinite plate gives a positive contribution, the hole contribution is smaller in magnitude, so again ANEC is obeyed. These results can be extended to the case of two plates in the limits of large and small hole radii. This system thus provides another example of a situation where ANEC turns out to be obeyed when one might expect it to be violated

  9. The quantum null energy condition in curved space

    Science.gov (United States)

    Fu, Zicao; Koeller, Jason; Marolf, Donald

    2017-11-01

    The quantum null energy condition (QNEC) is a conjectured bound on components (Tkk = Tab ka k^b) of the stress tensor along a null vector k a at a point p in terms of a second k-derivative of the von Neumann entropy S on one side of a null congruence N through p generated by k a . The conjecture has been established for super-renormalizeable field theories at points p that lie on a bifurcate Killing horizon with null tangent k a and for large-N holographic theories on flat space. While the Koeller-Leichenauer holographic argument clearly yields an inequality for general ( p, k^a) , more conditions are generally required for this inequality to be a useful QNEC. For d≤slant 3 , for arbitrary backgroud metric we show that the QNEC is naturally finite and independent of renormalization scheme when the expansion θ of N at the point p vanishes. This is consistent with the original QNEC conjecture which required θ and the shear σab to satisfy θ \\vert _p= \\dotθ\\vert p =0 , σab\\vert _p=0 . But for d=4, 5 more conditions than even these are required. In particular, we also require the vanishing of additional derivatives and a dominant energy condition. In the above cases the holographic argument does indeed yield a finite QNEC, though for d≥slant6 we argue these properties to fail even for weakly isolated horizons (where all derivatives of θ, σab vanish) that also satisfy a dominant energy condition. On the positive side, a corrollary to our work is that, when coupled to Einstein-Hilbert gravity, d ≤slant 3 holographic theories at large N satisfy the generalized second law (GSL) of thermodynamics at leading order in Newton’s constant G. This is the first GSL proof which does not require the quantum fields to be perturbations to a Killing horizon.

  10. Energy Analysis for Air Conditioning System Using Fuzzy Logic Control

    Directory of Open Access Journals (Sweden)

    Henry Nasution

    2011-04-01

    Full Text Available Reducing energy consumption and to ensure thermal comfort are two important considerations for the designing an air conditioning system. An alternative approach to reduce energy consumption proposed in this study is to use a variable speed compressor. The control strategy will be proposed using the fuzzy logic controller (FLC. FLC was developed to imitate the performance of human expert operators by encoding their knowledge in the form of linguistic rules. The system is installed on a thermal environmental room with a data acquisition system to monitor the temperature of the room, coefficient of performance (COP, energy consumption and energy saving. The measurements taken during the two hour experimental periods at 5-minutes interval times for temperature setpoints of 20oC, 22oC and 24oC with internal heat loads 0, 500, 700 and 1000 W. The experimental results indicate that the proposed technique can save energy in comparison with On/Off and proportional-integral-derivative (PID control.

  11. Energy conditions in modified Gauss-Bonnet gravity

    International Nuclear Information System (INIS)

    Garcia, Nadiezhda Montelongo; Harko, Tiberiu; Lobo, Francisco S. N.; Mimoso, Jose P.

    2011-01-01

    In considering alternative higher-order gravity theories, one is liable to be motivated in pursuing models consistent and inspired by several candidates of a fundamental theory of quantum gravity. Indeed, motivations from string/M theory predict that scalar field couplings with the Gauss-Bonnet invariant, G, are important in the appearance of nonsingular early time cosmologies. In this work, we discuss the viability of an interesting alternative gravitational theory, namely, modified Gauss-Bonnet gravity or f(G) gravity. We consider specific realistic forms of f(G) analyzed in the literature that account for the late-time cosmic acceleration and that have been found to cure the finite-time future singularities present in the dark energy models. We present the general inequalities imposed by the energy conditions and use the recent estimated values of the Hubble, deceleration, jerk and snap parameters to examine the viability of the above-mentioned forms of f(G) imposed by the weak energy condition.

  12. The Existing Regulatory Conditions for 'Energy Smart Water Utilities'

    DEFF Research Database (Denmark)

    Basse, Ellen Margrethe

    2014-01-01

    This chapter is focused on the legal conditions that exist for the energy–smart water utilities in the European Union (EU). In section 2 the interdependencies of water and energy services and the growing interest in solving these problems that may arise from this interdependence by regulatory ini...... legal design and the problems that it causes for the water utilities that want to be resource–efficient and have a low–carbon footprint.......This chapter is focused on the legal conditions that exist for the energy–smart water utilities in the European Union (EU). In section 2 the interdependencies of water and energy services and the growing interest in solving these problems that may arise from this interdependence by regulatory...... initiatives are shortly described. One of the solutions needed is a reduction of energy use in the water utilities by their utilisation of renewable sources – acting as energy–smart water utilities. Such utilities are described in section 3. The policy and law regulating the water utilities are important...

  13. Sensing Slow Mobility and Interesting Locations for Lombardy Region (italy): a Case Study Using Pointwise Geolocated Open Data

    Science.gov (United States)

    Brovelli, M. A.; Oxoli, D.; Zurbarán, M. A.

    2016-06-01

    During the past years Web 2.0 technologies have caused the emergence of platforms where users can share data related to their activities which in some cases are then publicly released with open licenses. Popular categories for this include community platforms where users can upload GPS tracks collected during slow travel activities (e.g. hiking, biking and horse riding) and platforms where users share their geolocated photos. However, due to the high heterogeneity of the information available on the Web, the sole use of these user-generated contents makes it an ambitious challenge to understand slow mobility flows as well as to detect the most visited locations in a region. Exploiting the available data on community sharing websites allows to collect near real-time open data streams and enables rigorous spatial-temporal analysis. This work presents an approach for collecting, unifying and analysing pointwise geolocated open data available from different sources with the aim of identifying the main locations and destinations of slow mobility activities. For this purpose, we collected pointwise open data from the Wikiloc platform, Twitter, Flickr and Foursquare. The analysis was confined to the data uploaded in Lombardy Region (Northern Italy) - corresponding to millions of pointwise data. Collected data was processed through the use of Free and Open Source Software (FOSS) in order to organize them into a suitable database. This allowed to run statistical analyses on data distribution in both time and space by enabling the detection of users' slow mobility preferences as well as places of interest at a regional scale.

  14. SENSING SLOW MOBILITY AND INTERESTING LOCATIONS FOR LOMBARDY REGION (ITALY: A CASE STUDY USING POINTWISE GEOLOCATED OPEN DATA

    Directory of Open Access Journals (Sweden)

    M. A. Brovelli

    2016-06-01

    Full Text Available During the past years Web 2.0 technologies have caused the emergence of platforms where users can share data related to their activities which in some cases are then publicly released with open licenses. Popular categories for this include community platforms where users can upload GPS tracks collected during slow travel activities (e.g. hiking, biking and horse riding and platforms where users share their geolocated photos. However, due to the high heterogeneity of the information available on the Web, the sole use of these user-generated contents makes it an ambitious challenge to understand slow mobility flows as well as to detect the most visited locations in a region. Exploiting the available data on community sharing websites allows to collect near real-time open data streams and enables rigorous spatial-temporal analysis. This work presents an approach for collecting, unifying and analysing pointwise geolocated open data available from different sources with the aim of identifying the main locations and destinations of slow mobility activities. For this purpose, we collected pointwise open data from the Wikiloc platform, Twitter, Flickr and Foursquare. The analysis was confined to the data uploaded in Lombardy Region (Northern Italy – corresponding to millions of pointwise data. Collected data was processed through the use of Free and Open Source Software (FOSS in order to organize them into a suitable database. This allowed to run statistical analyses on data distribution in both time and space by enabling the detection of users’ slow mobility preferences as well as places of interest at a regional scale.

  15. Exergy storage to exploit solar energy in air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Navarrete-Gonzalez, J.J.; Torres-Reyes, E. [Guanajuato Univ., Guanajuato (Mexico). Inst. de Investigaciones Cientificas; Cervantes-de Gortari, J.G. [Univ. of Cuidad, Mexico City (Mexico). Dept. de Termoenergia y Mejoramiento Ambiental

    2006-07-01

    A thermodynamic procedure was developed to analyze the exergy of a rock bed thermal storage unit that used solar power to acclimatize a pig farm. Thermal behaviour was described by means of a control volume that included the entire system and assumed a unidirectional air flow and an adiabatic process. The thermodynamic properties of the system were determined as a function of the experimental temperature profiles developed during thermal storage from solar to thermal energy conversion provided by a solar collector at a fixed mass rate of air flow. Experimental data were used to calculate the energy yield and to determine the entropy generation inside the system. The aim of the study was to determine how well the thermodynamic model matched the real data obtained experimentally during normal operating conditions. Results indicated that an exergy accumulation existed inside the control volume, which was the net result of the energy gain during the heating process. However, entropy generation due to irreversibilities was studied for just 1 air flow. Further research is needed to establish a semi-empirical model of the process with the minimum of entropy generation. It was concluded that the thermal energy storage system was suitable for use in pig farms. 5 refs., 8 figs.

  16. Modified weak energy condition for the energy momentum tensor in quantum field theory

    International Nuclear Information System (INIS)

    Latorre, J.

    1998-01-01

    The weak energy condition is known to fail in general when applied to expectation values of the energy momentum tensor in flat space quantum field theory. It is shown how the usual counter arguments against its validity are no longer applicable if the states vertical stroke ψ right angle for which the expectation value is considered are restricted to a suitably defined subspace. A possible natural restriction on vertical stroke ψ right angle is suggested and illustrated by two quantum mechanical examples based on a simple perturbed harmonic oscillator Hamiltonian. The proposed alternative quantum weak energy condition is applied to states formed by the action of the scalar, vector and the energy momentum tensor operators on the vacuum. We assume conformal invariance in order to determine almost uniquely three-point functions involving the energy momentum tensor in terms of a few parameters. The positivity conditions lead to non-trivial inequalities for these parameters. They are satisfied in free field theories, except in one case for dimensions close to two. Further restrictions on vertical stroke ψ right angle are suggested which remove this problem. The inequalities which follow from considering the state formed by applying the energy momentum tensor to the vacuum are shown to imply that the coefficient of the topological term in the expectation value of the trace of the energy momentum tensor in an arbitrary curved space background is positive, in accord with calculations in free field theories. (orig.)

  17. Wave Runup on a Frozen Beach Under High Energy Conditions

    Science.gov (United States)

    Didier, D.; Bernatchez, P.; Dumont, D.; Corriveau, M.

    2017-12-01

    High and mid-latitude beaches have typical morphological characteristics influenced by nearshore processes prevailing under ice conditions during cold season. Nearshore ice complexes (NIC) offer a natural coastal protection by covering beach sediments, while offshore ice-infested waters dissipate incoming waves. Climate change contributes to sea ice shrinking therefore reducing its protection against erosion and flooding. In the Estuary and Gulf of the St. Lawrence (ESL, GSL) (eastern Canada), sea ice cover undergoes an overall shrinking and simulated future projections tend toward a negligible effect on wave climate by 2100. Quantifying the effect of nearshore dynamics on frozen beaches is therefore imperative for coastal management as more wave energy at the coast is expected in the future. To measure the effect of a frozen beach on wave runup elevations, this study employs a continuous video recording of the swash motion at 4Hz. Video-derived wave runup statistics have been extracted during a tidal cycle on a frozen beach, using the Pointe-Lebel beach (ESL) as a test case. Timestack analysis was combined with offshore water levels and wave measurements. A comparison of runup under icy conditions (Dec. 30 2016) with a runup distribution during summer was made under similar high energy wave conditions. Results indicate high runup excursions potentially caused by lowered sediment permeability due to high pore-ice saturation in the swash zone, accentuating the overwash of the eroding coastline and thus the risk of flooding. With projected reduction in coastal sea ice cover and thus higher wave energy, this study suggests that episodes of degradation and weakening could influence the coastal flood risk in mid- and high-latitude cold environments.

  18. A modal-based approach to the nonlinear vibration of strings against a unilateral obstacle: Simulations and experiments in the pointwise case

    Science.gov (United States)

    Issanchou, Clara; Bilbao, Stefan; Le Carrou, Jean-Loïc; Touzé, Cyril; Doaré, Olivier

    2017-04-01

    This article is concerned with the vibration of a stiff linear string in the presence of a rigid obstacle. A numerical method for unilateral and arbitrary-shaped obstacles is developed, based on a modal approach in order to take into account the frequency dependence of losses in strings. The contact force of the barrier interaction is treated using a penalty approach, while a conservative scheme is derived for time integration, in order to ensure long-term numerical stability. In this way, the linear behaviour of the string when not in contact with the barrier can be controlled via a mode by mode fitting, so that the model is particularly well suited for comparisons with experiments. An experimental configuration is used with a point obstacle either centered or near an extremity of the string. In this latter case, such a pointwise obstruction approximates the end condition found in the tanpura, an Indian stringed instrument. The second polarisation of the string is also analysed and included in the model. Numerical results are compared against experiments, showing good accuracy over a long time scale.

  19. Conditions and need for negotiation in energy policy

    Energy Technology Data Exchange (ETDEWEB)

    Kohler, S.

    1987-01-01

    The use of wind energy has attracted little attention in the official energy policies so far. It is estimated that by the year 2000 about 4 to 7% of primary energy comsumption could be covered by regenerative energy sources. The energy economy regards State help as necessary for using these renewable energy sources. Varying energy supplies from wind energy converters could be accommodated on the grid without any problems. The monopoly of energy supplies tied to transmission lines is regarded as an obstacle in this context. There is reference to relevant wind energy converter-network plans. (HWJ).

  20. The Quantum Focussing Conjecture and Quantum Null Energy Condition

    Science.gov (United States)

    Koeller, Jason

    Evidence has been gathering over the decades that spacetime and gravity are best understood as emergent phenomenon, especially in the context of a unified description of quantum mechanics and gravity. The Quantum Focussing Conjecture (QFC) and Quantum Null Energy Condition (QNEC) are two recently-proposed relationships between entropy and geometry, and energy and entropy, respectively, which further strengthen this idea. In this thesis, we study the QFC and the QNEC. We prove the QNEC in a variety of contexts, including free field theories on Killing horizons, holographic theories on Killing horizons, and in more general curved spacetimes. We also consider the implications of the QFC and QNEC in asymptotically flat space, where they constrain the information content of gravitational radiation arriving at null infinity, and in AdS/CFT, where they are related to other semiclassical inequalities and properties of boundary-anchored extremal area surfaces. It is shown that the assumption of validity and vacuum-state saturation of the QNEC for regions of flat space defined by smooth cuts of null planes implies a local formula for the modular Hamiltonian of these regions. We also demonstrate that the QFC as originally conjectured can be violated in generic theories in d ≥ 5, which led the way to an improved formulation subsequently suggested by Stefan Leichenauer.

  1. Brane surgery: energy conditions, traversable wormholes, and voids

    International Nuclear Information System (INIS)

    Barcelo, Carlos; Visser, Matt

    2000-01-01

    Branes are ubiquitous elements of any low-energy limit of string theory. We point out that negative tension branes violate all the standard energy conditions of the higher-dimensional spacetime they are embedded in; this opens the door to very peculiar solutions of the higher-dimensional Einstein equations. Building upon the (3+1)-dimensional implementation of fundamental string theory, we illustrate the possibilities by considering a toy model consisting of a (2+1)-dimensional brane propagating through our observable (3+1)-dimensional universe. Developing a notion of 'brane surgery', based on the Israel-Lanczos-Sen 'thin shell' formalism of general relativity, we analyze the dynamics and find traversable wormholes, closed baby universes, voids (holes in the spacetime manifold), and an evasion (not a violation) of both the singularity theorems and the positive mass theorem. These features appear generic to any brane model that permits negative tension branes: This includes the Randall-Sundrum models and their variants

  2. Central air conditioning based on adsorption and solar energy

    International Nuclear Information System (INIS)

    Pralon Ferreira Leite, Antonio; Belo, Francisco Antonio; Martins, Moacir Machado; Bressan Riffel, Douglas

    2011-01-01

    This paper presents the characterization and the pre-dimensioning of an adsorption chiller as part of a 20 kW air conditioning central unit for cooling a set of rooms that comprises an area of 110 m 2 . The system is basically made up of a cold water storage tank supplied by an activated carbon-methanol adsorption chiller, a hot water storage tank, fed by solar energy and natural gas, and a fan-coil. During an acclimatization of 8 h (9-17 h), the following parameters were obtained for dimensioning the cooling system: 504 kg of activated carbon, 180 L of methanol, 7000 L of hot water, 10,300 L of cold water with its temperature varying in the fan-coil from 1 deg. C to 14 C. Considering the mean value of the total daily irradiation in Joao Pessoa (7 o 8'S, 34 o 50'WG), and a cover of regenerating heat supplied by solar energy equivalent to 70%, the adsorption chiller's expected coefficient of performance (COP) was found to be around 0.6.

  3. Testing and evaluation of different energy storage devices for piezoelectric energy harvesting under road conditions

    Science.gov (United States)

    Gopalakrishnan, Pratheek

    The increasing needs in green technology have propelled the rapid development in energy conversion and the advancement of electric energy storage systems. A viable storage technology is needed to store intermittent electrical energy in different electronic applications. In this thesis, recent progress on the chemistry and design of batteries is summarized with their challenges and improvements. Along with that, electrolytic capacitors are also reviewed with their types, advantages and disadvantages of each in short. Super capacitors having higher surface area and thinner dielectrics than conventional capacitors along with hybrid capacitors, are discussed in detail. The potential of a hybrid capacitor, Ni(OH)2/ Active Carbon, compared with Ni-Cd batteries and electrolytic capacitors in the application of energy storage for high way energy harvesting has been explored in this work. Both the battery and the hybrid capacitor has been tested under various experimental conditions and their properties in relation to their chemical compositions are compared. The results obtained from the experiments have been analyzed and the most suitable energy storage devices have been selected with their application potential evaluated before drawing conclusion reported in this thesis.

  4. Optimal Time to Invest Energy Storage System under Uncertainty Conditions

    Directory of Open Access Journals (Sweden)

    Yongma Moon

    2014-04-01

    Full Text Available This paper proposes a model to determine the optimal investment time for energy storage systems (ESSs in a price arbitrage trade application under conditions of uncertainty over future profits. The adoption of ESSs can generate profits from price arbitrage trade, which are uncertain because the future marginal prices of electricity will change depending on supply and demand. In addition, since the investment is optional, an investor can delay adopting an ESS until it becomes profitable, and can decide the optimal time. Thus, when we evaluate this investment, we need to incorporate the investor’s option which is not captured by traditional evaluation methods. In order to incorporate these aspects, we applied real option theory to our proposed model, which provides an optimal investment threshold. Our results concerning the optimal time to invest show that if future profits that are expected to be obtained from arbitrage trade become more uncertain, an investor needs to wait longer to invest. Also, improvement in efficiency of ESSs can reduce the uncertainty of arbitrage profit and, consequently, the reduced uncertainty enables earlier ESS investment, even for the same power capacity. Besides, when a higher rate of profits is expected and ESS costs are higher, an investor needs to wait longer. Also, by comparing a widely used net present value model to our real option model, we show that the net present value method underestimates the value for ESS investment and misleads the investor to make an investment earlier.

  5. Nonlinear modeling of magnetorheological energy absorbers under impact conditions

    Science.gov (United States)

    Mao, Min; Hu, Wei; Choi, Young-Tai; Wereley, Norman M.; Browne, Alan L.; Ulicny, John; Johnson, Nancy

    2013-11-01

    Magnetorheological energy absorbers (MREAs) provide adaptive vibration and shock mitigation capabilities to accommodate varying payloads, vibration spectra, and shock pulses, as well as other environmental factors. A key performance metric is the dynamic range, which is defined as the ratio of the force at maximum field to the force in the absence of field. The off-state force is typically assumed to increase linearly with speed, but at the higher shaft speeds occurring in impact events, the off-state damping exhibits nonlinear velocity squared damping effects. To improve understanding of MREA behavior under high-speed impact conditions, this study focuses on nonlinear MREA models that can more accurately predict MREA dynamic behavior for nominal impact speeds of up to 6 m s-1. Three models were examined in this study. First, a nonlinear Bingham-plastic (BP) model incorporating Darcy friction and fluid inertia (Unsteady-BP) was formulated where the force is proportional to the velocity. Second, a Bingham-plastic model incorporating minor loss factors and fluid inertia (Unsteady-BPM) to better account for high-speed behavior was formulated. Third, a hydromechanical (HM) analysis was developed to account for fluid compressibility and inertia as well as minor loss factors. These models were validated using drop test data obtained using the drop tower facility at GM R&D Center for nominal drop speeds of up to 6 m s-1.

  6. Nonlinear modeling of magnetorheological energy absorbers under impact conditions

    International Nuclear Information System (INIS)

    Mao, Min; Hu, Wei; Choi, Young-Tai; Wereley, Norman M; Browne, Alan L; Ulicny, John; Johnson, Nancy

    2013-01-01

    Magnetorheological energy absorbers (MREAs) provide adaptive vibration and shock mitigation capabilities to accommodate varying payloads, vibration spectra, and shock pulses, as well as other environmental factors. A key performance metric is the dynamic range, which is defined as the ratio of the force at maximum field to the force in the absence of field. The off-state force is typically assumed to increase linearly with speed, but at the higher shaft speeds occurring in impact events, the off-state damping exhibits nonlinear velocity squared damping effects. To improve understanding of MREA behavior under high-speed impact conditions, this study focuses on nonlinear MREA models that can more accurately predict MREA dynamic behavior for nominal impact speeds of up to 6 m s −1 . Three models were examined in this study. First, a nonlinear Bingham-plastic (BP) model incorporating Darcy friction and fluid inertia (Unsteady-BP) was formulated where the force is proportional to the velocity. Second, a Bingham-plastic model incorporating minor loss factors and fluid inertia (Unsteady-BPM) to better account for high-speed behavior was formulated. Third, a hydromechanical (HM) analysis was developed to account for fluid compressibility and inertia as well as minor loss factors. These models were validated using drop test data obtained using the drop tower facility at GM R and D Center for nominal drop speeds of up to 6 m s −1 . (paper)

  7. Nuclear energy and politics in Russian ATWS conditions

    International Nuclear Information System (INIS)

    Gagarinski, A.

    1998-01-01

    Relations between politics and nuclear power in the countries of sustainable development has been many times discussed during the short history of nuclear energy, and regularly arising new events, even very important (in Sweden, USA, etc.), just add to the formed understanding of the problem. Russia for 10 years lives in conditions of a transition period, which seems similar to ATWS-type accidents at nuclear power plants. In these conditions the effect of politics on nuclear power and vice versa are seen very clearly, and, more important, change swiftly, which may present interest for the countries with smoother public processes. The role of political processes in nuclear power is obvious and may be reduced to three main factors: change of political system and transition to market economy have placed nuclear power, though still within state sector, in an absolutely new economic condition, which determine its today's situation as 'Survival'; new possibilities of political influence and opposition to nuclear power (mainly struggle against construction of new nuclear fuel cycle objects) on a levels of authority (local, regional, federal); impact of the USSR collapse on the situation in Russian nuclear power was due sooner to temporary weakening of control and regulatory structures, than to the fact, that some fuel cycle elements have found themselves abroad (the factor of uranium resources' loss is unimportant at present). Nuclear safety was chosen to be the subject of Moscow 1996 Summit, initiated with the purpose of Russia coming closer to G7. The Summit has confirmed the thesis on the possibility of nuclear power o play an important role in the world energy demand in accordance with sustainable development goals. successful activities of Russia-USA Commission for economic and technological cooperation, known as 'Gore-Chernomyrdin' Commission, is to a large extent determined by positive nuclear decisions. Eastern direction of Russian nuclear export (Iran, China

  8. The global mean energy balance under cloud-free conditions

    Science.gov (United States)

    Wild, Martin; Hakuba, Maria; Folini, Dois; Ott, Patricia; Long, Charles

    2017-04-01

    A long standing problem of climate models is their overestimation of surface solar radiation not only under all-sky, but also under clear-sky conditions (Wild et al. 1995, Wild et al. 2006). This overestimation reduced over time in consecutive model generations due to the simulation of stronger atmospheric absorption. Here we analyze the clear sky fluxes of the latest climate model generation from the Coupled Model Intercomparison Project Phase 5 (CMIP5) against an expanded and updated set of direct observations from the Baseline Surface Radiation Network (BSRN). Clear sky climatologies from these sites have been composed based on the Long and Ackermann (2000) clear sky detection algorithm (Hakuba et al. 2017), and sampling issues when comparing with model simulated clear sky fluxes have been analyzed in Ott (2017). Overall, the overestimation of clear sky insolation in the CMIP5 models is now merely 1-2 Wm-2 in the multimodel mean, compared to 4 Wm-2 in CMIP3 and 6 Wm-2 in AMIPII (Wild et al. 2006). Still a considerable spread in the individual model biases is apparent, ranging from -2 Wm-2 to 10 Wm-2 when averaged over 53 globally distributed BSRN sites. This bias structure is used to infer best estimates for present day global mean clear sky insolation, following an approach developped in Wild et al. (2013, 2015, Clim. Dyn.) for all sky fluxes. Thereby the flux biases in the various models are linearly related to their respective global means. A best estimate can then be inferred from the linear regression at the intersect where the bias against the surface observations becomes zero. This way we obtain a best estimate of 247 Wm-2 for the global mean insolation at the Earth surface under cloud free conditions, and a global mean absorbed solar radiation of 214 Wm-2 in the cloud-free atmosphere, assuming a global mean surface albedo of 13.5%. Combined with a best estimate for the net influx of solar radiation at the Top of Atmosphere under cloud free conditions

  9. Proceedings of the 12. forum: Croatian Energy Day: Energy consumers in open market conditions

    International Nuclear Information System (INIS)

    Granic, G.; Jelavic, B.

    2003-01-01

    The theme of the 12. Forum: Energy Day in Croatia is energy sector liberalisation and the new position of the consumers, changing rapidly and acquiring a completely new perspective. By means of market opening of various energy forms the consumer gains right to choose the energy supplier, quite a radical change in relation to the former, monopolistic relationship. This means that the consumer becomes the centre of attention, as has already been achieved at the mobile phone market. Within new market environment, the consumer becomes product buyer, buyer of the product in principle bearing market characteristics as any other product. However, energy markets reveal numerous peculiarities, distinguishing them from the markets of goods and services, as we have known them for centuries, which function according to well-known market conditions. While part of the energy sector will permanently remain a natural monopoly (transmission / transportation and distribution networks), the opening of the considered market requires information science development, which means it is necessary to apply advanced technology for e.g. measuring devices, etc. In view of such market circumstances it is essential to define the quality of the product including supply stability, voltage quality or agility in responding to customer complaints. On the other hand, these factors cannot be adjusted to each individual consumer-buyer at the moment or at least not ones. The position of the customers-buyers has been solved differently in various countries. The aim of this Forum is to put forward and explain experience and solutions connected to the new customer-buyer role in market circumstances. It is our wish that the participants discuss problems connected to the consumer-buyer position under the following aspects: Present status of market opening for various energy forms in the countries of the EU and in the transition countries; technical preconditions for energy market opening such as information

  10. THE CONDITIONS OF INVESTMENTS IN RENEWABLE ENERGY IN POLAND

    OpenAIRE

    Grzegorz Masloch

    2009-01-01

    In the article the author shows the problems that enterprises investing in renewable energy production have to face. Taking into consideration Poland’s obligations regarding the development of the production of renewable energy, activities aiming at environmental protection and the possibilities of getting EU funding of ecological investments, the paper’s subject matter seems particularly significant.

  11. Retrofitting Inefficient Rooftop Air-Conditioning Units Reduces U.S. Navy Energy Use (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-04-01

    As part of the U.S. Navy's overall energy strategy, the National Renewable Energy Laboratory (NREL) partnered with the Naval Facilities Engineering Command (NAVFAC) to demonstrate market-ready energy efficiency measures, renewable energy generation, and energy systems integration. One such technology - retrofitting rooftop air-conditioning units with an advanced rooftop control system - was identified as a promising source for reducing energy use and costs, and can contribute to increasing energy security.

  12. The transition towards renewable energies: Physical limits and temporal conditions

    International Nuclear Information System (INIS)

    Mediavilla, Margarita; Castro, Carlos de; Capellán, Iñigo; Javier Miguel, Luis; Arto, Iñaki; Frechoso, Fernando

    2013-01-01

    The perspectives of the depletion of fossil energy resources, together with the consequences of climate change, have provoked the development of numerous national and pluri-national energy policies. However, there have been few overall studies on the evolution of these resources. This paper uses a dynamic model to study the exhaustion patterns of world fossil and nuclear fuels and their possible replacement by renewable energy sources. The results show that peak oil will be the first restriction and it will not be easily overcome. Electric vehicles can produce some interesting savings, but they are insufficient to avoid the decline in oil. Biofuels are even more limited, due to the enormous extensions of fertile land they require and their low productivity. This shows that overcoming the decline in oil will need much more ambitious policies than the mere substitution of technology. If the “oil–economy” relationship does not change substantially, world economic growth may be seriously limited or even negative. In contrast, the production of electrical energy is not such a worrying problem in the short and middle-term. - Highlights: ► We study world energy demand and resources with a systems dynamics model. ► We find that peak oil cannot be overcomed with simple technological substitution. ► Past economic growth and energy intensity trends cannot be maintained. ► Electric vehicles are only a partial solution, biofuels are even more limited. ► Substitution of electric energy by renewables is much easier than oil substitution.

  13. BCG: a code for calculating pointwise neutron spectra and criticality in fast reactor cells

    International Nuclear Information System (INIS)

    Leite, S.B.; Caldeira, A.D.; Garcia, R.D.M.

    1988-02-01

    The BCG code for determining the space and energy neutron flux distribution and criticality of fast reactor cylindrical cells is presented. The code solves the unidimensional neutron transport equation together with interface current relations at each energy in an unionized grid prepared for the cell and at an arbitrary number of spatial zones. While the spatial resolution is user specified, the energy dependence of the flux distribution is resolved according to the degree of variation in the reconstructed total microscopic cross sections of the atomic species in the cell. Results for a defined sample problem illustrate the high resolution and accuracy that can be obtained with the code. (author) [pt

  14. Smart buildings: Energy efficient conditioning of building occupants

    NARCIS (Netherlands)

    Zeiler, W.; Houten, van M.A.; Boxem, G.; Vehler, R.; Verhoeven, M.; Fremouw, M.

    2009-01-01

    To further optimize energy performance of buildings, intelligent building control offers new possibilities. Intelligent Software Agents (ISA) can be implemented at different levels of building automation. Individual agents for individual climate control for each user of the building in combination

  15. Energy storage and power conditioning system for the Shiva laser

    International Nuclear Information System (INIS)

    Allen, G.R.; Gagnon, W.L.; Rupert, P.R.; Trenholme, J.B.

    1975-01-01

    An optimal energy delivery system for the world's largest glass laser system has been designed based on computer modeling and operation of laser hardware. Components of the system have been tested on operating lasers at LLL. The Shiva system is now under construction and will be completed in 1977. The energy supply described here will provide cost-effective, reliable power and facilitate the gathering of data in pursuit of controlled thermonuclear reactions

  16. Evaluation of the energy and comfort performance of a plus-energy house under Scandinavian winter conditions

    DEFF Research Database (Denmark)

    Pean, Thibault Quentin; Gennari, Luca; Kazanci, Ongun Berk

    evaluation, these results show an encouraging trend towards achieving an annual positive energy balance as designed for this plus-energy house. The thermal environmental conditions in the semi-outdoor space resulted more comfortable than the outdoors, with reduced wind velocity, protection from rain......A plus-energy house was studied in terms of indoor environmental conditions and energy balance, during Scandinavian winter conditions. The studied building, EMBRACE, is a single-family detached dwelling of 59 m2 with two floors. The house also integrates a semi-outdoor space, covered by a glazed...

  17. Changing Energy Requirements in the Mediterranean Under Changing Climatic Conditions

    Directory of Open Access Journals (Sweden)

    George Demosthenous

    2009-09-01

    Full Text Available This study investigates the impacts of climate change on energy requirements in the Mediterranean. Energy requirements, especially for space heating and cooling, are closely linked to several weather variables, mainly air temperature. The analysis is based on daily temperature outputs from several regional climate models run at a resolution of 25 km × 25 km in the framework of EU project ENSEMBLES using the A1B emissions scenario. The impacts of changes in temperature on energy requirements are investigated using the concept of degree days, defined as the difference of mean air temperature from a base temperature. Base temperature should be chosen to coincide with the minimum energy consumption. In this way, changes in heating and cooling requirements between the reference and the future period are calculated and areas about to undergo large changes identified. These changes are calculated between a 30-year reference period 1961–1990 and a near future period 2021–2050 taking the ensemble mean of all regional climate models. The near-term future has been chosen instead of the frequently used end-of-the-century period to assist policy makers in their planning. In general, a decrease in energy requirements is projected under future milder winters and an increase under hotter summers.

  18. Energy behavior of solar hot water systems under different conditions

    International Nuclear Information System (INIS)

    Fuentes Lombá, Osmanys; Torres Ten, Alonso; Arzuaga Machado, Yusnel; Hernández, Massipe J. Raúl; Cueva Gonzales, Wagner

    2017-01-01

    By means of numerical simulations in TRNSYS v14 the influence of the solar absorption area of a system for heating water with solar energy, composed by a flat solar collector and a tank thermo-accumulator, on its energy efficiency. For the study, the solar collectors EDWARDS, ISOFOTÓN 1, ISOFOTÓN 2, MADE, ROLDAN and IBERSOLAR of absorption area 2, 1,9, 1,88, 2, 1,9 and 2,3 m2 respectively were chosen. For each collector, the energy performance was simulated for one year, setting 200 L for the accumulation volume and 50 °C for the intake temperature. Despite the different characteristics of each collector, their behavior is quite similar showing a very mature technology. (author)

  19. Political boundary conditions for a reliable energy supply

    International Nuclear Information System (INIS)

    Majewski, O.

    1994-01-01

    The further course of energy policy in Germany is completely uncertain, especially in the light of the elections to be held in Germany in 1994. At the very last minute, the attempt at finding a long-term energy consensus failed although the positions held by the participants from politics, industry, and other groupings had already come much closer. Against the backdrop of a profound recession and a structural crisis of industry, on the one hand, and increasingly tougher international competition, on the other hand, the parameters of energy policy contribute greatly to the success or failure of future economic development. One of the objectives of the consensus talks had been to maintain an energy mix so as to spread more widely the economic, technical, political, and ecological risks that would be encountered. In particular, a permanent perspective was to be developed for the peaceful uses of nuclear power, on the one hand, by ensuring the politically undisturbed operation of the nuclear power plants currently in operation and, on the other hand, by creating a concrete, sustainable option for the development and operation of an advanced generation of nuclear reactors. (orig.) [de

  20. Detection of progression of glaucomatous visual field damage using the point-wise method with the binomial test.

    Science.gov (United States)

    Karakawa, Ayako; Murata, Hiroshi; Hirasawa, Hiroyo; Mayama, Chihiro; Asaoka, Ryo

    2013-01-01

    To compare the performance of newly proposed point-wise linear regression (PLR) with the binomial test (binomial PLR) against mean deviation (MD) trend analysis and permutation analyses of PLR (PoPLR), in detecting global visual field (VF) progression in glaucoma. 15 VFs (Humphrey Field Analyzer, SITA standard, 24-2) were collected from 96 eyes of 59 open angle glaucoma patients (6.0 ± 1.5 [mean ± standard deviation] years). Using the total deviation of each point on the 2(nd) to 16(th) VFs (VF2-16), linear regression analysis was carried out. The numbers of VF test points with a significant trend at various probability levels (pbinomial test (one-side). A VF series was defined as "significant" if the median p-value from the binomial test was binomial PLR method (0.14 to 0.86) was significantly higher than MD trend analysis (0.04 to 0.89) and PoPLR (0.09 to 0.93). The PIS of the proposed method (0.0 to 0.17) was significantly lower than the MD approach (0.0 to 0.67) and PoPLR (0.07 to 0.33). The PBNS of the three approaches were not significantly different. The binomial BLR method gives more consistent results than MD trend analysis and PoPLR, hence it will be helpful as a tool to 'flag' possible VF deterioration.

  1. Design of energy efficient ventilation and air-conditioning systems

    CERN Document Server

    Seppänen, Olli; Bertilsson, Thore; Maripuu, Mari-Liis; Lamy, Hervé; Vanden Borre, Alex

    2012-01-01

    This guidebook covers numerous system components of ventilation and air-conditioning systems and shows how they can be improved by applying the latest technology products. Special attention is paid to details, which are often overlooked in the daily design practice, resulting in poor performance of high quality products once they are installed in the building system.

  2. Silicon passivation study under low energy electron irradiation conditions

    International Nuclear Information System (INIS)

    Cluzel, R.

    2010-01-01

    Backside illuminated thinned CMOS (Complementary Metal Oxide Semiconductor) imaging system is a technology developed to increase the signal to noise ratio and the sensibility of such sensors. This configuration is adapted to the electrons detection from the energy range of [1 - 12 keV]. The impinging electron creates by multiplication several hundreds of secondary electrons close to the surface. A P ++ highly-doped passivation layer of the rear face is required to reduce the secondary electron surface recombination rate. Thanks to the potential barrier induced by the P ++ layer, the passivation layer increases the collected charges number and so the sensor collection gain. The goal of this study is to develop some experimental methods in order to determine the effect of six different passivation processes on the collection gain. Beforehand, the energy profile deposited by an incident electron is studied with the combination of Monte-Carlo simulations and some analytical calculations. The final collection gain model shows that the mirror effect from the passivation layer is a key factor at high energies whereas the passivation layer has to be as thin as possible at low energies. A first experimental setup which consists in irradiating P ++ /N large diodes allows to study the passivation process impacts on the surface recombinations. Thanks to a second setup based on a single event upset directly on thinned CMOS sensor, passivation techniques are discriminated in term of mirror effect and the implied spreading charges. The doping atoms activation laser annealing is turn out to be a multiplication gain inhomogeneity source impacting directly the matrix uniformity. (author)

  3. Using the renewable energy sources in the market conditions

    International Nuclear Information System (INIS)

    Kozlov, V.B.

    2000-01-01

    Raper studies the peculiarities of financing of projects for the renewable energy sources (RES) in cooperation with the Kyoto protocol as to the regulating principles of purchase (sale) of quotas for greenhouse gas release. The records of the results obtained in the West European countries and USA as to payment of green electricity generated on the basis of RES application is analyzed. Preliminary estimation of cost ratio of quotas for releases of greenhouse gases for conventional power plants and RES based ones is presented [ru

  4. High-energy synchrotron x-ray diffraction studies on disordered materials. From ambient condition to an extreme condition

    International Nuclear Information System (INIS)

    Kohara, Shinji; Ohishi, Yasuo; Suzuya, Kentaro; Takata, Masaki

    2007-01-01

    High-energy x-rays from synchrotron radiation source allow us to measure high-quality diffraction data of the disordered materials from under ambient condition to an extreme condition, which is necessary to reveal the detailed structure of glass, liquid, and amorphous materials. We introduce the high-energy x-ray diffraction beamline and dedicated diffractometer for glass, liquid, and amorphous materials with the recent developments of ancillary equipments. Furthermore our recent studies on the structures of disordered materials reviewed. (author)

  5. Energy and environment market conditions in Mexico. Business focus series

    International Nuclear Information System (INIS)

    1992-03-01

    The report provides: (1) an overview of the Mexican economy and the energy and environmental sectors; (2) specific market assessments of the oil and gas sector, the electric power sector, the industrial air pollution control sector, and the municipal and industrial water pollution control sector; and (3) an analysis of the Mexican business climate and procedures. Each of the sectors is projected to show significant growth over the next several years. The Mexican government has taken many positive steps to improve the country's business climate, including trade and foreign exchange liberalization, foreign investment incentives, and strengthened intellectual property regulation. The North American Free Trade Agreement is expected to further improve the business climate in Mexico

  6. Local modular Hamiltonians from the quantum null energy condition

    Science.gov (United States)

    Koeller, Jason; Leichenauer, Stefan; Levine, Adam; Shahbazi-Moghaddam, Arvin

    2018-03-01

    The vacuum modular Hamiltonian K of the Rindler wedge in any relativistic quantum field theory is given by the boost generator. Here we investigate the modular Hamiltonian for more general half-spaces which are bounded by an arbitrary smooth cut of a null plane. We derive a formula for the second derivative of the modular Hamiltonian with respect to the coordinates of the cut which schematically reads K''=Tv v . This formula can be integrated twice to obtain a simple expression for the modular Hamiltonian. The result naturally generalizes the standard expression for the Rindler modular Hamiltonian to this larger class of regions. Our primary assumptions are the quantum null energy condition—an inequality between the second derivative of the von Neumann entropy of a region and the stress tensor—and its saturation in the vacuum for these regions. We discuss the validity of these assumptions in free theories and holographic theories to all orders in 1 /N .

  7. A singular perturbation limit of diffused interface energy with a fixed contact angle condition

    OpenAIRE

    Kagaya, Takashi; Tonegawa, Yoshihiro

    2016-01-01

    We study a general asymptotic behavior of critical points of a diffused interface energy with a fixed contact angle condition defined on a domain $\\Omega \\subset \\mathbb{R}^n$. We show that the limit varifold derived from the diffused energy satisfies a generalized contact angle condition on the boundary under a set of assumptions.

  8. Three-dimensional microarchitected materials and devices using nanoparticle assembly by pointwise spatial printing.

    Science.gov (United States)

    Saleh, Mohammad Sadeq; Hu, Chunshan; Panat, Rahul

    2017-03-01

    Three-dimensional (3D) hierarchical materials are important to a wide range of emerging technological applications. We report a method to synthesize complex 3D microengineered materials, such as microlattices, with nearly fully dense truss elements with a minimum diameter of approximately 20 μm and having high aspect ratios (up to 20:1) without using any templating or supporting materials. By varying the postprocessing conditions, we have also introduced an additional control over the internal porosity of the truss elements to demonstrate a hierarchical porous structure with an overall void size and feature size control of over five orders of magnitudes in length scale. The method uses direct printing of nanoparticle dispersions using the Aerosol Jet technology in 3D space without templating or supporting materials followed by binder removal and sintering. In addition to 3D microlattices, we have also demonstrated directly printed stretchable interconnects, spirals, and pillars. This assembly method could be implemented by a variety of microdroplet generation methods for fast and large-scale fabrication of the hierarchical materials for applications in tissue engineering, ultralight or multifunctional materials, microfluidics, and micro-optoelectronics.

  9. From cutting-edge pointwise cross-section to groupwise reaction rate: A primer

    Science.gov (United States)

    Sublet, Jean-Christophe; Fleming, Michael; Gilbert, Mark R.

    2017-09-01

    of the nuclear physics that is so important for many areas of science and technology; advanced fission and fuel systems, magnetic and inertial confinement fusion, high energy, accelerator physics, medical application, isotope production, earth exploration, astrophysics and homeland security.

  10. MIGRATIONS OF RELEASED SEISMIC ENERGY IN VARIOUS GEODYNAMIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    A. V. Novopashina

    2018-01-01

    Full Text Available The properties of slow seismic activity migration have been revealed by the space-time analysis of the total earthquake energy (LgEsum. Our study of seismic activity covers the fragments of  the Central Asian, Pacific and Alpine seismic belts: the Baikal rift system (BRS, Russia, the San Andreas fault zone (California, USA, the Christchurch fault (New Zealand, the North and East Anatolian faults (Turkey, the Philippine subduction zone, and the central fragment of the Mid-Atlantic oceanic ridge. The chains of LgEsum clusters mark the propagation of the maximum stresses front in the weaker crust areas, the zones of fault dynamic influence, and the regions of conjugated tectonic structures. The migration process is characterized by a periodicity, changes in direction, and similar modular values of the migration rates within a single fault segment (or a fault zone, which is probably related to the mechanical and rheological crust and upper mantle properties. The data analysis shows that a strong earthquake source may occur at a location wherein the front of seismic activity propagates with periodical changes in direction, and such a source can develop within a period that is multiple of the migration fluctuations, probably associated with the influence of external periodic factors. The main periods of migration fluctuations (2–4 years, and 9–13 years, in different ratios are present in the seismic regimes of different seismic belts. The migration rate, as well as the propagation velocity of the maximum stresses front, directly depends on the velocity of movements between the plates in the region.

  11. From cutting-edge pointwise cross-section to groupwise reaction rate: A primer

    Directory of Open Access Journals (Sweden)

    Sublet Jean-Christophe

    2017-01-01

    sustainable understanding of the nuclear physics that is so important for many areas of science and technology; advanced fission and fuel systems, magnetic and inertial confinement fusion, high energy, accelerator physics, medical application, isotope production, earth exploration, astrophysics and homeland security.

  12. The public debate on the energy in France: the issue conditions; Le debat public sur l'energie en France: les conditions de la reussite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This session on the issue conditions of the public debate on the energy, took place around two presentations. The first one dealt with public debate cases analysis, the Souviron, the citizen conference and the CNDP (national Commission of Public Debate) models. The second one wondered on the debate objectives, key of the debate issue. (A.L.B.)

  13. An energy performance assessment for indoor environmental quality (IEQ) acceptance in air-conditioned offices

    International Nuclear Information System (INIS)

    Wong, L.T.; Mui, K.W.

    2009-01-01

    Maintaining an acceptable indoor environmental quality (IEQ) for air-conditioned office buildings consumes a considerable amount of thermal energy. This study correlates thermal energy consumption with the overall occupant acceptance of IEQ in some air-conditioned offices. An empirical expression of an IEQ index associated with thermal comfort, indoor air quality, aural and visual comfort is used to benchmark the offices. Employing input parameters obtained from the building stocks of Hong Kong, the office portfolios regarding the thermal energy consumption and the IEQ index are determined by Monte Carlo simulations. In particular, an energy-to-acceptance ratio and an energy-to-IEQ improvement ratio are proposed to measure the performance of energy consumption for the IEQ in the air-conditioned offices. The ratios give the thermal energy consumption corresponding to a desirable percentage of IEQ acceptances and to an IEQ upgrade, respectively. The results showed a non-linear increasing trend of annual thermal energy consumption for IEQ improvement at the offices of higher IEQ benchmarks. The thermal energy consumption for visual comfort and indoor air quality would also be significant in these offices. This study provides useful information that incorporates the IEQ in air-conditioned offices into the development of performance evaluation measures for thermal energy consumption.

  14. Energy Conversion and Transmission Characteristics Analysis of Ice Storage Air Conditioning System Driven by Distributed Photovoltaic Energy System

    Directory of Open Access Journals (Sweden)

    Yongfeng Xu

    2016-01-01

    Full Text Available In order to reduce the investment and operation cost of distributed PV energy system, ice storage technology was introduced to substitute batteries for solar energy storage. Firstly, the ice storage air conditioning system (ISACS driven by distributed photovoltaic energy system (DPES was proposed and the feasibility studies have been investigated in this paper. And then, the theoretical model has been established and experimental work has been done to analyze the energy coupling and transferring characteristics in light-electricity-cold conversion process. In addition, the structure optimization analysis was investigated. Results revealed that energy losses were high in ice making process of ice slide maker with only 17.38% energy utilization efficiency and the energy efficiency and exergy efficiency of ISACS driven by DPES were 5.44% and 67.30%, respectively. So the immersed evaporator and cointegrated exchanger were adopted for higher energy utilization efficiency and better financial rewards in structure optimization. The COP and exergy efficiency of ice maker can be increased to 1.48 and 81.24%, respectively, after optimization and the energy utilization efficiency of ISACS driven by DPES could be improved 2.88 times. Moreover, ISACS has the out-of-the-box function of ordinary air conditioning system. In conclusion, ISACS driven by DPES will have good application prospects in tropical regions without power grid.

  15. Present developmental conditions petroleum substituting energies in the EU; Sekiyu daitai energy kaihatsu no genjo (EU)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This report outlines the policy of development and introduction of petroleum substituting energies, and its diffusion situation in the EU. On the policy, development, introduction and diffusion of petroleum substituting energies in the EU, based on the new EU energy white paper issued in fiscal 1996, the policy of energy and environment in every EU country is first outlined. The policy of and practical approach to petroleum substituting energies in every EU country are next described. In particular, since ALTENER which has been continuously promoted by the EU for 3 years as main control measures against CO2 is newly moving toward the second plan, the trend of ALTENER and the new SAVE2 plan are presented. The content of JOULE-THERMIE is also precisely presented which is the new energy program of the 4th framework R & D program. In relation to the developmental trend of alternative energies to oil in the EU until 2020, its prediction result is presented on the basis of the latest study promoted by EC committee in the ALTENER plan. 10 tabs.

  16. Energy managemant through PCM based thermal storage system for building air-conditioning: Tidel Park, Chennai

    International Nuclear Information System (INIS)

    Nallusamy, N.; Sampath, S.; Velraj, R.

    2006-01-01

    Many modern building are designed for air-conditioning and the amount of electrical energy required for providing air-conditioning can be very significant especially in the tropics. Conservation of energy is major concern to improve the overall efficiency of the system. Integration is energy storage with the conventional system gives a lot of potential for energy saving and long-term economics. Thermal energy storage systems can improve energy management and help in matching supply and demand patterns. In the present work, a detailed study has been done on the existing thermal energy storage system used in the air-conditioning system in Tidel Park, Chennai. The present study focuses on the cool energy storage system. The modes of operation and advantages of such a system for energy management are highlighted. The reason for the adoption of combined storage system and the size of the storage medium in the air-conditioning plant are analyzed. The possibility of using this concept in other cooling and heating applications, such as storage type solar water heating system, has been explored

  17. Forthcoming break-even conditions of tokamak plasma performance for fusion energy development

    International Nuclear Information System (INIS)

    Hiwatari, Ryoji; Okano, Kunihiko; Asaoka, Yoshiyuki; Tokimatsu, Koji; Konishi, Satoshi; Ogawa, Yuichi

    2005-01-01

    The present study reveals forthcoming break-even conditions of tokamak plasma performance for the fusion energy development. The first condition is the electric break-even condition, which means that the gross electric power generation is equal to the circulating power in a power plant. This is required for fusion energy to be recognized as a suitable candidate for an alternative energy source. As for the plasma performance (normalized beta value β N , confinement improvement factor for H-mode HH, the ratio of plasma density to Greenwald density fn GW ), the electric break-even condition requires the simultaneous achievement of 1.2 N GW tmax =16 T, thermal efficiency η e =30%, and current drive power P NBI N ∼1.8, HH≠1.0, and fn GW ∼0.9, which correspond to the ITER reference operation parameters, have a strong potential to achieve the electric break-even condition. The second condition is the economic break-even condition, which is required for fusion energy to be selected as an alternative energy source in the energy market. By using a long-term world energy scenario, a break-even price for introduction of fusion energy in the year 2050 is estimated to lie between 65 mill/kWh and 135 mill/kWh under the constraint of 550 ppm CO 2 concentration in the atmosphere. In the present study, this break-even price is applied to the economic break-even condition. However, because this break-even price is based on the present energy scenario including uncertainties, the economic break-even condition discussed here should not be considered the sufficient condition, but a necessary condition. Under the conditions of B tmax =16 T, η e =40%, plant availability 60%, and a radial build with/without CS coil, the economic break-even condition requires β N ∼5.0 for 65 mill/kWh of lower break-even price case. Finally, the present study reveals that the demonstration of steady-state operation with β N ∼3.0 in the ITER project leads to the upper region of the break

  18. Forthcoming Break-Even Conditions of Tokamak Plasma Performance for Fusion Energy Development

    Science.gov (United States)

    Hiwatari, Ryoji; Okano, Kunihiko; Asaoka, Yoshiyuki; Tokimatsu, Koji; Konishi, Satoshi; Ogawa, Yuichi

    The present study reveals forthcoming break-even conditions of tokamak plasma performance for the fusion energy development. The first condition is the electric break-even condition, which means that the gross electric power generation is equal to the circulating power in a power plant. This is required for fusion energy to be recognized as a suitable candidate for an alternative energy source. As for the plasma performance (normalized beta value ΒN), confinement improvement factor for H-mode HH, the ratio of plasma density to Greenwald density fnGW), the electric break-even condition requires the simultaneous achievement of 1.2 market. By using a long-term world energy scenario, a break-even price for introduction of fusion energy in the year 2050 is estimated to lie between 65 mill/kWh and 135 mill/kWh under the constraint of 550 ppm CO2 concentration in the atmosphere. In the present study, this break-even price is applied to the economic break-even condition. However, because this break-even price is based on the present energy scenario including uncertainties, the economic break-even condition discussed here should not be considered the sufficient condition, but a necessary condition. Under the conditions of Btmax = 16 T, ηe = 40 %, plant availability 60 %, and a radial build with/without CS coil, the economic break-even condition requires ΒN ˜ 5.0 for 65 mill/kWh of lower break-even price case. Finally, the present study reveals that the demonstration of steady-state operation with ΒN ˜ 3.0 in the ITER project leads to the upper region of the break-even price in the present world energy scenario, which implies that it is necessary to improve the plasma performance beyond that of the ITER advanced plasma operation.

  19. Energy efficiency index to artificially conditioned buildings; Indice de eficiencia energetica para edificios climatizados artificialmente

    Energy Technology Data Exchange (ETDEWEB)

    Jota, Patricia Romeiro da Silva; Santos, Carla da Silva; Costa, Kelly Luciene C. [Centro Federal de Educacao Tecnologica de Minas Gerais (CEMIG/CEFET), Belo Horizonte, MG (Brazil). Centro de Pesquisa em Energia Inteligente

    2010-07-01

    Conditioning buildings has been growing in number and are responsible for a significant portion of the energy used worldwide. The building energy use can be measured by the index of energy performance and specific fuel consumption (EC). The specific consumption is an index where the energy is normalized by the factors that affect energy use in order to obtain an index to explain variations in consumption. In this paper, we present a methodology to obtain a specific consumption that takes into account one of the factors that most affect energy use in these buildings, that is, the external temperature. The study is based on analysis of consumption of air conditioning system according to temperature. Through this analysis we obtain a function to facilitate the standardization of energy use, depending on the temperature outside. This methodology was tested in previous work on real buildings without stratification of energy, and this work will be presented a case study of a building whose energy measurement is stratified. The proposed index is the ratio between the energy consumption of air conditioning system corrected by the temperature through the function K(T). It was possible to demonstrate the efficiency of the index to eliminate the effect of temperature and thus to evaluate the evolution of specific consumption over the months analyzed. (author)

  20. Energy impact of indoor environmental policy for air-conditioned offices of Hong Kong

    International Nuclear Information System (INIS)

    Wong, L.T.; Mui, K.W.; Shi, K.L.

    2008-01-01

    Air-conditioned office buildings are one of the biggest energy consumers of electricity in developed cities in the subtropical climate regions. A good energy policy for the indoor environment should respond to both the needs of energy conservation and the needs for a desirable indoor healthy environment with a reduction in carbon dioxide (CO 2 ) generation. This study evaluates energy implications and the corresponding CO 2 generation of some indoor environmental policies for air-conditioned office buildings in the subtropical climate. In particular, the thermal energy consumption in an air-conditioned office building was evaluated by the heat gains through the building fabric, the transport of outdoor fresh air for ventilation, and the heat generated by the occupant and equipment in the space. With the Monte-Carlo sampling technique and the parameters from the existing office building stocks of Hong Kong, the energy consumption profiles of air-conditioned office buildings in Hong Kong were evaluated. Energy consumption profiles were simulated for certain indoor environmental quality (IEQ) policies on indoor air temperature and CO 2 concentration settings in the offices, with other building parameters remaining unchanged. The impact assessment and the regression models described in this study may be useful for evaluation of energy performances of IEQ policies. They will also be useful for the promotion of energy-saving measures in air-conditioned office buildings in Hong Kong. This study presented a useful source of references for policymakers, building professionals and end users to quantify the energy and environmental impacts due to an IEQ policy for air-conditioned office buildings

  1. Analysis of wind energy generation possibilities with various rotor types at disadvantageous wind condition zones

    OpenAIRE

    Bieniek Andrzej

    2017-01-01

    The paper describe possibilities of energy generation using various rotor types but especially with multi-blade wind engine operates in the areas with unfavourable wind condition. The paper presents also wind energy conversion estimation results presented based on proposed solution of multi-blade wind turbine of outer diameter of 4 m. Based on the wind distribution histogram from the disadvantage wind condition zones (city of Basel) and taking into account design and estimated operating index...

  2. Present developmental conditions of petroleum substituting energies in France; Sekiyu daitai energy kaihatsu no genjo (France)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The French Government most enthusiastically promotes development of bio-gasoline in renewable energy field. EU makes pressure to remove the French Government`s fiscal advantages for bio-gasoline which only benefit French farmers, and the IEA (International Energy Agency) report also estimates no benefit corresponding to the fiscal support cost. Start of the `Eolien 2005` project is attractive in renewable energy field which aims at construction of wind power generation stations of 250-500MW by 2005. The `Eolien 2005` project is mainly supported by Electricite de France (EDF) who guarantees the purchase of produced electric power at a submitted price. In addition to this subsidy activity, EDF decided to positively tackle renewable energy. On R and D efforts for renewable energy, France belongs to the most poor countries among IEA countries, and in addition, the effort is considerably concentrated onto the study on reduction of production cost for bio-gasoline. There were no changes in this situation in 1996. 7 refs., 5 figs., 31 tabs.

  3. Energy-autonomous wireless vibration sensor for condition-based maintenance of machinery

    NARCIS (Netherlands)

    Wang, Z.; Bouwens, F.; Vullers, R.; Petré, F.; Devos, S.

    2011-01-01

    This paper addresses the development of an energy-autonomous wireless vibration sensor for condition-based monitoring of machinery. Such technology plays an increasingly important role in modern manufacturing industry. In this work, energy harvesting is realized by resorting to a custom designed

  4. Enthalpy estimation for thermal comfort and energy saving in air conditioning system

    International Nuclear Information System (INIS)

    Chu, C.-M.; Jong, T.-L.

    2008-01-01

    The thermal comfort control of a room must consider not only the thermal comfort level but also energy saving. This paper proposes an enthalpy estimation that is conducive for thermal comfort control and energy saving. The least enthalpy estimator (LEE) combines the concept of human thermal comfort with the theory of enthalpy to predict the load for a suitable setting pair in order to maintain more precisely the thermal comfort level and save energy in the air conditioning system

  5. Create the conditions - renewable energy and energy storage policies choices for island nations

    International Nuclear Information System (INIS)

    Timmins, Thomas

    2015-01-01

    This fast moving, detailed presentation offers an in-depth look at the development, launch and renewal of renewable energy procurement programs worldwide, with an eye to (a) educating renewable energy policy makers and procurement program designers with up-to-date information on issues, investor concerns and trends from island nations around the globe, (b) informing industry participants and industry advocates regarding divergent public policy choices facing policy makers, and (c) helping industry stakeholders to assist public policy choice makers in formulating effective and sustainable policy choices. (full text)

  6. Modelling of domestic refrigerators' energy consumption under real life conditions in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Geppert, Jasmin

    2011-05-23

    In recent decades, energy and resource savings have become increasingly important, not only in the industrial, but also the residential sector. As one of the largest energy users in private homes, domestic refrigerators and freezers were among the first appliances to be targeted for energy efficiency improvements. With the aim of encouraging manufacturers to develop and produce more efficient appliances, the European Energy Label was introduced in the mid-nineties. However, the energy use of refrigerators does not only depend on technical components and features. Especially the using conditions in private homes are of a decisive influence. Thus, the present study has been conducted to test the sensitivity of refrigerators' energy consumption to various usage conditions within realistic ranges, which have been determined by means of two empirical studies. Key information gathered from the experiments were used as a base for the development and validation of a simplified model that allows predicting the energy consumption of refrigerators in use. The practical experiments were performed under controlled laboratory conditions with four different refrigerators with an A{sup +} or A{sup ++} energy efficiency rating (two statically cooled built-in fridge-freezers, one dynamically cooled refrigerator and one statically cooled refrigerator). The investigations revealed that the ambient temperature has the greatest impact on a refrigerator's energy consumption, followed by thermostat setting and heat load by insertion of warm items. The refrigerators' load under static conditions as well as the number of door openings have almost no impact on energy consumption. The modelling methodology follows a first-principle approach adjusted by experimental data. When compared to experimental results, model predictions show a reasonable agreement for the whole range of investigated conditions. (orig.)

  7. Operating conditions of batteries in off-grid renewable energy systems

    DEFF Research Database (Denmark)

    Svoboda, V.; Wenzl, H.; Kaiser, R.

    2007-01-01

    for batteries. Categories are defined in such a way that batteries belonging to the same category are subjected to similar operating conditions and a similar combination of stress factors. The results provide a comprehensive overview of battery operating conditions in existing off-grid renewable energy systems...

  8. Wood energy for residential heating in Alaska: current conditions, attitudes, and expected use

    Science.gov (United States)

    David L. Nicholls; Allen M. Brackley; Valerie. Barber

    2010-01-01

    This study considered three aspects of residential wood energy use in Alaska: current conditions and fuel consumption, knowledge and attitudes, and future use and conditions. We found that heating oil was the primary fuel for home heating in southeast and interior Alaska, whereas natural gas was used most often in south-central Alaska (Anchorage). Firewood heating...

  9. Casimir energy in d-dimensional rectangular geometries, under mixed boundary conditions

    International Nuclear Information System (INIS)

    Silva, J.C. da; Placido, Hebe Q.; Santana, A.E.; M Neto, Arthur

    1997-01-01

    The Casimir energy and its temperature corrections are presented for the electromagnetic field confined in a d-dimensional hypercavity. The expressions are derived considering Dirichlet boundary conditions for each pair of hyperplanes defining a confined direction (the homogeneous case); or yet, by choosing different boundary conditions (Dirichlet or Neumann) at each hyperplane of the pair (the mixed case). (author)

  10. Introduction condition of a tokamak fusion power plant as an advanced technology in world energy scenario

    International Nuclear Information System (INIS)

    Hiwatari, R.; Tokimatsu, K.; Asaoka, Y.; Okano, K.; Konishi, S.; Ogawa, Y.

    2005-01-01

    The present study reveals the following two introduction conditions of a tokamak fusion power plant in a long term world energy scenario. The first condition is the electric breakeven condition, which is required for the fusion energy to be recognized as a suitable candidate of an alternative energy source in the long term world energy scenario. As for the plasma performance (normalized beta value β N , confinement improvement factor for H-mode HH, the ratio of plasma density to Greenwald density limit fn GW ), the electric breakeven condition requires the simultaneous achievement of 1.2 N GW tmax =16 T, thermal efficiency η e =30%, and current drive power P NBI N ∼1.8, HH∼1.0, and fn GW ∼0.9, which correspond to the ITER reference operation parameters, have a strong potential to achieve the electric breakeven condition. The second condition is the economic breakeven condition, which is required to be selected as an alternative energy source. By using a long term world energy and environment model, the potential of the fusion energy in the long term world energy scenario is being investigated. Under the constraint of 550 ppm CO 2 concentration in the atmosphere, a breakeven price for introduction of the fusion energy in the year 2050 is estimated from 65mill/kWh to 135mill/kWh, which is considered as the economic breakeven condition in the present study. Under the conditions of B tmax =16T, η e =40%, plant availability 60%, and a radial build with/without CS coil, the economic breakeven condition requires β N ∼2.5 for 135mill/kWh of higher breakeven price case and β N ∼6.0 for 65mill/kWh of lower breakeven price case. Finally, the demonstration of steady state operation with β N ∼3.0 in the ITER project leads to the prospect to achieve the upper region of breakeven price in the world energy scenario. (author)

  11. Waste to energy plant operation under the influence of market and legislation conditioned changes

    DEFF Research Database (Denmark)

    Tomic, Tihomir; Dominkovic, Dominik Franjo; Pfeifer, Antun

    2017-01-01

    , waste-to-energy plants need to be adapted to market operation. This influence is tracked by the gate-fee volatility. The operation of the waste-to-energy plant on electricity markets is simulated by using EnergyPLAN and heat market is simulated in Matlab, based on hourly marginal costs. The results have......In this paper, gate-fee changes of the waste-to-energy plants are investigated in the conditions set by European Union legislation and by the introduction of the new heat market. Waste management and sustainable energy supply are core issues of sustainable development of regions, especially urban...... areas. These two energy flows logically come together in the combined heat and power facility by waste incineration. However, the implementation of new legislation influences quantity and quality of municipal waste and operation of waste-to-energy systems. Once the legislation requirements are met...

  12. Analysis of wind energy generation possibilities with various rotor types at disadvantageous wind condition zones

    Science.gov (United States)

    Bieniek, Andrzej

    2017-10-01

    The paper describe possibilities of energy generation using various rotor types but especially with multi-blade wind engine operates in the areas with unfavourable wind condition. The paper presents also wind energy conversion estimation results presented based on proposed solution of multi-blade wind turbine of outer diameter of 4 m. Based on the wind distribution histogram from the disadvantage wind condition zones (city of Basel) and taking into account design and estimated operating indexes of the considered wind engine rotor an annual energy generation was estimated. Also theoretical energy generation using various types of wind turbines operates at disadvantage wind conditions zones were estimated and compared. The conducted analysis shows that introduction of multi-blade wind rotor instead of the most popular 3- blades or vertical axis rotors results of about 5% better energy generation. Simultaneously there are energy production also at very disadvantages wind condition at wind speed lower then 4 m s-1. Based on considered construction of multi-blade wind engine the rise of rotor mounting height from 10 to 30 m results with more then 300 % better results in terms of electric energy generation.

  13. Analysis of wind energy generation possibilities with various rotor types at disadvantageous wind condition zones

    Directory of Open Access Journals (Sweden)

    Bieniek Andrzej

    2017-01-01

    Full Text Available The paper describe possibilities of energy generation using various rotor types but especially with multi-blade wind engine operates in the areas with unfavourable wind condition. The paper presents also wind energy conversion estimation results presented based on proposed solution of multi-blade wind turbine of outer diameter of 4 m. Based on the wind distribution histogram from the disadvantage wind condition zones (city of Basel and taking into account design and estimated operating indexes of the considered wind engine rotor an annual energy generation was estimated. Also theoretical energy generation using various types of wind turbines operates at disadvantage wind conditions zones were estimated and compared. The conducted analysis shows that introduction of multi-blade wind rotor instead of the most popular 3- blades or vertical axis rotors results of about 5% better energy generation. Simultaneously there are energy production also at very disadvantages wind condition at wind speed lower then 4 ms-1. Based on considered construction of multi-blade wind engine the rise of rotor mounting height from 10 to 30 m results with more then 300 % better results in terms of electric energy generation.

  14. A point-wise fiber Bragg grating displacement sensing system and its application for active vibration suppression of a smart cantilever beam subjected to multiple impact loadings

    International Nuclear Information System (INIS)

    Chuang, Kuo-Chih; Ma, Chien-Ching; Liao, Heng-Tseng

    2012-01-01

    In this work, active vibration suppression of a smart cantilever beam subjected to disturbances from multiple impact loadings is investigated with a point-wise fiber Bragg grating (FBG) displacement sensing system. An FBG demodulator is employed in the proposed fiber sensing system to dynamically demodulate the responses obtained by the FBG displacement sensor with high sensitivity. To investigate the ability of the proposed FBG displacement sensor as a feedback sensor, velocity feedback control and delay control are employed to suppress the vibrations of the first three bending modes of the smart cantilever beam. To improve the control performance for the first bending mode when the cantilever beam is subjected to an impact loading, we improve the conventional velocity feedback controller by tuning the control gain online with the aid of information from a higher vibration mode. Finally, active control of vibrations induced by multiple impact loadings due to a plastic ball is performed with the improved velocity feedback control. The experimental results show that active vibration control of smart structures subjected to disturbances such as impact loadings can be achieved by employing the proposed FBG sensing system to feed back out-of-plane point-wise displacement responses with high sensitivity. (paper)

  15. Greenbelt Homes Pilot Energy Efficiency Program Phase 1 Summary. Existing Conditions and Baseline Energy Use

    Energy Technology Data Exchange (ETDEWEB)

    Wiehagen, J. [NAHB Research Center, Upper Marlboro, MD (United States); Del Bianco, M. [NAHB Research Center, Upper Marlboro, MD (United States); Wood, A. [NAHB Research Center, Upper Marlboro, MD (United States)

    2013-02-01

    A multi-year pilot energy efficiency retrofit project has been undertaken by Greenbelt Homes, Inc, (GHI) a 1,566 co-operative of circa 1930 and '40 homes. The three predominate construction methods of the townhomes in the community are materials common to the area and climate zone including 8” CMU block, wood frame with brick veneer and wood frame with vinyl siding. GHI has established a pilot project that will serve as a basis for decision making for the roll out of a decade-long community upgrade program that will incorporate energy efficiency to the building envelope and equipment with the modernization of other systems like plumbing, mechanical equipment, and cladding.

  16. Greenbelt Homes Pilot Energy Efficiency Program Phase 1 Summary: Existing Conditions and Baseline Energy Use

    Energy Technology Data Exchange (ETDEWEB)

    Wiehagen, J.; Del Bianco, M.; Wood, A.

    2013-02-01

    A multi-year pilot energy efficiency retrofit project has been undertaken by Greenbelt Homes, Inc, (GHI) a 1,566 co-operative of circa 1930 and '40 homes. The three predominate construction methods of the townhomes in the community are materials common to the area and climate zone including 8" CMU block, wood frame with brick veneer and wood frame with vinyl siding. GHI has established a pilot project that will serve as a basis for decision making for the roll out of a decade-long community upgrade program that will incorporate energy efficiency to the building envelope and equipment with the modernization of other systems like plumbing, mechanical equipment, and cladding.

  17. Energy and Greenhouse Gas Emission Assessment of Conventional and Solar Assisted Air Conditioning Systems

    Directory of Open Access Journals (Sweden)

    Xiaofeng Li

    2015-11-01

    Full Text Available Energy consumption in the buildings is responsible for 26% of Australia’s greenhouse gas emissions where cooling typically accounts for over 50% of the total building energy use. The aim of this study was to investigate the potential for reducing the cooling systems’ environmental footprint with applications of alternative renewable energy source. Three types of cooling systems, water cooled, air cooled and a hybrid solar-based air-conditioning system, with a total of six scenarios were designed in this work. The scenarios accounted for the types of power supply to the air-conditioning systems with electricity from the grid and with a solar power from highly integrated building photovoltaics (BIPV. Within and between these scenarios, systems’ energy performances were compared based on energy modelling while the harvesting potential of the renewable energy source was further predicted based on building’s detailed geometrical model. The results showed that renewable energy obtained via BIPV scenario could cover building’s annual electricity consumption for cooling and reduce 140 tonnes of greenhouse gas emissions each year. The hybrid solar air-conditioning system has higher energy efficiency than the air cooled chiller system but lower than the water cooled system.

  18. Methods for locating ground faults and insulation degradation condition in energy conversion systems

    Science.gov (United States)

    Agamy, Mohamed; Elasser, Ahmed; Galbraith, Anthony William; Harfman Todorovic, Maja

    2015-08-11

    Methods for determining a ground fault or insulation degradation condition within energy conversion systems are described. A method for determining a ground fault within an energy conversion system may include, in part, a comparison of baseline waveform of differential current to a waveform of differential current during operation for a plurality of DC current carrying conductors in an energy conversion system. A method for determining insulation degradation within an energy conversion system may include, in part, a comparison of baseline frequency spectra of differential current to a frequency spectra of differential current transient at start-up for a plurality of DC current carrying conductors in an energy conversion system. In one embodiment, the energy conversion system may be a photovoltaic system.

  19. Energy-Efficient Supermarket Heating, Ventilation, and Air Conditioning in Humid Climates in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Clark, J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-03-01

    Supermarkets are energy-intensive buildings that consume the greatest amount of electricity per square foot of building of any building type in the United States and represent 5% of total U.S. commercial building primary energy use (EIA 2005). Refrigeration and heating, ventilation, and air-conditioning (HVAC) systems are responsible for a large proportion of supermarkets’ total energy use. These two systems sometimes work together and sometimes compete, but the performance of one system always affects the performance of the other. To better understand these challenges and opportunities, the Commercial Buildings team at the National Renewable Energy Laboratory investigated several of the most promising strategies for providing energy-efficient HVAC for supermarkets and quantified the resulting energy use and costs using detailed simulations. This research effort was conducted on behalf of the U.S. Department of Energy (DOE) Commercial Building Partnerships (CBP) (Baechler et al. 2012; Parrish et al. 2013; Antonopoulos et al. 2014; Hirsch et al. 2014). The goal of CBP was to reduce energy use in the commercial building sector by creating, testing, and validating design concepts on the pathway to net zero energy commercial buildings. Several CBP partners owned or operated buildings containing supermarkets and were interested in optimizing the energy efficiency of supermarket HVAC systems in hot-humid climates. These partners included Walmart, Target, Whole Foods Market, SUPERVALU, and the Defense Commissary Agency.

  20. Energy Performance and Optimal Control of Air-conditioned Buildings Integrated with Phase Change Materials

    Science.gov (United States)

    Zhu, Na

    This thesis presents an overview of the previous research work on dynamic characteristics and energy performance of buildings due to the integration of PCMs. The research work on dynamic characteristics and energy performance of buildings using PCMs both with and without air-conditioning is reviewed. Since the particular interest in using PCMs for free cooling and peak load shifting, specific research efforts on both subjects are reviewed separately. A simplified physical dynamic model of building structures integrated with SSPCM (shaped-stabilized phase change material) is developed and validated in this study. The simplified physical model represents the wall by 3 resistances and 2 capacitances and the PCM layer by 4 resistances and 2 capacitances respectively while the key issue is the parameter identification of the model. This thesis also presents the studies on the thermodynamic characteristics of buildings enhanced by PCM and on the investigation of the impacts of PCM on the building cooling load and peak cooling demand at different climates and seasons as well as the optimal operation and control strategies to reduce the energy consumption and energy cost by reducing the air-conditioning energy consumption and peak load. An office building floor with typical variable air volume (VAV) air-conditioning system is used and simulated as the reference building in the comparison study. The envelopes of the studied building are further enhanced by integrating the PCM layers. The building system is tested in two selected cities of typical climates in China including Hong Kong and Beijing. The cold charge and discharge processes, the operation and control strategies of night ventilation and the air temperature set-point reset strategy for minimizing the energy consumption and electricity cost are studied. This thesis presents the simulation test platform, the test results on the cold storage and discharge processes, the air-conditioning energy consumption and demand

  1. Design and Realization of a Condition Management System for the Gateway Electrical Energy Metering Device

    Directory of Open Access Journals (Sweden)

    Chao Tang

    2013-12-01

    Full Text Available With the construction of firm and intelligent power grid in China, it is difficult for the traditional management method of electrical energy metering device to meet the prospecting requirements. Using the computer and internet techniques to realize the information and intelligentization of the electrical energy metering management has become a necessary guarantee of improving power supply ability, marketing control, and customer service. This paper introduced a kind of large and intelligent condition management system of the gateway electrical energy metering device. The key technologies and realize process were analyzed. Moreover, a detailed description of the application modules such as the GIS smart display of metering point, the condition management of metering devices and the visual monitoring of metering point was presented. The trial operation in the selected transformer substations and the power stations of Chongqing Power Electrical Corp. indicated that, the condition management system is very open, safety and efficient. According to the data exchange with the production and scheduling platform, the system improved the efficient operation of the electrical energy metering devices. Meanwhile, combined with the real-time visual monitoring, the condition management system improved the prevention ability of electricity filching, realized the unified automatic large-scale management of electrical energy metering devices.

  2. Intelligent energy management control of vehicle air conditioning system coupled with engine

    International Nuclear Information System (INIS)

    Khayyam, Hamid; Abawajy, Jemal; Jazar, Reza N.

    2012-01-01

    Vehicle Air Conditioning (AC) systems consist of an engine powered compressor activated by an electrical clutch. The AC system imposes an extra load to the vehicle's engine increasing the vehicle fuel consumption and emissions. Energy management control of the vehicle air conditioning is a nonlinear dynamic system, influenced by uncertain disturbances. In addition, the vehicle energy management control system interacts with different complex systems, such as engine, air conditioning system, environment, and driver, to deliver fuel consumption improvements. In this paper, we describe the energy management control of vehicle AC system coupled with vehicle engine through an intelligent control design. The Intelligent Energy Management Control (IEMC) system presented in this paper includes an intelligent algorithm which uses five exterior units and three integrated fuzzy controllers to produce desirable internal temperature and air quality, improved fuel consumption, low emission, and smooth driving. The three fuzzy controllers include: (i) a fuzzy cruise controller to adapt vehicle cruise speed via prediction of the road ahead using a Look-Ahead system, (ii) a fuzzy air conditioning controller to produce desirable temperature and air quality inside vehicle cabin room via a road information system, and (iii) a fuzzy engine controller to generate the required engine torque to move the vehicle smoothly on the road. We optimised the integrated operation of the air conditioning and the engine under various driving patterns and performed three simulations. Results show that the proposed IEMC system developed based on Fuzzy Air Conditioning Controller with Look-Ahead (FAC-LA) method is a more efficient controller for vehicle air conditioning system than the previously developed Coordinated Energy Management Systems (CEMS). - Highlights: ► AC interacts: vehicle, environment, driver components, and the interrelationships between them. ► Intelligent AC algorithm which uses

  3. Operation of a wind turbine-flywheel energy storage system under conditions of stochastic change of wind energy.

    Science.gov (United States)

    Tomczewski, Andrzej

    2014-01-01

    The paper presents the issues of a wind turbine-flywheel energy storage system (WT-FESS) operation under real conditions. Stochastic changes of wind energy in time cause significant fluctuations of the system output power and as a result have a negative impact on the quality of the generated electrical energy. In the author's opinion it is possible to reduce the aforementioned effects by using an energy storage of an appropriate type and capacity. It was assumed that based on the technical parameters of a wind turbine-energy storage system and its geographical location one can determine the boundary capacity of the storage, which helps prevent power cuts to the grid at the assumed probability. Flywheel energy storage was selected due to its characteristics and technical parameters. The storage capacity was determined based on an empirical relationship using the results of the proposed statistical and energetic analysis of the measured wind velocity courses. A detailed algorithm of the WT-FESS with the power grid system was developed, eliminating short-term breaks in the turbine operation and periods when the wind turbine power was below the assumed level.

  4. The effect of poling conditions on the performance of piezoelectric energy harvesters fabricated by wet chemistry

    KAUST Repository

    Fuentes-Fernandez, Erika Maria-Anai

    2015-03-25

    The effect of poling conditions on the power output of piezoelectric energy harvesters using sol-gel based Pb(Zr0.53,Ti0.47)O3-Pb(Zn1/3,Nb2/3)O3 piezoelectric thin-films has been investigated. A strong correlation was established between the poling efficiency and harvester output. A method based on simple capacitance-voltage measurements is shown to be an effective approach to estimate the power output of harvesters poled under different conditions. The poling process was found to be thermally activated with an activation energy of 0.12 eV, and the optimum poling conditions were identified (200 kV cm-1, 250 °C for 50 min). The voltage output and power density obtained under optimum poling conditions were measured to be 558 V cm-2 and 325 μW cm-2, respectively. © The Royal Society of Chemistry.2015.

  5. Assessment of monitored energy use and thermal comfort conditions in mosques in hot-humid climates

    Energy Technology Data Exchange (ETDEWEB)

    Al-Homoud, Mohammad S.; Abdou, Adel A.; Budaiwi, Ismail M. [Architectural Engineering Department, KFUPM, Dhahran 31261 (Saudi Arabia)

    2009-06-15

    In harsh climatic regions, buildings require air-conditioning in order to provide an acceptable level of thermal comfort. In many situations buildings are over cooled or the HVAC system is kept running for a much longer time than needed. In some other situations thermal comfort is not achieved due to improper operation practices coupled with poor maintenance and even lack it, and consequently inefficient air-conditioning systems. Mosques represent one type of building that is characterized by their unique intermittent operating schedule determined by prayer times, which vary continuously according to the local solar time. This paper presents the results of a study designed to monitor energy use and thermal comfort conditions of a number of mosques in a hot-humid climate so that both energy efficiency and the quality of thermal comfort conditions especially during occupancy periods in such intermittently operated buildings can be assessed accurately. (author)

  6. Energy efficient hybrid nanocomposite-based cool thermal storage air conditioning system for sustainable buildings

    International Nuclear Information System (INIS)

    Parameshwaran, R.; Kalaiselvam, S.

    2013-01-01

    The quest towards energy conservative building design is increasingly popular in recent years, which has triggered greater interests in developing energy efficient systems for space cooling in buildings. In this work, energy efficient silver–titania HiTES (hybrid nanocomposites-based cool thermal energy storage) system combined with building A/C (air conditioning) system was experimentally investigated for summer and winter design conditions. HiNPCM (hybrid nanocomposite particles embedded PCM) used as the heat storage material has exhibited 7.3–58.4% of improved thermal conductivity than at its purest state. The complete freezing time for HiNPCM was reduced by 15% which was attributed to its improved thermophysical characteristics. Experimental results suggest that the effective energy redistribution capability of HiTES system has contributed for reduction in the chiller nominal cooling capacity by 46.3% and 39.6% respectively, under part load and on-peak load operating conditions. The HiTES A/C system achieved 27.3% and 32.5% of on-peak energy savings potential in summer and winter respectively compared to the conventional A/C system. For the same operating conditions, this system yield 8.3%, 12.2% and 7.2% and 10.2% of per day average and yearly energy conservation respectively. This system can be applied for year-round space conditioning application without sacrificing energy efficiency in buildings. - Highlights: • Energy storage is acquired by HiTES (hybrid nanocomposites-thermal storage) system. • Thermal conductivity of HiNPCM (hybrid nanocomposites-PCM) was improved by 58.4%. • Freezing time of HiNPCM was reduced by 15% that enabled improved energy efficiency. • Chiller nominal capacity was reduced by 46.3% and 39.6% in on-peak and part load respectively. • HiTES A/C system achieved appreciable energy savings in the range of 8.3–12.2%

  7. Energy Saving Potential of PCMs in Buildings under Future Climate Conditions

    Directory of Open Access Journals (Sweden)

    Abdo Abdullah Ahmed Gassar

    2017-11-01

    Full Text Available Energy consumption reduction under changing climate conditions is a major challenge in buildings design, where excessive energy consumption creates an economic and environmental burden. Improving thermal performance of the buildings through support applying phase change material (PCM is a promising strategy for reducing building energy consumption under future climate change. Therefore, this study aims to investigate the energy saving potentials in buildings under future climate conditions in the humid and snowy regions in the hot continental and humid subtropical climates of the east Asia (Seoul, Tokyo and Hong Kong when various PCMs with different phase change temperatures are applied to a lightweight building envelope. Methodology in this work is implemented in two phases: firstly, investigation of energy saving potentials in buildings through inclusion of three types of PCMs with different phase temperatures into the building envelop separately and use weather file in the present (2017; and, secondly, evaluation of the effect of future climate change on the performance of PCMs by analyzing energy saving potentials of PCMs with 2020, 2050 and 2080 weather data. The results show that the inclusion of PCM into the building envelope is a promising strategy to increase the energy performance in buildings during both heating and cooling seasons in Seoul, Tokyo and Hong Kong under future climate conditions. The energy savings achieved by using PCMs in those regions are electricity savings of 4.48–8.21%, 3.81–9.69%, and 1.94–5.15%, and gas savings of 1.65–16.59%, 7.60–61.76%, and 62.07–93.33% in Seoul, Tokyo and Hong Kong, respectively, for the years 2017, 2020, 2050 and 2080. In addition, BioPCM and RUBITHERMPCM are the most efficient for improving thermal performance and saving energy in buildings in the tested regions and years.

  8. Influence of Urban Microclimate on Air-Conditioning Energy Needs and Indoor Thermal Comfort in Houses

    Directory of Open Access Journals (Sweden)

    Feng-Chi Liao

    2015-01-01

    Full Text Available A long-term climate measurement was implemented in the third largest city of Taiwan, for the check of accuracy of morphing approach on generating the hourly data of urban local climate. Based on observed and morphed meteorological data, building energy simulation software EnergyPlus was used to simulate the cooling energy consumption of an air-conditioned typical flat and the thermal comfort level of a naturally ventilated typical flat. The simulated results were used to quantitatively discuss the effect of urban microclimate on the energy consumption as well as thermal comfort of residential buildings. The findings of this study can serve as a reference for city planning and energy management divisions to study urban sustainability strategies in the future.

  9. Boundary conditions, energies and gravitational heat in general relativity (a classical analysis)

    International Nuclear Information System (INIS)

    Francaviglia, M; Raiteri, M

    2004-01-01

    The variation of the energy for a gravitational system is directly defined from the Hamiltonian field equations of general relativity. When the variation of the energy is written in a covariant form, it splits into two (covariant) contributions: one of them is the Komar energy, while the other is the so-called covariant ADM correction term. When specific boundary conditions are analysed one sees that the Komar energy is related to the gravitational heat while the ADM correction term plays the role of the Helmholtz free energy. These properties allow one to establish, inside a classical geometric framework, a formal analogy between gravitation and the laws governing the evolution of a thermodynamical system. The analogy applies to stationary spacetimes admitting multiple causal horizons as well as to AdS Taub-bolt solutions

  10. Effects of machining conditions on the specific cutting energy of carbon fibre reinforced polymer composites

    Science.gov (United States)

    Azmi, A. I.; Syahmi, A. Z.; Naquib, M.; Lih, T. C.; Mansor, A. F.; Khalil, A. N. M.

    2017-10-01

    This article presents an approach to evaluate the effects of different machining conditions on the specific cutting energy of carbon fibre reinforced polymer composites (CFRP). Although research works in the machinability of CFRP composites have been very substantial, the present literature rarely discussed the topic of energy consumption and the specific cutting energy. A series of turning experiments were carried out on two different CFRP composites in order to determine the power and specific energy constants and eventually evaluate their effects due to the changes in machining conditions. A good agreement between the power and material removal rate using a simple linear relationship. Further analyses revealed that a power law function is best to describe the effect of feed rate on the changes in the specific cutting energy. At lower feed rate, the specific cutting energy increases exponentially due to the nature of finishing operation, whereas at higher feed rate, the changes in specific cutting energy is minimal due to the nature of roughing operation.

  11. Contribution of air conditioning adoption to future energy use under global warming

    Science.gov (United States)

    Davis, Lucas W.; Gertler, Paul J.

    2015-01-01

    As household incomes rise around the world and global temperatures go up, the use of air conditioning is poised to increase dramatically. Air conditioning growth is expected to be particularly strong in middle-income countries, but direct empirical evidence is scarce. In this paper we use high-quality microdata from Mexico to describe the relationship between temperature, income, and air conditioning. We describe both how electricity consumption increases with temperature given current levels of air conditioning, and how climate and income drive air conditioning adoption decisions. We then combine these estimates with predicted end-of-century temperature changes to forecast future energy consumption. Under conservative assumptions about household income, our model predicts near-universal saturation of air conditioning in all warm areas within just a few decades. Temperature increases contribute to this surge in adoption, but income growth by itself explains most of the increase. What this will mean for electricity consumption and carbon dioxide emissions depends on the pace of technological change. Continued advances in energy efficiency or the development of new cooling technologies could reduce the energy consumption impacts. Similarly, growth in low-carbon electricity generation could mitigate the increases in carbon dioxide emissions. However, the paper illustrates the enormous potential impacts in this sector, highlighting the importance of future research on adaptation and underscoring the urgent need for global action on climate change. PMID:25918391

  12. Contribution of air conditioning adoption to future energy use under global warming.

    Science.gov (United States)

    Davis, Lucas W; Gertler, Paul J

    2015-05-12

    As household incomes rise around the world and global temperatures go up, the use of air conditioning is poised to increase dramatically. Air conditioning growth is expected to be particularly strong in middle-income countries, but direct empirical evidence is scarce. In this paper we use high-quality microdata from Mexico to describe the relationship between temperature, income, and air conditioning. We describe both how electricity consumption increases with temperature given current levels of air conditioning, and how climate and income drive air conditioning adoption decisions. We then combine these estimates with predicted end-of-century temperature changes to forecast future energy consumption. Under conservative assumptions about household income, our model predicts near-universal saturation of air conditioning in all warm areas within just a few decades. Temperature increases contribute to this surge in adoption, but income growth by itself explains most of the increase. What this will mean for electricity consumption and carbon dioxide emissions depends on the pace of technological change. Continued advances in energy efficiency or the development of new cooling technologies could reduce the energy consumption impacts. Similarly, growth in low-carbon electricity generation could mitigate the increases in carbon dioxide emissions. However, the paper illustrates the enormous potential impacts in this sector, highlighting the importance of future research on adaptation and underscoring the urgent need for global action on climate change.

  13. The role of energy planners in open-free market conditions

    International Nuclear Information System (INIS)

    Alminana, D. G.

    2003-01-01

    The evolution of the demand for electricity and natural gas usually follows seasonal patterns. In Mediterranean areas, in summer, a sharp increase in electricity needs in residential and commercial buildings coincides with a marked decrease in natural gas consumption. Air-conditioning systems are an increasingly significant factor in peak electricity demand in premises of all economic areas, particularly residential and commercial but also industrial sectors. Efforts made in recent years regarding the development of low cost air-conditioning equipment have produced in turn an increasing number of shortages due to lack of capacity in the production-transmission-distribution chain. Recent examples in Barcelona (June 2003) or Mallorca (July 2003) are just a reference for an ever-increasing problem. In open-free market conditions, how can this situation be overcome? Energy suppliers adopt strategies of Demand Side Management (DSM) in order to reduce negative impact of load curves which are not 'flat enough'. However, negative impacts are mainly seen in terms of economic operation, ignoring other effects such as energy or environmental collateral effects. From our point of view, Integrated Resources Planning (IRP) is a more powerful tool to take into account all three effects: economic, energy and environmental. IRP cannot be carried out by single energy suppliers, only by an Energy Planner. Two specific technologies can help balance energy loads from excess power demand (peak shaving) and reduced gas consumption (valley filling) in summer: High Efficiency Cogeneration / Trigeneration; High Efficiency Gas-Based Air-Conditioning. Recent COM(2003)416 final Directive 'on the promotion of cogeneration based on a useful heat demand in the internal energy market' (Brussels, July 23, 2003) can be adopted as a confirmation of the above issues. (author)

  14. The effect of poling conditions on the performance of piezoelectric energy harvesters fabricated by wet chemistry

    KAUST Repository

    Fuentes-Fernandez, Erika Maria-Anai; Gnade, Bruce E; Quevedo-Ló pez, Manuel Angel; Shah, Pradeep; Alshareef, Husam N.

    2015-01-01

    The effect of poling conditions on the power output of piezoelectric energy harvesters using sol-gel based Pb(Zr0.53,Ti0.47)O3-Pb(Zn1/3,Nb2/3)O3 piezoelectric thin-films has been investigated. A strong correlation was established between the poling

  15. Use of solar energy for heat supply under conditions of the Socialist Federated Republic of Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    Savic, B.

    1981-01-01

    The characteristics of a flat solar energy collector are used to determine the specific heat productivity of the solar unit under meteorological conditions of Belgrade. The evaluation is made with regard for experimental data of year-round operation of hot water supply units and the seasonal use of heating units.

  16. Energy Management Strategy for Hybrid Electric Vehicle Based on Driving Condition Identification Using KGA-Means

    Directory of Open Access Journals (Sweden)

    Shuxian Li

    2018-06-01

    Full Text Available In order to solve the problem related to adaptive energy management strategies based on driving condition identification being difficult to be applied to a real hybrid electric vehicle (HEV controller, this paper proposes an energy management strategy by combining the driving condition identification algorithm based on genetic optimized K-means clustering algorithm (KGA-means, and the equivalent consumption minimization strategy (ECMS. The simulation results show that compared with ECMS, the energy management strategy proposed in this article drives the engine working point closer to the best efficiency curve, and smooths out the state of charge (SOC change and better maintains the SOC in a highly efficient area. As a result, the vehicle fuel consumption reduces by 6.84%.

  17. The Analysis of the Chosen Internal Condition and Prospects of Romania’s Energy Security

    Directory of Open Access Journals (Sweden)

    Rutka Michał

    2017-03-01

    Full Text Available In the age of high pace of technological, economic and social development, stable and uninterrupted energy supply is one of the key components determining the economic sovereignty of the state, its position in international relations, and the quality of human life. Every economy around the world is heavily dependent on its energy sector. Consequently, ensuring energy security is currently one of the most important determinant of every country’s national security and the purpose of its security policy. In this article we focus on Romania’s energy security internal condition and prospects. Our main goal is to present actual state and prospects of Romanian energy sector. In order to achieve that goal, we decided to use various methods, such as descriptive analysis, document analysis and comparative analysis. The article has two parts. The first part consists of a description of energy sources and infrastructure used by Romanian economy. The second part is an analysis of possible chances and threats for both energy sector and energy security level.

  18. Analyzing energy consumption while heating one-layer building envelopes in conditions of intermittent heating

    Directory of Open Access Journals (Sweden)

    Vytchikov Yury

    2017-01-01

    Full Text Available This paper focuses on energy consumption for heating single layer building envelopes, used in conditions of intermittent heating in different physical and mechanical and thermophysical parameters of construction materials. The authors investigated several variants of single-layer building envelopes, used frequently in building practice, with different density and coefficients of building materials thermal conductivity. For each variant of a building envelope heat leakage and time spent on heating were calculated. Heating time was calculated by both exact and approximate analytical method. Then the researchers draw a graphic dependence of energy consumption on the density of the material taking this computational data as a basis. Further analysis showed that building envelopes made of lightweight aggregate concrete and porous concrete were the most energy efficient.This paper focuses on energy consumption for heating single layer building envelopes, used in conditions of intermittent heating in different physical and mechanical and thermophysical parameters of construction materials. The authors investigated several variants of single-layer building envelopes, used frequently in building practice, with different density and coefficients of building materials thermal conductivity. For each variant of a building envelope heat leakage and time spent on heating were calculated. Heating time was calculated by both exact and approximate analytical method. Then the researchers draw a graphic dependence of energy consumption on the density of the material taking this computational data as a basis. Further analysis showed that building envelopes made of lightweight aggregate concrete and porous concrete were the most energy efficient.

  19. An energy impact assessment of indoor air quality acceptance for air-conditioned offices

    International Nuclear Information System (INIS)

    Wong, L.T.; Mui, K.W.; Shi, K.L.; Hui, P.S.

    2008-01-01

    Treatment of fresh air in ventilation systems for the air-conditioning consumes a considerable amount of energy and affects the indoor air quality (IAQ). The ventilation demand is primarily related to the occupant load. In this study, the ventilation demands due to occupant load variations and occupant acceptability were examined against certain IAQ objectives using the mass balance of carbon dioxide (CO 2 ) concentrations in an air-conditioned office. In particular, this study proposed a ventilation model for the consideration of the occupant load variations and occupant acceptability based on the regional survey of typical offices (422 samples) in Hong Kong. The model was applied to evaluate the relative energy performance of different IAQ objectives in ventilation systems for typical office buildings in Hong Kong. The results showed that the energy consumption of a ventilation system would be correlated with the occupant load and acceptability in the air-conditioned office. Indicative CO 2 levels of 800 ppmv, 1000 ppmv and 1200 ppmv corresponding to 83%, 97% and 99.7% survey samples were shown, corresponding to the thermal energy consumptions of 1500 MJ m -2 yr -1 , 960 MJ m -2 yr -1 and 670 MJ m -2 yr -1 , respectively. In regards to the monetary issue, an annual value of HK$ 762 million per year in electrical consumption could be saved in all office buildings in Hong Kong when the indoor target CO 2 concentration is increased from 1000 ppmv to 1200 ppmv. To achieve an excellent IAQ following the existing design standard, i.e. to decrease the CO 2 level from 1000 ppmv to 800 ppmv, 56% additional energy would be consumed, corresponding to an annual value of HK$ 1,419 million, even though the occupant acceptability is only improved from 81% to 86%. The development of the models in this study would be useful for the energy performance evaluation of ventilation systems in air-conditioned offices

  20. Thermal and Energy Performance of Conditioned Building Due To Insulated Sloped Roof

    Science.gov (United States)

    Irwan, Suhandi Syiful; Ahmed, Azni Zain; Zakaria, Nor Zaini; Ibrahim, Norhati

    2010-07-01

    For low-rise buildings in equatorial region, the roof is exposed to solar radiation longer than other parts of the envelope. Roofs are to be designed to reject heat and moderate the thermal impact. These are determined by the design and construction of the roofing system. The pitch of roof and the properties of construction affect the heat gain into the attic and subsequently the indoor temperature of the living spaces underneath. This finally influences the thermal comfort conditions of naturally ventilated buildings and cooling load of conditioned buildings. This study investigated the effect of insulated sloping roof on thermal energy performance of the building. A whole-building thermal energy computer simulation tool, Integrated Environmental Solution (IES), was used for the modelling and analyses. A building model with dimension of 4.0 m × 4.0 m × 3.0 m was designed with insulated roof and conventional construction for other parts of the envelope. A 75 mm conductive insulation material with thermal conductivity (k-value) of 0.034 Wm-1K-1 was installed underneath the roof tiles. The building was modelled with roof pitch angles of 0° , 15°, 30°, 45°, 60° and simulated for the month of August in Malaysian climate conditions. The profile for attic temperature, indoor temperature and cooling load were downloaded and evaluated. The optimum roof pitch angle for best thermal performance and energy saving was identified. The results show the pitch angle of 0° is able to mitigate the thermal impact to provide the best thermal condition with optimum energy savings. The maximum temperature difference between insulated and non-insulted roof for attic (AtticA-B) and indoor condition (IndoorA-B) is +7.8 °C and 0.4 °C respectively with an average energy monthly savings of 3.9 %.

  1. Case Study of a Nearly Zero Energy Building in Italian Climatic Conditions

    Directory of Open Access Journals (Sweden)

    Hassan Saeed Khan

    2017-11-01

    Full Text Available The building sector is an important stakeholder in the energy and environmental scenario of any country. It continues to grow across the world due to factors such as population growth, and economic and infrastructure development. Within the European Union, buildings account for 40% of the total energy requirements and 30% of carbon dioxide emissions. The building sector is keen to improve its sustainability standards and also to help achieve the 20-20-20 targets set by the European Union. The present work aims to design a nearly zero energy sports gymnasium building in Calolziocorte, Italy. Various sustainability techniques are applied in an integrated design project approach using ECOTECT software to undertake the energy modelling exercise. Firstly, the base-case is modelled with conventional building materials and the total energy demand is calculated. Duly considering the local climatic conditions, sustainable materials are chosen for walls, the floor, the roof, and windows and a 38% reduction is noted in the total energy demand of the building compared to the base-case. The impact of louvers as a passive design technique has also been examined on the total energy demand of the building. The monthly load/discomfort analysis is undertaken for various individual functions inside the building to identify the critical areas that consume more energy. The monthly load/discomfort analysis is performed with the proposed materials and the air infiltration rate is improved through the building envelope and 63% reduction is noted in the total energy demand of the building compared to the base-case. A solar access analysis is conducted to understand the on-site energy production and then the building net energy demand is calculated, which is reduced to 90% compared to the base-case.

  2. A study of energy use for ventilation and air-conditioning systems in Hong Kong

    Science.gov (United States)

    Yu, Chung Hoi Philip

    Most of the local modern buildings are high-rise with enclosed structure. Mechanical ventilation and air conditioning (MVAC) systems are installed for thermal comfort. Various types of MVAC systems found in Hong Kong were critically reviewed with comments on their characteristics in energy efficiency as well as application. The major design considerations were also discussed. Besides MVAC, other energy-consuming components in commercial buildings were also identified, such as lighting, lifts and escalators, office equipment, information technology facilities, etc. A practical approach has been adopted throughout this study in order that the end results will have pragmatic value to the heating, ventilating and air-conditioning (HVAC) industry in Hong Kong. Indoor Air Quality (IAQ) has become a major issue in commercial buildings worldwide including Hong Kong. Ventilation rate is no doubt a critical element in the design of HVAC systems, which can be realized more obviously in railway train compartments where the carbon dioxide level will be built up quickly when the compartments are crowded during rush hours. A study was carried out based on a simplified model using a train compartment that is equipped with an MVAC system. Overall Thermal Transfer Value (OTTV) is a single-value parameter for controlling building energy use and is relatively simple to implement legislatively. The local government has taken a first step in reacting to the worldwide concern of energy conservation and environmental protection since 1995. Different methods of OTTV calculation were studied and the computation results were compared. It gives a clear picture of the advantages and limitations for each method to the building designers. However, due to the limitations of using OTTV as the only parameter for building energy control, some new approaches to a total control of building energy use were discussed and they might be considered for future revision of the building energy codes in Hong

  3. Energy conservation and environmental protection policy in Poland under conditions of transition

    International Nuclear Information System (INIS)

    Kapala, J.

    2000-01-01

    Based on experience and many years of research in the field of energy use, ways of solving methodological problems of energy conservation and environmental protection in Poland have been proposed. These problems were examined as related to the conditions of centrally-planned to market economy, with due considerations for experience of highly developed countries. The paper also presents criteria and functions for qualification of the results of energy conservation and environment protection. It emphasises the importance of direct economical criteria and non-economical criteria when solving ecology-related problems. In this stage the proposals outlined in the paper have only a theoretical character. They could be developed further as the results of the research work in the field of energy conservation and ambient media (air, water, soil) protection are brought to a common denominator. (author)

  4. Foundations of high-energy-density physics physical processes of matter at extreme conditions

    CERN Document Server

    Larsen, Jon

    2017-01-01

    High-energy-density physics explores the dynamics of matter at extreme conditions. This encompasses temperatures and densities far greater than we experience on Earth. It applies to normal stars, exploding stars, active galaxies, and planetary interiors. High-energy-density matter is found on Earth in the explosion of nuclear weapons and in laboratories with high-powered lasers or pulsed-power machines. The physics explored in this book is the basis for large-scale simulation codes needed to interpret experimental results whether from astrophysical observations or laboratory-scale experiments. The key elements of high-energy-density physics covered are gas dynamics, ionization, thermal energy transport, and radiation transfer, intense electromagnetic waves, and their dynamical coupling. Implicit in this is a fundamental understanding of hydrodynamics, plasma physics, atomic physics, quantum mechanics, and electromagnetic theory. Beginning with a summary of the topics and exploring the major ones in depth, thi...

  5. Achieving better energy-efficient air conditioning – A review of technologies and strategies

    International Nuclear Information System (INIS)

    Chua, K.J.; Chou, S.K.; Yang, W.M.; Yan, J.

    2013-01-01

    Air conditioning is essential for maintaining thermal comfort in indoor environments, particularly for hot and humid climates. Today, air conditioning, comprising cooling and dehumidification, has become a necessity in commercial and residential buildings and industrial processes. It accounts for a major share of the energy consumption of a building or facility. In tropical climates, the energy consumed by heating, ventilation and air-conditioning (HVAC) can exceed 50% of the total energy consumption of a building. This significant figure is primarily due to the heavy duty placed on cooling technologies to remove both sensible and latent heat loads. Therefore, there is tremendous potential to improve the overall efficiency of the air-conditioning systems in buildings. Based on today’s practical technology for cooling, the major components of a chiller plant are (1) compressors, (2) cooling towers, (3) pumps (chilled and cooling water) and (4) fans in air handling units. They all consume mainly electricity to operate. When specifying the kW/R ton of a plant, there are two levels of monitoring cooling efficiency: (1) at the efficiency of the chiller machines or the compressors which consume a major amount of electricity; and (2) at the overall efficiency of cooling plants which include the cooling towers, pumps for moving coolant (chilled and cooling water) to all air-handling units. Pragmatically, a holistic approach is necessary towards achieving a low energy input per cooling achieved such as 0.6 kW/R ton cooling or lower by considering all aspects of the cooling plant. In this paper, we present a review of recent innovative cooling technology and strategies that could potentially lower the kW/R ton of cooling systems – from the existing mean of 0.9 kW/R ton towards 0.6 kW/R ton or lower. The paper, broadly divided into three key sections (see Fig. 2), begins with a review of the recent novel devices that enhances the energy efficiency of cooling systems at

  6. Energy crop (Sida hermaphrodita) fertilization using digestate under marginal soil conditions: A dose-response experiment

    Science.gov (United States)

    Nabel, Moritz; Bueno Piaz Barbosa, Daniela; Horsch, David; Jablonowski, Nicolai David

    2014-05-01

    The global demand for energy security and the mitigation of climate change are the main drivers pushing energy-plant production in Germany. However, the cultivation of these plants can cause land use conflicts since agricultural soil is mostly used for plant production. A sustainable alternative to the conventional cultivation of food-based energy-crops is the cultivation of special adopted energy-plants on marginal lands. To further increase the sustainability of energy-plant cultivation systems the dependency on synthetic fertilizers needs to be reduced via closed nutrient loops. In the presented study the energy-plant Sida hermaphrodita (Malvaceae) will be used to evaluate the potential to grow this high potential energy-crop on a marginal sandy soil in combination with fertilization via digestate from biogas production. With this dose-response experiment we will further identify an optimum dose, which will be compared to equivalent doses of NPK-fertilizer. Further, lethal doses and deficiency doses will be observed. Two weeks old Sida seedlings were transplanted to 1L pots and fertilized with six doses of digestate (equivalent to a field application of 5, 10, 20, 40, 80, 160t/ha) and three equivalent doses of NPK-fertilizer. Control plants were left untreated. Sida plants will grow for 45 days under greenhouse conditions. We hypothesize that the nutrient status of the marginal soil can be increased and maintained by defined digestate applications, compared to control plants suffering of nutrient deficiency due to the low nutrient status in the marginal substrate. The dose of 40t/ha is expected to give a maximum biomass yield without causing toxicity symptoms. Results shall be used as basis for further experiments on the field scale in a field trial that was set up to investigate sustainable production systems for energy crop production under marginal soil conditions.

  7. An outgoing energy flux boundary condition for finite difference ICRP antenna models

    International Nuclear Information System (INIS)

    Batchelor, D.B.; Carter, M.D.

    1992-11-01

    For antennas at the ion cyclotron range of frequencies (ICRF) modeling in vacuum can now be carried out to a high level of detail such that shaping of the current straps, isolating septa, and discrete Faraday shield structures can be included. An efficient approach would be to solve for the fields in the vacuum region near the antenna in three dimensions by finite methods and to match this solution at the plasma-vacuum interface to a solution obtained in the plasma region in one dimension by Fourier methods. This approach has been difficult to carry out because boundary conditions must be imposed at the edge of the finite difference grid on a point-by-point basis, whereas the condition for outgoing energy flux into the plasma is known only in terms of the Fourier transform of the plasma fields. A technique is presented by which a boundary condition can be imposed on the computational grid of a three-dimensional finite difference, or finite element, code by constraining the discrete Fourier transform of the fields at the boundary points to satisfy an outgoing energy flux condition appropriate for the plasma. The boundary condition at a specific grid point appears as a coupling to other grid points on the boundary, with weighting determined by a kemel calctdated from the plasma surface impedance matrix for the various plasma Fourier modes. This boundary condition has been implemented in a finite difference solution of a simple problem in two dimensions, which can also be solved directly by Fourier transformation. Results are presented, and it is shown that the proposed boundary condition does enforce outgoing energy flux and yields the same solution as is obtained by Fourier methods

  8. Vacuum energy and Casimir force in the presence of a dimensional parameter in the boundary condition

    International Nuclear Information System (INIS)

    Lebedev, S.L.

    2001-01-01

    The Hamiltonian for a scalar field that satisfies the boundary condition -∂ n φ=(1/δ)φ must include a surface potential energy. The corresponding term in the Casimir energy E-tilde C proves to be a leading one when the dimension of the region is l ∼ δ. The energy E-tilde C does not involve arbitrariness associated with regularization and is an unambiguously determined function of the field mass m, the size l, and the penetration depth δ. The inclusion of the surface term is of importance for ensuring that the derivative -∂ E-tilde C /∂l is equal to the ll component of the vacuum energy-momentum tensor. The Casimir energy E-tilde C is related to its volume component E C by a Legendre transformation where the quantity conjugate to 1/δ is the product of the vacuum surface energy and δ. If δ is negative and if h-bar/mc> vertical bar δ vertical bar, there exists a critical value l=l c (δ) above which (l>l c ) the vacuum is unstable; if a self-interaction of the form φ 4 is taken into account, this will lead to a phase transition accompanied by the formation of a condensate of the field φ. If δ=+0 or ∞ and if the dimensionalities are even, it is possible to construct a vacuum energy-momentum tensor (not only energy) that is finite over the entire space. Specially chosen counterterms leave unchanged the analytic dependence of the vacuum energy on the dimensionality of space and the character of the coordinate dependence of the energy density for x>h-bar/mc

  9. Energy production from grassland - Assessing the sustainability of different process chains under German conditions

    International Nuclear Information System (INIS)

    Roesch, Christine; Skarka, J.; Raab, K.; Stelzer, V.

    2009-01-01

    In many regions of Europe, grassland shapes the landscape and fulfils important functions in protecting nature, soil, and water. However, the traditional uses of grassland for forage production are vanishing with progress in breeding and structural adaptations in agriculture. On the other hand, the demand for biomass energy is rising due to political sustainability goals and financial measures to support renewable energy. Against this background, the Institute for Technology Assessment and Systems Analysis investigated the applicability, economic efficiency, and sustainability of different techniques for energy production from grassland as well as from grassland converted into maize fields or short-rotation poplars under German conditions. The results show that despite relatively high energy prices and the financial support for bioenergy, the effects of energy production from grassland on employment in agriculture and farmers' income are modest. What is beneficial are savings in non-renewable energy, reductions in greenhouse gas emissions, and local provision of energy carriers. If grassland biomass (grass silage or hay) is used for energy purposes, this brings the further advantages of preserving biodiversity and the cultural landscape and protecting of soil and groundwater. Negative impacts on sustainable development result from an increase in emissions, which leads to acidification, eutrophication, and risks to human health. The overall evaluation indicates that short-rotation poplars are comparatively advantageous from the economic and ecological point of view. Therefore, a development plan for grassland is required to identify areas where grassland could be used as an energy resource or where it would be favourable to install energy plantations with fast-growing perennial plants

  10. Building occupancy diversity and HVAC (heating, ventilation, and air conditioning) system energy efficiency

    International Nuclear Information System (INIS)

    Yang, Zheng; Ghahramani, Ali; Becerik-Gerber, Burcin

    2016-01-01

    Approximately forty percent of total building energy consumption is attributed to HVAC (heating, ventilation, and air conditioning) systems that aim to maintain healthy and comfortable indoor environments. An HVAC system is a network with several subsystems, and there exist heat transfer and balance among the zones of a building, as well as heat gains and losses through a building's envelope. Diverse occupancy (diversity in terms of when and how occupants occupy a building) in spaces could result in increase of loads that are not actual demands for an HVAC system, leading into inefficiencies. This paper introduces a framework to quantitatively evaluate the energy implications of occupancy diversity at the building level, where building information modeling is integrated to provide building geometries, HVAC system layouts, and spatial information as inputs for computing potential energy implications if occupancy diversity were to be eliminated. An agglomerate hierarchical clustering-based iterative evaluation algorithm is designed for iteratively eliminating occupancy diversity. Whole building energy simulations for a real-world building, as well as virtual reference buildings demonstrate that the proposed framework could effectively quantify the HVAC system energy efficiency affected by occupancy diversity and the framework is generalizable to different building geometries, layouts, and occupancy diversities. - Highlights: • Analyze relationships between occupancy diversity and HVAC energy efficiency. • Integrate BIM for quantifying energy implications of occupancy diversity. • Demonstrate the effectiveness and generalizability of iterative evaluation algorithm. • Improve agglomerative hierarchical clustering process using heap data structure.

  11. Instantaneous x-ray radiation energy from laser produced polystyrene plasmas for shock ignition conditions

    International Nuclear Information System (INIS)

    Shang, Wanli; Wei, Huiyue; Li, Zhichao; Yi, Rongqing; Zhu, Tuo; Song, Tianmin; Huang, Chengwu; Yang, Jiamin

    2013-01-01

    Laser target energy coupling mechanism is crucial in the shock ignition (SI) scheme, and x-ray radiation energy is a non-negligible portion of the laser produced plasma energy. To evaluate the x-ray radiation energy amount at conditions relevant to SI scheme, instantaneous x-ray radiation energy is investigated experimentally with continuum phase plates smoothed lasers irradiating layer polystyrene targets. Comparative laser pulses without and with shock spike are employed. With the measured x-ray angular distribution, full space x-ray radiation energy and conversion efficiency are observed. Instantaneous scaling law of x-ray conversion efficiency is obtained as a function of laser intensity and time. It should be pointed out that the scaling law is available for any laser pulse shape and intensity, with which irradiates polystyrene planar target with intensity from 2 × 10 14 to 1.8 × 10 15 W/cm 2 . Numerical analysis of the laser energy transformation is performed, and the simulation results agree with the experimental data

  12. Experimental determination of the energy efficiency of an air-cooled chiller under part load conditions

    International Nuclear Information System (INIS)

    Yu, F.W.; Chan, K.T.

    2005-01-01

    In cities located in a subtropical climate, air-cooled chillers are commonly used to provide cooling to the indoor environment. This accounts for the increasing electricity demand of buildings over the decades. This paper investigates how the condensing temperature serves to accurately determine the energy efficiency, or coefficient of performance (COP), of air-cooled chillers under part load conditions. An experiment on an air-cooled reciprocating chiller showed that for any given operating condition, the COP of the chiller varies, depending on how the condensing temperature is controlled. A sensitivity analysis is implemented to investigate to what extent COP is responding to changes in operating variables and confirms that the condensing temperature is an adequate variable to gauge COP under various operating conditions. The specifications of the upper limit for the condensing temperature in order to improve the energy efficiency of air-cooled chillers are discussed. The results of this work will give designers and researchers a good idea about how to model chiller energy performance curves in the thermal and energy computation exercises

  13. Construction of the Nuclear Effective Interaction from Energy Eigenstates and Boundary Conditions

    Science.gov (United States)

    McElvain, Kenneth; Haxton, Wick

    2017-01-01

    The original Harmonic Oscillator Based Effective Theory (HOBET) work by Haxton and Luu reduced H = T +VNN , with VNN a realistic potential, to Heff in a small basis defined by projection operator P while correctly including all scattering by H through an excluded space Q. Scattering by T is analytically included to all orders, leaving the ET expansion focused on the short range VNN. Results do not depend on the size P as the effect of scattering through Q is fully included, also distinguishing HOBET from other methods. In this talk we abandon VNN and determine the LECs of the ET expansion from energy levels and boundary conditions. In the infinite volume continuum case every energy is an eigenvalue of H with an associated scattering state. In the LQCD context boundary conditions are periodic. In either case the ET LECs can be determined from energy, boundary condition pairs. We show that the Cartesian HO ET LECs can be expressed in terms of the spherical ones, giving a spherical, infinite volume ET, bypassing the use of Luscher's method. The approach cleanly isolates operator mixing induced by the finite box, sequestering effects that vanish in the continuum limit in a Green's function constrained to match the boundary conditions. Supported by the DOE under contracts DE-SC00046548 and DE-AC02-98CH10886.

  14. From point-wise stress data to a continuous description of the 3D crustal in situ stress state

    Science.gov (United States)

    Heidbach, O.; Ziegler, M.; Reiter, K.; Hergert, T.

    2017-12-01

    The in situ stress is a key parameter for the safe and sustainable management of geo-reservoirs or storage of waste and energy in deep geological repositories. It is also an essential initial condition for thermo-hydro-mechanical (THM) models that investigate man-made induced processes e.g. seismicity due to fluid injection/extraction, reservoir depletion or storage of heat producing high-level radioactive waste. Without a reasonable assumption on the initial stress condition it is not possible to assess if a man-made process is pushing the system into a critical state or not. However, modelling the initial 3D stress state on reservoir scale is challenging since data are hardly available before drilling in the area of interest. This is in particular the case for the stress magnitude data which are a prerequisite for a reliable model calibration. Here, we present a multi-stage 3D geomechani­cal-numerical model approach to estimate for a reservoir-scale volume the 3D in situ stress state. First, we set up a large-scale model which is calibrated by stress data and use the modelled stress field subsequently to calibrate a small-scale model located within the large-scale model. The local model contains a significantly higher resolution representation of the subsurface geometry around boreholes of a projected geothermal power plant. This approach incorporates two models and is an alternative to the required trade-off between resolution, computational cost and calibration data which is inevitable for a single model; an extension to a three-stage approach would be straight forward. We exemplify the two-stage approach for the area around Munich in the German Molasse Basin. The results of the reservoir-scale model are presented in terms of values for slip tendency as a measure for the criticality of fault reactivation. The model results show that variations due to uncertainties in the input data are mainly introduced by the uncertain material properties and missing

  15. Photodouble ionization differential cross sections for D2 with various electron energy sharing conditions

    International Nuclear Information System (INIS)

    Seccombe, D.P.; Collins, S.A.; Reddish, T.J.; Selles, P.; Malegat, L.; Huetz, A.; Kazansky, A.K.

    2002-01-01

    The mutual angular distributions of the two ejected electrons following direct photodouble ionization have been measured for D 2 at an excess energy (E) of 25 eV using linearly polarized light. These (γ, 2e) 'triple' differential cross sections (TDCSs) were obtained for asymmetric electron energy conditions with energy sharing ratios (R=E 2 /E 1 ) of R=24, 11.5, 4 and 2.57. In all cases the 'reference' electron (energy = E 1 ) was oriented along the direction of the electric field vector (ε) and detected in coincidence with a second electron (energy = E 2 ) coplanar with ε and the photon beam direction (kγ). For comparison, helium TDCSs were obtained for the same E and R values under nearly identical spectrometer conditions. These show very good agreement with the results of hyperspherical-R-matrix with semi-classical outgoing waves calculations, thus providing even more confidence in the D 2 TDCSs where there is as yet no accurate ab initio theory. The similarities and differences between the experimental results associated with the two targets are qualitatively discussed in terms of Feagin's model (Feagin J M 1998 J. Phys. B: At. Mol. Opt. Phys. 31 L729). (author)

  16. System monitoring feedback in cinemas and harvesting energy of the air conditioning condenser

    Science.gov (United States)

    Pop, P. P.; Pop-Vadean, A.; Barz, C.; Latinovic, T.; Chiver, O.

    2017-05-01

    Our article monitors the degree of emotional involvement of the audience in the action film in theaters by measuring the concentration of CO2. The software performs data processing obtained dispersion sensors and displays data during the film. The software will also trigger the start of the air conditioning condenser where we can get harvesting energy by installing a piezoelectric device. Useful energy can be recovered from various waste produced in cinema. The time lag between actions and changes in environmental systems determines that decisions made now will affect subsequent generations and the future of our environment.

  17. A support of the renewable source energy utilization and conditions for the biogass station investment

    Directory of Open Access Journals (Sweden)

    Roland Weiss

    2009-03-01

    Full Text Available This paper describes possibilities of the renewable energy source projects funding and arises an importance of the analysis whichshould be the first step before investing in the generation of energy from renewable sources.The issue of investing in biogas plants is related to particular conditions of the investor. The extent of the investment is never clearand always depends on the company equipment. Therefore, the quality evaluation of the project in the preparatory phase can protectthe investor against a direct damage and disappointment.

  18. Air-conditioning in the 21st century: impact on human productivity and energy consumption

    DEFF Research Database (Denmark)

    Fanger, Povl Ole

    2000-01-01

    Although air-conditioning has played a positive role for economic development in warm climates, its image is globally mixed. Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from Sick Building Syndrome (SBS) symptoms...... environment on human productivity, health and comfort. The principles of excellence can be provided with moderate energy consumption. But the success of excellent indoor environments will increase the demand for improvement globally and the required energy supply will provide a challenge for the world...

  19. Energy metabolism in human melanoma cells under hypoxic and acidic conditions in vitro.

    Science.gov (United States)

    Skøyum, R; Eide, K; Berg, K; Rofstad, E K

    1997-01-01

    The response to treatment and the malignant progression of tumours are influenced by the ability of the tumour cells to withstand severe energy deprivation during prolonged exposure to hypoxia at normal or low extracellular pH (pHe). The objective of the present work was to demonstrate intertumour heterogeneity under conditions of microenvironment-induced energy deprivation and to investigate whether the heterogeneity can be attributed to differences in the capacity of the tumour cells to generate energy in an oxygen-deficient microenvironment. Cultures of four human melanoma cell lines (BEX-c, COX-c, SAX-c, WIX-c) were exposed to hypoxia in vitro at pHe 7.4, 7.0 or 6.6 for times up to 31 h by using the steel-chamber method. High-performance liquid chromatography was used to assess adenylate energy charge as a function of exposure time. Cellular rates of glucose uptake and lactate release were determined by using standard enzymatic test kits. The adenylate energy charge decreased with time under hypoxia in all cell lines. The decrease was most pronounced shortly after the treatment had been initiated and then tapered off. BEX-c and SAX-c showed a significantly higher adenylate energy charge under hypoxic conditions than did COX-c and WIX-c whether the pHe was 7.4, 7.0 or 6.6, showing that tumours can differ in the ability to avoid energy deprivation during microenvironmental stress. There was no correlation between the adenylate energy charge and the rates of glucose uptake and lactate release. Intertumour heterogeneity in the ability to withstand energy deprivation in an oxygen-deficient microenvironment cannot therefore be attributed mainly to differences in the capacity of the tumour cells to generate energy by anaerobic metabolism. The data presented here suggest that the heterogeneity is rather caused by differences in the capacity of the tumour cells to reduce the rate of energy consumption when exposed to hypoxia.

  20. Microclimate design methods for energy-saving houses on various site conditions in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Kyeong

    2008-07-09

    A small area can have several different microclimates depending on how much sunlight, shade or wind are exposed on the area. Microclimate can be influenced by inclined terrain, surfaces, and 3-dimensionally geometry such as combinations of architectural elements and annex buildings. This study investigates microclimate modification for energy-saving using design elements of Korean traditional and passive house. Microclimate analysis method in this study enables to predict temporal and spatial variances in the building geometry. A combination of passive solar heating, cold wind blocking, indoor air circulation, natural ventilation cooling and shading etc, seasonally help to form a comfort condition with less energy consumption. The passive heating and cooling controls with microclimate modification are efficient to accomplish the energy efficiency in the building. This work includes the microclimate modifications of the high-performance designs, microclimate energy-saving methods, Passive House design methods, and common physical bases in energy simulation methods. For hot and humid summer in Korea, ventilation is beneficial for convective or evaporative cooling. The air flow through a building geometry is generated by differences in air temperature and pressure. The layout of surrounding buildings acts as barriers and diverts the flow into narrower. The resulted patterns of airflow are affected more by building geometry and orientation than by air speed. A novel simulation method combining multi-zone and CFD energy simulations is used to analyze energy-saving aspects in passive and microclimate design elements. EnergyPlus is a multi-zone energy simulation tool that uses a parameterization to simplify the energy-saving problem for each zone. However, the model is not appropriate to handle variations in the building geometry since it estimates only the average value for each volume. On the contrary, CFD method with subdivided grid units is more suitable to estimate

  1. EFFECT OF MECHANICAL CONDITIONING ON THIN-LAYER DRYING OF ENERGY SORGHUM (Sorghum bicolor (L.) Moench)

    Energy Technology Data Exchange (ETDEWEB)

    Ian J. Bonner; Kevin L. Kenney

    2012-10-01

    Cellulosic energy varieties of Sorghum bicolor (L.) Moench show promise as a bioenergy feedstock, however, high moisture content at the time of harvest results in unacceptable levels of degradation when stored in aerobic conditions. To safely store sorghum biomass for extended periods in baled format, the material must be dried to inhibit microbial growth. One possible solution is allowing the material to dry under natural in-field conditions. This study examines the differences in thin-layer drying rates of intact and conditioned sorghum under laboratory-controlled temperatures and relative humidity levels (20 degrees C and 30 degrees C from 40% to 85% relative humidity), and models experimental data using the Page’s Modified equation. The results demonstrate that conditioning drastically accelerates drying times. Relative humidity had a large impact on the time required to reach a safe storage moisture content for intact material (approximately 200 hours at 30 degrees C and 40% relative humidity and 400 hours at 30 degrees C and 70% relative humidity), but little to no impact on the thin-layer drying times of conditioned material (approximately 50 hours for all humidity levels < 70% at 30 degrees C). The drying equation parameters were influenced by temperature, relative humidity, initial moisture content, and material damage, allowing drying curves to be empirically predicted. The results of this study provide valuable information applicable to the agricultural community and to future research on drying simulation and management of energy sorghum.

  2. Rate-Independent Processes with Linear Growth Energies and Time-Dependent Boundary Conditions

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Zimmer, J.

    2012-01-01

    Roč. 5, č. 3 (2012), s. 591-604 ISSN 1937-1632 R&D Projects: GA AV ČR IAA100750802 Grant - others:GA ČR(CZ) GAP201/10/0357 Institutional research plan: CEZ:AV0Z10750506 Keywords : concentrations * oscillations * time - dependent boundary conditions * rate-independent evolution Subject RIV: BA - General Mathematics http://library.utia.cas.cz/separaty/2011/MTR/kruzik-rate-independent processes with linear growth energies and time - dependent boundary conditions.pdf

  3. A digital computer simulation and study of a direct-energy-transfer power-conditioning system

    Science.gov (United States)

    Burns, W. W., III; Owen, H. A., Jr.; Wilson, T. G.; Rodriguez, G. E.; Paulkovich, J.

    1975-01-01

    An investigation of the behavior of the power-conditioning system as a whole is a necessity to ensure the integrity of the aggregate system in the case of space applications. An approach for conducting such an investigation is considered. A description is given of the application of a general digital analog simulator program to the study of an aggregate power-conditioning system which is being developed for use on the International Ultraviolet Explorer spacecraft. The function of the direct energy transfer system studied involves a coupling of a solar array through a main distribution bus to the spacecraft electrical loads.

  4. Towards energy efficient operation of Heating, Ventilation and Air Conditioning systems via advanced supervisory control design

    Science.gov (United States)

    Oswiecinska, A.; Hibbs, J.; Zajic, I.; Burnham, K. J.

    2015-11-01

    This paper presents conceptual control solution for reliable and energy efficient operation of heating, ventilation and air conditioning (HVAC) systems used in large volume building applications, e.g. warehouse facilities or exhibition centres. Advanced two-level scalable control solution, designed to extend capabilities of the existing low-level control strategies via remote internet connection, is presented. The high-level, supervisory controller is based on Model Predictive Control (MPC) architecture, which is the state-of-the-art for indoor climate control systems. The innovative approach benefits from using passive heating and cooling control strategies for reducing the HVAC system operational costs, while ensuring that required environmental conditions are met.

  5. Long-term biomass resources for energy aim - quantities, costs and conditions of the market

    International Nuclear Information System (INIS)

    Gylling, M.; Abildtrup, J.; Vodder Nielsen, K.; Petersen, S.M.; Varming, S.

    2001-01-01

    This project assesses the agricultural, technical and economic possibilities for producing the planned quantity of energy crops in year 2015. The assessments in this project are based on two essential assumptions: 1) The total demand for straw and energy crops to meet the energy plans is added up, and the available amount of straw is used first and energy crops will be used for the remaining amount. 2) As long as the present economic conditions for set-aside prevails, it will only be the set-aside areas that will be available for energy crop production. Energy crops are not seen as economic competitive with other cash-crops on the reform areas.Three different scenarios for the agricultural crop production up to year 2015 are outlined; a reference scenario where the current development is extrapolated; an environment scenario in which a higher degree of environmental awareness is taken into account and a market scenario in which the economic competitiveness of agricultural production gains more focus. (au)

  6. Pressure retarded osmosis for energy production: membrane materials and operating conditions.

    Science.gov (United States)

    Kim, H; Choi, J-S; Lee, S

    2012-01-01

    Pressure retarded osmosis (PRO) is a novel membrane process to produce energy. PRO has the potential to convert the osmotic pressure difference between fresh water (i.e. river water) and seawater to electricity. Moreover, it can recover energy from highly concentrated brine in seawater desalination. Nevertheless, relatively little research has been undertaken for fundamental understanding of the PRO process. In this study, the characteristics of the PRO process were examined using a proof-of-concept device. Forward osmosis (FO), reverse osmosis (RO), and nanofiltration (NF) membranes were compared in terms of flux rate and concentration polarization ratio. The results indicated that the theoretical energy production by PRO depends on the membrane type as well as operating conditions (i.e. back pressure). The FO membrane had the highest energy efficiency while the NF membrane had the lowest efficiency. However, the energy production rate was low due to high internal concentration polarization (ICP) in the PRO membrane. This finding suggests that the control of the ICP is essential for practical application of PRO for energy production.

  7. Energy conditions of non-singular black hole spacetimes in conformal gravity

    Energy Technology Data Exchange (ETDEWEB)

    Toshmatov, Bobir [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics, Opava (Czech Republic); Ulugh Beg Astronomical Institute, Tashkent (Uzbekistan); Bambi, Cosimo [Fudan University, Department of Physics, Center for Field Theory and Particle Physics, Shanghai (China); Eberhard-Karls Universitaet Tuebingen, Theoretical Astrophysics, Tuebingen (Germany); Ahmedov, Bobomurat [Ulugh Beg Astronomical Institute, Tashkent (Uzbekistan); National University of Uzbekistan, Tashkent (Uzbekistan); Abdujabbarov, Ahmadjon [Ulugh Beg Astronomical Institute, Tashkent (Uzbekistan); National University of Uzbekistan, Tashkent (Uzbekistan); Tashkent University of Information Technologies, Tashkent (Uzbekistan); Stuchlik, Zdenek [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics, Opava (Czech Republic)

    2017-08-15

    Conformal gravity can elegantly solve the problem of spacetime singularities present in Einstein's gravity. For every physical spacetime, there is an infinite family of conformally equivalent singularity-free metrics. In the unbroken phase, every non-singular metric is equivalent and can be used to infer the physical properties of the spacetime. In the broken phase, a Higgs-like mechanism should select a certain vacuum, which thus becomes the physical one. However, in the absence of the complete theoretical framework we do not know how to select the right vacuum. In this paper, we study the energy conditions of non-singular black hole spacetimes obtained in conformal gravity assuming they are solutions of Einstein's gravity with an effective energy-momentum tensor. We check whether such conditions can be helpful to select the vacuum of the broken phase. (orig.)

  8. Energy conditions of non-singular black hole spacetimes in conformal gravity

    International Nuclear Information System (INIS)

    Toshmatov, Bobir; Bambi, Cosimo; Ahmedov, Bobomurat; Abdujabbarov, Ahmadjon; Stuchlik, Zdenek

    2017-01-01

    Conformal gravity can elegantly solve the problem of spacetime singularities present in Einstein's gravity. For every physical spacetime, there is an infinite family of conformally equivalent singularity-free metrics. In the unbroken phase, every non-singular metric is equivalent and can be used to infer the physical properties of the spacetime. In the broken phase, a Higgs-like mechanism should select a certain vacuum, which thus becomes the physical one. However, in the absence of the complete theoretical framework we do not know how to select the right vacuum. In this paper, we study the energy conditions of non-singular black hole spacetimes obtained in conformal gravity assuming they are solutions of Einstein's gravity with an effective energy-momentum tensor. We check whether such conditions can be helpful to select the vacuum of the broken phase. (orig.)

  9. Communication: modeling charge-sign asymmetric solvation free energies with nonlinear boundary conditions.

    Science.gov (United States)

    Bardhan, Jaydeep P; Knepley, Matthew G

    2014-10-07

    We show that charge-sign-dependent asymmetric hydration can be modeled accurately using linear Poisson theory after replacing the standard electric-displacement boundary condition with a simple nonlinear boundary condition. Using a single multiplicative scaling factor to determine atomic radii from molecular dynamics Lennard-Jones parameters, the new model accurately reproduces MD free-energy calculations of hydration asymmetries for: (i) monatomic ions, (ii) titratable amino acids in both their protonated and unprotonated states, and (iii) the Mobley "bracelet" and "rod" test problems [D. L. Mobley, A. E. Barber II, C. J. Fennell, and K. A. Dill, "Charge asymmetries in hydration of polar solutes," J. Phys. Chem. B 112, 2405-2414 (2008)]. Remarkably, the model also justifies the use of linear response expressions for charging free energies. Our boundary-element method implementation demonstrates the ease with which other continuum-electrostatic solvers can be extended to include asymmetry.

  10. Communication: Modeling charge-sign asymmetric solvation free energies with nonlinear boundary conditions

    International Nuclear Information System (INIS)

    Bardhan, Jaydeep P.; Knepley, Matthew G.

    2014-01-01

    We show that charge-sign-dependent asymmetric hydration can be modeled accurately using linear Poisson theory after replacing the standard electric-displacement boundary condition with a simple nonlinear boundary condition. Using a single multiplicative scaling factor to determine atomic radii from molecular dynamics Lennard-Jones parameters, the new model accurately reproduces MD free-energy calculations of hydration asymmetries for: (i) monatomic ions, (ii) titratable amino acids in both their protonated and unprotonated states, and (iii) the Mobley “bracelet” and “rod” test problems [D. L. Mobley, A. E. Barber II, C. J. Fennell, and K. A. Dill, “Charge asymmetries in hydration of polar solutes,” J. Phys. Chem. B 112, 2405–2414 (2008)]. Remarkably, the model also justifies the use of linear response expressions for charging free energies. Our boundary-element method implementation demonstrates the ease with which other continuum-electrostatic solvers can be extended to include asymmetry

  11. Communication: Modeling charge-sign asymmetric solvation free energies with nonlinear boundary conditions

    Science.gov (United States)

    Bardhan, Jaydeep P.; Knepley, Matthew G.

    2014-01-01

    We show that charge-sign-dependent asymmetric hydration can be modeled accurately using linear Poisson theory after replacing the standard electric-displacement boundary condition with a simple nonlinear boundary condition. Using a single multiplicative scaling factor to determine atomic radii from molecular dynamics Lennard-Jones parameters, the new model accurately reproduces MD free-energy calculations of hydration asymmetries for: (i) monatomic ions, (ii) titratable amino acids in both their protonated and unprotonated states, and (iii) the Mobley “bracelet” and “rod” test problems [D. L. Mobley, A. E. Barber II, C. J. Fennell, and K. A. Dill, “Charge asymmetries in hydration of polar solutes,” J. Phys. Chem. B 112, 2405–2414 (2008)]. Remarkably, the model also justifies the use of linear response expressions for charging free energies. Our boundary-element method implementation demonstrates the ease with which other continuum-electrostatic solvers can be extended to include asymmetry. PMID:25296776

  12. Communication: Modeling charge-sign asymmetric solvation free energies with nonlinear boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bardhan, Jaydeep P. [Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115 (United States); Knepley, Matthew G. [Computation Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

    2014-10-07

    We show that charge-sign-dependent asymmetric hydration can be modeled accurately using linear Poisson theory after replacing the standard electric-displacement boundary condition with a simple nonlinear boundary condition. Using a single multiplicative scaling factor to determine atomic radii from molecular dynamics Lennard-Jones parameters, the new model accurately reproduces MD free-energy calculations of hydration asymmetries for: (i) monatomic ions, (ii) titratable amino acids in both their protonated and unprotonated states, and (iii) the Mobley “bracelet” and “rod” test problems [D. L. Mobley, A. E. Barber II, C. J. Fennell, and K. A. Dill, “Charge asymmetries in hydration of polar solutes,” J. Phys. Chem. B 112, 2405–2414 (2008)]. Remarkably, the model also justifies the use of linear response expressions for charging free energies. Our boundary-element method implementation demonstrates the ease with which other continuum-electrostatic solvers can be extended to include asymmetry.

  13. Influence of experimental conditions on atom column visibility in energy dispersive X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dycus, J.H.; Xu, W.; Sang, X. [Department of Materials Science and Engineering, North Carolina State University, 911 Partners Way Engineering Building 1, Raleigh, NC 27606 (United States); D' Alfonso, A.J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Chen, Z. [School of Physics and Astronomy, Monash University, Clayton, Victoria 3800 (Australia); Weyland, M. [Monash Centre for Electron Microscopy, Monash University, Clayton, Victoria 3800 (Australia); Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800 (Australia); Allen, L.J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Findlay, S.D. [School of Physics and Astronomy, Monash University, Clayton, Victoria 3800 (Australia); LeBeau, J.M., E-mail: jmlebeau@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, 911 Partners Way Engineering Building 1, Raleigh, NC 27606 (United States)

    2016-12-15

    Here we report the influence of key experimental parameters on atomically resolved energy dispersive X-ray spectroscopy (EDX). In particular, we examine the role of the probe forming convergence semi-angle, sample thickness, lattice spacing, and dwell/collection time. We show that an optimum specimen-dependent probe forming convergence angle exists to maximize the signal-to-noise ratio of the atomically resolved signal in EDX mapping. Furthermore, we highlight that it can be important to select an appropriate dwell time to efficiently process the X-ray signal. These practical considerations provide insight for experimental parameters in atomic resolution energy dispersive X-ray analysis. - Highlights: • Impacts of microscope operating conditions on EDX signal and atom column contrast are demonstrated. • Influence of sample thickness and lattice spacing is shown. • Conditions for obtaining optimal signal and contrast for different sample types are discussed. • Effects of dwell time during EDX acquisition are discussed.

  14. Standardization of the energy performance of photovoltaic modules in real operating conditions

    Directory of Open Access Journals (Sweden)

    Viganó Davide

    2014-01-01

    Full Text Available The performance of a PV module at STC [1] is a useful indicator for comparing the peak performance of different module types, but on its own is not sufficient to accurately predict how much energy a module will deliver in the field when subjected to a wide range of real operating conditions [2]. An Energy Rating approach has to be preferred for that aim. It is currently under development the standard series IEC 61853 on Energy Rating, for which only part 1 [3] has been issued. It describes methods to characterize the module performance as a function of irradiance and temperature. The reproducibility of the power matrix measurements obtained by the three different methods specified in the standard, namely: under natural sunlight using a tracking system; under natural sunlight without tracker; and a large area pulsed solar simulator of Class AAA were evaluated and discussed [4,5]. The work here presented is focused on the second method listed above, which explores the real working conditions for a PV device and therefore it represents the situation where Energy Rating procedures are expected to give the largest deviations from the STC predictions. The system for continuous monitoring of module performances, already implemented at ESTI, has been recently replaced with a new system having a number of improvements described in the following. The two system results have been compared showing a discrete compatibility. The two power matrices are then merged together using a weighted average and compared to those acquired with the other two remaining “ideal” systems. An interesting tendency seems to come up from this comparison, making the power rating under real operating conditions an essential procedure for energy rating purposes.

  15. Development of energy-saving technologies providing comfortable microclimate conditions for mining

    OpenAIRE

    Б. П. Казаков; Л. Ю. Левин; А. В. Шалимов; А. В. Зайцев

    2017-01-01

    The paper contains analysis of natural and technogenic factors influencing properties of mine atmosphere, defining level of mining safety and probability of emergencies. Main trends in development of energy-saving technologies providing comfortable microclimate conditions are highlighted. A complex of methods and mathematical models has been developed to carry out aerologic and thermophysical calculations. Main ways of improvement for existing calculation methods of stationary and non-station...

  16. Energy and cusp-conditions study for the He isoelectronic sequence

    Energy Technology Data Exchange (ETDEWEB)

    Otranto, S. E-mail: sotranto@uns.edu.ar; Gasaneo, G. E-mail: ggasaneo@criba.edu.ar; Garibotti, C.R

    2004-03-01

    We present variational wave functions for He-like atoms with nuclear charge Z=1,...,10. We propose modifications of some usual simple correlated wave functions to account for the integration factor required in the evaluation of atomic ionization and excitation amplitudes with distorted wave methods. We determine the parameters of the trial functions and the resulting energies. We introduce new procedures to test the cusp conditions at the singularities of the Coulomb field.

  17. The linear attenuation coefficients as features of multiple energy CT image classification

    International Nuclear Information System (INIS)

    Homem, M.R.P.; Mascarenhas, N.D.A.; Cruvinel, P.E.

    2000-01-01

    We present in this paper an analysis of the linear attenuation coefficients as useful features of single and multiple energy CT images with the use of statistical pattern classification tools. We analyzed four CT images through two pointwise classifiers (the first classifier is based on the maximum-likelihood criterion and the second classifier is based on the k-means clustering algorithm) and one contextual Bayesian classifier (ICM algorithm - Iterated Conditional Modes) using an a priori Potts-Strauss model. A feature extraction procedure using the Jeffries-Matusita (J-M) distance and the Karhunen-Loeve transformation was also performed. Both the classification and the feature selection procedures were found to be in agreement with the predicted discrimination given by the separation of the linear attenuation coefficient curves for different materials

  18. Expression for the thermal H-mode energy confinement time under ELM-free conditions

    International Nuclear Information System (INIS)

    Ryter, F.; Gruber, O.; Kardaun, O.J.W.F.; Menzler, H.P.; Wagner, F.; Schissel, D.P.; DeBoo, J.C.; Kaye, S.M.

    1992-07-01

    The design of future tokamaks, which are supposed to reach ignition with the H-mode, requires a reliable scaling expression for the H-mode energy confinement time. In the present work, an H-mode scaling expression for the thermal plasma energy confinement time has been developed by combining data from four existing divertor tokamaks, ASDEX, DIII-D, JET and PBX-M. The plasma conditions, which were as similar as possible to ensure a coherent set of data, were ELM-free deuterium discharges heated by deuterium neutral beam injection. By combining four tokamaks, the parametric dependence of the thermal energy confinement on the main plasma parameters, including the three main geometrical variables, was determined. (orig./WL)

  19. Cool roofs and the influence on the energy consumption under Danish conditions

    DEFF Research Database (Denmark)

    Brandt, Erik; Bunch-Nielsen, Tommy; Juhl, Lasse

    Experience from countries in warm climates has shown that the color of the roofing material has a significant effect on the energy consumption of the building. Especially changing from black to white roofing material provides reduction in energy consumption. The investigated roofs have been...... with a moderate amount of thermal insulation. The Danish Roofing Advisory Board in Denmark has conducted an analysis of the effects of roofing color on buildings energy consumption under Danish conditions i.e. with a colder climate and with a larger amount of thermal insulation. An experiment was performed...... in order to study the effects of the roofing color on the temperature distribution in a roof structure. The studied roof specimens were flat roofs covered with roofing felt in different colors. Temperatures have been measured in the roofing felt as well as in the middle and the bottom of the structure...

  20. Evaluation Framework and Analyses for Thermal Energy Storage Integrated with Packaged Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kung, F.; Deru, M.; Bonnema, E.

    2013-10-01

    Few third-party guidance documents or tools are available for evaluating thermal energy storage (TES) integrated with packaged air conditioning (AC), as this type of TES is relatively new compared to TES integrated with chillers or hot water systems. To address this gap, researchers at the National Renewable Energy Laboratory conducted a project to improve the ability of potential technology adopters to evaluate TES technologies. Major project outcomes included: development of an evaluation framework to describe key metrics, methodologies, and issues to consider when assessing the performance of TES systems integrated with packaged AC; application of multiple concepts from the evaluation framework to analyze performance data from four demonstration sites; and production of a new simulation capability that enables modeling of TES integrated with packaged AC in EnergyPlus. This report includes the evaluation framework and analysis results from the project.

  1. Residential solar air conditioning: Energy and exergy analyses of an ammonia–water absorption cooling system

    International Nuclear Information System (INIS)

    Aman, J.; Ting, D.S.-K.; Henshaw, P.

    2014-01-01

    Large scale heat-driven absorption cooling systems are available in the marketplace for industrial applications but the concept of a solar driven absorption chiller for air-conditioning applications is relatively new. Absorption chillers have a lower efficiency than compression refrigeration systems, when used for small scale applications and this restrains the absorption cooling system from air conditioning applications in residential buildings. The potential of a solar driven ammonia–water absorption chiller for residential air conditioning application is discussed and analyzed in this paper. A thermodynamic model has been developed based on a 10 kW air cooled ammonia–water absorption chiller driven by solar thermal energy. Both energy and exergy analyses have been conducted to evaluate the performance of this residential scale cooling system. The analyses uncovered that the absorber is where the most exergy loss occurs (63%) followed by the generator (13%) and the condenser (11%). Furthermore, the exergy loss of the condenser and absorber greatly increase with temperature, the generator less so, and the exergy loss in the evaporator is the least sensitive to increasing temperature. -- Highlights: • 10 kW solar thermal driven ammonia–water air cooled absorption chiller is investigated. • Energy and exergy analyses have been done to enhance the thermal performance. • Low driving temperature heat sources have been optimized. • The efficiencies of the major components have been evaluated

  2. Proposal for energy saving in air conditioning equipment; Propuesta para ahorro energetico en acondicionadores de aire

    Energy Technology Data Exchange (ETDEWEB)

    Solis Recendez, Daniel H [Division de Ingenieria Electrica, Universidad Nacional Autonoma de Mexico (Mexico)

    2008-10-15

    In the last decades, the air conditioning systems have become a crucial part in the search from comfort in extreme climates. Nevertheless, they have also become one of the greatest energy consumers. In this article it is proposed that the final conditions that the air conditioning equipment looks for not to be fixed, but variable in respect to a certain comfort zone. This zone is a variation of the used one in the bio-climatic chart of Olgyay that considers the rapidity whereupon the reached conditions tend to leave the comfort zone. It is analyzed how to choose the point on the zone that costs less energy in arriving to it. [Spanish] En las ultimas decadas, los sistemas de aire acondicionado se han vuelto una parte crucial en la busqueda de confort en climas extremosos. Sin embargo, tambien se han vuelto de los mayores consumidores de energia. En este articulo se propone que las condiciones finales que busquen lograr los acondicionadores no sean fijas, si no variables respecto a una determinada zona de confort. Dicha zona es una variacion de la utilizada en la carta bioclimatica de Olgyay, que considera la rapidez con que las condiciones alcanzadas tienden a abandonar la zona de confort. Se discute como elegir el punto sobre la zona que cueste menos energia en llegara el.

  3. Comparative economic assessment of the energy performance of air-conditioning within the Mexican residential sector

    Directory of Open Access Journals (Sweden)

    Ivan Oropeza-Perez

    2016-11-01

    Full Text Available This work shows a sensitivity analysis of the economic impact of different energy performances of air-conditioning within the Mexican housing sector. For this purpose, a cooling-load calculator program in function of the indoor temperature is developed. The program also calculates the electricity consumption along with the expenditure with the different residential rates of the Mexican Federal Commission of Electricity (CFE, initials in Spanish set according to the season of the year and zone of the country. After the results onto the national-scale scenario are validated with the literature, a sensitivity analysis is carried out by changing three parameters that are considered as influential on the consumption and which can be considered as energy saving strategies. With these strategies, it is found that the indoor temperature decrease due to the use of a passive cooling system is the most important characteristic to take into account followed by the coefficient of performance (COP of the air-conditioning and the increase of the comfort temperature set-point, respectively. Thereby, an economic analysis is carried out, finding an annual saving up to 770 USD within a single air-conditioned dwelling having a payback period of 3 years for using a combination of passive cooling techniques and increasing the comfort temperature set-point; or a 2 years payback period if the air-conditioning is changed by a high-efficient equipment.

  4. The improving of the heat networks operating process under the conditions of the energy efficiency providing

    Directory of Open Access Journals (Sweden)

    Blinova Tatiana

    2016-01-01

    Full Text Available Among the priorities it is important to highlight the modernization and improvement of energy efficiency of housing and communal services, as well as the transition to the principle of using the most efficient technologies used in reproduction (construction, creation of objects of municipal infrastructure and housing modernization. The main hypothesis of this study lies in the fact that in modern conditions the realization of the most important priorities of the state policy in the sphere of housing and communal services, is possible in the conditions of use of the most effective control technologies for the reproduction of thermal networks. It is possible to raise the level of information security Heat Distribution Company, and other market participants by improving business processes through the development of organizational and economic mechanism in the conditions of complex monitoring of heat network operation processes

  5. Level of energy restriction alters body condition score and morphometric profile in obese Shetland ponies.

    Science.gov (United States)

    Bruynsteen, L; Moons, C P H; Janssens, G P J; Harris, P A; Vandevelde, K; Lefère, L; Duchateau, L; Hesta, M

    2015-10-01

    Due to the high prevalence of obesity in some horses and ponies (especially in the leisure horse sector), effective and safe weight loss strategies are required. The present study evaluated the effect of two different energy restriction rates on physical, morphometric and welfare parameters in 18 obese (body condition score [BCS] 7-9/9) Shetland geldings. The trial was divided into three periods: (1) a 4 week adaptation period, during which the maintenance energy intakes to maintain a stable obese bodyweight were determined (100% MERob); (2) a 16.5-week weight loss period during which the ponies were randomly divided into three groups (n = 6/group) comprising a control group (CONTROL), moderate energy restricted (MOD), and severe energy restricted (SEV) groups that were respectively fed at 100%, 80% and 60% of their individual MERob; and (3) a 3 week follow up period in which the ponies were again fed at their outset individual 100% MERob. Between the start and end of the weight loss period, significant pairwise differences between the three treatment groups were seen for bodyweight, BCS, heart girth, belly girth, and relative ultrasound fat depth at the level of loin and ribs at several time points (P < 0.05). The higher energy restriction was associated with a faster decrease in BCS, tail head, and heart plus belly girth, but no gastric ulcers or stereotypic behaviours were seen. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Optimization of operating conditions of distillation columns: an energy saving option in refinery industry

    Directory of Open Access Journals (Sweden)

    Alireza Fazlali

    2010-01-01

    Full Text Available While energy prices continue to climb, it conservation remains the prime concern for process industries. The daily growth of energy consumption throughout the world and the real necessity of providing it, shows that optimization of energy generation and consumption units is an economical and sometimes vital case. Hence, the optimization of a petroleum refinery is aimed towards great production and an increase in quality. In this research, the atmospheric distillation unit of the Iran-Arak-Shazand petroleum refinery was subject to optimization efforts. It was performed by the means of using a simulator with the aim to earn more overhead products. In the next step the optimization results from the simulators were carried out in the real world, at the above mentioned unit. Results demonstrate that the changes in the real operating conditions increase the overhead products with desirable quality. Finally, a net economical balance between the increments of the overhead products and the energy consumption shows an energy saving in this refinery.

  7. Energy-Saving Benefits of Adiabatic Humidification in the Air Conditioning Systems of Semiconductor Cleanrooms

    Directory of Open Access Journals (Sweden)

    Min-Suk Jo

    2017-11-01

    Full Text Available This paper aimed to evaluate the applicability of adiabatic humidification in the heating, ventilation, and air conditioning (HVAC systems of semiconductor cleanrooms. Accurate temperature and humidity control are essential in semiconductor cleanrooms and high energy consumption steam humidification is commonly used. Therefore, we propose an adiabatic humidification system employing a pressurized water atomizer to reduce the energy consumption. The annual energy consumption of three different HVAC systems were analyzed to evaluate the applicability of adiabatic humidification. The studied cases were as follows: (1 CASE 1: a make-up air unit (MAU with a steam humidifier, a dry cooling coil (DCC, and a fan filter unit (FFU; (2 CASE 2: a MAU with the pressurized water atomizer, a DCC, and a FFU; and (3 CASE 3: a MAU, a DCC, and a FFU, and the pressurized water atomizer installed in the return duct. The energy saving potential of adiabatic humidification over steam humidification has been proved, with savings of 8% and 23% in CASE 2 and CASE 3 compared to CASE 1, respectively. Furthermore, the pressurized water atomizer installed in the return duct exhibits greater energy saving effect than when installed in the MAU.

  8. Effect of operating conditions on energy efficiency for a small passive direct methanol fuel cell

    International Nuclear Information System (INIS)

    Chu Deryn; Jiang Rongzhong

    2006-01-01

    Energy conversion efficiency was studied in a direct methanol fuel cell (DMFC) with an air-breathing cathode using Nafion 117 as electrolyte membrane. The effect of operating conditions, such as methanol concentration, discharge voltage and temperature, on Faradic and energy conversion efficiencies was analyzed under constant voltage discharge with quantitative amount of fuel. Both of Faradic and energy conversion efficiencies decrease significantly with increasing methanol concentration and environmental temperature. The Faradic conversion efficiency can be as high as 94.8%, and the energy conversion efficiency can be as high as 23.9% if the environmental temperature is low enough (10 deg. C) under constant voltage discharge at 0.6 V with 3 M methanol for a DMFC bi-cell. Although higher temperature and higher methanol concentration can achieve higher discharge power, it will result in considerable losses of Faradic and energy conversion efficiencies for using Nafion electrolyte membrane. Development of alternative highly conductive membranes with significantly lower methanol crossover is necessary to avoid loss of Faradic conversion efficiency with temperature and with fuel concentration

  9. Analysis of energy management for heating, ventilating and air-conditioning systems

    Directory of Open Access Journals (Sweden)

    Mohamed Elhelw

    2016-06-01

    Full Text Available In the office buildings, large energy is consumed due to poor thermal performance and low efficiencies of HVAC systems. A cooling load calculation is a basis for the design of building cooling systems. The current design methods are usually based on deterministic cooling loads, which are obtained by using design parameters. However, these parameters contain uncertainties, and they will be different from that used in the design calculation when the cooling system is put in use. The actual cooling load profile will deviate from that predicted in design. A modified bin method was used in this paper to optimize the energy efficiency ratio (EER. A design optimization method is proposed by considering uncertainties related to the cooling load calculation. Impacts caused by the uncertainties of seven factors are considered, including the outdoor weather conditions and internal heat sources. The cooling load distribution is analyzed. Comparison between the modified bin method and CLTD/SCL/CLF method is also conducted. With the distributions of their energy consumption, decision makers can select the optimal configuration based on quantified confidence. According to the economic benefits and energy efficiency ratio, using modified bin method will increase the overall energy efficiency ratio by 45.57%.

  10. Biogas production from high-yielding energy crops in boreal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Seppala, M.

    2013-11-01

    In this thesis, the methane production potential of traditional and novel energy crops was evaluated in boreal conditions. The highest methane yield per hectare was achieved with maize (4 000-9 200 m{sup 3}CH{sub 4} ha{sup -1} a{sup -1}) and the second highest with brown knapweed (2 700-6 100 m{sup 3}CH{sub 4} ha{sup -1} a{sup -1}). Recently, the most feasible energy crop, grass, produced 1 200-3 600 m{sup 3}CH{sub 4} ha{sup -1} a{sup -1}. The specific methane yields of traditional and novel energy crops varied from 170-500 l kg{sup -1} volatile solid (VS). The highest specific methane yields were obtained with maize, while the novel energy crops were at a lower range. The specific methane yields decreased in the later harvest time with maize and brown knapweed, and the specific methane yield of the grasses decreased from the 1st to 2nd harvests. Maize and brown knapweed produced the highest total solid (TS) yields per hectare 13-23 tTS ha{sup -1}, which were high when compared with the TS yields of grasses (6-13 tTS ha{sup -1}). The feasibility of maize and brown knapweed in co-digestion with liquid cow manure, in continuously stirred tank reactors (CSTR), was evaluated. According to the CSTR runs, maize and brown knapweed are suitable feeds and have stable processes, producing the highest methane yields (organic loading rate 2 kgVS m{sup -3}d{sup -1}), with maize at 259 l kgVS{sup -1} and brown knapweed at 254 l kgVS{sup -1}. The energy balance (input/output) of the cultivation of the grasses, maize and brown knapweed was calculated in boreal conditions, and it was better when the digestate was used as a fertilizer (1.8-4.8 %) than using chemical fertilizers (3.7-16.2 %), whose production is the most energy demanding process in cultivation. In conclusion, the methane production of maize, grasses and novel energy crops can produce high methane yields and are suitable feeds for anaerobic digestion. The cultivation managements of maize and novel energy crops for

  11. Model-Based Sensor Placement for Component Condition Monitoring and Fault Diagnosis in Fossil Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mobed, Parham [Texas Tech Univ., Lubbock, TX (United States); Pednekar, Pratik [West Virginia Univ., Morgantown, WV (United States); Bhattacharyya, Debangsu [West Virginia Univ., Morgantown, WV (United States); Turton, Richard [West Virginia Univ., Morgantown, WV (United States); Rengaswamy, Raghunathan [Texas Tech Univ., Lubbock, TX (United States)

    2016-01-29

    Design and operation of energy producing, near “zero-emission” coal plants has become a national imperative. This report on model-based sensor placement describes a transformative two-tier approach to identify the optimum placement, number, and type of sensors for condition monitoring and fault diagnosis in fossil energy system operations. The algorithms are tested on a high fidelity model of the integrated gasification combined cycle (IGCC) plant. For a condition monitoring network, whether equipment should be considered at a unit level or a systems level depends upon the criticality of the process equipment, its likeliness to fail, and the level of resolution desired for any specific failure. Because of the presence of a high fidelity model at the unit level, a sensor network can be designed to monitor the spatial profile of the states and estimate fault severity levels. In an IGCC plant, besides the gasifier, the sour water gas shift (WGS) reactor plays an important role. In view of this, condition monitoring of the sour WGS reactor is considered at the unit level, while a detailed plant-wide model of gasification island, including sour WGS reactor and the Selexol process, is considered for fault diagnosis at the system-level. Finally, the developed algorithms unify the two levels and identifies an optimal sensor network that maximizes the effectiveness of the overall system-level fault diagnosis and component-level condition monitoring. This work could have a major impact on the design and operation of future fossil energy plants, particularly at the grassroots level where the sensor network is yet to be identified. In addition, the same algorithms developed in this report can be further enhanced to be used in retrofits, where the objectives could be upgrade (addition of more sensors) and relocation of existing sensors.

  12. A Vibration-Based MEMS Piezoelectric Energy Harvester and Power Conditioning Circuit

    Directory of Open Access Journals (Sweden)

    Hua Yu

    2014-02-01

    Full Text Available This paper presents a micro-electro-mechanical system (MEMS piezoelectric power generator array for vibration energy harvesting. A complete design flow of the vibration-based energy harvester using the finite element method (FEM is proposed. The modal analysis is selected to calculate the resonant frequency of the harvester, and harmonic analysis is performed to investigate the influence of the geometric parameters on the output voltage. Based on simulation results, a MEMS Pb(Zr,TiO3 (PZT cantilever array with an integrated large Si proof mass is designed and fabricated to improve output voltage and power. Test results show that the fabricated generator, with five cantilever beams (with unit dimensions of about 3 × 2.4 × 0.05 mm3 and an individual integrated Si mass dimension of about 8 × 12.4 × 0.5 mm3, produces a output power of 66.75 μW, or a power density of 5.19 μW∙mm−3∙g−2 with an optimal resistive load of 220 kΩ from 5 m/s2 vibration acceleration at its resonant frequency of 234.5 Hz. In view of high internal impedance characteristic of the PZT generator, an efficient autonomous power conditioning circuit, with the function of impedance matching, energy storage and voltage regulation, is then presented, finding that the efficiency of the energy storage is greatly improved and up to 64.95%. The proposed self-supplied energy generator with power conditioning circuit could provide a very promising complete power supply solution for wireless sensor node loads.

  13. A vibration-based MEMS piezoelectric energy harvester and power conditioning circuit.

    Science.gov (United States)

    Yu, Hua; Zhou, Jielin; Deng, Licheng; Wen, Zhiyu

    2014-02-19

    This paper presents a micro-electro-mechanical system (MEMS) piezoelectric power generator array for vibration energy harvesting. A complete design flow of the vibration-based energy harvester using the finite element method (FEM) is proposed. The modal analysis is selected to calculate the resonant frequency of the harvester, and harmonic analysis is performed to investigate the influence of the geometric parameters on the output voltage. Based on simulation results, a MEMS Pb(Zr,Ti)O3 (PZT) cantilever array with an integrated large Si proof mass is designed and fabricated to improve output voltage and power. Test results show that the fabricated generator, with five cantilever beams (with unit dimensions of about 3 × 2.4 × 0.05 mm3) and an individual integrated Si mass dimension of about 8 × 12.4 × 0.5 mm3, produces a output power of 66.75 μW, or a power density of 5.19 μW∙mm-3∙g-2 with an optimal resistive load of 220 kΩ from 5 m/s2 vibration acceleration at its resonant frequency of 234.5 Hz. In view of high internal impedance characteristic of the PZT generator, an efficient autonomous power conditioning circuit, with the function of impedance matching, energy storage and voltage regulation, is then presented, finding that the efficiency of the energy storage is greatly improved and up to 64.95%. The proposed self-supplied energy generator with power conditioning circuit could provide a very promising complete power supply solution for wireless sensor node loads.

  14. Second-Order Necessary Optimality Conditions for Some State-Constrained Control Problems of Semilinear Elliptic Equations

    International Nuclear Information System (INIS)

    Casas, E.; Troeltzsch, F.

    1999-01-01

    In this paper we are concerned with some optimal control problems governed by semilinear elliptic equations. The case of a boundary control is studied. We consider pointwise constraints on the control and a finite number of equality and inequality constraints on the state. The goal is to derive first- and second-order optimality conditions satisfied by locally optimal solutions of the problem

  15. Study of Piezoelectric Vibration Energy Harvester with non-linear conditioning circuit using an integrated model

    Science.gov (United States)

    Manzoor, Ali; Rafique, Sajid; Usman Iftikhar, Muhammad; Mahmood Ul Hassan, Khalid; Nasir, Ali

    2017-08-01

    Piezoelectric vibration energy harvester (PVEH) consists of a cantilever bimorph with piezoelectric layers pasted on its top and bottom, which can harvest power from vibrations and feed to low power wireless sensor nodes through some power conditioning circuit. In this paper, a non-linear conditioning circuit, consisting of a full-bridge rectifier followed by a buck-boost converter, is employed to investigate the issues of electrical side of the energy harvesting system. An integrated mathematical model of complete electromechanical system has been developed. Previously, researchers have studied PVEH with sophisticated piezo-beam models but employed simplistic linear circuits, such as resistor, as electrical load. In contrast, other researchers have worked on more complex non-linear circuits but with over-simplified piezo-beam models. Such models neglect different aspects of the system which result from complex interactions of its electrical and mechanical subsystems. In this work, authors have integrated the distributed parameter-based model of piezo-beam presented in literature with a real world non-linear electrical load. Then, the developed integrated model is employed to analyse the stability of complete energy harvesting system. This work provides a more realistic and useful electromechanical model having realistic non-linear electrical load unlike the simplistic linear circuit elements employed by many researchers.

  16. Enhancement of low energy particle flux around plasmapause under quiet geomagnetic condition

    Science.gov (United States)

    Lee, J.

    2016-12-01

    Plasmapause is the boundary of the plasmaspheric region where cold plasma is dominant. In this boundary, the plasma density shows depletion to 1 10 on direction from the plasmasphere to magnetosphere and changes composition of energy distribution of particle. Some previous study provides that the location of the plasmapause expand beyond geosynchronous orbit under the quiet geomagnetic conditions. In this work, we study the changed characteristic of particle flux around the plasmapause using measurement from Van Allen Probes. On 23 April 2013, the satellites observed simultaneously proton and electron fluxes enhancement with E > 100 eV. During 12 hours prior to this event, the geomagnetic conditions were very quiet, Kp < 1, and geomagnetic storm did not occur. This event maintain for 15 minutes and only proton flux decrease rapidly in the magnetosphere. In this period SYM-H index enhanced abruptly in response to the impact of the dynamic pressure enhancement and AE index increased gradually up to about 200 nT. Electric field started to perturb in coincidence with enhancement of particle flux from the plasmapause. To explain the variation of low energy particle flux we will compare kinetic property of low energy particle by using velocity space distribution function at region of inner and outer boundary of the plasmapause.

  17. Multifunctional voltage source inverter for renewable energy integration and power quality conditioning.

    Science.gov (United States)

    Dai, NingYi; Lam, Chi-Seng; Zhang, WenChen

    2014-01-01

    In order to utilize the energy from the renewable energy sources, power conversion system is necessary, in which the voltage source inverter (VSI) is usually the last stage for injecting power to the grid. It is an economical solution to add the function of power quality conditioning to the grid-connected VSI in the low-voltage distribution system. Two multifunctional VSIs are studied in this paper, that is, inductive-coupling VSI and capacitive-coupling VSI, which are named after the fundamental frequency impedance of their coupling branch. The operation voltages of the two VSIs are compared when they are used for renewable energy integration and power quality conditioning simultaneously. The operation voltage of the capacitive-coupling VSI can be set much lower than that of the inductive-coupling VSI when reactive power is for compensating inductive loads. Since a large portion of the loads in the distribution system are inductive, the capacitive-coupling VSI is further studied. The design and control method of the multifunctional capacitive-coupling VSI are proposed in this paper. Simulation and experimental results are provided to show its validity.

  18. Energy savings potential of a hybrid desiccant dehumidification air conditioning system in Beirut

    International Nuclear Information System (INIS)

    Ghali, Kamel

    2008-01-01

    In this work, the transient performance of a hybrid desiccant vapor compression air conditioning system is numerically simulated for the ambient conditions of Beirut. The main feature of this hybrid system is that the regenerative heat needed by the desiccant wheel is partly supplied by the condenser dissipated heat while the rest is supplied by an auxiliary gas heater. The hybrid air conditioning system of the present study replaces a 23 kW vapor compression unit for a typical office in Beirut characterized by a high latent load. The vapor compression subsystem size in the hybrid air conditioning system is reduced to 15 kW at the peak load when the regeneration temperature was fixed at 75 deg. C. Also the sensible heat ratio of the combined hybrid system increased from 0.47 to 0.73. Based on hour by hour simulation studies for a wide range of recorded ambient conditions of Beirut city, this paper predicts the annual energy consumption of the hybrid system in comparison with the conventional vapor compression system for the entire cooling season. The annual running costs savings for the hybrid system is 418.39 USD for a gas cost price of 0.141 USD/kg. The pay back period of the hybrid system is less than five years when the initial cost of the hybrid air conditioning system priced an additional 1712.00 USD. Hence, for a 20-year life cycle, the life cycle savings of the hybrid air conditioning system are 4295.19 USD

  19. On thermoeconomics of energy systems at variable load conditions: Integrated optimization of plant design and operation

    International Nuclear Information System (INIS)

    Piacentino, A.; Cardona, F.

    2007-01-01

    Thermoeconomics has been assuming a growing role among the disciplines oriented to the analysis of energy systems, its different methodologies allowing solution of problems in the fields of cost accounting, plant design optimisation and diagnostic of malfunctions. However, the thermoeconomic methodologies as such are particularly appropriate to analyse large industrial systems at steady or quasi-steady operation, but they can be hardly applied to small to medium scale units operating in unsteady conditions to cover a variable energy demand. In this paper, the fundamentals of thermoeconomics for systems operated at variable load are discussed, examining the cost formation process and, separately, the cost fractions related to capital depreciation (which require additional distinctions with respect to plants in steady operation) and to exergy consumption. The relevant effects of the efficiency penalty due to off design operation on the exergetic cost of internal flows are also examined. An original algorithm is proposed for the integrated optimization of plant design and operation based on an analytical solution by the Lagrange multipliers method and on a multi-objective decision function, expressed either in terms of net cash flow or primary energy saving. The method is suitable for application in complex energy systems, such as 'facilities of components of a same product' connected to external networks for power or heat distribution. For demonstrative purposes, the proposed thermoeconomically aided optimization is performed for a grid connected trigeneration system to be installed in a large hotel

  20. Novel electrical energy storage system based on reversible solid oxide cells: System design and operating conditions

    Science.gov (United States)

    Wendel, C. H.; Kazempoor, P.; Braun, R. J.

    2015-02-01

    Electrical energy storage (EES) is an important component of the future electric grid. Given that no other widely available technology meets all the EES requirements, reversible (or regenerative) solid oxide cells (ReSOCs) working in both fuel cell (power producing) and electrolysis (fuel producing) modes are envisioned as a technology capable of providing highly efficient and cost-effective EES. However, there are still many challenges and questions from cell materials development to system level operation of ReSOCs that should be addressed before widespread application. This paper presents a novel system based on ReSOCs that employ a thermal management strategy of promoting exothermic methanation within the ReSOC cell-stack to provide thermal energy for the endothermic steam/CO2 electrolysis reactions during charging mode (fuel producing). This approach also serves to enhance the energy density of the stored gases. Modeling and parametric analysis of an energy storage concept is performed using a physically based ReSOC stack model coupled with thermodynamic system component models. Results indicate that roundtrip efficiencies greater than 70% can be achieved at intermediate stack temperature (680 °C) and elevated stack pressure (20 bar). The optimal operating condition arises from a tradeoff between stack efficiency and auxiliary power requirements from balance of plant hardware.

  1. Online Air-Conditioning Energy Management under Coalitional Game Framework in Smart Community

    Directory of Open Access Journals (Sweden)

    Wei Fan

    2016-08-01

    Full Text Available Motivated by the potential ability of air conditioning (A/C units in demand response, this paper explores how to utilize A/C units to increase the profit of a smart community. A coalitional game between the households and the load serving entity (LSE in a smart community is studied, where the LSE joins by selling renewable energy to householders and providing an energy saving service to them through an A/C controller. The A/C controller is designed to reduce the amount of electricity purchased from the main grid by controlling A/C units. An online A/C energy management algorithm is developed, based on Lyapunov optimization, that considers both the A/C energy consumption and the thermal comfort level of consumers. In order to quantify the contribution of A/C units, the Shapley value is adopted for distribution of the reward among the participating householders and the LSE, based on their contribution. The simulation result verifies the effectiveness of the proposed coalitional game for a smart community and the algorithm for A/C.

  2. Application of solar energy in heating and cooling of residential buildings under Central Asian conditions

    Directory of Open Access Journals (Sweden)

    Usmonov Shukhrat Zaurovich

    2014-04-01

    Full Text Available Solar radiation is the main source of thermal energy for almost all the processes developing in the atmosphere, hydrosphere, and biosphere. The total duration of sunshine in Tajikistan ranges from 2100 to 3170 hours per year. Solar collectors can be mounted on the roof of a house after its renovation and modernization. One square meter of surface area in Central Asia accounts for up to 1600 kW/h of solar energy gain, whilst the average gain is 1200 kW/h. Active solar thermal systems are able to collect both low- and high-temperature heat. Active systems require the use of special engineering equipment for the collection, storage, conversion and distribution of heat, while a low-grade system is based on the principle of using a flat solar collector. The collector is connected to the storage tank for storing the heated water, gas, etc. The water temperature is in the range 50-60 °C. For summer air conditioning in hot climates, absorption-based solar installations with open evaporating solution are recommended. The UltraSolar PRO system offers an opportunity to make a home independent of traditional electricity. Combining Schneider Electric power generation and innovative energy storage technology results in an independent power supply. Traditional power supply systems can be short-lived since they store energy in lead-acid batteries which have a negligible lifetime. Lead-acid batteries operate in a constant charge-discharge mode, require specific conditions for best performance and can fail suddenly. Sudden failure of lead acid batteries, especially in winter in the northern part of Tajikistan, completely disables the heating system of a building. Instead, it is recommended to use industrial lithium-ion batteries, which have a significantly longer life and reliability compared to lead-acid type. UltraSolar PRO are ideal and provide a complete package, low noise and compact lithium-ion power supply.

  3. The importance of moisture buffering for indoor climate and energy conditions of buildings

    DEFF Research Database (Denmark)

    Rode, Carsten; Grau, Karl

    2007-01-01

    A new Nordic test method specifies a test protocol for determination of the so-called Moisture Buffer Value (MBV) of building materials. But how important is moisture buffering to determine the indoor humidity condition of buildings? The paper will present the new MBV-definition. Although...... buffering to save energy by reducing the requirement for ventilation in periods, and still maintain the same quality of the indoor climate? The paper will outline some possibilities for analytical/numerical calculations, and will answer some of the posed questions on the probable benefit of taking moisture...

  4. Topology and Singularities in Cosmological Spacetimes Obeying the Null Energy Condition

    Science.gov (United States)

    Galloway, Gregory J.; Ling, Eric

    2018-06-01

    We consider globally hyperbolic spacetimes with compact Cauchy surfaces in a setting compatible with the presence of a positive cosmological constant. More specifically, for 3 + 1 dimensional spacetimes which satisfy the null energy condition and contain a future expanding compact Cauchy surface, we establish a precise connection between the topology of the Cauchy surfaces and the occurrence of past singularities. In addition to the Penrose singularity theorem, the proof makes use of some recent advances in the topology of 3-manifolds and of certain fundamental existence results for minimal surfaces.

  5. Approximate albedo boundary conditions for energy multigroup X,Y-geometry discrete ordinates nuclear global calculations

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Davi J.M.; Nunes, Carlos E.A.; Alves Filho, Hermes; Barros, Ricardo C., E-mail: davijmsilva@yahoo.com.br, E-mail: ceanunes@yahoo.com.br, E-mail: rcbarros@pq.cnpq.br [Secretaria Municipal de Educacao de Itaborai, RJ (Brazil); Universidade Estacio de Sa (UNESA), Rio de Janeiro, RJ (Brazil); Universidade do Estado do Rio de Janeiro (UERJ), Novra Friburgo, RJ (Brazil). Instituto Politecnico. Departamento de Modelagem Computacional

    2017-11-01

    Discussed here is the accuracy of approximate albedo boundary conditions for energy multigroup discrete ordinates (S{sub N}) eigenvalue problems in two-dimensional rectangular geometry for criticality calculations in neutron fission reacting systems, such as nuclear reactors. The multigroup (S{sub N}) albedo matrix substitutes approximately the non-multiplying media around the core, e.g., baffle and reflector, as we neglect the transverse leakage terms within these non-multiplying regions. Numerical results to a typical model problem are given to illustrate the accuracy versus the computer running time. (author)

  6. Modeling of Energy-saving System of Conditioning Mine Air for Shallow Underground Mines

    Science.gov (United States)

    Nikolaev, Alexandr; Miftakhov, Timur; Nikolaeva, Evgeniya

    2017-11-01

    Mines of Verkhnekamsk potassium-magnesium salt deposit in Perm Krai can be subsumed under shallow mines (depth less than 500 meters). At the present moment in shallow underground mines the are problem of condensate formation in large quantities, when ventilation warm seasons of the year. This problem is more actual for salt mine, where during contact between water and potassium-magnesium ore produced electrolyte, which give rise wear of equipment. For prevent/quantity reduction condensate formation in mine used system of conditioning (refrigerating and dehumidifying) mine air (ACS). However, application this system is limited by reason of tremendous costs of electric energy for their work.

  7. Energy balance of a sparse coniferous high-latitude forest under winter conditions

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Batchvarova, E.; Bruin, H.A.R. de

    2001-01-01

    was simulated for a three month period. For conditions with a cloud cover of less than 7 oktas good agreement between model predictions and measurements were found. For cloud cover 7 and 8 oktas a considerable spread can be observed. To apply the proposed energy balance model, the global radiation must......Measurements carried out in Northern Finland on radiation and turbulent fluxes over a sparse, sub-arctic boreal forest with snow covered ground were analysed. The measurements represent late winter conditions characterised by low solar elevation angles. During the experiment (12-24 March 1997) day...... and night were about equally long. At low solar elevation angles the forest shades most of the snow surface. Therefore an important part of the radiation never reaches the snow surface but is absorbed by the forest. The sensible heat flux above the forest was fairly large, reaching more than 100 W m(-2...

  8. Galerkin methods for Boltzmann-Poisson transport with reflection conditions on rough boundaries

    Science.gov (United States)

    Morales Escalante, José A.; Gamba, Irene M.

    2018-06-01

    We consider in this paper the mathematical and numerical modeling of reflective boundary conditions (BC) associated to Boltzmann-Poisson systems, including diffusive reflection in addition to specularity, in the context of electron transport in semiconductor device modeling at nano scales, and their implementation in Discontinuous Galerkin (DG) schemes. We study these BC on the physical boundaries of the device and develop a numerical approximation to model an insulating boundary condition, or equivalently, a pointwise zero flux mathematical condition for the electron transport equation. Such condition balances the incident and reflective momentum flux at the microscopic level, pointwise at the boundary, in the case of a more general mixed reflection with momentum dependant specularity probability p (k →). We compare the computational prediction of physical observables given by the numerical implementation of these different reflection conditions in our DG scheme for BP models, and observe that the diffusive condition influences the kinetic moments over the whole domain in position space.

  9. High-energy intermediates in protein unfolding characterized by thiol labeling under nativelike conditions.

    Science.gov (United States)

    Malhotra, Pooja; Udgaonkar, Jayant B

    2014-06-10

    A protein unfolding reaction usually appears to be so dominated by a large free energy barrier that identifying and characterizing high-energy intermediates and, hence, dissecting the unfolding reaction into multiple structural transitions have proven to be a challenge. In particular, it has been difficult to identify any detected high-energy intermediate with the dry (DMG) and wet (WMG) molten globules that have been implicated in the unfolding reactions of at least some proteins. In this study, a native-state thiol labeling methodology was used to identify high-energy intermediates, as well as to delineate the barriers to the disruption of side chain packing interactions and to site-specific solvent exposure in different regions of the small protein, single-chain monellin (MNEI). Labeling studies of four single-cysteine-containing variants of MNEI have identified three high-energy intermediates, populated to very low extents under nativelike conditions. A significant dispersion in the opening rates of the cysteine side chains has allowed multiple steps, leading to the loss of side chain packing, to be resolved temporally. A detailed structural analysis of the positions of the four cysteine residue positions, which are buried to different depths within the protein, has suggested a direct correlation with the structure of a DMG, detected in previous studies. It is observed that side chain packing within the core of the protein is maintained, while that at the surface is disrupted, in the DMG. The core of the protein becomes solvent-exposed only in a WMG populated after the rate-limiting step of unfolding at high denaturant concentrations.

  10. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  11. Staged Inference using Conditional Deep Learning for energy efficient real-time smart diagnosis.

    Science.gov (United States)

    Parsa, Maryam; Panda, Priyadarshini; Sen, Shreyas; Roy, Kaushik

    2017-07-01

    Recent progress in biosensor technology and wearable devices has created a formidable opportunity for remote healthcare monitoring systems as well as real-time diagnosis and disease prevention. The use of data mining techniques is indispensable for analysis of the large pool of data generated by the wearable devices. Deep learning is among the promising methods for analyzing such data for healthcare applications and disease diagnosis. However, the conventional deep neural networks are computationally intensive and it is impractical to use them in real-time diagnosis with low-powered on-body devices. We propose Staged Inference using Conditional Deep Learning (SICDL), as an energy efficient approach for creating healthcare monitoring systems. For smart diagnostics, we observe that all diagnoses are not equally challenging. The proposed approach thus decomposes the diagnoses into preliminary analysis (such as healthy vs unhealthy) and detailed analysis (such as identifying the specific type of cardio disease). The preliminary diagnosis is conducted real-time with a low complexity neural network realized on the resource-constrained on-body device. The detailed diagnosis requires a larger network that is implemented remotely in cloud and is conditionally activated only for detailed diagnosis (unhealthy individuals). We evaluated the proposed approach using available physiological sensor data from Physionet databases, and achieved 38% energy reduction in comparison to the conventional deep learning approach.

  12. Numerical analysis of an entire ceramic kiln under actual operating conditions for the energy efficiency improvement.

    Science.gov (United States)

    Milani, Massimo; Montorsi, Luca; Stefani, Matteo; Saponelli, Roberto; Lizzano, Maurizio

    2017-12-01

    The paper focuses on the analysis of an industrial ceramic kiln in order to improve the energy efficiency and thus the fuel consumption and the corresponding carbon dioxide emissions. A lumped and distributed parameter model of the entire system is constructed to simulate the performance of the kiln under actual operating conditions. The model is able to predict accurately the temperature distribution along the different modules of the kiln and the operation of the many natural gas burners employed to provide the required thermal power. Furthermore, the temperature of the tiles is also simulated so that the quality of the final product can be addressed by the modelling. Numerical results are validated against experimental measurements carried out on a real ceramic kiln during regular production operations. The developed numerical model demonstrates to be an efficient tool for the investigation of different design solutions for the kiln's components. In addition, a number of control strategies for the system working conditions can be simulated and compared in order to define the best trade off in terms of fuel consumption and product quality. In particular, the paper analyzes the effect of a new burner type characterized by internal heat recovery capability aimed at improving the energy efficiency of the ceramic kiln. The fuel saving and the relating reduction of carbon dioxide emissions resulted in the order of 10% when compared to the standard burner. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Bed turbulent kinetic energy boundary conditions for trapping efficiency and spatial distribution of sediments in basins.

    Science.gov (United States)

    Isenmann, Gilles; Dufresne, Matthieu; Vazquez, José; Mose, Robert

    2017-10-01

    The purpose of this study is to develop and validate a numerical tool for evaluating the performance of a settling basin regarding the trapping of suspended matter. The Euler-Lagrange approach was chosen to model the flow and sediment transport. The numerical model developed relies on the open source library OpenFOAM ® , enhanced with new particle/wall interaction conditions to limit sediment deposition in zones with favourable hydrodynamic conditions (shear stress, turbulent kinetic energy). In particular, a new relation is proposed for calculating the turbulent kinetic energy threshold as a function of the properties of each particle (diameter and density). The numerical model is compared to three experimental datasets taken from the literature and collected for scale models of basins. The comparison of the numerical and experimental results permits concluding on the model's capacity to predict the trapping of particles in a settling basin with an absolute error in the region of 5% when the sediment depositions occur over the entire bed. In the case of sediment depositions localised in preferential zones, their distribution is reproduced well by the model and trapping efficiency is evaluated with an absolute error in the region of 10% (excluding cases of particles with very low density).

  14. Optimal condition of torrefaction for high energy density solid fuel of fast growing tree species

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Hun; Na, Byeong-Il; Lee, Hyoung-Woo; Lee, Jae-Won [College of Agriculture and Life Sciences, Chonnam National University, Gwangju (Korea, Republic of); Ahn, Byoung-Jun [Korea Forest Research Institute, Seoul (Korea, Republic of)

    2015-08-15

    The torrefaction properties of Acacia (Acacia mangium) and Albasia (Paraserianthes falcataria) were investigated by response surface methodology. Torrefaction was performed at 220-280 .deg. C for 20-80 min depending on severity factor. Carbon content in the torrefied biomass increased with severity factor, whereas hydrogen and oxygen contents decreased both biomass. The calorific value of torrefied Acacia ranged from 20.03 to 21.60 MJ/kg, suggesting that the energy contained in the torrefied biomass increased by 5.09 to 13.62%, when compared with that in the untreated biomass. However, the calorific value of Albasia was relatively low, compared to that of torrefied Acacia. The weight loss of Albasia was higher than that of Acacia under a given torrefaction condition. The reaction temperature for torrefaction was an important factor to obtain high energy yield, whereas the effect of time was considerable lower. High temperature and short torrefaction time is required to obtain the highest energy yield from torrefaction using Acacia and Albasia.

  15. Analysis of electric energy consumption of automatic milking systems in different configurations and operative conditions.

    Science.gov (United States)

    Calcante, Aldo; Tangorra, Francesco M; Oberti, Roberto

    2016-05-01

    Automatic milking systems (AMS) have been a revolutionary innovation in dairy cow farming. Currently, more than 10,000 dairy cow farms worldwide use AMS to milk their cows. Electric consumption is one of the most relevant and uncontrollable operational cost of AMS, ranging between 35 and 40% of their total annual operational costs. The aim of the present study was to measure and analyze the electric energy consumption of 4 AMS with different configurations: single box, central unit featuring a central vacuum system for 1 cow unit and for 2 cow units. The electrical consumption (daily consumption, daily consumption per cow milked, consumption per milking, and consumption per 100L of milk) of each AMS (milking unit + air compressor) was measured using 2 energy analyzers. The measurement period lasted 24h with a sampling frequency of 0.2Hz. The daily total energy consumption (milking unit + air compressor) ranged between 45.4 and 81.3 kWh; the consumption per cow milked ranged between 0.59 and 0.99 kWh; the consumption per milking ranged between 0.21 and 0.33 kWh; and the consumption per 100L of milk ranged between 1.80 to 2.44 kWh according to the different configurations and operational contexts considered. Results showed that AMS electric consumption was mainly conditioned by farm management rather than machine characteristics/architectures. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Starting the universe: Stable violation of the null energy condition and non-standard cosmologies

    International Nuclear Information System (INIS)

    Creminelli, P.; Luty, M.A.; Nicolis, A.; Senatore, L.

    2006-06-01

    We present a consistent effective theory that violates the null energy condition (NEC) without developing any instabilities or other pathological features. The model is the ghost condensate with the global shift symmetry softly broken by a potential. We show that this system can drive a cosmological expansion with H-dot > 0. Demanding the absence of instabilities in this model requires H-dot or approx. H 2 . We then construct a general low-energy effective theory that describes scalar fluctuations about an arbitrary FRW background, and argue that the qualitative features found in our model are very general for stable systems that violate the NEC. Violating the NEC allows dramatically non- standard cosmological histories. To illustrate this, we construct an explicit model in which the expansion of our universe originates from an asymptotically flat state in the past, smoothing out the big-bang singularity within control of a low- energy effective theory. This gives an interesting alternative to standard inflation for solving the horizon problem. We also construct models in which the present acceleration has w < -1; a periodic ever-expanding universe; and a model with a smooth 'bounce' connecting a contracting and expanding phase. (author)

  17. Optimization of Design Parameters and Operating Conditions of Electrochemical Capacitors for High Energy and Power Performance

    Science.gov (United States)

    Ike, Innocent S.; Sigalas, Iakovos; Iyuke, Sunny E.

    2017-03-01

    Theoretical expressions for performance parameters of different electrochemical capacitors (ECs) have been optimized by solving them using MATLAB scripts as well as via the MATLAB R2014a optimization toolbox. The performance of the different kinds of ECs under given conditions was compared using theoretical equations and simulations of various models based on the conditions of device components, using optimal values for the coefficient associated with the battery-kind material ( K BMopt) and the constant associated with the electrolyte material ( K Eopt), as well as our symmetric electric double-layer capacitor (EDLC) experimental data. Estimation of performance parameters was possible based on values for the mass ratio of electrodes, operating potential range ratio, and specific capacitance of electrolyte. The performance of asymmetric ECs with suitable electrode mass and operating potential range ratios using aqueous or organic electrolyte at appropriate operating potential range and specific capacitance was 2.2 and 5.56 times greater, respectively, than for the symmetric EDLC and asymmetric EC using the same aqueous electrolyte, respectively. This enhancement was accompanied by reduced cell mass and volume. Also, the storable and deliverable energies of the asymmetric EC with suitable electrode mass and operating potential range ratios using the proper organic electrolyte were 12.9 times greater than those of the symmetric EDLC using aqueous electrolyte, again with reduced cell mass and volume. The storable energy, energy density, and power density of the asymmetric EDLC with suitable electrode mass and operating potential range ratios using the proper organic electrolyte were 5.56 times higher than for a similar symmetric EDLC using aqueous electrolyte, with cell mass and volume reduced by a factor of 1.77. Also, the asymmetric EDLC with the same type of electrode and suitable electrode mass ratio, working potential range ratio, and proper organic electrolyte

  18. The development of the Kozloduy NPP in the conditions of liberalized energy market

    International Nuclear Information System (INIS)

    Ivanov, A.

    2003-01-01

    The paper discusses specificities of the energy sector as a business system in the condition of liberalized energy market. The government influence the business system through the rate of economical stability and and possibility for prognosis, as well as through the direct influence of the field government institutions on the process of the development of the economical structures. The finance system influences the government ability to support and lead the industrial development. Two main system types are known: decentralized management (in countries with developed stock markets and a system for entrusting of activities on contract basis) and centralized (the success of the policy is connected with the success of the economical growth). Another aspect of the management in a business environment is the procedure of decision making for the firm policy formation and applying of a model for firm development. The transition to liberalized market means a significant limitation of the role of the government, which in the Bulgarian case should replace the state control system in real time and the state credit. Since the low amortization the electricity production has low cost price and possibility for generation of rehabilitation funds, i.e for extension of the service life on minimal cost. The funds can be used for improvement of the stability of the sector. For the purposes of the analysis made, system parameters are reviewed with regard of the market realities. The Balkan region is semi-closed energy system 40% of the electricity is imported from several countries: Bulgaria, Romania, Serbia and Albania. The prices are greatly influenced by the moment conditions of the electricity production and industry in the region. The policy should be oriented in two directions: expectations for interests in the privatization of electric energy companies and appropriate strategy for preservation of the market positions. The analysis of the factors influencing nuclear energy

  19. Simulation of tree shade impacts on residential energy use for space conditioning in Sacramento

    Science.gov (United States)

    Simpson, J. R.; McPherson, E. G.

    Tree shade reduces summer air conditioning demand and increases winter heating load by intercepting solar energy that would otherwise heat the shaded structure. We evaluate the magnitude of these effects here for 254 residential properties participating in a utility sponsored tree planting program in Sacramento, California. Tree and building characteristics and typical weather data are used to model hourly shading and energy used for space conditioning for each building for a period of one year. There were an average of 3.1 program trees per property which reduced annual and peak (8 h average from 1 to 9 p.m. Pacific Daylight Time) cooling energy use 153 kWh (7.1%) and 0.08 kW (2.3%) per tree, respectively. Annual heating load increased 0.85 GJ (0.80 MBtu, 1.9%) per tree. Changes in cooling load were smaller, but percentage changes larger, for newer buildings. Averaged over all homes, annual cooling savings of 15.25 per tree were reduced by a heating penalty of 5.25 per tree, for net savings of 10.00 per tree from shade. We estimate an annual cooling penalty of 2.80 per tree and heating savings of 6.80 per tree from reduced wind speed, for a net savings of 4.00 per tree, and total annual savings of 14.00 per tree (43.00 per property). Results are found to be consistent with previous simulations and the limited measurements available.

  20. Modeling the water-energy nexus under changing energy market and climate conditions: a case study in the Italian Alps

    Science.gov (United States)

    Denaro, Simona; Anghileri, Daniela; Castelletti, Andrea; Fumagalli, Elena; Giuliani, Matteo

    2015-04-01

    Climate change and growing population are expected to severely affect freshwater availability by the end of 21th century. Many river basins, especially in the Mediterranean region, are likely to become more prone to periods of reduced water supply, risking considerable impacts on the society, the environment, and the economy, thus emphasizing the need to rethink the way water resources are distributed, managed, and used at the regional and river basin scale. This paradigm shift will be essential to cope with the undergoing global change, characterized by growing water demands and by increasingly uncertain hydrologic regimes. Most of the literature traditionally focused on predicting the impacts of climate change on water resources, while our understanding of the human footprint on the hydrological cycle is limited. For example, changes in the operation of the Alpine hydropower reservoirs induced by socio-economic drivers (e.g., development of renewable energy) have been already observed over the last few years and have produced relevant impacts on multiple water uses due to the altered distribution of water volumes in time and space. Modeling human decisions as well as the links between society and environmental systems becomes key to develop reliable projections on the co-evolution of the coupled human-water systems and deliver robust adaptation strategies. This work contributes a preliminary model-based analysis of the behaviour of hydropower operators under changing energy market and climate conditions. The proposed approach is developed for the San Giacomo-Cancano reservoir system located in the Lake Como catchment. The identification of the current operating policy is supported by input variable selection methods to select the most relevant hydrological and market based drivers to explain the observed release time series. The identified model is then simulated under a set of future scenarios, accounting for both climate and socio-economic change (e

  1. Development of energy-saving technologies providing comfortable microclimate conditions for mining

    Directory of Open Access Journals (Sweden)

    Б. П. Казаков

    2017-03-01

    Full Text Available The paper contains analysis of natural and technogenic factors influencing properties of mine atmosphere, defining level of mining safety and probability of emergencies. Main trends in development of energy-saving technologies providing comfortable microclimate conditions are highlighted. A complex of methods and mathematical models has been developed to carry out aerologic and thermophysical calculations. Main ways of improvement for existing calculation methods of stationary and non-stationary air distribution have been defined: use of ejection draught sources to organize recirculation ventilation; accounting of depression losses at working intersections; inertance impact of  air streams and mined-out spaces for modeling transitory emergency scenarios. Based on the calculation algorithm of airflow rate distribution in the mine network, processing method has been developed for the results of air-depressive surveys under conditions of data shortage. Processes of dust transfer have been modeled in view of its coagulation and settlement, as well as interaction with water drops in case of wet dust prevention. A method to calculate intensity of water evaporation and condensation has been suggested, which allows to forecast time, duration and quantity of precipitation and its migration inside the mine during winter season. Solving the problem of heat exchange between mine airflow and timbering of the ventilation shaft in a conjugation formulation permits to estimate depression value of natural draught and conditions of convective balance between air streams. Normalization of microclimatic parameters for mine atmosphere is forecasted for the use of heat-exchange units either heating or cooling and dehumidifying ventilation air. Algorithms are presented that permit to minimize ventilation energy demands at the stages of mine design and exploitation.

  2. Automobile air-conditioning its energy and environmental impact; La climatisation automobile impact energetique et environnemental

    Energy Technology Data Exchange (ETDEWEB)

    Barbusse, St.; Gagnepain, L.

    2003-05-01

    Over the last three decades, automobile manufacturers have made a lot of progress in specific fuel consumption and engine emissions of pollutants. Yet the impact of these improvements on vehicle consumption has been limited by increased dynamic performances (maxi-mum speed, torque), increased safety (power steering and power brakes) and increased comfort (noise and vibration reduction, electric windows and thermal comfort). Because of this, the real CO{sub 2}-emission levels in vehicles is still high in a context where road transport is a major factor in the balance sheet of greenhouse gas emissions, thus in complying with the inter-national climate convention. Although European, Japanese and Korean manufacturers signed an important agreement with the European Commission for voluntarily reducing CO{sub 2} emissions from their vehicles, with a weighted average emission goal by sales of 140 grams per km on the MVEG approval cycle by 2008, it has to be noted that the European procedures for measuring fuel consumption and CO{sub 2} emissions do not take accessories into account, especially air-condition ng (A/C). The big dissemination of this equipment recognized as a big energy consumer and as using a refrigerant with a high global warming potential ed ADEME to implement a set of assessments of A/C's energy and environmental impact. In particular these assessments include studies of vehicle equipment rates, analyses of impact on fuel consumption as well as regulated pollutant emissions in the exhaust, a characterization of the refrigerant leakage levels and an estimate of greenhouse gas emissions for all air-conditioned vehicles. This leaflet summarizes the results of these actions. All of these studies and additional data are presented in greater detail in the document,-'Automobile Air-conditioning' (ADEME reference no. 4985). (author)

  3. Energy performance and optimal control of air-conditioned buildings with envelopes enhanced by phase change materials

    International Nuclear Information System (INIS)

    Zhu Na; Wang Shengwei; Ma Zhenjun; Sun Yongjun

    2011-01-01

    Highlights: → Impact of PCM on the energy consumption and peak load demand as well as electricity cost of air-conditioned buildings. → Impact of load shifting control on energy consumption, peak load and electricity cost of air-conditioned PCM buildings. → Impact of demand limiting control on energy consumption, peak load and electricity cost of air-conditioned PCM buildings. → Energy/cost effects of different control strategies and use of PCM in energy-plus-demand-based pricing policy. → Energy/cost effects of different control strategies and use of PCM in time-based pricing policy. - Abstract: Studies are conducted to investigate the impacts of shape-stabilized phase change material (SSPCM) and different control strategies on the energy consumption and peak load demand as well as electricity cost of building air-conditioning systems at typical summer conditions in two climates (subtropical and dry continental climates). An office building using a typical variable air volume (VAV) air-conditioning system was selected and simulated as the reference building in this study. Its envelopes were enhanced by integrating the SSPCM layers into its walls while the air-conditioning system and other configurations of the building remained unchanged. The building system was tested under two typical weather conditions and two typical electricity pricing policies (i.e. time-based pricing and energy-plus-demand-based pricing). Test results show that the use of SSPCM in the building could reduce the building electricity cost significantly (over 11% in electricity cost reduction and over 20% in peak load reduction), under two pricing policies by using load shifting control and demand limiting control respectively. This paper presents the test results and the evaluation on the energy performance and the optimal control strategies of air-conditioned commercial buildings with envelopes enhanced by SSPCM.

  4. A smartphone-driven methodology for estimating physical activities and energy expenditure in free living conditions.

    Science.gov (United States)

    Guidoux, Romain; Duclos, Martine; Fleury, Gérard; Lacomme, Philippe; Lamaudière, Nicolas; Manenq, Pierre-Henri; Paris, Ludivine; Ren, Libo; Rousset, Sylvie

    2014-12-01

    This paper introduces a function dedicated to the estimation of total energy expenditure (TEE) of daily activities based on data from accelerometers integrated into smartphones. The use of mass-market sensors such as accelerometers offers a promising solution for the general public due to the growing smartphone market over the last decade. The TEE estimation function quality was evaluated using data from intensive numerical experiments based, first, on 12 volunteers equipped with a smartphone and two research sensors (Armband and Actiheart) in controlled conditions (CC) and, then, on 30 other volunteers in free-living conditions (FLC). The TEE given by these two sensors in both conditions and estimated from the metabolic equivalent tasks (MET) in CC served as references during the creation and evaluation of the function. The TEE mean gap in absolute value between the function and the three references was 7.0%, 16.4% and 2.7% in CC, and 17.0% and 23.7% according to Armband and Actiheart, respectively, in FLC. This is the first step in the definition of a new feedback mechanism that promotes self-management and daily-efficiency evaluation of physical activity as part of an information system dedicated to the prevention of chronic diseases. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. ENERGY AND CONSTRUCTION CONDITIONS OF THE EFFECTIVENESS OF APPAATUS FOR GENERAL CRYOTHERAPEUTIC IMPACT

    Directory of Open Access Journals (Sweden)

    A. U. Baranov

    2016-01-01

    Full Text Available Objectives. To evaluate the correspondence of construction and power consumption of Cryotherapeutic Complexes (CTC with technological conditions of effectiveness of the General Cryotherapeutic Impact (GCI. Methods. The associated analysis method used Cryotherapeutic Complexes (CTC construction and power consumption with technological conditions of effectiveness of the General Cryotherapeutic Impact (GCI. Results. An explanation for the discrepancy of observations of different researchers in differences in design and available power of the CTC is proposed. The technical operating characteristics of single-seat and multi-seat CTC are provided and these significant differences in apparatus of identical technological designation are illustrated. The proposed system of specific CTC characteristics is capable of unifying their basic structural and energy characteristics. Calculation of the specific characteristics of existing systems showed that between objects of the same designation, there are differences in value, which may be the cause of discrepancies in their therapeutic efficacy. All functional CPC have a cryostatting cooling capacity system deficit of between 8 and 75%. In multi-seat CPC cooling capacity deficit exceeds 50%, which excludes the possibility of obtaining a significant therapeutic effect, as is confirmed by the results of independent studies that show that the procedures in multi-seat CTC safeguards skin from frigorism only up to 14°C, while at the same time for effective OKV frigorism of the skin surface is necessary to a temperature of less than about 2°C. Prior to research on the effectiveness of OKV, it is necessary to assess the energy consumption conformity of cryotherapy equipment. Conclusion. For the successful implementation of OKV in medicine and sport, it is necessary to increase energy efficiency and optimise cryotherapeutic temperature control settings. A cryotheraputic complex should safeguard such physical

  6. Housing Conditions and the Use of Alternative Energy Sources in Households of Senior Citizens in Poland

    Directory of Open Access Journals (Sweden)

    Tomasz Zalega

    2017-07-01

    Full Text Available Aim/purpose - The article aims to show the housing situation, satisfaction with housing conditions and place of residence, and the use of renewable energy sources in urban households of Polish seniors. Design/methodology/approach - Direct research in the form of a survey questionnaire was carried out on a sample of 2537 households in 2014-2015 in ten Polish cities of various populations and sizes. In accordance with the research assumptions, the sample included persons over 65 years of age who took independent purchasing decisions in the market. In order to select the sample, the selective quota sampling procedure was used. The survey was conducted among participants of the University of the Third Age at state universities in: Warsaw, Kraków, Łódź, Poznań, Gdańsk, Katowice, Lublin, Białystok, Toruń and Wrocław, as well as among members of parochial clubs in parishes located in the Archdioceses of Warsaw, Kraków, Łódź, Białystok, Gdańsk, Katowice, Lublin, Poznań, Wrocław and the Dioceses of Warsaw-Praga and Toruń. Findings - The survey reveals that more than half of seniors' households are satisfied with both the place of residence and housing conditions. The use of RES in seniors' households looks slightly worse. Only 1.5% of all the surveyed households of persons aged 65+ invest in alternative energy sources to produce electricity and heat. Financial problems are the key barrier to the development of RES-related projects in their households. Research implications/limitations - Given the limited financial capacities, the study of housing conditions and the use of RES among people aged 65+ was confined solely to seniors' households in the largest Polish cities. In those households, a relatively low share of RES often results from inadequate technical conditions for the connection of RES installations. Rural households generate slightly more electricity and heat from RES Originality/value/contribution - This is one of the first

  7. Energy losses in mixed matrix superconducting wires under fast pulsed conditions

    International Nuclear Information System (INIS)

    Wollan, J.J.

    1976-01-01

    Energy losses have been measured on a set of mixed matrix (CuNi, Cu, NbTi) superconducting wires at B's up to 1.5 x 10 7 G/s. The losses have been measured as a function of wire diameter, twist pitch, maximum applied field, and B. Both static and dynamic losses were measured for a field applied perpendicularly to the wire axis. The dynamic losses were measured by slowly applying an external field to a sample and then causing the field to decay exponentially in roughly 1 ms to 10 ms. Under low B (9 kG) and B (10 6 G/s) conditions the hysteretic loss dominated. At high B (21 kG) and B (1.5 x 10 7 G/s) the matrix losses became dominant. The systematic variation of the losses with the mentioned parameters will be presented and will be compared to theoretical predictions

  8. Examination of the conditions of a broadening of the general tax for polluting activities to the intermediate energy consumptions, examination of the conditions of exoneration and attenuation for the energy uses in the industry

    International Nuclear Information System (INIS)

    Beaulinet, M.

    2000-05-01

    This document examines the conditions for a broadening of the general tax on polluting activities to the intermediate energy consumptions in order to reinforce the fight against greenhouse effect and to better master the energy consumption. It analyses the characteristics of each energy source with respect to the principle of a taxation of the consumptions. Finally, several scenarios are analyzed to show the advantage and drawbacks of such a system. A first evaluation and a preliminary tariffing are given. (J.S.)

  9. A generalized electron energy probability function for inductively coupled plasmas under conditions of nonlocal electron kinetics

    Science.gov (United States)

    Mouchtouris, S.; Kokkoris, G.

    2018-01-01

    A generalized equation for the electron energy probability function (EEPF) of inductively coupled Ar plasmas is proposed under conditions of nonlocal electron kinetics and diffusive cooling. The proposed equation describes the local EEPF in a discharge and the independent variable is the kinetic energy of electrons. The EEPF consists of a bulk and a depleted tail part and incorporates the effect of the plasma potential, Vp, and pressure. Due to diffusive cooling, the break point of the EEPF is eVp. The pressure alters the shape of the bulk and the slope of the tail part. The parameters of the proposed EEPF are extracted by fitting to measure EEPFs (at one point in the reactor) at different pressures. By coupling the proposed EEPF with a hybrid plasma model, measurements in the gaseous electronics conference reference reactor concerning (a) the electron density and temperature and the plasma potential, either spatially resolved or at different pressure (10-50 mTorr) and power, and (b) the ion current density of the electrode, are well reproduced. The effect of the choice of the EEPF on the results is investigated by a comparison to an EEPF coming from the Boltzmann equation (local electron kinetics approach) and to a Maxwellian EEPF. The accuracy of the results and the fact that the proposed EEPF is predefined renders its use a reliable alternative with a low computational cost compared to stochastic electron kinetic models at low pressure conditions, which can be extended to other gases and/or different electron heating mechanisms.

  10. Safety aspects of electric energy production and supplies in conditions of the Slovenske elektrarne, a.s

    International Nuclear Information System (INIS)

    Sip, M.; Danilak, M. et al.

    2005-01-01

    In this presentation author deals with safety aspects of electric energy production and supplies in conditions of the Slovenske elektrarne, a.s. Some terrorist attack and accidents are presented. Four video-sequences are included

  11. Wormholes in viable f(R) modified theories of gravity and weak energy condition

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovic, Petar [Universitaet Hamburg, II. Institut fuer Theoretische Physik, Hamburg (Germany); Sossich, Marko [University of Zagreb, Department of Physics, Faculty of Electrical Engineering and Computing, Zagreb (Croatia)

    2015-03-01

    In this work wormholes in viable f(R) gravity models are analyzed. We are interested in exact solutions for stress-energy tensor components depending on different shape and redshift functions. Several solutions of gravitational equations for different f(R) models are examined. The solutions found imply no need for exotic material, while this need is implied in the standard general theory of relativity. A simple expression for weak energy condition (WEC) violation near the throat is derived and analyzed. High curvature regime is also discussed, as well as the question of the highest possible values of the Ricci scalar for which the WEC is not violated near the throat, and corresponding functions are calculated for several models. The approach here differs from the one that has been common since no additional assumptions to simplify the equations have been made, and the functions in f(R) models are not considered to be arbitrary functions, but rather a feature of the theory that has to be evaluated on the basis of consistency with observations for the Solar System and cosmological evolution. Therefore in this work we show that the existence of wormholes without exotic matter is not only possible in simple arbitrary f(R) models, but also in models that are in accordance with empirical data. (orig.)

  12. Low-energy-electron interactions with DNA: approaching cellular conditions with atmospheric experiments

    International Nuclear Information System (INIS)

    Alizadeh, E.; Sanche, L.

    2014-01-01

    A novel technique has been developed to investigate low energy electron (LEE)-DNA interactions in the presence of small biomolecules (e.g., N 2 , O 2 , H 2 O) found near DNA in the cell nucleus, in order to simulate cellular conditions. In this technique, LEEs are emitted from a metallic surface exposed by soft X-rays and interact with DNA thin films at standard ambient temperature and pressure (SATP). Whereas atmospheric N 2 had little effect on the yields of LEE-induced single and double strand breaks, both O 2 and H 2 O considerably modified and increased such damage. The highest yields were obtained when DNA is embedded in a combined O 2 and H 2 O atmosphere. In this case, the amount of additional double strand breaks was supper-additive. The effect of modifying the chemical and physical stability of DNA by platinum-based chemotherapeutic agents (Pt-drugs) including cisplatin, carboplatin and oxaliplatin was also investigated with this technique. The results obtained provide information on the role played by subexcitation-energy electrons and dissociative electron attachment in the radiosensitization of DNA by Pt-drugs, which is an important step to unravel the mechanisms of radiosensitization of these agents in chemo-radiation cancer therapy. (authors)

  13. Low-energy-electron interactions with DNA: approaching cellular conditions with atmospheric experiments

    Science.gov (United States)

    Alizadeh, Elahe; Sanche, Léon

    2014-04-01

    A novel technique has been developed to investigate low energy electron (LEE)-DNA interactions in the presence of small biomolecules (e.g., N2, O2, H2O) found near DNA in the cell nucleus, in order to simulate cellular conditions. In this technique, LEEs are emitted from a metallic surface exposed by soft X-rays and interact with DNA thin films at standard ambient temperature and pressure (SATP). Whereas atmospheric N2 had little effect on the yields of LEE-induced single and double strand breaks, both O2 and H2O considerably modified and increased such damage. The highest yields were obtained when DNA is embedded in a combined O2 and H2O atmosphere. In this case, the amount of additional double strand breaks was supper-additive. The effect of modifying the chemical and physical stability of DNA by platinum-based chemotherapeutic agents (Pt-drugs) including cisplatin, carboplatin and oxaliplatin was also investigated with this technique. The results obtained provide information on the role played by subexcitation-energy electrons and dissociative electron attachment in the radiosensitization of DNA by Pt-drugs, which is an important step to unravel the mechanisms of radiosensitisation of these agents in chemoradiation cancer therapy.

  14. Heat storage in forest biomass significantly improves energy balance closure particularly during stable conditions

    Science.gov (United States)

    Lindroth, A.; Mölder, M.; Lagergren, F.

    2009-08-01

    Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and -35 W m-2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m-2 and the minimum was -35 W m-2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation nearly perfectly. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. -0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy

  15. Energy and exergy analysis of a geothermal heat pump air conditioning system

    International Nuclear Information System (INIS)

    Baccoli, Roberto; Mastino, Costantino; Rodriguez, Giuseppe

    2015-01-01

    This paper considers the energy analysis of a heat pump system coupled to the ground by means of vertical exchangers, to verify which thermodynamic boundary conditions, in terms of thermal conductivity and diffusivity of the ground and the grout, make it competitive in comparison with other technologies harnessing atmospheric air as the heat source. The comparison is based on the maximum theoretical efficiency available in correspondence to the temperature effectively assumed by the thermal energy reservoirs in contact with the evaporator and the condenser during the operating conditions. The comparison of the two sources/sinks of heat, i.e. the ground and atmospheric air, represents the comparison between the time trend of the exergy of the two reservoirs required by an ideal GSHP and ASHP respectively. A fully transient heat transfer model able to handle on a time scale of a year or more and with a refinement of less than an hour is considered, since short term variations have significant effects on the overall performance of GSHP. In this paper the borehole heat transfer problem in the Laplace domain is solved for any trend and duration of thermal loads, taking into account an existing analytical approximation model of the full solution proposed by Lamarche and Beauchamp. A numerical inversion using the Inverse Discrete Fourier Transform is then applied to obtain the time domain solution. The method combines the flexibility and accuracy of the analytical model with the superior efficiency of the computational time offered by the numerical inversion if compared with that of methods based on the convolution scheme. - Highlights: • The energy and exergy analysis of a GSHP versus a ASHP system is considered. • The model works on a time scale of a year, with a refinement of less than an hour. • Flexibility and efficiency are combined by an analytical model and numerical inversion. • For which order of λ and α the GSHP is not competitive respect to ASHP is

  16. Quantifying conditional risks for water and energy systems using climate information

    Science.gov (United States)

    Lall, U.

    2016-12-01

    There has been a growing recognition of the multi-scale spatio-temporal organization of climate dynamics, and its implications for predictable, structured risk exposure to populations and infrastructure systems. At the most base level is an understanding that there are some identifiable climate modes, such as ENSO, that are associated with such outcomes. This has led to the emergence of a small cottage industry of analysts who relate different "climate indices" to specific regional outcomes. Such efforts and the associated media interest in these simplified "stories" have led to an increasing appreciation of the phenomenon, and some formal and informal efforts at decision making using such information. However, as was demonstrated through the 2014-16 El Nino forecasting season, many climate scientists over-emphasized the potential risks, while others cautioned the media as to the caveats and uncertainties associated with assuming that the forecasts of ENSO and the expected teleconnections may pan out. At least in certain sectors and regions, significant efforts or expectations as to outcomes were put in place, and some were beneficial, while others failed to manifest. Climate informed predictions for water and energy systems can be thought of as efforts to infer conditional distributions of specific outcomes given information on climate state. Invariably, the climate state may be presented as a very high dimensional spatial set of variables, with limited temporal sampling, while the water and energy attributes may be regional and constitute a much smaller dimension. One may, of course, be interested in the fact that the same climate state may lead to synchronous positive and negative effects across many locations, as may be expected under mid-latitude stationary and transient wave interaction. In this talk, I will provide examples of a few modern statistical and machine learning tools that allow a decomposition of the high dimensional climate state and its relation

  17. Structural analysis of porous rock reservoirs subjected to conditions of compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Friley, J.R.

    1980-01-01

    Investigations are described which were performed to assess the structural behavior of porous rock compressed air energy storage (CAES) reservoirs subjected to loading conditions of temperature and pressure felt to be typical of such an operation. Analyses performed addressed not only the nominal or mean reservoir response but also the cyclic response due to charge/discharge operation. The analyses were carried out by assuming various geometrical and material related parameters of a generic site. The objective of this study was to determine the gross response of a generic porous reservoir. The site geometry for this study assumed a cylindrical model 122 m in dia and 57 m high including thicknesses for the cap, porous, and base rock formations. The central portion of the porous zone was assumed to be at a depth of 518 m and at an initial temperature of 20/sup 0/C. Cyclic loading conditions of compressed air consisted of pressure values in the range of 4.5 to 5.2 MPa and temperature values between 143 and 204/sup 0/C.Various modes of structural behavior were studied. These response modes were analyzed using loading conditions of temperature and pressure (in the porous zone) corresponding to various operational states during the first year of simulated site operation. The results of the structural analyses performed indicate that the most severely stressed region will likely be in the wellbore vicinity and hence highly dependent on the length of and placement technique utilized in the well production length. Analyses to address this specific areas are currently being pursued.

  18. THE USE OF AIR LAYERS IN BUILDING ENVELOPES FOR ENERGY SAVING DURING AIR CONDITIONING

    Directory of Open Access Journals (Sweden)

    S. N. Osipov

    2017-01-01

    Full Text Available Since there are no large natural energy resources in Belarus, energy savings ought to be a point of the special attention. With this regard it is important to develop modern ways of savings during the process of air conditioning inside new buildings with an air layer in the enclosure, especially in translucent ones. The system of ventilation of air layers in the enclosure of a building has been introduced in which air movement is caused by the gravitational and aerodynamic forces. It makes it possible to arrange further ventilation – a natural, forced or a hybrid one. With the purpose of increasing and streamlining natural draught the partitions are used separating the different parts of air layers. For natural ventilation with the use of gravitational forces the holes in the upper and lower parts of the partitions between adjacent air layers are applied. Natural ventilation in the holes of the partitions is regulated by movable shutters, blinds or other adjusting devices. For combined or forced air exchange between adjacent zones of air layers fans are used pumping air from the air layer zones with a higher temperature to zones of air layers with lower temperature and vice versa. When air exchange is forced, in order to intensify the infiltration of air into zones of air layers jets are laid on a hard surface. In order to cool a multi-layered enclosure of a building, where the movement of air between the air layers (that have been formed by internal partitions is being fulfilled by a natural, forced or combined mode, a part of the air or the total air processed inside the building (i.e. conditioned or non-conditioned air cooler as compared with the outside one is being sent to these strata. Combined or forced flow of the air processed inside the building into the air layers is done through the ducts associated with the output channels of the air conditioners. The internal partitions are equipped with the air valve hole.

  19. Cooling energy efficiency and classroom air environment of a school building operated by the heat recovery air conditioning unit

    International Nuclear Information System (INIS)

    Wang, Yang; Zhao, Fu-Yun; Kuckelkorn, Jens; Liu, Di; Liu, Li-Qun; Pan, Xiao-Chuan

    2014-01-01

    The recently-built school buildings have adopted novel heat recovery ventilator and air conditioning system. Heat recovery efficiency of the heat recovery facility and energy conservation ratio of the air conditioning unit were analytically modeled, taking the ventilation networks into account. Following that, school classroom displacement ventilation and its thermal stratification and indoor air quality indicated by the CO 2 concentration have been numerically modeled concerning the effects of delivering ventilation flow rate and supplying air temperature. Numerical results indicate that the promotion of mechanical ventilation rate can simultaneously boost the dilution of indoor air pollutants and the non-uniformity of indoor thermal and pollutant distributions. Subsequent energy performance analysis demonstrates that classroom energy demands for ventilation and cooling could be reduced with the promotion of heat recovery efficiency of the ventilation facility, and the energy conservation ratio of the air conditioning unit decreases with the increasing temperatures of supplying air. Fitting correlations of heat recovery ventilation and cooling energy conservation have been presented. - Highlights: • Low energy school buildings and classroom environment. • Heat recovery facility operating with an air conditioning unit. • Displacement ventilation influenced by the heat recovery efficiency. • Energy conservation of cooling and ventilation through heat recovery. • Enhancement of classroom environment with reduction of school building energy

  20. Modeling global residential sector energy demand for heating and air conditioning in the context of climate change

    International Nuclear Information System (INIS)

    Isaac, Morna; Vuuren, Detlef P. van

    2009-01-01

    In this article, we assess the potential development of energy use for future residential heating and air conditioning in the context of climate change. In a reference scenario, global energy demand for heating is projected to increase until 2030 and then stabilize. In contrast, energy demand for air conditioning is projected to increase rapidly over the whole 2000-2100 period, mostly driven by income growth. The associated CO 2 emissions for both heating and cooling increase from 0.8 Gt C in 2000 to 2.2 Gt C in 2100, i.e. about 12% of total CO 2 emissions from energy use (the strongest increase occurs in Asia). The net effect of climate change on global energy use and emissions is relatively small as decreases in heating are compensated for by increases in cooling. However, impacts on heating and cooling individually are considerable in this scenario, with heating energy demand decreased by 34% worldwide by 2100 as a result of climate change, and air-conditioning energy demand increased by 72%. At the regional scale considerable impacts can be seen, particularly in South Asia, where energy demand for residential air conditioning could increase by around 50% due to climate change, compared with the situation without climate change

  1. Decoupling dehumidification and cooling for energy saving and desirable space air conditions in hot and humid Hong Kong

    International Nuclear Information System (INIS)

    Lee, W.L.; Chen Hua; Leung, Y.C.; Zhang, Y.

    2012-01-01

    Highlights: ► The combined use of dedicated ventilation and dry cooling (DCDV) system was investigated. ► Investigations were based actual equipment performance data and realistic building and system characteristics. ► DCDV system could save 54% of the annual energy use for air-conditioning. ► DCDV system could better achieve the desired space air conditions. ► DCDV system could decouple dehumidification and cooling. - Abstract: The combined use of dedicated outdoor air ventilation (DV) and dry cooling (DC) air-conditioning system to decouple sensible and latent cooling for desirable space air conditions, better indoor air quality, and energy efficiency is proposed for hot and humid climates like Hong Kong. In this study, the performance and energy saving potential of DCDV system in comparison to conventional systems (constant air volume (CAV) system with and without reheat) for air conditioning of a typical office building in Hong Kong are evaluated. Through hour-by-hour simulations, using actual equipment performance data and realistic building and system characteristics, the cooling load profile, resultant indoor air conditions, condensation at the DC coil, and energy consumptions are calculated and analyzed. The results indicate that with the use of DCDV system, the desirable indoor conditions could be achieved and the annual energy use could be reduced by 54% over CAV system with reheat. The condensate-free characteristic at the DC coil to reduce risk of catching disease could also be realized.

  2. China could satisfied her energy demand by her domestic resource of renewable and hydrogen energy and with her favorite condition

    International Nuclear Information System (INIS)

    Bao De You

    2006-01-01

    Paper described recent situation and the reason of oils consumed increasing rapidly and the activity for searching oil around the world wide and proposed some suggestion for rapid development and commercialization of hydrogen energy system in China with her domestic resources. China could satisfy the energy demand with her domestic resources of renewable energies and depending on her domestic scientific and technology and personal resources etc. It could Clean up the misunderstanding of other country and worried about the oil price increasing. (author)

  3. A note on the conditional density estimate in single functional index model

    OpenAIRE

    2010-01-01

    Abstract In this paper, we consider estimation of the conditional density of a scalar response variable Y given a Hilbertian random variable X when the observations are linked with a single-index structure. We establish the pointwise and the uniform almost complete convergence (with the rate) of the kernel estimate of this model. As an application, we show how our result can be applied in the prediction problem via the conditional mode estimate. Finally, the estimation of the funct...

  4. Evaluation of the Energy and Comfort Performance of a Plus-Energy House under Scandinavian Summer Conditions

    DEFF Research Database (Denmark)

    Pean, Thibault Quentin; Gennari, Luca; Kazanci, Ongun Berk

    2016-01-01

    The thermal indoor environment and the energy performance of a plus-energy house are evaluated in the present study. The study case is EMBRACE, a two-storey dwelling of 59 m2 designed to host a single family. The building includes a semi-outdoor space covered by a glazed envelope, where the therm...

  5. A Correction of Random Incidence Absorption Coefficients for the Angular Distribution of Acoustic Energy under Measurement Conditions

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho

    2009-01-01

    Most acoustic measurements are based on an assumption of ideal conditions. One such ideal condition is a diffuse and reverberant field. In practice, a perfectly diffuse sound field cannot be achieved in a reverberation chamber. Uneven incident energy density under measurement conditions can cause...... discrepancies between the measured value and the theoretical random incidence absorption coefficient. Therefore the angular distribution of the incident acoustic energy onto an absorber sample should be taken into account. The angular distribution of the incident energy density was simulated using the beam...... tracing method for various room shapes and source positions. The averaged angular distribution is found to be similar to a Gaussian distribution. As a result, an angle-weighted absorption coefficient was proposed by considering the angular energy distribution to improve the agreement between...

  6. Energy metrics of photovoltaic/thermal and earth air heat exchanger integrated greenhouse for different climatic conditions of India

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, Sujata; Tiwari, G.N. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2010-10-15

    In this paper, a study is carried out to evaluate the annual thermal and exergy performance of a photovoltaic/thermal (PV/T) and earth air heat exchanger (EAHE) system, integrated with a greenhouse, located at IIT Delhi, India, for different climatic conditions of Srinagar, Mumbai, Jodhpur, New Delhi and Bangalore. A comparison is made of various energy metrics, such as energy payback time (EPBT), electricity production factor (EPF) and life cycle conversion efficiency (LCCE) of the system by considering four weather conditions (a-d type) for five climatic zones. The embodied energy and annual energy outputs have been used for evaluation of the energy metrics. The annual overall thermal energy, annual electrical energy savings and annual exergy was found to be best for the climatic condition of Jodhpur at 29,156.8 kWh, 1185 kWh and 1366.4 kWh, respectively when compared with other weather stations covered in the study, due to higher solar intensity I and sunshine hours, and is lowest for Srinagar station. The results also showed that energy payback time for Jodhpur station is lowest at 16.7 years and highest for Srinagar station at 21.6 years. Electricity production factor (EPF) is highest for Jodhpur, i.e. 2.04 and Life cycle conversion efficiency (LCCE) is highest for Srinagar station. It is also observed that LCCE increases with increase in life cycle. (author)

  7. The Temperature Condition of the Plate with Temperature-Dependent Thermal Conductivity and Energy Release

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    Full Text Available The temperature state of a solid body, in addition to the conditions of its heat exchange with the environment, can greatly depend on the heat release (or heat absorption processes within the body volume. Among the possible causes of these processes should be noted such as a power release in the fuel elements of nuclear reactors, exothermic or endothermic chemical reactions in the solid body material, which respectively involve heat release or absorbtion, heat transfer of a part of the electric power in the current-carrying conductors (so-called Joule’s heat or the energy radiation penetrating into the body of a semitransparent material, etc. The volume power release characterizes an intensity of these processes.The extensive list of references to the theory of heat conductivity of solids offers solutions to problems to determine a stationary (steady over time and non-stationary temperature state of the solids (as a rule, of the canonical form, which act as the sources of volume power release. Thus, in general case, a possibility for changing power release according to the body volume and in solving the nonstationary problems also a possible dependence of this value on the time are taken into consideration.However, in real conditions the volume power release often also depends on the local temperature, and such dependence can be nonlinear. For example, with chemical reactions the intensity of heat release or absorption is in proportion to their rate, which, in turn, is sensitive to the temperature value, and a dependence on the temperature is exponential. A further factor that in such cases makes the analysis of the solid temperature state complicated, is dependence on the temperature and the thermal conductivity of this body material, especially when temperature distribution therein  is significantly non-uniform. Taking into account the influence of these factors requires the mathematical modeling methods, which allow us to build an adequate

  8. Modular Hamiltonians for deformed half-spaces and the averaged null energy condition

    Science.gov (United States)

    Faulkner, Thomas; Leigh, Robert G.; Parrikar, Onkar; Wang, Huajia

    2016-09-01

    We study modular Hamiltonians corresponding to the vacuum state for deformed half-spaces in relativistic quantum field theories on {{R}}^{1,d-1} . We show that in addition to the usual boost generator, there is a contribution to the modular Hamiltonian at first order in the shape deformation, proportional to the integral of the null components of the stress tensor along the Rindler horizon. We use this fact along with monotonicity of relative entropy to prove the averaged null energy condition in Minkowski space-time. This subsequently gives a new proof of the Hofman-Maldacena bounds on the parameters appearing in CFT three-point functions. Our main technical advance involves adapting newly developed perturbative methods for calculating entanglement entropy to the problem at hand. These methods were recently used to prove certain results on the shape dependence of entanglement in CFTs and here we generalize these results to excited states and real time dynamics. We also discuss the AdS/CFT counterpart of this result, making connection with the recently proposed gravitational dual for modular Hamiltonians in holographic theories.

  9. Heat exchange studies on coconut oil cells as thermal energy storage for room thermal conditioning

    Science.gov (United States)

    Sutjahja, I. M.; Putri, Widya A.; Fahmi, Z.; Wonorahardjo, S.; Kurnia, D.

    2017-07-01

    As reported by many thermal environment experts, room air conditioning might be controlled by thermal mass system. In this paper we discuss the performance of coconut oil cells as room thermal energy storage. The heat exchange mechanism of coconut oil (CO) which is one of potential organic Phase Change Material (PCM) is studied based on the results of temperature measurements in the perimeter and core parts of cells. We found that the heat exchange performance, i.e. heat absorption and heat release processes of CO cells are dominated by heat conduction in the sensible solid from the higher temperature perimeter part to the lower temperature core part and heat convection during the solid-liquid phase transition and sensible liquid phase. The capability of heat absorption as measured by the reduction of air temperature is not influenced by CO cell size. Besides that, the application of CO as the thermal mass has to be accompanied by air circulation to get the cool sensation of the room’s occupants.

  10. Traversable wormholes satisfying the weak energy condition in third-order Lovelock gravity

    Science.gov (United States)

    Zangeneh, Mahdi Kord; Lobo, Francisco S. N.; Dehghani, Mohammad Hossein

    2015-12-01

    In this paper, we consider third-order Lovelock gravity with a cosmological constant term in an n -dimensional spacetime M4×Kn -4, where Kn -4 is a constant curvature space. We decompose the equations of motion to four and higher dimensional ones and find wormhole solutions by considering a vacuum Kn -4 space. Applying the latter constraint, we determine the second- and third-order Lovelock coefficients and the cosmological constant in terms of specific parameters of the model, such as the size of the extra dimensions. Using the obtained Lovelock coefficients and Λ , we obtain the four-dimensional matter distribution threading the wormhole. Furthermore, by considering the zero tidal force case and a specific equation of state, given by ρ =(γ p -τ )/[ω (1 +γ )], we find the exact solution for the shape function which represents both asymptotically flat and nonflat wormhole solutions. We show explicitly that these wormhole solutions in addition to traversibility satisfy the energy conditions for suitable choices of parameters and that the existence of a limited spherically symmetric traversable wormhole with normal matter in a four-dimensional spacetime implies a negative effective cosmological constant.

  11. Online optimal control of variable refrigerant flow and variable air volume combined air conditioning system for energy saving

    International Nuclear Information System (INIS)

    Zhu, Yonghua; Jin, Xinqiao; Du, Zhimin; Fang, Xing

    2015-01-01

    The variable refrigerant flow (VRF) and variable air volume (VAV) combined air conditioning system can solve the problem of the VRF system in outdoor air ventilation while taking advantage of its high part load energy efficiency. Energy performance of the combined air conditioning system can also be optimized by joint control of both the VRF and the VAV parts. A model-based online optimal control strategy for the combined air conditioning system is presented. Simplified adaptive models of major components of the combined air conditioning system are firstly developed for predicting system performances. And a cost function in terms of energy consumption and thermal comfort is constructed. Genetic algorithm is used to search for the optimal control sets. The optimal control strategy is tested and evaluated through two case studies based on the simulation platform. Results show that the optimal strategy can effectively reduce energy consumption of the combined air conditioning system while maintaining acceptable thermal comfort. - Highlights: • A VRF and VAV combined system is proposed. • A model-based online optimal control strategy is proposed for the combined system. • The strategy can reduce energy consumption without sacrificing thermal comfort. • Novel simplified adaptive models are firstly developed for the VRF system

  12. The daily hour forecasting of the electrical energy production from renewable energy sources – a required condition for the operation of the new energy market model

    International Nuclear Information System (INIS)

    Kalpachka, Gergana; Kalpachki, Georgi

    2011-01-01

    The report presented the new energy market model in Bulgaria and the main attention is directed to a daily hour forecasting of the electrical energy production from renewable energy sources. The need of development of a methodology and the development of the most precise methods for predicting is reviewed and some of the used methods at the moment are presented. An analysis of the problems related to the daily hour forecasting is done using data from the producers of electrical energy from renewable energy sources in the territory of western Bulgaria. Keywords: Renewable energy sources, daily hour forecasting, electrical energy

  13. Offshore Resource Assessment and Design Conditions: A Data Requirements and Gaps Analysis for Offshore Renewable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Dennis [National Renewable Energy Lab. (NREL), Golden, CO (United States); Frame, Caitlin [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Gill, Carrie [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Hanson, Howard [Florida Atlantic Univ., Boca Raton, FL (United States); Moriarty, Patrick [National Renewable Energy Lab. (NREL), Golden, CO (United States); Powell, Mark [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Shaw, William J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wilczak, Jim [National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States); Wynne, Jason [Energetics, Columbia, MD (United States)

    2012-03-01

    The offshore renewable energy industry requires accurate meteorological and oceanographic (“metocean”) data for evaluating the energy potential, economic viability, and engineering requirements of offshore renewable energy projects. It is generally recognized that currently available metocean data, instrumentation, and models are not adequate to meet all of the stakeholder needs on a national scale. Conducting wind and wave resource assessments and establishing load design conditions requires both interagency collaboration as well as valuable input from experts in industry and academia. Under the Department of Energy and Department of Interior Memorandum of Understanding, the Resource Assessment and Design Condition initiative supports collaborative national efforts by adding to core atmospheric and marine science knowledge relevant to offshore energy development. Such efforts include a more thorough understanding and data collection of key metocean phenomena such as wind velocity and shear; low-level jets; ocean, tidal, and current velocities; wave characteristics; geotechnical data relating to surface and subsurface characteristics; seasonal and diurnal variations; and the interaction among these conditions. Figure 1 presents a graphical representation of some metocean phenomena that can impact offshore energy systems. This document outlines the metocean observations currently available; those that are not available; and those that require additional temporal-spatial coverage, resolution, or processing for offshore energy in an effort to gather agreed-upon, needed observations.

  14. Simulation of the impact of financial incentives on solar energy utilization for space conditioning and water heating: 1985

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, H C

    1979-01-01

    Financial incentives designed to accelerate the use of solar energy for heating, cooling, and water heating of buildings have been proposed by both state and federal legislative bodies in the U.S.A. Among the most frequently mentioned incentives are sales and property tax exemptions, tax deductions and credits, rapid amortization provisions, and interest rate subsidies. At the present time there is little available information regarding the ability of such incentives to advance the rate of solar energy utilization. This paper describes the derivation and use of a computer simulation model designed to estimate solar energy use for space conditioning and water heating for given economic, climatic, and technological conditions. When applied to data from the Denver, Colorado metropolitan area, the simulation model predicts that sales tax exemptions would have little impact over the next decade, interest rate subsidies could more than double solar energy use, and the other proposed incentives would have an intermediate impact.

  15. A low-energy building under arctic conditions – a case study

    DEFF Research Database (Denmark)

    Norling, Casper Roland; Rode, Carsten; Svendsen, Svend

    2006-01-01

    Greenland is a relatively small community with limited natural resources, which results in the necessity to import all supplies, including a big share of the energy. Because of this, it is important to decrease the energy consumption. This can be done by developing new construction technology wit...... in the new Greenlandic building regulations....... with larger focus on energy efficiency. Therefore a low-energy house, located in Sisimiut, has been constructed. The low-energy house will be a forerunner for the development of new building element designs and technologies in Greenland. In the forthcoming years, the house will also be a base for scientific...... projects which will evaluate the design of the low-energy house including an assessment of the effect of the highly insulated building envelope, advanced windows and a ventilation system with heat recovery, all of which cuts the energy consumption of the building to half of what will be the requirement...

  16. Renewable energy to develop adaptation strategies to the climate change conditions

    Science.gov (United States)

    Servadio, Pieranna; Bergonzoli, Simone

    2013-04-01

    between the corn rows. During the irrigation tests for the autoclave pressure values already mentioned, we obtained an 80 l min-1 flow rate value with a 28 m head value measured by pressure gauge upstream from the electric pump. In these conditions and on sunny days a 26 m3 water body was obtained. From the agronomic point of view, the crop developed more than usual, did not undergo parasite attack nor lodging or cutting off of the steams during the biological cycle, and the development of weeds was limited. The grain production amounted to 10.5 t ha-1, 12.4 % higher with respect to the rain-irrigated parcels. Crop yield results showed better performance of the drip irrigation plant with respect to the sprinkler system. The photovoltaic system met design expectations and showed good reliability during the years of testing. The long-term tests showed that the photovoltaic system is capable of supplying a farm. The problem linked with combustion of fossil fuel will improve this system of energy supply to agricultural farms located in areas not reached by the power network both in Europe and in the sub Saharan countries where many plans are developing in last year pursuing also the scope of a drastic reduction of GHG fluxes. Acknowledgements This work was carried out under the auspices of the special project "Sceneries of adaptation of the Italian agriculture to the climatic changes" (AGROSCENARI) of the Agricultural Research Council, and Italian Ministry of the Agricultural and Forestry Politics.

  17. Effect of Ducted HPWH on Space-Conditioning and Water Heating Energy Use -- Central Florida Lab Home

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Martin, Eric [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Parker, Danny [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States)

    2016-11-01

    The purpose of this research is to investigate the impact of ducted heat pump water heaters (HPWHs) on space conditioning and water heating energy use in residential applications. Two identical HPWHs, each of 60 gallon capacity were tested side by side at the Flexible Residential Test facility (FRTF) laboratories of the Florida Solar Energy Center (FSEC) campus in Cocoa, Florida. The water heating experiments were run in each test house from July 2014 until February 2015.

  18. Effect of Ducted HPWH on Space-Conditioning and Water Heating Energy Use -- Central Florida Lab Home

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States); Martin, Eric [Florida Solar Energy Center, Cocoa, FL (United States); Parker, Danny [Florida Solar Energy Center, Cocoa, FL (United States)

    2016-11-01

    The purpose of this research is to investigate the impact of ducted heat pump water heaters (HPWH's) on space conditioning and water heating energy use in residential applications. Two identical HPWH's, each of 60 gallon capacity were tested side by side at the Flexible Residential Test facility (FRTF) laboratories of the Florida Solar Energy Center (FSEC) campus in Cocoa, Florida. The water heating experiments were run in each test house from July 2014 until February 2015.

  19. Energy Savings and Economics of Advanced Control Strategies for Packaged Air-Conditioning Units with Gas Heat

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.

    2011-12-31

    Pacific Northwest National Laboratory (PNNL) with funding from the U.S. Department of Energy's Building Technologies Program (BTP) evaluated a number of control strategies that can be implemented in a controller, to improve the operational efficiency of the packaged air conditioning units. The two primary objectives of this research project are: (1) determine the magnitude of energy savings achievable by retrofitting existing packaged air conditioning units with advanced control strategies not ordinarily used for packaged units and (2) estimating what the installed cost of a replacement control with the desired features should be in various regions of the U.S. This document reports results of the study.

  20. Energy law. The legal boundary conditions of power supply. 2. rev. ed.

    International Nuclear Information System (INIS)

    Stuhlmacher, Gerd; Stappert, Holger; Jansen, Guido

    2015-01-01

    Now appearing in its second edition, this book presents a comprehensive overview of the legal framework governing the energy sector. It provides readily understandable coverage, across the relevant subfields of law, of the legal regulations applicable to any manner of activity in the energy sector along with a wealth of practical advice on the interpretation and application of legal provisions. The content has been thoroughly revised, updated to reflect the current status of legislation and supplemented with numerous chapters. The 2014 amendment of the Renewable Energy Law (EEG) and its practical impact have also been taken into account. The following topics are covered amongst others: unbundling of network operation; connection and access to networks and metering; network charges and incentive regulation; easement contracts; energy supply and basic services; energy and electricity taxes; cartel law, law on operating aids, procurement law; energy trade OTC and at exchanges; energy trade surveillance law; fuel production and fracking; conventional and nuclear power production; renewable energy production (including offshore production); energy storage and power-to-gas; transmission line construction; climate protection (including the 2014 EEG, emission trade and the Law on the Promotion of Renewable Energy in the Heat Sector); cogeneration law, district heating and contracting; and investment protection.

  1. Conditions for a 100% Renewable Energy Supply System in Japan and South Korea

    DEFF Research Database (Denmark)

    Sørensen, Bent Erik

    2017-01-01

    renewable energy have proposed the use of photovoltaic power as the main source of electricity supply, in combination with diurnal battery storage and supplemented by other renewable sources such as wind, hydro, and geothermal power. Here, an alternative approach is explored, with wind and derived hydrogen......In the wake of the Fukushima nuclear accident, alternative energy paths have been discussed for Japan, but except for a few studies the assumption is usually made that Japan is too densely populated to be suited for a near-100% sustainable, indigenous energy provision. The studies emphasizing...... production as the main energy source, but still using solar energy, biofuels, and hydropower in a resilient combination allowing full satisfaction of demands in all sectors of the economy, i.e., for dedicated electricity, transportation energy as well as heat for processes and comfort. Furthermore...

  2. Leveling off the energy demand. Air conditioning by town gas NEXT STAGE. Energy juyo no heijunka wo motomete. Gas reibo NEXT STAGE

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, K. (Keio Univ., Tokyo (Japan). Faculty of Science and Technology)

    1994-07-01

    Utilizing various types of energy with combining them rationally is now drawing attention. One of these types of energy is the town gas. The air conditioning by town gas draws a special attention. The town gas is characterized by environmental conservation, energy saving, and comfortability. The town gas does not contain sulfur compounds which cause the acid rain. The town gas produces the least amount of carbon dioxide among all the fossil fuel. The air conditioning by the town gas is getting popular. Examples are Tokyo Dome in Tokyo, Pavilion Plaza, a new shopping spot in Fukuoka, Umeda Sky Building in Osaka, Dai-ich Apparel Center in Tokyo, Ohno Memorial Hospital in Osaka, Nagoya Municipal Integrated Stadium in Nagoya, Meguro-Gajoen in Tokyo, and New Yomiuri-Shimbun Building in Sapporo. 41 figs.

  3. Structural studies of disordered materials using high-energy x-ray diffraction from ambient to extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kohara, Shinji [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Itou, Masayoshi [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Suzuya, Kentaro [Japan Atomic Energy Agency (J-PARC/JAEA), Tokai, Naka, Ibaraki 319-1195 (Japan); Inamura, Yasuhiro [Japan Atomic Energy Agency (J-PARC/JAEA), Tokai, Naka, Ibaraki 319-1195 (Japan); Sakurai, Yoshiharu [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Ohishi, Yasuo [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Takata, Masaki [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

    2007-12-19

    High-energy x-rays from a synchrotron radiation source allow us to obtain high-quality diffraction data for disordered materials from ambient to extreme conditions, which is necessary for revealing the detailed structures of glass, liquid and amorphous materials. We introduced high-energy x-ray diffraction beamlines and a dedicated diffractometer for glass, liquid and amorphous materials at SPring-8 and report the recent developments of ancillary equipment. Furthermore, the structures of liquid and amorphous materials determined from the high-energy x-ray diffraction data obtained at SPring-8 are discussed.

  4. Occupant performance and building energy consumption with different philosophies of determining acceptable thermal conditions

    DEFF Research Database (Denmark)

    Toftum, Jørn; Andersen, Rune Vinther; Jensen, Kasper Lynge

    2009-01-01

    Based on building energy and indoor environment simulations, this study uses a recently developed method relying on Bayesian Network theory to estimate and compare the consequences for occupant performance and energy consumption of applying temperature criteria set according to the adaptive model...... configurations, especially in the tropical climate, the estimated performance differed only modestly between configurations. However, energy consumption was always lower in buildings without mechanical cooling, particularly so in the tropical climate. The findings indicate that determining acceptable indoor...... thermal environments with the adaptive comfort model may result in significant energy savings and at the same time will not have large consequences for the mental performance of occupants....

  5. Integration of Low Energy Technologies for Optimal Building and Space Conditioning Design

    Energy Technology Data Exchange (ETDEWEB)

    D.E. Fisher

    2006-01-07

    EnergyPlus is the DOE's newest building energy simulation engine. It was developed specifically to support the design of low energy building systems. This project focused on developing new low energy building simulation models for EnergyPlus, verifying and validating new and existing EnergyPlus models and transferring the new technology to the private sector. The project focused primarily on geothermal and radiant technologies, which are related by the fact that both are based on hydronic system design. As a result of this project eight peer reviewed journal and conference papers were added to the archival literature and five technical reports were published as M.S. theses and are available in the archival literature. In addition, several reports, including a trombe wall validation report were written for web publication. Thirteen new or significantly enhanced modules were added to the EnergyPlus source code and forty-two new or significantly enhanced sections were added to the EnergyPlus documentation as a result of this work. A low energy design guide was also developed as a pedagogical tool and is available for web publication. Finally several tools including a hybrid ground source heat pump optimization program and a geothermal heat pump parameter estimation tool were developed for research and design and are available for web publication.

  6. The Legal Conditions for Water Utilities Eco-Innovation as Energy Smart Water Utilities

    DEFF Research Database (Denmark)

    Basse, Ellen Margrethe

    2013-01-01

    Welfare and green growth rest havely on an appropriate supply of safe water, the provision of adequate sewage, and on energy services. These services are interdependent, as water is an integral part of electric-power generation. Energy is also an integrated part of water services, as satisfying w...

  7. Sun as an inexhaustible source of energy. Applications for space heating - cooling and air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Zink, H [Solarheiztechnik G.m.b.H. und Co. K.G., Unterensingen (Germany, F.R.)

    1977-09-01

    Possible focal points for the utilization of solar energy in the field of domestic buildings and in the communal sector with hot water preparation for sport centres, swimming baths, hospitals, industry, and service are discussed. A diagram of a hot water preparation plant with solar collectors and stores is included, and preconditions for cooling with solar energy are discussed.

  8. Impact of changing conditions in the oil market on energy policies in the ESCWA region

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The present study has been prepared in the implementation of the ESCWA work programme and priorities for 1988/1989. It is aimed at examining energy issues of major concern to the region particularly the changes in the oil market, fluctuations of oil prices and their impact on energy plans and policies. The study is also intended to serve as a background document to the Meeting organized to discuss salient energy issues arising from recent developments in the oil market. It has therefore been designed to deal with downstream and upstream activities, adjustments to contractual terms, and market and national energy policies following the violent fluctuations of oil prices. Some futuristic views on the oil market are also presented and the study includes an examination of national and regional entities involved in energy issues and development of oil resources in the ESCWA region. (Author)

  9. The static friction response of non-glabrous skin as a function of surface energy and environmental conditions

    NARCIS (Netherlands)

    Klaassen, Michel; de Vries, Erik G.; Masen, Marc Arthur

    2017-01-01

    The (local) environmental conditions have a significant effect on the interaction between skin and products. Plasticisation of the stratum corneum occurs at high humidity, causing this layer to soften and change its surface free energy. In this work we study the effects of the micro-climate on the

  10. An estimate of conditioned waste arisings to the years 2000 and 2010 for the Department of Energy power generation scenarios

    International Nuclear Information System (INIS)

    Fairclough, M.P.; Moore, D.C.; Tymons, B.J.

    1984-09-01

    An estimate of conditioned waste arisings to the years 2000 and 2010 has been made using evidence presented at the Sizewell 'B' public enquiry. The method of calculation has been based on the rate of arisings per GWe year and the power programmes of the Department of Energy. (author)

  11. The conditions for total reflection of low-energy atoms from crystal surfaces

    International Nuclear Information System (INIS)

    Hou, M.; Robinson, M.T.

    1978-01-01

    The critical angles for the total reflection of low-energy particles from Cu rows and (001) planes have been investigated, using the binary collision approximation computer simulation code MARLOWE Breakthrough angles were evaluated for H, N, Ne, Ar, Cu, Xe, and Au in the energy range from 0.1 to 7.5 keV. In both the axial and the planar cases, recoiling of the target atoms lowers the energy barrier which the target surface presents to the heavy projectiles. Consequently, the breakthrough angles are reduced for heavy projectiles below the values expected either from observations on light projectiles or from analytical channeling theory. (orig.) [de

  12. International Energy Agency Building Energy Simulation Test and Diagnostic Method for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST); Volume 1: Cases E100-E200

    Energy Technology Data Exchange (ETDEWEB)

    Neymark, J.; Judkoff, R.

    2002-01-01

    This report describes the Building Energy Simulation Test for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST) project conducted by the Tool Evaluation and Improvement International Energy Agency (IEA) Experts Group. The group was composed of experts from the Solar Heating and Cooling (SHC) Programme, Task 22, Subtask A. The current test cases, E100-E200, represent the beginning of work on mechanical equipment test cases; additional cases that would expand the current test suite have been proposed for future development.

  13. Prediction model of energy consumption in Jiangsu Province based on constraint condition of carbon emission

    Science.gov (United States)

    Chang, Z. G.; Xue, T. T.; Chen, Y. J.; Chao, X. H.

    2017-11-01

    In order to achieve the targets for energy conservation and economic development goals in Jiangsu Province under the constraint of carbon emission, this paper uses the gray GM (1,1) model to predict and optimize the consumption structure of major energy sources (coal, oil, natural gas, etc.) in Jiangsu province in the "13th Five-Year" period and the next seven years. The predictions meet the requirement of reducing carbon dioxide emissions per unit GDP of China by 50%. The results show that the proposed approach and model is effective. Finally, we put forward opinions and suggestions on the way of energy-saving and emission-reduction, the adjustment of energy structure and the policy of coal consumption in Jiangsu Province.

  14. Nuclear energy in Ukraine in the conditions of political-economical crisis

    International Nuclear Information System (INIS)

    Kuharchuk, N. P.; Kosharnaya, O. P.; Siora, A. A.; Reshetitskij, S. V.

    2015-01-01

    From the point of view of energy security, nuclear industry in Ukraine has quite a lot of potential: availability of own raw uranium resources, domestic production of equipment for nuclear power plants, monitoring and control systems for nuclear power plants, design and construction organizations, energy engineering; availability of human resources, personnel training, experience with NPP, the infrastructure to support the operation of nuclear power plants; preservation of low CO 2 emissions. The Ukrainian government considers the priority development of nuclear industry as one of the most urgent tasks at the current stage of development Ukrainian fuel and energy complex, which will be enshrined in the Energy Strategy of Ukraine until 2035, which is in the stage of adoption

  15. Lake whitefish diet, condition, and energy density in Lake Champlain and the lower four Great Lakes following dreissenid invasions

    Science.gov (United States)

    Herbst, Seth J.; Marsden, J. Ellen; Lantry, Brian F.

    2013-01-01

    Lake Whitefish Coregonus clupeaformis support some of the most valuable commercial freshwater fisheries in North America. Recent growth and condition decreases in Lake Whitefish populations in the Great Lakes have been attributed to the invasion of the dreissenid mussels, zebra mussels Dreissena polymorpha and quagga mussels D. bugensis, and the subsequent collapse of the amphipod, Diporeia, a once-abundant high energy prey source. Since 1993, Lake Champlain has also experienced the invasion and proliferation of zebra mussels, but in contrast to the Great Lakes, Diporeia were not historically abundant. We compared the diet, condition, and energy density of Lake Whitefish from Lake Champlain after the dreissenid mussel invasion to values for those of Lake Whitefish from Lakes Michigan, Huron, Erie, and Ontario. Lake Whitefish were collected using gill nets and bottom trawls, and their diets were quantified seasonally. Condition was estimated using Fulton's condition factor (K) and by determining energy density. In contrast to Lake Whitefish from some of the Great Lakes, those from Lake Champlain Lake Whitefish did not show a dietary shift towards dreissenid mussels, but instead fed primarily on fish eggs in spring, Mysis diluviana in summer, and gastropods and sphaeriids in fall and winter. Along with these dietary differences, the condition and energy density of Lake Whitefish from Lake Champlain were high compared with those of Lake Whitefish from Lakes Michigan, Huron, and Ontario after the dreissenid invasion, and were similar to Lake Whitefish from Lake Erie; fish from Lakes Michigan, Huron, and Ontario consumed dreissenids, whereas fish from Lake Erie did not. Our comparisons of Lake Whitefish populations in Lake Champlain to those in the Great Lakes indicate that diet and condition of Lake Champlain Lake Whitefish were not negatively affected by the dreissenid mussel invasion.

  16. Performance analysis of hybrid photovoltaic/diesel energy system under Malaysian conditions

    International Nuclear Information System (INIS)

    Lau, K.Y.; Yousof, M.F.M.; Arshad, S.N.M.; Anwari, M.; Yatim, A.H.M.

    2010-01-01

    Standalone diesel generating system utilized in remote areas has long been practiced in Malaysia. Due to highly fluctuating diesel price, such a system is seemed to be uneconomical, especially in the long run if the supply of electricity for rural areas solely depends on such diesel generating system. This paper would analyze the potential use of hybrid photovoltaic (PV)/diesel energy system in remote locations. National Renewable Energy Laboratory's (NREL) HOMER software was used to perform the techno-economic feasibility of hybrid PV/diesel energy system. The investigation demonstrated the impact of PV penetration and battery storage on energy production, cost of energy and number of operational hours of diesel generators for the given hybrid configurations. Emphasis has also been placed on percentage fuel savings and reduction in carbon emissions of different hybrid systems. At the end of this paper, suitability of utilizing hybrid PV/diesel energy system over standalone diesel system would be discussed mainly based on different solar irradiances and diesel prices. (author)

  17. Designing of the Low Energy Beam Lines with Achromatic Condition in the RAON Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hyunchang; Jang, Ji-Ho; Jeon, Dong-O [Institute for Basic Science, Daejeon (Korea, Republic of)

    2017-01-15

    The RAON accelerator has been built to create and accelerate stable heavy-ion beams and rare isotope beams. The stable heavy-ion beams are generated by the superconducting electron cyclotron resonance ion source and accelerated by the low energy superconducting linac SCL1. The beams accelerated by the SCL1 are re-accelerated by the high energy superconducting linac SCL2 for the generation of rare isotope beams by using the in-flight fragmentation system or are put to use in the low energy experimental halls, which include the neutron science facility and the Korea Broad acceptance Recoil spectrometer and Apparatus after having passed through the low energy beam lines which have long deflecting sections. At the end of each beam line in the low energy experimental halls, the beams should meet the targets of the two facilities with the specific requirements satisfied. Namely, if the beam is to be sent safely and accurately to the targets and simultaneously, satisfy the requirements, an achromatic lattice design needs to be applied in each beam line. In this paper, we will present the lattice design of the low energy beam lines and describe the results of the beam dynamics simulations. In addition, the correction of the beam orbit, which is distorted by machine imperfections, will be discussed.

  18. Legal boundary conditions of the waste management and energy industry; Rechtliche Rahmenbedingungen der Abfall- und Energiewirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Brahms, Florian [Maslaton Rechtsanwaltsgesellschaft mbH, Leipzig (Germany)

    2013-10-01

    The legal framework of waste and energy management was subject to significant transformations which find their legal link of the national state objective to protect the natural resources for future generations in Article 20a of the German constitution. The waste law as well as the energy law aim at the efficient use of resources to protect the environment and smooth the way for a CO{sub 2}-neutral society. After the accident at Fukushima on 11 March 2011 the legislator enacted a number of laws that have a lasting impact on the energy industry and that the operators of biomass plants have to adapt to. At the same time, renewable energies have achieved a remarkable market share under the German Renewable Energy Act, so that market and system integration has also moved into the foreground of the legislation. For electricity produced from the fermentation of biowaste, the German Renewable Energy Act 2012 already provides that the fixed feed-in compensation for installations with an electrical power over 750 kW commissioned after 31 December 2013 no longer exists. The waste legislation is characterized in particular by its relation to European laws, although the definition of the term ''waste'' still causes demarcation difficulties. The Biowaste Ordinance was comprehensively amended in April 2012 in consideration of a number of European regulations. (orig.)

  19. Main trends of energy savings in dwelling houses for Lithuanian conditions

    Energy Technology Data Exchange (ETDEWEB)

    Stankevicius, V.; Karbauskaite, J.; Dapkus, G. [Institute of Architecture and construction (Lithuania)

    1995-12-31

    Incentive measures for efficient consumption of energy in buildings in Lithuania, were presented. Statistics have shown that the average annual building heat losses are 350 kW/sq.m of heated area. It was estimated, that if every building was insulated according to the requirements of the Lithuanian National Building Code, the annual energy savings would be in the order of 50 to 60 percent. Essential energy saving measures with due regard to Lithuania`s current financial and technical resources were detailed. It was suggested that installing energy efficient windows would be the cheapest and most effective measure to begin energy conservation. The addition of effective insulation of external walls would be a favoured but more costly measure, especially as far as insulating existing houses is concerned. The pay-back period of adding extra insulation was also described, although this option is not of the highest priority. It was suggested that a system of special incentives, if offered by the Lithuanian government, could prove to be powerful motivators to carry out these energy saving measures. 2 tabs., 1 fig.

  20. Energy performance of supermarket refrigeration and air conditioning integrated systems working with natural refrigerants

    International Nuclear Information System (INIS)

    Cecchinato, Luca; Corradi, Marco; Minetto, Silvia

    2012-01-01

    The current trends in commercial refrigeration aim at reducing the synthetic refrigerant charge, either by minimising the internal volume of the circuit or by utilising natural refrigerants, and at energy saving. The energy efficiency of supermarkets can be improved by optimising components design, recovering thermal and refrigerating energy, adopting innovative technology solutions, integrating the HVAC system with medium temperature and low temperature refrigeration plants and, finally, reducing thermal loads on refrigerated cases. This study aims at investigating the performance of different lay-out and technological solutions where only natural refrigerants are used and at finding the potential for improving energy efficiency over the traditional systems in different climates. In the analysis, chillers and heat pumps working with ammonia or propane, medium temperature systems working with ammonia or propane and carbon dioxide as heat transfer fluid or with carbon dioxide as the refrigerant and low temperature systems working with carbon dioxide are considered and benchmarked with a state-of-the-art HFCs based plant. The most efficient investigated solution enables an annual energy saving higher than 15% with respect to the baseline solution for all the considered climates. - Highlights: ► Different natural refrigerants supermarket HVAC and R integrated systems are analysed. ► Some of the proposed solutions offer a significant benefit over the baseline one. ► Up to 18.7% energy saving is achieved in the considered climates. ► The refrigeration unit condensation by the AC chiller offers the poorest results.

  1. Effects of prepartal body condition score and peripartal energy supply of dairy cows on postpartal lipolysis, energy balance and ketogenesis: an animal model to investigate subclinical ketosis.

    Science.gov (United States)

    Schulz, Kirsten; Frahm, Jana; Meyer, Ulrich; Kersten, Susanne; Reiche, Dania; Rehage, Jürgen; Dänicke, Sven

    2014-08-01

    Subclinical ketosis is a metabolic disorder which often goes undiagnosed and leads to constricted performance and an impairment of general condition. In the current study subclinical ketosis was characterised by a β-hydroxybutyrate (BHB) concentration of >1·2 mmol/l in blood serum. To generate this metabolic situation, an animal model was created. The model, based on group-specific interaction of dietary energy supply and body condition, is appropriate for testing the medical effectiveness of treating this kind of ketosis and its concomitants. During the trial, 18 dairy cows (primiparous and pluriparous) were assigned, according to their body condition score (BCS) 6 weeks before expected parturition, to a normal [6.78 MJ net energy for lactation (NEL)/kg dry matter; 20% concentrate] or to a high-energy feeding group (7·71 MJ NEL/kg dry matter; 60% concentrate). Therefore cows with the highest BCS were allocated to the high-energy group to enhance the contrast with the control group. Statistical analysis was done using the MIXED procedure of SAS. Effects were declared significant when P-values were ⩽0.05. Owing to the higher energy concentration and dry matter intake, the energy intake and balance was significantly higher in the high-energy feeding group, with strong effects on lipid metabolism and health in blood and liver post partum. Within the first 2 weeks after calving, 8 out of 9 cows (89%) of the high-energy group had BHB values indicative of subclinical ketosis. These cows also had significantly higher values of non-esterified fatty acids (NEFA), aspartate transaminase (AST) and glutamate dehydrogenase (GLDH) post partum, as well as a raised total lipid content of the liver. RQUICKI, a calculated parameter which is based on serum concentrations of glucose, insulin and NEFA to assess the insulin sensitivity, was not affected by treatment. Therefore, RQUICKI does not seem to be the right parameter for diagnosing decreased insulin sensitivity in cows

  2. An energy-stable method for solving the incompressible Navier-Stokes equations with non-slip boundary condition

    Science.gov (United States)

    Lee, Byungjoon; Min, Chohong

    2018-05-01

    We introduce a stable method for solving the incompressible Navier-Stokes equations with variable density and viscosity. Our method is stable in the sense that it does not increase the total energy of dynamics that is the sum of kinetic energy and potential energy. Instead of velocity, a new state variable is taken so that the kinetic energy is formulated by the L2 norm of the new variable. Navier-Stokes equations are rephrased with respect to the new variable, and a stable time discretization for the rephrased equations is presented. Taking into consideration the incompressibility in the Marker-And-Cell (MAC) grid, we present a modified Lax-Friedrich method that is L2 stable. Utilizing the discrete integration-by-parts in MAC grid and the modified Lax-Friedrich method, the time discretization is fully discretized. An explicit CFL condition for the stability of the full discretization is given and mathematically proved.

  3. Genetic parameters for energy balance, fat /protein ratio, body condition score and disease traits in German Holstein cows.

    Science.gov (United States)

    Buttchereit, N; Stamer, E; Junge, W; Thaller, G

    2012-08-01

    Various health problems in dairy cows have been related to the magnitude and duration of the energy deficit post partum. Energy balance indicator traits like fat/protein ratio in milk and body condition score could be used in selection programmes to help predicting breeding values for health traits, but currently there is a lack of appropriate genetic parameters. Therefore, genetic correlations among energy balance, fat/protein ratio, and body condition score, and mastitis, claw and leg diseases, and metabolic disorders were estimated using linear and threshold models on data from 1693 primiparous cows recorded within the first 180 days in milk. Average daily energy balance, milk fat/protein ratio and body condition score were 8 MJ NEL, 1.13 and 2.94, respectively. Disease frequencies (% cows with at least one case) were 24.6% for mastitis, 9.7% for metabolic disorders and 28.2% for claw and leg diseases. Heritability estimates were 0.06, 0.30 and 0.34 for energy balance, fat/protein ratio and body condition score, respectively. For the disease traits, heritabilities ranged between 0.04 and 0.15. The genetic correlations were, in general, associated with large standard errors, but, although not significant, the results suggest that an improvement of overall health can be expected if energy balance traits are included into future breeding programmes. A low fat/protein ratio might serve as an indicator for metabolic stability and health of claw and legs. Between body condition and mastitis, a significant negative correlation of -0.40 was estimated. The study provides a new insight into the role energy balance traits can play as auxiliary traits for robustness of dairy cows. It was concluded that both, fat/protein ratio and body condition score, are potential variables to describe how well cows can adapt to the challenge of early lactation. However, the genetic parameters should be re-estimated on a more comprehensive data set. © 2011 Blackwell Verlag GmbH.

  4. Present developmental conditions of petroleum substituting energies in the U.S.A; Sekiyu daitai energy no kaihatsu no genjo (Beikoku)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The present developmental conditions of petroleum substituting energies in the U.S.A. were surveyed. The budget related to energy saving and petroleum substituting energies in the U.S.A. is on the increase. DOE`s expenditure on petroleum substituting energies increased from $6.8 billion in 1993 to $8.1 billion in 1995 (from 29.6% to 34.6% of DOE`s expenditure), showing the positive approach to development of petroleum substituting energies. Approaches to environmental protection are also in promotion such as positive use of electrical vehicles by U.S. government and emission regulation of specific pollutants by EPA. The state of California withdrew the regulation which prescribes that 2% of passenger cars sold in the state should be zero emission vehicles after 1998, because development of the battery with both sufficient mileage and output is impossible by 1998 in the present stage. The prospect of practical use of new batteries such as lithium battery is still far from certain for some years. Development of petroleum substituting energies in the U.S.A. is still insufficient. 17 refs., 1 fig., 4 tabs.

  5. Hybrid centralized-distributed power conditioning system for thermoelectric generator with high energy efficiency

    DEFF Research Database (Denmark)

    Wu, Hongfei; Sun, Kai; Chen, Min

    2013-01-01

    the proposed system, which benefits for implementing high MPPT efficiency and high conversion efficiency simultaneously. A hybrid MPPT control strategy is proposed for this HCD power conditioning system. The characteristics, circuit implementation and operation principles of the proposed system are presented......-distributed (HCD) power conditioning system for TEG and its control strategy are proposed in this paper. The HCD power conditioning system is composed by a centralized power conversion stage and multiple distributed power conversion stages. Most of the power is processed by the centralized power conversion stage...

  6. Energy Taxis Drives Campylobacter jejuni toward the Most Favorable Conditions for Growth

    DEFF Research Database (Denmark)

    Vegge, C.S.; Brondsted, L.; Li, Yiping

    2009-01-01

    Campylobacter jejuni is a serious food-borne bacterial pathogen in the developed world. Poultry is a major reservoir, and C. jejuni appears highly adapted to the gastrointestinal tract of birds. Several factors are important for chicken colonization and virulence, including a taxis mechanism...... identified as new attractants of C. jejuni, and we observed that chemical substances promoting tactic attraction are all known to support the growth of this organism. The attractants could be categorized as carbon sources and electron donors and acceptors, and we furthermore observed a correlation between...... an attractant's potency and its efficiency as an energy source. The tactic attraction was inhibited by the respiratory inhibitors HQNO (2-n-heptyl-4-hydroxyquinoline N-oxide) and sodium azide, which significantly reduce energy production by oxidative phosphorylation. These findings strongly indicate that energy...

  7. High energy x-ray and neutron studies of disordered energy-related materials at extreme conditions

    International Nuclear Information System (INIS)

    Parise, John

    2016-01-01

    The fundamental scientific accomplishments are: (1) advances in a general description of the liquid state by employing structural models constrained by measurements to interpret experimental results and extend them to liquids in general, with special emphasis on (2) The structure of the high-temperature crystal and molten UO_2 and 3) water. Specifically, samples of UO_2 and water were probed using high-energy x-rays at the Advanced Photon Source. The high Z of UO_2, and the 2-3mm diameter droplet shape of the molten sample, means that >100keV X-rays are required to minimize absorption and multiple scattering, which can distort the measured structure factor. A high flux of x-rays is also required to obtain sufficient statistical accuracy in short (a few seconds) measurement times. The scattered x-ray data were analyzed and pair distribution functions, extracted that characterize the local and long-range atomic structure of the material. The measurements of the hot UO_2 solid show a substantial increase in oxygen disorder and, upon melting, the average U-O coordination was found to decrease from 8 to 6.7±0.5. The research incorporated development of diffraction techniques, sample environment optimization and state-of-the-art simulation techniques. The symbiotic nature of the advances in simulation and experiment allowed for a more focused and informed development of future experiments, effective use of expensive beam time and generated new research agendas for the growing number of research groups, within the US and internationally, that focus on the structure of liquids. Molecular dynamics (MD) provided detailed information when combined with high-quality XN data including addressing key issues in liquids; the relationship between cooling path, structure and fictive temperature, and the trade-offs between network over connectedness in liquids containing low-coordination cations.

  8. Mechanical energy release and fuel fragmentation in high energy deposition into fuel under a reactivity initiated accident condition

    International Nuclear Information System (INIS)

    Tsuruta, Takaharu; Saito, Shinzo; Ochiai, Masaaki

    1985-01-01

    The fuel fragmentation is one of important subjects to be studied, since it is one of basic processes of molten fuel-coolant interaction (MFCI) and it has not yet been made clear enough. Accordingly, UO 2 fuel fragmentation was studied in the NSRR experiments simulating a reactivity initiated accident (RIA). As results of the experiments, the distribution of the size of fuel fragments was obtained and the mechanism of fuel fragmentation was discussed as described below. It was revealed that the distribution was well displayed in the form of logarithmic Rosin-Rammler's distribution law. It was shown that the conversion ratio from thermal energy to mechanical in the experiment was in inverse propotion to the volume-surface mean diameter defined as a ratio of the total volume of fragments to the total surface. Consequently, it was confirmed that the mean diameter was proper as an index for the degree of the fuel fragmentation. It was also pointed out that the Weber-type hydraulic instability model for fragmentation was consistent with the experimental results. The mechanism of the fuel fragmentation is understood as follows. Cladding tube is ruptured due to the increase in rod pressure when fuel is molten, and then molten fuel spouts through the openings in the form of jet. As a result of molten fuel spouting, fuel is fragmented by the Weber-type of hydraulic instability. The model well explains the effects of experimental parameters as heat deposition, subcooling of cooling water and capsule diameter, on the fuel fragmentation. According to the model, fuel fragments have to be spherical. There were many spherical particles which had hollow and burst crack. This may be due to internal burst during solidification process. The items which should be studied further are also described in the end of this report. (author)

  9. High energy x-ray and neutron studies of disordered energy-related materials at extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Parise, John [Stony Brook Univ., NY (United States)

    2016-05-16

    The fundamental scientific accomplishments are: (1) advances in a general description of the liquid state by employing structural models constrained by measurements to interpret experimental results and extend them to liquids in general, with special emphasis on (2) The structure of the high-temperature crystal and molten UO2 and 3) water. Specifically, samples of UO2 and water were probed using high-energy x-rays at the Advanced Photon Source. The high Z of UO2, and the 2-3mm diameter droplet shape of the molten sample, means that >100keV X-rays are required to minimize absorption and multiple scattering, which can distort the measured structure factor. A high flux of x-rays is also required to obtain sufficient statistical accuracy in short (a few seconds) measurement times. The scattered x-ray data were analyzed and pair distribution functions, extracted that characterize the local and long-range atomic structure of the material. The measurements of the hot UO2 solid show a substantial increase in oxygen disorder and, upon melting, the average U-O coordination was found to decrease from 8 to 6.7±0.5. The research incorporated development of diffraction techniques, sample environment optimization and state-of-the-art simulation techniques. The symbiotic nature of the advances in simulation and experiment allowed for a more focused and informed development of future experiments, effective use of expensive beam time and generated new research agendas for the growing number of research groups, within the US and internationally, that focus on the structure of liquids. Molecular dynamics (MD) provided detailed information when combined with high-quality XN data including addressing key issues in liquids; the relationship between cooling path, structure and fictive temperature, and the trade-offs between network over connectedness in liquids containing low-coordination cations.

  10. A model of residential energy end-use in Canada: Using conditional demand analysis to suggest policy options for community energy planners

    International Nuclear Information System (INIS)

    Newsham, Guy R.; Donnelly, Cara L.

    2013-01-01

    We applied conditional demand analysis (CDA) to estimate the average annual energy use of various electrical and natural gas appliances, and derived energy reductions associated with certain appliance upgrades and behaviours. The raw data came from 9773 Canadian households, and comprised annual electricity and natural gas use, and responses to >600 questions on dwelling and occupant characteristics, appliances, heating and cooling equipment, and associated behaviours. Replacing an old (>10 years) refrigerator with a new one was estimated to save 100 kW h/year; replacing an incandescent lamp with a CFL/LED lamp was estimated to save 20 kW h/year; and upgrading an old central heating system with a new one was estimated to save 2000 kW h/year. This latter effect was similar to that of reducing the number of walls exposed to the outside. Reducing the winter thermostat setpoint during occupied, waking hours was estimated to lower annual energy use by 200 kW h/°C-reduction, and lowering the thermostat setting overnight in winter relative to the setting during waking hours (night-time setback) was estimated to have a similar effect. This information may be used by policy-makers to optimize incentive programs, information campaigns, or other energy use change instruments. - Highlights: ► Conditional demand analysis (CDA) applied to data from 9773 Canadian households. ► Energy savings associated with certain appliance upgrades estimated. ► Energy savings associated with thermostat behaviours estimated. ► Policy-makers can use findings to optimize incentives and information campaigns

  11. Energy Savings Potential and Research, Development, & Demonstration Opportunities for Residential Building Heating, Ventilation, and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Inc., Burlington, MA (United States); Zogg, Robert [Navigant Consulting, Inc., Burlington, MA (United States); Young, Jim [Navigant Consulting, Inc., Burlington, MA (United States); Schmidt, Justin [Navigant Consulting, Inc., Burlington, MA (United States)

    2012-10-01

    This report is an assessment of 135 different heating, ventilation, and air-conditioning (HVAC) technologies for U.S. residential buildings to identify and provide analysis on 19 priority technology options in various stages of development. The analyses include an estimation of technical energy-savings potential, descriptions of technical maturity, descriptions of non-energy benefits, descriptions of current barriers for market adoption, and descriptions of the technology's applicability to different building or HVAC equipment types. From these technology descriptions, are suggestions for potential research, development and demonstration (RD&D) initiatives that would support further development of the priority technology options.

  12. Energy Savings Potential and Research, Development, & Demonstration Opportunities for Commercial Building Heating, Ventilation, and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-09-01

    This report covers an assessment of 182 different heating, ventilation, and air-conditioning (HVAC) technologies for U.S. commercial buildings to identify and provide analysis on 17 priority technology options in various stages of development. The analyses include an estimation of technical energy-savings potential, description of technical maturity, description of non-energy benefits, description of current barriers for market adoption, and description of the technology’s applicability to different building or HVAC equipment types. From these technology descriptions, are suggestions for potential research, development and demonstration (RD&D) initiatives that would support further development of the priority technology options.

  13. Annual energy yield of different photovoltaic technologies at different climatic conditions; Jahresenergieertraege unterschiedlicher Photovoltaik-Technologien bei verschiedenen klimatischen Bedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Zinsser, Bastian

    2010-10-04

    It is very important for engineers as well as for investors to know which amount of energy E [kWh] a photovoltaic (PV) system produces under real operating conditions. In most cases the costs [Euroct/kWh] for the solar electricity are the main question. Most data sheets contain the efficiency of the PV modules only for standard test conditions (STC) in the laboratory. In reality higher module temperatures, lower irradiation G and a modified spectrum of the irradiation G change the standard test conditions efficiency. However, standard test conditions never appear at real live in Germany. In southern countries, which have more sun, the operation conditions differ much more from standard test conditions. Therefore, the effects on the annual energy yield are even bigger. To answer the question which PV technology gives the highest energy yield at specific climate conditions, this thesis set up thirteen PV systems using different technologies in Stuttgart, Nicosia, and Cairo. An extensive data acquisition is added to monitor weather and system data. Mono- and multicrystalline silicon (Si) as well as several thin film technologies like amorphous silicon, Cu(InGa)Se{sub 2} (CIGS), and CdTe are investigated. First the thesis extracts the temperature and low light behavior from the measured field data. At the end it models the PV systems to forecast the annual energy yield EJahr and compares with the measured values. The analysis of the field data reconfirms the better temperature behavior of the thin film technologies reported in literature. The HIT technology exhibits a better low light behavior, than the crystalline Si technologies, which all show a similar low light behavior. In the field the CIGS technology shows a contrary low light behavior compared to the laboratory. Field data show, that amorphous Si and CdTe technologies have a much better low light behavior than the crystalline Si technologies. The tolerances of the nominal power PSTC have the biggest influence

  14. Operation of Dokan Reservoir under Stochastic Conditions as Regards the Inflows and the Energy Demands

    Science.gov (United States)

    Rashed, G. I.

    2018-02-01

    This paper presented a way of obtaining certain operating rules on time steps for the management of a large reservoir operation with a peak hydropower plant associated to it. The rules were allowed to have the form of non-linear regression equations which link a decision variable (here the water volume in the reservoir at the end of the time step) by several parameters influencing it. This paper considered the Dokan hydroelectric development KR-Iraq, which operation data are available for. It was showing that both the monthly average inflows and the monthly power demands are random variables. A model of deterministic dynamic programming intending the minimization of the total amount of the squares differences between the demanded energy and the generated energy is run with a multitude of annual scenarios of inflows and monthly required energies. The operating rules achieved allow the efficient and safe management of the operation and it is quietly and accurately known the forecast of the inflow and of the energy demand on the next time step.

  15. Use of ordinary kriging and Gaussian conditional simulation to interpolate airborne fire radiative energy density estimates

    Science.gov (United States)

    C. Klauberg; A. T. Hudak; B. C. Bright; L. Boschetti; M. B. Dickinson; R. L. Kremens; C. A. Silva

    2018-01-01

    Fire radiative energy density (FRED, J m-2) integrated from fire radiative power density (FRPD, W m-2) observations of landscape-level fires can present an undersampling problem when collected from fixed-wing aircraft. In the present study, the aircraft made multiple passes over the fire at ~3 min intervals, thus failing to observe most of the FRPD emitted as the flame...

  16. Optimal energy management for a mechanical-hybrid vehicle with cold start conditions

    NARCIS (Netherlands)

    Berkel, van K.; Klemm, W.P.A.; Hofman, T.; Vroemen, B.G.; Steinbuch, M.

    2013-01-01

    This paper presents the design of an optimal Energy Management Strategy (EMS) for a hybrid vehicle that starts with a cold powertrain. The cold start negatively affects the combustion and transmission efficiency of the powertrain, caused by the higher frictional losses due to increased hydrodynamic

  17. Dokan Hydropower Reservoir Operation under Stochastic Conditions as Regards the Inflows and the Energy Demands

    Science.gov (United States)

    Izat Rashed, Ghamgeen

    2018-03-01

    This paper presented a way of obtaining certain operating rules on time steps for the management of a large reservoir operation with a peak hydropower plant associated to it. The rules were allowed to have the form of non-linear regression equations which link a decision variable (here the water volume in the reservoir at the end of the time step) by several parameters influencing it. This paper considered the Dokan hydroelectric development KR-Iraq, which operation data are available for. It was showing that both the monthly average inflows and the monthly power demands are random variables. A model of deterministic dynamic programming intending the minimization of the total amount of the squares differences between the demanded energy and the generated energy is run with a multitude of annual scenarios of inflows and monthly required energies. The operating rules achieved allow the efficient and safe management of the operation and it is quietly and accurately known the forecast of the inflow and of the energy demand on the next time step.

  18. IMPACT OF THE COLD END OPERATING CONDITIONS ON ENERGY EFFICIENCY OF THE STEAM POWER PLANTS

    Directory of Open Access Journals (Sweden)

    Slobodan Laković

    2010-01-01

    Full Text Available The conventional steam power plant working under the Rankine Cycle and the steam condenser as a heat sink and the steam boiler as a heat source have the same importance for the power plant operating process. Energy efficiency of the coal fired power plant strongly depends on its turbine-condenser system operation mode. For the given thermal power plant configuration, cooling water temperature or/and flow rate change generate alterations in the condenser pressure. Those changes have great influence on the energy efficiency of the plant. This paper focuses on the influence of the cooling water temperature and flow rate on the condenser performance, and thus on the specific heat rate of the coal fired plant and its energy efficiency. Reference plant is working under turbine-follow mode with an open cycle cooling system. Analysis is done using thermodynamic theory, in order to define heat load dependence on the cooling water temperature and flow rate. Having these correlations, for given cooling water temperature it is possible to determine optimal flow rate of the cooling water in order to achieve an optimal condensing pressure, and thus, optimal energy efficiency of the plant. Obtained results could be used as useful guidelines in improving existing power plants performances and also in design of the new power plants.

  19. A material optimization model to approximate energy bounds for cellular materials under multiload conditions

    DEFF Research Database (Denmark)

    Guedes, J.M.; Rodrigues, H.C.; Bendsøe, Martin P.

    2003-01-01

    This paper describes a computational model, based on inverse homogenization and topology design, for approximating energy bounds for two-phase composites under multiple load cases. The approach allows for the identification of possible single-scale cellular materials that give rise to the optimal...

  20. A Low-energy Building under Arctic Conditions - Experiences After Five Years of Operation

    DEFF Research Database (Denmark)

    Rode, Carsten; Vladyková, Petra; Kotol, Martin

    2011-01-01

    In 2005, a low energy house was inaugurated in Sisimiut, Greenland. The house and the plans with it were presented at the third International Building Physics Conference in 2006. The house is characterised by having a highly insulated building envelope which is almost free of thermal bridges, adv...

  1. Thermal Energy Storage for the Small Packaged Terminal Air Conditioning Unit. Quarterly progress report, February 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    To finalize the IceBear design for full-scale production, build two preproduction prototypes, and confirm cost projections for production and market analysis. The 5 tasks being carried out are: Task 1--Finalize thermal energy storage tank design; Task 2--Finalize internal heat exchanger; Task 3--Finalize refrigerant management and control components; Task 4--Preproduction prototype laboratory testing; and Task 5--Reporting.

  2. Reduced-order modeling of piezoelectric energy harvesters with nonlinear circuits under complex conditions

    Science.gov (United States)

    Xiang, Hong-Jun; Zhang, Zhi-Wei; Shi, Zhi-Fei; Li, Hong

    2018-04-01

    A fully coupled modeling approach is developed for piezoelectric energy harvesters in this work based on the use of available robust finite element packages and efficient reducing order modeling techniques. At first, the harvester is modeled using finite element packages. The dynamic equilibrium equations of harvesters are rebuilt by extracting system matrices from the finite element model using built-in commands without any additional tools. A Krylov subspace-based scheme is then applied to obtain a reduced-order model for improving simulation efficiency but preserving the key features of harvesters. Co-simulation of the reduced-order model with nonlinear energy harvesting circuits is achieved in a system level. Several examples in both cases of harmonic response and transient response analysis are conducted to validate the present approach. The proposed approach allows to improve the simulation efficiency by several orders of magnitude. Moreover, the parameters used in the equivalent circuit model can be conveniently obtained by the proposed eigenvector-based model order reduction technique. More importantly, this work establishes a methodology for modeling of piezoelectric energy harvesters with any complicated mechanical geometries and nonlinear circuits. The input load may be more complex also. The method can be employed by harvester designers to optimal mechanical structures or by circuit designers to develop novel energy harvesting circuits.

  3. Thermal energy recovery of air conditioning system--heat recovery system calculation and phase change materials development

    International Nuclear Information System (INIS)

    Gu Zhaolin; Liu Hongjuan; Li Yun

    2004-01-01

    Latent heat thermal energy storage systems can be used to recover the rejected heat from air conditioning systems, which can be used to generate low-temperature hot water. It decreases not only the consumption of primary energy for heating domestic hot water but also the calefaction to the surroundings due to the rejection of heat from air conditioning systems. A recovery system using phase change materials (PCMs) to store the rejected (sensible and condensation) heat from air conditioning system has been developed and studied, making up the shortage of other sensible heat storage system. Also, PCMs compliant for heat recovery of air conditioning system should be developed. Technical grade paraffin wax has been discussed in this paper in order to develop a paraffin wax based PCM for the recovery of rejected heat from air conditioning systems. The thermal properties of technical grade paraffin wax and the mixtures of paraffin wax with lauric acid and with liquid paraffin (paraffin oil) are investigated and discussed, including volume expansion during the phase change process, the freezing point and the heat of fusion

  4. A note on the conditional correlation between energy prices: Evidence from future markets

    International Nuclear Information System (INIS)

    Marzo, Massimiliano; Zagaglia, Paolo

    2008-01-01

    We model the joint movements of daily returns on one-month futures for crude oil, heating oil and natural gas through the multivariate GARCH with dynamic conditional correlations and elliptical distributions introduced by Pelagatti and Rondena [Pelagatti, M.M., Rondena, S., 2007. 'Dynamic Conditional Correlation with Elliptical Distributions', unpublished manuscript. Universita di Milano - Bicocca, August]. Futures prices of crude and heating oil covary strongly. The conditional correlation between the futures prices of natural gas and crude oil has been rising over the last 5 years. However, this correlation has been low on average over two thirds of the sample, suggesting that future markets have no established tradition of pricing natural gas as a function of developments on oil markets. (author)

  5. ENERGY AND PROTEIN REQUIREMENTS OF GROWING PELIBUEY SHEEP UNDER TROPICAL CONDITIONS ESTIMATED FROM A LITERATURE DATABASE ANALYSES

    Directory of Open Access Journals (Sweden)

    Fernando Duarte

    2012-01-01

    Full Text Available Data from previous studies were used to estimate the metabolizable energy and protein requirements for maintenance and growth and basal metabolism energy requirement of male Pelibuey sheep under tropical conditions were estimated. In addition, empty body weight and mature weight of males and female Pelibuey sheep were also estimated. Basal metabolism energy requirements were estimated with the Cornell Net Carbohydrate and Protein System – Sheep (CNCPS-S model using the a1 factor of the maintenance equation. Mature weight was estimated to be 69 kg for males and 45 kg for females. Empty body weight was estimated to be 81% of live weight. Metabolizable energy and protein requirements for growth were 0.106 Mcal MEm/kg LW0.75 and 2.4 g MP/kg LW0.75 for males. The collected information did not allowed appropriate estimation of female requirements. The basal metabolism energy requirement was estimated to be 0.039 Mcal MEm/kg LW0.75. Energy requirements for basal metabolism were lower in Pelibuey sheep than those reported for wool breeds even though their total requirements were similar.

  6. The relationship between heating energy use, indoor temperature and heating energy demand under reference conditions in residential buildings

    Science.gov (United States)

    Magalhaes, Sara Moreira Coelho de

    etching. In this case, an excimer laser was used. Extremely thin fiber tips were obtained, with an ultra-high sensitivity to strain. The other technique employed to fabricate the fiber Bragg gratings was the point-by-point femtosecond laser inscription. In this case, the sensing elements are very stable at high temperatures and can be used to measure strain in harsh conditions. The employment of optical fiber lasers as sensing elements was also considered in this Thesis. Two laser cavities were studied, one based on the ring configuration and the other based on a figure-of-eight configuration. From these works, the quality of the laser emission, namely the signal-to-noise ratio, the reduced full-width at half maximum and the stability should be highlighted. These characteristics allowed the measurement of different physical parameters, such as strain, temperature and torsion. Lastly, the possibility to use microspheres as sensing elements was considered. Using the electric arc of a fusion splicer, it is possible to create microspheres at the tip of an optical fiber. Furthermore, with this technique it is chains of microspheres can be obtained, constituting Mach-Zehnder-type interferometers which are sensitive to physical parameters like strain and temperature. The preliminary results obtained by introducing silica microspheres in a support structure are also presented. In this case, the sensors were subjected to temperature variations. All the experimental work was combined with the respective theoretical considerations. Many questions have been raised with the course of this PhD, and there are still some without a definite answer. Thus, new research paths can be followed, having their basis grounded in the configurations here presented.

  7. Characteristics of Energy Transport of Li-conditioned and non-Li-conditioned Plasmas in the National Spherical Torus Experiment (NSTX)

    International Nuclear Information System (INIS)

    Ding, S.; Kaye, S.M.; Bell, R.E.; Kaita, R.; Kugel, H.; LeBlanc, B.P.; Paul, S.; Wan, B.

    2009-01-01

    The transport properties of NSTX plasmas obtained during the 2008 experimental campaign have been studied and are reported here. Transport trends and dependences have been isolated, and it is found that both electron and ion energy transport coefficients have strong dependences on local values of n(del)T, which in turn is strongly dependent on local current density profile. Without identifying this dependence, it is difficult to identify others, such as the dependence of transport coefficients on B p (or q), I p and P heat . In addition, a comparison between discharges with and without Lithium wall conditioning has been made. While the trends in the two sets of data are similar, the thermal transport loss, especially in the electron channel, is found to strongly depend on the amount of Lithium deposited, decreasing by up to 50% of its no-Lithium value.

  8. Energy policy for integrating the building environmental performance model of an air conditioned building in a subtropical climate

    International Nuclear Information System (INIS)

    Mui, K.W.

    2006-01-01

    For an air conditioned building, the major electricity consumption is by the heating, and air conditioning (HVAC) system. As energy saving strategies may be in conflict with the criteria of indoor air quality and thermal comfort, a concept of the building environmental performance model (BEPM) has been developed to optimize energy consumption in HVAC systems without any deterioration of the indoor air quality and thermal comfort. The BEPM is divided into two main modules: the adaptive comfort temperature (ACT) module and the new demand control ventilation (nDCV) module. This study aims to enhance and prompt the conventional operation of the air side systems by incorporating temperature reset with the adaptive comfort temperature control and the new demand control ventilation system in high rise buildings in Hong Kong. A new example weather year (1991) was established as a reference to compute the energy use of HVAC systems in buildings in order to obtain more representative data for predicting annual energy consumption. A survey of 165 Hong Kong office buildings was conducted and it provided valuable information on the existing HVAC design values in different grades of private commercial buildings in Hong Kong. It was found that the actual measured values of indoor temperature were lower than the design ones. Furthermore, with the new example weather year and the integration of the BEPM into Grade A private office buildings in Hong Kong, the total energy saving of the air conditioning systems was calculated (i.e. a saving of HK$122 million in electrical consumption per year) while the thermal comfort for the occupants was also maintained

  9. Net energy value of maize ethanol as a response to different climate and soil conditions in the southeastern USA

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Tomas; Garcia y Garcia, Axel; Paz, Joel O.; Hoogenboom, Gerrit [Department of Biological and Agricultural Engineering, 1109 Experiment Street, The University of Georgia, Griffin, GA 30223 (United States); Jones, James W. [Department of Agricultural and Biological Engineering, Frazier Rogers Hall, University of Florida, Gainesville, FL 32611 (United States)

    2009-08-15

    A recent increase in the demand for bio-ethanol has sparked maize production in the USA and other countries across the world. The net energy value (NEV), i.e. the energy output in ethanol and co-products after accounting for energy input requirements in the production chain of ethanol, is a measure of its sustainability. Grain yield of maize, which varies substantially across different climate and soil conditions, greatly impacts the ethanol NEV. The objectives of this study were to determine i) the NEV of ethanol produced from maize grown in four production regions in the southeastern USA and, ii) the specific impact of local soil variability under the same climate conditions within the four regions on the NEV of maize-ethanol. Maize yield was simulated with the Cropping System Model (CSM)-CERES-Maize model for soil and weather conditions, and management practices representing Bulloch, Floyd, Laurens and Mitchell counties, Georgia, USA. The calculation of ethanol NEV took into account the energy inputs and outputs of the entire ethanol production chain, and was based on the crop simulations. There were statistically significant differences in ethanol NEV among the counties, and within counties due to local soil variability. Differences in ethanol NEV among counties were partially due to different transportation distances. Based on the results of this study, it was concluded that maize-ethanol NEV can be increased by accounting for the soil and climate factors in the feedstock production and by locating ethanol-processing facilities in regions with soil and climate conditions that are favorable for ethanol-maize production. (author)

  10. Impact of climate change on commercial sector air conditioning energy consumption in subtropical Hong Kong

    International Nuclear Information System (INIS)

    Lam, Tony N.T.; Wan, Kevin K.W.; Wong, S.L.; Lam, Joseph C.

    2010-01-01

    Past and future trend of electricity use for air conditioning in the entire commercial sector in subtropical climates using 1979-2008 measured meteorological data as well as predictions for 2009-2100 from a general circulation model (MIROC3.2-H) was investigated. Air conditioning consumption showed an increasing trend over the past 30 years from 1979 to 2008. Principal component analysis (PCA) of measured and predicted monthly mean dry-bulb temperature, wet-bulb temperature and global solar radiation was conducted to determine a new climatic index Z for 1979-2008 and future 92 years (2009-2100) based on two emissions scenarios B1 and A1B (low and medium forcing). Through regression analysis, electricity use in air conditioning for the 92-year period was estimated. For low forcing, average consumption in 2009-2038, 2039-2068 and 2069-2100 would be, respectively, 5.7%, 12.8% and 18.4% more than the 1979-2008 average, with a mean 12.5% increase for the entire 92-year period. Medium forcing showed a similar increasing trend, but 1-4% more. Standard deviations of the monthly air conditioning consumption were found to be smaller suggesting possible reduction in seasonal variations in future years.

  11. Energy balance of a sparse coniferous high-latitude forest under winter conditions

    NARCIS (Netherlands)

    Gryning, S.E.; Batchvarova, E.; DeBruin, H.A.R.

    2001-01-01

    Measurements carried out in Northern Finland on radiation and turbulent fluxes over a sparse, sub-arctic boreal forest with snow covered ground were analysed. The measurements represent late winter conditions characterised by low solar elevation angles. During the experiment (12-24 March 1997) day

  12. Power conditioning system topology for grid integration of wind and fuell cell energy

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2006-12-01

    Full Text Available This paper shows the topology of the hybrid grid-connected power system and the performances of the front-end three-phase power inverter. The renewable sources of the hybrid power system consist of a solid oxide fuel cell and a wind-turbine. This type of combination is the most efficient one. The proposed topology benefits of the one common DC-AC inverter which injects the generated power into the grid. The architecture diminishes the cost of the power conditioning system. Moreover, due to the power balance control of the entire power conditioning system the bulk dc link electrolytic capacitor is replaced with a small plastic film one. The final power conditioning system has the following advantages: independent control of the reactive power, minimize harmonic current distortion offering a nearly unity power factor operation (0,998 operation capability, dc link voltage regulation (up to 5% ripple in the dc-link voltage in any operated conditions, fast disturbance compensation capability, high reliability, and low cost. The experimental test has been performed and the performances of the grid power inverter are shown.

  13. Subsurface Thermal Energy Storage for Improved Heating and Air Conditioning Efficiency

    Science.gov (United States)

    2016-11-21

    through water evaporation , although some cooling also occurs due to sensible heat transfer . Cooling towers are very effective heat transfer devices... evaporator coil connected to the building heating , ventilation, and air conditioning (HVAC) system. The refrigerant evaporates in the coil, removing...vapor is directed to a condensing coil, where the refrigerant vapor condenses back into a liquid, releasing its heat of vaporization. During

  14. In Vitro Disease Model of Microgravity Conditioning on Human Energy Metabolism

    Science.gov (United States)

    Snyder, Jessica; Culbertson, C.; Zhang, Ye; Emami, K.; Wu, H.; Sun, Wei

    2010-01-01

    NASA and its partners are committed to introducing appropriate new technology to enable learning and living safely beyond the Earth for extended periods of time in a sustainable and possibly indefinite manner. In the responsible acquisition of that goal, life sciences is tasked to tune and advance current medical technology to prepare for human health and wellness in the space environment. The space environment affects the condition and function of biological systems from organ level function to shape of individual organelles. The objective of this paper is to study the effect of microgravity on kinetics of drug metabolism. This fundamental characterization is meaningful to (1) scientific understanding of the response of biology to microgravity and (2) clinical dosing requirements and pharmacological thresholds during long term manned space exploration. Metabolism kinetics of the anti-nausea drug promethazine (PMZ) were determined by an in vitro ground model of 3-dimensional aggregates of human hepatocytes conditioned to weightlessness using a rotating wall bioreactor. The authors observed up-regulated PMZ conversion in model microgravity conditions and attribute this to effect to model microgravity conditioning acting on metabolic mechanisms of the cells. Further work is necessary to determine which particular cellular mechanisms are governing the experimental observations, but the authors conclude kinetics of drug metabolism are responsive to gravitational fields and further study of this sensitivity would improve dosing of pharmaceuticals to persons exposed to a microgravity environment.

  15. Work-family balance and energy : a day-level study on recovery conditions

    NARCIS (Netherlands)

    Sanz-Vergel, A.I.; Demerouti, E.; Moreno-Jiménez, B.; Mayo, M.

    2010-01-01

    The present study examines whether daily recovery inhibiting and enhancing conditions predict day-levels of work-family conflict (WFC), work-family facilitation (WFF), exhaustion and vigor. Forty-nine individuals from various professional backgrounds in Spain provided questionnaire and daily survey

  16. Work-Family Balance and Energy: A Day-Level Study on Recovery Conditions

    Science.gov (United States)

    Sanz-Vergel, Ana Isabel; Demerouti, Evangelia; Moreno-Jimenez, Bernardo; Mayo, Margarita

    2010-01-01

    The present study examines whether daily recovery inhibiting and enhancing conditions predict day-levels of work-family conflict (WFC), work-family facilitation (WFF), exhaustion and vigor. Forty-nine individuals from various professional backgrounds in Spain provided questionnaire and daily survey measures over a period of five working days.…

  17. Evaluation of Refrigerating and Air Conditioning Devices in Energy Cascade Systems under the Restriction of Carbon Dioxide Emissions

    Science.gov (United States)

    Shimazaki, Yoichi; Akisawa, Atsushi; Kashiwagi, Takao

    It is necessary to introduce energy cascade systems into the industrial sector in Japan to reduce carbon dioxide emissions. The aim of this study is to evaluate the refrigerating and air conditioning devices in cases of introducing both energy cascade systems and thermal recycling systems in industries located around urban areas. The authors have developed an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Limitation of carbon dioxide emissions results in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature one is shifted to refrigeration. It was found that increasing the amount of garbage combustor waste heat can reduce electric power for the turbo refrigerator by promoting waste heat driven ammonia absorption refrigerator.

  18. Evaluation of high-energy electron detectors for probing the inner magnetosphere under high-counting condition

    International Nuclear Information System (INIS)

    Tamada, Yukihiro; Takashima, Takeshi; Mitani, Takefumi; Miyake, Wataru

    2013-01-01

    An ERG (Energization and Radiation in Geospace) satellite will be launched to study the acceleration processes of energetic particles in the radiation belt surrounding the earth. It is very important to reveal the acceleration process of high-energy particles for both science and the application to space weather forecast. Drastic increases of high-energy electrons in the radiation belt is sometimes observed during a geomagnetic storm. When a large magnetic storm occurs, energetic electron count rates may exceed flux limits expected in the nominal design and large number of incident electrons leading to detection loss. The purpose of this study is to demonstrate that the count rate range of a single detection on board ERG satellite can be expanded by means of reading circuit operations to decrease an area of detection. In our ground experiment, we also found an unexpected result that count peaks shift to the higher energy side under high counting conditions. (author)

  19. Effect of moderate intakes of different tea catechins and caffeine on acute measures of energy metabolism under sedentary conditions

    DEFF Research Database (Denmark)

    Gregersen, N.T.; Bitz, C.; Krog-Mikkelsen, I.

    2009-01-01

    Green tea may stimulate energy metabolism; however, it is unclear if acute effects are caused by specific catechins, caffeine or their combination. The objective of the present study was to examine the separate and combined effects of different catechins and caffeine on energy expenditure (EE...... and fat oxidation. The maximum observed effect on EE of about 2 % could still be meaningful for energy balance over much longer period of exposure. However, higher short-term effects reported in the literature may reflect variations in green tea extracts, added caffeine, or synergies with physical...... activity. The specific mechanisms and conditions that may underpin observed longer-term benefits of catechin-enriched green tea consumption on body composition remain to be confirmed....

  20. A strategy for prioritising interactive measures for enhancing energy efficiency of air-conditioned buildings

    International Nuclear Information System (INIS)

    Lee, W.L.; Yik, F.W.H.; Jones, P.

    2003-01-01

    Within a given budget, selection of the optimal set of measures for enhancing the energy efficiency of a building is often based on the relative order of the feasible measures, prioritised according to either the life cycle cost saving or the economic benefit-cost ratio of the measures. A sensitivity analysis shows that, compared to the life cycle cost analysis, the benefit-cost ratio analysis is less susceptible to the influence of uncertainties in the estimates of the present value of the life cycle energy saving and cost. Where interactive measures are involved, the effects of some are dependent on the co-existence of other measures. The prioritisation determined according to the benefit-cost ratios of individual measures, each taken in the absence of all the others, can lead to the choice of a range of measures that is below optimal. Selection of the optimal set of energy efficiency enhancement measures requires a multistep approach, which is exemplified by the case study described in the paper

  1. A Porphyrin Complex as a Self-Conditioned Electrode Material for High-Performance Energy Storage.

    Science.gov (United States)

    Gao, Ping; Chen, Zhi; Zhao-Karger, Zhirong; Mueller, Jonathan E; Jung, Christoph; Klyatskaya, Svetlana; Diemant, Thomas; Fuhr, Olaf; Jacob, Timo; Behm, R Jürgen; Ruben, Mario; Fichtner, Maximilian

    2017-08-21

    The novel functionalized porphyrin [5,15-bis(ethynyl)-10,20-diphenylporphinato]copper(II) (CuDEPP) was used as electrodes for rechargeable energy-storage systems with an extraordinary combination of storage capacity, rate capability, and cycling stability. The ability of CuDEPP to serve as an electron donor or acceptor supports various energy-storage applications. Combined with a lithium negative electrode, the CuDEPP electrode exhibited a long cycle life of several thousand cycles and fast charge-discharge rates up to 53 C and a specific energy density of 345 Wh kg -1 at a specific power density of 29 kW kg -1 . Coupled with a graphite cathode, the CuDEPP anode delivered a specific power density of 14 kW kg -1 . Whereas the capacity is in the range of that of ordinary lithium-ion batteries, the CuDEPP electrode has a power density in the range of that of supercapacitors, thus opening a pathway toward new organic electrodes with excellent rate capability and cyclic stability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Multiple regression models for energy use in air-conditioned office buildings in different climates

    International Nuclear Information System (INIS)

    Lam, Joseph C.; Wan, Kevin K.W.; Liu Dalong; Tsang, C.L.

    2010-01-01

    An attempt was made to develop multiple regression models for office buildings in the five major climates in China - severe cold, cold, hot summer and cold winter, mild, and hot summer and warm winter. A total of 12 key building design variables were identified through parametric and sensitivity analysis, and considered as inputs in the regression models. The coefficient of determination R 2 varies from 0.89 in Harbin to 0.97 in Kunming, indicating that 89-97% of the variations in annual building energy use can be explained by the changes in the 12 parameters. A pseudo-random number generator based on three simple multiplicative congruential generators was employed to generate random designs for evaluation of the regression models. The difference between regression-predicted and DOE-simulated annual building energy use are largely within 10%. It is envisaged that the regression models developed can be used to estimate the likely energy savings/penalty during the initial design stage when different building schemes and design concepts are being considered.

  3. Technical and economical conditions of nuclear energy usage continuation in Lithuania

    International Nuclear Information System (INIS)

    Gylys, J.; Ziedelis, S.; Klevas, V.

    2005-01-01

    The main producer of electric energy in Lithuania is Ignalina NPP with its two RBMK-1500 type reactors. It covers up to 86% of total annual electricity production. The compulsory premature closure of Ignalina NPP due to the decision of EU authorities will decrease maximum power generating capacity to 3273 MW in the year 2010 (slump of 42% in respect to 5698 MW of the year 2000) and it will cause a complex of serious technical, economical, ecological, and social consequences. The most important ones for energy sector are the negative power balance and the shortage of power generating capacity which can emerge straight after closure of the second unit of Ignalina NPP. An attempt has been taken to prove, that the most realistic way for replacement of lost power generating capacities is the construction of new nuclear or combined cycle gas turbine power plants. The results of the comparative analysis of their effectiveness and competitiveness are presented in the paper. Estimating the basic prevailing technical and economical factors and three possible scenarios of economy growth, the changes of power balance and levelised cost of produced electricity are compared. It is demonstrated that a new modern nuclear power plant would be competitive and it would be even a more favourable option in respect to a combined cycle gas turbine power plant due to the relatively lower energy production cost, especially when estimating the possible future growth of price for fossil fuel. (authors)

  4. Future energy research in the EU under EIT conditions-pilot projects

    Energy Technology Data Exchange (ETDEWEB)

    Puehringer-Oppermann, Franziska; Bele, Petra; Bussar, Rainer; Stimming, Ulrich [TUM, Dept. of Physics, E19, James-Franck Str. 1, D-85748 Garching (Germany)

    2009-07-01

    The European Institute of Innovation and Technology (EIT) has been established in April 2008. It is an independent organisation with the administrative head in Budapest, a governing board, an executive committee and a chairman. The EIT budget until 2012 is 308 MEUR. EIT will operate through the formation of Knowledge and Innovation Communities (KICs). The first three KICs are foreseen in the areas sustainable energy, ICT and climate mitigation. The European Commission has sponsored four pilot projects (conducted 2008-2009) to help develop a suitable governance structure for cooperations on European scale such as the future KICs. They are Bridge, ComplexEIT, SUCCESS and Gast, dealing with different topics like nanomedicine (Bridge), integration of hardware and software (ComplexEIT), sustainable energy (SUCCESS) and green and safe road transportation (Gast). The strategic objective of these pilot projects is to design, implement and test new models of cooperation in the knowledge triangle. We are involved in SUCCESS and after benchmarking of 66 collaborations in the field sustainable energy, the state of the art of selected representative topics was asessed and shortcomings in governance evaluated by SWOT analysis. In parallel further existing collaborations were used to extract and establish a management structure for such collaborations on the European scale.

  5. Evaluation by fluorescence resonance energy transfer of the stability of nonviral gene delivery vectors under physiological conditions.

    Science.gov (United States)

    Itaka, Keiji; Harada, Atsushi; Nakamura, Kozo; Kawaguchi, Hiroshi; Kataoka, Kazunori

    2002-01-01

    The stability in physiological medium of polyplex- and lipoplex-type nonviral gene vectors was evaluated by detecting the conformational change of complexed plasmid DNA (pDNA) labeled simultaneously with fluorescein (energy donor) and X-rhodamine (energy acceptor) through fluorescence resonance energy transfer (FRET). Upon mixing with cationic components, such as LipofectAMINE, poly(L-lysine), and poly(ethylene glycol)-poly(L-lysine) block copolymer (PEG-PLys), the fluorescence spectrum of doubly labeled pDNA underwent a drastic change due to the occurrence of FRET between the donor-acceptor pair on pDNA taking a globular conformation (condensed state) through complexation. The measurement was carried out also in the presence of 20% serum, under which conditions FRET from condensed pDNA was clearly monitored without interference from coexisting components in the medium, allowing evaluation of the condensed state of pDNA in nonviral gene vectors under physiological conditions. Serum addition immediately induced a sharp decrease in FRET for the LipofectAMINE/pDNA (lipoplex) system, which was consistent with the sharp decrease in the transfection efficiency of the lipoplex system in serum-containing medium. In contrast, the PEG-PLys/pDNA polyplex (polyion complex micelle) system maintained appreciable transfection efficiency even in serum-containing medium, and FRET efficiency remained constant for up to 12 h, indicating the high stability of the polyion complex micelle under physiological conditions.

  6. A thermodynamic approach for selecting operating conditions in the design of reversible solid oxide cell energy systems

    Science.gov (United States)

    Wendel, Christopher H.; Kazempoor, Pejman; Braun, Robert J.

    2016-01-01

    Reversible solid oxide cell (ReSOC) systems are being increasingly considered for electrical energy storage, although much work remains before they can be realized, including cell materials development and system design optimization. These systems store electricity by generating a synthetic fuel in electrolysis mode and subsequently recover electricity by electrochemically oxidizing the stored fuel in fuel cell mode. System thermal management is improved by promoting methane synthesis internal to the ReSOC stack. Within this strategy, the cell-stack operating conditions are highly impactful on system performance and optimizing these parameters to suit both operating modes is critical to achieving high roundtrip efficiency. Preliminary analysis shows the thermoneutral voltage to be a useful parameter for analyzing ReSOC systems and the focus of this study is to quantitatively examine how it is affected by ReSOC operating conditions. The results reveal that the thermoneutral voltage is generally reduced by increased pressure, and reductions in temperature, fuel utilization, and hydrogen-to-carbon ratio. Based on the thermodynamic analysis, many different combinations of these operating conditions are expected to promote efficient energy storage. Pressurized systems can achieve high efficiency at higher temperature and fuel utilization, while non-pressurized systems may require lower stack temperature and suffer from reduced energy density.

  7. Method for Cost-Benefit Analysis of Improved Indoor Climate Conditions and Reduced Energy Consumption in Office Buildings

    Directory of Open Access Journals (Sweden)

    Viktoras Dorosevas

    2013-09-01

    Full Text Available Indoor climate affects health and productivity of the occupants in office buildings, yet in many buildings of this type indoor climate conditions are not well-controlled due to insufficient heating or cooling capacity, high swings of external or internal heat loads, improper control or operation of heating, ventilation and air conditioning (HVAC equipment, etc. However, maintenance of good indoor environmental conditions in buildings requires increased investments and possible higher energy consumption. This paper focuses on the relation between investment costs for retrofitting HVAC equipment as well as decreased energy use and improved performance of occupants in office buildings. The cost-benefit analysis implementation algorithm is presented in this paper, including energy survey of the building, estimation of occupants dissatisfied by key indoor climate indicators using questionnaire survey and measurements. Technique for Order Preference by Similarity to Ideal Solution (TOPSIS analysis is used in the proposed method for data processing. A case study of an office building is presented in order to introduce an application example of the proposed method. Results of the study verify the applicability of the proposed algorithm and TOPSIS analysis as a practical tool for office building surveys in order to maximize productivity by means of cost efficient technical building retrofitting solutions.

  8. Leptin Signaling Is Required for Adaptive Changes in Food Intake, but Not Energy Expenditure, in Response to Different Thermal Conditions

    Science.gov (United States)

    Kaiyala, Karl J.; Ogimoto, Kayoko; Nelson, Jarrell T.; Schwartz, Michael W.; Morton, Gregory J.

    2015-01-01

    Survival of free-living animals depends on the ability to maintain core body temperature in the face of rapid and dramatic changes in their thermal environment. If food intake is not adjusted to meet the changing energy demands associated with changes of ambient temperature, a serious challenge to body energy stores can occur. To more fully understand the coupling of thermoregulation to energy homeostasis in normal animals and to investigate the role of the adipose hormone leptin to this process, comprehensive measures of energy homeostasis and core temperature were obtained in leptin-deficient ob/ob mice and their wild-type (WT) littermate controls when housed under cool (14°C), usual (22°C) or ∼ thermoneutral (30°C) conditions. Our findings extend previous evidence that WT mice robustly defend normothermia in response to either a lowering (14°C) or an increase (30°C) of ambient temperature without changes in body weight or body composition. In contrast, leptin-deficient, ob/ob mice fail to defend normothermia at ambient temperatures lower than thermoneutrality and exhibit marked losses of both body fat and lean mass when exposed to cooler environments (14°C). Our findings further demonstrate a strong inverse relationship between ambient temperature and energy expenditure in WT mice, a relationship that is preserved in ob/ob mice. However, thermal conductance analysis indicates defective heat retention in ob/ob mice, irrespective of temperature. While a negative relationship between ambient temperature and energy intake also exists in WT mice, this relationship is disrupted in ob/ob mice. Thus, to meet the thermoregulatory demands of different ambient temperatures, leptin signaling is required for adaptive changes in both energy intake and thermal conductance. A better understanding of the mechanisms coupling thermoregulation to energy homeostasis may lead to the development of new approaches for the treatment of obesity. PMID:25756181

  9. Research and application of an intelligent control system in central air-conditioning based on energy consumption simulation

    Science.gov (United States)

    Cao, Ling; Che, Wenbin

    2018-05-01

    For the central air-conditioning energy-saving, it is common practice to use a wide range of PTD controllers in engineering to optimize energy savings. However, the shortcomings of the PTD controller have also been magnified on this issue, such as: calculation accuracy is not enough, the calculation time is too long. Particle swarm optimization has the advantage of fast convergence. This paper is based on Particle Swarm Optimization apply in PTD controller tuning parameters in order to achieve the purpose of saving energy while ensuring comfort. The algorithm proposed in this paper can adjust the weight according to the change of population fitness, reduce the weights of particles with lower fitness and enhance the weights of particles with higher fitness in the population, and fully release the population vitality. The method in this paper is validated by the TRNSYS model based on the central air-conditioning system. The experimental results show that the room temperature fluctuation is small, the overshoot is small, the adjustment speed is fast, and the energy-saving fluctuates at 10%.

  10. Energy-efficient strain gauges for the wireless condition monitoring systems in mechanical engineering

    Energy Technology Data Exchange (ETDEWEB)

    Berndt, Michael; Fellner, Thomas; Zeiser, Roderich; Wilde, Juergen [Freiburg Univ. (Germany). Dept. for Microsystems Engineering (IMTEK)

    2012-07-01

    This work focuses on the development of novel strain gauges, which are suited for the operation in autonomous wireless condition monitoring systems. For this purpose, capacitive as well as highly resistive strain gauges were designed and fabricated. The C- and R-sensors were utilised in combination with demonstration circuits, which integrate the circuits for instrumentation, A/D-conversion and furthermore comprise a microcontroller with a wireless transceiver system, all on a small separate printed wiring board. (orig.)

  11. Generating of low energy intensive ion streams in conditions of low pressure

    International Nuclear Information System (INIS)

    Zinoviev, D.V.; Tseluyko, A.F.; Chunadra, A.G.; Yunakov, N.N.

    2000-01-01

    In the work the method of forming of low energy ion streams near the sample surface with separating the generation area of plasma and the acceleration area of ion is offered.It allows to lower pressure in acceleration area essentially (0.01 Pa and below).The separating of the areas takes place at the expense of vacuum resistance in a plasma generating device.The dependence of plasma parameters on exterior parameters of the device is determined and the way of the further decreasing of working pressure in the modification area up to 10 -3 - 10 -4 Pa are shown

  12. Macroscopic mass and energy balance of a pilot plant anaerobic bioreactor operated under thermophilic conditions.

    Science.gov (United States)

    Espinosa-Solares, Teodoro; Bombardiere, John; Chatfield, Mark; Domaschko, Max; Easter, Michael; Stafford, David A; Castillo-Angeles, Saul; Castellanos-Hernandez, Nehemias

    2006-01-01

    Intensive poultry production generates over 100,000 t of litter annually in West Virginia and 9 x 10(6) t nationwide. Current available technological alternatives based on thermophilic anaerobic digestion for residuals treatment are diverse. A modification of the typical continuous stirred tank reactor is a promising process being relatively stable and owing to its capability to manage considerable amounts of residuals at low operational cost. A 40-m3 pilot plant digester was used for performance evaluation considering energy input and methane production. Results suggest some changes to the pilot plant configuration are necessary to reduce power consumption although maximizing biodigester performance.

  13. Trade and agriculture policy conditions for the use of plant oils in the energy field

    International Nuclear Information System (INIS)

    Joerdens, R.

    1994-01-01

    Preservation of resources, ecology and agricultural policy supply the most important argument for an increased use of raw materials which grow again. Regenerative raw materials are at present grown on about 2.5% of the arable land area in Germany, where production for the chemical technical field is to the fore. Access to the energy field is, however, difficult due to the considerable economic deficit compared to fossil fuels. Possibilities of use exist mainly in heating plant and in Diesel engines. (BWI) [de

  14. High energy x-radiographic assessment of conditioned intermediate level waste blocks

    International Nuclear Information System (INIS)

    Lewcock, A.I.; Burch, S.F.; Reynolds, W.N.; Pullen, D.A.W.; Smith, D.

    1985-07-01

    This report describes an effective technique for examining the quality of the solidification matrix material in a 500 litre waste drum, testing for homogeneity and major cracks and the confirmation of set. A high energy x-ray source, (an 8 MeV Linac) and a special x-ray TV system, were used to examine several different types of solidified waste form, with and without background radiation, simulated by the use of an uncollimated radiographic isotope. The system as tested showed no discernable image degradation when the isotope was positioned to give a representative background dose as experienced with active ILW monoliths. (author)

  15. Experimental analysis of energy performance of a ventilated window for heat recovery under controlled conditions

    DEFF Research Database (Denmark)

    Appelfeld, David; Svendsen, Svend

    2011-01-01

    balance of the ventilated window and clarified the methodology for thermal performance evaluation. Comparison between windows with and without ventilation using the window-room-ventilation heat balance revealed that a ventilated window can potentially contribute to energy savings. In addition...... transmittance introduced by the ventilation was higher than the effect of heat recovery. Accordingly, the use of the ventilated windows might be most suitable for window unit with low ventilation rates. The results correlated with theoretical calculations in standards and software. However, the concept...

  16. Simulation of an under-floor heating system integrated with solar energy under the weather conditions of Beirut

    Energy Technology Data Exchange (ETDEWEB)

    Kattan, Patrick; Ghali, Kamel [American University of Beirut (Lebanon)], email: pek01@aub.edu.lb, email: ka04@aub.edu.lb

    2011-07-01

    Residential heating indoors can use convective systems, where hot air is blown into the space, or radiant systems, where a radiant panel transfers heat via both convection and radiation. Radiant systems can provide thermal comfort for less energy by directly heating the human body. The aim of this paper is to assess the feasibility of using under-floor solar energy heating systems in the climatic conditions of Beirut. An under-floor heating system with solar/diesel energy system was developed and optimized specifically for Beirut. Results showed that the system could lead to 38% energy savings and a 96% reduction in CO2 emissions with a solar fraction of 95%. An economic analysis was also performed using incremental prices of diesel costs and the cost of land for the installation; it yielded a figure of 19000$/m2 savings over the system's lifetime. This study demonstrated that the use of an under-floor heating system with solar energy in Beirut would have ecological and economic benefits.

  17. Lymphocytes Mitochondrial Physiology as Biomarker of Energy Metabolism during Fasted and Fed Conditions

    Directory of Open Access Journals (Sweden)

    Erika Cortez

    2012-01-01

    Full Text Available Mitochondria are central coordinators of energy metabolism, and changes of their physiology have long been associated with metabolic disorders. Thus, observations of energy dynamics in different cell types are of utmost importance. Therefore, tools with quick and easy handling are needed for consistent evaluations of such interventions. In this paper, our main hypothesis is that during different nutritional situations lymphocytes mitochondrial physiology could be associated with the metabolism of other cell types, such as cardiomyocytes, and consequently be used as metabolic biomarker. Blood lymphocytes and heart muscle fibers were obtained from both fed and 24 h-fasted mice, and mitochondrial analysis was assessed by high-resolution respirometry and western blotting. Carbohydrate-linked oxidation and fatty acid oxidation were significantly higher after fasting. Carnitine palmitoil transferase 1 and uncouple protein 2 contents were increased in the fasted group, while the glucose transporters 1 and 4 and the ratio phosphorylated AMP-activated protein kinase/AMPK did not change between groups. In summary, under a nutritional status modification, mitochondria demonstrated earlier adaptive capacity than other metabolic sensors such as glucose transporters and AMPK, suggesting the accuracy of mitochondria physiology of lymphocytes as biomarker for metabolic changes.

  18. Studies of nuclear matter under extreme conditions: Heavy-ion interactions at ultra-relativistic energies

    Energy Technology Data Exchange (ETDEWEB)

    Nystrand, J

    1996-10-01

    The charged particle production in ultra-relativistic nucleus-nucleus collisions in the energy range 4-200 A GeV has been studied. Two different experimental techniques have been utilized: nuclear emulsions and multi-step avalanche chambers. The performance of the chambers in the experiment as well as the analysis of the chamber data are described in the thesis. The reconstructed particle momenta have been used to study transverse momentum distribution of negatively charged particles, and to perform intensity interferometry analyses in order to determine the source size and study the time-evolution of the interactions. Multiplicity and pseudorapidity distributions of singly charged particles obtained from interactions in nuclear emulsion have been studied. Simulations have been performed with various Monte-Carlo models, and particularly the effects of the hadronic rescattering have been studied. The results of the analysis have illustrated the great importance of the nuclear geometry in ultra-relativistic nucleus-nucleus collisions. Based on gaussian parametrizations a method of predicting the pseudorapidity distributions in systems of different sizes and at different energies has been developed. Furthermore, the multiplicity and angular distributions of slow, target associated particles have been analyzed. 99 refs, 19 figs.

  19. Studies of nuclear matter under extreme conditions: Heavy-ion interactions at ultra-relativistic energies

    International Nuclear Information System (INIS)

    Nystrand, J.

    1996-10-01

    The charged particle production in ultra-relativistic nucleus-nucleus collisions in the energy range 4-200 A GeV has been studied. Two different experimental techniques have been utilized: nuclear emulsions and multi-step avalanche chambers. The performance of the chambers in the experiment as well as the analysis of the chamber data are described in the thesis. The reconstructed particle momenta have been used to study transverse momentum distribution of negatively charged particles, and to perform intensity interferometry analyses in order to determine the source size and study the time-evolution of the interactions. Multiplicity and pseudorapidity distributions of singly charged particles obtained from interactions in nuclear emulsion have been studied. Simulations have been performed with various Monte-Carlo models, and particularly the effects of the hadronic rescattering have been studied. The results of the analysis have illustrated the great importance of the nuclear geometry in ultra-relativistic nucleus-nucleus collisions. Based on gaussian parametrizations a method of predicting the pseudorapidity distributions in systems of different sizes and at different energies has been developed. Furthermore, the multiplicity and angular distributions of slow, target associated particles have been analyzed. 99 refs, 19 figs

  20. Conditions for energy generation as an alternative approach to compost utilization.

    Science.gov (United States)

    Raclavska, H; Juchelkova, D; Skrobankova, H; Wiltowski, T; Campen, A

    2011-01-01

    Very strict limits constrain the current possibilities for compost utilization in agriculture and for land reclamation, thus creating a need for other compost utilization practices. A favourable alternative can be compost utilization as a renewable heat source - alternative fuel. The changes of the basic physical-chemical parameters during the composting process are evaluated. During the composting process, energy losses of 920 kJ/kg occur, caused by carbohydrate decomposition (loss of 12.64% TOC). The net calorific value for mature compost was 11.169 kJ/kg dry matter. The grain size of compost below 0.045 mm has the highest ash content. The energetic utilization of compost depended on moisture, which can be influenced by paper addition or by prolonging the time of maturation to six months.

  1. Theoretical ion implantation profiles for low energy protons under channeling conditions

    International Nuclear Information System (INIS)

    Nobel, J.A.; Sabin, J.R.; Trickey, S.B.

    1994-01-01

    The authors present early results from the CHANNEL code, which simulates the passage of ionized projectiles through bulk solids. CHANNEL solves the classical equations of motion for the projectile using a force obtained from the gradient of the quantum mechanically derived coulombic potential of the solid (determined via a full potential augmented plane wave (FLAPW) calculation on the bulk) and a quantum mechanical energy dissipation term, the stopping power, as determined from the method of Echenique, Neiminen, and Ritchie. The code then generates the trajectory of the ionic projectile for a given incident position on the unit cell face and an initial velocity. The authors use CHANNEL to generate an ion (proton) implantation profile for the test case of simple cubic hydrogen with the projectile's initial velocity parallel to the (100) channel. Further preliminary results for ion implantation profiles of protons in diamond structure Si, with initial velocity along the (100) and (110) channels, are given

  2. Energies and media nr 33. Niger. Conditions for the nuclear sector. Waste disposal

    International Nuclear Information System (INIS)

    2010-11-01

    After having evoked the situation of ARLIT's employees who are held as hostages in Niger, and some comments on recent events in the nuclear sector in different countries (energy policy and projects in India, in China, in the USA with opportunities for the French nuclear industry, and in Germany, Belgium, France), this publication discusses the issue of nuclear waste disposal. After having briefly recalled the content of the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management, it discusses the option of waste storage in deep geological formation, an option which has been chosen by several countries. It questions whether sea beds will ever be a storage option. It comments the case of Germany, of the United States where the storage of high level and long-lived wastes is still facing major problems

  3. Renewable energy production support schemes for residential-scale solar photovoltaic systems in Nordic conditions

    International Nuclear Information System (INIS)

    Hirvonen, Janne; Kayo, Genku; Cao, Sunliang; Hasan, Ala; Sirén, Kai

    2015-01-01

    The objective of this study was to examine the effect of production-based support schemes on the economic feasibility of residential-scale PV systems (1–10 kW) in Finland. This was done by calculating the payback time for various sizes of newly installed PV systems for a Finnish detached house with district heating. Three types of economic support schemes (guaranteed selling price, fixed premiums and self-consumption incentives) were tested in an hourly simulation. The load of the building was based on real-life measurements, while PV output was simulated with TRNSYS software. The energy results were post-processed with economic data in MATLAB to find the payback time. Hourly electricity prices from the Nordic energy market were used with PV system prices from Finnish companies. Unsubsidised residential PV systems in Finland had payback times of more than 40 years. The production-based support for PV generation needs to be two to three times the buying price of electricity, to make it possible to pay back the initial investment in 20 years. Low capacity systems with more than 50% self-consumption (under 3 kW) were favoured by self-consumption incentives, while high capacity systems with less than 40% self-consumption (over 5 kW) were favoured by the FIT-type support schemes. - Highlights: • Unsubsidised residential PV is uneconomical in Finland. • Support rate must be 2 times the electricity price for reasonable payback time. • Even using all electricity on-site is not profitable enough without support. • Assumed real interest rate had great influence on payback time. • Hourly electricity prices are much lower than average values from Finnish statistics

  4. Solar cooling between thermal and photovoltaic: An energy and economic comparative study in the Mediterranean conditions

    International Nuclear Information System (INIS)

    Noro, M.; Lazzarin, R.M.

    2014-01-01

    This paper considers different cooling systems and investigates the most promising alternatives when solar energy is to be used to supply the cooling demand. All the systems are evaluated during a summer cooling season by the energetic and economic point of view by dynamic simulation for two different climates. For Milan (Cfb climate) the highest OSE (overall system efficiency) is reached by LiBr (lithium-bromide) double effect absorption chiller driven by parabolic through collector (0.53). In terms of the collecting surface area, the best systems for Milan feature 0.08 m 2  MJ −1 per day both for electric system (mono-crystalline photovoltaic coupled to water cooled chiller) and thermal system (PTC (parabolic trough collectors) coupled to double effect water-LiBr absorption chiller). Southern latitudes like Trapani (Csa climate) allow a quite better performance for thermal solar cooling solutions. The NPV (net present worths) of electric solar cooling solutions are favorable with respect to the traditional solution and the DPV (discounted payback periods) are all lower than the period of economic analysis above all for water cooled chillers. Finally a sensitivity analysis of the specific investment cost (€ MJ −1 per day) is carried out regarding the investment cost of collectors, the solar ratio and the interest rate. - Highlights: • Solar cooling is obtained with solar thermal or PV (photovoltaic) with easy available equipment. • In the past PV driven systems for solar cooling were not considered as too expensive. • An energy/economic comparison is carried out for the various solar cooling systems. • Sensitivity analyses are carried out varying different parameters

  5. Pot plant production, environmental conditions and energy consumption in insulated greenhouses

    Energy Technology Data Exchange (ETDEWEB)

    Bjerre, H.; Amsen, M.G. (Statens Planteavlsforsoeg, Havebrugscentret, Institut for Vaeksthuskulturer, Aarslev, Denmark)

    1984-01-01

    An energy experiment with 4 different types of greenhouses was carried out in the winter 1980-81 and 1981-82. Three of these greenhouses were insulated. The reference house was a single layer glasshouse with a mobile shading curtain, which was drawn at night. A comparison with the reference house showed the following energy savings for the insulated houses: Double glass 29-32%, double acryllic 39%, and thermal screens 22-24%. On average the air humidity was 80-86% RH in the double acryllic greenhouse and in the double glass house, whereas the levels was 5-10% lower in the 2 greenhouses with single glass. In spite of the high air humidity in the permanently insulated houses, no plant diseases occurred. The dry matter production of seven plant species was recorded in all greenhouses on the same date. Compared with the reference house 3 of the plant species showed a 5-10% higher production in the double acryllic greenhouse as well as the house with thermal screens. The remaining 4 plant species did not show any differences, between the 3 greenhouses. In the double glass house the production was considerably lower. To study the growth in detail, Tagetes plants were grown for 3-week periods during the winter in all houses. The aim of this study was to investigate whether the ratio between the growth in the 4 greenhouses was the same when periods of high light intensity were compared to periods with low light intensity. No characteristic changes with increasing light intensities could be observed between the different greenhouses. The differences between the greenhouses in time of production for the pot plants were generally small. The most remarkable difference in plant quality between the houses could be seen with Chrysanthemum and Kalanchoe. These 2 plant species were considerably less compact in the double acryllic greenhouse. Chrysanthemum was also less compact in the double glass house.

  6. Exergy and energy analyses of two different types of PCM based thermal management systems for space air conditioning applications

    International Nuclear Information System (INIS)

    Tyagi, V.V.; Pandey, A.K.; Buddhi, D.; Tyagi, S.K.

    2013-01-01

    Highlights: ► Calcium chloride hexahydrate (CaCl 2 ⋅6H 2 O) as a PCM was used in this study. ► Two different capsulated system (HDPE based panel and balls) were designed. ► The results of CaCl 2 ⋅6H 2 O are very attractive for space air conditioning. ► Energy and exergy analyses for space cooling applications. - Abstract: This communication presents the experimental study of PCM based thermal management systems for space heating and cooling applications using energy and exergy analysis. Two different types of based thermal management system (TMS-I and TMS-II) using calcium chloride hexahydrate as the heat carrier has been designed, fabricated and studied for space heating and cooling applications at a typical climatic zone in India. In the first experimental arrangement the charging of PCM has been carried out with air conditioning system while discharging has been carried out using electric heater for both the thermal management systems. While in the second arrangement the charging of PCM has been carried out by solar energy and the discharging has been carried out by circulating the cooler ambient air during the night time. In the first experiment, TMS-I is found to be more effective than that of TMS-II while it was found to be reverse in the case of second experiment for both the charging and discharging processes not only for energetic but also for the exergetic performances

  7. Energy problems of the central systems of air conditioning; Problemas energeticos de los sistemas centrales de climatizacion

    Energy Technology Data Exchange (ETDEWEB)

    Cardero Corria, Gaspar [Cubanacan, S.A., Varadero (Cuba)

    2003-07-01

    The central systems of air conditioning are widely used in air conditioning production for several reasons among which excel: 1) Better aesthetic of the building, 2) Less noise in the air conditioning premises and 3) Greater yield of the consumed energy. This is indeed the third reason in which this paper will try to contribute with elements that will allow reveal the problem and to identify some possible causes that originate it. The centralized systems of air conditioning must produce conditioned air with lesser power cost than the individual systems, it is that saving which allows to recover an investment that normally surpasses them in 3 to 5 times. Nevertheless, the real numbers do not demonstrate that. [Spanish] Los sistemas centrales de climatizacion son ampliamente usados en la produccion de aire acondicionado por varias razones entre las que sobresalen: 1) Mejor estetica del edificio, 2) Menor ruido en los locales climatizados y 3) Mayor rendimiento de la energia consumida. Es precisamente la tercera razon en la cual este trabajo intentara aportar elementos que permitan develar el problema e identificar algunas posibles causas que lo originan. Los sistemas centralizados de climatizacion deben producir aire acondicionado con un menor gasto energetico que los sistemas individuales, es precisamente ese ahorro lo que permite recuperar una inversion que normalmente los supera en 3 a 5 veces. Sin embargo, los numeros reales no demuestran eso.

  8. Determination of maximum power transfer conditions of bimorph piezoelectric energy harvesters

    KAUST Repository

    Ahmad, Mahmoud Al

    2012-07-23

    In this paper, a method to find the maximum power transfer conditions in bimorph piezoelectric-based harvesters is proposed. Explicitly, we derive a closed form expression that relates the load resistance to the mechanical parameters describing the bimorph based on the electromechanical, single degree of freedom, analogy. Further, by taking into account the intrinsic capacitance of the piezoelectric harvester, a more descriptive expression of the resonant frequency in piezoelectric bimorphs was derived. In interest of impartiality, we apply the proposed philosophy on previously published experimental results and compare it with other reported hypotheses. It was found that the proposed method was able to predict the actual optimum load resistance more accurately than other methods reported in the literature. © 2012 American Institute of Physics.

  9. Mid-IR Imaging of Orion BN/KL: Modeling of Physical Conditions and Energy Balance

    Science.gov (United States)

    Gezari, Daniel; Varosi, Frank; Dwek, Eli; Danchi, William C.; Tan, Jonathan; Okumura, Shin-ichiro

    2016-01-01

    We have modeled two mid-infrared imaging photometry data sets to determine the spatial distribution of physical conditions in the BN/KL (Becklin-Neugebauer / Kleinmann-Low) infrared complex. We observed the BN/KL region using the 10-meter Keck I telescope and the LWS (Living With a Star) in the direct imaging mode, over a 13 inch by 19 inch field . We also modeled images obtained with COMICS (Cooled Mid-Infrared Camera and Spectrometer, Kataza et al. 2000) at the 8.2-meter SUBARU telescope, over a total field of view [which] is 31 inches by 41 inches in a total of nine bands: 7.8, 8.8, 9.7, 10.5, 11.7, 12.4, 18.5, 20.8 and 24.8 microns with 1-micron bandwidth interference filters.

  10. LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery

    Science.gov (United States)

    Ko, Suk M.

    1980-01-01

    This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

  11. System and method of providing quick thermal comfort with reduced energy by using directed spot conditioning

    Science.gov (United States)

    Wang, Mingyu; Kadle, Prasad S.; Ghosh, Debashis; Zima, Mark J.; Wolfe, IV, Edward; Craig, Timothy D

    2016-10-04

    A heating, ventilation, and air conditioning (HVAC) system and a method of controlling a HVAC system that is configured to provide a perceived comfortable ambient environment to an occupant seated in a vehicle cabin. The system includes a nozzle configured to direct an air stream from the HVAC system to the location of a thermally sensitive portion of the body of the occupant. The system also includes a controller configured to determine an air stream temperature and an air stream flow rate necessary to establish the desired heat supply rate for the sensitive portion and provide a comfortable thermal environment by thermally isolating the occupant from the ambient vehicle cabin temperature. The system may include a sensor to determine the location of the sensitive portion. The nozzle may include a thermoelectric device to heat or cool the air stream.

  12. Effect of fee-for-service air-conditioning management in balancing thermal comfort and energy usage.

    Science.gov (United States)

    Chen, Chen-Peng; Hwang, Ruey-Lung; Shih, Wen-Mei

    2014-11-01

    Balancing thermal comfort with the requirement of energy conservation presents a challenge in hot and humid areas where air-conditioning (AC) is frequently used in cooling indoor air. A field survey was conducted in Taiwan to demonstrate the adaptive behaviors of occupants in relation to the use of fans and AC in a school building employing mixed-mode ventilation where AC use was managed under a fee-for-service mechanism. The patterns of using windows, fans, and AC as well as the perceptions of students toward the thermal environment were examined. The results of thermal perception evaluation in relation to the indoor thermal conditions were compared to the levels of thermal comfort predicted by the adaptive models described in the American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 55 and EN 15251 and to that of a local model for evaluating thermal adaption in naturally ventilated buildings. A thermal comfort-driven adaptive behavior model was established to illustrate the probability of fans/AC use at specific temperature and compared to the temperature threshold approach to illustrate the potential energy saving the fee-for-service mechanism provided. The findings of this study may be applied as a reference for regulating the operation of AC in school buildings of subtropical regions.

  13. An energy-saving set-point optimizer with a sliding mode controller for automotive air-conditioning/refrigeration systems

    International Nuclear Information System (INIS)

    Huang, Yanjun; Khajepour, Amir; Ding, Haitao; Bagheri, Farshid; Bahrami, Majid

    2017-01-01

    Highlights: • A novel two-layer energy-saving controller for automotive A/C-R system is developed. • A set-point optimizer at the outer loop is designed based on the steady state model. • A sliding mode controller in the inner loop is built. • Extensively experiments studies show that about 9% energy can be saving by this controller. - Abstract: This paper presents an energy-saving controller for automotive air-conditioning/refrigeration (A/C-R) systems. With their extensive application in homes, industry, and vehicles, A/C-R systems are consuming considerable amounts of energy. The proposed controller consists of two different time-scale layers. The outer or the slow time-scale layer called a set-point optimizer is used to find the set points related to energy efficiency by using the steady state model; whereas, the inner or the fast time-scale layer is used to track the obtained set points. In the inner loop, thanks to its robustness, a sliding mode controller (SMC) is utilized to track the set point of the cargo temperature. The currently used on/off controller is presented and employed as a basis for comparison to the proposed controller. More importantly, the real experimental results under several disturbed scenarios are analysed to demonstrate how the proposed controller can improve performance while reducing the energy consumption by 9% comparing with the on/off controller. The controller is suitable for any type of A/C-R system even though it is applied to an automotive A/C-R system in this paper.

  14. Tightness and suitability evaluation of abandoned salt caverns served as hydrocarbon energies storage under adverse geological conditions (AGC)

    International Nuclear Information System (INIS)

    Wei, Liu; Jie, Chen; Deyi, Jiang; Xilin, Shi; Yinping, Li; Daemen, J.J.K.; Chunhe, Yang

    2016-01-01

    Highlights: • Tightness conditions are set to assess use of old caverns for hydrocarbons storage. • Gas seepage and tightness around caverns are numerically simulated under AGC. • κ of interlayers act as a key factor to affect the tightness and use of salt cavern. • The threshold upper permeability of interlayers is proposed for storing oil and gas. • Three types of real application are introduced by using the tightness conditions. - Abstract: In China, the storage of hydrocarbon energies is extremely insufficient partially due to the lack of storage space, but on the other side the existence of a large number of abandoned salt caverns poses a serious threat to safety and geological environments. Some of these caverns, defined as abandoned caverns under adverse geological conditions (AGC), are expected to store hydrocarbon energies (natural gas or crude oil) to reduce the risk of potential disasters and simultaneously support the national strategic energy reserve of China. Herein, a series of investigations primarily related to the tightness and suitability of the caverns under AGC is performed. Laboratory measurements to determine the physical and mechanical properties as well as porosity and permeability of bedded salt cores from a near target cavern are implemented to determine the petro-mechanical properties and basic parameters for further study. The results show that the mechanical properties of the bedded rock salts are satisfactory for the stability of caverns. The interface between the salt and interlayers exhibits mechanical properties that are between those of rock salt and interlayers and in particular is not a weak zone. The silty mudstone interlayers have relatively high porosity and permeability, likely due to their low content of clay minerals and the presence of halite-filled cracks. The conditions for evaluating the tightness and suitability of a cavern for storing hydrocarbons are proposed, including “No tensile stress,”

  15. Modal analysis of main steam line piping under high energy line break condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae-Jin; Kim, Seung Hyun; Je, Sang-Yun; Chang, Yoon-Suk [Kyung Hee University, Yongin (Korea, Republic of)

    2016-10-15

    If HELB (High Energy Line Break) occurs in NPPs (Nuclear Power Plants), not only environmental effect like release of radioactive material but also secondary structural defects should be considered. Jet impingement phenomenon caused by sudden pipe rupture may lead to severe damage on neighboring safe-related components and other structure. Lots of studies have been conducted to assess dynamic behaviors of the SG and MSL piping while pipe whip restraints and jet impingement shields are taken into account during design stage. Arroyo et al. performed modal analyses of a simple square component to examine the jet impingement phenomenon. Also, structural characteristics were predicted to assure structural integrity against the HELB. In this study, we examined dynamic characteristics of SG and MSL piping in a typical 1000MWe NPP. Simulation was performed by using two commercial computational softwares. In particular, modal analyses were conducted to determine mode shapes and natural frequencies of the structure and maximum displacements. The data obtain from each software were compared and observation was discussed in relation to the jet impingement phenomenon. In this research, modal analyses on the SG and MSL piping were carried out to get natural frequencies, vibration mode shapes and maximum displacements. Thereby, the following key finding was observed. (1) Maximum displacement was calculated at the top of SG outlet nozzle with y-directional bending at the third mode. (2) The differences between two models were respectively 7% in natural frequencies and less than 1% in maximum displacements.

  16. Conditions for order and chaos in the dynamics of a trapped Bose-Einstein condensate in coordinate and energy space

    Science.gov (United States)

    Sakhel, Roger R.; Sakhel, Asaad R.; Ghassib, Humam B.; Balaz, Antun

    2016-03-01

    We investigate numerically conditions for order and chaos in the dynamics of an interacting Bose-Einstein condensate (BEC) confined by an external trap cut off by a hard-wall box potential. The BEC is stirred by a laser to induce excitations manifesting as irregular spatial and energy oscillations of the trapped cloud. Adding laser stirring to the external trap results in an effective time-varying trapping frequency in connection with the dynamically changing combined external+laser potential trap. The resulting dynamics are analyzed by plotting their trajectories in coordinate phase space and in energy space. The Lyapunov exponents are computed to confirm the existence of chaos in the latter space. Quantum effects and trap anharmonicity are demonstrated to generate chaos in energy space, thus confirming its presence and implicating either quantum effects or trap anharmonicity as its generator. The presence of chaos in energy space does not necessarily translate into chaos in coordinate space. In general, a dynamic trapping frequency is found to promote chaos in a trapped BEC. An apparent means to suppress chaos in a trapped BEC is achieved by increasing the characteristic scale of the external trap with respect to the condensate size.

  17. Photodouble ionization studies of the Ne(2s{sup 2}) state under unequal energy sharing conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, P [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo, Rome (Italy); Kheifets, A [Research School of Physical Sciences and Engineering, Australian National University, Canberra (Australia); Otranto, S [Physics Department, University of Missouri-Rolla, Rolla MO (United States); CONICET and Depto. de Fisica, Universidad Nacional del Sur, 8000 Bahia Blanca (Argentina); Coreno, M [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo, Rome (Italy); CNR-TASC, Gas Phase Photoemission Beamline at Elettra, Area Science Park, Trieste (Italy); Feyer, V [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo, Rome (Italy); Institute of Electron Physics, National Academy of Sciences, Uzhgorod (Ukraine); Colavecchia, F D [CONICET and Centro Atomico Bariloche, 8400 SC de Bariloche (Argentina); Garibotti, C R [CONICET and Centro Atomico Bariloche, 8400 SC de Bariloche (Argentina); Avaldi, L [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo, Rome (Italy); CNR-TASC, Gas Phase Photoemission Beamline at Elettra, Area Science Park, Trieste (Italy)

    2006-04-28

    The triple differential cross section (TDCS) of the He{sup 2+}(1s{sup -2}) and Ne{sup 2+}(2s{sup -2}) states has been studied under unequal energy sharing conditions and perpendicular geometry, for a ratio of about 3 between the energies of the two ejected electrons. The dynamical quantities which govern the photodouble ionization (PDI) process, i.e. the squared moduli of the gerade and ungerade complex amplitudes and the cosine of their relative phase, have been extracted from the experimental data. The results from the two targets have been compared between themselves as well as with the theoretical predictions of the SC3 and convergent close coupling (CCC) calculations. This work represents a joint experimental and theoretical approach to the investigation of PDI of atomic systems with more than two electrons.

  18. Energy-Efficiency Analysis of a Distributed Queuing Medium Access Control Protocol for Biomedical Wireless Sensor Networks in Saturation Conditions

    Directory of Open Access Journals (Sweden)

    Christos Verikoukis

    2011-01-01

    Full Text Available The aging population and the high quality of life expectations in our society lead to the need of more efficient and affordable healthcare solutions. For this reason, this paper aims for the optimization of Medium Access Control (MAC protocols for biomedical wireless sensor networks or wireless Body Sensor Networks (BSNs. The hereby presented schemes always have in mind the efficient management of channel resources and the overall minimization of sensors’ energy consumption in order to prolong sensors’ battery life. The fact that the IEEE 802.15.4 MAC does not fully satisfy BSN requirements highlights the need for the design of new scalable MAC solutions, which guarantee low-power consumption to the maximum number of body sensors in high density areas (i.e., in saturation conditions. In order to emphasize IEEE 802.15.4 MAC limitations, this article presents a detailed overview of this de facto standard for Wireless Sensor Networks (WSNs, which serves as a link for the introduction and initial description of our here proposed Distributed Queuing (DQ MAC protocol for BSN scenarios. Within this framework, an extensive DQ MAC energy-consumption analysis in saturation conditions is presented to be able to evaluate its performance in relation to IEEE 802.5.4 MAC in highly dense BSNs. The obtained results show that the proposed scheme outperforms IEEE 802.15.4 MAC in average energy consumption per information bit, thus providing a better overall performance that scales appropriately to BSNs under high traffic conditions. These benefits are obtained by eliminating back-off periods and collisions in data packet transmissions, while minimizing the control overhead.

  19. Incorporating fan control into air-conditioning systems to improve energy efficiency and transient response

    International Nuclear Information System (INIS)

    Yeh, T.-J.; Chen, Yun-Jih; Hwang, Wei-Yang; Lin, Jin-Long

    2009-01-01

    Modern air-conditioners frequently incorporate variable-speed compressors and variable-opening expansion valves with feedback control to improve performance and power efficiency. Because making the fan speeds adjustable adds flexibility to the control design and thus can lead to further improvements in performance and efficiency, this paper proposes two control algorithms, respectively, incorporating the outdoor fan and the indoor fan as the additional control inputs for air-conditioning systems. Both of the control algorithms are designed based on a low-order, linear model obtained from system identification. The first algorithm, which modulates the outdoor fan speed, can reduce the steady state power consumption if the temperature difference between the condenser and the outdoor environment is controlled properly. The second algorithm, which adds one more degree of freedom to control by modulating the indoor fan speed, can improve the transient response because actuator saturations become less likely to occur. The two control algorithms are implemented on a split-type residential air-conditioner and their respective performance is validated experimentally.

  20. Modeling and optimization of energy generation and storage systems for thermal conditioning of buildings targeting conceptual building design

    Energy Technology Data Exchange (ETDEWEB)

    Grahovac, Milica

    2012-11-29

    The thermal conditioning systems are responsible for almost half of the energy consump-tion by commercial buildings. In many European countries and in the USA, buildings account for around 40% of primary energy consumption and it is therefore vital to explore further ways to reduce the HVAC (Heating, Ventilation and Air Conditioning) system energy consumption. This thesis investigates the relationship between the energy genera-tion and storage systems for thermal conditioning of buildings (shorter: primary HVAC systems) and the conceptual building design. Certain building design decisions irreversibly influence a building's energy performance and, conversely, many generation and storage components impose restrictions on building design and, by their nature, cannot be introduced at a later design stage. The objective is, firstly, to develop a method to quantify this influence, in terms of primary HVAC system dimensions, its cost, emissions and energy consumption and, secondly, to enable the use of the developed method by architects during the conceptual design. In order to account for the non-stationary effects of the intermittent renewable energy sources (RES), thermal storage and for the component part load efficiencies, a time domain system simulation is required. An abstract system simulation method is proposed based on seven pre-configured primary HVAC system models, including components such as boil-ers, chillers and cooling towers, thermal storage, solar thermal collectors, and photovoltaic modules. A control strategy is developed for each of the models and their annual quasi-stationary simulation is performed. The performance profiles obtained are then used to calculate the energy consumption, carbon emissions and costs. The annuity method has been employed to calculate the cost. Optimization is used to automatically size the HVAC systems, based on their simulation performance. Its purpose is to identify the system component dimensions that provide

  1. Modeling and optimization of energy generation and storage systems for thermal conditioning of buildings targeting conceptual building design

    Energy Technology Data Exchange (ETDEWEB)

    Grahovac, Milica

    2012-11-29

    The thermal conditioning systems are responsible for almost half of the energy consump-tion by commercial buildings. In many European countries and in the USA, buildings account for around 40% of primary energy consumption and it is therefore vital to explore further ways to reduce the HVAC (Heating, Ventilation and Air Conditioning) system energy consumption. This thesis investigates the relationship between the energy genera-tion and storage systems for thermal conditioning of buildings (shorter: primary HVAC systems) and the conceptual building design. Certain building design decisions irreversibly influence a building's energy performance and, conversely, many generation and storage components impose restrictions on building design and, by their nature, cannot be introduced at a later design stage. The objective is, firstly, to develop a method to quantify this influence, in terms of primary HVAC system dimensions, its cost, emissions and energy consumption and, secondly, to enable the use of the developed method by architects during the conceptual design. In order to account for the non-stationary effects of the intermittent renewable energy sources (RES), thermal storage and for the component part load efficiencies, a time domain system simulation is required. An abstract system simulation method is proposed based on seven pre-configured primary HVAC system models, including components such as boil-ers, chillers and cooling towers, thermal storage, solar thermal collectors, and photovoltaic modules. A control strategy is developed for each of the models and their annual quasi-stationary simulation is performed. The performance profiles obtained are then used to calculate the energy consumption, carbon emissions and costs. The annuity method has been employed to calculate the cost. Optimization is used to automatically size the HVAC systems, based on their simulation performance. Its purpose is to identify the system component dimensions that provide minimal

  2. Simulation of the steady-state energy transfer in rigid bodies, with convective-radiative boundary conditions, employing a minimum principle

    International Nuclear Information System (INIS)

    Gama, R.M.S. da.

    1992-08-01

    The energy transfer phenomenon in a rigid and opaque body that exchanges energy, with the environment, by convection and by diffuse thermal radiation is studied. The considered phenomenon is described by a partial differential equation, subjected to (nonlinear) boundary conditions. A minimum principle, suitable for a large class of energy transfer problems is presented. Some particular cases are simulated. (author)

  3. Structural Analysis of Shipping Casks, Vol. 9. Energy Absorption Capabilities of Plastically Deformed Struts Under Specified Impact Loading Conditions (Thesis)

    International Nuclear Information System (INIS)

    Davis, F.C.

    2001-01-01

    The purpose of this investigation was to determine the energy absorption characteristics of plastically deformed inclined struts under impact loading. This information is needed to provide a usable method by which designers and analysts of shipping casks for radioactive or fissile materials can determine the energy absorption capabilities of external longitudinal fins on cylindrical casks under specified impact conditions. A survey of technical literature related to experimental determination of the dynamic plastic behavior of struts revealed no information directly applicable to the immediate problem, especially in the impact velocity ranges desired, and an experimental program was conducted to obtain the needed data. Mild-steel struts with rectangular cross sections were impacted by free-falling weights dropped from known heights. These struts or fin specimens were inclined at five different angles to simulate different angles of impact that fins on a shipping cask could experience under certain accident conditions. The resisting force of the deforming strut was measured and recorded as a function of time by using load cells instrumented with resistance strain gage bridges, signal conditioning equipment, an oscilloscope, and a Polaroid camera. The acceleration of the impacting weight was measured and recorded as a function of time during the latter portion of the testing program by using an accelerometer attached to the drop hammer, appropriate signal conditioning equipment, the oscilloscope, and the camera. A digital computer program was prepared to numerically integrate the force-time and acceleration-time data recorded during the tests to obtain deformation-time data. The force-displacement relationships were then integrated to obtain values of absorbed energy with respect to deformation or time. The results for various fin specimen geometries and impact angles are presented graphically, and these curves may be used to compute the energy absorption capacity of

  4. Energy conservation with semi-controlled areas by air conditioning in nursery schools. The nursery school Dragvoll

    Energy Technology Data Exchange (ETDEWEB)

    Brattset, O; Hestnes, A G

    1985-02-01

    Dragvoll nursery school in Trondheim (Norway) is designed with a central winter garden built up by glazed walls and a glass roof, and surrounded by classrooms. The ventilating air is preheated in a heat exchanger, and then postheated in the said garden by the solar flux before entering the air conditioning system. A comparative evaluation of the energy consumption with the total floor area of about 57 m/sup 2/ is done in relation to a conventionally built nursery school with a floor area of about 520 m/sup 2/. The saving potential is found to 52%. 9 drawing.

  5. Energy and Emission Characteristics of a Short-Arc Xenon Flash Lamp Under "Saturated" Optical Brightness Conditions

    Science.gov (United States)

    Kamrukov, A. S.; Kireev, S. G.; Kozlov, N. P.; Shashkovskii, S. G.

    2017-09-01

    We present the results of a study of the electrical, energy, and spectral brightness characteristics of an experimental three-electrode high-pressure xenon flash lamp under conditions ensuring close to maximum possible spectral brightness for the xenon emission. We show that under saturated optical brightness conditions (brightness temperature in the visible region of the spectrum 30,000 K), emission of a pulsed discharge in xenon is quite different from the emission from an ideal blackbody: the maximum brightness temperatures are 24,000 K in the short-wavelength UV region and 19,000 K in the near IR range. The relative fraction of UV radiation in the emission spectrum of the lamp is >50%, which lets us consider such lamps as promising broadband sources of radiation with high spectral brightness for many important practical applications.

  6. Impact of Ambient Conditions of Arab Gulf Countries on the Performance of Gas Turbines Using Energy and Exergy Analysis

    Directory of Open Access Journals (Sweden)

    Saleh S. Baakeem

    2017-01-01

    Full Text Available In this paper, energy and exergy analysis of typical gas turbines is performed using average hourly temperature and relative humidity for selected Gulf cities located in Saudi Arabia, Kuwait, United Arab Emirates, Oman, Bahrain and Qatar. A typical gas turbine unit of 42 MW is considered in this study. The electricity production, thermal efficiency, fuel consumption differences between the ISO conditions and actual conditions are determined for each city. The exergy efficiency and exergy destruction rates for the gas turbine unit and its components are also evaluated taking ISO conditions as reference conditions. The results indicate that the electricity production losses occur in all cities during the year, except in Dammam and Kuwait for the period between November and March. During a typical day, the variation of the power production can reach 4 MW. The rate of exergy destruction under the combined effect of temperature and humidity is significant in hot months reaching a maximum of 12 MW in July. The presented results show also that adding inlet cooling systems to the existing gas turbine units could be justified in hot periods. Other aspects, such as the economic and environmental ones, should also be investigated.

  7. Development and analysis of an economizer control strategy algorithm to promote an opportunity for energy savings in air conditioning installations

    Energy Technology Data Exchange (ETDEWEB)

    Neto, Jose H.M.; Azevedo, Walter L. [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET), Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica]. E-mail: henrique@daem.des.cefetmg.br

    2000-07-01

    This work presents an algorithm control strategy denominated enthalpy economizer. The objective of this algorithm strategy is to determine the adequate fractions of outside and return air flowrates entering a cooling coil based on the analysis of the outside, return and supply air enthalpies, rather than on the analysis of the dry bulb temperatures. The proposed algorithm predicts the actual opening position of the outside and return air dampers in order to provide the lower mixing air enthalpy. First, the psychometrics properties of the outside and return air are calculated from actual measurements of the dry and wet bulb temperatures. Then, three distinct cases are analyzed: the enthalpy of the outside air is lower than the enthalpy of the supply air (free cooling); the enthalpy of the outside air is higher than the enthalpy of the return air; the enthalpy of the outside air is lower than the enthalpy of the return air and higher than the temperature of the supply air. Different outside air conditions were selected in order to represent typical weather data of Brazilians cities, as well as typical return air conditions. It was found that the enthalpy control strategy could promote an opportunity for energy savings mainly during mild nights and wintertime periods as well as during warm afternoons and summertime periods, depending on the outside air relative humidity. The proposed algorithm works well and can be integrated in some commercial automation software to reduce energy consumption and electricity demand. (author)

  8. Optimum operating conditions for a water purification process integrated to a heat transformer with energy recycling using neural network inverse

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, J.A.; Siqueiros, J.; Juarez-Romero, D. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos (UAEM), Av. Universidad No. 1001, Col. Chamilpa, Cuernavaca, Morelos C.P. 62209 (Mexico); Bassam, A. [Posgrado en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos (UAEM), Av. Universidad No. 1001, Col. Chamilpa, Cuernavaca, Morelos C.P. 62209 (Mexico)

    2009-04-15

    Artificial neural network inverse (ANNi) is applied to calculate the optimal operating conditions on the coefficient of performance (COP) for a water purification process integrated to an absorption heat transformer with energy recycling. An artificial neural network (ANN) model is developed to predict the COP which was increased with energy recycling. This ANN model takes into account the input and output temperatures for each one of the four components (absorber, generator, evaporator, and condenser), as well as two pressures and LiBr + H{sub 2}O concentrations. For the network, a feedforward with one hidden layer, a Levenberg-Marquardt learning algorithm, a hyperbolic tangent sigmoid transfer function and a linear transfer function were used. The best fitting training data set was obtained with three neurons in the hidden layer. On the validation data set, simulations and experimental data test were in good agreement (R > 0.99). This ANN model can be used to predict the COP when the input variables (operating conditions) are well known. However, to control the COP in the system, we developed a strategy to estimate the optimal input variables when a COP is required from ANNi. An optimization method (the Nelder-Mead simplex method) is used to fit the unknown input variable resulted from the ANNi. This methodology can be applied to control on-line the performance of the system. (author)

  9. Farmer Resettlements and Water Energy Stresses Arising From Aggravating Drought Conditions in Mahaweli River Watershed, Sri Lanka

    Science.gov (United States)

    Thabrew, L.

    2012-12-01

    Climate change is expected to cause significant changes in water quantity and water quality in river basins throughout the world, with particularly significant impacts in developing regions. Climate change effects are often exacerbated by other simultaneous activities in developing countries, such as population growth, reliance on subsistence agriculture, and expanding provision of electricity. Each of these activities requires access to readily-available freshwater. For example, population growth requires more water for irrigation as food production needs increase. Additionally, water is needed for generating electricity in hydropower facilities as well as other facilities, which require water to run steam turbines or to cool facilities. As such, many developing countries face the real and immediate need to anticipate and adapt to climatic stresses on water resources in both the agricultural and residential sectors. Water withdrawal in both of these sectors is largely driven by individual behaviors, such as electricity use in the home and irrigation practices on farmland, aggregated at the household, community, and regional level. Our ongoing project in Sri Lanka focuses on understanding aforementioned issues in coupled natural and human systems in the Mahaweli River Watershed (MWR) to inform decision-makers to streamline policies and strategies for effective adaptation to worsening drought conditions. MWR produces more than 60% of the rice demand and nearly 40% of the energy requirement of the country. Although irrigation is currently the sector that withdraws the most water, with government plans for resettling farmer communities and developing new urban centers in the region by 2030, electricity production is expected to compete for water against irrigation in the future. Thus, understanding the water-energy nexus is crucial to planning for conservation and efficiency. Through a pilot survey conducted by our interdisciplinary research team, in five locations in

  10. The use of shf-energy in the combined method of a conditioning of the Mogars grain

    International Nuclear Information System (INIS)

    Shanasharova, D.A.; Khakimzhanov, A.A.; Burtebayeva, D.T.

    2002-01-01

    A complex study of different stages of processing and production of bread-roll products on the basis of specifically local raw material is an actual problem of a contemporary technology of processing of agriculture products. During the development of new technologies of the production of wheaten bread with an addition of new high-productive sorts of 'Mogar' (the sort of Setaria', the family of cereals) is the special methods of a processing in order to improve a quality of a flour and to raise an efficiency of its application in bread - making production. The application of shf-fields (with the frequency of 2.45 GHz) is a practical value and scientific interest. The shf-energy is used for an influence onto a biological system of grains during its processing with the combined method of the conditioning. During this action the degree of the transformation of the shf-energy into a heat one in humid drain is determined by the rate of heating of grain mass, Δt/Δτ, where Δt is change of the temperature in the grain mass (in deg. C) and Δτ is time interval of the processing (in seconds). By experimental way it was established that the most intensive selection of energy, characterized by the rate of heating of drain mass of (0.19-0.21) deg. C/s, takes place during the humidification of drain up to (28-30) %, in the time of a simultaneous air blow-through. In order to avoid the process of denaturation of grain the grain mass was heated up to the temperature of (45-47) deg.C and up to an achievement of its humidity of (16-47) %. The maximum increase of flour yield up to (6-8) %, in the time of a decrease of an ash content by (0.18-0.21) %, was achieved at the optimal duration of moistening of (2.5-3.0) hours, that is essentially less (by (4-5) times than it is during the traditional processing. At the sometime, for experimental samples, the criterion of milling corresponded to the maximum values: K=37/49 and K=7.89. It is established, that during the processing of

  11. An energy-based equilibrium contact angle boundary condition on jagged surfaces for phase-field methods.

    Science.gov (United States)

    Frank, Florian; Liu, Chen; Scanziani, Alessio; Alpak, Faruk O; Riviere, Beatrice

    2018-08-01

    We consider an energy-based boundary condition to impose an equilibrium wetting angle for the Cahn-Hilliard-Navier-Stokes phase-field model on voxel-set-type computational domains. These domains typically stem from μCT (micro computed tomography) imaging of porous rock and approximate a (on μm scale) smooth domain with a certain resolution. Planar surfaces that are perpendicular to the main axes are naturally approximated by a layer of voxels. However, planar surfaces in any other directions and curved surfaces yield a jagged/topologically rough surface approximation by voxels. For the standard Cahn-Hilliard formulation, where the contact angle between the diffuse interface and the domain boundary (fluid-solid interface/wall) is 90°, jagged surfaces have no impact on the contact angle. However, a prescribed contact angle smaller or larger than 90° on jagged voxel surfaces is amplified. As a remedy, we propose the introduction of surface energy correction factors for each fluid-solid voxel face that counterbalance the difference of the voxel-set surface area with the underlying smooth one. The discretization of the model equations is performed with the discontinuous Galerkin method. However, the presented semi-analytical approach of correcting the surface energy is equally applicable to other direct numerical methods such as finite elements, finite volumes, or finite differences, since the correction factors appear in the strong formulation of the model. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. The effects of electrode cleaning and conditioning on the performance of high-energy, pulsed-power devices

    Energy Technology Data Exchange (ETDEWEB)

    Cuneo, M.E.

    1998-09-01

    High-energy pulsed-power devices routinely access field strengths above those at which broad-area, cathode-initiated, high-voltage vacuum-breakdown occur (> 1e7--3e7 V/m). Examples include magnetically-insulated-transmission-lines and current convolutes, high-current-density electron and ion diodes, high-power microwave devices, and cavities and other structures for electrostatic and RF accelerators. Energy deposited in anode surfaces may exceed anode plasma thermal-desorption creation thresholds on the time-scale of the pulse. Stimulated desorption by electron or photon bombardment can also lead to plasma formation on electrode or insulator surfaces. Device performance is limited above these thresholds, particularly in pulse length and energy, by the formation and expansion of plasmas formed primarily from electrode contaminants. In-situ conditioning techniques to modify and eliminate the contaminants through multiple high-voltage pulses, low base pressures, RF discharge cleaning, heating, surface coatings, and ion- and electron-beam surface treatment allow access to new regimes of performance through control of plasma formation and modification of the plasma properties. Experimental and theoretical progress from a variety of devices and small scale experiments with a variety of treatment methods will be reviewed and recommendations given for future work.

  13. International Energy Agency Building Energy Simulation Test and Diagnostic Method for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST): Volume 2: Cases E300-E545.

    Energy Technology Data Exchange (ETDEWEB)

    Neymark J.; Judkoff, R.

    2004-12-01

    This report documents an additional set of mechanical system test cases that are planned for inclusion in ANSI/ASHRAE STANDARD 140. The cases test a program's modeling capabilities on the working-fluid side of the coil, but in an hourly dynamic context over an expanded range of performance conditions. These cases help to scale the significance of disagreements that are less obvious in the steady-state cases. The report is Vol. 2 of HVAC BESTEST Volume 1. Volume 1 was limited to steady-state test cases that could be solved with analytical solutions. Volume 2 includes hourly dynamic effects, and other cases that cannot be solved analytically. NREL conducted this work in collaboration with the Tool Evaluation and Improvement Experts Group under the International Energy Agency (IEA) Solar Heating and Cooling Programme Task 22.

  14. Development of D-region electron and ion densities under various auroral conditions during the Energy Budget Campaign (EBC)

    International Nuclear Information System (INIS)

    Brekke, A.; Holt, O.; Friedrich, M.; Hansen, T.; Stauning, P.; Thrane, E.V.

    1985-01-01

    D-region electron density profiles and time variations were obtained during the Energy Budget Campaign 1980 by a partial reflection radar at Ramfjordmoen, Tromso, located between the rocket ranges at Andoya and Kiruna. The observations were made under various geophysical conditions which are illustrated by riometer observations. The partial reflection measurements indicate that the rockets were launched into a relatively stable D-region on two occasions, while it was somewhat more disturbed on the third. A comparison between the electron density profiles derived by the partial reflection technique and rocket borne probes and Faraday rotation experiments does indicate fair agreement during the quiet conditions, but relatively large discrepancies during disturbed conditions. Simultaneously derived electron density profiles, by use of the Faraday technique, and ion density profiles, by gridded electrostatic spheres mounted on the rocket payload, have made it possible to estimate the negative ion to electron density ratio lambda versus height. These values of lambda are within the range of model calculations. (author)

  15. Electricity Breakdown Management for Sarawak Energy: Use of Condition-Based Equipment for Detection of Defective Insulator

    Science.gov (United States)

    Tan, J. K.; Abas, N.

    2017-07-01

    Managing electricity breakdown is vital since an outage causes economic losses for customers and the utility companies. However, electricity breakdown is unavoidable due to some internal or external factors beyond our control. Electricity breakdown on overhead lines tend occur more frequently because it is prone to external disturbances such as animal, overgrown vegetation and defective pole top accessories. In Sarawak Energy Berhad (SEB), majority of the network are composed of overhead lines and hence, is more prone to failure. Conventional method of equipment inspection and fault finding are not effective to quickly identify the root cause of failure. SEB has engaged the use of corona discharge camera as condition-based monitoring equipment to carry out condition based inspection on the line in order to diagnose the condition of the lines prior to failure. Experimental testing has been carried out to determine the correlation between the corona discharge count and the level of defect on line insulator. The result shall be tabulated and will be used as reference for future scanning and diagnostic on any defect on the lines.

  16. Effects of Adult Feeding and Overwintering Conditions on Energy Reserves and Flight Performance of Emerald Ash Borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Tussey, Dylan A; Aukema, Brian H; Charvoz, Anthony M; Venette, Robert C

    2018-04-02

    Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive beetle from Asia, spreads through human-mediated movement and active flight. The effects of adult feeding and overwintering conditions on A. planipennis energy reserves (e.g., lipid, glycogen, and sugars) and flight are poorly understood. We conjectured that the potential energetic demands associated with the production of cryoprotectants might affect dispersal capacity and partially explain slower spread of A. planipennis in Minnesota than in the other states. Two studies sought to measure the effects of adult feeding on lipid content and flight capacity. Adult A. planipennis were fed shamel ash, Fraxinus uhdei Wenzig, leaves for 0-20 d after emergence, and half were flown on a custom flight mill for 24 h, before being frozen for comparative lipid analysis with a control group. The second study compared the effects of adult feeding on energy reserves and flight capacity of A. planipennis that were originally from St. Paul, Minnesota but overwintered in infested logs placed in Grand Rapids, Minnesota (low winter temperature, -34°C) or St. Paul, Minnesota (-26.3°C). Live adults consumed foliage at a constant rate, but lipid content (percentage of fresh mass) did not change with increases in feeding or flight. Adult glycogen content declined with flight and increased only slightly with feeding. Overwintering location affected survival rates but not energy reserves or flight capacity. These results suggest that the flight capacity of A. planipennis is largely determined before emergence, with no differences in energy reserves after cryoprotectant investment.

  17. Energy performance of solar-assisted liquid desiccant air-conditioning system for commercial building in main climate zones

    International Nuclear Information System (INIS)

    Qi, Ronghui; Lu, Lin; Huang, Yu

    2014-01-01

    Highlights: • Simulation of solar liquid desiccant AC system in four climate regions was conducted. • System performance was determined by relationship of sensible and latent cooling load. • For humid area, saving amount is large by handling latent load with solar energy. • For dry area, electricity saving rate is considerable due to the high COP of chillers. • For buildings with mild SHR, the system performance was not as good as others. - Abstract: Liquid desiccant air-conditioning (LDAC) system, which consists of a liquid desiccant ventilation system for dehumidification and an air-handling unit for cooling, has become a promising alternative for conventional technology. To evaluate its feasibility and applicability, the simulation of solar-assisted LDAC (SLDAC) in commercial buildings in five cities of four main climate regions were conducted, including Singapore in Tropical, Houston and Beijing in Temperate, Boulder in Arid and Los Angeles in Mediterranean. Results showed that the system’s performance was seriously affected by the ratios of building’s sensible and latent cooling load. For buildings located in humid areas with low sensible-total heat ratio (SHR), the electricity energy reduction of SLDAC was high, about 450 MW h in Houston and Singapore, which accounted for 40% of the total energy consumption in cooling seasons. The cost payback period was as short as approximately 7 years. The main reason is that the energy required for handling the moisture could be saved by liquid desiccant dehumidification, and the regeneration heat could be covered by solar collectors. For buildings in dry climate with high SHR, the total cooling load was low, but up to 45% electricity of AC system could be saved in Boulder because the chiller COP could be significantly improved during more than 70% operation time. The cost payback period was around 22 years, which was acceptable. However, for the buildings with mild SHR, such as those in Beijing and Los

  18. Hydropeaking in Nordic rivers - combined analysis from effects of changing climate conditions and energy demands to river regimes

    Science.gov (United States)

    Ashraf, Faisal Bin; Marttila, Hannu; Torabi Haghighi, Ali; Alfredsen, Knut; Riml, Joakim; Kløve, Bjørn

    2017-04-01

    Increasing national and international demands for more flexible management of the energy resources with more non-storable renewables being used in adapting to the ongoing climate change will influence hydropower operations. Damming and regulation practices of river systems causes homogenization of long term river dynamics but also higher temporal sub-daily flow variations i.e. hydropeaking. In Nordic countries, many major rivers and lakes are regulated for hydropower purposes, which have caused considerable changes in river biotic, hydrologic and morphologic structures. Due to rapidly changing energy markets in the Nordic countries (deregulation of the power market and adding of renewable but intermittent sources of energy like, wind, solar, etc.) sub-daily flow conditions are under change within regulated river systems due to the increased demand on hydropower for providing balancing power. However, holistic analysis from changes in energy markets and its effect on sub-daily river regimes is lacking. This study analyzes the effects of hydropeaking on river regime in Finland, Sweden and Norway using long term high resolution data (15 minutes to hourly time interval) from 72 pristine and 136 regulated rivers with large spatial coverage across Fennoscandia. Since the sub-daily discharge variation is masked through the monthly or daily analyzes, in order to quantify these changes high resolution data is needed. In our study we will document, characterize and classify the impacts of sub-daily flow variation due to regulation and climatic variation on various river systems in Fennoscandia. Further, with increasing social demands for ecosystem services in regulated rivers, it is important to evaluate the new demand and update hydropower operation plan accordingly. We will analyse ecological response relationships along gradients of hydrological alteration for the biological communities, processes of river ecosystems and climate boundaries together with considering the

  19. Predicting the impact of chronic health conditions on workplace productivity and accidents: results from two US Department of Energy national laboratories.

    Science.gov (United States)

    Frey, Jodi Jacobson; Osteen, Philip J; Berglund, Patricia A; Jinnett, Kimberly; Ko, Jungyai

    2015-04-01

    Examine associations of chronic health conditions on workplace productivity and accidents among US Department of Energy employees. The Health and Work Performance Questionnaire-Select was administered to a random sample of two Department of Energy national laboratory employees (46% response rate; N = 1854). The majority (87.4%) reported having one or more chronic health conditions, with 43.4% reporting four or more conditions. A population-attributable risk proportions analysis suggests improvements of 4.5% in absenteeism, 5.1% in presenteeism, 8.9% in productivity, and 77% of accidents by reducing the number of conditions by one level. Depression was the only health condition associated with all four outcomes. Results suggest that chronic conditions in this workforce are prevalent and costly. Efforts to prevent or reduce condition comorbidity among employees with multiple conditions can significantly reduce costs and workplace accident rates.

  20. Energy

    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)

  1. Biofouling community composition across a range of environmental conditions and geographical locations suitable for floating marine renewable energy generation.

    Science.gov (United States)

    Macleod, Adrian K; Stanley, Michele S; Day, John G; Cook, Elizabeth J

    2016-01-01

    Knowledge of biofouling typical of marine structures is essential for engineers to define appropriate loading criteria in addition to informing other stakeholders about the ecological implications of creating novel artificial environments. There is a lack of information regarding biofouling community composition (including weight and density characteristics) on floating structures associated with future marine renewable energy generation technologies. A network of navigation buoys were identified across a range of geographical areas, environmental conditions (tidal flow speed, temperature and salinity), and deployment durations suitable for future developments. Despite the perceived importance of environmental and temporal factors, geographical location explained the greatest proportion of the observed variation in community composition, emphasising the importance of considering geography when assessing the impact of biofouling on device functioning and associated ecology. The principal taxa associated with variation in biofouling community composition were mussels (Mytilus edulis), which were also important when determining loading criteria.

  2. Temperature and Humidity Control in Air-Conditioned Buildings with lower Energy Demand and increased Indoor Air Quality

    DEFF Research Database (Denmark)

    Paul, Joachim; Martos, E. T.

    2003-01-01

    Air-conditioning is not only a matter of temperature control. Thermal comfort and good indoor air quality are mainly a matter of humidity. Human health and well being may suffer seriously from inadequate humidity and/or too low temperatures in a room. A case study involving supermarket air......%. For indoor air temperature and humidity control, the use of an ice slurry (´Binary Ice´)was compared to conventional chilled water. The use of Binary Ice instead of chilled water makes the air handling and air distribution installation much simpler, recirculation of air becomes obsolete, and a higher portion...... of ambient air can be supplied, thus improving the indoor air quality still further. Reheating of air is not necessary when using Binary Ice. The introduction of chilled air into a room requires a different type of air outlet, however. When using Binary Ice, energy savings are high for climates with low...

  3. Linking atmospheric synoptic transport, cloud phase, surface energy fluxes, and sea-ice growth: observations of midwinter SHEBA conditions

    Science.gov (United States)

    Persson, P. Ola G.; Shupe, Matthew D.; Perovich, Don; Solomon, Amy

    2017-08-01

    Observations from the Surface Heat Budget of the Arctic Ocean (SHEBA) project are used to describe a sequence of events linking midwinter long-range advection of atmospheric heat and moisture into the Arctic Basin, formation of supercooled liquid water clouds, enhancement of net surface energy fluxes through increased downwelling longwave radiation, and reduction in near-surface conductive heat flux loss due to a warming of the surface, thereby leading to a reduction in sea-ice bottom growth. The analyses provide details of two events during Jan. 1-12, 1998, one entering the Arctic through Fram Strait and the other from northeast Siberia; winter statistics extend the results. Both deep, precipitating frontal clouds and post-frontal stratocumulus clouds impact the surface radiation and energy budget. Cloud liquid water, occurring preferentially in stratocumulus clouds extending into the base of the inversion, provides the strongest impact on surface radiation and hence modulates the surface forcing, as found previously. The observations suggest a minimum water vapor threshold, likely case dependent, for producing liquid water clouds. Through responses to the radiative forcing and surface warming, this cloud liquid water also modulates the turbulent and conductive heat fluxes, and produces a thermal wave penetrating into the sea ice. About 20-33 % of the observed variations of bottom ice growth can be directly linked to variations in surface conductive heat flux, with retarded ice growth occurring several days after these moisture plumes reduce the surface conductive heat flux. This sequence of events modulate pack-ice wintertime environmental conditions and total ice growth, and has implications for the annual sea-ice evolution, especially for the current conditions of extensive thinner ice.

  4. Energy

    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.)

  5. Stochastic Model Predictive Fault Tolerant Control Based on Conditional Value at Risk for Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Yun-Tao Shi

    2018-01-01

    Full Text Available Wind energy has been drawing considerable attention in recent years. However, due to the random nature of wind and high failure rate of wind energy conversion systems (WECSs, how to implement fault-tolerant WECS control is becoming a significant issue. This paper addresses the fault-tolerant control problem of a WECS with a probable actuator fault. A new stochastic model predictive control (SMPC fault-tolerant controller with the Conditional Value at Risk (CVaR objective function is proposed in this paper. First, the Markov jump linear model is used to describe the WECS dynamics, which are affected by many stochastic factors, like the wind. The Markov jump linear model can precisely model the random WECS properties. Second, the scenario-based SMPC is used as the controller to address the control problem of the WECS. With this controller, all the possible realizations of the disturbance in prediction horizon are enumerated by scenario trees so that an uncertain SMPC problem can be transformed into a deterministic model predictive control (MPC problem. Finally, the CVaR object function is adopted to improve the fault-tolerant control performance of the SMPC controller. CVaR can provide a balance between the performance and random failure risks of the system. The Min-Max performance index is introduced to compare the fault-tolerant control performance with the proposed controller. The comparison results show that the proposed method has better fault-tolerant control performance.

  6. Quantifying the Effects of Biomass Market Conditions and Policy Incentives on Economically Feasible Sites to Establish Dedicated Energy Crops

    Directory of Open Access Journals (Sweden)

    Sandhya Nepal

    2015-11-01

    Full Text Available This study used a spatially-explicit model to identify the amount and spatial distribution of economically feasible sites for establishing dedicated energy crops under various market and policy scenarios. A sensitivity analysis was performed for a biomass market with different discount rates and biomass prices as well as policy scenarios including propriety tax exemption, carbon offset payments, and the inclusion of farmland for biomass production. The model was applied to a four-county study area in Kentucky representing conditions commonly found in the Ohio River Valley. Results showed that both biomass price and discount rate have a can strongly influence the amount of economically efficient sites. Rising the biomass price by 5 $·t−1 and lowering discount rate by 1% from the baseline scenario (40 $·t−1 and 5% resulted in an over fourteen fold increment. Property tax exemption resulted in a fourfold increase, a carbon payment on only 1 $·t−1 caused a twelve fold increase and extending the landbase from marginal land to farmland only slightly increase the economically efficient sites. These results provide an objective evaluation of market and policy scenarios in terms of their potential to increase land availability for establishing dedicated energy crops and to promote the bioenergy industry.

  7. Mapping land water and energy balance relations through conditional sampling of remote sensing estimates of atmospheric forcing and surface states

    Science.gov (United States)

    Farhadi, Leila; Entekhabi, Dara; Salvucci, Guido

    2016-04-01

    In this study, we develop and apply a mapping estimation capability for key unknown parameters that link the surface water and energy balance equations. The method is applied to the Gourma region in West Africa. The accuracy of the estimation method at point scale was previously examined using flux tower data. In this study, the capability is scaled to be applicable with remotely sensed data products and hence allow mapping. Parameters of the system are estimated through a process that links atmospheric forcing (precipitation and incident radiation), surface states, and unknown parameters. Based on conditional averaging of land surface temperature and moisture states, respectively, a single objective function is posed that measures moisture and temperature-dependent errors solely in terms of observed forcings and surface states. This objective function is minimized with respect to parameters to identify evapotranspiration and drainage models and estimate water and energy balance flux components. The uncertainty of the estimated parameters (and associated statistical confidence limits) is obtained through the inverse of Hessian of the objective function, which is an approximation of the covariance matrix. This calibration-free method is applied to the mesoscale region of Gourma in West Africa using multiplatform remote sensing data. The retrievals are verified against tower-flux field site data and physiographic characteristics of the region. The focus is to find the functional form of the evaporative fraction dependence on soil moisture, a key closure function for surface and subsurface heat and moisture dynamics, using remote sensing data.

  8. THE PREDICTION OF pH BY GIBBS FREE ENERGY MINIMIZATION IN THE SUMP SOLUTION UNDER LOCA CONDITION OF PWR

    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.

  9. Initial conditions for inflation and the energy scale of SUSY-breaking from the (nearly) gaussian sky

    CERN Document Server

    Álvarez-Gaumé, Luis; Jimenez, Raul

    We show how general initial conditions for small field inflation can be obtained in multi-field models. This is provided by non-linear angular friction terms in the inflaton that provide a phase of non-slow-roll inflation before the slow-roll inflation phase. This in turn provides a natural mechanism to star small-field slow-roll at nearly zero velocity for arbitrary initial conditions. We also show that there is a relation between the scale of SUSY breaking sqrt (f) and the amount of non-gaussian fluctuations generated by the inflaton. In particular, we show that in the local non-gaussian shape there exists the relation sqrt (f) = 10^{13} GeV sqrt (f_NL). With current observational limits from Planck, and adopting the minimum amount of non-gaussian fluctuations allowed by single-field inflation, this provides a very tight constraint for the SUSY breaking energy scale sqrt (f) = 3-7 x 10^{13} GeV at 95% confidence. Further limits, or detection, from next year's Planck polarisation data will further tighten th...

  10. Albedo boundary conditions for global calculations of thermal nuclear reactors with the model of discrete ordinates to two energy groups

    International Nuclear Information System (INIS)

    Nunes, Carlos Eduardo de Araujo

    2011-01-01

    As neutron fission events do not take place in the non-multiplying regions of nuclear reactors, e.g., moderator, reflector, and structural core, these regions do not generate power and the computational efficiency of nuclear reactor global calculations can hence be improved by eliminating the explicit numerical calculations within the non-multiplying regions around the active domain. Discussed here is the computational efficiency of approximate discrete ordinates (SN) albedo boundary conditions for two-energy group eigenvalue problems in X, Y geometry. Albedo, the Latin word for w hiteness , was originally defined as the fraction of incident light reflected diffusely by a surface. This Latin word has remained the usual scientific term in astronomy and in this dissertation this concept is extended for the reflection of neutrons. The non-standard SN albedo substitutes approximately the reflector region around the active domain, as we neglect the transverse leakage terms within the non-multiplying reflector. Should the problem have no transverse leakage terms, i.e., one dimensional slab geometry, then the offered albedo boundary conditions are exact. By computational efficiency we mean analyzing the accuracy of the numerical results versus the CPU execution time of each run for a given model problem. Numerical results to two 1/4 symmetric test problems are shown to illustrate this efficiency analysis. (author)

  11. Reduced energy reqirement for air conditioning by using air diffusion with air flow from floor to ceiling

    Energy Technology Data Exchange (ETDEWEB)

    Bach, H; Dittes, W; Mangelsdorf, R; Detzer, R; Jungbaeck, E; Fitzner, K; Radtke, W; Soethout, F

    1982-02-01

    The condition of the air in the occupied zone in airconditioned rooms is influenced by the mixing of supply air with room air. When supplying air from the ceiling there is a mixing all over the room, when supplying from the floor or from desks there is a mixing region only in the lower area. Above this their is warm air from which the return air is drawn. For air supply from below the cooling load can be decreased. In combination with the possible enthalpy difference between room air and supply air this decrease of the cooling load influences the necessary air rate. The interdependence of various air conditioning systems and various air temperatures is shown with a computer program. The load factor for various air distribution system at various cooling loads have been measured in a room of (8 x 5)m/sup 2/ x 3m. Experiments in a smaller model room (scale 1:3) showed how the heat was transported from the mixing region to the stratification region. The theoretically gained influence of the supply air jets of the height of the mixing region and on the load rate could be verified by the experiments. For the design of the fresh air rate, experience has been gained by measurements with tracegas (N/sub 2/O) in a third room. In comparing calculations the annual energy consumption has been computed for a building assuming various air conditioning systems and typical operation data. From experience with the existing systems the conclusions have been drawn how air distribution from floor to ceiling can be installed and operated.

  12. Notes for the ESCWA meeting on the impact of changing conditions in the oil market on energy policies

    International Nuclear Information System (INIS)

    Bizri, O.F.

    1992-01-01

    A brief review is given of the factors which affect the world's demand for petroleum. These include the development of alternative energy sources, energy efficiency and energy conservation, economic growth and oil consumption in the Third World. The importance of further R and D in energy technologies is stressed. (UK)

  13. Energy

    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

  14. Impact of the Growing Population and Energy Demand on the Climatic Conditions of the Indo-Gangetic Basin

    Science.gov (United States)

    Singh, R. P.; Prasad, A. K.; Kafatos, M.

    2005-12-01

    The Indo-Gangetic (IG) basin is one of the largest basins in the world which is densely populated and suffers with dense fog, haze and smog during winter season. About 500 million people live in the IG basin and due to the dense fog, haze and smog day to day life suffers. India is the third largest producer of the coal in the world and a large share is used in power and industrial sector. The coal used in the power plants is of poor quality (mostly E-F grade or lignite) with high ash content (35-50%) and low calorific value. India's energy consumption has increased 208% from 4.16 quadrillion Btu (quads) in 1980 to 12.8 quads in 2001 with a coal share of ~50.9%. Recent studies using satellite (Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging SpectroRadiometer (MISR)) and AERONET measurements show high aerosol optical depth (AOD) representing the intense air pollution over the IG basin that persists throughout the year. Such high concentrations of AOD show spatial and temporal variations which are controlled by the meteorological conditions (wind pattern, relative humidity, air temperature etc.) and topography. The high AOD observed over the IG basin is attributed to the emissions of fossil fuel SO2 and black carbon which has increased about 6 fold since 1930. The high AOD over the IG basin is attributed to the huge emission from the dense network of coal based thermal power plants in the IG basin and its surroundings that may be the probable cause for the atmospheric brown clouds (ABC). The impact of aerosol parameters on the climatic conditions will be discussed.

  15. Saving 50% of energy in air conditioning and refrigeration; 50% de ahorro de energia en aire acondicionado y refrigeracion

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez De la Fuente, Rodolfo Javier [Instituto para la Proteccion Ambiental de Nuevo Leon-CAINTRA, Nuevo Leon (Mexico); Bolado Tamez, Jaime Antonio [Industrias AlEn S. A. de C. V., Monterrey (Mexico)

    1998-12-31

    Due to the fact that the air conditioning systems represent up to 70% of the energy consumption in our buildings, to the constant raise of the electric tariffs and to the increment of temperatures in Nuevo Leon State, as well as the restrictions on the use of some refrigerant fluids because of its potential damage to the ozone layer (Montreal Protocol) and the preferential use of refrigerants with low global heating potential (Kioto Protocol). The Camara de la Industria de la Transformacion de Nuevo Leon (Nuevo Leon`s Transformation Industry Chamber) through the Instituto para la Proteccion Ambiental de Nuevo Leon (Nuevo Leon`s Institute for Environmental Protection), create the program ECO-REFRIGERATION whose three missions are: Increase the efficiency of air conditioning and refrigeration equipment, promote the substitution of refrigerants and extend the benefits of these projects to the community in general. [Espanol] Debido a que los sistemas de climatizacion representan hasta el 70% de consumo energetico en nuestros inmuebles, al constante incremento de las tarifas electricas, el incremento de las temperaturas en Nuevo Leon, asi como la restriccion del uso de algunos refrigerantes por su potencial de dano de la capa de ozono (Protocolo de Montreal) y el uso preferente de refrigerantes con bajo potencial de calentamiento global (Protocolo de Kioto), la Camara de la Industria de la Transformacion de Nuevo Leon a traves del Instituto para la Proteccion Ambiental de Nuevo Leon crean el Programa ECO-REFRIGERACION cuyas tres misiones son: Incrementar la eficiencia de los equipos de aire acondicionado y refrigeracion, promover la sustitucion de refrigerantes y extender los beneficios de este proyecto a la comunidad en general.

  16. Saving 50% of energy in air conditioning and refrigeration; 50% de ahorro de energia en aire acondicionado y refrigeracion

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez De la Fuente, Rodolfo Javier [Instituto para la Proteccion Ambiental de Nuevo Leon-CAINTRA, Nuevo Leon (Mexico); Bolado Tamez, Jaime Antonio [Industrias AlEn S. A. de C. V., Monterrey (Mexico)

    1999-12-31

    Due to the fact that the air conditioning systems represent up to 70% of the energy consumption in our buildings, to the constant raise of the electric tariffs and to the increment of temperatures in Nuevo Leon State, as well as the restrictions on the use of some refrigerant fluids because of its potential damage to the ozone layer (Montreal Protocol) and the preferential use of refrigerants with low global heating potential (Kioto Protocol). The Camara de la Industria de la Transformacion de Nuevo Leon (Nuevo Leon`s Transformation Industry Chamber) through the Instituto para la Proteccion Ambiental de Nuevo Leon (Nuevo Leon`s Institute for Environmental Protection), create the program ECO-REFRIGERATION whose three missions are: Increase the efficiency of air conditioning and refrigeration equipment, promote the substitution of refrigerants and extend the benefits of these projects to the community in general. [Espanol] Debido a que los sistemas de climatizacion representan hasta el 70% de consumo energetico en nuestros inmuebles, al constante incremento de las tarifas electricas, el incremento de las temperaturas en Nuevo Leon, asi como la restriccion del uso de algunos refrigerantes por su potencial de dano de la capa de ozono (Protocolo de Montreal) y el uso preferente de refrigerantes con bajo potencial de calentamiento global (Protocolo de Kioto), la Camara de la Industria de la Transformacion de Nuevo Leon a traves del Instituto para la Proteccion Ambiental de Nuevo Leon crean el Programa ECO-REFRIGERACION cuyas tres misiones son: Incrementar la eficiencia de los equipos de aire acondicionado y refrigeracion, promover la sustitucion de refrigerantes y extender los beneficios de este proyecto a la comunidad en general.

  17. Energy

    CERN Document Server

    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.

  18. Energy Security of Army Installations and Islanding Methodologies: A Multiple Criteria Decision Aid to Innovation with Emergent Conditions of the Energy Environment

    Science.gov (United States)

    2010-06-16

    Clemen and Reilly (2001) Risk analysis Haimes (2009); Kaplan et al. (2001): Lowrance (1976); Kaplan and Garrick (1981) Source: The US Army Energy...collect solar energy and convert to heat (NREL presentation) • Wind turbines capture energy in wind and convert it into electricity (NREL

  19. Modeling of dynamic conditions of operation of wind turbines (WT and choice of environmentally efficient and energy economic technology of wind power energy transformation

    Directory of Open Access Journals (Sweden)

    Bespalov Vadim

    2017-01-01

    Full Text Available Wind energy usage is one of the promising areas among renewable energy sources. The article considers a methodical approach to the modeling and selection of environmentally efficient and energy-efficient wind turbines at the design stage, taking into account the characteristics of the natural-territorial complex and the specific anthropogenic load on the territory of the WT location.

  20. Hot cell renovation in the spent fuel conditioning process facility at the Korea Atomic Energy Research Institute

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Seung Nam; Lee, Jong Kwang; Park, Byung Suk; Cho, Il Je; Kim, Ki Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The advanced spent fuel conditioning process facility (ACPF) of the irradiated materials examination facility (IMEF) at the Korea Atomic Energy Research Institute (KAERI) has been renovated to implement a lab scale electrolytic reduction process for pyroprocessing. The interior and exterior structures of the ACPF hot cell have been modified under the current renovation project for the experimentation of the electrolytic reduction process using spent nuclear fuel. The most important aspect of this renovation was the installation of the argon compartment within the hot cell. For the design and system implementation of the argon compartment system, a full-scale mock-up test and a three-dimensional (3D) simulation test were conducted in advance. The remodeling and repairing of the process cell (M8a), the maintenance cell (M8b), the isolation room, and their utilities were also planned through this simulation to accommodate the designed argon compartment system. Based on the considered refurbishment workflow, previous equipment in the M8 cell, including vessels and pipes, were removed and disposed of successfully after a zoning smear survey and decontamination, and new equipment with advanced functions and specifications were installed in the hot cell. Finally, the operating area and isolation room were also refurbished to meet the requirements of the improved hot cell facility.

  1. Dual direction blower system powered by solar energy to reduce car cabin temperature in open parking condition

    Science.gov (United States)

    Hamdan, N. S.; Radzi, M. F. M.; Damanhuri, A. A. M.; Mokhtar, S. N.

    2017-10-01

    El-nino phenomenon that strikes Malaysia with temperature recorded more than 35°C can lead to extreme temperature rise in car cabin up to 80°C. Various problems will arise due to this extreme rising of temperature such as the occupant are vulnerable to heat stroke, emission of benzene gas that can cause cancer due to reaction of high temperature with interior compartments, and damage of compartments in the car. The current solution available to reduce car cabin temperature including tinted of window and portable heat rejection device that are available in the market. As an alternative to reduce car cabin temperature, this project modifies the car’s air conditioning blower motor into dual direction powered by solar energy and identifies its influence to temperature inside the car, parked under scorching sun. By reducing the car cabin temperature up to 10°C which equal to 14% of reduction in the car cabin temperature, this simple proposed system aims to provide comfort to users due to its capability in improving the quality of air and moisture in the car cabin.

  2. Tenskinmetric Evaluation of Surface Energy Changes in Adult Skin: Evidence from 834 Normal Subjects Monitored in Controlled Conditions

    Directory of Open Access Journals (Sweden)

    Camilla Dal Bosco

    2014-03-01

    Full Text Available To evaluate the influence of the skin aging critical level on the adult skin epidermal functional state, an improved analytical method based on the skin surface energetic measurement (TVS modeling was developed. Tenskinmetric measurements were carried out non-invasively in controlled conditions by contact angle method using only a water-drop as reference standard liquid. Adult skin was monitored by TVS Observatory according to a specific and controlled thermal protocol (Camianta protocol in use at the interconnected “Mamma Margherita Terme spa” of Terme Euganee. From June to November 2013, the surface free energy and the epidermal hydration level of adult skin were evaluated on arrival of 265 male and 569 female adult volunteers (51–90 years of age and when they departed 2 weeks later. Sensitive measurements were carried out at 0.1 mN/m. High test compliance was obtained (93.2% of all guests. Very interesting results are obtained. The high sensitivity and discrimination power of tenskinmetry combined with a thermal Camianta protocol demonstrate the possibility to evaluate at baseline level the surface energetic changes and the skin reactivity which occurs on adult skin.

  3. Energy

    CERN Document Server

    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...

  4. The effect of low energy helium ion irradiation on tungsten-tantalum (W-Ta) alloys under fusion relevant conditions

    Science.gov (United States)

    Gonderman, S.; Tripathi, J. K.; Novakowski, T. J.; Sizyuk, T.; Hassanein, A.

    2017-08-01

    Currently, tungsten remains the best candidate for plasma-facing components (PFCs) for future fusion devices because of its high melting point, low erosion, and strong mechanical properties. However, continued investigation has shown tungsten to undergo severe morphology changes under fusion-like conditions. These results motivate the study of innovative PFC materials which are resistant to surface morphology evolution. The goal of this work is to examine tungsten-tantalum (W-Ta) alloys, a potential PFC material, and their response to low energy helium ion irradiation. Specifically, W-Ta samples are exposed to 100 eV helium irradiations with a flux of 1.15 × 1021 ions m-2 s-1, at 873 K, 1023 K, and 1173 K for 1 h duration. Scanning electron microscopy (SEM) reveals significant changes in surface deterioration due to helium ion irradiation as a function of both temperature and tantalum concentration in W-Ta samples. X-Ray Diffraction (XRD) studies show a slight lattice parameter expansion in W-Ta alloy samples compared to pure W samples. The observed lattice parameter expansion in W-Ta alloy samples (proportional to increasing Ta wt.% concentrations) reflect significant differences observed in the evolution of surface morphology, i.e., fuzz development processes for both increasing Ta wt.% concentration and target temperature. These results suggest a correlation between the observed morphology differences and the induced crystal structure change caused by the presence of tantalum. Shifts in the XRD peaks before and after 100 eV helium irradiation with a flux of 1.15 × 1021 ions m-2 s-1, 1023 K, for 1 h showed a significant difference in the magnitude of the shift. This has suggested a possible link between the atomic spacing of the material and the accumulated damage. Ongoing research is needed on W-Ta alloys and other innovative materials for their application as irradiation resistant materials in future fusion or irradiation environments.

  5. Energy and exergy performance analysis of a marine rotary desiccant air-conditioning system based on orthogonal experiment

    International Nuclear Information System (INIS)

    Zhu, Jun; Chen, Wu

    2014-01-01

    A novel marine rotary desiccant A/C (air-conditioning) system was developed and studied to improve energy utilization efficiency of ship A/C. The orthogonal experiment was first carried out to investigate the influence of various parameters of the marine rotary desiccant A/C system. During the orthogonal experiment the analysis of variance was used to exclude interference from the secondary influencing factor on system performance. The significant influencing factors of system were studied in great detail using the first and second laws of thermodynamics to find optimal setting parameters for best system performance. It is suggested from the analysis results that as regeneration temperature increases, the COP th (thermal coefficient of performance) and exergy efficiency of system (η e ) decreases by 46.9% and 38.8% respectively. They decrease in proportion to the increase of the temperature. η e reaches its maximum value of about 23.5% when the inlet humidity ratio of process air is 22 g/kg. Besides, the exergy loss of system concentrates on the regeneration air heater, the desiccant wheel and the regeneration air leaving the desiccant wheel, which account for 68.4%–81% of the total exergy loss. It can be concluded that applying the marine rotary desiccant A/C in high-temperature and high-humidity marine environment is advantageous. - Highlights: • Significant influencing factors of the system are found by the analysis of variance. • The change trends of the COP th and the η e are nearly proportional with the regeneration temperature. • The η e reaches its maximum value (about 23.5%) when the inlet humidity ratio of process air is 22 g/kg. • The contribution rate of the dry-bulb temperature of fresh air is up to 73.91% for the COP th . • Applying the marine rotary desiccant A/C in high-temperature and high-humidity marine environment is advantageous

  6. Applying Dynamic Energy Budget (DEB) theory to simulate growth and bio-energetics of blue mussels under low seston conditions

    Science.gov (United States)

    Rosland, R.; Strand, Ø.; Alunno-Bruscia, M.; Bacher, C.; Strohmeier, T.

    2009-08-01

    A Dynamic Energy Budget (DEB) model for simulation of growth and bioenergetics of blue mussels ( Mytilus edulis) has been tested in three low seston sites in southern Norway. The observations comprise four datasets from laboratory experiments (physiological and biometrical mussel data) and three datasets from in situ growth experiments (biometrical mussel data). Additional in situ data from commercial farms in southern Norway were used for estimation of biometrical relationships in the mussels. Three DEB parameters (shape coefficient, half saturation coefficient, and somatic maintenance rate coefficient) were estimated from experimental data, and the estimated parameters were complemented with parameter values from literature to establish a basic parameter set. Model simulations based on the basic parameter set and site specific environmental forcing matched fairly well with observations, but the model was not successful in simulating growth at the extreme low seston regimes in the laboratory experiments in which the long period of negative growth caused negative reproductive mass. Sensitivity analysis indicated that the model was moderately sensitive to changes in the parameter and initial conditions. The results show the robust properties of the DEB model as it manages to simulate mussel growth in several independent datasets from a common basic parameter set. However, the results also demonstrate limitations of Chl a as a food proxy for blue mussels and limitations of the DEB model to simulate long term starvation. Future work should aim at establishing better food proxies and improving the model formulations of the processes involved in food ingestion and assimilation. The current DEB model should also be elaborated to allow shrinking in the structural tissue in order to produce more realistic growth simulations during long periods of starvation.

  7. Energy, institutions and development: rightfulness and institutional conditions of a spreading of renewable energies in developing countries. The example of power generation for networks

    International Nuclear Information System (INIS)

    Richard, M.

    2004-01-01

    This study treats of the rightfulness of the promotion of renewable energy sources in a developing country like Brazil. It examines the economical and financial barriers to get over and the mechanisms necessary to be implemented to sustain the investment in renewable energy sources: institutional security, regulatory and administrative stability, long-term warranty, consistency between actions, transparency, credibility etc. (J.S.)

  8. Future Air Conditioning Energy Consumption in Developing Countries and what can be done about it: The Potential of Efficiency in the Residential Sector

    OpenAIRE

    McNeil, Michael A.; Letschert, Virginie E.

    2008-01-01

    The dynamics of air conditioning are of particular interest to energy analysts, both because of the high energy consumption of this product, but also its disproportionate impact on peak load. This paper addresses the special role of this end use as a driver of residential electricity consumption in rapidly developing economies. Recent history has shown that air conditioner ownership can grow grows more rapidly than economic growth in warm-climate countries. In 1990, less than a percent o...

  9. Life-Cycle Energy Use and Greenhouse Gas Emissions Analysis for Bio-Liquid Jet Fuel from Open Pond-Based Micro-Algae under China Conditions

    OpenAIRE

    Xunmin Ou; Xiaoyu Yan; Xu Zhang; Xiliang Zhang

    2013-01-01

    A life-cycle analysis (LCA) of greenhouse gas (GHG) emissions and energy use was performed to study bio-jet fuel (BJF) production from micro-algae grown in open ponds under Chinese conditions using the Tsinghua University LCA Model (TLCAM). Attention was paid to energy recovery through biogas production and cogeneration of heat and power (CHP) from the residual biomass after oil extraction, including fugitive methane (CH 4 ) emissions during the production of biogas and nitrous oxide (N 2 O) ...

  10. Building America Case Study: Effect of Ducted HPWH on Space Conditioning and Water Heating Energy Use - Central Florida Lab Home, Cocoa, Florida

    Energy Technology Data Exchange (ETDEWEB)

    C. Colon, E. Martin, and D. Parker

    2017-04-01

    The purpose of this research is to investigate the impact of ducted heat pump water heaters (HPWH's) on space conditioning and water heating energy use in residential applications. Two identical HPWH's, each of 60 gallon capacity were tested side by side at the Flexible Residential Test facility (FRTF) laboratories of the Florida Solar Energy Center (FSEC) campus in Cocoa, Florida. The water heating experiments were run in each test house from July 2014 until February 2015.

  11. MVP/GMVP 2: general purpose Monte Carlo codes for neutron and photon transport calculations based on continuous energy and multigroup methods

    International Nuclear Information System (INIS)

    Nagaya, Yasunobu; Okumura, Keisuke; Mori, Takamasa; Nakagawa, Masayuki

    2005-06-01

    In order to realize fast and accurate Monte Carlo simulation of neutron and photon transport problems, two vectorized Monte Carlo codes MVP and GMVP have been developed at JAERI. MVP is based on the continuous energy model and GMVP is on the multigroup model. Compared with conventional scalar codes, these codes achieve higher computation speed by a factor of 10 or more on vector super-computers. Both codes have sufficient functions for production use by adopting accurate physics model, geometry description capability and variance reduction techniques. The first version of the codes was released in 1994. They have been extensively improved and new functions have been implemented. The major improvements and new functions are (1) capability to treat the scattering model expressed with File 6 of the ENDF-6 format, (2) time-dependent tallies, (3) reaction rate calculation with the pointwise response function, (4) flexible source specification, (5) continuous-energy calculation at arbitrary temperatures, (6) estimation of real variances in eigenvalue problems, (7) point detector and surface crossing estimators, (8) statistical geometry model, (9) function of reactor noise analysis (simulation of the Feynman-α experiment), (10) arbitrary shaped lattice boundary, (11) periodic boundary condition, (12) parallelization with standard libraries (MPI, PVM), (13) supporting many platforms, etc. This report describes the physical model, geometry description method used in the codes, new functions and how to use them. (author)

  12. Load leveling air conditioning technology development by unused energy high-level utilization. Summary of lectures given at the achievement report meeting; Miriyo energy kodo katsuyo fuka heijunka reidanbo gijutsu kaihatsu. Seika hokokukai koen yoshishu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This paper summarizes lectures given at the research and development achievement report meeting on load leveling air conditioning technologies utilizing unutilized energies at high levels. The lecture titled 'the current status and future problems in heat supply industries' given by the manager of the Heat Supply Industry Department at the Agency of Natural Resources and Energy explained the heat supply businesses in relation with global environment issues, electric power load leveling, and cogeneration. The lecture titled 'improvement of cities to energy saving type cities and district air conditioning systems' given by a construction official at the Ministry of Construction explained the guideline (draft) for introduction of district air conditioning systems as to their purpose, positioning, procedure for discussing the introduction, and procedure for its implementation as a business. The lecture titled 'the recent trend inside and outside the country around unutilized energies' given by Professor Tanazawa at the Tokyo University of Agriculture and Technology described the intensification of energy problems, environment problems, and the near future measures to be taken against these problems. The lecture titled 'summarization of the achievements in development of load leveling air conditioning technologies utilizing unutilized energies at high levels' given by Professor Nakahara at the Kanagawa University explained the summary of the achievements in research and development by themes. (NEDO)

  13. Reflections about the cogeneration of electrical and thermal energy in conditions of Chisinau city, Republic of Moldova

    International Nuclear Information System (INIS)

    Musteata, Valentin

    2004-01-01

    The cogeneration of electrical and thermal energy in Chisinau city is implements on heat power plants HPP-1 and HPP - 2. The district heating, receiving thermal energy from these power plants, has a severe alternative from the autonomous heating system. The capabilities of reducing the cost of thermal energy produced by HPP-2 are analyzed and the paths of improvement of district heating are forecasted. (author)

  14. Energy

    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)

  15. Energy

    OpenAIRE

    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....

  16. Development of the advanced load leveling air conditioning technology utilizing unutilized energy; Miriyo energy kodo katsuyo fuka heijunka reidanbo gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    A heat supply plant utilizing unutilized energy is called for environment-friendly efficient operation including stable heat supply, energy saving, CO{sub 2} emission control and power load leveling. Toshiba developed the optimum operation system for environment-friendly efficient operation considering heat demand prediction and characteristics of a heat supply plant. The demonstration test result showed that this system is effective to reduce power cost of a heat supply plant by nearly 15%. This system was promoted by joint research of NEDO, Heat Pump and Thermal Storage Technology Center of Japan and Toshiba supported by Agency of Natural Resources and Energy, MITI. (translated by NEDO)

  17. Energies

    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.)

  18. Life-Cycle Energy Use and Greenhouse Gas Emissions Analysis for Bio-Liquid Jet Fuel from Open Pond-Based Micro-Algae under China Conditions

    Directory of Open Access Journals (Sweden)

    Xiliang Zhang

    2013-09-01

    Full Text Available A life-cycle analysis (LCA of greenhouse gas (GHG emissions and energy use was performed to study bio-jet fuel (BJF production from micro-algae grown in open ponds under Chinese conditions using the Tsinghua University LCA Model (TLCAM. Attention was paid to energy recovery through biogas production and cogeneration of heat and power (CHP from the residual biomass after oil extraction, including fugitive methane (CH4 emissions during the production of biogas and nitrous oxide (N2O emissions during the use of digestate (solid residue from anaerobic digestion as agricultural fertilizer. Analyses were performed based on examination of process parameters, mass balance conditions, material requirement, energy consumptions and the realities of energy supply and transport in China (i.e., electricity generation and heat supply primarily based on coal, multiple transport modes. Our LCA result of the BJF pathway showed that, compared with the traditional petrochemical pathway, this new pathway will increase the overall fossil energy use and carbon emission by 39% and 70%, respectively, while decrease petroleum consumption by about 84%, based on the same units of energy service. Moreover, the energy conservation and emission reduction benefit of this new pathway may be accomplished by two sets of approaches: wider adoption of low-carbon process fuels and optimization of algae cultivation and harvest, and oil extraction processes.

  19. The Behavior of Hydrogen Under Extreme Conditions on Ultrafast Timescales (A 'Life at the Frontiers of Energy Research' contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)

    International Nuclear Information System (INIS)

    Mao, Ho-kwang

    2011-01-01

    'The Behavior of Hydrogen Under Extreme Conditions on Ultrafast Timescales ' was submitted by the Center for Energy Frontier Research in Extreme Environments (EFree) to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. EFree is directed by Ho-kwang Mao at the Carnegie Institute of Washington and is a partnership of scientists from thirteen institutions.The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of Energy Frontier Research in Extreme Environments is 'to accelerate the discovery and creation of energy-relevant materials using extreme pressures and temperatures.' Research topics are: catalysis (CO 2 , water), photocatalysis, solid state lighting, optics, thermelectric, phonons, thermal conductivity, solar electrodes, fuel cells, superconductivity, extreme environment, radiation effects, defects, spin dynamics, CO 2 (capture, convert, store), greenhouse gas, hydrogen (fuel, storage), ultrafast physics, novel materials synthesis, and defect tolerant materials.

  20. ENERGY STAR® Retail Products Platform (RPP): Conditions and Considerations in Evaluating Market Transformation Programs and Evaluation Guidance for RPP

    Energy Technology Data Exchange (ETDEWEB)

    Li, Michael [U.S. Department of Energy; Banwell, Peter [U.S. Environmental Protection Agency

    2018-01-09

    The purpose of this guide is to provide a resource for state utility regulators, utilities, the evaluation community and regulatory stakeholders on methods to measure energy savings from the ENERGY STAR Retail Products Platform (link is external). The guidelines outlined in this document were developed by evaluation experts.

  1. A statistical adjustment approach for climate projections of snow conditions in mountain regions using energy balance land surface models

    Science.gov (United States)

    Verfaillie, Deborah; Déqué, Michel; Morin, Samuel; Lafaysse, Matthieu

    2017-04-01

    Projections of future climate change have been increasingly called for lately, as the reality of climate change has been gradually accepted and societies and governments have started to plan upcoming mitigation and adaptation policies. In mountain regions such as the Alps or the Pyrenees, where winter tourism and hydropower production are large contributors to the regional revenue, particular attention is brought to current and future snow availability. The question of the vulnerability of mountain ecosystems as well as the occurrence of climate-related hazards such as avalanches and debris-flows is also under consideration. In order to generate projections of snow conditions, however, downscaling global climate models (GCMs) by using regional climate models (RCMs) is not sufficient to capture the fine-scale processes and thresholds at play. In particular, the altitudinal resolution matters, since the phase of precipitation is mainly controlled by the temperature which is altitude-dependent. Simulations from GCMs and RCMs moreover suffer from biases compared to local observations, due to their rather coarse spatial and altitudinal resolution, and often provide outputs at too coarse time resolution to drive impact models. RCM simulations must therefore be adjusted using empirical-statistical downscaling and error correction methods, before they can be used to drive specific models such as energy balance land surface models. In this study, time series of hourly temperature, precipitation, wind speed, humidity, and short- and longwave radiation were generated over the Pyrenees and the French Alps for the period 1950-2100, by using a new approach (named ADAMONT for ADjustment of RCM outputs to MOuNTain regions) based on quantile mapping applied to daily data, followed by time disaggregation accounting for weather patterns selection. We first introduce a thorough evaluation of the method using using model runs from the ALADIN RCM driven by a global reanalysis over the

  2. Modeling and numerical simulation of a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage

    Institute of Scientific and Technical Information of China (English)

    QIU Jia; LIANG Jian; CHEN GuangMing; DU RuXu

    2009-01-01

    This paper presents a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage. It solves the problem of unreliable solar energy supply by storing the working fluids and hence, functions 24 h per day. First, the working principles are described and the dynamic models for the primary energy storage components are developed. Then, the system is evaluated based on a numerical simulation. Based on the meteorological data of a typical day in a subtropical area, with the area of a solar collector being set at 19.15 m2, whilst the initial charging mass, mass fraction and temperature of the solution are respectively set at 379.5 kg, 54.16% and 34.5 ℃, it is found that the respective coefficients of performance (COP) of the air conditioning system and the en-tire system (including the solar panel) are 0.7771 and 0.4372. In particular, the energy storage density of the system is 206.69 MJ/m3 which is much greater than those of chilled water or hot water storage systems under comparable conditions. This makes the new system much more compact and efficient. Finally, an automatic control strategy is given to achieve the highest COP when solar energy fluctuates.

  3. Development of a Performance Analysis Code for the Off-design conditions of a S-CO2 Brayton Cycle Energy Conversion System

    International Nuclear Information System (INIS)

    Yoo, Yong-Hwan; Cha, Jae-Eun; Lee, Tae-Ho; Eoh, Jae-Hyuk; Kim, Seong-O

    2008-01-01

    For the development of a supercritical carbon dioxide (S-CO2) Brayton cycle energy conversion system coupled to KALIMER-600, a thermal balance has been established on 100% power operating conditions including all the reactor system models such as a primary heat transport system (PHTS), an intermediate heat transport system (IHTS), and an energy conversion system. The S-CO2 Brayton cycle energy conversion system consists of a sodium-CO2 heat exchanger (Hx), turbine, high temperature recuperate (HTR), low temperature recuperate (LTR), precooler, compressor no.1, and compressor no.2. Two compressors were employed to avoid a sharp change of the physical properties near their critical point with a corresponding pressure. The component locations and their operating conditions are illustrated. Energy balance of the power conversion system in KALIMER-600 was designed with the full power condition of each component. Therefore, to predict the off-design conditions and to evaluate each component, an off-design performance analysis code should be accomplished. An off-design performance analysis could be classified into overall system control logic and local system control logic. The former means that mass flow rate and power are controlled by valves, and the latter implies that a bypass or inventory control is an admitted system balance. The ultimate goal of this study is development of the overall system control logic

  4. Examination of the conditions of a broadening of the general tax for polluting activities to the intermediate energy consumptions. Incentive mechanisms for the abatement of greenhouse gas emissions

    International Nuclear Information System (INIS)

    Bureau, D.

    2000-05-01

    Among the various existing incentive mechanisms for the abatement of greenhouse gas emissions, like the pollution regulations and the financial help for energy mastery, this document analyzes the conditions of efficiency of the negotiated voluntary agreements and of the tradable emission quotas and their articulation with the fiscality. (J.S.)

  5. Energy wood reserves and the utilisation conditions of them 1/1994 - 4/1997; Energiapuuvarat ja niiden hyoedyntaeminen

    Energy Technology Data Exchange (ETDEWEB)

    Keskimoeloe, A [Metsaetalouden Kehittaemiskeskus Tapio, Helsinki (Finland)

    1997-12-01

    The objective of the D105 project was to reduce the harvesting and procurement costs of energy wood by developing a model for establishing the procurable volumes of energy wood. This will be done by using forestry planning data on private forests and numeric road data. Position data (GRASS) and database (Ms Access) programs are used in the model. The project was launched in the beginning of 1994 and will run until April 1997. Basic information needed was collected from pilot areas in co-operation with the PUUHA project launched in Mikkeli. Later the work continued with the Forest Energy Project of Central Finland. The position-data program is used to produce forest and road haulage distances for each forest figure. The distance data is then transferred to the database program. In the database program the procurement costs of energy wood are established by using cost models based on productivity curves. After that, it is possible to establish if the figure is economically worthwhile for energy wood harvesting purposes or not. By using this information, the model calculates first the amount of energy wood on the figure and secondly the procurable volumes of energy wood that can be delivered to the local heating plant. (orig.)

  6. How does Germany's green energy policy affect electricity market volatility? An application of conditional autoregressive range models

    International Nuclear Information System (INIS)

    Auer, Benjamin R.

    2016-01-01

    Based on a dynamic model for the high/low range of electricity prices, this article analyses the effects of Germany's green energy policy on the volatility of the electricity market. Using European Energy Exchange data from 2000 to 2015, we find rather high volatility in the years 2000–2009 but also that the weekly price range has significantly declined in the period following the year 2009. This period is characterised by active regulation under the Energy Industry Law (EnWG), the EU Emissions Trading Directive (ETD) and the Renewable Energy Law (EEG). In contrast to the preceding period, price jumps are smaller and less frequent (especially for day-time hours), implying that current policy measures are effective in promoting renewable energies while simultaneously upholding electricity market stability. This is because the regulations strive towards a more and more flexible and market-oriented structure which allows better integration of renewable energies and supports an efficient alignment of renewable electricity supply with demand. - Highlights: • We estimate a CARR model for German electricity price data. • We augment the model by dummies capturing important regulations. • We find a significant decline in the price range after the year 2009. • This implies effective price stabilisation by German energy policy.

  7. Monte Carlo calculation of energy loss of hydrogen and helium ions transmitted under channelling conditions in silicon single crystal

    International Nuclear Information System (INIS)

    El Bounagui, O.; Erramli, H.

    2010-01-01

    In this work, we report on calculations of the electronic channelling energy loss of hydrogen and helium ions along Si and Si axial directions for the low energy range by using the Monte Carlo simulation code. Simulated and experimental data are compared for protons and He ions in the and axis of silicon. A reasonable agreement was found. Computer simulation was also employed to study the angular dependence of energy loss for 0.5, 0.8, 1, and 2 MeV channelled 4 He ions transmitted through a silicon crystal of 3 μm thickness along the axis.

  8. Optimum Operating Conditions of (PbxX1−x(ZryTizY1−y−z Piezoelectric Transducer for Vibrational Energy Harvesting Applications

    Directory of Open Access Journals (Sweden)

    Funda Demir

    2016-01-01

    Full Text Available The electrical energy production capability of bimorph (PbxX1-x(ZryTizY1-y-z fiber composite piezoelectric transducer has been investigated for energy harvesting applications. The material has been analyzed under different frequencies, bending amounts, and temperatures. The operating conditions for maximum electrical energy outcome have been determined. The natural frequencies of oscillations in the macro dimensions have been found to be inversely proportional to the length of the material. On the other hand, the voltage output with respect to the oscillation frequency exhibits an interesting behavior such that the characteristic curve shifts to higher frequencies as the bending radius is decreased. This behavior has been interpreted as a result of possible overtone transitions of the oscillations to a stiffer mode. The increasing temperature has been observed to have a negative effect on the piezoelectric energy harvesting property. When the determined optimum conditions were utilized, the amount of electrical energy stored in 6300 s by an energy harvester circuitry has been found to be 0.8 J.

  9. An Environmental Analysis of the Effect of Energy Saving, Production and Recovery Measures on Water Supply Systems under Scarcity Conditions

    Directory of Open Access Journals (Sweden)

    Valeria Puleo

    2015-06-01

    Full Text Available Water is one of the primary resources provided for maintaining quality of life and social status in urban areas. As potable water is considered to be a primary need, water service has usually been managed without examining the economic and environmental sustainability of supply processes. Currently, due to increases in energy costs and the growth of environment preservation policies, reducing water leakage, energy consumption and greenhouse gas (GHG production have become primary objectives in reducing the environmental footprint of water service. The present paper suggests the implementation of some performance indicators that show the interdependence of water loss, energy consumption and GHG emission. These indicators are used to compare a few possible mitigation scenarios involving water loss reduction and increasing the system’s energy efficiency. The proposed indicators were applied to a complex urban water supply system serving the city of Palermo (Italy.

  10. Builder System Performance Package Targeting 30% - 40% Savings in Space Conditioning Energy Use: December 2002 - December 2003

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-06-01

    The Consortium for Advanced Residential Building (CARB) describes recommended best practices to achieve 30% - 40% energy savings without compromising health or safety in houses built in cold climates, hot-humid climates, and hot-dry climates.

  11. The Potential and Utilization of Unused Energy Sources for Large-Scale Horticulture Facility Applications under Korean Climatic Conditions

    Directory of Open Access Journals (Sweden)

    In Tak Hyun

    2014-07-01

    Full Text Available As the use of fossil fuel has increased, not only in construction, but also in agriculture due to the drastic industrial development in recent times, the problems of heating costs and global warming are getting worse. Therefore, introduction of more reliable and environmentally-friendly alternative energy sources has become urgent and the same trend is found in large-scale horticulture facilities. In this study, among many alternative energy sources, we investigated the reserves and the potential of various different unused energy sources which have infinite potential, but are nowadays wasted due to limitations in their utilization. In addition, we utilized available unused energy as a heat source for a heat pump in a large-scale horticulture facility and analyzed its feasibility through EnergyPlus simulation modeling. Accordingly, the discharge flow rate from the Fan Coil Unit (FCU in the horticulture facility, the discharge air temperature, and the return temperature were analyzed. The performance and heat consumption of each heat source were compared with those of conventional boilers. The result showed that the power load of the heat pump was decreased and thus the heat efficiency was increased as the temperature of the heat source was increased. Among the analyzed heat sources, power plant waste heat which had the highest heat source temperature consumed the least electric energy and showed the highest efficiency.

  12. Energy efficient of the residential buildings based climatic condition using experimental design: a case study in malaysia

    Directory of Open Access Journals (Sweden)

    Zahraee Seyed Mojib

    2017-01-01

    Full Text Available In recent years, energy consumption has become a critical issue in the developed and developing countries. Residential buildings are one of the most users of energy in the construction sector that use the highest share of energy. This paper aims at evaluating the effect of four factors that are temperature, humidity, airflow and pressure on the cooling load in the residential buildings. To achieve this goal, statistical experimental design is used to determine the optimum setting of factors that result in optimum energy usage. Simulation software and energy analysis is used to simulate a two-storey building in Malaysia as the case of study. Final results showed that the temperature, humidity and interaction between them have the most significant effect on the energy cooling load. Moreover, to obtain the minimum value of cooling load the temperature and humidity should be equal to A=20 Celsius degree and B=60% respectively. In addition, the other two insignificant factors, airflow and pressure should be placed at the high level which are equal to C=3 cubic meters per hour, and D=6 Pascal (P respectively.

  13. Smart electricity metering as an energy efficiency instrument: Comparative analyses of regulation and market conditions in Europe. Volume 1

    International Nuclear Information System (INIS)

    Morch, Andrei Z.; Parsons, John; Kester, Josco C.P.

    2007-01-01

    The new European Directive on Energy End-use Efficiency and Energy Services (ESD) (EC 2006/32, 2006) states the importance of installing metering and billing systems allowing consumers to regulate and steer their consumption. Extra information provided by these 'Smart Meters', is proposed as an important technological innovation to improve energy efficiency. In the next few years the European energy markets will face a challenging task - implementation of Smart Metering systems for small and middle-size customers. The public policies and implementation paths of Smart Metering today vary across Europe from full-scale implementation to very limited. Implementation of Smart Metering systems provides a technological basis, which makes it possible to implement new market-based products and services encouraging the Final Customers to save energy. Electricity suppliers and Distribution System Operators play a key role in a full utilisation of the energy saving potential from Smart Metering, but need a benefit for doing this. These new market opportunities could provide this benefit

  14. Pointwise estimates of pseudo-differential operators

    DEFF Research Database (Denmark)

    Johnsen, Jon

    As a new technique it is shown how general pseudo-differential operators can be estimated at arbitrary points in Euclidean space when acting on functions u with compact spectra.The estimate is a factorisation inequality, in which one factor is the Peetre–Fefferman–Stein maximal function of u......, whilst the other is a symbol factor carrying the whole information on the symbol. The symbol factor is estimated in terms of the spectral radius of u, so that the framework is well suited for Littlewood–Paley analysis. It is also shown how it gives easy access to results on polynomial bounds...... and estimates in Lp , including a new result for type 1,1-operators that they are always bounded on Lp -functions with compact spectra....

  15. Pointwise estimates of pseudo-differential operators

    DEFF Research Database (Denmark)

    Johnsen, Jon

    2011-01-01

    As a new technique it is shown how general pseudo-differential operators can be estimated at arbitrary points in Euclidean space when acting on functions u with compact spectra. The estimate is a factorisation inequality, in which one factor is the Peetre–Fefferman–Stein maximal function of u......, whilst the other is a symbol factor carrying the whole information on the symbol. The symbol factor is estimated in terms of the spectral radius of u, so that the framework is well suited for Littlewood–Paley analysis. It is also shown how it gives easy access to results on polynomial bounds...... and estimates in Lp, including a new result for type 1, 1-operators that they are always bounded on Lp-functions with compact spectra....

  16. Pointwise extensions of GSOS-defined operations

    NARCIS (Netherlands)

    Hansen, H.H.; Klin, B.

    2011-01-01

    Final coalgebras capture system behaviours such as streams, infinite trees and processes. Algebraic operations on a final coalgebra can be defined by distributive laws (of a syntax functor S over a behaviour functor F). Such distributive laws correspond to abstract specification formats. One such

  17. Pointwise Extensions of GSOS-Defined Operations

    NARCIS (Netherlands)

    H.H. Hansen (Helle); B. Klin

    2011-01-01

    textabstractFinal coalgebras capture system behaviours such as streams, infinite trees and processes. Algebraic operations on a final coalgebra can be defined by distributive laws (of a syntax functor $\\FSig$ over a behaviour functor $F$). Such distributive laws correspond to abstract specification

  18. Analysis of energy efficiency retrofit schemes for heating, ventilating and air-conditioning systems in existing office buildings based on the modified bin method

    International Nuclear Information System (INIS)

    Wang, Zhaoxia; Ding, Yan; Geng, Geng; Zhu, Neng

    2014-01-01

    Highlights: • A modified bin method is adopted to propose and optimize the EER schemes. • A case study is presented to demonstrate the analysis procedures of EER schemes. • Pertinent EER schemes for HVAC systems are proposed for the object building. - Abstract: Poor thermal performance of building envelop and low efficiencies of heating, ventilating and air-conditioning (HVAC) systems can always be found in the existing office buildings with large energy consumption. This paper adopted a modified bin method to propose and optimize the energy efficiency retrofit (EER) schemes. An existing office building in Tianjin was selected as an example to demonstrate the procedures of formulating the design scheme. Pertinent retrofit schemes for HVAC system were proposed after the retrofit of building envelop. With comprehensive consideration of energy efficiency and economic benefits, the recommended scheme that could improve the overall energy efficiency by 71.20% was determined

  19. Energy efficiency and comfort conditions in passive solar buildings: Effect of thermal mass at equatorial high altitudes

    Science.gov (United States)

    Ogoli, David Mwale

    This dissertation is based on the philosophy that architectural design should not just be a function of aesthetics, but also of energy-efficiency, advanced technologies and passive solar strategies. A lot of published literature is silent regarding buildings in equatorial highland regions. This dissertation is part of the body of knowledge that attempts to provide a study of energy in buildings using thermal mass. The objectives were to establish (1) effect of equatorial high-altitude climate on thermal mass, (2) effect of thermal mass on moderating indoor temperatures, (3) effect of thermal mass in reducing heating and cooling energy, and (4) the amount of time lag and decrement factor of thermal mass. Evidence to analyze the effect of thermal mass issues came from three sources. First, experimental physical models involving four houses were parametrically conducted in Nairobi, Kenya. Second, energy computations were made using variations in thermal mass for determining annual energy usage and costs. Third, the data gathered were observed, evaluated, and compared with currently published research. The findings showed that: (1) Equatorial high-altitude climates that have diurnal temperature ranging about 10--15°C allow thermal mass to moderate indoor temperatures; (2) Several equations were established that indicate that indoor mean radiant temperatures can be predicted from outdoor temperatures; (3) Thermal mass can reduce annual energy for heating and cooling by about 71%; (4) Time lag and decrement of 200mm thick stone and concrete thermal mass can be predicted by a new formula; (5) All windows on a building should be shaded. East and west windows when shaded save 51% of the cooling energy. North and south windows when fully shaded account for a further 26% of the cooling energy; (6) Insulation on the outside of a wall reduces energy use by about 19.6% below the levels with insulation on the inside. The basic premise of this dissertation is that decisions that

  20. Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin-layer drying of berberis fruit (Berberidaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Aghbashlo, Mortaza; Kianmehr, Mohammad H.; Samimi-Akhijahani, Hadi [Department of Agriculture Machinery, University of Tehran, Aboreyhan Campus (Iran)

    2008-10-15

    Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in medicine to cure liver, neck and stomach cancer, blood purification and mouth scent. Dried berberis fruit using new technology was preserved for relatively long time. Thin-layer drying simulation was used to obtain experiment data, using laboratory scale hot-air dryer of the static tray. Fick's second law was used as a major equation to calculate the moisture diffusivity with some simplification. The calculated value of moisture diffusivity varied from a minimum of 3.320 x 10{sup -10} to a maximum of 9 x 10{sup -9} m{sup 2}/s and the value of energy activation from a minimum of 110.837 to a maximum of 130.61 kJ/mol of from 50 C to 70 C with drying air velocities of 0.5-2 m/s. The high value of the energy of activation for berberis fruit probably related to the tissue of berberis fruit and high moisture content (about 74.28%w.b), and intensive changes in D{sub eff} values for a different air temperature at constant air velocity. The input energy values and specific energy requirement for thin-drying of berberis fruit were found to be in the range of 0.643348-35.20032 (kWh) and 20.9355-1110.0700 (kWh/kg) from 50 C to 70 C with drying air velocities of 0.5-2 m/s, respectively. (author)

  1. Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin-layer drying of berberis fruit (Berberidaceae)

    International Nuclear Information System (INIS)

    Aghbashlo, Mortaza; Kianmehr, Mohammad H.; Samimi-Akhijahani, Hadi

    2008-01-01

    Berberis is known as a medicinal and ornamental plant in the world. Berberis fruit is used in medicine to cure liver, neck and stomach cancer, blood purification and mouth scent. Dried berberis fruit using new technology was preserved for relatively long time. Thin-layer drying simulation was used to obtain experiment data, using laboratory scale hot-air dryer of the static tray. Fick's second law was used as a major equation to calculate the moisture diffusivity with some simplification. The calculated value of moisture diffusivity varied from a minimum of 3.320 x 10 -10 to a maximum of 9 x 10 -9 m 2 /s and the value of energy activation from a minimum of 110.837 to a maximum of 130.61 kJ/mol of from 50 deg. C to 70 deg. C with drying air velocities of 0.5-2 m/s. The high value of the energy of activation for berberis fruit probably related to the tissue of berberis fruit and high moisture content (about 74.28%w.b), and intensive changes in D eff values for a different air temperature at constant air velocity. The input energy values and specific energy requirement for thin-drying of berberis fruit were found to be in the range of 0.643348-35.20032 (kWh) and 20.9355-1110.0700 (kWh/kg) from 50 deg. C to 70 deg. C with drying air velocities of 0.5-2 m/s, respectively

  2. Experimental analysis of energy absorption behaviour of Al-tube filled with pumice lightweight concrete under axial loading condition

    Science.gov (United States)

    Rajak, D. K.; Deshpande, P. G.; Kumaraswamidhas, L. A.

    2017-08-01

    This Paper aimed at experimental investigation of compressive behaviour of square tube filled with pumice lightweight concrete (PLC). Square section of 20×20×30 mm is investigated, which is the backbone structure. The compression deformation result shows the better folding mechanism, displacement value, and energy absorption. PLC concrete filled with aluminium thin-wall tubes has been revealed superior energy absorption capacity (EAC) under low strain rate at room temperature. Superior EAC resulted as a result of mutual deformation benefit between aluminium section and PLC is also analysed. PLC was characterised by Fourier Transform Infrared (FTIR) and Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-ray Spectrometry (EDX) analysis for better understanding of material behaviour. Individual and comparative load bearing graphs is logged for better prospective of analysing. Novel approach aimed at validation of porous lightweight concrete for better lightweight EA filler material.

  3. A general approach for defining the macroscopic free energy density of saturated porous media at finite strains under non-isothermal conditions

    International Nuclear Information System (INIS)

    Gajo, A.

    2011-01-01

    A general approach is proposed for defining the macroscopic free energy density function (and its complement, the free enthalpy) of a saturated porous medium submitted to finite deformations under non-isothermal conditions, in the case of compressible fluid and solid constituents. Reference is made to an elementary volume treated as an 'open system', moving with the solid skeleton. The proposed free energy depends on the generalised strains (namely an appropriate measure of the strain of the solid skeleton and the variation in fluid mass content) and the absolute temperatures of the solid and fluid phases (which are assumed to differ from each other for the sake of generality). This macroscopic energy proves to be a potential for the generalised stresses (namely the associated measure of the total stress and the free enthalpy of the pore fluid per unit mass) and the entropies of the solid and fluid phases. In contrast with mixture theories, the resulting free energy is not the simple sum of the free energies of the single constituents. Two simplified cases are examined in detail, i.e. the semi-linear theory (originally proposed for isothermal conditions and extended here to non-isothermal problems) and the linear theory. The proposed approach paves the way to the consistent non-isothermal-hyper-elastic-plastic modelling of saturated porous media with a compressible fluid and solid constituents. (authors)

  4. Impacts of city-block-scale countermeasures against urban heat-island phenomena upon a building's energy-consumption for air-conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kikegawa, Yukihiro [Department of Environmental Systems, Meisei University, 2-1-1 Hodokubo, Hino-shi, Tokyo 191-8506 (Japan); Genchi, Yutaka [Research Center for Life Cycle Assessment, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Kondo, Hiroaki [Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Hanaki, Keisuke [Department of Urban Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2006-06-15

    This study quantifies the possible impacts of urban heat-island countermeasures upon buildings' energy use during summer in Tokyo metropolis. Considering the dependency of the buildings air temperature upon the local urban canopy structure, Tokyo urban canopies were classified in the city-block-scale using the sky-view factor (svf). Then, a multi-scale model system describing the interaction between buildings' energy use and urban meteorological conditions was applied to each classified canopy. In terms of urban warming alleviation and cooling energy saving, simulations suggested that the reduction in the air-conditioning anthropogenic heat could be the most effective measure in office buildings' canopies, and that vegetative fraction increase on the side walls of buildings in residential canopies. Both measures indicated daily and spatially averaged decreases in near-ground summer air temperature of 0.2-1.2{sup o}C. The simulations also suggested these temperature decreases could result in the buildings' cooling energy-savings of 4-40%, indicating remarkable savings in residential canopies. These temperature drops and energy savings tended to increase with the decrease of the svf of urban canopies. (author)

  5. Daylighting for energy conservation in an existing building under tropical climate conditions: a case study of Lai Sue Thai building Ramkhamhaeng University

    Directory of Open Access Journals (Sweden)

    Lerdlekha Tanachaikhan

    2015-12-01

    Full Text Available Daylighting using skylight has been shown to have a high potential in reducing electrical lighting energy, and could provide a more pleasant atmosphere of a daylit space. However, in hot climates, the main constraint of daylighting is the solar heat gain that contributes to major heat load for an air-conditioning system. If the balance between the beneficial light gain used to offset lighting energy requirement and heat gain from daylight is well considered, significant energy savings can be obtained. The main objective of the study is to evaluate the potential of daylighting for energy conservation in the tropics through theoretical analysis (simulation study and experimental observation. Lai Sue Thai Building (an existing and educational building located at Ramkhamkaeng University was selected as a case study. From analysis, use of daylight could reduce electrical energy in this building by up to 76% compared to the initial condition where fully lighting was supplied. Window orientation would also play an important role. Moreover, heat gain through windows due to daylighting can be controlled by overhangs and the appropriate Window-to-Wall ratio that would be about 30% for this building. An experimental study was also carried out to validate the results in a selected room. About 49% and 37% of Relative Root Mean Square Error (RRMSE were observed in light and heat measurements, respectively

  6. How organizational and global factors condition the effects of energy efficiency on CO_2 emission rebounds among the world's power plants

    International Nuclear Information System (INIS)

    Grant, Don; Jorgenson, Andrew K.; Longhofer, Wesley

    2016-01-01

    The United Nations Intergovernmental Panel on Climate Change (IPCC), the International Energy Agency (IEA), and several nations suggest that energy efficiency is an effective strategy for reducing energy consumption and associated greenhouse gas emissions. Skeptics contend that because efficiency lowers the price of energy and energy services, it may actually increase demand for them, causing total emissions to rise. While both sides of this debate have researched the magnitude of these so-called rebound effects among end-use consumers, researchers have paid less attention to the conditions under which direct rebounds cause CO_2 emissions to rise among industrial producers. In particular, researchers have yet to explore how organizational and global factors might condition the effects of efficiency on emissions among power plants, the world's most concentrated sources of anthropogenic greenhouse gases. Here we use a unique dataset containing nearly every fossil-fuel power plant in the world to determine whether the impact of efficiency on emissions varies by plants' age, size, and location in global economic and normative systems. Findings reveal that each of these factors has a significant interaction with efficiency and thus shapes environmentally destructive rebound effects. - Highlights: •Skeptics charge that energy efficiency may actually cause CO_2 emissions to rise. •Few have examined whether such rebound effects occur among power plants. •Little also known about whether plants' organizational and global characteristics condition rebounds. •Conduct first analysis of rebound effects among the world's power plants. •Rebounds found to depend on plants' age, size, and location in international economic and normative systems.

  7. Optimal replacement of residential air conditioning equipment to minimize energy, greenhouse gas emissions, and consumer cost in the US

    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.

  8. The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions

    Directory of Open Access Journals (Sweden)

    C. G. Menéndez

    1999-11-01

    Full Text Available The effect of sea-ice on various aspects of the Southern Hemisphere (SH extratropical climate is examined. Two simulations using the LMD GCM are performed: a control run with the observed sea-ice distribution and an anomaly run in which all SH sea-ice is replaced by open ocean. When sea-ice is removed, the mean sea level pressure displays anomalies predominantly negatives near the Antarctic coast. In general, the meridional temperature gradient is reduced over most of the Southern Ocean, the polar jet is weaker and the sea level pressure rises equatorward of the control ice edge. The high frequency filtered standard deviation of both the sea level pressure and the 300-hPa geopotential height decreases over the southern Pacific and southwestern Atlantic oceans, especially to the north of the ice edge (as prescribed in the control. In contrast, over the Indian Ocean the perturbed simulation exhibits less variability equatorward of about 50°S and increased variability to the south. The zonal averages of the zonal and eddy potential and kinetic energies were evaluated. The effect of removing sea-ice is to diminish the available potential energy of the mean zonal flow, the available potential energy of the perturbations, the kinetic energy of the growing disturbances and the kinetic energy of the mean zonal flow over most of the Southern Ocean. The zonally averaged intensity of the subpolar trough and the rate of the baroclinic energy conversions are also weaker.Key words. Air-sea interactions · Meteorology and atmospheric dynamics (climatology; ocean · atmosphere interactions

  9. The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions

    Directory of Open Access Journals (Sweden)

    C. G. Menéndez

    Full Text Available The effect of sea-ice on various aspects of the Southern Hemisphere (SH extratropical climate is examined. Two simulations using the LMD GCM are performed: a control run with the observed sea-ice distribution and an anomaly run in which all SH sea-ice is replaced by open ocean. When sea-ice is removed, the mean sea level pressure displays anomalies predominantly negatives near the Antarctic coast. In general, the meridional temperature gradient is reduced over most of the Southern Ocean, the polar jet is weaker and the sea level pressure rises equatorward of the control ice edge. The high frequency filtered standard deviation of both the sea level pressure and the 300-hPa geopotential height decreases over the southern Pacific and southwestern Atlantic oceans, especially to the north of the ice edge (as prescribed in the control. In contrast, over the Indian Ocean the perturbed simulation exhibits less variability equatorward of about 50°S and increased variability to the south. The zonal averages of the zonal and eddy potential and kinetic energies were evaluated. The effect of removing sea-ice is to diminish the available potential energy of the mean zonal flow, the available potential energy of the perturbations, the kinetic energy of the growing disturbances and the kinetic energy of the mean zonal flow over most of the Southern Ocean. The zonally averaged intensity of the subpolar trough and the rate of the baroclinic energy conversions are also weaker.

    Key words. Air-sea interactions · Meteorology and atmospheric dynamics (climatology; ocean · atmosphere interactions

  10. Sable Offshore Energy Inc.: Response to 'The Canada-Nova Scotia Offshore Petroleum Board Benefits Plan Decision Report' Condition No. 3: Employment and Training Plan; Condition No. 4: Research and Development Plan; Condition No. 6: Disadvantaged Individual or Groups; Condition No. 7: Technology Transfer

    International Nuclear Information System (INIS)

    1998-01-01

    Decisions of the Canada-Nova Scotia Offshore Petroleum Board, regarding the responses of Sable Offshore Energy Inc (SOEI) to conditions imposed by the Board in the Sable Offshore Energy Project Canada-Nova Scotia Benefit Plan Decision Report, have been announced. According to the press release (copy attached), the Board accepted the responses of SOEI regarding the establishment and staffing of an office in Nova Scotia for the implementation and project management and training of project personnel, the level of expenditures for research and development to be undertaken in Nova Scotia, proposed initiatives for employment and training opportunities for disadvantaged individuals and groups, and a technology transfer plan that will facilitate succession planning and create joint venturing opportunities for Nova Scotian and Canadian industry. tabs., figs

  11. Deregulation of the energy industry in the United States : access conditions to the American market and business opportunities

    International Nuclear Information System (INIS)

    Marcoux, D.

    1998-01-01

    The impact of deregulation in the North American electricity market on the energy industry in Quebec was discussed. Increased competition, a direct result of deregulation, can lead to open markets for Quebec utilities. It is expected that Quebec utilities such as Hydro-Quebec and Gaz-Metropolitain will profit from an open market since consumers will have the choice of electricity suppliers that will best suit their needs. Open markets enabling Hydro-Quebec to sell at market prices in the American market present tremendous opportunities for Quebec utilities, especially in view of the lower production costs, the accumulated knowledge about energy markets, and their aggressive policy to form constructive partnerships.. Figs

  12. Increased air temperature during simulated autumn conditions does not increase photosynthetic carbon gain but affects the dissipation of excess energy in seedlings of the evergreen conifer Jack pine.

    Science.gov (United States)

    Busch, Florian; Hüner, Norman P A; Ensminger, Ingo

    2007-03-01

    Temperature and daylength act as environmental signals that determine the length of the growing season in boreal evergreen conifers. Climate change might affect the seasonal development of these trees, as they will experience naturally decreasing daylength during autumn, while at the same time warmer air temperature will maintain photosynthesis and respiration. We characterized the down-regulation of photosynthetic gas exchange and the mechanisms involved in the dissipation of energy in Jack pine (Pinus banksiana) in controlled environments during a simulated summer-autumn transition under natural conditions and conditions with altered air temperature and photoperiod. Using a factorial design, we dissected the effects of daylength and temperature. Control plants were grown at either warm summer conditions with 16-h photoperiod and 22 degrees C or conditions representing a cool autumn with 8 h/7 degrees C. To assess the impact of photoperiod and temperature on photosynthesis and energy dissipation, plants were also grown under either cold summer (16-h photoperiod/7 degrees C) or warm autumn conditions (8-h photoperiod/22 degrees C). Photosynthetic gas exchange was affected by both daylength and temperature. Assimilation and respiration rates under warm autumn conditions were only about one-half of the summer values but were similar to values obtained for cold summer and natural autumn treatments. In contrast, photosynthetic efficiency was largely determined by temperature but not by daylength. Plants of different treatments followed different strategies for dissipating excess energy. Whereas in the warm summer treatment safe dissipation of excess energy was facilitated via zeaxanthin, in all other treatments dissipation of excess energy was facilitated predominantly via increased aggregation of the light-harvesting complex of photosystem II. These differences were accompanied by a lower deepoxidation state and larger amounts of beta-carotene in the warm autumn

  13. Accuracy of the Temperature-Vegetation Dryness Index using MODIS under water-limited vs. energy-limited evapotranspiration conditions

    DEFF Research Database (Denmark)

    Garcia, Monica; Fernández, N.; Villagarcía, L.

    2014-01-01

    surface fluxes using MODIS data; and (ii) provide insights about the factors most affecting the accuracy of results. Factors considered included the type of climatic control on evapotranspiration, λE, (i.e. water-limited vs. energy-limited), the quality of Tair estimates, the heterogeneity of land cover...

  14. Evaluation of the solar conditions for the acquisitions of energy from renewable sources on the base of Sosnowiec city (Poland)

    Science.gov (United States)

    Sarapata, Sonia

    2014-09-01

    The country's energy security risk, as well as a desire to protect the environment from the pollution and degradation which are the results of conventional fuels acquisition - these was a motivation for intensive researches on the use of renewable energy sources in eco - innovative installations. Solar radiation is one of the self - renewable energy sources which can be used both as a source of electricity and heat. The area of research is Sosnowiec city located in the south of Poland in the eastern part of Silesia voivodeship. The solar radiation data covering the years 2003 to 2013 was used. The intra - annual variability of daily averaged solar radiation hesitated in a wide range from 0.6 kWh/m2 (December) to 5.2 kWh/m2 (June). Day duration varies on average from 10 hours in January, November and December to 17 hours in May, June and July. Day occupies 56% of the 8767 hours in year. On average the largest amount of energy reached the analyzed area in July: 157 kWh/m2 (15% of the annual average), while the smallest in December: 18 kWh/m2 (less than 2% of the annual average). The 75% of the average annual total of energy falls on the period from 1st March to 31th August (spring - summer). The range of the annual solar radiation was determined by the minimum of 980 kWh/m2 and the maximum of 1094 kWh/m2. In Sosnowiec the average annual irradiation total on the horizontal surface amounts to 1052 kWh/m2 (2003 - 2013)

  15. Decree of the Czechoslovak Atomic Energy Commission No. 191/1989 on procedures, terms and conditions for examining special professional qualification and competence of selected nuclear facility personnel

    International Nuclear Information System (INIS)

    1995-01-01

    The procedures, terms and conditions for examining special professional competence of selected nuclear facility personnel are specified, including conditions for professional training and for issuing licenses qualifying the personnel for their work. Nuclear safety-related jobs at nuclear facilities are listed. Professional licenses with a two-year term of validity are granted by the Czechoslovak Atomic Energy Agency (CSAEC) to candidates who have passed examination before the State Examination Commission. Personnel training may only be performed by bodies authorized for that by the CSAEC. The Decree entered into force on 1 January 1990. (J.B.)

  16. Photo-double ionisation of the Ne 2s studied in equal-energy-sharing condition at 20 eV above threshold

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, P. [CNR-IMIP, Area della Ricerca di Roma 1, CP10, 00016 Monterotondo Scalo (Italy); Otranto, S. [CONICET and Depto. de Fisica, Universidad Nacional del Sur, 8000 Bahia Blanca (Argentina); Garibotti, C.R. [CONICET and Centro Atomico Bariloche, 8400 S.C. de Bariloche (Argentina); Flammini, R. [CNR-IMIP, Area della Ricerca di Roma 1, CP10, 00016 Monterotondo Scalo (Italy); Alberti, G. [CNR-IMIP, Area della Ricerca di Roma 1, CP10, 00016 Monterotondo Scalo (Italy); Avaldi, L. [CNR-IMIP, Area della Ricerca di Roma 1, CP10, 00016 Monterotondo Scalo (Italy)]. E-mail: lorenzo.avaldi@imip.cnr.it

    2005-06-15

    The triple differential cross-section (TDCS) for the photo-double ionisation of Ne leading to the Ne{sup 2+}(2s{sup -2}2p{sup 6}) has been measured 20 eV above threshold in equal-energy-sharing conditions. The results are compared with the recently introduced SC3 model, which can be used to study targets different from He since it allows an easy implementation with different initial-state wavefunctions.

  17. Research document no. 19. The transposition conditions of the market institutions in transition economies (Russia). The energy case

    International Nuclear Information System (INIS)

    Locatelli, C.

    2000-07-01

    The majority of the institutions of the market economy exist today in Russia but they do not take on with the russian economic framework. One assists in fact with particular appropriation modes of these institutions, defining behaviors directed by logics of survival. To analyze the situation, the author presents the standard approaches of the economic transition in the case of the energy in russia and the institutional and organization models failure. (A.L.B.)

  18. Performance Assessment of a Hybrid Solar-Geothermal Air Conditioning System for Residential Application: Energy, Exergy, and Sustainability Analysis

    OpenAIRE

    Abbasi, Yasser; Baniasadi, Ehsan; Ahmadikia, Hossein

    2016-01-01

    This paper investigates the performance of a ground source heat pump that is coupled with a photovoltaic system to provide cooling and heating demands of a zero-energy residential building. Exergy and sustainability analyses have been conducted to evaluate the exergy destruction rate and SI of different compartments of the hybrid system. The effects of monthly thermal load variations on the performance of the hybrid system are investigated. The hybrid system consists of a vertical ground sour...

  19. The effects of degeneracy of the carrier ensemble on the energy loss rate and the high field mobility characteristics under the conditions of low lattice temperatures

    International Nuclear Information System (INIS)

    Basu, A.; Das, B.; Middya, T.R.; Bhattacharya, D.P.

    2017-01-01

    The rate of loss of energy of the non-equilibrium electrons to the acoustic mode lattice vibration in a degenerate semiconductor is obtained under the condition, when the lattice temperature is low enough, so that the traditional approximations like the elastic nature of the electron-phonon collisions and the truncation of the phonon distribution to the equipartition law are not valid any more. Using the results of the energy loss rate, the non-ohmic mobility is then calculated. Evaluating the loss rate and the non-ohmic mobility in degenerate samples of Si and Ge we find that significant changes in both the characteristics have been effected compared to that in the non-degenerate samples, in the regime of lower energy and for relatively lower fields. The effected changes are more significant the lower the lattice temperature is.

  20. Influence of drying conditions on the effective moisture diffusivity and energy requirements during the drying of pretreated and untreated pumpkin

    International Nuclear Information System (INIS)

    Tunde-Akintunde, Toyosi Y.; Ogunlakin, Grace O.

    2011-01-01

    Pumpkin as a fruit is consumed by both animals and humans. Its high moisture content makes it perishable and thus there is a need for drying as a means of preservation. Thin-layer drying characteristics for the samples dried using a hot-air dryer were obtained from the experiment data. The drying was observed to take place in the falling rate drying period. Ficks law was used to determine the moisture diffusivity which varied from a minimum of 1.19 x 10 -9 m 2 /s for untreated pumpkin samples dried at 40 o C to a maximum value of 4.27 x 10 -9 m 2 /s for steam blanched samples dried at 80 o C. The value of the energy of activation varied from 21.44 to 28.67 kJ/mol. The input energy values and specific energy requirement for thin-drying of pumpkin samples were found to be in the range of 317.8-458.1 kW h and 1588.8-2290.3 kW h/kg from 40 o C to 80 o C with a drying air velocity of 1.5 m/s respectively.