NASA Astrophysics Data System (ADS)
Döntgen, M.
2016-09-01
Energy-level densities are key for obtaining various chemical properties. In chemical kinetics, energy-level densities are used to predict thermochemistry and microscopic reaction rates. Here, an analytic energy-level density formulation is derived using inverse Laplace transformation of harmonic oscillator partition functions. Anharmonic contributions to the energy-level density are considered approximately using a literature model for the transition from harmonic to free motions. The present analytic energy-level density formulation for rigid rotor-harmonic oscillator systems is validated against the well-studied CO+O˙ H system. The approximate hindered rotor energy-level density corrections are validated against the well-studied H2O2 system. The presented analytic energy-level density formulation gives a basis for developing novel numerical simulation schemes for chemical processes.
Accuracy of analytic energy level formulas applied to hadronic spectroscopy of heavy mesons
NASA Technical Reports Server (NTRS)
Badavi, Forooz F.; Norbury, John W.; Wilson, John W.; Townsend, Lawrence W.
1988-01-01
Linear and harmonic potential models are used in the nonrelativistic Schroedinger equation to obtain article mass spectra for mesons as bound states of quarks. The main emphasis is on the linear potential where exact solutions of the S-state eigenvalues and eigenfunctions and the asymptotic solution for the higher order partial wave are obtained. A study of the accuracy of two analytical energy level formulas as applied to heavy mesons is also included. Cornwall's formula is found to be particularly accurate and useful as a predictor of heavy quarkonium states. Exact solution for all partial waves of eigenvalues and eigenfunctions for a harmonic potential is also obtained and compared with the calculated discrete spectra of the linear potential. Detailed derivations of the eigenvalues and eigenfunctions of the linear and harmonic potentials are presented in appendixes.
Vázquez, Juana; Harding, Michael E; Stanton, John F; Gauss, Jürgen
2011-05-10
A variational method for the calculation of low-lying vibrational energy levels of molecules with small amplitude vibrations is presented. The approach is based on the Watson Hamiltonian in rectilinear normal coordinates and characterized by a quasi-analytic integration over the kinetic energy operator (KEO). The KEO beyond the harmonic approximation is represented by a Taylor series in terms of the rectilinear normal coordinates around the equilibrium configuration. This formulation of the KEO enables its extension to arbitrary order until numerical convergence is reached for those states describing small amplitude motions and suitably represented with a rectilinear system of coordinates. A Gauss-Hermite quadrature grid representation of the anharmonic potential is used for all the benchmark examples presented. Results for a set of molecules with linear and nonlinear configurations, i.e., CO2, H2O, and formyl fluoride (HFCO), illustrate the performance of the method and the versatility of our implementation.
Multi-Level Experimental and Analytical Evaluation of Two Composite Energy Absorbers
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Littell, Justin D.; Fasanella, Edwin L.; Annett, Martin S.; Seal, Michael D., II
2015-01-01
Two composite energy absorbers were developed and evaluated at NASA Langley Research Center through multi-level testing and simulation performed under the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program. A conical-shaped energy absorber, designated the conusoid, was evaluated that consisted of four layers of hybrid carbon-Kevlar plain weave fabric oriented at [+45 deg/-45 deg/-45 deg/+45 deg] with respect to the vertical, or crush, direction. A sinusoidal-shaped energy absorber, designated the sinusoid, was developed that consisted of hybrid carbon-Kevlar plain weave fabric face sheets, two layers for each face sheet oriented at +/-45deg with respect to the vertical direction and a closed-cell ELFOAM P200 polyisocyanurate (2.0-lb/cu ft) foam core. The design goal for the energy absorbers was to achieve average floor-level accelerations of between 25- and 40-g during the full-scale crash test of a retrofitted CH-46E helicopter airframe, designated TRACT 2. Variations in both designs were assessed through dynamic crush testing of component specimens. Once the designs were finalized, subfloor beams of each configuration were fabricated and retrofitted into a barrel section of a CH-46E helicopter. A vertical drop test of the barrel section was conducted onto concrete to evaluate the performance of the energy absorbers prior to retrofit into TRACT 2. The retrofitted airframe was crash tested under combined forward and vertical velocity conditions onto soil, which is characterized as a sand/clay mixture. Finite element models were developed of all test articles and simulations were performed using LS-DYNA, a commercial nonlinear explicit transient dynamic finite element code. Test-analysis results are presented for each energy absorber as comparisons of time-history responses, as well as predicted and experimental structural deformations and progressive damage under impact loading for each evaluation level.
Analytic example of a free energy functional
Tutschka; Kahl
2000-09-01
We use the ideas of Percus for the construction of classical density functionals for two model interactions: simple hard spheres and adhesive hard spheres (AHSs). The required input, the properties of the uniform fluid, is taken from the analytic mean spherical solution for these two systems. For hard spheres we derive-via a bilinear decomposition of the direct correlation functions-a set of basis functions, which is the same as the one presented by Rosenfeld in his fundamental measure theory framework. For AHSs additional basis functions have to be considered to ensure the bilinear decomposition of the direct correlation functions; we present an expression for the free energy functional for the one-component case.
Analytic computation of average energy of neutrons inducing fission
Clark, Alexander Rich
2016-08-12
The objective of this report is to describe how I analytically computed the average energy of neutrons that induce fission in the bare BeRP ball. The motivation of this report is to resolve a discrepancy between the average energy computed via the FMULT and F4/FM cards in MCNP6 by comparison to the analytic results.
Analytical model for nonlinear piezoelectric energy harvesting devices
NASA Astrophysics Data System (ADS)
Neiss, S.; Goldschmidtboeing, F.; Kroener, M.; Woias, P.
2014-10-01
In this work we propose analytical expressions for the jump-up and jump-down point of a nonlinear piezoelectric energy harvester. In addition, analytical expressions for the maximum power output at optimal resistive load and the 3 dB-bandwidth are derived. So far, only numerical models have been used to describe the physics of a piezoelectric energy harvester. However, this approach is not suitable to quickly evaluate different geometrical designs or piezoelectric materials in the harvester design process. In addition, the analytical expressions could be used to predict the jump-frequencies of a harvester during operation. In combination with a tuning mechanism, this would allow the design of an efficient control algorithm to ensure that the harvester is always working on the oscillator's high energy attractor.
High-Dimensional Topological Insulators with Quaternionic Analytic Landau Levels
NASA Astrophysics Data System (ADS)
Li, Yi; Wu, Congjun
2013-05-01
We study the three-dimensional topological insulators in the continuum by coupling spin-1/2 fermions to the Aharonov-Casher SU(2) gauge field. They exhibit flat Landau levels in which orbital angular momentum and spin are coupled with a fixed helicity. The three-dimensional lowest Landau level wave functions exhibit the quaternionic analyticity as a generalization of the complex analyticity of the two-dimensional case. Each Landau level contributes one branch of gapless helical Dirac modes to the surface spectra, whose topological properties belong to the Z2 class. The flat Landau levels can be generalized to an arbitrary dimension. Interaction effects and experimental realizations are also studied.
Data and Analytics to Inform Energy Retrofit of High Performance Buildings
Hong, Tianzhen; Yang, Le; Hill, David; Feng, Wei
2014-01-25
Buildings consume more than one-third of the world?s primary energy. Reducing energy use in buildings with energy efficient technologies is feasible and also driven by energy policies such as energy benchmarking, disclosure, rating, and labeling in both the developed and developing countries. Current energy retrofits focus on the existing building stocks, especially older buildings, but the growing number of new high performance buildings built around the world raises a question that how these buildings perform and whether there are retrofit opportunities to further reduce their energy use. This is a new and unique problem for the building industry. Traditional energy audit or analysis methods are inadequate to look deep into the energy use of the high performance buildings. This study aims to tackle this problem with a new holistic approach powered by building performance data and analytics. First, three types of measured data are introduced, including the time series energy use, building systems operating conditions, and indoor and outdoor environmental parameters. An energy data model based on the ISO Standard 12655 is used to represent the energy use in buildings in a three-level hierarchy. Secondly, a suite of analytics were proposed to analyze energy use and to identify retrofit measures for high performance buildings. The data-driven analytics are based on monitored data at short time intervals, and cover three levels of analysis ? energy profiling, benchmarking and diagnostics. Thirdly, the analytics were applied to a high performance building in California to analyze its energy use and identify retrofit opportunities, including: (1) analyzing patterns of major energy end-use categories at various time scales, (2) benchmarking the whole building total energy use as well as major end-uses against its peers, (3) benchmarking the power usage effectiveness for the data center, which is the largest electricity consumer in this building, and (4) diagnosing HVAC
Analytical solutions for bacterial energy taxis (chemotaxis): Traveling bacterial bands
NASA Astrophysics Data System (ADS)
Long, Wei; Hilpert, Markus
2007-11-01
Motile bacteria may form bands that travel with a constant speed of propagation through a medium containing a dissolved substrate, to which they respond energy tactically. We generalize the analytical solution by Keller and Segel for such bands by accounting for (1) the presence of a porous medium, (2) substrate consumption described by a Monod kinetics model, and (3) an energy tactic response model derived by Rivero et al. Specifically, we determine the concentration profiles of the bacteria and the substrate. We also derive various expressions for the band velocity. The band velocity is also shown to equal the energy tactic velocity at the bacterial peak divided by tortuosity.
Energy level statistics of a critical random matrix ensemble
NASA Astrophysics Data System (ADS)
Ndawana, Macleans L.; Kravtsov, Vladimir E.
2003-03-01
We study energy level statistics of a critical random matrix ensemble of power-law banded complex Hermitian matrices. We compute the level compressibility via the level-number variance and compare it with the analytical formula for the exactly solvable model of Moshe, Neuberger and Shapiro.
Roll levelling semi-analytical model for process optimization
NASA Astrophysics Data System (ADS)
Silvestre, E.; Garcia, D.; Galdos, L.; Saenz de Argandoña, E.; Mendiguren, J.
2016-08-01
Roll levelling is a primary manufacturing process used to remove residual stresses and imperfections of metal strips in order to make them suitable for subsequent forming operations. In the last years the importance of this process has been evidenced with the apparition of Ultra High Strength Steels with strength > 900 MPa. The optimal setting of the machine as well as a robust machine design has become critical for the correct processing of these materials. Finite Element Method (FEM) analysis is the widely used technique for both aspects. However, in this case, the FEM simulation times are above the admissible ones in both machine development and process optimization. In the present work, a semi-analytical model based on a discrete bending theory is presented. This model is able to calculate the critical levelling parameters i.e. force, plastification rate, residual stresses in a few seconds. First the semi-analytical model is presented. Next, some experimental industrial cases are analyzed by both the semi-analytical model and the conventional FEM model. Finally, results and computation times of both methods are compared.
A Three Level Analytic Model for Alkali Vapor Lasers
Hager, Gordon D.; Perram, Glen P.
2010-10-08
A three level analytic model for optically pumped alkali metal vapor lasers is developed considering the steady-state rate equations for the longitudinally averaged number densities of the ground {sup 2}S{sub 1/2} and first excited {sup 2}P{sub 1/2} and {sup 2}P{sub 3/2} states. The threshold pump intensity includes both the requirements to fully bleach the pump transition and exceed optical losses, typically about 200 W/cm{sup 2}. Slope efficiency depends critically on the fraction of incident photons absorbed and the overlap of pump and resonator modes, approaching the quantum efficiency of 0.95-0.98, depending on alkali atom. For efficient operation, the collisional relaxation between the two upper levels should be fast relative to stimulated emission. By assuming a statistical distribution between the upper levels, the limiting analytic solution for the quasi-two level system is achieved. Application of the model and comparisons to recent laser demonstrations is presented.
Use of groundwater levels with the PULSE analytical model.
Rutledge, Albert T
2014-01-01
The PULSE analytical model, which calculates daily groundwater discharge on the basis of user-specified recharge, was originally developed for calibration using streamflow data. This article describes a model application in which groundwater level data constitute the primary control on model input. As a test case, data were analyzed from a small basin in central Pennsylvania in which extensive groundwater level data are available. The timing and intensity of daily water-level rises are used to ascertain temporal distribution of recharge, and the simulated groundwater discharge hydrograph has shape features that are similar to the streamflow hydrograph. This article does not include details about calibration, but some steps are illustrated and general procedures are described for calibration in specific hydrologic studies. The PULSE model can be used to assess results of fully automated base flow methods and can be used to define groundwater recharge and discharge at a relatively small time scale.
Device-Level Data Analytics to Guide Policy
NASA Astrophysics Data System (ADS)
Glasgo, Brock
This dissertation is comprised of four studies that examine issues where submetered device-level energy use data can be used to inform energy efficiency policy and investment decision making in residential buildings. In addition to identifying applications and developing the methods for incorporating these data in engineering and economic analyses, the nontechnical aspects of these issues are also considered as implementation of these solutions depends on more than their technical feasibility. (Abstract shortened by ProQuest.).
Analytic energy gradients in closed-shell coupled-cluster theory with spin-orbit coupling.
Wang, Fan; Gauss, Jürgen
2008-11-07
Gradients in closed-shell coupled-cluster (CC) theory with spin-orbit coupling included in the post Hartree-Fock treatment have been implemented at the CC singles and doubles (CCSD) level and at the CCSD level augmented by a perturbative treatment of triple excitations [CCSD(T)]. The additional computational effort required in analytic energy-gradient calculations is roughly the same as that for ground-state energy calculations in the case of CCSD, and it is about twice in the case of CCSD(T) calculations. The structures, harmonic frequencies, and dipole moments of some heavy-element compounds have been calculated using the present analytic energy-gradient techniques including spin-orbit coupling. The results show that spin-orbit coupling can have a significant influence on both the equilibrium structure and the harmonic vibrational frequencies and that its inclusion is essential to obtain reliable and accurate estimates for geometrical parameters of heavy-element compounds.
Variation of analytical results for peanuts in energy bars and milk chocolate.
Trucksess, Mary W; Whitaker, Thomas B; Slate, Andrew B; Williams, Kristina M; Brewer, Vickery A; Whittaker, Paul; Heeres, James T
2004-01-01
Peanuts contain proteins that can cause severe allergic reactions in some sensitized individuals. Studies were conducted to determine the percentage of recovery by an enzyme-linked immunosorbent assay (ELISA) method in the analysis for peanuts in energy bars and milk chocolate and to determine the sampling, subsampling, and analytical variances associated with testing energy bars and milk chocolate for peanuts. Food products containing chocolate were selected because their composition makes sample preparation for subsampling difficult. Peanut-contaminated energy bars, noncontaminated energy bars, incurred milk chocolate containing known levels of peanuts, and peanut-free milk chocolate were used. A commercially available ELISA kit was used for analysis. The sampling, sample preparation, and analytical variances associated with each step of the test procedure to measure peanut protein were determined for energy bars. The sample preparation and analytical variances were determined for milk chocolate. Variances were found to be functions of peanut concentration. Sampling and subsampling variability associated with energy bars accounted for 96.6% of the total testing variability. Subsampling variability associated with powdered milk chocolate accounted for >60% of the total testing variability. The variability among peanut test results can be reduced by increasing sample size, subsample size, and number of analyses. For energy bars the effect of increasing sample size from 1 to 4 bars, subsample size from 5 to 20 g, and number of aliquots quantified from 1 to 2 on reducing the sampling, sample preparation, and analytical variance was demonstrated. For powdered milk chocolate, the effects of increasing subsample size from 5 to 20 g and number of aliquots quantified from 1 to 2 on reducing sample preparation and analytical variances were demonstrated. This study serves as a template for application to other foods, and for extrapolation to different sizes of samples and
Two-level laser: Analytical results and the laser transition
Gartner, Paul
2011-11-15
The problem of the two-level laser is studied analytically. The steady-state solution is expressed as a continued fraction and allows for accurate approximation by rational functions. Moreover, we show that the abrupt change observed in the pump dependence of the steady-state population is directly connected to the transition to the lasing regime. The condition for a sharp transition to Poissonian statistics is expressed as a scaling limit of vanishing cavity loss and light-matter coupling, {kappa}{yields}0, g{yields}0, such that g{sup 2}/{kappa} stays finite and g{sup 2}/{kappa}>2{gamma}, where {gamma} is the rate of nonradiative losses. The same scaling procedure is also shown to describe a similar change to the Poisson distribution in the Scully-Lamb laser model, suggesting that the low-{kappa}, low-g asymptotics is of more general significance for the laser transition.
Trace level detection of analytes using artificial olfactometry
NASA Technical Reports Server (NTRS)
Lewis, Nathan S. (Inventor); Severin, Erik J. (Inventor); Wong, Bernard (Inventor)
2002-01-01
The present invention provides a device for detecting the presence of an analyte, such as for example, a lightweight device, including: a sample chamber having a fluid inlet port for the influx of the analyte; a fluid concentrator in flow communication with the sample chamber wherein the fluid concentrator has an absorbent material capable of absorbing the analyte and capable of desorbing a concentrated analyte; and an array of sensors in fluid communication with the concentrated analyte to be released from the fluid concentrator.
Not Available
1992-09-01
The Hawaii Energy Strategy program, or HES, is a set of seven projects which will produce an integrated energy strategy for the State of Hawaii. It will include a comprehensive energy vulnerability assessment with recommended courses of action to decrease Hawaii's energy vulnerability and to better prepare for an effective response to any energy emergency or supply disruption. The seven projects are designed to increase understanding of Hawaii's energy situation and to produce recommendations to achieve the State energy objectives of: Dependable, efficient, and economical state-wide energy systems capable of supporting the needs of the people, and increased energy self-sufficiency. The seven projects under the Hawaii Energy Strategy program include: Project 1: Develop Analytical Energy Forecasting Model for the State of Hawaii. Project 2: Fossil Energy Review and Analysis. Project 3: Renewable Energy Resource Assessment and Development Program. Project 4: Demand-Side Management Program. Project 5: Transportation Energy Strategy. Project 6: Energy Vulnerability Assessment Report and Contingency Planning. Project 7: Energy Strategy Integration and Evaluation System.
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2014 CFR
2014-04-01
... analytical method; or (3) Establish a safe level based on other appropriate scientific, technical, or... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Safe levels and analytical methods for food... § 530.22 Safe levels and analytical methods for food-producing animals. (a) FDA may establish a safe...
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Safe levels and analytical methods for food... § 530.22 Safe levels and analytical methods for food-producing animals. (a) FDA may establish a safe... analytical method; or (3) Establish a safe level based on other appropriate scientific, technical, or...
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Safe levels and analytical methods for food... § 530.22 Safe levels and analytical methods for food-producing animals. (a) FDA may establish a safe... analytical method; or (3) Establish a safe level based on other appropriate scientific, technical, or...
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Safe levels and analytical methods for food... § 530.22 Safe levels and analytical methods for food-producing animals. (a) FDA may establish a safe... analytical method; or (3) Establish a safe level based on other appropriate scientific, technical, or...
Trace level detection of analytes using artificial olfactometry
NASA Technical Reports Server (NTRS)
Lewis, Nathan S. (Inventor); Severin, Erik J. (Inventor); Wong, Bernard (Inventor); Kelso, David M. (Inventor); Munoz, Beth C. (Inventor)
2001-01-01
The present invention provides methods for detecting the presence of an analyte indicative of various medical conditions, including halitosis, periodontal disease and other diseases are also disclosed.
Energy level transitions of gas in a 2D nanopore
Grinyaev, Yurii V.; Chertova, Nadezhda V.; Psakhie, Sergei G.
2015-10-27
An analytical study of gas behavior in a 2D nanopore was performed. It is shown that the temperature dependence of gas energy can be stepwise due to transitions from one size-quantized subband to another. Taking into account quantum size effects results in energy level transitions governed by the nanopore size, temperature and gas density. This effect leads to an abrupt change of gas heat capacity in the nanopore at the above varying system parameters.
21 CFR 530.40 - Safe levels and availability of analytical methods.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Safe levels and availability of analytical methods... Safe levels and availability of analytical methods. (a) In accordance with § 530.22, the following safe... accordance with § 530.22, the following analytical methods have been accepted by FDA: ...
21 CFR 530.40 - Safe levels and availability of analytical methods.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Safe levels and availability of analytical methods... Safe levels and availability of analytical methods. (a) In accordance with § 530.22, the following safe... accordance with § 530.22, the following analytical methods have been accepted by FDA: ...
21 CFR 530.40 - Safe levels and availability of analytical methods.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Safe levels and availability of analytical methods... Safe levels and availability of analytical methods. (a) In accordance with § 530.22, the following safe...) In accordance with § 530.22, the following analytical methods have been accepted by FDA: [Reserved] ...
21 CFR 530.40 - Safe levels and availability of analytical methods.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Safe levels and availability of analytical methods... Safe levels and availability of analytical methods. (a) In accordance with § 530.22, the following safe... accordance with § 530.22, the following analytical methods have been accepted by FDA: ...
Trace level detection of analytes using artificial olfactometry
NASA Technical Reports Server (NTRS)
Lewis, Nathan S. (Inventor); Severin, Erik J. (Inventor); Wong, Bernard (Inventor)
2001-01-01
The present invention provides a device for detecting the presence of an analyte, wherein said analyte is a microorganism marker gas. The device comprises a sample chamber having a fluid inlet port for the influx of the microorganism marker gas; a fluid concentrator in flow communication with the sample chamber, wherein the fluid concentrator has an absorbent material capable of absorbing the microorganism marker gas and thereafter releasing a concentrated microorganism marker gas; and an array of sensors in fluid communication with the concentrated microorganism marker gas. The sensor array detects and identifies the marker gas upon its release from fluid concentrate.
Energy levels of bilayer graphene quantum dots
NASA Astrophysics Data System (ADS)
da Costa, D. R.; Zarenia, M.; Chaves, Andrey; Farias, G. A.; Peeters, F. M.
2015-09-01
Within a tight binding approach we investigate the energy levels of hexagonal and triangular bilayer graphene (BLG) quantum dots (QDs) with zigzag and armchair edges. We study AA- and AB- (Bernal) stacked BLG QDs and obtain the energy levels in both the absence and the presence of a perpendicular electric field (i.e., biased BLG QDs). Our results show that the size dependence of the energy levels is different from that of monolayer graphene QDs. The energy spectrum of AB-stacked BLG QDs with zigzag edges exhibits edge states which spread out into the opened energy gap in the presence of a perpendicular electric field. We found that the behavior of these edges states is different for the hexagonal and triangular geometries. In the case of AA-stacked BLG QDs, the electron and hole energy levels cross each other in both cases of armchair and zigzag edges as the dot size or the applied bias increases.
A Global Analytical Representation of the Potential Energy Surface of the FHF(-) Anion.
Cornaton, Yann; Marquardt, Roberto
2016-08-04
A global analytical representation of the potential energy hypersurface of the lowest adiabatic electronic state of the FHF(-) anion is derived from ab initio calculations at the coupled cluster level of theory with full single and double and perturbative triple excitations using explicitly correlated atomic basis functions. The new compact function of interatomic distances combines covalent short-range and long-range electrostatic interaction forms and assesses accurately both the lowest reaction channels between the F(-) and HF fragments, with reaction enthalpies to within 1 kJ mol(-1), as well as vibrational terms to within 1.5 cm(-1) deviation from experimental values.
State-Level Benefits of Energy Efficiency
Tonn, Bruce Edward
2007-02-01
This report describes benefits attributable to state-level energy efficiency programs. Nationwide, state-level energy efficiency programs have targeted all sectors of the economy and have employed a wide range of methods to promote energy efficiency. Standard residential and industrial programs typically identify between 20 to 30% energy savings in homes and plants, respectively. Over a 20 year period of time, an average state that aggressively pursues even a limited array of energy efficiency programs can potentially reduce total state energy use by as much as 20%. Benefit-cost ratios of effective energy efficiency programs typically exceed 3 to 1 and are much higher when non-energy and macroeconomic benefits are included. Indeed, energy efficiency and associated programs and investments can create significant numbers of new jobs and enhance state tax revenues. Several states have incorporated energy efficiency into their economic development programs. It should also be noted that increasing amounts of venture capital are being invested in the energy sector in general and in specific technologies like solar power in particular. Well-designed energy efficiency programs can be expected to help overcome numerous barriers to the market penetration of energy efficient technologies and accelerate the market penetration of the technologies.
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Safe levels and analytical methods for food-producing animals. 530.22 Section 530.22 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... § 530.22 Safe levels and analytical methods for food-producing animals. (a) FDA may establish a safe...
Olevanov, M; Proshina, O; Rakhimova, T; Voloshin, D
2008-08-01
An analytical approach is used to calculate an ion energy distribution function (IEDF) in a dual frequency (DF) collisionless rf discharge in argon. Three possible limit regimes for frequency relations in the DF discharge are discussed. The analytical IEDF is obtained for the intermediate-frequency case, which is most applicable in plasma-processing technologies. The analytical expressions for an ion spectrum width as well as for the minimum and maximum ion energies are derived. The analytical theory is compared with a particle-in-cell Monte Carlo numerical simulation and also with the results of a semianalytical model.
Matching renewable energy systems to village-level energy needs
Ashworth, J.H.; Neuendorffer, J.W.
1980-06-01
This report provides a five step process for matching alternative renewable energy technologies with energy needs in rural villages of developing countries. Analytic tools are given for each of the five steps as well as information that can be expected. Twelve characterization criteria are developed to assist in the matching process. Three of these criteria, called discrimination criteria, are used for preliminary screening of technology possibilities for each need. The other criteria address site-specific temporal, climatic, social, cultural, and environmental characteristics of the energy need, technology, and cost considerations. To illustrate the matching process, seven basic human needs for energy are matched with seven potential renewable energy technologies. The final portion of the paper discusses the advantages of such a matching process and the resources required to initiate such an effort within a development project. Specific recommendations are given for field-testing this process and actions that could be taken immediately in basic research and development, applied research and technology modification, demonstrations, and commercialization to assist in the future diffusion of renewable energy technologies to rural areas of developing countries.
Energy Levels of Hydrogen and Deuterium
National Institute of Standards and Technology Data Gateway
SRD 142 Energy Levels of Hydrogen and Deuterium (Web, free access) This database provides theoretical values of energy levels of hydrogen and deuterium for principle quantum numbers n = 1 to 200 and all allowed orbital angular momenta l and total angular momenta j. The values are based on current knowledge of the revelant theoretical contributions including relativistic, quantum electrodynamic, recoil, and nuclear size effects.
Energy levels of hybrid monolayer-bilayer graphene quantum dots
NASA Astrophysics Data System (ADS)
Mirzakhani, M.; Zarenia, M.; Ketabi, S. A.; da Costa, D. R.; Peeters, F. M.
2016-04-01
Often real samples of graphene consist of islands of both monolayer and bilayer graphene. Bound states in such hybrid quantum dots are investigated for (i) a circular single-layer graphene quantum dot surrounded by an infinite bilayer graphene sheet and (ii) a circular bilayer graphene quantum dot surrounded by an infinite single-layer graphene. Using the continuum model and applying zigzag boundary conditions at the single-layer-bilayer graphene interface, we obtain analytical results for the energy levels and the corresponding wave spinors. Their dependence on perpendicular magnetic and electric fields are studied for both types of quantum dots. The energy levels exhibit characteristics of interface states, and we find anticrossings and closing of the energy gap in the presence of a bias potential.
Omitaomu, Olufemi A; Maness, Christopher S; Kramer, Ian S; Kodysh, Jeffrey B; Bhaduri, Budhendra L; Steed, Chad A; Karthik, Rajasekar; Nugent, Philip J; Myers, Aaron T
2012-01-01
We present an integrated geovisual analytics framework for utility consumers to interactively analyze and benchmark their energy consumption. The framework uses energy and property data already available with the utility companies and county governments respectively. The motivation for the developed framework is the need for citizens to go beyond the conventional utility bills in understanding the patterns in their energy consumption. There is also a need for citizens to go beyond one-time improvements that are often not monitored and measured over time. Some of the features of the framework include the ability for citizens to visualize their historical energy consumption data along with weather data in their location. The quantity of historical energy data available is significantly more than what is available from utility bills. An overlay of the weather data provides users with a visual correlation between weather patterns and their energy consumption patterns. Another feature of the framework is the ability for citizens to compare their consumption on an aggregated basis to that of their peers other citizens living in houses of similar size and age and within the same or different geographical boundaries, such as subdivision, zip code, or county. The users could also compare their consumption to others based on the size of their family and other attributes. This feature could help citizens determine if they are among the best in class . The framework can also be used by the utility companies to better understand their customers and to plan their services. To make the framework easily accessible, it is developed to be compatible with mobile consumer electronics devices.
Energy demand analytics using coupled technological and economic models
Impacts of a range of policy scenarios on end-use energy demand are examined using a coupling of MARKAL, an energy system model with extensive supply and end-use technological detail, with Inforum LIFT, a large-scale model of the us. economy with inter-industry, government, and c...
Energy demand analytics using coupled technological and economic models
Impacts of a range of policy scenarios on end-use energy demand are examined using a coupling of MARKAL, an energy system model with extensive supply and end-use technological detail, with Inforum LIFT, a large-scale model of the us. economy with inter-industry, government, and c...
Tolias, P.; Ratynskaia, S.; Angelis, U. de
2015-08-15
The soft mean spherical approximation is employed for the study of the thermodynamics of dusty plasma liquids, the latter treated as Yukawa one-component plasmas. Within this integral theory method, the only input necessary for the calculation of the reduced excess energy stems from the solution of a single non-linear algebraic equation. Consequently, thermodynamic quantities can be routinely computed without the need to determine the pair correlation function or the structure factor. The level of accuracy of the approach is quantified after an extensive comparison with numerical simulation results. The approach is solved over a million times with input spanning the whole parameter space and reliable analytic expressions are obtained for the basic thermodynamic quantities.
Analytic saddlepoint approximation for ionization energy loss distributions
NASA Astrophysics Data System (ADS)
Sjue, S. K. L.; George, R. N.; Mathews, D. G.
2017-09-01
We present a saddlepoint approximation for ionization energy loss distributions, valid for arbitrary relativistic velocities of the incident particle 0 < v / c < 1 , provided that ionizing collisions are still the dominant energy loss mechanism. We derive a closed form solution closely related to Moyal's distribution. This distribution is intended for use in simulations with relatively low computational overhead. The approximation generally reproduces the Vavilov most probable energy loss and full width at half maximum to better than 1% and 10%, respectively, with significantly better agreement as Vavilov's κ approaches 1.
NASA Technical Reports Server (NTRS)
Ivanov, V. Y.; Sipov, N. K.; Shneyder, V. A.
1977-01-01
Analytical representations of the elastic scattering cross sections of electrons with energies of 0.01-1 keV in atmospheric gases of N2, O2, O are given. These representations are suitable for the Monte Carlo method.
Process models: analytical tools for managing industrial energy systems
Howe, S O; Pilati, D A; Balzer, C; Sparrow, F T
1980-01-01
How the process models developed at BNL are used to analyze industrial energy systems is described and illustrated. Following a brief overview of the industry modeling program, the general methodology of process modeling is discussed. The discussion highlights the important concepts, contents, inputs, and outputs of a typical process model. A model of the US pulp and paper industry is then discussed as a specific application of process modeling methodology. Applications addressed with the case study results include projections of energy demand, conservation technology assessment, energy-related tax policies, and sensitivity analysis. A subsequent discussion of these results supports the conclusion that industry process models are versatile and powerful tools for managing industrial energy systems.
Mapping Energy Levels for Organic Heterojunctions.
Li, Yiying; Li, Peicheng; Lu, Zheng-Hong
2017-06-01
An organic semiconductor thin film is a solid-state matter comprising one or more molecules. For applications in electronics and photonics, several distinct functional organic thin films are stacked together to create a variety of devices such as organic light-emitting diodes and organic solar cells. The energy levels at these thin-film junctions dictate various electronic processes such as the charge transport across these junctions, the exciton dissociation rates at donor-acceptor molecular interfaces, and the charge trapping during exciton formation in a host-dopant system. These electronic processes are vital to a device's performance and functionality. To uncover a general scientific principle in governing the interface energy levels, highest occupied molecular orbitals, and vacuum level dipoles, herein a comprehensive experimental research is conducted on several dozens of organic-organic heterojunctions representative of various device applications. It is found that the experimental data map on interface energy levels, after correcting variables such as molecular orientation-dependent ionization energies, consists of three distinct regions depending on interface fundamental physical parameters such as Fermi energy, work function, highest occupied molecular orbitals, and lowest unoccupied molecular orbitals. This general energy map provides a master guide in selection of new materials for fabricating future generations of organic semiconductor devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Yoo, Ji Ho; Köckert, Hansjochen; Mullaney, John C.; Stephens, Susanna L.; Evans, Corey J.; Walker, Nicholas R.; Le Roy, Robert. J.
2016-12-01
Pure rotational spectra of PbI and InI are interpreted to yield a full analytic potential energy function for each molecule. Rotational spectra for PbI have been retrieved from literature sources to perform the analysis. Rotational transition frequencies for excited vibrational states of InI (0 < v < 11) are measured during this work. Ignoring hyperfine splittings, Bv and Dv values are used to generate a set of ;synthetic; pure R (0) transitions for each vibrational level. These are then fitted to an ;Expanded Morse Oscillator; (EMO) potential using the direct-potential-fit program, dPOTFIT. The well-depth parameter, De , is fixed at a literature value, while values of the equilibrium distance re and EMO exponent-coefficient expansion (potential-shape) parameters are determined from the fits. Comparison with potential functions determined after including older mid-IR and visible electronic transition data shows that our analysis of the pure microwave data alone yields potential energy functions that accurately predict (to better than 1%) the overtone vibrational energies far beyond the range spanned by the levels for which the microwave data is available.
A Climate Data Analytical Tool Used to Validate CERES Clouds Pixel Level Data
NASA Astrophysics Data System (ADS)
Chu, C.
2016-12-01
CERES provides top of the atmosphere (TOA) measurements of both reflected-solar and emitted-thermal radiation. There are now 35 data years of Clouds and Earth's Radiant Energy System (CERES) observations across three satellites (Terra, Aqua, and Suomi NPP). These measurements are combined with clear and cloud properties from imager data (MODIS for Terra and Aqua and VIIRS for Suomi NPP) to obtain flux profiles through the atmosphere and at the Earth surface level products for each satellite overpass and gridded products which could be hourly, daily, monthly or a climatology. Because there are multiple versions (Edition3 and Edition4 for Terra and Aqua and Edition1 for NPP) of the various data products, an efficient climate data analytical tool is needed to support validation and analysis. The characteristics of this environment are (1) large number of parameters (around 1000), (2) large data volume that increased daily (approaching a PetaByte in total), (3) preprocessing data of the final or intermediate products before it is used for validation, (4) ability for users to manipulate the data such as filtering and differencing to identify issues, and (5) a display capability to show their work in progress. The tool has allowed CERES algorithm developers to browse large amount of data to identify issues and trends in a short period time. This poster will demonstrate how this analytical tool meets the above requirements with a search interface and a feature called "math" to process and filter the data on the fly.
Analytic insights into nonlocal energy flux in laser fusion targets
NASA Astrophysics Data System (ADS)
Manheimer, Wallace; Cotombant, Denis; Schmitt, Andrew
2016-10-01
There have been several attempts to utilize a Krook model in a laser implosion simulation to study the effects of nonlocal transport of energetic electrons. Frequently these numerical studies give different and even contradictory results. As these studies use complex radiation hydrodynamics codes, with many processes simultaneously going on, there is little understanding of the various results. The results differ for two reasons, first, differences in the mathematical formulation; and second, differences in the numerical methods. This presents what hopefully will be a much-improved formulation, including a proper model for the Coulomb logarithm where it describes energetic particle collisions in the cool regions of the plasma. It presents analytic insights and simple calculations, which can be used as a check on the numerical results, and discusses various difficulties of implementation. Work supported by US DoE NNSA and ONR.
Analytical expressions for partial wave two-body Coulomb transition matrices at ground-state energy
NASA Astrophysics Data System (ADS)
Kharchenko, V. F.
2016-11-01
Leaning upon the Fock method of the stereographic projection of the three-dimensional momentum space onto the four-dimensional unit sphere the possibility of the analytical solving of the Lippmann-Schwinger integral equation for the partial wave two-body Coulomb transition matrix at the ground bound state energy has been studied. In this case new expressions for the partial p-, d- and f-wave two-body Coulomb transition matrices have been obtained in the simple analytical form. The developed approach can also be extended to determine analytically the partial wave Coulomb transition matrices at the energies of excited bound states.
Experimental and Analytical Studies on Pyroelectric Waste Heat Energy Conversion
NASA Astrophysics Data System (ADS)
Lee, Felix
This study is concerned with direct conversion of thermal energy into electrical energy by subjecting pyroelectric materials to the Olsen cycle. The Olsen cycle consists of two isoelectric field and two isothermal process on the electric displacement versus electric field diagram. The energy and power generation capabilities of copolymer poly(vinylidene fluoridetrifluorethylene) [P(VDF-TrFE)] films and lead lanthanum zirconate titanate (PLZT) ceramics were evaluated by executing the Olsen cycle via so-called "stamping experiments" and "dipping experiments". The stamping experiments consisted of alternatively pressing a pyroelectric material in thermal contact with hot and cold aluminum blocks under specified electric fields. It was performed to assess the pyroelectric energy conversion performance using heat conduction. The largest energy density generated in the stamping experiments was 155 J/L/cycle with 60/40 P(VDF-TrFE) thin film at 0.066 Hz between 25 and 110°C and electric fields cycled between 20 and 35 MV/m. This energy density exceeded the 130 J/L/cycle achieved by our previous prototypical device using oscillatory laminar convective heat transfer. However, the performance was limited by poor thermal contact between the aluminum blocks and pyroelectric material and also by excessive leakage current inherent to P(VDF-TrFE) at high temperatures and/or large electric fields. On the other hand, dipping experiments consisted of successively immersing a pyroelectric material into isothermal hot and cold thermal reservoirs at different temperatures while simultaneously cycling the electric fields. It was performed on relaxor ferroelectric
Developing an Analytical Framework for Argumentation on Energy Consumption Issues
ERIC Educational Resources Information Center
Jin, Hui; Mehl, Cathy E.; Lan, Deborah H.
2015-01-01
In this study, we aimed to develop a framework for analyzing the argumentation practice of high school students and high school graduates. We developed the framework in a specific context--how energy consumption activities such as changing diet, converting forests into farmlands, and choosing transportation modes affect the carbon cycle. The…
Developing an Analytical Framework for Argumentation on Energy Consumption Issues
ERIC Educational Resources Information Center
Jin, Hui; Mehl, Cathy E.; Lan, Deborah H.
2015-01-01
In this study, we aimed to develop a framework for analyzing the argumentation practice of high school students and high school graduates. We developed the framework in a specific context--how energy consumption activities such as changing diet, converting forests into farmlands, and choosing transportation modes affect the carbon cycle. The…
Analytic function for the H + CH/sub 3/ in equilibrium CH/sub 4/ potential energy surface
Duchovic, R.J.; Hase, W.L.; Schlegel, H.B.
1984-03-29
An analytic function for the ground electronic state CH/sub 4/ in equilibrium CH/sub 3/ + H potential energy surface is proposed. This model makes use of a switching-function formalism and is based on both spectroscopic data and ab initio calculations at the MP4/6-31G** level. The proposed general symmetric analytic potential is suitable for use in quasiclassical trajectory studies of the CH/sub 4/ in equilibrium CH/sub 3/ + H reaction. 9 figures, 4 tables.
NASA Astrophysics Data System (ADS)
Harne, R. L.; Zhang, Chunlin; Li, Bing; Wang, K. W.
2016-07-01
Impulsive energies are abundant throughout the natural and built environments, for instance as stimulated by wind gusts, foot-steps, or vehicle-road interactions. In the interest of maximizing the sustainability of society's technological developments, one idea is to capture these high-amplitude and abrupt energies and convert them into usable electrical power such as for sensors which otherwise rely on less sustainable power supplies. In this spirit, the considerable sensitivity to impulse-type events previously uncovered for bistable oscillators has motivated recent experimental and numerical studies on the power generation performance of bistable vibration energy harvesters. To lead to an effective and efficient predictive tool and design guide, this research develops a new analytical approach to estimate the electroelastic response and power generation of a bistable energy harvester when excited by an impulse. Comparison with values determined by direct simulation of the governing equations shows that the analytically predicted net converted energies are very accurate for a wide range of impulse strengths. Extensive experimental investigations are undertaken to validate the analytical approach and it is seen that the predicted estimates of the impulsive energy conversion are in excellent agreement with the measurements, and the detailed structural dynamics are correctly reproduced. As a result, the analytical approach represents a significant leap forward in the understanding of how to effectively leverage bistable structures as energy harvesting devices and introduces new means to elucidate the transient and far-from-equilibrium dynamics of nonlinear systems more generally.
Vibrational energy levels of CH5+
NASA Astrophysics Data System (ADS)
Wang, Xiao-Gang; Carrington, Tucker
2008-12-01
We present a parallelized contracted basis-iterative method for calculating numerically exact vibrational energy levels of CH5+ (a 12-dimensional calculation). We use Radau polyspherical coordinates and basis functions that are products of eigenfunctions of bend and stretch Hamiltonians. The bend eigenfunctions are computed in a nondirect product basis with more than 200×106 functions and the stretch functions are computed in a product potential optimized discrete variable basis. The basis functions have amplitude in all of the 120 equivalent minima. Many low-lying levels are well converged. We find that the energy level pattern is determined in part by the curvature and width of the valley connecting the minima and in part by the slope of the walls of this valley but does not depend on the height or shape of the barriers separating the minima.
Analytical Treatment of Forecasts of Electric Energy Consumption in Latvia
NASA Astrophysics Data System (ADS)
Balodis, M.; Gavars, V.; Andersons, J.
2014-06-01
In the paper, the changes in electric energy consumption are analyzed as associated with structural changes in the Latvian economy of postsocialistic period. To the analysis, a particular approach is applied, which consists in comparison of the basic and specific electricity consumption indices in West-, Central-, and East-European states for the time span of 1990-2010, with differences and tendencies of changes revealed. Tendencies of the type are determined for the electric energy consumption in Latvia, and recommendations are given for the use of such indices in the relevant forecasts. Rakstā apskatītas elektroenerģijas patēriņa izmaiņas, kas saistītas ar Latvijas postsociālisma perioda ekonomikas strukturālām izmaiņām. Rakstā dota Latvijas galveno elektroenerģijas patēriņa indikatoru analīze, lietojot īpašu pieeju - Rietumeiropas, Centrāleiropas un Austrumeiropas valstu indikatoru salīdzinājumu. Analizēts periods no 1990. gada līdz 2010. gadam. Salīdzināti Eiropas valstu grupu īpatnējie elektroenerģijas patēriņa indikatori un noskaidrotas to atšķirības un izmaiņu tendences. Noteiktas elektroenerģijas patēriņa izmaiņu tendences Latvijā. Dotas rekomendācijas par šo indikatoru izmantošanu elektroenerģijas patēriņa prognozēšanā. 07.05.2014.
Nakajima, Yuya; Seino, Junji; Nakai, Hiromi
2013-12-28
In this study, the analytical energy gradient for the spin-free infinite-order Douglas-Kroll-Hess (IODKH) method at the levels of the Hartree-Fock (HF), density functional theory (DFT), and second-order Møller-Plesset perturbation theory (MP2) is developed. Furthermore, adopting the local unitary transformation (LUT) scheme for the IODKH method improves the efficiency in computation of the analytical energy gradient. Numerical assessments of the present gradient method are performed at the HF, DFT, and MP2 levels for the IODKH with and without the LUT scheme. The accuracies are examined for diatomic molecules such as hydrogen halides, halogen dimers, coinage metal (Cu, Ag, and Au) halides, and coinage metal dimers, and 20 metal complexes, including the fourth-sixth row transition metals. In addition, the efficiencies are investigated for one-, two-, and three-dimensional silver clusters. The numerical results confirm the accuracy and efficiency of the present method.
Fermi level stabilization energy in cadmium oxide
Speaks, D. T.; Mayer, M. A.; Yu, K. M.; Mao, S. S.; Haller, E. E.; Walukiewicz, W.
2010-04-08
We have studied the effects of high concentrations of native point defects on the electrical and optical properties of CdO. The defects were introduced by irradiation with high energy He+, Ne+, Ar+ and C+ ions. Increasing the irradiation damage with particles heavier than He+ increases the electron concentration until a saturation level of 5x1020 cm-3 is reached. In contrast, due to the ionic character and hence strong dynamic annealing of CdO, irradiation with much lighter He+ stabilizes the electron concentration at a much lower level of 1.7x1020 cm-3. A large shift of the optical absorption edge with increasing electron concentration in irradiated samples is explained by the Burstein-Moss shift corrected for electron-electron and electron-ion interactions. The saturation of the electron concentration and the optical absorption edge energy are consistent with a defect induced stabilization of the Fermi energy at 1 eV above the conduction band edge. The result is in a good agreement with previously determined Fermi level pinning energies on CdO surfaces. The results indicate that CdO shares many similarities with InN, as both materials exhibit extremely large electron affinities and an unprecedented propensity for n-type conductivity.
Analytical method for calculating neutron bulk shielding in a medium-energy accelerator facility
NASA Astrophysics Data System (ADS)
Kato, Takashi; Nakamura, Takashi
2001-05-01
This investigation aims at an analytical method for calculating neutron bulk shielding in a medium-energy accelerator facility on the basis of the modified Moyer model. Shielding parameters for the analytical formula are obtained using the ANISN one-dimensional discrete ordinate code and the MCNP three-dimensional Monte Carlo code. The dose attenuation length of a concrete shield, which is the most important parameter, is obtained as a function of neutron energies from 0.2 MeV to 400 MeV and of shield thickness from 1 m to 7 m. The equation is also applicable to the estimation of neutron oblique penetration through a concrete shield, so the correction factor for oblique penetration is introduced into the analytical formula. It is expressed as the ratio of dose equivalent as calculated with MCNP for penetration through a relatively thin (1 or 2 m thick) concrete slab shield to that with the analytical equation developed in this work.
Analytic expression for the energy-transfer rate from photoelectrons to thermal-electrons.
NASA Technical Reports Server (NTRS)
Swartz, W. E.; Nisbet, J. S.; Green, A. E. S.
1971-01-01
An analytic form is given for the energy-transfer rate from photoelectrons to thermal electrons. The expression fits the classical formulation of Itakawa and Aono (1966) at low energies and gives a smooth transition to fit the quantum mechanical equation of Schunk and Hays (1971) at higher energies. The corresponding loss function or stopping power has a form that is convenient in auroral and dayglow calculations.
A Bayesian Multi-Level Factor Analytic Model of Consumer Price Sensitivities across Categories
ERIC Educational Resources Information Center
Duvvuri, Sri Devi; Gruca, Thomas S.
2010-01-01
Identifying price sensitive consumers is an important problem in marketing. We develop a Bayesian multi-level factor analytic model of the covariation among household-level price sensitivities across product categories that are substitutes. Based on a multivariate probit model of category incidence, this framework also allows the researcher to…
A Bayesian Multi-Level Factor Analytic Model of Consumer Price Sensitivities across Categories
ERIC Educational Resources Information Center
Duvvuri, Sri Devi; Gruca, Thomas S.
2010-01-01
Identifying price sensitive consumers is an important problem in marketing. We develop a Bayesian multi-level factor analytic model of the covariation among household-level price sensitivities across product categories that are substitutes. Based on a multivariate probit model of category incidence, this framework also allows the researcher to…
The molecular potential energy surface and vibrational energy levels of methyl fluoride. Part II.
Manson, Steven A; Law, Mark M; Atkinson, Ian A; Thomson, Grant A
2006-06-28
New analytical bending and stretching, ground electronic state, potential energy surfaces for CH(3)F are reported. The surfaces are expressed in bond-length, bond-angle internal coordinates. The four-dimensional stretching surface is an accurate, least squares fit to over 2000 symmetrically unique ab initio points calculated at the CCSD(T) level. Similarly, the five-dimensional bending surface is a fit to over 1200 symmetrically unique ab initio points. This is an important first stage towards a full nine-dimensional potential energy surface for the prototype CH(3)F molecule. Using these surfaces, highly excited stretching and (separately) bending vibrational energy levels of CH(3)F are calculated variationally using a finite basis representation method. The method uses the exact vibrational kinetic energy operator derived for XY(3)Z systems by Manson and Law (preceding paper, Part I, Phys. Chem. Chem. Phys., 2006, 8, DOI: 10.1039/b603106d). We use the full C(3v) symmetry and the computer codes are designed to use an arbitrary potential energy function. Ultimately, these results will be used to design a compact basis for fully coupled stretch-bend calculations of the vibrational energy levels of the CH(3)F system.
Steering quantum transitions between three crossing energy levels
Ivanov, S. S.; Vitanov, N. V.
2008-02-15
We calculate the propagator and the transition probabilities for a coherently driven three-state quantum system. The energies of the three states change linearly in time, whereas the interactions between them are pulse shaped. We derive a highly accurate analytic approximation by assuming independent pairwise Landau-Zener transitions occurring instantly at the relevant avoided crossings, and adiabatic evolution elsewhere. Quantum interferences are identified, which occur due to different possible evolution paths in Hilbert space between an initial and a final state. A detailed comparison with numerical results for Gaussian-shaped pulses demonstrates a remarkable accuracy of the analytic approximation. We use the analytic results to derive estimates for the half-width of the excitation profile, and for the parameters required for creation of a maximally coherent superposition of the three states. These results are of potential interest in ladder climbing in alkali-metal atoms by chirped laser pulses, in quantum rotors, in transitions between Zeeman sublevels of a J=1 level in a magnetic field, and in control of entanglement of a pair of spin-1/2 particles. The results for the three-state system can be generalized, without essential difficulties, to higher dimensions.
Potential energy surface and rovibrational energy levels of the H2-CS van der Waals complex.
Denis-Alpizar, Otoniel; Stoecklin, Thierry; Halvick, Philippe; Dubernet, Marie-Lise; Marinakis, Sarantos
2012-12-21
Owing to its large dipole, astrophysicists use carbon monosulfide (CS) as a tracer of molecular gas in the interstellar medium, often in regions where H(2) is the most abundant collider. Predictions of the rovibrational energy levels of the weakly bound complex CS-H(2) (not yet observed) and also of rate coefficients for rotational transitions of CS in collision with H(2) should help to interpret the observed spectra. This paper deals with the first goal, i.e., the calculation of the rovibrational energy levels. A new four-dimensional intermolecular potential energy surface for the H(2)-CS complex is presented. Ab initio potential energy calculations were carried out at the coupled-cluster level with single and double excitations and a perturbative treatment of triple excitations, using a quadruple-zeta basis set and midbond functions. The potential energy surface was obtained by an analytic fit of the ab initio data. The equilibrium structure of the H(2)-CS complex is found to be linear with the carbon pointing toward H(2) at the intermolecular separation of 8.6 a(o). The corresponding well depth is -173 cm(-1). The potential was used to calculate the rovibrational energy levels of the para-H(2)-CS and ortho-H(2)-CS complexes. The present work provides the first theoretical predictions of these levels. The calculated dissociation energies are found to be 35.9 cm(-1) and 49.9 cm(-1), respectively, for the para and ortho complexes. The second virial coefficient for the H(2)-CS pair has also been calculated for a large range of temperature. These results could be used to assign future experimental spectra and to check the accuracy of the potential energy surface.
Analytic second derivatives of the energy in the fragment molecular orbital method.
Nakata, Hiroya; Nagata, Takeshi; Fedorov, Dmitri G; Yokojima, Satoshi; Kitaura, Kazuo; Nakamura, Shinichiro
2013-04-28
We developed the analytic second derivatives of the energy for the fragment molecular orbital (FMO) method. First we derived the analytic expressions and then introduced some approximations related to the first and second order coupled perturbed Hartree-Fock equations. We developed a parallel program for the FMO Hessian with approximations in GAMESS and used it to calculate infrared (IR) spectra and Gibbs free energies and to locate the transition states in SN2 reactions. The accuracy of the Hessian is demonstrated in comparison to ab initio results for polypeptides and a water cluster. By using the two residues per fragment division, we achieved the accuracy of 3 cm(-1) in the reduced mean square deviation of vibrational frequencies from ab initio for all three polyalanine isomers, while the zero point energy had the error not exceeding 0.3 kcal/mol. The role of the secondary structure on IR spectra, zero point energies, and Gibbs free energies is discussed.
Analytic second derivatives of the energy in the fragment molecular orbital method
NASA Astrophysics Data System (ADS)
Nakata, Hiroya; Nagata, Takeshi; Fedorov, Dmitri G.; Yokojima, Satoshi; Kitaura, Kazuo; Nakamura, Shinichiro
2013-04-01
We developed the analytic second derivatives of the energy for the fragment molecular orbital (FMO) method. First we derived the analytic expressions and then introduced some approximations related to the first and second order coupled perturbed Hartree-Fock equations. We developed a parallel program for the FMO Hessian with approximations in GAMESS and used it to calculate infrared (IR) spectra and Gibbs free energies and to locate the transition states in SN2 reactions. The accuracy of the Hessian is demonstrated in comparison to ab initio results for polypeptides and a water cluster. By using the two residues per fragment division, we achieved the accuracy of 3 cm-1 in the reduced mean square deviation of vibrational frequencies from ab initio for all three polyalanine isomers, while the zero point energy had the error not exceeding 0.3 kcal/mol. The role of the secondary structure on IR spectra, zero point energies, and Gibbs free energies is discussed.
Spectrum and energy levels of Mo VI
NASA Astrophysics Data System (ADS)
Reader, Joseph
1998-05-01
We have photographed the spectrum of the Rb-like ion Mo VI from 200 to 5300 Å with a sliding-spark discharge on our 10.7-m normal- and grazing-incidence spectrographs and have observed most of the yrast transitions given by Romanov et al.(N. P. Romanov and A. R. Striganov, Opt. Spectrosc. 27), 8 (1969). from a Penning discharge. We have obtained improved values for all of the energy levels. We confirm the odd levels of Kancerevicius et al.,(A. Kancerevicius et al.), Lithuanian Phys. J. 31, 143 (1991). but have revised a number of the even levels of Edlén et al.(B. Edlén et al.), Phys. Scr. 32, 215 (1985). The ionization energy of Edlén et al.,footnotemark[4] which had been called into question by Kancerevicius et al.footnotemark[3] as a result of their revision of the odd levels,footnotemark[4] is confirmed.
Nonequivalent lanthanide defects: Energy level modeling
NASA Astrophysics Data System (ADS)
Joos, Jonas J.; Poelman, Dirk; Smet, Philippe F.
2016-11-01
Empirical charge-state transition level schemes are popular tools to model the properties of lanthanide-doped materials and their construction has become standard practice. Typically, it is implicitly assumed that all lanthanide ions form isostructural defects. However, in practice, multiple nonequivalent defects related to the same lanthanide can occur or different lanthanides can even incorporate in different ways. The consequences of these complications on the impurity energy levels are discussed in this article. It seems that small structural differences around the lanthanide dopant can give rise to important spectral differences in its emission. These are not always clearly reproduced by the charge-state transition level schemes. Improvements to the existing procedure are suggested and applied to the lanthanide ions in the well-studied host crystals SrAl2O4, Sr2Si5N8 and SrGa2S4.
Energy-level alignment at organic heterointerfaces
Oehzelt, Martin; Akaike, Kouki; Koch, Norbert; Heimel, Georg
2015-01-01
Today’s champion organic (opto-)electronic devices comprise an ever-increasing number of different organic-semiconductor layers. The functionality of these complex heterostructures largely derives from the relative alignment of the frontier molecular-orbital energies in each layer with respect to those in all others. Despite the technological relevance of the energy-level alignment at organic heterointerfaces, and despite continued scientific interest, a reliable model that can quantitatively predict the full range of phenomena observed at such interfaces is notably absent. We identify the limitations of previous attempts to formulate such a model and highlight inconsistencies in the interpretation of the experimental data they were based on. We then develop a theoretical framework, which we demonstrate to accurately reproduce experiment. Applying this theory, a comprehensive overview of all possible energy-level alignment scenarios that can be encountered at organic heterojunctions is finally given. These results will help focus future efforts on developing functional organic interfaces for superior device performance. PMID:26702447
Analytical model of ionization and energy deposition by proton beams in subcellular compartments
NASA Astrophysics Data System (ADS)
de Vera, Pablo; Surdutovich, Eugene; Abril, Isabel; Garcia-Molina, Rafael; Solov'yov, Andrey V.
2014-04-01
We present an analytical model to evaluate in a fast, simple and effective manner the energy delivered by proton beams moving through a cell model made of nucleus and cytoplasm, taking into account the energy carried by the secondary electrons generated along the proton tracks. The electronic excitation spectra of these subcellular compartments have been modelled by means of an empirical parameterization of their dielectric properties. The energy loss rate and target ionization probability induced by swift protons are evaluated by means of the dielectric formalism. With the present model we have quantified the energy delivered, the specific energy, and the number of ionizations produced per incoming ion in a typical human cell by a typical hadrontherapy proton beam having energies usually reached around the Bragg peak (below 20 MeV). We find that the specific energy per incoming ion delivered in the nucleus and in the cytoplasm are rather similar for all the proton energy range analyzed.
Analytical solution and optimal design for galloping-based piezoelectric energy harvesters
NASA Astrophysics Data System (ADS)
Tan, T.; Yan, Z.
2016-12-01
The performance of the galloping-based piezoelectric energy harvester is usually investigated numerically. Instead of performing case studies by numerical simulations, analytical solutions of the nonlinear distributed parameter model are derived to capture the intrinsic effects of the physical parameters on the performance of such energy harvesters. The analytical solutions are confirmed with the numerical solutions. Optimal performance of such energy harvesters is therefore revealed theoretically. The electric damping due to the electromechanical coupling is defined. The design at the optimal electrical damping with smaller onset speed to galloping, higher harvested power, and acceptable tip displacement is superior than the design at the maximal electrical damping, as long as the optimal electrical damping can be achieved. Otherwise, the design at the maximal electrical damping should be then adopted. As the wind speed and aerodynamic empirical coefficients increase, the tip displacement and harvested power increase. This study provides a theoretical design and optimization procedure for galloping-based piezoelectric energy harvesters.
Analytical sensitivities and energies of thermal neutron capture gamma rays II
Senftle, F.E.; Moore, H.D.; Leep, D.B.; El-Kady, A.; Duffey, D.
1971-01-01
A table of the analytical sensitivities of the principal lines in the thermal neutron capture gamma-ray spectrum from 0 to 3 MeV has been compiled for most of the elements. A tabulation of the full-energy, single-escape, and double-escape peaks has also been made according to energy. The tables are useful for spectral interpretation and calibration. ?? 1971.
Analytical sensitivities and energies of thermal-neutron-capture gamma rays
Duffey, D.; El-Kady, A.; Senftle, F.E.
1970-01-01
A table of the analytical sensitivities of the principal lines in the thermal-neutron-capture gamma ray spectrum has been compiled for most of the elements. In addition a second table of the full-energy, single-escape, and double-escape peaks has been compiled according to energy for all significant lines above 3 MeV. Lines that contrast well with adjacent lines are noted as prominent. The tables are useful for spectral interpretation and calibration. ?? 1970.
Review of Analytes of Concern and Sample Methods for Closure of DOE High Level Waste Storage Tanks
Thomas, T.R.
2002-05-06
Sampling residual waste after tank cleaning and analysis for analytes of concern to support closure and cleaning targets of large underground tanks used for storage of legacy high level radioactive waste (HLW) at Department of Energy (DOE) sites has been underway since about 1995. The DOE Tanks Focus Area (TFA) has been working with DOE tank sites to develop new sampling plans, and sampling methods for assessment of residual waste inventories. This paper discusses regulatory analytes of concern, sampling plans, and sampling methods that support closure and cleaning target activities for large storage tanks at the Hanford Site, the Savannah River Site (SRS), the Idaho National Engineering and Environmental Laboratory (INEEL), and the West Valley Demonstration Project (WVDP).
Review of Analytes of Concern and Sample Methods for Closure of DOE High Level Waste Storage Tanks
Thomas, Thomas Russell
2002-08-01
Sampling residual waste after tank cleaning and analysis for analytes of concern to support closure and cleaning targets of large underground tanks used for storage of legacy high level radioactive waste (HLW) at Department of Energy (DOE) sites has been underway since about 1995. The DOE Tanks Focus Area (TFA) has been working with DOE tank sites to develop new sampling plans, and sampling methods for assessment of residual waste inventories. This paper discusses regulatory analytes of concern, sampling plans, and sampling methods that support closure and cleaning target activities for large storage tanks at the Hanford Site, the Savannah River Site (SRS), the Idaho National Engineering and Environmental Laboratory (INEEL), and the West Valley Demonstration Project (WVDP).
21 CFR 530.40 - Safe levels and availability of analytical methods.
Code of Federal Regulations, 2012 CFR
2012-04-01
.... 530.40 Section 530.40 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... for Extralabel Use of Drugs in Animals and Drugs Prohibited From Extralabel Use in Animals § 530.40 Safe levels and availability of analytical methods. (a) In accordance with § 530.22, the following safe...
The vibrational energy levels of ammonia
NASA Astrophysics Data System (ADS)
Handy, Nicholas C.
1999-02-01
A variational 6-dimensional method is used to determine the low lying vibrational energy levels of ammonia. The six internal coordinates were chosen to be appropriate for the symmetry and inversion motion of the molecule; they were the three NH bond lengths, r1,r2,r3, the unique angle beta which each bond makes with the trisector of them, and two (of the three) angles, theta2 and theta3, between the bonds when projected on to a plane perpendicular to the trisector. The Wilson G matrix was determined for these internal coordinates both by computer algebra and by hand. An appropriate Jacobian for the motion was determined and the full Hermitian kinetic energy operator was obtained using the Podolsky transformation. Expansion functions were in the usual product form. Special attention was given to the , theta2,theta3 expansion functions so that appropriate A1,A2 and E symmetry vibrational modes were obtained explicitly. Matrix elements of the kinetic energy operator were expressed in terms of one-dimensional integrals. Variational calculations have been performed with two six-dimensional surfaces: (i) that due to Martin, Lee and Taylor; and (ii) that due to Spirko and Kraemer. Although some of the vibrational levels for both surfaces are accurate, both have inadequacies: (a) because it is a Taylor expansion about an equilibrium, based on ab initio calculations, with no attention paid to planarity; and (b) because the non-inversion part of the surface was treated perturbatively in its derivation, and in fact some of the quartic displacement powers have negative coefficients. Therefore, neither surface gave good results overall, and there is a need for a refined 6 dimensional NH surface.
Analytic model of energy-absorption response functions in compound X-ray detector materials.
Yun, Seungman; Kim, Ho Kyung; Youn, Hanbean; Tanguay, Jesse; Cunningham, Ian A
2013-10-01
The absorbed energy distribution (AED) in X-ray imaging detectors is an important factor that affects both energy resolution and image quality through the Swank factor and detective quantum efficiency. In the diagnostic energy range (20-140 keV), escape of characteristic photons following photoelectric absorption and Compton scatter photons are primary sources of absorbed-energy dispersion in X-ray detectors. In this paper, we describe the development of an analytic model of the AED in compound X-ray detector materials, based on the cascaded-systems approach, that includes the effects of escape and reabsorption of characteristic and Compton-scatter photons. We derive analytic expressions for both semi-infinite slab and pixel geometries and validate our approach by Monte Carlo simulations. The analytic model provides the energy-dependent X-ray response function of arbitrary compound materials without time-consuming Monte Carlo simulations. We believe this model will be useful for correcting spectral distortion artifacts commonly observed in photon-counting applications and optimal design and development of novel X-ray detectors.
NASA Astrophysics Data System (ADS)
Gorostiaga, M.; Wapler, M. C.; Wallrabe, U.
2017-10-01
In this paper, we verify the two optimal electric load concepts based on the zero reflection condition and on the power maximization approach for ultrasound energy receivers. We test a high loss 1–3 composite transducer, and find that the measurements agree very well with the predictions of the analytic model for plate transducers that we have developed previously. Additionally, we also confirm that the power maximization and zero reflection loads are very different when the losses in the receiver are high. Finally, we compare the optimal load predictions by the KLM and the analytic models with frequency dependent attenuation to evaluate the influence of the viscosity.
NASA Technical Reports Server (NTRS)
Phatak, A. V.
1980-01-01
A systematic analytical approach to the determination of helicopter IFR precision approach requirements is formulated. The approach is based upon the hypothesis that pilot acceptance level or opinion rating of a given system is inversely related to the degree of pilot involvement in the control task. A nonlinear simulation of the helicopter approach to landing task incorporating appropriate models for UH-1H aircraft, the environmental disturbances and the human pilot was developed as a tool for evaluating the pilot acceptance hypothesis. The simulated pilot model is generic in nature and includes analytical representation of the human information acquisition, processing, and control strategies. Simulation analyses in the flight director mode indicate that the pilot model used is reasonable. Results of the simulation are used to identify candidate pilot workload metrics and to test the well known performance-work-load relationship. A pilot acceptance analytical methodology is formulated as a basis for further investigation, development and validation.
Analytical design of a superconducting magnetic energy storage for pulsed power peak
Netter, D.; Leveque, J.; Rezzoug, A.; Caron, J.P.; Sargos, F.M.
1996-09-01
A Superconducting Magnetic Energy Storage can be used to produce very high pulsed power peak. A superconducting coil is magnetically coupled with another coil linked to the load. During the storage phase, the current is constant. In order to transfer the energy to the load, the authors cause the quench of the superconducting coil. It is very important to know the efficiency of the transfer and how much energy is discharged in the Helium vessel. In this paper, they propose an analytical method which enables to calculate very quickly the electrical parameters of such a device.
NASA Astrophysics Data System (ADS)
Mamedov, Bahtiyar Akber; Copuroglu, Ebru
2017-02-01
By using the Löwdin-α function method, we have analytically calculated the two-center kinetic energy integrals over Slater type orbitals (STOs). The two-center kinetic energy integrals are presented in terms of the two-center overlap integrals. A new approach is applicable to accurate calculations of two-center kinetic energy integral over STOs for arbitrary values of scaling parameters and interatomic distances. Obtained results show that the proposed method is easy to apply to the real systems, and has better calculation CPU time with compared to the existing approximations.
ERIC Educational Resources Information Center
Toh, Chee-Seng
2007-01-01
A project is described which incorporates nonlaboratory research skills in a graduate level course on analytical chemistry. This project will help students to grasp the basic principles and concepts of modern analytical techniques and also help them develop relevant research skills in analytical chemistry.
ERIC Educational Resources Information Center
Toh, Chee-Seng
2007-01-01
A project is described which incorporates nonlaboratory research skills in a graduate level course on analytical chemistry. This project will help students to grasp the basic principles and concepts of modern analytical techniques and also help them develop relevant research skills in analytical chemistry.
An analytic solution to the Förster energy transfer problem in two dimensions.
Wolber, P K; Hudson, B S
1979-01-01
An analytic solution of the Förster energy transfer problem in two dimensions is presented for the case in which the orientation factor is independent of the donor-acceptor distance, and both the donors and acceptors are randomly distributed in a plane. A general solution based on the method of Förster is possible since all distances are measured in units of R0. The analytic solution is extended to the cases of donors embedded in structures that exclude acceptors, and donors that bind acceptors. The validity of the analytic solutions is demonstrated by comparison with numerical simulation calculations. Numerical approximations to the exact solutions are given for ease of computation. Specific applications to the case of fluorescence quenching of a membrane-bound donor by membrane-bound acceptors are presented. PMID:262548
NASA Technical Reports Server (NTRS)
Schwenke, David W.; Walch, Stephen P.; Taylor, Peter R.
1991-01-01
Extensive ab initio calculations on the ground state potential energy surface of H2 + H2O were performed using a large contracted Gaussian basis set and a high level of correlation treatment. An analytical representation of the potential energy surface was then obtained which reproduces the calculated energies with an overall root-mean-square error of only 0.64 mEh. The analytic representation explicitly includes all nine internal degrees of freedom and is also well behaved as the H2 dissociates; it thus can be used to study collision-induced dissociation or recombination of H2. The strategy used to minimize the number of energy calculations is discussed, as well as other advantages of the present method for determining the analytical representation.
NASA Technical Reports Server (NTRS)
Schwenke, David W.; Walch, Stephen P.; Taylor, Peter R.
1991-01-01
Extensive ab initio calculations on the ground state potential energy surface of H2 + H2O were performed using a large contracted Gaussian basis set and a high level of correlation treatment. An analytical representation of the potential energy surface was then obtained which reproduces the calculated energies with an overall root-mean-square error of only 0.64 mEh. The analytic representation explicitly includes all nine internal degrees of freedom and is also well behaved as the H2 dissociates; it thus can be used to study collision-induced dissociation or recombination of H2. The strategy used to minimize the number of energy calculations is discussed, as well as other advantages of the present method for determining the analytical representation.
Angioletti-Uberti, Stefano; Varilly, Patrick; Mognetti, Bortolo M; Tkachenko, Alexei V; Frenkel, Daan
2013-01-14
Recently [P. Varilly, S. Angioletti-Uberti, B. M. Mognetti, and D. Frenkel, "A general theory of DNA-mediated and other valence-limited colloidal interactions," J. Chem. Phys. 137, 094108 (2012)], we presented a general theory for calculating the strength and properties of colloidal interactions mediated by ligand-receptor bonds (such as those that bind DNA-coated colloids). In this Communication, we derive a surprisingly simple analytical form for the interaction free energy, which was previously obtainable only via a costly numerical thermodynamic integration. As a result, the computational effort to obtain potentials of interaction is significantly reduced. Moreover, we can gain insight from this analytic expression for the free energy in limiting cases. In particular, the connection of our general theory to other previous specialised approaches is now made transparent. This important simplification will significantly broaden the scope of our theory.
NASA Astrophysics Data System (ADS)
Yang, Wei; Dong, Zhiwei
2016-01-01
This paper investigates the electron-vibrational (e-V) energy exchange in nitrogen-containing plasma, which is very efficient in the case of gas discharge and high speed flow. Based on Harmonic oscillator approximation and the assumption of the e-V relaxation through a continuous series of Boltzmann distributions over the vibrational states, an analytic approach is derived from the proposed scaling relation of e-V transition rates. A full kinetic model is then investigated by numerically solving the state-to-state master equation for all vibrational levels. The analytical approach leads to a Landau-Teller (LT)-type equation for relaxation of vibrational energy, and predicts the relaxation time on the right order of magnitude. By comparison with the kinetic model, the LT-type equation is valid in typical electron temperatures in gas discharge. However, the analytical approach is not capable of describing the vibrational distribution function during the e-V process in which a full kinetic model is required. supported by National Natural Science Foundation of China (No. 11505015) and the National High-Tech Research and Development Program of China (863 Program)
Measuring energy metabolism in the mouse - theoretical, practical, and analytical considerations.
Speakman, John R
2013-01-01
The mouse is one of the most important model organisms for understanding human genetic function and disease. This includes characterization of the factors that influence energy expenditure and dysregulation of energy balance leading to obesity and its sequelae. Measuring energy metabolism in the mouse presents a challenge because the animals are small, and in this respect it presents similar challenges to measuring energy demands in many other species of small mammal. This paper considers some theoretical, practical, and analytical considerations to be considered when measuring energy expenditure in mice. Theoretically total daily energy expenditure is comprised of several different components: basal or resting expenditure, physical activity, thermoregulation, and the thermic effect of food. Energy expenditure in mice is normally measured using open flow indirect calorimetry apparatus. Two types of system are available - one of which involves a single small Spartan chamber linked to a single analyzer, which is ideal for measuring the individual components of energy demand. The other type of system involves a large chamber which mimics the home cage environment and is generally configured with several chambers/analyzer. These latter systems are ideal for measuring total daily energy expenditure but at present do not allow accurate decomposition of the total expenditure into its components. The greatest analytical challenge for mouse expenditure data is how to account for body size differences between individuals. This has been a matter of some discussion for at least 120 years. The statistically most appropriate approach is to use analysis of covariance with individual aspects of body composition as independent predictors.
Measuring Energy Metabolism in the Mouse – Theoretical, Practical, and Analytical Considerations
Speakman, John R.
2012-01-01
The mouse is one of the most important model organisms for understanding human genetic function and disease. This includes characterization of the factors that influence energy expenditure and dysregulation of energy balance leading to obesity and its sequelae. Measuring energy metabolism in the mouse presents a challenge because the animals are small, and in this respect it presents similar challenges to measuring energy demands in many other species of small mammal. This paper considers some theoretical, practical, and analytical considerations to be considered when measuring energy expenditure in mice. Theoretically total daily energy expenditure is comprised of several different components: basal or resting expenditure, physical activity, thermoregulation, and the thermic effect of food. Energy expenditure in mice is normally measured using open flow indirect calorimetry apparatus. Two types of system are available – one of which involves a single small Spartan chamber linked to a single analyzer, which is ideal for measuring the individual components of energy demand. The other type of system involves a large chamber which mimics the home cage environment and is generally configured with several chambers/analyzer. These latter systems are ideal for measuring total daily energy expenditure but at present do not allow accurate decomposition of the total expenditure into its components. The greatest analytical challenge for mouse expenditure data is how to account for body size differences between individuals. This has been a matter of some discussion for at least 120 years. The statistically most appropriate approach is to use analysis of covariance with individual aspects of body composition as independent predictors. PMID:23504620
Analytical model for self-energy operators and exchange-correlation potentials in non-metals
NASA Astrophysics Data System (ADS)
W, Hanke; Sham, L. J.
1989-07-01
We obtain a simple, analytical and yet accurate description of both ground- and excited-state properties from a tight-binding calculation of (i) the self-energy (ii) the density-functional (DF) exchange-correlation potential, and (iii) the band-gap correction to the one-particle DF eigenvalues. The model self-energy results are to within a few percent of recent first-principles numerical data for diamond, Si and LiCl. The new ground-state potential provides insight into the validity of the local-density approximation in non-metals, in general.
NASA Astrophysics Data System (ADS)
Hilpert, M.; Long, W.
2007-12-01
Motile bacteria may form bands that travel with a constant speed of propagation through a medium containing a dissolved substrate, to which they respond energy tactically. We generalize the analytical solution by Keller and Segel for such bands by accounting for (1) the presence of a porous medium, (2) substrate consumption described by a Monod kinetics model, and (3) an energy tactic response model derived by Rivero et al. We also comment on the potential role of traveling bacterial bands in the remediation of groundwater contamination.
Dias, Frédéric; Renzi, Emiliano; Gallagher, Sarah; Sarkar, Dripta; Wei, Yanji; Abadie, Thomas; Cummins, Cathal; Rafiee, Ashkan
2017-01-01
The development of new wave energy converters has shed light on a number of unanswered questions in fluid mechanics, but has also identified a number of new issues of importance for their future deployment. The main concerns relevant to the practical use of wave energy converters are sustainability, survivability, and maintainability. Of course, it is also necessary to maximize the capture per unit area of the structure as well as to minimize the cost. In this review, we consider some of the questions related to the topics of sustainability, survivability, and maintenance access, with respect to sea conditions, for generic wave energy converters with an emphasis on the oscillating wave surge converter. New analytical models that have been developed are a topic of particular discussion. It is also shown how existing numerical models have been pushed to their limits to provide answers to open questions relating to the operation and characteristics of wave energy converters.
NASA Astrophysics Data System (ADS)
Dias, Frédéric; Renzi, Emiliano; Gallagher, Sarah; Sarkar, Dripta; Wei, Yanji; Abadie, Thomas; Cummins, Cathal; Rafiee, Ashkan
2017-08-01
The development of new wave energy converters has shed light on a number of unanswered questions in fluid mechanics, but has also identified a number of new issues of importance for their future deployment. The main concerns relevant to the practical use of wave energy converters are sustainability, survivability, and maintainability. Of course, it is also necessary to maximize the capture per unit area of the structure as well as to minimize the cost. In this review, we consider some of the questions related to the topics of sustainability, survivability, and maintenance access, with respect to sea conditions, for generic wave energy converters with an emphasis on the oscillating wave surge converter. New analytical models that have been developed are a topic of particular discussion. It is also shown how existing numerical models have been pushed to their limits to provide answers to open questions relating to the operation and characteristics of wave energy converters.
Sanchez-Parcerisa, D; Cortés-Giraldo, M A; Dolney, D; Kondrla, M; Fager, M; Carabe, A
2016-02-21
In order to integrate radiobiological modelling with clinical treatment planning for proton radiotherapy, we extended our in-house treatment planning system FoCa with a 3D analytical algorithm to calculate linear energy transfer (LET) in voxelized patient geometries. Both active scanning and passive scattering delivery modalities are supported. The analytical calculation is much faster than the Monte-Carlo (MC) method and it can be implemented in the inverse treatment planning optimization suite, allowing us to create LET-based objectives in inverse planning. The LET was calculated by combining a 1D analytical approach including a novel correction for secondary protons with pencil-beam type LET-kernels. Then, these LET kernels were inserted into the proton-convolution-superposition algorithm in FoCa. The analytical LET distributions were benchmarked against MC simulations carried out in Geant4. A cohort of simple phantom and patient plans representing a wide variety of sites (prostate, lung, brain, head and neck) was selected. The calculation algorithm was able to reproduce the MC LET to within 6% (1 standard deviation) for low-LET areas (under 1.7 keV μm(-1)) and within 22% for the high-LET areas above that threshold. The dose and LET distributions can be further extended, using radiobiological models, to include radiobiological effectiveness (RBE) calculations in the treatment planning system. This implementation also allows for radiobiological optimization of treatments by including RBE-weighted dose constraints in the inverse treatment planning process.
NASA Astrophysics Data System (ADS)
Sanchez-Parcerisa, D.; Cortés-Giraldo, M. A.; Dolney, D.; Kondrla, M.; Fager, M.; Carabe, A.
2016-02-01
In order to integrate radiobiological modelling with clinical treatment planning for proton radiotherapy, we extended our in-house treatment planning system FoCa with a 3D analytical algorithm to calculate linear energy transfer (LET) in voxelized patient geometries. Both active scanning and passive scattering delivery modalities are supported. The analytical calculation is much faster than the Monte-Carlo (MC) method and it can be implemented in the inverse treatment planning optimization suite, allowing us to create LET-based objectives in inverse planning. The LET was calculated by combining a 1D analytical approach including a novel correction for secondary protons with pencil-beam type LET-kernels. Then, these LET kernels were inserted into the proton-convolution-superposition algorithm in FoCa. The analytical LET distributions were benchmarked against MC simulations carried out in Geant4. A cohort of simple phantom and patient plans representing a wide variety of sites (prostate, lung, brain, head and neck) was selected. The calculation algorithm was able to reproduce the MC LET to within 6% (1 standard deviation) for low-LET areas (under 1.7 keV μm-1) and within 22% for the high-LET areas above that threshold. The dose and LET distributions can be further extended, using radiobiological models, to include radiobiological effectiveness (RBE) calculations in the treatment planning system. This implementation also allows for radiobiological optimization of treatments by including RBE-weighted dose constraints in the inverse treatment planning process.
Analytical and empirical evaluation of low-level waste drum response to accident environments
May, R. A.; Romesberg, L. E.; Yoshimura, H. R.; Baker, W. E.; Hokanson, J. C.
1980-01-01
Based on results of tests to date, it was found that the structural response of low-level waste drums to impact environments can be generally predicted, both analytically and with subscale models. As currently represented, only the 1/4 scale models would adequately represent full scale drum deformation; however, additional work has shown that with proper heat treating the strength of the material used in the 1/8 scale containers can be reduced to the correct value. Both analytical models give results that are expected to be within the range of behavior of the full scale drums. Failure of the drum closure can be adequately inferred from the radial deformation results of both subscale tests and computer analyses. 6 figures.
Analytical modeling of a hydraulically-compensated compressed-air energy-storage system
McMonagle, C.A.; Rowe, D.S.
1982-12-01
A computer program was developed to calculate the dynamic response of a hydraulically-compensated compressed air energy storage (CAES) system, including the compressor, air pipe, cavern, and hydraulic compensation pipe. The model is theoretically based on the two-fluid model in which the dynamics of each phase are presented by its set of conservation equations for mass and momentum. The conservation equations define the space and time distribution of pressure, void fraction, air saturation, and phase velocities. The phases are coupled by two interface equations. The first defines the rate of generation (or dissolution) of gaseous air in water and can include the effects of supersaturation. The second defines the frictional shear coupling (drag) between the gaseous air and water as they move relative to each other. The relative motion of the air and water is, therefore, calculated and not specified by a slip or drift-velocity correlation. The total CASE system is represented by a nodal arrangement. The conservation equations are written for each nodal volume and are solved numerically. System boundary conditions include the air flow rate, atmospheric pressure at the top of the compensation pipe, and air saturation in the reservoir. Initial conditions are selected for velocity and air saturation. Uniform and constant temperature (60/sup 0/F) is assumed. The analytical model was used to investigate the dynamic response of a proposed system.Investigative calculations considered high and low water levels, and a variety of charging and operating conditions. For all cases investigated, the cavern response to air-charging, was a damped oscillation of pressure and flow. Detailed results are presented. These calculations indicate that the Champagne Effect is unlikely to cause blowout for a properly designed CAES system.
Győrffy, Werner; Shiozaki, Toru; Knizia, Gerald; Werner, Hans-Joachim
2013-03-14
We present algorithms for computing analytical energy gradients for multi-configuration self-consistent field methods and partially internally contracted complete active space second-order perturbation theory (CASPT2) using density fitting (DF). Our implementation is applicable to both single-state and multi-state CASPT2 analytical gradients. The accuracy of the new methods is demonstrated for structures and excitation energies of valence and Rydberg states of pyrrole, as well as for structures and adiabatic singlet-triplet energy splittings for the hydro-, the O,O(')-formato-, and the N,N(')-diiminato-copper-dioxygen complexes. It is shown that the effects of density fitting on optimized structures and relative energies are negligible. For cases in which the total cost is dominated by the integral evaluations and transformations, the DF-CASPT2 gradient calculations are found to be faster than the corresponding conventional calculations by typically a factor of three to five using triple-ζ basis sets, and by about a factor of ten using quadruple-ζ basis sets.
Lee, T.J.; Handy, N.C.; Rice, J.E.; Scheiner, A.C.; Schaefer H.F. III
1986-10-01
We present an efficient reformulation of the analytic configuration interaction (CI) energy second derivative. Specifically, the Z-vector method of Handy and Schaefer is used to avoid solving the second order coupled perturbed Hartree--Fock (CPHF) equations. We have incorporated translational--rotational invariance into the new method. We present a more efficient method for the evaluation of the Y matrix contribution. The procedure which has been implemented can accommodate very large basis sets and CI expansions for any general restricted Hartree--Fock (RHF) reference wave function. As a test case, we apply the new procedure to the HSOH molecule using a double zeta plus polarization basis set. This leads to 50 contracted Gaussian basis functions and 116 403 configurations in the CI expansion. Harmonic vibrational frequencies and infrared intensities are predicted for HSOH and its deuterated isotopomers. The analytic method described herein requires only 56% of the central processor unit time used by a numerical method.
NASA Astrophysics Data System (ADS)
Lee, Timothy J.; Handy, Nicholas C.; Rice, Julia E.; Scheiner, Andrew C.; Schaefer, Henry F., III
1986-10-01
We present an efficient reformulation of the analytic configuration interaction (CI) energy second derivative. Specifically, the Z-vector method of Handy and Schaefer is used to avoid solving the second order coupled perturbed Hartree-Fock (CPHF) equations. We have incorporated translational-rotational invariance into the new method. We present a more efficient method for the evaluation of the Y matrix contribution. The procedure which has been implemented can accommodate very large basis sets and CI expansions for any general restricted Hartree-Fock (RHF) reference wave function. As a test case, we apply the new procedure to the HSOH molecule using a double zeta plus polarization basis set. This leads to 50 contracted Gaussian basis functions and 116 403 configurations in the CI expansion. Harmonic vibrational frequencies and infrared intensities are predicted for HSOH and its deuterated isotopomers. The analytic method described herein requires only 56% of the central processor unit time used by a numerical method.
Automated computer-analytical system for ensuring reliability and safety of energy projects
Vasilevskii, A.G.; Serkov, V.S.; Dobrynin, S.N.; Tikhonova, T.S.
1995-09-01
This article discusses the development of a data bank system at the B. E. Vedeneev VNIIG Institute. The system consists of as many as 10 interacting data banks, most of which have been tested under field conditions. A brief discription is provided for each of the following data bases: (1) Certified parameters of Hydroelectric Plants of the world, (2) Certified parameters for thermoelectric plants in Russia, (3) Technical parameters of cooler-reservoirs of thermoelectric plants of Russia, (4) Equipment data bank for hydroelctric plants, (5) Information-analytical system of collection, storage, and processing of field observations, (6) World-wide data bank for the failure of hydroelectric plants, (7) Data bank for normative-technical documentation, (8) Data bank for normative-technical documentation of the operation of both hydro and thermal energy projects, (9) Data bank for documentation on anticorrosion protection of energy equipment, and (10) Data bank for scientific-technical achievements in the energy branch.
NASA Astrophysics Data System (ADS)
Dutta, Ranojoy
The ability to design high performance buildings has acquired great importance in recent years due to numerous federal, societal and environmental initiatives. However, this endeavor is much more demanding in terms of designer expertise and time. It requires a whole new level of synergy between automated performance prediction with the human capabilities to perceive, evaluate and ultimately select a suitable solution. While performance prediction can be highly automated through the use of computers, performance evaluation cannot, unless it is with respect to a single criterion. The need to address multi-criteria requirements makes it more valuable for a designer to know the "latitude" or "degrees of freedom" he has in changing certain design variables while achieving preset criteria such as energy performance, life cycle cost, environmental impacts etc. This requirement can be met by a decision support framework based on near-optimal "satisficing" as opposed to purely optimal decision making techniques. Currently, such a comprehensive design framework is lacking, which is the basis for undertaking this research. The primary objective of this research is to facilitate a complementary relationship between designers and computers for Multi-Criterion Decision Making (MCDM) during high performance building design. It is based on the application of Monte Carlo approaches to create a database of solutions using deterministic whole building energy simulations, along with data mining methods to rank variable importance and reduce the multi-dimensionality of the problem. A novel interactive visualization approach is then proposed which uses regression based models to create dynamic interplays of how varying these important variables affect the multiple criteria, while providing a visual range or band of variation of the different design parameters. The MCDM process has been incorporated into an alternative methodology for high performance building design referred to as
Lee, Chang Young; Strano, Michael S
2008-02-06
A wide range of analytes adsorb irreversibly to the surfaces of single walled carbon nanotube electronic networks typically used as sensors or thin-film transistors, although to date, the mechanism is not understood. Using thionyl chloride as a model electron-withdrawing adsorbate, we show that reversible adsorption sites can be created on the nanotube array via noncovalent functionalization with amine-terminated molecules of pKa < 8.8. A nanotube network comprising single, largely unbundled nanotubes, near the electronic percolation threshold is required for the effective conversion to a reversibly binding array. By examining 11 types of amine-containing molecules, we show that analyte adsorption is largely affected by the basicity (pKb) of surface groups. The binding energy of the analyte is apparently reduced by its adsorption on the surface chemical groups instead of directly on the SWNT array itself. This mediated adsorption mechanism is supported by X-ray photoelectron spectroscopy (XPS) and molecular potential calculations. Reversible detection with no active regeneration at the parts-per-trillion level is demonstrated for the first time by creating a higher adsorption site density with a polymer amine, such as polyethyleneimine (PEI). Last, we demonstrate that this transition to reversibility upon surface functionalization is a general phenomenon.
An analytical hierarchy process for decision making of high-level-waste management
Wang, J.H.C.; Jang, W.
1995-12-01
To prove the existence value of nuclear technology for the world of post cold war, demonstration of safe rad-waste disposal is essential. High-level-waste (HLW) certainly is the key issue to be resolved. To assist a rational and persuasive process on various disposal options, an Analytical Hierarchy Process (AHP) for the decision making of HLW management is presented. The basic theory and rationale are discussed, and applications are shown to illustrate the usefulness of the AHP. The authors wish that the AHP can provide a better direction for the current doomed situations of Taiwan nuclear industry, and to exchange with other countries for sharing experiences on the HLW management.
Leveraging Smart Meter Data through Advanced Analytics: Applications to Building Energy Efficiency
NASA Astrophysics Data System (ADS)
Jalori, Saurabh
The poor energy efficiency of buildings is a major barrier to alleviating the energy dilemma. Historically, monthly utility billing data was widely available and analytical methods for identifying building energy efficiency improvements, performing building Monitoring and Verification (M&V) and continuous commissioning (CCx) were based on them. Although robust, these methods were not sensitive enough to detect a number of common causes for increased energy use. In recent years, prevalence of short-term building energy consumption data, also known as Energy Interval Data (EID), made available through the Smart Meters, along with data mining techniques presents the potential of knowledge discovery inherent in this data. This allows more sophisticated analytical tools to be developed resulting in greater sensitivities due to higher prediction accuracies; leading to deep energy savings and highly efficient building system operations. The research explores enhancements to Inverse Statistical Modeling techniques due to the availability of EID. Inverse statistical modeling is the process of identification of prediction model structure and estimates of model parameters. The methodology is based on several common statistical and data mining techniques: cluster analysis for day typing, outlier detection and removal, and generation of building scheduling. Inverse methods are simpler to develop and require fewer inputs for model identification. They can model changes in energy consumption based on changes in climatic variables and up to a certain extent, occupancy. This makes them easy-to-use and appealing to building managers for evaluating any general retrofits, building condition monitoring, continuous commissioning and short-term load forecasting (STLF). After evaluating several model structures, an elegant model form was derived which can be used to model daily energy consumption; which can be extended to model energy consumption for any specific hour by adding corrective
You, Yang; Yang, Chuan-Lu; Wang, Mei-Shan; Ma, Xiao-Guang; Liu, Wen-Wang; Wang, Li-Zhi
2016-01-15
The analytic potential energy functions (APEFs) of the X(1)Σ(+), 2(1)Σ(+), a(3)Σ(+), and 2(3)Σ(+) states of the LiRb molecule are obtained using Morse long-range potential energy function with damping function and nonlinear least-squares method. These calculations were based on the potential energy curves (PECs) calculated using the multi-reference configuration interaction (MRCI) method. The reliability of the APEFs is confirmed using the curves of their first and second derivatives. By using the obtained APEFs, the rotational and vibrational energy levels of the states are determined by solving the Schrödinger equation of nuclear movement. The spectroscopic parameters, which are deduced using Dunham expansion, and the obtained rotational and vibrational levels are compared with the reported theoretical and experimental values. The correlation effect of the electrons of the inner shell remarkably improves the results compared with the experimental spectroscopic parameters. For the first time, the APEFs for the dipole moments and transition dipole moments of the states have been determined based on the curves obtained from the MRCI calculations. Copyright © 2015 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
You, Yang; Yang, Chuan-Lu; Wang, Mei-Shan; Ma, Xiao-Guang; Liu, Wen-Wang; Wang, Li-Zhi
2016-01-01
The analytic potential energy functions (APEFs) of the X1Σ+, 21Σ+, a3Σ+, and 23Σ+ states of the LiRb molecule are obtained using Morse long-range potential energy function with damping function and nonlinear least-squares method. These calculations were based on the potential energy curves (PECs) calculated using the multi-reference configuration interaction (MRCI) method. The reliability of the APEFs is confirmed using the curves of their first and second derivatives. By using the obtained APEFs, the rotational and vibrational energy levels of the states are determined by solving the Schrödinger equation of nuclear movement. The spectroscopic parameters, which are deduced using Dunham expansion, and the obtained rotational and vibrational levels are compared with the reported theoretical and experimental values. The correlation effect of the electrons of the inner shell remarkably improves the results compared with the experimental spectroscopic parameters. For the first time, the APEFs for the dipole moments and transition dipole moments of the states have been determined based on the curves obtained from the MRCI calculations.
Analytical studies on a traveling wave direct energy converter for D-{sup 3}He fusion
Syu, L.Y.; Tomita, Yukihiro; Momota, Hiromu; Miley, G.H.
1995-04-01
Analytical studies on a traveling wave direct energy converter (TWDEC) for D-{sup 3}He fueled fusion are carried out. The energy of 15 MeV carried by fusion protons is too high to handle with an electrostatic device. The TWDEC controls these high energy particles on the base of the principle of a Linac. This traveling wave method is discussed and the details of proton dynamics and excitation mechanism of electric power are clarified. The TWEDC consists of a modulator and decelerator. The applied traveling wave potential to the modulator modulates the velocity of fusion proton beams. This modulation makes a form of bunched protons at a down stream of the modulator. The decelerator has a set of meshed grids, each of which is connected to a transmission circuit. The phase velocity of excited wave on the transmission circuit is controlled the same way as that of decelerated protons. The kinetic energy 15 MeV of proton beams changes into an oscillating electromagnetic energy on the transmission circuit. This highly efficient direct energy converter of fusion protons brings a fusion reactor with a high plant efficiency. 4 refs., 4 figs.
McCahill, Peter W; Noste, Erin E; Rossman, A J; Callaway, David W
2014-12-01
Disasters create major strain on energy infrastructure in affected communities. Advances in microgrid technology offer the potential to improve "off-grid" mobile disaster medical response capabilities beyond traditional diesel generation. The Carolinas Medical Center's mobile emergency medical unit (MED-1) Green Project (M1G) is a multi-phase project designed to demonstrate the benefits of integrating distributive generation (DG), high-efficiency batteries, and "smart" energy utilization in support of major out-of-hospital medical response operations. Carolinas MED-1 is a mobile medical facility composed of a fleet of vehicles and trailers that provides comprehensive medical care capacities to support disaster response and special-event operations. The M1G project partnered with local energy companies to deploy energy analytics and an energy microgrid in support of mobile clinical operations for the 2012 Democratic National Convention (DNC) in Charlotte, North Carolina (USA). Energy use data recorded throughout the DNC were analyzed to create energy utilization models that integrate advanced battery technology, solar photovoltaic (PV), and energy conservation measures (ECM) to improve future disaster response operations. The generators that supply power for MED-1 have a minimum loading ratio (MLR) of 30 kVA. This means that loads below 30 kW lead to diesel fuel consumption at the same rate as a 30 kW load. Data gathered from the two DNC training and support deployments showed the maximum load of MED-1 to be around 20 kW. This discrepancy in MLR versus actual load leads to significant energy waste. The lack of an energy storage system reduces generator efficiency and limits integration of alternative energy generation strategies. A storage system would also allow for alternative generation sources, such as PV, to be incorporated. Modeling with a 450 kWh battery bank and 13.5 kW PV array showed a 2-fold increase in potential deployment times using the same amount of
Soares Dos Santos, Marco P; Ferreira, Jorge A F; Simões, José A O; Pascoal, Ricardo; Torrão, João; Xue, Xiaozheng; Furlani, Edward P
2016-01-04
Magnetic levitation has been used to implement low-cost and maintenance-free electromagnetic energy harvesting. The ability of levitation-based harvesting systems to operate autonomously for long periods of time makes them well-suited for self-powering a broad range of technologies. In this paper, a combined theoretical and experimental study is presented of a harvester configuration that utilizes the motion of a levitated hard-magnetic element to generate electrical power. A semi-analytical, non-linear model is introduced that enables accurate and efficient analysis of energy transduction. The model predicts the transient and steady-state response of the harvester a function of its motion (amplitude and frequency) and load impedance. Very good agreement is obtained between simulation and experiment with energy errors lower than 14.15% (mean absolute percentage error of 6.02%) and cross-correlations higher than 86%. The model provides unique insight into fundamental mechanisms of energy transduction and enables the geometric optimization of harvesters prior to fabrication and the rational design of intelligent energy harvesters.
Soares dos Santos, Marco P.; Ferreira, Jorge A. F.; Simões, José A. O.; Pascoal, Ricardo; Torrão, João; Xue, Xiaozheng; Furlani, Edward P.
2016-01-01
Magnetic levitation has been used to implement low-cost and maintenance-free electromagnetic energy harvesting. The ability of levitation-based harvesting systems to operate autonomously for long periods of time makes them well-suited for self-powering a broad range of technologies. In this paper, a combined theoretical and experimental study is presented of a harvester configuration that utilizes the motion of a levitated hard-magnetic element to generate electrical power. A semi-analytical, non-linear model is introduced that enables accurate and efficient analysis of energy transduction. The model predicts the transient and steady-state response of the harvester a function of its motion (amplitude and frequency) and load impedance. Very good agreement is obtained between simulation and experiment with energy errors lower than 14.15% (mean absolute percentage error of 6.02%) and cross-correlations higher than 86%. The model provides unique insight into fundamental mechanisms of energy transduction and enables the geometric optimization of harvesters prior to fabrication and the rational design of intelligent energy harvesters. PMID:26725842
NASA Astrophysics Data System (ADS)
Soares Dos Santos, Marco P.; Ferreira, Jorge A. F.; Simões, José A. O.; Pascoal, Ricardo; Torrão, João; Xue, Xiaozheng; Furlani, Edward P.
2016-01-01
Magnetic levitation has been used to implement low-cost and maintenance-free electromagnetic energy harvesting. The ability of levitation-based harvesting systems to operate autonomously for long periods of time makes them well-suited for self-powering a broad range of technologies. In this paper, a combined theoretical and experimental study is presented of a harvester configuration that utilizes the motion of a levitated hard-magnetic element to generate electrical power. A semi-analytical, non-linear model is introduced that enables accurate and efficient analysis of energy transduction. The model predicts the transient and steady-state response of the harvester a function of its motion (amplitude and frequency) and load impedance. Very good agreement is obtained between simulation and experiment with energy errors lower than 14.15% (mean absolute percentage error of 6.02%) and cross-correlations higher than 86%. The model provides unique insight into fundamental mechanisms of energy transduction and enables the geometric optimization of harvesters prior to fabrication and the rational design of intelligent energy harvesters.
Analytic model for ultrasound energy receivers and their optimal electric loads
NASA Astrophysics Data System (ADS)
Gorostiaga, M.; Wapler, M. C.; Wallrabe, U.
2017-08-01
In this paper, we present an analytic model for thickness resonating plate ultrasound energy receivers, which we have derived from the piezoelectric and the wave equations and, in which we have included dielectric, viscosity and acoustic attenuation losses. Afterwards, we explore the optimal electric load predictions by the zero reflection and power maximization approaches present in the literature with different acoustic boundary conditions, and discuss their limitations. To validate our model, we compared our expressions with the KLM model solved numerically with very good agreement. Finally, we discuss the differences between the zero reflection and power maximization optimal electric loads, which start to differ as losses in the receiver increase.
Energy Levels of 'Hydrogen Atom' in Discrete Time Dynamics
Khrennikov, Andrei; Volovich, Yaroslav
2006-01-04
We analyze dynamical consequences of a conjecture that there exists a fundamental (indivisible) quant of time. In particular we study the problem of discrete energy levels of hydrogen atom. We are able to reconstruct potential which in discrete time formalism leads to energy levels of unperturbed hydrogen atom. We also consider linear energy levels of quantum harmonic oscillator and show how they are produced in the discrete time formalism. More generally, we show that in discrete time formalism finite motion in central potential leads to discrete energy spectrum, the property which is common for quantum mechanical theory. Thus deterministic (but discrete time{exclamation_point}) dynamics is compatible with discrete energy levels.
Hardee County Energy Activities - Middle School Level.
ERIC Educational Resources Information Center
Allen, Rodney F., Ed.
Described are over 70 activities designed to help students develop writing skills by examining energy issues. Intended for middle school students, the lessons were developed by Hardee County, Florida teachers. Learning strategies employed include class discussions, analogies, word puzzles, letter writing, sentence completions, vocabulary building…
NASA Astrophysics Data System (ADS)
Hosen, Md. Alal; Chowdhury, M. S. H.; Ali, Mohammad Yeakub; Ismail, Ahmad Faris
In the present paper, a novel analytical approximation technique has been proposed based on the energy balance method (EBM) to obtain approximate periodic solutions for the focus generalized highly nonlinear oscillators. The expressions of the natural frequency-amplitude relationship are obtained using a novel analytical way. The accuracy of the proposed method is investigated on three benchmark oscillatory problems, namely, the simple relativistic oscillator, the stretched elastic wire oscillator (with a mass attached to its midpoint) and the Duffing-relativistic oscillator. For an initial oscillation amplitude A0 = 100, the maximal relative errors of natural frequency found in three oscillators are 2.1637%, 0.0001% and 1.201%, respectively, which are much lower than the errors found using the existing methods. It is highly remarkable that an excellent accuracy of the approximate natural frequency has been found which is valid for the whole range of large values of oscillation amplitude as compared with the exact ones. Very simple solution procedure and high accuracy that is found in three benchmark problems reveal the novelty, reliability and wider applicability of the proposed analytical approximation technique.
NASA Astrophysics Data System (ADS)
Mashayekhi, Mohammad Jalali; Behdinan, Kamran
2017-10-01
The increasing demand to minimize undesired vibration and noise levels in several high-tech industries has generated a renewed interest in vibration transfer path analysis. Analyzing vibration transfer paths within a system is of crucial importance in designing an effective vibration isolation strategy. Most of the existing vibration transfer path analysis techniques are empirical which are suitable for diagnosis and troubleshooting purpose. The lack of an analytical transfer path analysis to be used in the design stage is the main motivation behind this research. In this paper an analytical transfer path analysis based on the four-pole theory is proposed for multi-energy-domain systems. Bond graph modeling technique which is an effective approach to model multi-energy-domain systems is used to develop the system model. In this paper an electro-mechanical system is used as a benchmark example to elucidate the effectiveness of the proposed technique. An algorithm to obtain the equivalent four-pole representation of a dynamical systems based on the corresponding bond graph model is also presented in this paper.
Analytic study of the effect of dark energy-dark matter interaction on the growth of structures
NASA Astrophysics Data System (ADS)
Marcondes, Rafael J. F.; Landim, Ricardo C. G.; Costa, André A.; Wang, Bin; Abdalla, Elcio
2016-12-01
Large-scale structure has been shown as a promising cosmic probe for distinguishing and constraining dark energy models. Using the growth index parametrization, we obtain an analytic formula for the growth rate of structures in a coupled dark energy model in which the exchange of energy-momentum is proportional to the dark energy density. We find that the evolution of fσ8 can be determined analytically once we know the coupling, the dark energy equation of state, the present value of the dark energy density parameter and the current mean amplitude of dark matter fluctuations. After correcting the growth function for the correspondence with the velocity field through the continuity equation in the interacting model, we use our analytic result to compare the model's predictions with large-scale structure observations.
Zhang, Xindi; Warren, Jim; Corter, Arden; Goodyear-Smith, Felicity
2016-01-01
This paper describes development of a prototype data analytics portal for analysis of accumulated screening results from eCHAT (electronic Case-finding and Help Assessment Tool). eCHAT allows individuals to conduct a self-administered lifestyle and mental health screening assessment, with usage to date chiefly in the context of primary care waiting rooms. The intention is for wide roll-out to primary care clinics, including secondary school based clinics, resulting in the accumulation of population-level data. Data from a field trial of eCHAT with sexual health questions tailored to youth were used to support design of a data analytics portal for population-level data. The design process included user personas and scenarios, screen prototyping and a simulator for generating large-scale data sets. The prototype demonstrates the promise of wide-scale self-administered screening data to support a range of users including practice managers, clinical directors and health policy analysts.
Boothroyd, A.I. ); Dove, J.E.; Keogh, W.J. ); Martin, P.G. ); Peterson, M.R. )
1991-09-15
The interaction potential energy surface (PES) of H{sub 4} is of great importance for quantum chemistry, as a test case for molecule--molecule interactions. It is also required for a detailed understanding of certain astrophysical processes, namely, collisional excitation and dissociation of H{sub 2} in molecular clouds, at densities too low to be accessible experimentally. Accurate {ital ab} {ital initio} energies were computed for 6046 conformations of H{sub 4}, using a multiple reference (single and) double excitation configuration interaction (MRD-CI) program. Both systematic and random'' errors were estimated to have an rms size of 0.6 mhartree, for a total rms error of about 0.9 mhartree (or 0.55 kcal/mol) in the final {ital ab} {ital initio} energy values. It proved possible to include in a self-consistent way {ital ab} {ital initio} energies calculated by Schwenke, bringing the number of H{sub 4} conformations to 6101. {ital Ab} {ital initio} energies were also computed for 404 conformations of H{sub 3}; adding {ital ab} {ital initio} energies calculated by other authors yielded a total of 772 conformations of H{sub 3}. (The H{sub 3} results, and an improved analytic PES for H{sub 3}, are reported elsewhere.) {ital Ab} {ital initio} energies are tabulated in this paper only for a sample of H{sub 4} conformations; a full list of all 6101 conformations of H{sub 4} (and 772 conformations of H{sub 3} ) is available from Physics Auxiliary Publication Service (PAPS), or from the authors.
Sound energy decay in coupled spaces using a parametric analytical solution of a diffusion equation.
Luizard, Paul; Polack, Jean-Dominique; Katz, Brian F G
2014-05-01
Sound field behavior in performance spaces is a complex phenomenon. Issues regarding coupled spaces present additional concerns due to sound energy exchanges. Coupled volume concert halls have been of increasing interest in recent decades because this architectural principle offers the possibility to modify the hall's acoustical environment in a passive way by modifying the coupling area. Under specific conditions, the use of coupled reverberation chambers can provide non-exponential sound energy decay in the main room, resulting in both high clarity and long reverberation which are antagonistic parameters in a single volume room. Previous studies have proposed various sound energy decay models based on statistical acoustics and diffusion theory. Statistical acoustics assumes a perfectly uniform sound field within a given room whereas measurements show an attenuation of energy with increasing source-receiver distance. While previously proposed models based on diffusion theory use numerical solvers, the present study proposes a heuristic model of sound energy behavior based on an analytical solution of the commonly used diffusion equation and physically justified approximations. This model is validated by means of comparisons to scale model measurements and numerical geometrical acoustics simulations, both applied to the same simple concert hall geometry.
Experimental and Analytical Evaluation of a Composite Honeycomb Deployable Energy Absorber
NASA Technical Reports Server (NTRS)
Jackson, Karen E.; Kellas, Sotiris; Horta, Lucas G.; Annett, Martin S.; Polanco, Michael A.; Littell, Justin D.; Fasanella, Edwin L.
2011-01-01
In 2006, the NASA Subsonic Rotary Wing Aeronautics Program sponsored the experimental and analytical evaluation of an externally deployable composite honeycomb structure that is designed to attenuate impact energy during helicopter crashes. The concept, which is designated the Deployable Energy Absorber (DEA), utilizes an expandable Kevlar honeycomb structure to dissipate kinetic energy through crushing. The DEA incorporates a unique flexible hinge design that allows the honeycomb to be packaged and stowed flat until needed for deployment. A variety of deployment options such as linear, radial, and/or hybrid methods can be used. Experimental evaluation of the DEA utilized a building block approach that included material characterization testing of its constituent, Kevlar -129 fabric/epoxy, and flexural testing of single hexagonal cells. In addition, the energy attenuation capabilities of the DEA were demonstrated through multi-cell component dynamic crush tests, and vertical drop tests of a composite fuselage section, retrofitted with DEA blocks, onto concrete, water, and soft soil. During each stage of the DEA evaluation process, finite element models of the test articles were developed and simulations were performed using the explicit, nonlinear transient dynamic finite element code, LS-DYNA. This report documents the results of the experimental evaluation that was conducted to assess the energy absorption capabilities of the DEA.
Precise analytical description of the Earth matter effect on oscillations of low energy neutrinos
Ioannisian, A.N.; Kazarian, N.A.; Smirnov, A.Yu.; Wyler, D.
2005-02-01
We present a formalism for the matter effects in the Earth on low energy neutrino fluxes which is both accurate and has all the advantages of a full analytic treatment. The oscillation probabilities are calculated up to the second order term in {epsilon}(x){identical_to}2V(x)E/{delta}m{sup 2}, where V(x) is the neutrino potential at position x. We show the absence of large undamped phases which makes the expansion in {epsilon} well behaved. An improved expansion is presented in terms of the variation of V(x) around a suitable mean value which allows one to treat energies up to those relevant for supernova neutrinos. We discuss also the case of three-neutrino mixing.
A new analytical potential energy surface for the singlet state of He2H+
NASA Astrophysics Data System (ADS)
Liang, Jing-Juan; Yang, Chuan-Lu; Wang, Li-Zhi; Zhang, Qing-Gang
2012-03-01
The analytic potential energy surface (APES) for the exchange reaction of HeH+ (X1Σ+) + He at the lowest singlet state 11A/ has been built. The APES is expressed as Aguado-Paniagua function based on the many-body expansion. Using the adaptive non-linear least-squares algorithm, the APES is fitted from 15 682 ab initio energy points calculated with the multireference configuration interaction calculation with a large d-aug-cc-pV5Z basis set. To testify the new APES, we calculate the integral cross sections for He + H+He (v = 0, 1, 2, j = 0) → HeH+ + He by means of quasi-classical trajectory and compare them with the previous result in literature.
NASA Astrophysics Data System (ADS)
Watson, P. J.
2016-12-01
The detection of acceleration in mean sea-level around the data rich margins of the USA has been a keen endeavour of sea-level researchers post the seminal work of Bruce Douglas in 1992. Over the past decade, such investigations have taken on greater prominence given mean sea-level remains a key proxy by which to measure a changing climate system. The physics-based climate projection models are forecasting that the current global average rate of mean sea-level rise (≈ 3mm/year) might climb to rates in the range of 10-20 mm/year by 2100. Most research in this area has centred on reconciling current rates of rise with the significant accelerations required to meet the forecast projections of climate models. Various studies conducted over the past decade have provided inconsistent results which in part are due to both the small kinematic properties of the mean sea level signal evident in historical time series data and the limited analytical techniques applied to date to measure these phenomena. The analysis presented is based on a recently developed analytical package titled `msltrend', designed to augment climate change research by significantly enhancing estimates of trend, real-time velocity and acceleration in the relative mean sea-level signal derived from long annual average ocean water level time series. Key findings are that at the 95% confidence level, there is no consistent or substantial evidence (yet) that recent rates of rise are higher or abnormal in the context of the network of lengthy historical records available for the USA, nor is there any evidence that geocentric rates of rise are above the global average. The analysis also points to clearer spatial and temporal patterns in measured mean sea level around mainland USA than previously available. It is likely a further 20 years of data will distinguish whether recent increases east of Galveston and along the east coast are evidence of the onset of climate change induced acceleration.
Ground Levels and Ionization Energies for the Neutral Atoms
National Institute of Standards and Technology Data Gateway
SRD 111 Ground Levels and Ionization Energies for the Neutral Atoms (Web, free access) Data for ground state electron configurations and ionization energies for the neutral atoms (Z = 1-104) including references.
NASA Astrophysics Data System (ADS)
Gharabaghi, Masumeh; Shahbazian, Shant
2017-04-01
The quantum theory of atoms in molecules (QTAIM) is based on the clamped nucleus paradigm and solely working with the electronic wavefunctions, so does not include nuclear vibrations in the AIM analysis. On the other hand, the recently extended version of the QTAIM, called the multi-component QTAIM (MC-QTAIM), incorporates both electrons and quantum nuclei, i.e., those nuclei treated as quantum waves instead of clamped point charges, into the AIM analysis using non-adiabatic wavefunctions. Thus, the MC-QTAIM is the natural framework to incorporate the role of nuclear vibrations into the AIM analysis. In this study, within the context of the MC-QTAIM, the formalism of including nuclear vibrational energy in the atomic basin energy is developed in detail and its contribution is derived analytically using the recently proposed non-adiabatic Hartree product nuclear wavefunction. It is demonstrated that within the context of this wavefunction, the quantum nuclei may be conceived pseudo-adiabatically as quantum oscillators and both isotropic harmonic and anisotropic anharmonic oscillator models are used to compute the zero-point nuclear vibrational energy contribution to the basin energies explicitly. Inspired by the results gained within the context of the MC-QTAIM analysis, a heuristic approach is proposed within the context of the QTAIM to include nuclear vibrational energy in the basin energy from the vibrational wavefunction derived adiabatically. The explicit calculation of the basin contribution of the zero-point vibrational energy using the uncoupled harmonic oscillator model leads to results consistent with those derived from the MC-QTAIM.
Gharabaghi, Masumeh; Shahbazian, Shant
2017-04-21
The quantum theory of atoms in molecules (QTAIM) is based on the clamped nucleus paradigm and solely working with the electronic wavefunctions, so does not include nuclear vibrations in the AIM analysis. On the other hand, the recently extended version of the QTAIM, called the multi-component QTAIM (MC-QTAIM), incorporates both electrons and quantum nuclei, i.e., those nuclei treated as quantum waves instead of clamped point charges, into the AIM analysis using non-adiabatic wavefunctions. Thus, the MC-QTAIM is the natural framework to incorporate the role of nuclear vibrations into the AIM analysis. In this study, within the context of the MC-QTAIM, the formalism of including nuclear vibrational energy in the atomic basin energy is developed in detail and its contribution is derived analytically using the recently proposed non-adiabatic Hartree product nuclear wavefunction. It is demonstrated that within the context of this wavefunction, the quantum nuclei may be conceived pseudo-adiabatically as quantum oscillators and both isotropic harmonic and anisotropic anharmonic oscillator models are used to compute the zero-point nuclear vibrational energy contribution to the basin energies explicitly. Inspired by the results gained within the context of the MC-QTAIM analysis, a heuristic approach is proposed within the context of the QTAIM to include nuclear vibrational energy in the basin energy from the vibrational wavefunction derived adiabatically. The explicit calculation of the basin contribution of the zero-point vibrational energy using the uncoupled harmonic oscillator model leads to results consistent with those derived from the MC-QTAIM.
An analytical ab initio potential surface and the calculated tunneling energies for the HCl dimer
NASA Astrophysics Data System (ADS)
Bunker, P. R.; Epa, V. C.; Jensen, Per; Karpfen, Alfred
1991-03-01
The six-dimensional potential energy surface of the HCl dimer has been calculated ab initio at 1654 nuclear geometries [A. Karpfen, P. R. Bunker and P. Jensen, Chem. Phys., in press]. In the present paper we have fitted an analytical function to these points; the analytical function is similar to that used previously by us for the potential surface of the HF dimer. The fitted function has 38 adjustable parameters and the standard deviation of the weighted fit is 19.0 cm -1. We have determined the minimum energy path for the trans-bending tunneling motion on this surface, and have calculated the tunneling and K-rotation energies and wavefunctions. Around equilibrium the path is qualitatively similar to that for the HF dimer in that there are two equivalent hydrogen-bonded structures of Cs symmetry (which are approximately L-shaped with a "bound" and a "free" H-atom) that can tunnel through a C2 h saddle point (the "closed" C2 h saddle point). However, away from equilibrium the path is qualitatively different from that found for the HF dimer since the HCl dimer never becomes linear along the path; in fact it passes through a second C2 h saddle point (the "open" C2 h saddle point). As a result the A-rotational constant only varies slightly along the path, and this explains the experimental observation that the tunneling splitting varies little with K-type rotation for the HCl dimer, in contrast to the situation for the HF dimer. Quantitatively it is clear that errors in the ab initio calculation, errors in the fitting of an analytic function to the points, the correction to the path that is caused by the zero point motion in the other vibrations, and the coupling between the four low-frequency modes, will all be relatively more significant than they were for the HF dimer because the full six-dimensional potential is much flatter; the ab initio dissociation energy is only ˜600 cm -1, and the ab initio tunneling barrier is only ˜70 cm -1. Therefore, we modify the
A Big Data and Learning Analytics Approach to Process-Level Feedback in Cognitive Simulations.
Pecaric, Martin; Boutis, Kathy; Beckstead, Jason; Pusic, Martin
2017-02-01
Collecting and analyzing large amounts of process data for the purposes of education can be considered a big data/learning analytics (BD/LA) approach to improving learning. However, in the education of health care professionals, the application of BD/LA is limited to date. The authors discuss the potential advantages of the BD/LA approach for the process of learning via cognitive simulations. Using the lens of a cognitive model of radiograph interpretation with four phases (orientation, searching/scanning, feature detection, and decision making), they reanalyzed process data from a cognitive simulation of pediatric ankle radiography where 46 practitioners from three expertise levels classified 234 cases online. To illustrate the big data component, they highlight the data available in a digital environment (time-stamped, click-level process data). Learning analytics were illustrated using algorithmic computer-enabled approaches to process-level feedback.For each phase, the authors were able to identify examples of potentially useful BD/LA measures. For orientation, the trackable behavior of re-reviewing the clinical history was associated with increased diagnostic accuracy. For searching/scanning, evidence of skipping views was associated with an increased false-negative rate. For feature detection, heat maps overlaid on the radiograph can provide a metacognitive visualization of common novice errors. For decision making, the measured influence of sequence effects can reflect susceptibility to bias, whereas computer-generated path maps can provide insights into learners' diagnostic strategies.In conclusion, the augmented collection and dynamic analysis of learning process data within a cognitive simulation can improve feedback and prompt more precise reflection on a novice clinician's skill development.
NASA Astrophysics Data System (ADS)
Brusa, E.; Zelenika, S.; Moro, L.; Benasciutti, D.
2009-05-01
One of the main requirements in wireless sensor operation is the availability of autonomous power sources sufficiently compact to be embedded in the same housing and, when the application involves living people, wearable. A possible technological solution satisfying these needs is energy harvesting from the environment. Vibration energy scavenging is one of the most studied approaches in this frame. In this work the conversion of kinetic into electric energy via piezoelectric coupling in resonant beams is studied. Various design approaches are analyzed and relevant parameters are identified. Numerical methods are applied to stress and strain analyses as well as to evaluate the voltage and charge generated by electromechanical coupling. The aim of the work is increasing the specific power generated per unit of scavenger volume by optimizing its shape. Besides the conventional rectangular geometry proposed in literature, two trapezoidal shapes, namely the direct and the reversed trapezoidal configuration, are analyzed. They are modeled to predict their dynamic behavior and energy conversion performance. Analytical and FEM models are compared and resulting figures of merit are drawn. Results of a preliminary experimental validation are also given. A systematic validation of characteristic specimens via an experimental campaign is ongoing.
Visual Analytics for the Food-Water-Energy Nexus in the Phoenix Active Management Area
NASA Astrophysics Data System (ADS)
Maciejewski, R.; Mascaro, G.; White, D. D.; Ruddell, B. L.; Aggarwal, R.; Sarjoughian, H.
2016-12-01
The Phoenix Active Management Area (AMA) is an administrative region of 14,500 km2 identified by the Arizona Department of Water Resources with the aim of reaching and maintaining the safe yield (i.e. balance between annual amount of groundwater withdrawn and recharged) by 2025. The AMA includes the Phoenix metropolitan area, which has experienced a dramatic population growth over the last decades with a progressive conversion of agricultural land into residential land. As a result of these changes, the water and energy demand as well as the food production in the region have significantly evolved over the last 30 years. Given the arid climate, a crucial role to support this growth has been the creation of a complex water supply system based on renewable and non-renewable resources, including the energy-intensive Central Arizona Project. In this talk, we present a preliminary characterization of the evolution in time of the feedbacks between food, water, and energy in the Phoenix AMA by analyzing secondary data (available from water and energy providers, irrigation districts, and municipalities), as well as satellite imagery and primary data collected by the authors. A preliminary visual analytics framework is also discussed describing current design practices and ideas for exploring networked components and cascading impacts within the FEW Nexus. This analysis and framework represent the first steps towards the development of an integrated modeling, visualization, and decision support infrastructure for comprehensive FEW systems decision making at decision-relevant temporal and spatial scales.
Analytical Energy Gradients for Excited-State Coupled-Cluster Methods
NASA Astrophysics Data System (ADS)
Wladyslawski, Mark; Nooijen, Marcel
The equation-of-motion coupled-cluster (EOM-CC) and similarity transformed equation-of-motion coupled-cluster (STEOM-CC) methods have been firmly established as accurate and routinely applicable extensions of single-reference coupled-cluster theory to describe electronically excited states. An overview of these methods is provided, with emphasis on the many-body similarity transform concept that is the key to a rationalization of their accuracy. The main topic of the paper is the derivation of analytical energy gradients for such non-variational electronic structure approaches, with an ultimate focus on obtaining their detailed algebraic working equations. A general theoretical framework using Lagrange's method of undetermined multipliers is presented, and the method is applied to formulate the EOM-CC and STEOM-CC gradients in abstract operator terms, following the previous work in [P.G. Szalay, Int. J. Quantum Chem. 55 (1995) 151] and [S.R. Gwaltney, R.J. Bartlett, M. Nooijen, J. Chem. Phys. 111 (1999) 58]. Moreover, the systematics of the Lagrange multiplier approach is suitable for automation by computer, enabling the derivation of the detailed derivative equations through a standardized and direct procedure. To this end, we have developed the SMART (Symbolic Manipulation and Regrouping of Tensors) package of automated symbolic algebra routines, written in the Mathematica programming language. The SMART toolkit provides the means to expand, differentiate, and simplify equations by manipulation of the detailed algebraic tensor expressions directly. The Lagrangian multiplier formulation establishes a uniform strategy to perform the automated derivation in a standardized manner: A Lagrange multiplier functional is constructed from the explicit algebraic equations that define the energy in the electronic method; the energy functional is then made fully variational with respect to all of its parameters, and the symbolic differentiations directly yield the explicit
Analytical study of the energy rate balance equation for the magnetospheric storm-ring current
NASA Astrophysics Data System (ADS)
Clúa de Gonzalez, A. L.; Gonzalez, W. D.
1998-11-01
We present some results of the analytical integration of the energy rate balance equation, assuming that the input energy rate is proportional to the azimuthal interplanetary electric field, Ey, and can be described by simple rectangular or triangular functions, as approximations to the frequently observed shapes of Ey, especially during the passage of magnetic clouds. The input function is also parametrized by a reconnection-transfer efficiency factor
NASA Astrophysics Data System (ADS)
Ghosh, Arindam; Islam, Khairul; Bhattacharyya, Dipankar; Bandyopadhyay, Amitava
2016-10-01
We report the occurrence of electromagnetically induced transparency (EIT) in the simulated probe response signal for a four-level inverted-Y type system that is being acted upon by a weak coherent probe field, a strong coherent pump field and a coherent repump field. There are two ground energy levels, one intermediate energy level and one uppermost energy level. The weak probe field couples the lowest ground level to the intermediate level whereas the repump field connects the other ground level with the intermediate level. The strong control field couples the intermediate level with the uppermost energy level, thereby forming an inverted-Y type system. The density matrix based theoretical model has been developed and solved analytically for this four-level system and the probe response signal has been simulated at different values of the control and repump Rabi frequencies, control and repump frequency detunings and under both Doppler-free and Doppler-broadened conditions using the parameters of 87Rb D2 transition. Extremely low line width (few tens of kHz) for the EIT signal has been noticed under thermal averaging for copropagating probe, control and repump field configuration. The EIT signal is found to be immune to the variation in the control Rabi frequency.
Secondary Data Analytics of Aquaporin Expression Levels in Glioblastoma Stem-Like Cells.
Isokpehi, Raphael D; Wollenberg Valero, Katharina C; Graham, Barbara E; Pacurari, Maricica; Sims, Jennifer N; Udensi, Udensi K; Ndebele, Kenneth
2015-01-01
Glioblastoma is the most common brain tumor in adults in which recurrence has been attributed to the presence of cancer stem cells in a hypoxic microenvironment. On the basis of tumor formation in vivo and growth type in vitro, two published microarray gene expression profiling studies grouped nine glioblastoma stem-like (GS) cell lines into one of two groups: full (GSf) or restricted (GSr) stem-like phenotypes. Aquaporin-1 (AQP1) and aquaporin-4 (AQP4) are water transport proteins that are highly expressed in primary glial-derived tumors. However, the expression levels of AQP1 and AQP4 have not been previously described in a panel of 92 glioma samples. Therefore, we designed secondary data analytics methods to determine the expression levels of AQP1 and AQP4 in GS cell lines and glioblastoma neurospheres. Our investigation also included a total of 2,566 expression levels from 28 Affymetrix microarray probe sets encoding 13 human aquaporins (AQP0-AQP12); CXCR4 (the receptor for stromal cell derived factor-1 [SDF-1], a potential glioma stem cell therapeutic target]); and PROM1 (gene encoding CD133, the widely used glioma stem cell marker). Interactive visual representation designs for integrating phenotypic features and expression levels revealed that inverse expression levels of AQP1 and AQP4 correlate with distinct phenotypes in a set of cell lines grouped into full and restricted stem-like phenotypes. Discriminant function analysis further revealed that AQP1 and AQP4 expression are better predictors for tumor formation and growth types in glioblastoma stem-like cells than are CXCR4 and PROM1. Future investigations are needed to characterize the molecular mechanisms for inverse expression levels of AQP1 and AQP4 in the glioblastoma stem-like neurospheres.
Secondary Data Analytics of Aquaporin Expression Levels in Glioblastoma Stem-Like Cells
Isokpehi, Raphael D; Wollenberg Valero, Katharina C; Graham, Barbara E; Pacurari, Maricica; Sims, Jennifer N; Udensi, Udensi K; Ndebele, Kenneth
2015-01-01
Glioblastoma is the most common brain tumor in adults in which recurrence has been attributed to the presence of cancer stem cells in a hypoxic microenvironment. On the basis of tumor formation in vivo and growth type in vitro, two published microarray gene expression profiling studies grouped nine glioblastoma stem-like (GS) cell lines into one of two groups: full (GSf) or restricted (GSr) stem-like phenotypes. Aquaporin-1 (AQP1) and aquaporin-4 (AQP4) are water transport proteins that are highly expressed in primary glial-derived tumors. However, the expression levels of AQP1 and AQP4 have not been previously described in a panel of 92 glioma samples. Therefore, we designed secondary data analytics methods to determine the expression levels of AQP1 and AQP4 in GS cell lines and glioblastoma neurospheres. Our investigation also included a total of 2,566 expression levels from 28 Affymetrix microarray probe sets encoding 13 human aquaporins (AQP0–AQP12); CXCR4 (the receptor for stromal cell derived factor-1 [SDF-1], a potential glioma stem cell therapeutic target]); and PROM1 (gene encoding CD133, the widely used glioma stem cell marker). Interactive visual representation designs for integrating phenotypic features and expression levels revealed that inverse expression levels of AQP1 and AQP4 correlate with distinct phenotypes in a set of cell lines grouped into full and restricted stem-like phenotypes. Discriminant function analysis further revealed that AQP1 and AQP4 expression are better predictors for tumor formation and growth types in glioblastoma stem-like cells than are CXCR4 and PROM1. Future investigations are needed to characterize the molecular mechanisms for inverse expression levels of AQP1 and AQP4 in the glioblastoma stem-like neurospheres. PMID:26279619
ERIC Educational Resources Information Center
Lamb, Theodore A.; Chin, Keric B. O.
This paper proposes a conceptual framework based on different levels of analysis using the metaphor of the layers of an onion to help organize and structure thinking on research issues concerning training. It discusses the core of the "analytic onion," the biological level, and seven levels of analysis that surround that core: the individual, the…
ORNL takes energy-efficient housing to a new level
2008-12-19
Oak Ridge National Laboratory, TVA and the Department of Energy are taking energy-saving research into a West Knox County neighborhood. In the Campbell Creek subdivision, ORNL researchers have helped builders to construct three homes with three different levels of energy-saving features.
ORNL takes energy-efficient housing to a new level
None
2016-07-12
Oak Ridge National Laboratory, TVA and the Department of Energy are taking energy-saving research into a West Knox County neighborhood. In the Campbell Creek subdivision, ORNL researchers have helped builders to construct three homes with three different levels of energy-saving features.
NASA Astrophysics Data System (ADS)
Davis, Christopher
The competitive market for retail energy providers in Texas has been in existence for 10 years. When the market opened in 2002, 5 energy providers existed, offering, on average, 20 residential product plans in total. As of January 2012, there are now 115 energy providers in Texas offering over 300 residential product plans for customers. With the increase in providers and product plans, customers can be bombarded with information and suffer from the "too much choice" effect. The goal of this praxis is to aid customers in the decision making process of identifying an energy provider and product plan. Using the Analytic Hierarchy Process (AHP), a hierarchical decomposition decision making tool, and the Incomplete Analytic Hierarchy Process (IAHP), a modified version of AHP, customers can prioritize criteria such as price, rate type, customer service, and green energy products to identify the provider and plan that best meets their needs. To gather customer data, a survey tool has been developed for customers to complete the pairwise comparison process. Results are compared for the Incomplete AHP and AHP method to determine if the Incomplete AHP method is just as accurate, but more efficient, than the traditional AHP method.
Taste clusters of music and drugs: evidence from three analytic levels.
Vuolo, Mike; Uggen, Christopher; Lageson, Sarah
2014-09-01
This article examines taste clusters of musical preferences and substance use among adolescents and young adults. Three analytic levels are considered: fixed effects analyses of aggregate listening patterns and substance use in US radio markets, logistic regressions of individual genre preferences and drug use from a nationally representative survey of US youth, and arrest and seizure data from a large American concert venue. A consistent picture emerges from all three levels: rock music is positively associated with substance use, with some substance-specific variability across rock sub-genres. Hip hop music is also associated with higher use, while pop and religious music are associated with lower use. These results are robust to fixed effects models that account for changes over time in radio markets, a comprehensive battery of controls in the individual-level survey, and concert data establishing the co-occurrence of substance use and music listening in the same place and time. The results affirm a rich tradition of qualitative and experimental studies, demonstrating how symbolic boundaries are simultaneously drawn around music and drugs. © London School of Economics and Political Science 2014.
NASA Technical Reports Server (NTRS)
Wilson, L. W.
1974-01-01
The present work investigates analytically the effect of an intermediate or intense magnetic field, such as probably exist in white dwarfs and near pulsars, on the binding energy of the hydrogen ground state. A wave-function 'prescription' is given for an analytic variational calculation of the binding energy. The calculation still gives a smooth transition between intermediate and intense fields. An explicit calculation of the ground-state binding energy as B goes to infinity is provided for the Yafet et al. (1956) trial function.
NASA Technical Reports Server (NTRS)
Wilson, L. W.
1974-01-01
The present work investigates analytically the effect of an intermediate or intense magnetic field, such as probably exist in white dwarfs and near pulsars, on the binding energy of the hydrogen ground state. A wave-function 'prescription' is given for an analytic variational calculation of the binding energy. The calculation still gives a smooth transition between intermediate and intense fields. An explicit calculation of the ground-state binding energy as B goes to infinity is provided for the Yafet et al. (1956) trial function.
Full-dimensional (15-dimensional) ab initio analytical potential energy surface for the H7+ cluster
NASA Astrophysics Data System (ADS)
Barragán, Patricia; Prosmiti, Rita; Wang, Yimin; Bowman, Joel M.
2012-06-01
Full-dimensional ab initio potential energy surface is constructed for the H_7^+ cluster. The surface is a fit to roughly 160 000 interaction energies obtained with second-order MöllerPlesset perturbation theory and the cc-pVQZ basis set, using the invariant polynomial method [B. J. Braams and J. M. Bowman, Int. Rev. Phys. Chem. 28, 577 (2009), 10.1080/01442350903234923]. We employ permutationally invariant basis functions in Morse-type variables for all the internuclear distances to incorporate permutational symmetry with respect to interchange of H atoms into the representation of the surface. We describe how different configurations are selected in order to create the database of the interaction energies for the linear least squares fitting procedure. The root-mean-square error of the fit is 170 cm-1 for the entire data set. The surface dissociates correctly to the H_5^+ + H2 fragments. A detailed analysis of its topology, as well as comparison with additional ab initio calculations, including harmonic frequencies, verify the quality and accuracy of the parameterized potential. This is the first attempt to present an analytical representation of the 15-dimensional surface of the H_7^+ cluster for carrying out dynamics studies.
Full-dimensional analytical ab initio potential energy surface of the ground state of HOI.
de Oliveira-Filho, Antonio G S; Aoto, Yuri A; Ornellas, Fernando R
2011-07-28
Extensive ab initio calculations using a complete active space second-order perturbation theory wavefunction, including scalar and spin-orbit relativistic effects with a quadruple-zeta quality basis set were used to construct an analytical potential energy surface (PES) of the ground state of the [H, O, I] system. A total of 5344 points were fit to a three-dimensional function of the internuclear distances, with a global root-mean-square error of 1.26 kcal mol(-1). The resulting PES describes accurately the main features of this system: the HOI and HIO isomers, the transition state between them, and all dissociation asymptotes. After a small adjustment, using a scaling factor on the internal coordinates of HOI, the frequencies calculated in this work agree with the experimental data available within 10 cm(-1).
Full-dimensional analytical ab initio potential energy surface of the ground state of HOI
NASA Astrophysics Data System (ADS)
de Oliveira-Filho, Antonio G. S.; Aoto, Yuri A.; Ornellas, Fernando R.
2011-07-01
Extensive ab initio calculations using a complete active space second-order perturbation theory wavefunction, including scalar and spin-orbit relativistic effects with a quadruple-zeta quality basis set were used to construct an analytical potential energy surface (PES) of the ground state of the [H, O, I] system. A total of 5344 points were fit to a three-dimensional function of the internuclear distances, with a global root-mean-square error of 1.26 kcal mol-1. The resulting PES describes accurately the main features of this system: the HOI and HIO isomers, the transition state between them, and all dissociation asymptotes. After a small adjustment, using a scaling factor on the internal coordinates of HOI, the frequencies calculated in this work agree with the experimental data available within 10 cm-1.
The Analytical Parametrization of Fusion Barrier by Using the Skyrme Energy-Density Function Model
NASA Astrophysics Data System (ADS)
Zanganeh, V.; Mirzaei, M.; N., Wang
2015-08-01
Using the skyrme energy density formalism, a pocket formula is introduced for barrier heights and positions of 95 fusion reactions (48 ≤ ZP ZT ≤ 1520) with respect to the charge and mass numbers of the interacting nuclei. It is shown that the parameterized values of RB and VB are able to reproduce the corresponding experimental data with good accuracy. Moreover, the absolute errors of our formulas are less than those obtained using the analytical parametrization forms of the fusion barrier based on the proximity versions. The ability of the parameterized forms of the barrier heights and its positions to reproduce the experimental data of the fusion cross section have been analyzed using the Wong model.
Bending energy of a vesicle to which a small spherical particle adhere: An analytical study
NASA Astrophysics Data System (ADS)
Cao, Si-Qin; Wei, Guang-Hong; Chen, Jeff Z. Y.
2015-09-01
On the basis of Helfrich’s bending energy model, we show that the adsorption process of a small spherical particle to a closed vesicle can be analytically studied by retaining the leading terms in an expansion of the shape equation. Our general derivation predicts the optimal binding sites on a vesicle, where the local membrane shape of the binding site could be non-axisymmetric before the continuous adhesion transition takes place. Our derivation avoids directly solving the shape equation and depends on an integration of the contact-line condition. The results are verified by several examples of independent numerical solutions. Project supported by the National Natural Science Foundation of China (Grant Nos. 11074047 and 11274075), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. RFDP-20100071110006), and the Natural Science and Science Engineering Council of Canada.
Energy-optimal path planning by stochastic dynamically orthogonal level-set optimization
NASA Astrophysics Data System (ADS)
Subramani, Deepak N.; Lermusiaux, Pierre F. J.
2016-04-01
A stochastic optimization methodology is formulated for computing energy-optimal paths from among time-optimal paths of autonomous vehicles navigating in a dynamic flow field. Based on partial differential equations, the methodology rigorously leverages the level-set equation that governs time-optimal reachability fronts for a given relative vehicle-speed function. To set up the energy optimization, the relative vehicle-speed and headings are considered to be stochastic and new stochastic Dynamically Orthogonal (DO) level-set equations are derived. Their solution provides the distribution of time-optimal reachability fronts and corresponding distribution of time-optimal paths. An optimization is then performed on the vehicle's energy-time joint distribution to select the energy-optimal paths for each arrival time, among all stochastic time-optimal paths for that arrival time. Numerical schemes to solve the reduced stochastic DO level-set equations are obtained, and accuracy and efficiency considerations are discussed. These reduced equations are first shown to be efficient at solving the governing stochastic level-sets, in part by comparisons with direct Monte Carlo simulations. To validate the methodology and illustrate its accuracy, comparisons with semi-analytical energy-optimal path solutions are then completed. In particular, we consider the energy-optimal crossing of a canonical steady front and set up its semi-analytical solution using a energy-time nested nonlinear double-optimization scheme. We then showcase the inner workings and nuances of the energy-optimal path planning, considering different mission scenarios. Finally, we study and discuss results of energy-optimal missions in a wind-driven barotropic quasi-geostrophic double-gyre ocean circulation.
NASA Astrophysics Data System (ADS)
Zhou, Shengxi; Hobeck, Jared D.; Cao, Junyi; Inman, Daniel J.
2017-03-01
This paper makes a complete investigation of flexible longitudinal zigzag (FLZ) energy harvesters for the purpose of enhancing energy harvesting from low-frequency and low-amplitude excitation. A general theoretical model of the FLZ energy harvesters with large joint block mass is proposed. In order to verify the accuracy of the theoretical model, both experimental results and finite element analysis via ANSYS software are presented. Results show that the theoretical model can successfully predict the dynamic response and the output power of the FLZ energy harvesters. Both theoretical and experimental results demonstrate that the proposed energy harvesters can effectively harvest vibration energy even when the direction of excitation relative to the harvester varies from 0° to 90°. Under the low excitation level of 0.18 m s‑2, the experimental maximum output power of a FLZ energy harvester with five beams was found to be 1.016 mW. Finally, the results indicate that the proposed structure is capable of effective energy conversion across a large range of excitation angles at low-frequency and low-amplitude excitations, which makes it suitable for a wide range of working conditions.
Sleep, brain energy levels, and food intake
Dworak, M.; Kim, T.; McCarley, R.W.; Basheer, R.
2013-01-01
Background The feeling of hunger and feeding, a wake–state-dependent behavior, is regulated by specific centers within the hypothalamus. While paraventricular nucleus (PVN), arcuate nucleus (ARC), and dorso- and ventromedial hypothalamus (DMH/VMH) regulate feeding, the lateral hypothalamus (LH) is associated both with feeding and wake/REM sleep regulation. In order to examine the effects of sleep and wakefulness on food intake and body weight, we also measured hypothalamic ATP concentrations, which are known to be involved in feeding behavior and sleep–wake regulation. Methods In rats, food intake and body weight was measured during a 24-h light–dark cycle and during 6 h of sleep deprivation (SD) performed by gentle handling. Tissue samples from the PVN, ARC/DMH/VMH, and LH were collected after 6 h of SD and from time-matched diurnal controls. ATP was measured by luciferin-luciferase bioluminescence assay. Results Across the 24-h light–dark period, rats consumed approximately 28.13±4.48 g of food and gained 5.22±1.65 g with a positive correlation between food intake and body weight. During SD, while food intake increased significantly +147.31±6.13%, they lost weight significantly (–93.29±13.64%) when compared to undisturbed controls. SD resulted in a significant decrease in ATP levels only in LH (–44.60±21.13%) with no change in PVN, ARC/DMH/VMH region when compared with undisturbed controls. Conclusion The results indicate a strong overall correlation between ATP concentrations in the LH and individual food intake and suggest a sleep–wake dependent neuronal control of food intake and body weight. PMID:23585726
Siragusa, Mattia; Baiocco, Giorgio; Fredericia, Pil M; Friedland, Werner; Groesser, Torsten; Ottolenghi, Andrea; Jensen, Mikael
2017-08-01
COmputation Of Local Electron Release (COOLER), a software program has been designed for dosimetry assessment at the cellular/subcellular scale, with a given distribution of administered low-energy electron-emitting radionuclides in cellular compartments, which remains a critical step in risk/benefit analysis for advancements in internal radiotherapy. The software is intended to overcome the main limitations of the medical internal radiation dose (MIRD) formalism for calculations of cellular S-values (i.e., dose to a target region in the cell per decay in a given source region), namely, the use of the continuous slowing down approximation (CSDA) and the assumption of a spherical cell geometry. To this aim, we developed an analytical approach, entrusted to a MATLAB-based program, using as input simulated data for electron spatial energy deposition directly derived from full Monte Carlo track structure calculations with PARTRAC. Results from PARTRAC calculations on electron range, stopping power and residual energy versus traveled distance curves are presented and, when useful for implementation in COOLER, analytical fit functions are given. Example configurations for cells in different culture conditions (V79 cells in suspension or adherent culture) with realistic geometrical parameters are implemented for use in the tool. Finally, cellular S-value predictions by the newly developed code are presented for different cellular geometries and activity distributions (uniform activity in the nucleus, in the entire cell or on the cell surface), validated against full Monte Carlo calculations with PARTRAC, and compared to MIRD standards, as well as results based on different track structure calculations (Geant4-DNA). The largest discrepancies between COOLER and MIRD predictions were generally found for electrons between 25 and 30 keV, where the magnitude of disagreement in S-values can vary from 50 to 100%, depending on the activity distribution. In calculations for
Levelized Cost and Levelized Avoided Cost of New Generation Resources in the Annual Energy Outlook
2016-01-01
This paper presents average values of levelized costs for generating technologies entering service in 2018, 2022, and 2040 as represented in the National Energy Modeling System (NEMS) for the Annual Energy Outlook 2016 (AEO2016) Reference case.
Levelized Cost and Levelized Avoided Cost of New Generation Resources in the Annual Energy Outlook
2017-01-01
This paper presents average values of levelized costs for generating technologies entering service in 2019, 2022, and 2040 as represented in the National Energy Modeling System (NEMS) for the Annual Energy Outlook 2017 (AEO2017) Reference case.
Salivary metal levels of orthodontic patients: a novel methodological and analytical approach.
Eliades, Theodore; Trapalis, Christos; Eliades, George; Katsavrias, Elias
2003-02-01
The purpose of this study was to qualitatively and quantitatively assess the nickel, chromium, and ferrous levels in a population of 17 orthodontic patients undergoing treatment, compared with seven untreated individuals, employing a novel methodological approach and a new analytical technique. Salivary samples obtained from patients before and after rinsing with double distilled water were processed for Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) for simultaneous estimation of the concentration of the metallic elements. No statistically significant difference was detected between control and patient groups with respect to salivary metal content, regardless of element. The range of salivary metal levels found did not exceed those of daily intake through food and air. The lack of a continuous monitoring scheme for salivary metal concentrations in real time may impose substantial obstacles to defining the release rate of metals in vivo. The results of this study emphasize the necessity of incorporating the dimension of time in assessing the release potential of orthodontic alloys.
Loveridge, A. J.; Van der Sluys, M. V.; Kalogera, V.
2011-12-10
The common-envelope (CE) phase is an important stage in the evolution of binary stellar populations. The most common way to compute the change in orbital period during a CE is to relate the binding energy of the envelope of the Roche-lobe filling giant to the change in orbital energy. Especially in population-synthesis codes, where the evolution of millions of stars must be computed and detailed evolutionary models are too expensive computationally, simple approximations are made for the envelope binding energy. In this study, we present accurate analytic prescriptions based on detailed stellar-evolution models that provide the envelope binding energy for giants with metallicities between Z = 10{sup -4} and Z = 0.03 and masses between 0.8 M{sub Sun} and 100 M{sub Sun }, as a function of the metallicity, mass, radius, and evolutionary phase of the star. Our results are also presented in the form of electronic data tables and Fortran routines that use them. We find that the accuracy of our fits is better than 15% for 90% of our model data points in all cases, and better than 10% for 90% of our data points in all cases except the asymptotic giant branches for three of the six metallicities we consider. For very massive stars (M {approx}> 50 M{sub Sun }), when stars lose more than {approx}20% of their initial mass due to stellar winds, our fits do not describe the models as accurately. Our results are more widely applicable-covering wider ranges of metallicity and mass-and are of higher accuracy than those of previous studies.
Xiao, Zhu; Liu, Hongjing; Havyarimana, Vincent; Li, Tong; Wang, Dong
2016-11-04
In this paper, we investigate the coverage performance and energy efficiency of multi-tier heterogeneous cellular networks (HetNets) which are composed of macrocells and different types of small cells, i.e., picocells and femtocells. By virtue of stochastic geometry tools, we model the multi-tier HetNets based on a Poisson point process (PPP) and analyze the Signal to Interference Ratio (SIR) via studying the cumulative interference from pico-tier and femto-tier. We then derive the analytical expressions of coverage probabilities in order to evaluate coverage performance in different tiers and investigate how it varies with the small cells' deployment density. By taking the fairness and user experience into consideration, we propose a disjoint channel allocation scheme and derive the system channel throughput for various tiers. Further, we formulate the energy efficiency optimization problem for multi-tier HetNets in terms of throughput performance and resource allocation fairness. To solve this problem, we devise a linear programming based approach to obtain the available area of the feasible solutions. System-level simulations demonstrate that the small cells' deployment density has a significant effect on the coverage performance and energy efficiency. Simulation results also reveal that there exits an optimal small cell base station (SBS) density ratio between pico-tier and femto-tier which can be applied to maximize the energy efficiency and at the same time enhance the system performance. Our findings provide guidance for the design of multi-tier HetNets for improving the coverage performance as well as the energy efficiency.
Xiao, Zhu; Liu, Hongjing; Havyarimana, Vincent; Li, Tong; Wang, Dong
2016-01-01
In this paper, we investigate the coverage performance and energy efficiency of multi-tier heterogeneous cellular networks (HetNets) which are composed of macrocells and different types of small cells, i.e., picocells and femtocells. By virtue of stochastic geometry tools, we model the multi-tier HetNets based on a Poisson point process (PPP) and analyze the Signal to Interference Ratio (SIR) via studying the cumulative interference from pico-tier and femto-tier. We then derive the analytical expressions of coverage probabilities in order to evaluate coverage performance in different tiers and investigate how it varies with the small cells’ deployment density. By taking the fairness and user experience into consideration, we propose a disjoint channel allocation scheme and derive the system channel throughput for various tiers. Further, we formulate the energy efficiency optimization problem for multi-tier HetNets in terms of throughput performance and resource allocation fairness. To solve this problem, we devise a linear programming based approach to obtain the available area of the feasible solutions. System-level simulations demonstrate that the small cells’ deployment density has a significant effect on the coverage performance and energy efficiency. Simulation results also reveal that there exits an optimal small cell base station (SBS) density ratio between pico-tier and femto-tier which can be applied to maximize the energy efficiency and at the same time enhance the system performance. Our findings provide guidance for the design of multi-tier HetNets for improving the coverage performance as well as the energy efficiency. PMID:27827917
Calculation of Rydberg energy levels for the francium atom
NASA Astrophysics Data System (ADS)
Huang, Shi-Zhong; Chu, Jin-Min
2010-06-01
Based on the weakest bound electron potential model theory, the Rydberg energy levels and quantum defects of the np2Po1/2 (n = 7-50) and np2Po3/2 (n = 7-50) spectrum series for the francium atom are calculated. The calculated results are in excellent agreement with the 48 measured levels, and 40 energy levels for highly excited states are predicted.
Schwartz, Jesse D.M.
2013-01-01
In the United States overall electrical generation capacity is expected to increase by 10-25 gigawatts (GW) per year to meet increases in demand. Wind energy is a key component of state and federal renewable energy standards, and central to the Department of Energy’s 20% by 2030 wind production goals. Increased wind energy development may present increased resource conflict with avian wildlife, and environmental permitting has been identified as a potential obstacle to expansion in the sector. ICF developed an analytical framework to help applicants and agencies examine potential impacts in support of facility siting and permitting. A key objective of our work was to develop a framework that is scalable from the local to the national level, and one that is generalizable across the different scales at which biological communities operate – from local influences to meta-populations. The intent was to allow natural resource managers to estimate the cumulative impacts of turbine strikes and habitat changes on long-term population performance in the context of a species demography, genetic potential, and life history. We developed three types of models based on our literature review and participation in the scientific review processes. First, the conceptual model was developed as a general description of the analytical framework. Second, we developed the analytical framework based on the relationships between concepts, and the functions presented in the scientific literature. Third, we constructed an application of the model by parameterizing the framework using data from and relevant to the Altamont Pass Wind Resource Area (APWRA), and an existing golden eagle population model. We developed managed source code, database create statements, and written documentation to allow for the reproduction of each phase of the analysis. ICF identified a potential template adaptive management system in the form of the US Fish & Wildlife Service (USFWS) Adaptive Harvest
How to Draw Energy Level Diagrams in Excitonic Solar Cells.
Zhu, X-Y
2014-07-03
Emerging photovoltaic devices based on molecular and nanomaterials are mostly excitonic in nature. The initial absorption of a photon in these materials creates an exciton that can subsequently dissociate in each material or at their interfaces to give charge carriers. Any attempt at mechanistic understanding of excitonic solar cells must start with drawing energy level diagrams. This seemingly elementary exercise, which is described in textbooks for inorganic solar cells, has turned out to be a difficult subject in the literature. The problem stems from conceptual confusion of single-particle energy with quasi-particle energy and the misleading practice of mixing the two on the same energy level diagram. Here, I discuss how to draw physically accurate energy diagrams in excitonic solar cells using only single-particle energies (ionization potentials and electron affinities) of both ground and optically excited states. I will briefly discuss current understanding on the electronic energy landscape responsible for efficient charge separation in excitonic solar cells.
NASA Technical Reports Server (NTRS)
Billings, Marcus Dwight; Fasanella, Edwin L. (Technical Monitor)
2002-01-01
Nonlinear dynamic finite element simulations were performed to aid in the design of an energy-absorbing impact sphere for a passive Earth Entry Vehicle (EEV) that is a possible architecture for the Mars Sample Return (MSR) mission. The MSR EEV concept uses an entry capsule and energy-absorbing impact sphere designed to contain and limit the acceleration of collected samples during Earth impact without a parachute. The spherical shaped impact sphere is composed of solid hexagonal and pentagonal foam-filled cells with hybrid composite, graphite-epoxy/Kevlar cell walls. Collected Martian samples will fit inside a smaller spherical sample container at the center of the EEV's cellular structure. Comparisons were made of analytical results obtained using MSC.Dytran with test results obtained from impact tests performed at NASA Langley Research Center for impact velocities from 30 to 40 m/s. Acceleration, velocity, and deformation results compared well with the test results. The correlated finite element model was then used for simulations of various off-nominal impact scenarios. Off-nominal simulations at an impact velocity of 40 m/s included a rotated cellular structure impact onto a flat surface, a cellular structure impact onto an angled surface, and a cellular structure impact onto the corner of a step.
Photon Activation Analysis—An Analytical Application Of High-Energy Electron Accelerators
NASA Astrophysics Data System (ADS)
Segebade, Christian R.; Goerner, Wolf
2009-03-01
Photon activation analysis (PAA) was introduced about contemporarily with the other activation analysis methods (neutron, NAA, and charged particle activation, CPAA). Nonetheless, for different reasons, PAA has been applied less frequently than the other techniques mentioned. The incident photon energy should exceed about 12 MeV (except in some special rare applications) so as to obtain appreciably high activity yields of the product nuclides. Thus, cyclic electron accelerators (LINACs or microtrons) are used for activation preferably. The predominant photonuclear reaction is of the (γ,n)-type. Thus, normally neutron-deficient nuclides are produced. These usually emit gamma rays, annihilation quanta and characteristic X-ray fluorescence, all of whom can be used for analytical evaluation. The spectrometry equipment is the same as used for the other activation techniques (semiconductor detectors, sodium iodide crystals in coincidence geometry). Being uncharged high energy photons have a large penetration power, thus do not suffer from strong matrix absorption. Although not having a detection power as large as in NAA (in the most cases), PAA offers several further convincing advantages, e.g. several elements not or hardly detectable by NAA can be analysed: Titanium, nickel, thallium, lead, bismuth and, in particular, the light elements carbon, nitrogen, oxygen, fluorine, phosphorus. Several typical applications will be described.
NASA Astrophysics Data System (ADS)
Wang, Bingbao; Guo, Wencheng; Yang, Jiandong
2017-06-01
Combined operating condition usually refers to the control operating condition under which the highest and lowest water levels occur in a surge tank of hydropower station. In this paper, with the basic equations of surge analysis and nonlinear vibrational asymptotic method, analytical expressions of the worst superimposition time of surge waves in an upstream surge tank under four typical combined operating conditions (i.e. load-acceptance-then-rejection, successive load rejection, successive load acceptance and load-rejection-then-acceptance) are derived firstly. Then using these expressions, the analytical extreme water levels are determined. The analytical solutions are verified with numerical simulation results. Finally, the effect of the hydraulic resistance coefficient of surge tank on the control operating condition is investigated. The results indicate that: The analytical solutions for determining extreme water levels in surge tank under various combined operating conditions are accurate due to the good agreements between the analytical results and the numerical results. With the increase of the hydraulic resistance coefficient of surge tank, the control operating condition for the highest water level shifts from load-acceptance-then-rejection condition to successive load rejection condition, and the control operating condition for the lowest water level shifts from load-rejection-then-acceptance condition to successive load acceptance condition.
Caregiver's education level and child's dental caries in African Americans: a path analytic study.
Heima, Masahiro; Lee, Wonik; Milgrom, Peter; Nelson, Suchita
2015-01-01
The objective of this study was to investigate the influence of caregiver education level on children's dental caries mediated by both caregiver and child oral health behaviors. Participants were 423 low-income African American kindergarteners and their caregivers who were part of a school-based randomized clinical trial. Path analysis tested the hypothesis that caregiver education level affected untreated dental caries and cumulative overall caries experience (decayed or filled teeth) through the mediating influence of frequency of dental visits, use of routine care, and frequency of toothbrushing for both the caregiver and the child. The results supported the hypothesis: caregivers who completed high school were 1.76 times more likely to visit dentists compared with those who did not complete high school (e(0.56) = 1.76, 95% CI: 1.03-2.99), which in turn was associated with 5.78 times greater odds of dental visits among their children (e(1.76) = 5.78, 95% CI: 3.53-9.48). Children's dental visits, subsequently, were associated with 26% fewer untreated decayed teeth compared with children without dental visits (e(-0.31) = 0.74, 95% CI: 0.60-0.91). However, this path was not present in the model with overall caries experience. Additionally, caregiver education level was directly associated with 34% less untreated decayed teeth (e(-0.42) = 0.66, 95% CI: 0.54-0.79) and 28% less decayed or filled teeth (e(-0.32) = 0.72, 95% CI: 0.60-0.88) among the children. This study overcomes important conceptual and analytic limitations in the existing literature. The findings confirm the role of caregiver education in child dental caries and indicate that caregiver's behavioral factors are important mediators of child oral health.
An analytical solution of groundwater level fluctuation in a U-shaped leaky coastal aquifer
NASA Astrophysics Data System (ADS)
Huang, Fu-Kuo; Chuang, Mo-Hsiung; Wang, Shu-chuan
2017-04-01
Tide-induced groundwater level fluctuations in coastal aquifers have attracted much attention in past years, especially for the issues associated with the impact of the coastline shape, multi-layered leaky aquifer system, and anisotropy of aquifers. In this study, a homogeneous but anisotropic multi-layered leaky aquifer system with U-shaped coastline is considered, where the subsurface system consisting of an unconfined aquifer, a leaky confined aquifer, and a semi-permeable layer between them. The analytical solution of the model obtained herein may be considered as an extended work of two solutions; one was developed by Huang et al. (Huang et al. Tide-induced groundwater level fluctuation in a U-shaped coastal aquifer, J. Hydrol. 2015; 530: 291-305) for two-dimensional interacting tidal waves bounded by three water-land boundaries while the other was by Li and Jiao (Li and Jiao. Tidal groundwater level fluctuations in L-shaped leaky coastal aquifer system, J. Hydrol. 2002; 268: 234-243) for two-dimensional interacting tidal waves of leaky coastal aquifer system adjacent to a cross-shore estuary. In this research, the effects of leakage and storativity of the semi-permeable layer on the amplitude and phase shift of the tidal head fluctuation, and the influence of anisotropy of the aquifer are all examined for the U-shaped leaky coastal aquifer. Some existing solutions in literatures can be regarded as the special cases of the present solution if the aquifer system is isotropic and non-leaky. The results obtained will be beneficial to coastal development and management for water resources.
Caregiver's education level and child's dental caries in African Americans: A path analytic study
Heima, Masahiro; Lee, Wonik; Milgrom, Peter; Nelson, Suchitra
2015-01-01
The objective of this study was to investigate the influence of caregiver education level on children's dental caries mediated by both caregiver and child oral health behaviors. Participants were 423 low-income African American kindergarteners and their caregivers who were part of a school-based randomized clinical trial. Path analysis tested the hypothesis that caregiver education level affected untreated dental caries and cumulative overall caries experience (decayed or filled teeth) through the mediating influence of frequency of dental visits, use of routine care, and frequency of toothbrushing for both caregiver and child. The results supported the hypothesis: Caregivers who completed high school were 1.76 times more likely to visit dentists themselves compared with those who did not complete high school (e0.56=1.76, 95%CI: 1.03-2.99), which in turn was associated with 5.78 times greater odds of dental visits among their children (e1.76=5.78, 95%CI: 3.53-9.48). Children's dental visits, subsequently, were associated with 26% fewer untreated decayed teeth compared with children without dental visits (e-0.31=0.74, 95%CI: 0.60-0.91). However, this path was not present in the model with overall caries experience. Additionally, caregiver education level was directly associated with 34% less untreated decayed teeth (e-0.42=0.66, 95% CI: 0.54-0.79) and 28% less decayed or filled teeth (e-0.32=0.72, 95%CI: 0.60-0.88) among the children. This study overcomes important conceptual and analytic limitations in the existing literature. The findings confirm the role of caregiver education in child dental caries and indicate that caregiver's behavioral factors are important mediators of child oral health. PMID:25661111
Analytic spectrum of relic gravitational waves modified by neutrino free streaming and dark energy
Miao, H. X.; Zhang, Y.
2007-05-15
We include the effect of neutrino free streaming into the spectrum of relic gravitational waves (RGWs) in the currently accelerating universe. For the realistic case of a varying fractional neutrino energy density and a nonvanishing derivative of the mode function at the neutrino decoupling, the integro-differential equation of RGWs is solved by a perturbation method for the period from the neutrino decoupling to the matter-dominant stage. Incorporating it into the analytic solution of RGWs for the whole history of expansion of the universe, the analytic solution of RGWs is obtained, evolving from inflation up to the current acceleration. The resulting spectrum of RGWs covers the whole range of frequency (10{sup -19}-10{sup 10}) Hz and improves the previous results. It is found that neutrino free streaming causes a reduction of the spectral amplitude by {approx}20% in the range (10{sup -16}-10{sup -10}) Hz, and leaves the other portion of the spectrum almost unchanged. This agrees with the earlier numerical calculations. Examination is made on the difference between the accelerating and nonaccelerating models, and our analysis shows that the ratio of the spectral amplitude in the accelerating {lambda}CDM model over that in the CDM model is {approx}0.7, and within the various accelerating models of {omega}{sub {lambda}}>{omega}{sub m} the spectral amplitude is proportional to {omega}{sub m}/{omega}{sub {lambda}} for the whole range of frequency. Comparison with LIGO S5 run sensitivity shows that RGWs are not yet detectable by the present LIGO, and in the future LISA may be able to detect RGWs in some inflationary models.
Analytic model for low energy excitation states and phase transitions in spin-ice systems
NASA Astrophysics Data System (ADS)
López-Bara, F. I.; López-Aguilar, F.
2017-04-01
Low energy excitation states in magnetic structures of the so-called spin-ices are produced via spin flips among contiguous tetrahedra of their crystal structure. These spin flips generate entities which mimic magnetic dipoles in every two tetrahedra according to the dumbbell model. When the temperature increases, the spin-flip processes are transmitted in the lattice, generating so-called Dirac strings, which constitute structural entities that can present mimetic behavior similar to that of magnetic monopoles. In recent studies of both specific heat and ac magnetic susceptibility, two (even possibly three) phases have been shown to vary the temperature. The first of these phases presents a sharp peak in the specific heat and another phase transition occurs for increasing temperature whose peak is broader than that of the former phase. The sharp peak occurs when there are no free individual magnetic charges and temperature of the second phase transition coincides with the maximum proliferation of free deconfined magnetic charges. In the present paper, we propose a model for analyzing the low energy excitation many-body states of these spin-ice systems. We give analytical formulas for the internal energy, specific heat, entropy and their temperature evolution. We study the description of the possible global states via the nature and structure of their one-body components by means of the thermodynamic functions. Below 0.37 K, the Coulomb-like magnetic charge interaction can generate a phase transition to a condensation of pole–antipole pairs, possibly having Bose–Einstein structure which is responsible for the sharp peak of the first phase transition. When there are sufficient free positive and negative charges, the system tends to behave as a magnetic plasma, which implies the broader peak in the specific heat appearing at higher temperature than the sharper experimental peak.
Gary, S Peter; Winske, Dan; Wu, Pin; Schwadron, N A; Lee, M
2009-01-01
The Los Alamos hybrid simulation code is used to examine heating and the partition of dissipation energy at the perpendicular heliospheric termination shock in the presence of pickup ions. The simulations are one-dimensional in space but three-dimensional in field and velocity components, and are carried out for a range of values of pickup ion relative density. Results from the simulations show that because the solar wind ions are relatively cold upstream, the temperature of these ions is raised by a relatively larger factor than the temperature of the pickup ions. An analytic model for energy partition is developed on the basis of the Rankine-Hugoniot relations and a polytropic energy equation. The polytropic index {gamma} used in the Rankine-Hugoniot relations is varied to improve agreement between the model and the simulations concerning the fraction of downstream heating in the pickup ions as well as the compression ratio at the shock. When the pickup ion density is less than 20%, the polytropic index is about 5/3, whereas for pickup ion densities greater than 20%, the polytropic index tends toward 2.2, suggesting a fundamental change in the character of the shock, as seen in the simulations, when the pickup ion density is large. The model and the simulations both indicate for the upstream parameters chosen for Voyager 2 conditions that the pickup ion density is about 25% and the pickup ions gain the larger share (approximately 90%) of the downstream thermal pressure, consistent with Voyager 2 observations near the shock.
Analytic model for low energy excitation states and phase transitions in spin-ice systems.
López-Bara, F I; López-Aguilar, F
2017-04-20
Low energy excitation states in magnetic structures of the so-called spin-ices are produced via spin flips among contiguous tetrahedra of their crystal structure. These spin flips generate entities which mimic magnetic dipoles in every two tetrahedra according to the dumbbell model. When the temperature increases, the spin-flip processes are transmitted in the lattice, generating so-called Dirac strings, which constitute structural entities that can present mimetic behavior similar to that of magnetic monopoles. In recent studies of both specific heat and ac magnetic susceptibility, two (even possibly three) phases have been shown to vary the temperature. The first of these phases presents a sharp peak in the specific heat and another phase transition occurs for increasing temperature whose peak is broader than that of the former phase. The sharp peak occurs when there are no free individual magnetic charges and temperature of the second phase transition coincides with the maximum proliferation of free deconfined magnetic charges. In the present paper, we propose a model for analyzing the low energy excitation many-body states of these spin-ice systems. We give analytical formulas for the internal energy, specific heat, entropy and their temperature evolution. We study the description of the possible global states via the nature and structure of their one-body components by means of the thermodynamic functions. Below 0.37 K, the Coulomb-like magnetic charge interaction can generate a phase transition to a condensation of pole-antipole pairs, possibly having Bose-Einstein structure which is responsible for the sharp peak of the first phase transition. When there are sufficient free positive and negative charges, the system tends to behave as a magnetic plasma, which implies the broader peak in the specific heat appearing at higher temperature than the sharper experimental peak.
Sheehan, P; Ricks, R; Ripple, S; Paustenbach, D
1992-01-01
Hexavalent chromium, Cr(VI), has been classified as a human respiratory carcinogen. Airborne Cr(VI) emissions are associated with a number of industrial sources including metal plating, tanning, chromite ore processing, and spray painting operations; combustion sources such as automobiles and incinerators; and fugitive dusts from contaminated soil. There has been considerable interest within industry and the regulatory community to assess the potential cancer risks of workers exposed to Cr(VI) at levels substantially below the threshold limit value (TLV) of 50 micrograms/m3. To date, only the workplace sampling and analytical method (National Institute for Occupational Safety and Health [NIOSH] Method 7600) has been validated for measuring airborne Cr(VI), and it can accurately measure concentrations only as low as 500 ng/m3. This paper describes the field evaluation of a sampling and analytical method for the quantitation of airborne Cr(VI) at concentrations 5000 times lower than the current standard method (as low as 0.1 ng/m3). The collection method uses three 500-mL Greenberg-Smith impingers in series, operated at 15 Lpm for 24 hr. All three impingers are filled with 200 mL of a slightly alkaline (pH approximately 8) sodium bicarbonate buffer solution. The results of validation tests showed that both Cr(VI) and trivalent chromium, Cr(III), were stable in the collection medium and that samples may be stored for up to 100 days without appreciable loss of Cr(VI). Method precision based on the pooled coefficient of variation for replicate samples was 10.4%, and method accuracy based on the mean percent recovery of spiked samples was 94%. Both the precision and accuracy of the impinger method were within NIOSH criteria. This method could be used to measure ambient concentrations of Cr(VI) in the workplace caused by fugitive emissions from manufacturing processes or chromium-contaminated soils at workplace concentrations well below the current TLV (50 micrograms/m3
Efficiencies of thermodynamics when temperature-dependent energy levels exist.
Yamano, Takuya
2016-03-14
Based on a generalized form of the second law of thermodynamics, in which the temperature-dependent energy levels of a system are appropriately included in entropy generation, we show that the effect reasonably appears in efficiencies of thermodynamic processes.
Housing Electrons: Relating Quantum Numbers, Energy Levels, and Electron Configurations.
ERIC Educational Resources Information Center
Garofalo, Anthony
1997-01-01
Presents an activity that combines the concepts of quantum numbers and probability locations, energy levels, and electron configurations in a concrete, hands-on way. Uses model houses constructed out of foam board and colored beads to represent electrons. (JRH)
"Piekara's Chair": Mechanical Model for Atomic Energy Levels.
ERIC Educational Resources Information Center
Golab-Meyer, Zofia
1991-01-01
Uses the teaching method of models or analogies, specifically the model called "Piekara's chair," to show how teaching classical mechanics can familiarize students with the notion of energy levels in atomic physics. (MDH)
"Piekara's Chair": Mechanical Model for Atomic Energy Levels.
ERIC Educational Resources Information Center
Golab-Meyer, Zofia
1991-01-01
Uses the teaching method of models or analogies, specifically the model called "Piekara's chair," to show how teaching classical mechanics can familiarize students with the notion of energy levels in atomic physics. (MDH)
Classification of Cm i energy levels using counterpropagation neural networks
NASA Astrophysics Data System (ADS)
Peterson, Keith L.
1990-03-01
Two different types of counterpropagation neural networks are applied to the problem of classifying unknown Cm i energy levels. Four features-energy level, angular momentum, g factor, and isotope shift-are used to describe each level. One type of network is trained at the 100% level, while the other type is trained in excess of 96%. Performance on test sets is not as good, ranging from 81.2% to 93.7%. These results equal or surpass pattern recognition results obtained in an earlier study. Classifications for 12 odd-parity unknowns and 42 even-parity unknowns are also obtained and compared with the previous pattern recognition predictions.
Adamovich, Igor V.
2014-04-15
A three-dimensional, nonperturbative, semiclassical analytic model of vibrational energy transfer in collisions between a rotating diatomic molecule and an atom, and between two rotating diatomic molecules (Forced Harmonic Oscillator–Free Rotation model) has been extended to incorporate rotational relaxation and coupling between vibrational, translational, and rotational energy transfer. The model is based on analysis of semiclassical trajectories of rotating molecules interacting by a repulsive exponential atom-to-atom potential. The model predictions are compared with the results of three-dimensional close-coupled semiclassical trajectory calculations using the same potential energy surface. The comparison demonstrates good agreement between analytic and numerical probabilities of rotational and vibrational energy transfer processes, over a wide range of total collision energies, rotational energies, and impact parameter. The model predicts probabilities of single-quantum and multi-quantum vibrational-rotational transitions and is applicable up to very high collision energies and quantum numbers. Closed-form analytic expressions for these transition probabilities lend themselves to straightforward incorporation into DSMC nonequilibrium flow codes.
Emfietzoglou, D.; Kyriakou, I.; Garcia-Molina, R.; Abril, I.; Kostarelos, K.
2010-09-15
We have determined ''effective'' Bethe coefficients and the mean excitation energy of stopping theory (I-value) for multiwalled carbon nanotubes (MWCNTs) and single-walled carbon nanotube (SWCNT) bundles based on a sum-rule constrained optical-data model energy loss function with improved asymptotic properties. Noticeable differences between MWCNTs, SWCNT bundles, and the three allotropes of carbon (diamond, graphite, glassy carbon) are found. By means of Bethe's asymptotic approximation, the inelastic scattering cross section, the electronic stopping power, and the average energy transfer to target electrons in a single inelastic collision, are calculated analytically for a broad range of electron and proton beam energies using realistic excitation parameters.
Temperature dependent energy levels of methylammonium lead iodide perovskite
Foley, Benjamin J.; Marlowe, Daniel L.; Choi, Joshua J. E-mail: mgupta@virginia.edu; Sun, Keye; Gupta, Mool C. E-mail: mgupta@virginia.edu; Saidi, Wissam A.; Scudiero, Louis E-mail: mgupta@virginia.edu
2015-06-15
Temperature dependent energy levels of methylammonium lead iodide are investigated using a combination of ultraviolet photoemission spectroscopy and optical spectroscopy. Our results show that the valence band maximum and conduction band minimum shift down in energy by 110 meV and 77 meV as temperature increases from 28 °C to 85 °C. Density functional theory calculations using slab structures show that the decreased orbital splitting due to thermal expansion is a major contribution to the experimentally observed shift in energy levels. Our results have implications for solar cell performance under operating conditions with continued sunlight exposure and increased temperature.
NASA Astrophysics Data System (ADS)
Tsukioka, Y.; Nakada, H.
2017-07-01
The nuclear symmetry energy is defined by the second derivative of the energy per nucleon with respect to the proton-neutron asymmetry, and is sometimes approximated by the energy difference between the neutron matter and the symmetric matter. The accuracy of this approximation is assessed analytically and numerically within the Hartree-Fock theory using effective interactions. By decomposing the nuclear-matter energy, the relative error of each term is expressed analytically; it is constant or is a single-variable function determined by the function type. The full errors are evaluated for several effective interactions, by inserting values for the parameters. Although the errors stay within 10 % up to twice the normal density irrespective of the interactions, at higher densities the accuracy of the approximation significantly depends on the interactions.
An analytic mapping of oligomer potential energy surfaces to an effective Frenkel model
Binder, Robert; Römer, Sarah E-mail: burghardt@chemie.uni-frankfurt.de; Wahl, Jan; Burghardt, Irene E-mail: burghardt@chemie.uni-frankfurt.de
2014-07-07
While the use of Frenkel-type models for semiconducting polymer assemblies and related molecular aggregates is well established, the direct parametrization of such models based on electronic structure data is attempted less frequently. In this work, we develop a systematic mapping procedure which is adapted to J-type and H-type homo-aggregate systems. The procedure is based upon the analytic solution of an inverse eigenvalue problem for an effective Frenkel Hamiltonian with nearest-neighbor couplings. Vibronic interactions are included for both site-local and site-correlated modes. For illustration, an application is presented to the excited-state ab initio potential energy surfaces (PESs) of an oligothiophene octamer. The procedure performs a pointwise mapping of the PESs of oligomers of arbitrary chain length n, provided that the electronic ground state and any two of the n lowest adiabatic states of the excitonic manifold of interest are known. These three states are reproduced exactly by the procedure while the remaining n − 2 states of the excitonic manifold can be predicted. Explicit conditions are derived permitting to verify whether a given data set is compatible with the effective Frenkel model under study.
Analytical Model for Mean Flow and Fluxes of Momentum and Energy in Very Large Wind Farms
NASA Astrophysics Data System (ADS)
Markfort, Corey D.; Zhang, Wei; Porté-Agel, Fernando
2017-08-01
As wind-turbine arrays continue to be installed and the array size continues to grow, there is an increasing need to represent very large wind-turbine arrays in numerical weather prediction models, for wind-farm optimization, and for environmental assessment. We propose a simple analytical model for boundary-layer flow in fully-developed wind-turbine arrays, based on the concept of sparsely-obstructed shear flows. In describing the vertical distribution of the mean wind speed and shear stress within wind farms, our model estimates the mean kinetic energy harvested from the atmospheric boundary layer, and determines the partitioning between the wind power captured by the wind turbines and that absorbed by the underlying land or water. A length scale based on the turbine geometry, spacing, and performance characteristics, is able to estimate the asymptotic limit for the fully-developed flow through wind-turbine arrays, and thereby determine if the wind-farm flow is fully developed for very large turbine arrays. Our model is validated using data collected in controlled wind-tunnel experiments, and its usefulness for the prediction of wind-farm performance and optimization of turbine-array spacing are described. Our model may also be useful for assessing the extent to which the extraction of wind power affects the land-atmosphere coupling or air-water exchange of momentum, with implications for the transport of heat, moisture, trace gases such as carbon dioxide, methane, and nitrous oxide, and ecologically important oxygen.
NMR chemical shift as analytical derivative of the Helmholtz free energy.
Van den Heuvel, Willem; Soncini, Alessandro
2013-02-07
We present a theory for the temperature-dependent nuclear magnetic shielding tensor of molecules with arbitrary electronic structure. The theory is a generalization of Ramsey's theory for closed-shell molecules. The shielding tensor is defined as a second derivative of the Helmholtz free energy of the electron system in equilibrium with the applied magnetic field and the nuclear magnetic moments. This derivative is analytically evaluated and expressed as a sum over states formula. Special consideration is given to a system with an isolated degenerate ground state for which the size of the degeneracy and the composition of the wave functions are arbitrary. In this case, the paramagnetic part of the shielding tensor is expressed in terms of the g and A tensors of the electron paramagnetic resonance spin Hamiltonian of the degenerate state. As an illustration of the proposed theory, we provide an explicit formula for the paramagnetic shift of the central lanthanide ion in endofullerenes Ln@C(60), with Ln = Ce(3+), Nd(3+), Sm(3+), Dy(3+), Er(3+), and Yb(3+), where the ground state can be a strongly spin-orbit coupled icosahedral sextet for which the paramagnetic shift cannot be described by previous theories.
An analytic mapping of oligomer potential energy surfaces to an effective Frenkel model.
Binder, Robert; Römer, Sarah; Wahl, Jan; Burghardt, Irene
2014-07-07
While the use of Frenkel-type models for semiconducting polymer assemblies and related molecular aggregates is well established, the direct parametrization of such models based on electronic structure data is attempted less frequently. In this work, we develop a systematic mapping procedure which is adapted to J-type and H-type homo-aggregate systems. The procedure is based upon the analytic solution of an inverse eigenvalue problem for an effective Frenkel Hamiltonian with nearest-neighbor couplings. Vibronic interactions are included for both site-local and site-correlated modes. For illustration, an application is presented to the excited-state ab initio potential energy surfaces (PESs) of an oligothiophene octamer. The procedure performs a pointwise mapping of the PESs of oligomers of arbitrary chain length n, provided that the electronic ground state and any two of the n lowest adiabatic states of the excitonic manifold of interest are known. These three states are reproduced exactly by the procedure while the remaining n - 2 states of the excitonic manifold can be predicted. Explicit conditions are derived permitting to verify whether a given data set is compatible with the effective Frenkel model under study.
Taguchi, Katsuyuki; Frey, Eric C.; Wang, Xiaolan; Iwanczyk, Jan S.; Barber, William C.
2010-01-01
Purpose: Recently, novel CdTe photon counting x-ray detectors (PCXDs) with energy discrimination capabilities have been developed. When such detectors are operated under a high x-ray flux, however, coincident pulses distort the recorded energy spectrum. These distortions are called pulse pileup effects. It is essential to compensate for these effects on the recorded energy spectrum in order to take full advantage of spectral information PCXDs provide. Such compensation can be achieved by incorporating a pileup model into the image reconstruction process for computed tomography, that is, as a part of the forward imaging process, and iteratively estimating either the imaged object or the line integrals using, e.g., a maximum likelihood approach. The aim of this study was to develop a new analytical pulse pileup model for both peak and tail pileup effects for nonparalyzable detectors. Methods: The model takes into account the following factors: The bipolar shape of the pulse, the distribution function of time intervals between random events, and the input probability density function of photon energies. The authors used Monte Carlo simulations to evaluate the model. Results: The recorded spectra estimated by the model were in an excellent agreement with those obtained by Monte Carlo simulations for various levels of pulse pileup effects. The coefficients of variation (i.e., the root mean square difference divided by the mean of measurements) were 5.3%–10.0% for deadtime losses of 1%–50% with a polychromatic incident x-ray spectrum. Conclusions: The proposed pulse pileup model can predict recorded spectrum with relatively good accuracy. PMID:20879558
Energy index decomposition methodology at the plant level
NASA Astrophysics Data System (ADS)
Kumphai, Wisit
Scope and method of study. The dissertation explores the use of a high level energy intensity index as a facility-level energy performance monitoring indicator with a goal of developing a methodology for an economically based energy performance monitoring system that incorporates production information. The performance measure closely monitors energy usage, production quantity, and product mix and determines the production efficiency as a part of an ongoing process that would enable facility managers to keep track of and, in the future, be able to predict when to perform a recommissioning process. The study focuses on the use of the index decomposition methodology and explored several high level (industry, sector, and country levels) energy utilization indexes, namely, Additive Log Mean Divisia, Multiplicative Log Mean Divisia, and Additive Refined Laspeyres. One level of index decomposition is performed. The indexes are decomposed into Intensity and Product mix effects. These indexes are tested on a flow shop brick manufacturing plant model in three different climates in the United States. The indexes obtained are analyzed by fitting an ARIMA model and testing for dependency between the two decomposed indexes. Findings and conclusions. The results concluded that the Additive Refined Laspeyres index decomposition methodology is suitable to use on a flow shop, non air conditioned production environment as an energy performance monitoring indicator. It is likely that this research can be further expanded in to predicting when to perform a recommissioning process.
Navas, María José; Asuero, Agustín García; Jiménez, Ana María
2016-01-01
Energy dispersive X-ray fluorescence spectrometry (EDXRF) as an analytical technique in studies of ancient coins is summarized and reviewed. Specific EDXRF applications in historical studies, in studies of the corrosion of coins, and in studies of the optimal working conditions of some laser-based treatment for the cleaning of coins are described.
Lillian, D.; Bottrell, D.
1993-12-31
The U.S. Department of Energy`s (DOE`s) Office of Environmental Restoration and Waste Management (EM) has been tasked with addressing environmental contamination and waste problems facing the Department. A key element of any environmental restoration or waste management program is environmental data. An effective and efficient sampling and analysis program is required to generate credible environmental data. The bases for DOE`s EM Analytical Services Program (ASP) are contained in the charter and commitments in Secretary of Energy Notice SEN-13-89, EM program policies and requirements, and commitments to Congress and the Office of Inspector General (IG). The Congressional commitment by DOE to develop and implement an ASP was in response to concerns raised by the Chairman of the Congressional Environment, Energy, and Natural Resources Subcommittee, and the Chairman of the Congressional Oversight and Investigations Subcommittee of the Committee on Energy and Commerce, regarding the production of analytical data. The development and implementation of an ASP also satisfies the IG`s audit report recommendations on environmental analytical support, including development and implementation of a national strategy for acquisition of quality sampling and analytical services. These recommendations were endorsed in Departmental positions, which further emphasize the importance of the ASP to EM`s programs. In September 1990, EM formed the Laboratory Management Division (LMD) in the Office of Technology Development to provide the programmatic direction needed to establish and operate an EM-wide ASP program. In January 1992, LMD issued the {open_quotes}Analytical Services Program Five-Year Plan.{close_quotes} This document described LMD`s strategy to ensure the production of timely, cost-effective, and credible environmental data. This presentation describes the overall LMD Analytical Services Program and, specifically, the various QA programs.
Intrinsic deep hole trap levels in Cu2O with self-consistent repulsive Coulomb energy
NASA Astrophysics Data System (ADS)
Huang, Bolong
2016-03-01
The large error of the DFT+U method on full-filled shell metal oxides is due to the residue of self-energy from the localized d orbitals of cations and p orbitals of the anions. U parameters are selfconsistently found to achieve the analytical self-energy cancellation. The improved band structures based on relaxed lattices of Cu2O are shown based on minimization of self-energy error. The experimentally reported intrinsic p-type trap levels are contributed by both Cu-vacancy and the O-interstitial defects in Cu2O. The latter defect has the lowest formation energy but contributes a deep hole trap level while the Cuvacancy has higher energy cost but acting as a shallow acceptor. Both present single-particle levels spread over nearby the valence band edge, consistent to the trend of defects transition levels. By this calculation approach, we also elucidated the entanglement of strong p-d orbital coupling to unravel the screened Coulomb potential of fully filled shells.
Espinosa-Garcia, J; Corchado, J C
2010-04-01
Based on accurate electronic structure calculations, a new analytical potential energy surface (PES) was fitted to simultaneously describe the hydrogen abstraction reaction from ammonia by a hydrogen atom, and the ammonia inversion. Using a wide spectrum of properties of the reactive system (equilibrium geometries, vibrational frequencies, and relative energies of the stationary points, topology of the reaction paths, and points on the reaction swaths) as reference, the resulting analytical PES reproduces reasonably well the input ab initio information obtained at the CCSD(T)/cc-pVTZ level, which represents a severe test for the new surface. As a first application, on this analytical PES we perform an extensive kinetics study using variational transition-state theory with semiclassical transmission coefficients over a wide temperature range, 200-2000 K. For the hydrogen abstraction reaction, the forward rate constants reproduce the experimental measurements, while the reverse ones are slightly underestimated. Another severe test of the new surface is the analysis of the kinetic isotope effects (KIEs). The KIEs between unsubstituted and all deuterated reactions agree with experiment in the common temperature range. For the ammonia inversion reaction, the splitting of the degenerate vibrational levels of the double well due to the tunneling contribution, which is very important in this reaction representing 93% of the reactivity at 200 K, was calculated for the NH(3) and ND(3) species. The values found were 3.6 and 0.37 cm(-1), respectively, which although higher than experimental values, reproduce the experimental behavior on isotopic substitution.
Examining the energy cost and intensity level of prenatal yoga.
Peters, Nathan Anthony; Schlaff, Rebecca A
2016-01-01
A popular form of pregnancy physical activity (PA) is prenatal yoga. However, little is known about the intensity and energy cost of this practice. To examine the energy cost and intensity level of prenatal yoga. Pregnant women in a prenatal yoga class (n = 19) wore a Sense Wear Armband during eleven 60 min classes each, and self-reported demographic variables, height and weight, prepregnancy weight, and PA behaviors and beliefs. Sense Wear Armband data included kilocalories, metabolic equivalent (MET) values, and time spent in various intensities. Descriptive statistics and frequencies were utilized to describe energy expenditure and intensity. Energy expenditure averaged 109 ± 8 kcals, and the average MET value was 1.5 ± 0.02. On average, 93% and 7% of classes were sedentary and moderate intensity PA, respectively. Time spent in a prenatal yoga class was considered to be primarily a sedentary activity. Future research should utilize larger samples, practice type, and skill level to increase generalizability.
NASA Astrophysics Data System (ADS)
Tso, C. P.; Chan, B. K.; Hashim, M. A.
1991-04-01
Analytical solutions are presented to the near-neutral atmospheric surface energy balance with the new approach of including the participation of heat storage in the building substrate. Analytical solutions are also presented for the first time for the case without heat storage effect. By a linearization process, the governing equations are simplified to a set of time-dependent, linear, first-order equations from which explicit solutions are readily obtainable. The results compare well with those obtained by numerical solutions upon the set without linearization when applied to the tropical city of Kuala Lumpur, Malaysia.
NASA Astrophysics Data System (ADS)
Polyansky, Oleg L.; Ovsyannikov, Roman I.; Kyuberis, Aleksandra A.; Lodi, Lorenzo; Tennyson, Jonathan; Yachmenev, Andrey; Yurchenko, Sergei N.; Zobov, Nikolai F.
2016-09-01
An ab initio potential energy surface (PES) for gas-phase ammonia NH3 has been computed using the methodology pioneered for water (Polyansky et al., 2013). Multireference configuration interaction calculations are performed at about 50 000 points using the aug-cc-pCVQZ and aug-cc-pCV5Z basis sets and basis set extrapolation. Relativistic and adiabatic surfaces are also computed. The points are fitted to a suitable analytical form, producing the most accurate ab initio PES for this molecule available. The rotation-vibration energy levels are computed using nuclear motion program TROVE in both linearised and curvilinear coordinates. Better convergence is obtained using curvilinear coordinates. Our results are used to assign the visible spectrum of 14NH3 recorded by Coy and Lehmann (1986). Rotation-vibration energy levels for the isotopologues NH2D, NHD2, ND3 and 15NH3 are also given. An ab initio value for the dissociation energy D0 of 14NH3 is also presented.
1993-07-22
weighted averages of specific energy and lineal energy are obtained. These microdosimetric quantities are useful for analyzing energy distributions...41 b. Specific Energy and the Two Component Model ................. 44 2. Lineal Energy Related Quantities...46 a. Definition and Background .............................. 46 b. Lineal Energy and the Two Component Model ................. 49
Tyuterev, Vladimir G; Kochanov, Roman V; Tashkun, Sergey A; Holka, Filip; Szalay, Péter G
2013-10-07
An accurate description of the complicated shape of the potential energy surface (PES) and that of the highly excited vibration states is of crucial importance for various unsolved issues in the spectroscopy and dynamics of ozone and remains a challenge for the theory. In this work a new analytical representation is proposed for the PES of the ground electronic state of the ozone molecule in the range covering the main potential well and the transition state towards the dissociation. This model accounts for particular features specific to the ozone PES for large variations of nuclear displacements along the minimum energy path. The impact of the shape of the PES near the transition state (existence of the "reef structure") on vibration energy levels was studied for the first time. The major purpose of this work was to provide accurate theoretical predictions for ozone vibrational band centres at the energy range near the dissociation threshold, which would be helpful for understanding the very complicated high-resolution spectra and its analyses currently in progress. Extended ab initio electronic structure calculations were carried out enabling the determination of the parameters of a minimum energy path PES model resulting in a new set of theoretical vibrational levels of ozone. A comparison with recent high-resolution spectroscopic data on the vibrational levels gives the root-mean-square deviations below 1 cm(-1) for ozone band centres up to 90% of the dissociation energy. New ab initio vibrational predictions represent a significant improvement with respect to all previously available calculations.
Monge-Palacios, M; Corchado, J C; Espinosa-Garcia, J
2013-06-07
To understand the reactivity and mechanism of the OH + NH3 → H2O + NH2 gas-phase reaction, which evolves through wells in the entrance and exit channels, a detailed dynamics study was carried out using quasi-classical trajectory calculations. The calculations were performed on an analytical potential energy surface (PES) recently developed by our group, PES-2012 [Monge-Palacios et al. J. Chem. Phys. 138, 084305 (2013)]. Most of the available energy appeared as H2O product vibrational energy (54%), reproducing the only experimental evidence, while only the 21% of this energy appeared as NH2 co-product vibrational energy. Both products appeared with cold and broad rotational distributions. The excitation function (constant collision energy in the range 1.0-14.0 kcal mol(-1)) increases smoothly with energy, contrasting with the only theoretical information (reduced-dimensional quantum scattering calculations based on a simplified PES), which presented a peak at low collision energies, related to quantized states. Analysis of the individual reactive trajectories showed that different mechanisms operate depending on the collision energy. Thus, while at high energies (E(coll) ≥ 6 kcal mol(-1)) all trajectories are direct, at low energies about 20%-30% of trajectories are indirect, i.e., with the mediation of a trapping complex, mainly in the product well. Finally, the effect of the zero-point energy constraint on the dynamics properties was analyzed.
THE IMPORTANCE OF PROPER INTENSITY CALIBRATION FOR RAMAN ANALYSIS OF LOW-LEVEL ANALYTES IN WATER
Modern dispersive Raman spectroscopy offers unique advantages for the analysis of low-concentration analytes in aqueous solution. However, we have found that proper intensity calibration is critical for obtaining these benefits. This is true not only for producing spectra with ...
Knowledge, Skills, and Abilities for Entry-Level Business Analytics Positions: A Multi-Method Study
ERIC Educational Resources Information Center
Cegielski, Casey G.; Jones-Farmer, L. Allison
2016-01-01
It is impossible to deny the significant impact from the emergence of big data and business analytics on the fields of Information Technology, Quantitative Methods, and the Decision Sciences. Both industry and academia seek to hire talent in these areas with the hope of developing organizational competencies. This article describes a multi-method…
THE IMPORTANCE OF PROPER INTENSITY CALIBRATION FOR RAMAN ANALYSIS OF LOW-LEVEL ANALYTES IN WATER
Modern dispersive Raman spectroscopy offers unique advantages for the analysis of low-concentration analytes in aqueous solution. However, we have found that proper intensity calibration is critical for obtaining these benefits. This is true not only for producing spectra with ...
Knowledge, Skills, and Abilities for Entry-Level Business Analytics Positions: A Multi-Method Study
ERIC Educational Resources Information Center
Cegielski, Casey G.; Jones-Farmer, L. Allison
2016-01-01
It is impossible to deny the significant impact from the emergence of big data and business analytics on the fields of Information Technology, Quantitative Methods, and the Decision Sciences. Both industry and academia seek to hire talent in these areas with the hope of developing organizational competencies. This article describes a multi-method…
ERIC Educational Resources Information Center
Chigisheva, Oksana; Bondarenko, Anna; Soltovets, Elena
2017-01-01
The paper provides analytical insights into highly acute issues concerning preparation and adoption of Qualifications Frameworks being an adequate response to the growing interactions at the global labor market and flourishing of knowledge economy. Special attention is paid to the analyses of transnational Meta Qualifications Frameworks (A…
Blokhintsev, L. D. Savin, D. A.
2016-05-15
An exactly solvable potential model is used to study the possibility of deducing information about the features of bound states for the system under consideration (binding energies and asymptotic normalization coefficients) on the basis of data on continuum states. The present analysis is based on an analytic approximation and on the subsequent continuation of a partial-wave scattering function from the region of positive energies to the region of negative energies. Cases where the system has one or two bound states are studied. The α+d and α+{sup 12}C systems are taken as physical examples. In the case of one bound state, the scattering function is a smooth function of energy, and the procedure of its analytic continuation for different polynomial approximations leads to close results, which are nearly coincident with exact values. In the case of two bound states, the scattering function has two poles—one in the region of positive energies and the other in the region of negative energies between the energies corresponding to the two bound states in question. Padéapproximants are used to reproduce these poles. The inclusion of these poles proves to be necessary for correctly describing the properties of the bound states.
NASA Astrophysics Data System (ADS)
McCarty, J.; Clark, A. J.; Copperman, J.; Guenza, M. G.
2014-05-01
Structural and thermodynamic consistency of coarse-graining models across multiple length scales is essential for the predictive role of multi-scale modeling and molecular dynamic simulations that use mesoscale descriptions. Our approach is a coarse-grained model based on integral equation theory, which can represent polymer chains at variable levels of chemical details. The model is analytical and depends on molecular and thermodynamic parameters of the system under study, as well as on the direct correlation function in the k → 0 limit, c0. A numerical solution to the PRISM integral equations is used to determine c0, by adjusting the value of the effective hard sphere diameter, dHS, to agree with the predicted equation of state. This single quantity parameterizes the coarse-grained potential, which is used to perform mesoscale simulations that are directly compared with atomistic-level simulations of the same system. We test our coarse-graining formalism by comparing structural correlations, isothermal compressibility, equation of state, Helmholtz and Gibbs free energies, and potential energy and entropy using both united atom and coarse-grained descriptions. We find quantitative agreement between the analytical formalism for the thermodynamic properties, and the results of Molecular Dynamics simulations, independent of the chosen level of representation. In the mesoscale description, the potential energy of the soft-particle interaction becomes a free energy in the coarse-grained coordinates which preserves the excess free energy from an ideal gas across all levels of description. The structural consistency between the united-atom and mesoscale descriptions means the relative entropy between descriptions has been minimized without any variational optimization parameters. The approach is general and applicable to any polymeric system in different thermodynamic conditions.
McCarty, J.; Clark, A. J.; Copperman, J.; Guenza, M. G.
2014-05-28
Structural and thermodynamic consistency of coarse-graining models across multiple length scales is essential for the predictive role of multi-scale modeling and molecular dynamic simulations that use mesoscale descriptions. Our approach is a coarse-grained model based on integral equation theory, which can represent polymer chains at variable levels of chemical details. The model is analytical and depends on molecular and thermodynamic parameters of the system under study, as well as on the direct correlation function in the k → 0 limit, c{sub 0}. A numerical solution to the PRISM integral equations is used to determine c{sub 0}, by adjusting the value of the effective hard sphere diameter, d{sub HS}, to agree with the predicted equation of state. This single quantity parameterizes the coarse-grained potential, which is used to perform mesoscale simulations that are directly compared with atomistic-level simulations of the same system. We test our coarse-graining formalism by comparing structural correlations, isothermal compressibility, equation of state, Helmholtz and Gibbs free energies, and potential energy and entropy using both united atom and coarse-grained descriptions. We find quantitative agreement between the analytical formalism for the thermodynamic properties, and the results of Molecular Dynamics simulations, independent of the chosen level of representation. In the mesoscale description, the potential energy of the soft-particle interaction becomes a free energy in the coarse-grained coordinates which preserves the excess free energy from an ideal gas across all levels of description. The structural consistency between the united-atom and mesoscale descriptions means the relative entropy between descriptions has been minimized without any variational optimization parameters. The approach is general and applicable to any polymeric system in different thermodynamic conditions.
NASA Astrophysics Data System (ADS)
Lumentut, Mikail F.; Howard, Ian M.
2016-02-01
This paper focuses on the primary development of novel numerical and analytical techniques of the modal damped vibration energy harvesters with arbitrary proof mass offset. The key equations of electromechanical finite element discretisation using the extended Lagrangian principle are revealed and simplified to give matrix and scalar forms of the coupled system equations, indicating the most relevant numerical technique for the power harvester research. To evaluate the performance of the numerical study, the analytical closed-form boundary value equations have been developed using the extended Hamiltonian principle. The results from the electromechanical frequency response functions (EFRFs) derived from two theoretical studies show excellent agreement with experimental studies. The benefit of the numerical technique is in providing effective and quick predictions for analysing parametric designs and physical properties of piezoelectric materials. Although analytical technique provides a challenging process for analysing the complex smart structure, it shows complementary study for validating the numerical technique.
Analytical support for a new, low-level radioactive wastewater treatment plant
Jones, V.D.; Marsh, J.H.; Ingram, L.M.; Melton, W.L.; Magonigal, E.J.
1990-01-01
The Savannah River Site (SRS) located in Aiken, SC, is operated by Westinghouse Savannah River Company under contract with the US Department of Energy. The mission of SRS is to manufacture radioisotopes for use in national defense and space exploration. The F/H Effluent Treatment Facility (ETF) is a wastewater treatment plant supporting SRS for low-level radioactive process waste streams. In order to comply with the Federal Resource Conservation and Recovery Act, the facility had to become operational by November 8, 1988. The F/H ETF employs pH adjustment, microfiltration, organic removal, reverse osmosis, evaporation, and ion exchange to remove contaminants prior to discharge to the environment via a state-permitted outfall. Concentrated contaminants removed by these processes are diverted to other facilities for further processing. The ETF is supported by a 24 hr/day facility laboratory for process control and characterization of influent feed, treated effluent water, and concentrated waste. Permit compliance analyses reported to the state of SC are performed by an offsite certified contract laboratory. The support laboratory is efficiently organized to provide: metal analyses by ICP-AES, alpha/beta/gamma activity counting, process ions by Ion Selective Electrode (ISE), oil and grease analyses by IR technique, mercury via cold vapor AA, conductivity, turbidity, and pH. All instrumentation is contained in hoods for radioactive sample handling.
Study of the crossing of quasi-energy levels in a four-level system
Arushanyan, S; Melikyan, A; Saakyan, S
2011-05-31
It was shown previously that in taking into account only dipole transitions, the crossing of quasi-energy levels is possible in the system if any of the transitions forms a closed loop. It followed herefrom that for the analysis of the crossing conditions, it is necessary to consider a system which has at least four levels. In this paper we show that we can uniquely specify which quasi-energy levels cross at the given values of the parameters of the atomic system and radiation field, without solving an algebraic quartic equation. It was found that the most suitable system for the implementation of the crossing is the group of energy levels {sup 5}S{sub 1/2}, {sup 5}P{sub 1/2}, {sup 5}P{sub 3/2} and {sup 5}D{sub 3/2} of a rubidium atom. The performed calculations of the laser field intensity and frequency values at which crossing takes place in this system show that they are easily attainable. It turned out that in this system there occur crossing of quasi-energy levels corresponding to the excited atomic levels. (intersection of quasi-energy levels)
NASA Astrophysics Data System (ADS)
Donahue, William; Newhauser, Wayne D.; Ziegler, James F.
2016-09-01
Many different approaches exist to calculate stopping power and range of protons and heavy charged particles. These methods may be broadly categorized as physically complete theories (widely applicable and complex) or semi-empirical approaches (narrowly applicable and simple). However, little attention has been paid in the literature to approaches that are both widely applicable and simple. We developed simple analytical models of stopping power and range for ions of hydrogen, carbon, iron, and uranium that spanned intervals of ion energy from 351 keV u-1 to 450 MeV u-1 or wider. The analytical models typically reproduced the best-available evaluated stopping powers within 1% and ranges within 0.1 mm. The computational speed of the analytical stopping power model was 28% faster than a full-theoretical approach. The calculation of range using the analytic range model was 945 times faster than a widely-used numerical integration technique. The results of this study revealed that the new, simple analytical models are accurate, fast, and broadly applicable. The new models require just 6 parameters to calculate stopping power and range for a given ion and absorber. The proposed model may be useful as an alternative to traditional approaches, especially in applications that demand fast computation speed, small memory footprint, and simplicity.
Ough, E A; Lewis, B J; Andrews, W S; Bennett, L G I; Hancock, R G V; D'Agastino, P A
2006-05-01
An analytical exercise was initiated in order to determine those procedures with the capability to measure total uranium and uranium (238U/235U) isotopic ratios in urine samples containing >0.02 microg U kg-1 urine. A host laboratory prepared six identical sets of twelve synthetic urine samples containing total uranium in the range of 25 to 770 ng U kg-1 urine and with 238U/235U isotopic ratios ranging from 138 (100% NU) to 215 (51% DU). Sets of samples were shipped to five testing laboratories (four based in Canada and one based in Europe). Each laboratory utilized one of the following analytical techniques: sector field inductively coupled plasma mass spectrometry (ICP-SF-MS), quadrupole inductively coupled plasma mass spectrometry (ICP-Q-MS), thermal ionization mass spectrometry (TIMS), and instrumental/delayed neutron activation analysis (I/DNAA), in their analyses.
1988-09-01
5 Sample The samples taken from each population will not be random samples . They will be nonprobability , purposive samples . More specifically, they...section will justify why statistical techniques based on the assumption of a random sample , will be used. First, this is the only possible method of...w lu 88 12 21 029 AFIT/GSM/LSM/88S-22 DEVELOPING CRITERIA FOR SAMPLE SIZES IN JET ENGINE ANALYTICAL COMPONENT INSPECTIONS AND THE ASSOCIATED
Degeneracy of energy levels of pseudo-Gaussian oscillators
Iacob, Theodor-Felix; Iacob, Felix; Lute, Marina
2015-12-07
We study the main features of the isotropic radial pseudo-Gaussian oscillators spectral properties. This study is made upon the energy levels degeneracy with respect to orbital angular momentum quantum number. In a previous work [6] we have shown that the pseudo-Gaussian oscillators belong to the class of quasi-exactly solvable models and an exact solution has been found.
Levelized cost of energy for a Backward Bent Duct Buoy
Bull, Diana; Jenne, D. Scott; Smith, Christopher S.; ...
2016-07-18
The Reference Model Project, supported by the U.S. Department of Energy, was developed to provide publicly available technical and economic benchmarks for a variety of marine energy converters. The methodology to achieve these benchmarks is to develop public domain designs that incorporate power performance estimates, structural models, anchor and mooring designs, power conversion chain designs, and estimates of the operations and maintenance, installation, and environmental permitting required. The reference model designs are intended to be conservative, robust, and experimentally verified. The Backward Bent Duct Buoy (BBDB) presented in this paper is one of three wave energy conversion devices studied withinmore » the Reference Model Project. Furthermore, comprehensive modeling of the BBDB in a Northern California climate has enabled a full levelized cost of energy (LCOE) analysis to be completed on this device.« less
Levelized cost of energy for a Backward Bent Duct Buoy
Bull, Diana; Jenne, D. Scott; Smith, Christopher S.; Copping, Andrea E.; Copeland, Guild
2016-12-01
The Reference Model Project, supported by the U.S. Department of Energy, was developed to provide publically available technical and economic benchmarks for a variety of marine energy converters. The methodology to achieve these benchmarks is to develop public domain designs that incorporate power performance estimates, structural models, anchor and mooring designs, power conversion chain designs, and estimates of the operations and maintenance, installation, and environmental permitting required. The reference model designs are intended to be conservative, robust, and experimentally verified. The Backward Bent Duct Buoy (BBDB) presented in this paper is one of three wave energy conversion devices studied within the Reference Model Project. Comprehensive modeling of the BBDB in a Northern California climate has enabled a full levelized cost of energy (LCOE) analysis to be completed on this device.
Levelized cost of energy for a Backward Bent Duct Buoy
Bull, Diana; Jenne, D. Scott; Smith, Christopher S.; Copping, Andrea E.; Copeland, Guild
2016-07-18
The Reference Model Project, supported by the U.S. Department of Energy, was developed to provide publicly available technical and economic benchmarks for a variety of marine energy converters. The methodology to achieve these benchmarks is to develop public domain designs that incorporate power performance estimates, structural models, anchor and mooring designs, power conversion chain designs, and estimates of the operations and maintenance, installation, and environmental permitting required. The reference model designs are intended to be conservative, robust, and experimentally verified. The Backward Bent Duct Buoy (BBDB) presented in this paper is one of three wave energy conversion devices studied within the Reference Model Project. Furthermore, comprehensive modeling of the BBDB in a Northern California climate has enabled a full levelized cost of energy (LCOE) analysis to be completed on this device.
Levelized cost of energy for a Backward Bent Duct Buoy
Bull, Diana; Jenne, D. Scott; Smith, Christopher S.; Copping, Andrea E.; Copeland, Guild
2016-07-18
The Reference Model Project, supported by the U.S. Department of Energy, was developed to provide publicly available technical and economic benchmarks for a variety of marine energy converters. The methodology to achieve these benchmarks is to develop public domain designs that incorporate power performance estimates, structural models, anchor and mooring designs, power conversion chain designs, and estimates of the operations and maintenance, installation, and environmental permitting required. The reference model designs are intended to be conservative, robust, and experimentally verified. The Backward Bent Duct Buoy (BBDB) presented in this paper is one of three wave energy conversion devices studied within the Reference Model Project. Furthermore, comprehensive modeling of the BBDB in a Northern California climate has enabled a full levelized cost of energy (LCOE) analysis to be completed on this device.
Energy balance regulation by thyroid hormones at central level.
López, Miguel; Alvarez, Clara V; Nogueiras, Rubén; Diéguez, Carlos
2013-07-01
Classically, medical textbooks taught that most effects of thyroid hormones (THs) on energy homeostasis are directly exerted in peripheral tissues. However, current evidence is changing (and challenging) our perspective about the role of THs from a 'peripheral' to a 'central' vision, implying that they affect food intake, energy expenditure, and metabolism by acting, to a large extent, at the central level. Interestingly, effects of THs are interrelated with global energy sensors in the central nervous system (CNS), such as uncoupling protein 2 (UCP2), AMP-activated protein kinase (AMPK; the 'AMPK-BAT axis'), and mechanistic target of rapamycin (mTOR). Here, we review what is currently known about THs and their regulation of energy balance and metabolism in both peripheral and central tissues.
Energy levels of double triangular graphene quantum dots
Liang, F. X.; Jiang, Z. T. Zhang, H. Y.; Li, S.; Lv, Z. T.
2014-09-28
We investigate theoretically the energy levels of the coupled double triangular graphene quantum dots (GQDs) based on the tight-binding Hamiltonian model. The double GQDs including the ZZ-type, ZA-type, and AA-type GQDs with the two GQDs having the zigzag or armchair boundaries can be coupled together via different interdot connections, such as the direct coupling, the chains of benzene rings, and those of carbon atoms. It is shown that the energy spectrum of the coupled double GQDs is the amalgamation of those spectra of the corresponding two isolated GQDs with the modification triggered by the interdot connections. The interdot connection is inclined to lift up the degeneracies of the energy levels in different degree, and as the connection changes from the direct coupling to the long chains, the removal of energy degeneracies is suppressed in ZZ-type and AA-type double GQDs, which indicates that the two coupled GQDs are inclined to become decoupled. Then we consider the influences on the spectra of the coupled double GQDs induced by the electric fields applied on the GQDs or the connection, which manifests as the global spectrum redistribution or the local energy level shift. Finally, we study the symmetrical and asymmetrical energy spectra of the double GQDs caused by the substrates supporting the two GQDs, clearly demonstrating how the substrates affect the double GQDs' spectrum. This research elucidates the energy spectra of the coupled double GQDs, as well as the mechanics of manipulating them by the electric field and the substrates, which would be a significant reference for designing GQD-based devices.
González-Lavado, Eloisa; Corchado, Jose C.; Espinosa-Garcia, Joaquin
2014-02-14
Based exclusively on high-level ab initio calculations, a new full-dimensional analytical potential energy surface (PES-2014) for the gas-phase reaction of hydrogen abstraction from methane by an oxygen atom is developed. The ab initio information employed in the fit includes properties (equilibrium geometries, relative energies, and vibrational frequencies) of the reactants, products, saddle point, points on the reaction path, and points on the reaction swath, taking especial caution respecting the location and characterization of the intermediate complexes in the entrance and exit channels. By comparing with the reference results we show that the resulting PES-2014 reproduces reasonably well the whole set of ab initio data used in the fitting, obtained at the CCSD(T) = FULL/aug-cc-pVQZ//CCSD(T) = FC/cc-pVTZ single point level, which represents a severe test of the new surface. As a first application, on this analytical surface we perform an extensive dynamics study using quasi-classical trajectory calculations, comparing the results with recent experimental and theoretical data. The excitation function increases with energy (concave-up) reproducing experimental and theoretical information, although our values are somewhat larger. The OH rotovibrational distribution is cold in agreement with experiment. Finally, our results reproduce experimental backward scattering distribution, associated to a rebound mechanism. These results lend confidence to the accuracy of the new surface, which substantially improves the results obtained with our previous surface (PES-2000) for the same system.
Self-energy shift of the energy levels of atomic hydrogen in photonic crystal medium
NASA Astrophysics Data System (ADS)
Gainutdinov, R. Kh; Khamadeev, M. A.; Steryakov, O. V.; Ziyatdinova, K. A.; Salakhov, M. Kh
2016-05-01
Corrections to the average kinetic energy of atomic electrons caused by the change in electron mass in the photonic crystal medium are investigated. Corresponding shift of energy levels of atoms placed in a photonic crystal is shown to be of order of the ordinary Lamb shift.
NASA Technical Reports Server (NTRS)
Ivanenko, I. P.; Kanevsky, B. L.; Roganova, T. M.; Sizov, V. V.; Triphonova, S. V.
1985-01-01
Analytical and numerical methods of calculation of the energy and three dimensional EPS characteristics are reported. The angular and lateral functions of electrons in EPS have been obtained by the Landau and small angle approximations A and B and compared with earlier data. A numerical method of solution of cascade equations for the EPS distribution function moments has been constructed. Considering the equilibrium rms angle as an example, errors appearing when approximating the elementary process cross sections by their asymptotic expressions are analyzed.
Mo uc(v) Energy Levels and f values
NASA Astrophysics Data System (ADS)
Pan, Lin; Beck, Donald R.
2004-05-01
Relativistic Configuration Interaction (RCI) calculations have been done for the lowest 12 J=0 even parity levels, and the lowest 30 J=1 odd parity levels of Mo uc(v.) For the J=0 4d^2 and 4d 5d energy differences, the average error is 229 cm-1 ( M. I. Cabeza, F. G. Meijer, and L. Iglesias, Phys. Scr. 34), 223 (1986). For the other J=0 levels, the average difference with experiment (A. Tauheed, M. S. Z. Chaghtai, and K. Rahimullah, Phys. Scr. 31), 369 (1985) is considerably greater. Our average energy errors for the 11 known ^2 J=1 levels is 233 cm-1, excluding the 5s 5p ^1 P level, which is 1580 cm-1 higher than observed ^2. We predict positions of 19 4p^5 4d^3 levels, as well as f values for the 360 transitions between the calculated levels. Gauge agreements are good for transitions with f > .01. Details of the methodology have been published elsewhere (D. R. Beck and L. Pan, Phys. Scr. 69), 91 (2004).
Alignment of electronic energy levels at electrochemical interfaces.
Cheng, Jun; Sprik, Michiel
2012-08-28
The position of electronic energy levels in a phase depends on the surface potentials at its boundaries. Bringing two phases in contact at an interface will alter the surface potentials shifting the energy levels relative to each other. Calculating such shifts for electrochemical interfaces requires a combination of methods from computational surface science and physical chemistry. The problem is closely related to the computation of potentials of electrochemically inactive electrodes. These so-called ideally polarizable interfaces are impossible to cross for electrons. In this perspective we review two density functional theory based methods that have been developed for this purpose, the workfunction method and the hydrogen insertion method. The key expressions of the two methods are derived from the formal theory of absolute electrode potentials. As an illustration of the workfunction method we review the computation of the potential of zero charge of the Pt(111)-water interface as recently published by a number of groups. The example of the hydrogen insertion method is from our own work on the rutile TiO(2)(110)-water interface at the point of zero proton charge. The calculations are summarized in level diagrams aligning the electronic energy levels of the solid electrode (Fermi level of the metal, valence band maximum and conduction band minimum of the semiconductor) to the band edges of liquid water and the standard potential for the reduction of the hydroxyl radical. All potentials are calculated at the same level of density functional theory using the standard hydrogen electrode as common energy reference. Comparison to experiment identifies the treatment of the valence band of water as a potentially dangerous source of error for application to electrocatalysis and photocatalysis.
Chiba, Mahito; Tsuneda, Takao; Hirao, Kimihiko
2006-04-14
An analytical excitation energy gradient of long-range corrected time-dependent density functional theory (LC-TDDFT) is presented. This is based on a previous analytical TDDFT gradient formalism, which avoids solving the coupled-perturbed Kohn-Sham equation for each nuclear degree of freedom. In LC-TDDFT, exchange interactions are evaluated by combining the short-range part of a DFT exchange functional with the long-range part of the Hartree-Fock exchange integral. This LC-TDDFT gradient was first examined by calculating the excited state geometries and adiabatic excitation energies of small typical molecules and a small protonated Schiff base. As a result, we found that long-range interactions play a significant role even in valence excited states of small systems. This analytical LC-TDDFT gradient was also applied to the investigations of small twisted intramolecular charge transfer (TICT) systems. By comparing with calculated ab initio multireference perturbation theory and experimental results, we found that LC-TDDFT gave much more accurate absorption and fluorescence energies of these systems than those of conventional TDDFTs using pure and hybrid functionals. For optimized excited state geometries, LC-TDDFT provided fairly different twisting and wagging angles of these small TICT systems in comparison with conventional TDDFT results.
NASA Astrophysics Data System (ADS)
Lambin, Ph.; Vigneron, J. P.
1984-03-01
The analytical tetrahedron method (ATM) for evaluating perfect-crystal Green's functions is reviewed. It is shown that the ATM allows for computing matrix elements of the resolvent operator in the entire complex-energy plane. These elements are written as a scalar product involving weighting functions of the complex energy, which are computed on a mesh of k--> points in the Brillouin zone. When the usual approximations are made within each tetrahedron, namely linear interpolations for the dispersion relations as well as for the numerator matrix elements, the weighting functions only depend on the perfect-crystal dispersion relations. In addition, the analytical expression obtained for a tetrahedral contribution to the weighting functions is simpler than what is usually expected. Analytical properties of our expressions are discussed and all the limiting forms are worked out. Special attention is paid to the numerical stability of the algorithm producing the Green's-function imaginary part on the real energy axis. Expressions which have been published earlier are subject to computational problems, which are solved in the new formulas reported here.
Whitman, Daniel S; Caleo, Suzette; Carpenter, Nichelle C; Horner, Margaret T; Bernerth, Jeremy B
2012-07-01
This article uses meta-analytic methods (k = 38) to examine the relationship between organizational justice climate and unit-level effectiveness. Overall, our results suggest that the relationship between justice and effectiveness is significant (ρ = .40) when both constructs are construed at the collective level. Our results also indicate that distributive justice climate was most strongly linked with unit-level performance (e.g., productivity, customer satisfaction), whereas interactional justice was most strongly related to unit-level processes (e.g., organizational citizenship behavior, cohesion). We also show that a number of factors moderate this relationship, including justice climate strength, the level of referent in the justice measure, the hierarchical level of the unit, and how criteria are classified. We elaborate on these findings and attempt to provide a clearer direction for future research in this area.
Core level binding energies of functionalized and defective graphene
Kaukonen, Markus; Havu, Paula; Ljungberg, Mathias P; Ayala, Paola; Kauppinen, Esko I
2014-01-01
Summary X-ray photoelectron spectroscopy (XPS) is a widely used tool for studying the chemical composition of materials and it is a standard technique in surface science and technology. XPS is particularly useful for characterizing nanostructures such as carbon nanomaterials due to their reduced dimensionality. In order to assign the measured binding energies to specific bonding environments, reference energy values need to be known. Experimental measurements of the core level signals of the elements present in novel materials such as graphene have often been compared to values measured for molecules, or calculated for finite clusters. Here we have calculated core level binding energies for variously functionalized or defected graphene by delta Kohn–Sham total energy differences in the real-space grid-based projector-augmented wave density functional theory code (GPAW). To accurately model extended systems, we applied periodic boundary conditions in large unit cells to avoid computational artifacts. In select cases, we compared the results to all-electron calculations using an ab initio molecular simulations (FHI-aims) code. We calculated the carbon and oxygen 1s core level binding energies for oxygen and hydrogen functionalities such as graphane-like hydrogenation, and epoxide, hydroxide and carboxylic functional groups. In all cases, we considered binding energy contributions arising from carbon atoms up to the third nearest neighbor from the functional group, and plotted C 1s line shapes by using experimentally realistic broadenings. Furthermore, we simulated the simplest atomic defects, namely single and double vacancies and the Stone–Thrower–Wales defect. Finally, we studied modifications of a reactive single vacancy with O and H functionalities, and compared the calculated values to data found in the literature. PMID:24605278
Neng, N R; Silva, A R M; Nogueira, J M F
2010-11-19
A novel enrichment technique, adsorptive μ-extraction (AμE), is proposed for trace analysis of polar solutes in aqueous media. The preparation, stability tests and development of the analytical devices using two geometrical configurations, i.e. bar adsorptive μ-extraction (BAμE) and multi-spheres adsorptive μ-extraction (MSAμE) is fully discussed. From the several sorbent materials tested, activated carbons and polystyrene divinylbenzene phases demonstrated the best stability, robustness and to be the most suitable for analytical purposes. The application of both BAμE and MSAμE devices proved remarkable performance for the determination of trace levels of polar solutes and metabolites (e.g. pesticides, disinfection by-products, drugs of abuse and pharmaceuticals) in water matrices and biological fluids. By comparing AμE techniques with stir bar sorptive extraction based on polydimethylsiloxane phase, great effectiveness is attained overcoming the limitations of the latter enrichment approach regarding the more polar solutes. Furthermore, convenient sensitivity and selectivity is reached through AμE techniques, since the great advantage of this new analytical technology is the possibility to choose the most suitable sorbent to each particular type of application. The enrichment techniques proposed are cost-effective, easy to prepare and work-up, demonstrating robustness and to be a remarkable analytical tool for trace analysis of priority solutes in areas of recognized importance such as environment, forensic and other related life sciences.
Framework for State-Level Renewable Energy Market Potential Studies
Kreycik, C.; Vimmerstedt, L.; Doris, E.
2010-01-01
State-level policymakers are relying on estimates of the market potential for renewable energy resources as they set goals and develop policies to accelerate the development of these resources. Therefore, accuracy of such estimates should be understood and possibly improved to appropriately support these decisions. This document provides a framework and next steps for state officials who require estimates of renewable energy market potential. The report gives insight into how to conduct a market potential study, including what supporting data are needed and what types of assumptions need to be made. The report distinguishes between goal-oriented studies and other types of studies, and explains the benefits of each.
NASA Astrophysics Data System (ADS)
Wang, Linwang
2014-03-01
Accurate calculation of defect level energies in semiconductors and their carrier capturing rate is an important issue in ab initio prediction of semiconductor properties. In this talk, I will present our result work in ab initio shallow level calculation and deep level caused nonradiative recombination rate calculation. In the shallow acceptor level calculation, a large system up to 64,000 atoms needs to be used to properly describe the weakly bounded hole wave functions. The single particle Hamiltonian of that system is patched from bulk potential and central potential. Furthermore, GW calculation is used to correct the one site potential of the impurity atom. The resulting binding energy agrees excellently with the experiments within 10 meV. To calculate the nonradiative decay rate, the electron-phonon coupling constants in the defect system are calculated all at once using a new variational algorithm. Multiphonon process formalism is used to calculate the nonradiative decay rate. It is found that the transition is induced by the electron and the optical phonon coupling, but the energy conservation is mostly satisfied by the acoustic phonons. The new algorithm allows fast calculation of such nonradiative decay rate for any defect levels, as well as other multiphonon processes in nanostructures. This work was supported by the Director, Office of Science (SC), Basic Energy Science (BES)/Materials Science and Engineering Division (MSED) of the U.S. Department of Energy (DOE) under the contract No. DE-AC02-05CH11231.
Quinn, John J.; Greer, Christopher B.; Carr, Adrianne E.
2014-10-01
The purpose of this study is to update a one-dimensional analytical groundwater flow model to examine the influence of potential groundwater withdrawal in support of utility-scale solar energy development at the Afton Solar Energy Zone (SEZ) as a part of the Bureau of Land Management’s (BLM’s) Solar Energy Program. This report describes the modeling for assessing the drawdown associated with SEZ groundwater pumping rates for a 20-year duration considering three categories of water demand (high, medium, and low) based on technology-specific considerations. The 2012 modeling effort published in the Final Programmatic Environmental Impact Statement for Solar Energy Development in Six Southwestern States (Solar PEIS; BLM and DOE 2012) has been refined based on additional information described below in an expanded hydrogeologic discussion.
Public budgets for energy RD&D and the effects on energy intensity and pollution levels.
Balsalobre, Daniel; Álvarez, Agustín; Cantos, José María
2015-04-01
This study, based on the N-shaped cubic model of the environmental Kuznets curve, analyzes the evolution of per capita greenhouse gas emissions (GHGpc) using not just economic growth but also public budgets dedicated to energy-oriented research development and demonstration (RD&D) and energy intensity. The empirical evidence, obtained from an econometric model of fixed effects for 28 OECD countries during 1994-2010, suggests that energy innovations help reduce GHGpc levels and mitigate the negative impact of energy intensity on environmental quality. When countries develop active energy RD&D policies, they can reduce both the rates of energy intensity and the level of GHGpc emissions. This paper incorporates a moderating variable to the econometric model that emphasizes the effect that GDP has on energy intensity. It also adds a variable that reflects the difference between countries that have made a greater economic effort in energy RD&D, which in turn corrects the GHG emissions resulting from the energy intensity of each country.
Sleep and brain energy levels: ATP changes during sleep.
Dworak, Markus; McCarley, Robert W; Kim, Tae; Kalinchuk, Anna V; Basheer, Radhika
2010-06-30
Sleep is one of the most pervasive biological phenomena, but one whose function remains elusive. Although many theories of function, indirect evidence, and even common sense suggest sleep is needed for an increase in brain energy, brain energy levels have not been directly measured with modern technology. We here report that ATP levels, the energy currency of brain cells, show a surge in the initial hours of spontaneous sleep in wake-active but not in sleep-active brain regions of rat. The surge is dependent on sleep but not time of day, since preventing sleep by gentle handling of rats for 3 or 6 h also prevents the surge in ATP. A significant positive correlation was observed between the surge in ATP and EEG non-rapid eye movement delta activity (0.5-4.5 Hz) during spontaneous sleep. Inducing sleep and delta activity by adenosine infusion into basal forebrain during the normally active dark period also increases ATP. Together, these observations suggest that the surge in ATP occurs when the neuronal activity is reduced, as occurs during sleep. The levels of phosphorylated AMP-activated protein kinase (P-AMPK), well known for its role in cellular energy sensing and regulation, and ATP show reciprocal changes. P-AMPK levels are lower during the sleep-induced ATP surge than during wake or sleep deprivation. Together, these results suggest that sleep-induced surge in ATP and the decrease in P-AMPK levels set the stage for increased anabolic processes during sleep and provide insight into the molecular events leading to the restorative biosynthetic processes occurring during sleep.
NASA Technical Reports Server (NTRS)
Goldstein, J. I.; Williams, D. B.
1992-01-01
This paper reviews and discusses future directions in analytical electron microscopy for microchemical analysis using X-ray and Electron Energy Loss Spectroscopy (EELS). The technique of X-ray microanalysis, using the ratio method and k(sub AB) factors, is outlined. The X-ray absorption correction is the major barrier to the objective of obtaining I% accuracy and precision in analysis. Spatial resolution and Minimum Detectability Limits (MDL) are considered with present limitations of spatial resolution in the 2 to 3 microns range and of MDL in the 0.1 to 0.2 wt. % range when a Field Emission Gun (FEG) system is used. Future directions of X-ray analysis include improvement in X-ray spatial resolution to the I to 2 microns range and MDL as low as 0.01 wt. %. With these improvements the detection of single atoms in the analysis volume will be possible. Other future improvements include the use of clean room techniques for thin specimen preparation, quantification available at the I% accuracy and precision level with light element analysis quantification available at better than the 10% accuracy and precision level, the incorporation of a compact wavelength dispersive spectrometer to improve X-ray spectral resolution, light element analysis and MDL, and instrument improvements including source stability, on-line probe current measurements, stage stability, and computerized stage control. The paper reviews the EELS technique, recognizing that it has been slow to develop and still remains firmly in research laboratories rather than in applications laboratories. Consideration of microanalysis with core-loss edges is given along with a discussion of the limitations such as specimen thickness. Spatial resolution and MDL are considered, recognizing that single atom detection is already possible. Plasmon loss analysis is discussed as well as fine structure analysis. New techniques for energy-loss imaging are also summarized. Future directions in the EELS technique will be
NASA Technical Reports Server (NTRS)
Goldstein, J. I.; Williams, D. B.
1992-01-01
This paper reviews and discusses future directions in analytical electron microscopy for microchemical analysis using X-ray and Electron Energy Loss Spectroscopy (EELS). The technique of X-ray microanalysis, using the ratio method and k(sub AB) factors, is outlined. The X-ray absorption correction is the major barrier to the objective of obtaining I% accuracy and precision in analysis. Spatial resolution and Minimum Detectability Limits (MDL) are considered with present limitations of spatial resolution in the 2 to 3 microns range and of MDL in the 0.1 to 0.2 wt. % range when a Field Emission Gun (FEG) system is used. Future directions of X-ray analysis include improvement in X-ray spatial resolution to the I to 2 microns range and MDL as low as 0.01 wt. %. With these improvements the detection of single atoms in the analysis volume will be possible. Other future improvements include the use of clean room techniques for thin specimen preparation, quantification available at the I% accuracy and precision level with light element analysis quantification available at better than the 10% accuracy and precision level, the incorporation of a compact wavelength dispersive spectrometer to improve X-ray spectral resolution, light element analysis and MDL, and instrument improvements including source stability, on-line probe current measurements, stage stability, and computerized stage control. The paper reviews the EELS technique, recognizing that it has been slow to develop and still remains firmly in research laboratories rather than in applications laboratories. Consideration of microanalysis with core-loss edges is given along with a discussion of the limitations such as specimen thickness. Spatial resolution and MDL are considered, recognizing that single atom detection is already possible. Plasmon loss analysis is discussed as well as fine structure analysis. New techniques for energy-loss imaging are also summarized. Future directions in the EELS technique will be
Thirty-seventh ORNL/DOE conference on analytical chemistry in energy technology: Abstracts of papers
1997-12-31
Abstracts only are given for papers presented during the following topical sessions: Opportunities for collaboration: Industry, academic, national laboratories; Developments in sensor technology; Analysis in containment facilities; Improving the quality of environmental data; Process analysis; Field analysis; Radiological separations; Interactive analytical seminars; Measurements and chemical industry initiatives; and Isotopic measurements and mass spectroscopy.
Twenty-ninth ORNL/DOE conference on analytical chemistry in energy technology. Abstracts of papers
Not Available
1986-01-01
This booklet contains separate abstracts of 55 individual papers presented at this conference. Different sections in the book are titled as follows: laser techniques; resonance ionization spectroscopy; laser applications; new developments in mass spectrometry; analytical chemistry of hazardous waste; and automation and data management. (PLG)
Cheng, Hui G; Alshaarawy, Omayma; Cantave, Marven D; Anthony, James C
2016-10-01
Exposures to antioxidants (AO) are associated with levels of C-reactive protein (CRP), but the pattern of evidence is mixed, due in part to studying each potential AO, one at a time, when multiple AO exposures might affect CRP levels. By studying multiple AO via a composite indicator approach, we estimate the degree to which serum CRP level is associated with serum AO level. Standardised field survey protocols for the US National Health and Nutrition Examination Survey (NHANES) 2003-2006 yielded nationally representative cross-sectional samples of adults aged 20 years and older (n 8841). NHANES latex-enhanced nephelometry quantified serum CRP levels. Liquid chromatography quantified serum concentrations of vitamins A, E and C and carotenoids. Using structural equations, we regressed CRP level on AO levels, and derived a summary estimate for a composite of these potential antioxidants (CPA), with covariates held constant. The association linking CPA with CRP was inverse, stronger for slightly elevated CRP (1·8≤CRP<10 mg/l; slope= -1·08; 95 % CI -1·39, -0·77) and weaker for highly elevated CRP (≥10 mg/l; slope= -0·52; 95 % CI -0·68, -0·35), with little change when covariates were added. Vitamins A and C, as well as lutein+zeaxanthin, were prominent contributors to the composite. In these cross-sectional data studied via a composite indicator approach, the CPA level and the CRP level were inversely related. The stage is set for more confirmatory longitudinal or intervention research on multiple vitamins. The composite indicator approach might be most useful in epidemiology when several exposure constructs are too weakly inter-correlated to be studied via formal measurement models for underlying latent dimensions.
Department of Energy low-level radioactive waste disposal concepts
Ozaki, C.; Page, L.; Morreale, B.; Owens, C.
1990-01-01
The Department of Energy (DOE) manages its low-level waste (LLW), regulated by DOE Order 5820.2A by using an overall systems approach. This systems approach provides an improved and consistent management system for all DOE LLW waste, from generation to disposal. This paper outlines six basic disposal concepts used in the systems approach, discusses issues associated with each of the concepts, and outlines both present and future disposal concepts used at six DOE sites. 3 refs., 9 figs.
Marcelletti, John F; Evans, Cindy L; Saxena, Manju; Lopez, Adriana E
2015-07-01
It is often necessary to adjust for detectable endogenous biomarker levels in spiked validation samples (VS) and in selectivity determinations during bioanalytical method validation for ligand-binding assays (LBA) with a matrix like normal human serum (NHS). Described herein are case studies of biomarker analyses using multiplex LBA which highlight the challenges associated with such adjustments when calculating percent analytical recovery (%AR). The LBA test methods were the Meso Scale Discovery V-PLEX® proinflammatory and cytokine panels with NHS as test matrix. The NHS matrix blank exhibited varied endogenous content of the 20 individual cytokines before spiking, ranging from undetectable to readily quantifiable. Addition and subtraction methods for adjusting endogenous cytokine levels in %AR calculations are both used in the bioanalytical field. The two methods were compared in %AR calculations following spiking and analysis of VS for cytokines having detectable endogenous levels in NHS. Calculations for %AR obtained by subtracting quantifiable endogenous biomarker concentrations from the respective total analytical VS values yielded reproducible and credible conclusions. The addition method, in contrast, yielded %AR conclusions that were frequently unreliable and discordant with values obtained with the subtraction adjustment method. It is shown that subtraction of assay signal attributable to matrix is a feasible alternative when endogenous biomarkers levels are below the limit of quantitation, but above the limit of detection. These analyses confirm that the subtraction method is preferable over that using addition to adjust for detectable endogenous biomarker levels when calculating %AR for biomarker LBA.
Education: a microfluidic platform for university-level analytical chemistry laboratories.
Greener, Jesse; Tumarkin, Ethan; Debono, Michael; Dicks, Andrew P; Kumacheva, Eugenia
2012-02-21
We demonstrate continuous flow acid-base titration reactions as an educational microfluidic platform for undergraduate and graduate analytical chemistry courses. A series of equations were developed for controlling and predicting the results of acid-base neutralisation reactions conducted in a microfluidic format, including the combinations of (i) a strong base and a strong acid, (ii) a strong base and a weak acid, and (iii) a strong base and a multiprotic acid. Microfluidic titrations yielded excellent repeatability. The small experimental footprint is advantageous in crowded teaching laboratories, and it offers limited waste and exposure to potentially hazardous acids and bases. This platform will help promote the utilisation of microfluidics at an earlier stage of students' careers.
Energy levels scheme simulation of divalent cobalt doped bismuth germanate
Andreici, Emiliana-Laura; Petkova, Petya; Avram, Nicolae M.
2015-12-07
The aim of this paper is to simulate the energy levels scheme for Bismuth Germanate (BGO) doped with divalent cobalt, in order to give a reliable explanation for spectral experimental data. In the semiempirical crystal field theory we first modeled the Crystal Field Parameters (CFPs) of BGO:Cr{sup 2+} system, in the frame of Exchange Charge Model (ECM), with actually site symmetry of the impurity ions after doping. The values of CFPs depend on the geometry of doped host matrix and by parameter G of ECM. First, we optimized the geometry of undoped BGO host matrix and afterwards, that of doped BGO with divalent cobalt. The charges effect of ligands and covalence bonding between cobalt cations and oxygen anions, in the cluster approach, also were taken into account. With the obtained values of the CFPs we simulate the energy levels scheme of cobalt ions, by diagonalizing the matrix of the doped crystal Hamiltonian. Obviously, energy levels and estimated Racah parameters B and C were compared with the experimental spectroscopic data and discussed. Comparison of obtained results with experimental data shows quite satisfactory, which justify the model and simulation schemes used for the title system.
A Detailed Level Kinetics Model of NO Vibrational Energy Distributions
NASA Technical Reports Server (NTRS)
Sharma, Surendra P.; Gilmore, John; Cavolowsky, John A. (Technical Monitor)
1996-01-01
Several contemporary problems have pointed to the desirability of a detailed level kinetics approach to modeling the distribution of vibrational energy in NO. Such a model is necessary when vibrational redistribution reactions are insufficient to maintain a Boltzmann distribution over the vibrational energy states. Recent calculations of the rate constant for the first reaction of the Zeldovich mechanism (N2 + O (goes to) NO + N) have suggested that the product NO is formed in high vibrational states. In shock layer flowfields, the product NO molecules may experience an insufficient number of collisions to establish a Boltzmann distribution over vibrational states, thus necessitating a level kinetics model. In other flows, such as expansions of high temperature air, fast, near-resonance vibrational energy exchanges with N2 and O2 may also require a level specific model for NO because of the relative rates of vibrational exchange and redistribution. The proposed report will integrate computational and experimental components to construct such a model for the NO molecule.
A Detailed Level Kinetics Model of NO Vibrational Energy Distributions
NASA Technical Reports Server (NTRS)
Sharma, Surendra P.; Gilmore, John; Cavolowsky, John A. (Technical Monitor)
1996-01-01
Several contemporary problems have pointed to the desirability of a detailed level kinetics approach to modeling the distribution of vibrational energy in NO. Such a model is necessary when vibrational redistribution reactions are insufficient to maintain a Boltzmann distribution over the vibrational energy states. Recent calculations of the rate constant for the first reaction of the Zeldovich mechanism (N2 + O (goes to) NO + N) have suggested that the product NO is formed in high vibrational states. In shock layer flowfields, the product NO molecules may experience an insufficient number of collisions to establish a Boltzmann distribution over vibrational states, thus necessitating a level kinetics model. In other flows, such as expansions of high temperature air, fast, near-resonance vibrational energy exchanges with N2 and O2 may also require a level specific model for NO because of the relative rates of vibrational exchange and redistribution. The proposed report will integrate computational and experimental components to construct such a model for the NO molecule.
A full-dimensional analytical potential energy surface for the F+CH4→HF + CH3 reaction
NASA Astrophysics Data System (ADS)
Yang, Chuan-Lu; Wang, Mei-Shan; Liu, Wen-Wang; Zhang, Zhi-Hong; Ma, Xiao-Guang
2013-06-01
A full-dimensional analytical potential energy surface (APES) for the F + CH4 →HF + CH3 reaction is developed based on 7127 ab initio energy points at the unrestricted coupled-cluster with single, double, and perturbative triple excitations. The correlation-consistent polarized triple-split valence basis set is used. The APES is represented with a many-body expansion containing 239 parameters determined by the least square fitting method. The two-body terms of the APES are fitted by potential energy curves with multi-reference configuration interaction, which can describe the diatomic molecules (CH, H2, HF, and CF) accurately. It is found that the APES can reproduce the geometry and vibrational frequencies of the saddle point better than those available in the literature. The rate constants based on the present APES support the experimental results of Moore et al. [Int. J. Chem. Kin. 26, 813 (1994)]. The analytical first-order derivation of energy is also provided, making the present APES convenient and efficient for investigating the title reaction with quasiclassical trajectory calculations.
Gayley, K. G.; Mutel, R. L.; Jaeger, T. R.
2009-12-01
We derive analytic expressions and approximate them in closed form, for the effective detection aperture for Cerenkov radio emission from ultra-high-energy neutrinos striking the Moon. The resulting apertures are in good agreement with recent Monte Carlo simulations and support the conclusion of James and Protheroe that neutrino flux upper limits derived from the GLUE search were too low by an order of magnitude. We also use our analytic expressions to derive scaling laws for the aperture as a function of observational and lunar parameters. We find that at low frequencies downward-directed neutrinos always dominate, but at higher frequencies, the contribution from upward-directed neutrinos becomes increasingly important, especially at lower neutrino energies. Detecting neutrinos from Earth near the Greisen-Zatsepin-Kuz'min regime will likely require radio telescope arrays with extremely large collecting area (A{sub e} approx 10{sup 6} m{sup 2}) and hundreds of hours exposure time. Higher-energy neutrinos are most easily detected using lower frequencies. Lunar surface roughness is a decisive factor for obtaining detections at higher frequencies (nuapprox> 300 MHz) and higher energies (E approx> 10{sup 21} eV).
A rotamer energy level study of sulfuric acid
NASA Astrophysics Data System (ADS)
Partanen, Lauri; Pesonen, Janne; Sjöholm, Elina; Halonen, Lauri
2013-10-01
It is a common approach in quantum chemical calculations for polyatomic molecules to rigidly constrain some of the degrees of freedom in order to make the calculations computationally feasible. However, the presence of the rigid constraints also affects the kinetic energy operator resulting in the frozen mode correction, originally derived by Pesonen [J. Chem. Phys. 139, 144310 (2013)]. In this study, we compare the effects of this correction to several different approximations to the kinetic energy operator used in the literature, in the specific case of the rotamer energy levels of sulfuric acid. The two stable conformers of sulfuric acid are connected by the rotations of the O-S-O-H dihedral angles and possess C2 and Cs symmetry in the order of increasing energy. Our results show that of the models tested, the largest differences with the frozen mode corrected values were obtained by simply omitting the passive degrees of freedom. For the lowest 17 excited states, this inappropriate treatment introduces an increase of 9.6 cm-1 on average, with an increase of 8.7 cm-1 in the zero-point energies. With our two-dimensional potential energy surface calculated at the CCSD(T)-F12a/VDZ-F12 level, we observe a radical shift in the density of states compared to the harmonic picture, combined with an increase in zero point energy. Thus, we conclude that the quantum mechanical inclusion of the different conformers of sulfuric acid have a significant effect on its vibrational partition function, suggesting that it will also have an impact on the computational values of the thermodynamic properties of any reactions where sulfuric acid plays a role. Finally, we also considered the effect of the anharmonicities for the other vibrational degrees of freedom with a VSCF-calculation at the DF-MP2-F12/VTZ-F12 level of theory but found that the inclusion of the other conformer had the more important effect on the vibrational partition function.
A rotamer energy level study of sulfuric acid.
Partanen, Lauri; Pesonen, Janne; Sjöholm, Elina; Halonen, Lauri
2013-10-14
It is a common approach in quantum chemical calculations for polyatomic molecules to rigidly constrain some of the degrees of freedom in order to make the calculations computationally feasible. However, the presence of the rigid constraints also affects the kinetic energy operator resulting in the frozen mode correction, originally derived by Pesonen [J. Chem. Phys. 139, 144310 (2013)]. In this study, we compare the effects of this correction to several different approximations to the kinetic energy operator used in the literature, in the specific case of the rotamer energy levels of sulfuric acid. The two stable conformers of sulfuric acid are connected by the rotations of the O-S-O-H dihedral angles and possess C2 and Cs symmetry in the order of increasing energy. Our results show that of the models tested, the largest differences with the frozen mode corrected values were obtained by simply omitting the passive degrees of freedom. For the lowest 17 excited states, this inappropriate treatment introduces an increase of 9.6 cm(-1) on average, with an increase of 8.7 cm(-1) in the zero-point energies. With our two-dimensional potential energy surface calculated at the CCSD(T)-F12a/VDZ-F12 level, we observe a radical shift in the density of states compared to the harmonic picture, combined with an increase in zero point energy. Thus, we conclude that the quantum mechanical inclusion of the different conformers of sulfuric acid have a significant effect on its vibrational partition function, suggesting that it will also have an impact on the computational values of the thermodynamic properties of any reactions where sulfuric acid plays a role. Finally, we also considered the effect of the anharmonicities for the other vibrational degrees of freedom with a VSCF-calculation at the DF-MP2-F12/VTZ-F12 level of theory but found that the inclusion of the other conformer had the more important effect on the vibrational partition function.
An ab initio potential energy surface and vibrational energy levels of ZnH2.
Huang, Zheng Guo; Yu, Lei; Dai, Yu Mei
2010-04-15
A three-dimensional potential energy surface of the electronic ground state of ZnH(2) (X1 Sigma(g)+) molecule is constructed from more than 7500 ab initio points calculated at the internally contracted multireference configuration interaction with the Davidson correction (icMRCI+Q) level employing large basis sets. The calculated relative energies of various dissociation reactions are in good agreement with the previous theoretical/experimental values. Low-lying vibrational energy levels of ZnH(2), ZnD(2), and HZnD are calculated on the three-dimensional potential energy surface using the Lanczos algorithm, and found to be in good agreement with the available experimental band origins and the previous theoretical values. 2009 Wiley Periodicals, Inc.
Gallian, Sara Trieschmann, Jan; Mussenbrock, Thomas; Brinkmann, Ralf Peter; Hitchon, William N. G.
2015-01-14
This paper analyzes a situation which is common for magnetized technical plasmas such as dc magnetron discharges and high power impulse magnetron sputtering (HiPIMS) systems, where secondary electrons enter the plasma after being accelerated in the cathode fall and encounter a nearly uniform bulk. An analytic calculation of the distribution function of hot electrons is presented; these are described as an initially monoenergetic beam that slows down by Coulomb collisions with a Maxwellian distribution of bulk (cold) electrons, and by inelastic collisions with neutrals. Although this analytical solution is based on a steady-state assumption, a comparison of the characteristic time-scales suggests that it may be applicable to a variety of practical time-dependent discharges, and it may be used to introduce kinetic effects into models based on the hypothesis of Maxwellian electrons. The results are verified for parameters appropriate to HiPIMS discharges, by means of time-dependent and fully kinetic numerical calculations.
Maximal sustained levels of energy expenditure in humans during exercise.
Cooper, Jamie A; Nguyen, David D; Ruby, Brent C; Schoeller, Dale A
2011-12-01
Migrating birds have been able to sustain an energy expenditure (EE) that is five times their basal metabolic rate. Although humans can readily reach these levels, it is not yet clear what levels can be sustained for several days. The study's purposes were 1) to determine the upper limits of human EE and whether or not those levels can be sustained without inducing catabolism of body tissues and 2) to determine whether initial body weight is related to the levels that can be sustained. We compiled data on documented EE as measured by doubly labeled water during high levels of physical activity (minimum of five consecutive days). We calculated the physical activity level (PAL) of each individual studied (PAL = total EE / basal metabolic rate) from the published data. Correlations were run to examine the relationship between initial body weight and body weight lost with both total EE and PAL. The uppermost limit of EE was a peak PAL of 6.94 that was sustained for 10 consecutive days of a 95-d race. Only two studies reported PALs above 5.0; however, significant decreases in body mass were found in each study (0.45-1.39 kg·wk(-1) of weight loss). To test whether initial weight affects the ability to sustain high PALs, we found a significant positive correlation between TEE and initial body weight (r = 0.46, P < 0.05) but no correlation between PAL and body weight (r = 0.27, not statistically significant). Some elite humans are able to sustain PALs above 5.0 for a minimum of 10 d. Although significant decreases in body weight occur at this level, catabolism of body tissue may be preventable in situations with proper energy intake. Further, initial body weight does not seem to affect the sustainability of PALs.
The vibrational energy levels and dissociation energy of O2/+/ /X 2 Pi g/
NASA Technical Reports Server (NTRS)
Samson, J. A. R.; Gardner, J. L.
1977-01-01
The absolute vibrational energy levels of the X 2 Pi g state of O2(+) have been determined by the method of photoelectron spectroscopy in the range nu = 0-25. The precision of the method is comparable to that of conventional high resolution optical spectroscopy. The dissociation energy obtained by a linear extrapolation of the vibrational separations is found to be 6.67 plus or minus 0.18 eV.
Energy levels of ABC-stacked trilayer graphene quantum dots with infinite-mass boundary conditions
NASA Astrophysics Data System (ADS)
Mirzakhani, M.; Zarenia, M.; da Costa, D. R.; Ketabi, S. A.; Peeters, F. M.
2016-10-01
Using the continuum model, we investigate the confined states and the corresponding wave functions of ABC-stacked trilayer graphene (TLG) quantum dots (QDs). First, a general infinite-mass boundary condition is derived and applied to calculate the electron and hole energy levels of a circular QD in both the absence and presence of a perpendicular magnetic field. Our analytical results for the energy spectra agree with those obtained by using the tight-binding model, where a TLG QD is surrounded by a staggered potential. Our findings show that (i ) the energy spectrum exhibits intervalley symmetry EKe(m ) =-EK'h(m ) for the electron (e) and hole (h) states, where m is the angular momentum quantum number, (i i ) the zero-energy Landau level (LL) is formed by the magnetic states with m ⩽0 for both Dirac valleys, that is different from monolayer and bilayer graphene QD with infinite-mass potential in which only one of the cones contributes, and (i i i ) groups of three quantum Hall edge states in the tight-binding magnetic spectrum approach the zero LL, which results from the layer symmetry in TLG QDs.
Zaluzec, Nestor J.; Burke, M. Grace; Haigh, Sarah J.; Kulzick, Matthew
2014-04-01
The use of analytical spectroscopies during scanning/transmission electron microscope (S/TEM) investigations of micro- and nano-scale structures has become a routine technique in the arsenal of tools available to today's materials researchers. Essential to implementation and successful application of spectroscopy to characterization is the integration of numerous technologies, which include electron optics, specimen holders, and associated detectors. While this combination has been achieved in many instrument configurations, the integration of X-ray energy-dispersive spectroscopy and in situ liquid environmental cells in the S/TEM has to date been elusive. In this work we present the successful incorporation/modifications to a system that achieves this functionality for analytical electron microscopy.
Energy levels and radiative rates for transitions in Mo XV
NASA Astrophysics Data System (ADS)
El-Sayed, F.; Attia, S. M.
2017-07-01
Energy levels, wavelengths, transition probabilities, oscillator strengths, line strengths, and lifetimes have been calculated for transitions among the fine-structure levels belonging to the (1s22s22p6)3s23p63d10, 3s23p63d94l, 3s23p53d104l, and 3s3p63d104l (l = s, p, d, f) configurations of the Ni-like Molybdenum, Mo XV. The results for electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transitions among the lowest levels of Mo XV have been reported and compared with available NIST results.
Antimullerian Hormone Level and Endometrioma Ablation Using Plasma Energy
Bubenheim, Michael; Auber, Mathieu; Marpeau, Loïc; Puscasiu, Lucian
2014-01-01
Objective: To investigate the impact of ovarian endometrioma vaporization using plasma energy on antimullerian hormone (AMH) level. Method: We report a prospective, noncomparative series (NCT01596985). Twenty-two patients with unilateral ovarian endometriomas ≥30 mm, with no surgical antecedent and no ongoing pregnancy, underwent vaporization of ovarian endometriomas using plasma energy during the period of November 29, 2010 to November 28, 2012. We assessed AMH levels before surgery, 3 months postoperatively, and at the end of follow-up. Results: The mean length of postoperative follow-up was 18.2 ± 8 months. AMH level significantly varied through the 3 assessments performed in the study, as the mean values ± SD were 3.9 ± 2.6 ng/mL before the surgery, 2.3 ± 1.1 ng/mL at 3 months, and 3.1 ± 2.2 ng/mL at the end of the follow-up (P = .001). There was a significant increase from 3 months postoperatively to the end of follow-up (median change 0.7 ng/mL, P = .01). Seventy-one percent of patients had an AMH level >2 ng/mL at the end of the follow-up versus 76% before the surgery (P = 1). During the postoperative follow-up, 11 patients tried to conceive, of whom 8 (73%) became pregnant. Conclusions: The ablation of unilateral endometriomas is followed in a majority of cases by a significant decrease in AMH level 3 months after surgery. In subsequent months, this level progressively increases, raising questions about the real factors that impact postoperative ovarian AMH production. PMID:25392649
Energy level control: toward an efficient hot electron transport
NASA Astrophysics Data System (ADS)
Jin, Xiao; Li, Qinghua; Li, Yue; Chen, Zihan; Wei, Tai-Huei; He, Xingdao; Sun, Weifu
2014-08-01
Highly efficient hot electron transport represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot electron capture and lost-cost devices remains a technological challenge, regulating the energy level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the `excess' energy offset between the conduction band of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence band and highest occupied molecular orbital. Strikingly, the hot electron transfer time has been shortened. This work demonstrates that suitable energy level alignment can be tuned to gain the higher hot electron/hole transport efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells.
Energy level control: toward an efficient hot electron transport
Jin, Xiao; Li, Qinghua; Li, Yue; Chen, Zihan; Wei, Tai-Huei; He, Xingdao; Sun, Weifu
2014-01-01
Highly efficient hot electron transport represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot electron capture and lost-cost devices remains a technological challenge, regulating the energy level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the ‘excess' energy offset between the conduction band of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence band and highest occupied molecular orbital. Strikingly, the hot electron transfer time has been shortened. This work demonstrates that suitable energy level alignment can be tuned to gain the higher hot electron/hole transport efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells. PMID:25099864
Energy level control: toward an efficient hot electron transport.
Jin, Xiao; Li, Qinghua; Li, Yue; Chen, Zihan; Wei, Tai-Huei; He, Xingdao; Sun, Weifu
2014-08-07
Highly efficient hot electron transport represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot electron capture and lost-cost devices remains a technological challenge, regulating the energy level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the 'excess' energy offset between the conduction band of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence band and highest occupied molecular orbital. Strikingly, the hot electron transfer time has been shortened. This work demonstrates that suitable energy level alignment can be tuned to gain the higher hot electron/hole transport efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells.
Vintage-level energy and environmental performance of manufacturing establishments
Boyd, G.A.; Bock, M.J.; Neifer, M.J.; Karlson, S.H.; Ross, M.H.
1994-05-01
This report examines the relationship between an industrial plant`s vintage and its energy and environmental performance. Basic questions related to defining vintage and measuring the effects of the manufacturing industry`s vintage distribution of plant-level capacity and energy intensity are explored in general for six energy-intensive sectors (paper, chlorine, nitrogenous fertilizer, aluminum, steel, and cement) at the four-digit standard industrial classification (SIC) level and in detail for two sectors (steel and cement). Results show that greenfield (i.e., newly opened) plants in the paper, steel, and cement industries exhibit low fossil fuel intensities. These results are consistent with expectations. New plants in the paper and steel industries, where processes are undergoing electrification, exhibit high electricity intensities. An analysis of a subsector of the steel industry -- minimills that use scrap-based, electric arc furnaces -- reveals a decline in electricity intensity of 6.2 kilowatt-hours per ton for each newer year of installed vintage. This estimate is consistent with those of engineering studies and raises confidence that analyses of vintage effects in other industries could be conducted. When a vintage measure is assigned on the basis of investment data rather than trade association data, the vintage/performance relationship results for the cement industry are reasonably robust; thus, the analysis of vintage and performance could be extended to sectors for which only US Bureau of the Census data are available.
Cheng, Lan; Gauss, Jürgen
2011-08-28
We report the implementation of analytic energy gradients for the evaluation of first-order electrical properties and nuclear forces within the framework of the spin-free (SF) exact two-component (X2c) theory. In the scheme presented here, referred to in the following as SFX2c-1e, the decoupling of electronic and positronic solutions is performed for the one-electron Dirac Hamiltonian in its matrix representation using a single unitary transformation. The resulting two-component one-electron matrix Hamiltonian is combined with untransformed two-electron interactions for subsequent self-consistent-field and electron-correlated calculations. The "picture-change" effect in the calculation of properties is taken into account by considering the full derivative of the two-component Hamiltonian matrix with respect to the external perturbation. The applicability of the analytic-gradient scheme presented here is demonstrated in benchmark calculations. SFX2c-1e results for the dipole moments and electric-field gradients of the hydrogen halides are compared with those obtained from nonrelativistic, SF high-order Douglas-Kroll-Hess, and SF Dirac-Coulomb calculations. It is shown that the use of untransformed two-electron interactions introduces rather small errors for these properties. As a first application of the analytic geometrical gradient, we report the equilibrium geometry of methylcopper (CuCH(3)) determined at various levels of theory.
Lighting system replacement brings energy costs down, light levels up
Radmer, D.J.
1984-11-08
The R.J. Frisby Mfg. Co. operates on three shifts and produces precision screw machine products for a variety of industries, including automotive, marine, machine tool, hydraulics and pneumatics, business machines, electrical and electronics, photography, and precision instruments. The required degree of manufacturing precision demands high light levels in manufacturing areas. When the 100,000 sq ft plant was built in 1973, mercury vapor lighting was installed consistent with the current state of the art for lighting such facilities. In the ensuing years, it became apparent that the soaring electric bills that came in the wake of the Arab oil embargo of 1973-74 would have to be controlled. Estimates by the U.S. Department of Energy indicated that electric energy costs were likely to rise by 160 percent over the next 10 yr. Based on this estimate, and the fact that lighting accounted for $70,000, or half of the annual electric bill, it was estimated that $900,000 to $1,000,000 would be spent for lighting energy over the next decade. The concern over the probability of rapidly escalating electrical costs was soon justified when, in three steps over one 12 mo period, the electric energy rate increased from $0.0305/kwh to $0.0416/kwh -more than a 36 percent increase. During that same period, the demand charge was raised in two steps from $3.75/kw to $4.85/kw --more than a 29 percent increase.
Oftedal, O T; Eisert, R; Barrell, G K
2014-01-01
Mammalian milks may differ greatly in composition from cow milk, and these differences may affect the performance of analytical methods. High-fat, high-protein milks with a preponderance of oligosaccharides, such as those produced by many marine mammals, present a particular challenge. We compared the performance of several methods against reference procedures using Weddell seal (Leptonychotes weddellii) milk of highly varied composition (by reference methods: 27-63% water, 24-62% fat, 8-12% crude protein, 0.5-1.8% sugar). A microdrying step preparatory to carbon-hydrogen-nitrogen (CHN) gas analysis slightly underestimated water content and had a higher repeatability relative standard deviation (RSDr) than did reference oven drying at 100°C. Compared with a reference macro-Kjeldahl protein procedure, the CHN (or Dumas) combustion method had a somewhat higher RSDr (1.56 vs. 0.60%) but correlation between methods was high (0.992), means were not different (CHN: 17.2±0.46% dry matter basis; Kjeldahl 17.3±0.49% dry matter basis), there were no significant proportional or constant errors, and predictive performance was high. A carbon stoichiometric procedure based on CHN analysis failed to adequately predict fat (reference: Röse-Gottlieb method) or total sugar (reference: phenol-sulfuric acid method). Gross energy content, calculated from energetic factors and results from reference methods for fat, protein, and total sugar, accurately predicted gross energy as measured by bomb calorimetry. We conclude that the CHN (Dumas) combustion method and calculation of gross energy are acceptable analytical approaches for marine mammal milk, but fat and sugar require separate analysis by appropriate analytic methods and cannot be adequately estimated by carbon stoichiometry. Some other alternative methods-low-temperature drying for water determination; Bradford, Lowry, and biuret methods for protein; the Folch and the Bligh and Dyer methods for fat; and enzymatic and reducing
Energy transfer and energy level decay processes of Er3+ in water-free tellurite glass
NASA Astrophysics Data System (ADS)
Gomes, Laercio; Rhonehouse, Daniel; Nguyen, Dan T.; Zong, Jie; Chavez-Pirson, Arturo; Jackson, Stuart D.
2015-12-01
This report details the fundamental spectroscopic properties of a new class of water-free tellurite glasses studied for future applications in mid-infrared light generation. The fundamental excited state decay processes relating to the 4I11/2 → 4I13/2 transition in singly Er3+-doped Tellurium Zinc Lanthanum glass have been investigated using time-resolved fluorescence spectroscopy. The excited state dynamics was analyzed for Er2O3 concentrations between 0.5 mol% and 4 mol%. Selective laser excitation of the 4I11/2 energy level at 972 nm and selective laser excitation of the 4I13/2 energy level at 1485 nm has established that in a similar way to other Er3+-doped glasses, a strong energy-transfer upconversion by way of a dipole-dipole interaction between two excited erbium ions in the 4I13/2 level populates the 4I11/2 upper laser level of the 3 μm transition. The 4I13/2 and 4I11/2 energy levels emitted luminescence with peaks located at 1532 nm and 2734 nm respectively with luminescence efficiencies of 100% and 8% for the higher (4 mol.%) concentration sample. Results from numerical simulations showed that a population inversion is reached at a threshold pumping intensity of ∼57 kW cm-2 for a CW laser pump at 976 nm for [Er2O3] = 2 mol.%.
Modification of Coulomb law and energy levels of the hydrogen atom in a superstrong magnetic field
Machet, B.; Vysotsky, M. I.
2011-01-15
We obtain the following analytical formula which describes the dependence of the electric potential of a pointlike charge on the distance away from it in the direction of an external magnetic field B: {Phi}(z)=e/|z|[1-exp(-{radical}(6m{sub e}{sup 2})|z|)+exp(-{radical}((2/{pi})e{sup 3}B+6m{sub e}{sup 2})|z|)]. The deviation from Coulomb's law becomes essential for B>3{pi}B{sub cr}/{alpha}=3{pi}m{sub e}{sup 2}/e{sup 3{approx_equal}}6x10{sup 16} G. In such superstrong fields, electrons are ultrarelativistic except those which occupy the lowest Landau level (LLL) and which have the energy {epsilon}{sub 0}{sup 2}=m{sub e}{sup 2}+p{sub z}{sup 2}. The energy spectrum on which LLL splits in the presence of the atomic nucleus is found analytically. For B>3{pi}B{sub cr}/{alpha} it differs substantially from the one obtained without accounting for the modification of the atomic potential.
Characterizing and modeling subarea-level energy transactions.
Kavicky, J. A.
1998-03-05
This paper describes the application of an electrical network characterization method to an optimization model that is designed to simulate subarea-level energy transactions. The network characterization method determines subarea clusters of system buses that electrically respond to perturbations in a very similar manner. The method produces a reduced number of transmission constraints and preserves parallel path representations. The least-cost, linear programming (LP) formulation takes advantage of data reduction techniques to simplify model transmission constraints, while supporting parallel path system characteristics and energy tagging of subarea transactions. An overview of the proposed method describes the problem domain and key model features. The paper then presents two model applications that illustrate generator siting and line overload screening analyses.
Fermi level stabilization energy in group III-nitrides
Li, S.X.; Yu, K.M.; Wu, J.; Jones, R.E.; Walukiewicz, W.; AgerIII, J.W.; Shan, W.; Haller, E.E.; Lu, Hai; Schaff, William J.
2005-01-07
Energetic particle irradiation is used to systematically introduce point defects into In{sub 1-x}Ga{sub x}N alloys over the entire composition range. Three types of energetic particles (electrons, protons, and {sup 4}He{sup +}) are used to produce a displacement damage dose spanning five decades. In InN and In-rich InGaN the free electron concentration increases with increasing irradiation dose but saturates at a sufficiently high dose. The saturation is due to Fermi level pinning at the Fermi Stabilization Energy (E{sub FS}), which is located at 4.9 eV below the vacuum level. Electrochemical capacitance-voltage (ECV) measurements show that the pinning of the surface Fermi energy at E{sub FS} is also responsible for the surface electron accumulation in as-grown InN and In-rich InGaN alloys. The results are in agreement with the amphoteric defect model that predicts that the same type of native defects are responsible for the Fermi level pinning in both cases.
Analytical on-shell calculation of low energy higher order scattering
NASA Astrophysics Data System (ADS)
Holstein, Barry R.
2017-01-01
We demonstrate that the use of analytical on-shell methods involving calculation of the discontinuity across the t-channel cut associated with the exchange of a pair of massless particles (photons or gravitons) can be used to evaluate one-loop contributions to electromagnetic and gravitational scattering, with and without polarizability, reproducing via simple algebraic manipulations, results obtained previously, generally using Feynman diagram techniques. In the gravitational case the use of factorization permits a straightforward and algebraic calculation of higher order scattering without consideration of ghost contributions or of triple-graviton couplings, which made previous evaluations considerably more arduous.
Analytical approximations for the long-term decay behavior of spent fuel and high-level waste
Malbrain, C.M.; Deutch, J.M.; Lester, R.K.
1982-05-01
Simple analytical approximations are presented that describe the radioactivity and radiogenic decay heat behavior of high-level wastes (HLWs) from various nuclear fuel cycles during the first 100,000 years of waste life. The correlations are based on detailed computations of HLW properties carried out with the isotope generation and depletion code ORIGEN 2. The ambiguities encountered in using simple comparisons of the hazards posed by HLWs and naturally occurring mineral deposits to establish the longevity requirements for geologic waste disposal schemes are discussed.
NASA Astrophysics Data System (ADS)
Nakata, Hiroya; Nishimoto, Yoshio; Fedorov, Dmitri G.
2016-07-01
The analytic second derivative of the energy is developed for the fragment molecular orbital (FMO) method combined with density-functional tight-binding (DFTB), enabling simulations of infrared and Raman spectra of large molecular systems. The accuracy of the method is established in comparison to full DFTB without fragmentation for a set of representative systems. The performance of the FMO-DFTB Hessian is discussed for molecular systems containing up to 10 041 atoms. The method is applied to the study of the binding of α-cyclodextrin to polyethylene glycol, and the calculated IR spectrum of an epoxy amine oligomer reproduces experiment reasonably well.
Nakata, Hiroya; Nishimoto, Yoshio; Fedorov, Dmitri G
2016-07-28
The analytic second derivative of the energy is developed for the fragment molecular orbital (FMO) method combined with density-functional tight-binding (DFTB), enabling simulations of infrared and Raman spectra of large molecular systems. The accuracy of the method is established in comparison to full DFTB without fragmentation for a set of representative systems. The performance of the FMO-DFTB Hessian is discussed for molecular systems containing up to 10 041 atoms. The method is applied to the study of the binding of α-cyclodextrin to polyethylene glycol, and the calculated IR spectrum of an epoxy amine oligomer reproduces experiment reasonably well.
Radiative lifetime and energy of the low-energy isomeric level in 229Th
NASA Astrophysics Data System (ADS)
Tkalya, E. V.; Schneider, Christian; Jeet, Justin; Hudson, Eric R.
2015-11-01
We estimate the range of the radiative lifetime and energy of the anomalous, low-energy 3 /2+(7.8 ±0.5 eV) state in the 229Th nucleus. Our phenomenological calculations are based on the available experimental data for the intensities of M 1 and E 2 transitions between excited levels of the 229Th nucleus in the Kπ[N nZΛ ] =5 /2+[633 ] and 3 /2+[631 ] rotational bands. We also discuss the influence of certain branching coefficients, which affect the currently accepted measured energy of the isomeric state. From this work, we establish a favored region, 0.66 ×106seV3/ω3≤τ ≤2.2 ×106seV3/ω3 , where the transition lifetime τ as a function of transition energy ω should lie at roughly the 95% confidence level. Together with the result of Beck et al. [LLNL-PROC-415170 (2009)], we establish a favored area where transition lifetime and energy should lie at roughly the 90% confidence level. We also suggest new nuclear physics measurements, which would significantly reduce the ambiguity in the present data.
Santarius, Tilman
2015-03-30
Increasing energy efficiency in households, transportation, industries, and services is an important strategy to reduce energy service demand to levels that allow the steep reduction of greenhouse gases, and a full fledged switch of energy systems to a renewable basis. Yet, technological efficiency improvements may generate so-called rebound effects, which may ‘eat up’ parts of the technical savings potential. This article provides a comprehensive review of existing research on these effects, raises critiques, and points out open questions. It introduces micro-economic rebound effect and suggests extending consumer-side analysis to incorporate potential ‘psychological rebound effects.’ It then discusses meso-economic rebound effects, i.e. producer-side and market-level rebounds, which so far have achieved little attention in the literature. Finally, the article critically reviews evidence for macro-economic rebound effects as energy efficiency-induced economic growth impacts. For all three categories, the article summarizes assessments of their potential quantitative scope, while pointing out remaining methodological weaknesses and open questions. As a rough “rule of thumb”, in the long term and on gross average, only half the technical savings potential of across-the-board efficiency improvements may actually be achieved in the real world. Policies that aim at cutting energy service demand to sustainable levels are well advised to take due note of detrimental behavioral and economic growth impacts, and should foster policies and measures that can contain them.
NASA Astrophysics Data System (ADS)
Santarius, Tilman
2015-03-01
Increasing energy efficiency in households, transportation, industries, and services is an important strategy to reduce energy service demand to levels that allow the steep reduction of greenhouse gases, and a full fledged switch of energy systems to a renewable basis. Yet, technological efficiency improvements may generate so-called rebound effects, which may `eat up' parts of the technical savings potential. This article provides a comprehensive review of existing research on these effects, raises critiques, and points out open questions. It introduces micro-economic rebound effect and suggests extending consumer-side analysis to incorporate potential `psychological rebound effects.' It then discusses meso-economic rebound effects, i.e. producer-side and market-level rebounds, which so far have achieved little attention in the literature. Finally, the article critically reviews evidence for macro-economic rebound effects as energy efficiency-induced economic growth impacts. For all three categories, the article summarizes assessments of their potential quantitative scope, while pointing out remaining methodological weaknesses and open questions. As a rough "rule of thumb", in the long term and on gross average, only half the technical savings potential of across-the-board efficiency improvements may actually be achieved in the real world. Policies that aim at cutting energy service demand to sustainable levels are well advised to take due note of detrimental behavioral and economic growth impacts, and should foster policies and measures that can contain them.
Accurate energy levels for singly ionized platinum (Pt II)
NASA Technical Reports Server (NTRS)
Reader, Joseph; Acquista, Nicolo; Sansonetti, Craig J.; Engleman, Rolf, Jr.
1988-01-01
New observations of the spectrum of Pt II have been made with hollow-cathode lamps. The region from 1032 to 4101 A was observed photographically with a 10.7-m normal-incidence spectrograph. The region from 2245 to 5223 A was observed with a Fourier-transform spectrometer. Wavelength measurements were made for 558 lines. The uncertainties vary from 0.0005 to 0.004 A. From these measurements and three parity-forbidden transitions in the infrared, accurate values were determined for 28 even and 72 odd energy levels of Pt II.
Charge retention in quantized energy levels of nanocrystals
NASA Astrophysics Data System (ADS)
Dâna, Aykutlu; Akça, İmran; Ergun, Orçun; Aydınlı, Atilla; Turan, Raşit; Finstad, Terje G.
2007-04-01
Understanding charging mechanisms and charge retention dynamics of nanocrystal (NC) memory devices is important in optimization of device design. Capacitance spectroscopy on PECVD grown germanium NCs embedded in a silicon oxide matrix was performed. Dynamic measurements of discharge dynamics are carried out. Charge decay is modelled by assuming storage of carriers in the ground states of NCs and that the decay is dominated by direct tunnelling. Discharge rates are calculated using the theoretical model for different NC sizes and densities and are compared with experimental data. Experimental results agree well with the proposed model and suggest that charge is indeed stored in the quantized energy levels of the NCs.
Energy levels of an anisotropic three-dimensional polaron in a magnetic field
NASA Astrophysics Data System (ADS)
Brancus, D. E.; Stan, G.
2001-06-01
In the context of the improved Wigner-Brillouin theory, the energy levels are found of a Fröhlich polaron in a uniaxial anisotropic polar semiconductor with complex structure, placed in a magnetic field directed either along the optical axis or orthogonal to it. All sources of anisotropy that are contained in the shape of constant-energy surfaces of the bare electron, the electron-optical-phonon interaction, and the frequency spectrum of the extraordinary phonon modes are considered. Analytical results for the electron-phonon interaction correction to the Landau levels below the optical-phonon continuum are given and, numerical results for the magnetic-field dependence of the cyclotron resonance frequency at low temperature are presented for the particular case of the layered semiconductors InSe and GaSe. Although the interaction between the bare electron and quasitransverse optical-phonon modes is weak, these modes play an important role in the pinning of Landau levels. The results given by Das Sarma for a two-dimensional isotropic magnetopolaron are generalized to the anisotropic uniaxial case by taking formally m∥-->∞ in the expression of the perturbed Landau levels found when the magnetic field is directed along the optical axis, m∥ being the component of the bare-electron effective-mass tensor along the optical axis.
Gupta, Varun; Gupta, Kanchan; Singh, Gagandeep; Kaushal, Sandeep
2016-01-01
Introduction: With the advancement of therapeutics, newer antiepileptic drugs (AEDs) like Levetiracetam (LEV), with good therapeutic efficacy and tolerability are available. But unfortunately, therapeutic drug monitoring is not routinely done in India for these drugs. Objectives: The objective of this study is to determine the range of serum levels of LEV in patients at stabilized doses and correlate them with their clinical course. Materials and Methods: Patients with epilepsy and started on LEV were enrolled from the Neurology Department after the Ethics Committee approval. Serum levels of LEV were estimated using high-performance liquid chromatography and correlated with patient demographics, dosage, dosage forms, concomitant AEDs, compliance of the patient, therapeutic effect, adverse drug reactions (ADRs), and suspected toxicity. Results: Serum levels of LEV ranged from 0.4 to 102.2 μg/ml at different time points and demonstrated a negligible positive correlation with age of the patients (r = 0.12) but negligible negative correlation with bodyweight (r = −0.19). No conclusive relationship could be established for dose, gender, dosage forms, clinical efficacy (seizure frequency), ADRs, and toxicity. Compliance was verified in all the patients. Levels were found to reduce with the use of concomitant enzyme inducer drugs (56.78%) whereas increase with valproic acid (7.8%). Conclusion: These findings emphasize the need for monitoring the serum levels of newer AEDs like LEV considering the various parameters studied here, so as to maintain the therapeutic efficacy by preventing under or over dosage and to generate a broader database of serum levels of LEV in the Indian population to help appropriate prescribing with more confidence. PMID:28163500
NASA Technical Reports Server (NTRS)
Coggi, J. V.; Loscutoff, A. V.; Barker, R. S.
1973-01-01
An analytical simulation of the RITE-Integrated Waste Management and Water Recovery System using radioisotopes for thermal energy was prepared for the NASA-Manned Space Flight Center (MSFC). The RITE system is the most advanced concept water-waste management system currently under development and has undergone extended duration testing. It has the capability of disposing of nearly all spacecraft wastes including feces and trash and of recovering water from usual waste water sources: urine, condensate, wash water, etc. All of the process heat normally used in the system is produced from low penalty radioisotope heat sources. The analytical simulation was developed with the G189A computer program. The objective of the simulation was to obtain an analytical simulation which can be used to (1) evaluate the current RITE system steady state and transient performance during normal operating conditions, and also during off normal operating conditions including failure modes; and (2) evaluate the effects of variations in component design parameters and vehicle interface parameters on system performance.
Analytical mechanics and field theory: derivation of equations from energy conservation
NASA Astrophysics Data System (ADS)
Vinokurov, N. A.
2014-06-01
Equations of motion in mechanics and field equations in field theory are conventionally derived using the least action principle. This paper presents a nonvariational derivation of Hamilton's and Lagrange's equations. The derivation starts by specifying the system energy as a function of generalized coordinates and velocities and then introduces generalized momenta in such a way that the energy remains unchanged under variations of any degree of freedom. This immediately leads to Hamilton's equations with an as yet undefined Hamiltonian. The explicit dependence of generalized momenta on the coordinates and velocities is determined by first finding the Lagrangian from the known energy function. We discuss electrodynamics as an illustrative example. The proposed approach provides new insight into the nature of canonical momenta and offers a way to find the Lagrangian from the known energy of the system.
Using Job Analytic Perceptions to Predict Stressor Levels among Factory Supervisors.
ERIC Educational Resources Information Center
Love, Kevin G.; And Others
Job stress is recognized as a primary roadblock to achieving job satisfaction. In order to investigate the linkage between important job characteristics and stressor levels, 378 factory supervisors (aged 45-54; 89 percent male; 93 percent white with an average of 21 years with the company) completed a two-part job analysis questionnaire. In the…
Impact of battery degradation on energy arbitrage revenue of grid-level energy storage
Wankmüller, Florian; Thimmapuram, Prakash R.; Gallagher, Kevin G.; ...
2017-01-19
This study investigates the representation of battery degradation in grid level energy storage applications. In particular, we focus on energy arbitrage, as this is a potential future large-scale application of energy storage and there is limited existing research combining the modelling of battery degradation and energy storage arbitrage. We implement two different representations of battery degradation within an energy arbitrage model, and show that degradation has a strong impact on battery energy storage system (BESS) profitability. In a case study using historical electricity market prices from the MISO electricity market in the United States, we find that the achievable netmore » present value (at an interest rate of 10%) for a battery system with a C-rate of 1C dropped from 358 /kWh in the case considering no degradation to 194-314 /kWh depending on the battery degradation model and assumptions for end of life (EOL) criteria. This corresponds to a reduction in revenue due to degradation in the 12-46% range.Furthermore, we find that reducing the cycling of the bat-tery via introducing a penalty cost in the objective function of the energy arbitrage optimization model can improve the profitability over the life of the BESS.« less
The analytical model for vortex ring pinch-off process based on the energy extremum principle
NASA Astrophysics Data System (ADS)
Xiang, Yang; Liu, Hong; Qin, Suyang; Wang, Fuxin
2015-11-01
The discovery of vortex ring pinch-off is greatly helpful for us to understand the mechanism of optimal vortex formation, which further implies the optimal biological propulsion for animals. The vortex ring pinch-off implies its limiting formation and is dominated by the energy extremum principle. However, it is found that vortex ring pinch-off is a continuous process rather than a transient timescale. Therefore, we are wondering that how to identify the onset and end of pinch-off process. Based on the Kelvin-Benjamin variational principle, a dimensionless energy number is adopted to characterize the energy evolution of vortex rings. The vortex ring flow fields are obtained by DPIV with the piston-cylinder setup, and their geometric structures are identified using its Lagrangian coherent structures. The results show that the dimensionless energy numbers with the steady translating vortex rings share a critical value. It is then demonstrated that the dimensionless energy number dominates the onset and the end of pinch-off process. Besides, the onset and end of pinch-off can also be identified using LCSs. Additionally, based on the dimensionless energy number or LCSs, the corresponding vortex ring formation times(L/D) for the onset or the end of pinch-off are consistent.
NASA Astrophysics Data System (ADS)
Yamamoto, Takeshi
2008-12-01
Conventional quantum chemical solvation theories are based on the mean-field embedding approximation. That is, the electronic wavefunction is calculated in the presence of the mean field of the environment. In this paper a direct quantum mechanical/molecular mechanical (QM/MM) analog of such a mean-field theory is formulated based on variational and perturbative frameworks. In the variational framework, an appropriate QM/MM free energy functional is defined and is minimized in terms of the trial wavefunction that best approximates the true QM wavefunction in a statistically averaged sense. Analytical free energy gradient is obtained, which takes the form of the gradient of effective QM energy calculated in the averaged MM potential. In the perturbative framework, the above variational procedure is shown to be equivalent to the first-order expansion of the QM energy (in the exact free energy expression) about the self-consistent reference field. This helps understand the relation between the variational procedure and the exact QM/MM free energy as well as existing QM/MM theories. Based on this, several ways are discussed for evaluating non-mean-field effects (i.e., statistical fluctuations of the QM wavefunction) that are neglected in the mean-field calculation. As an illustration, the method is applied to an SN2 Menshutkin reaction in water, NH3+CH3Cl→NH3CH3++Cl-, for which free energy profiles are obtained at the Hartree-Fock, MP2, B3LYP, and BHHLYP levels by integrating the free energy gradient. Non-mean-field effects are evaluated to be <0.5 kcal/mol using a Gaussian fluctuation model for the environment, which suggests that those effects are rather small for the present reaction in water.
NASA Astrophysics Data System (ADS)
Papp, P.; Matejčík, Š.; Mach, P.; Urban, J.; Paidarová, I.; Horáček, J.
2013-06-01
The method of analytic continuation in the coupling constant (ACCC) in combination with use of the statistical Padé approximation is applied to the determination of resonance energy and width of some amino acids and formic acid dimer. Standard quantum chemistry codes provide accurate data which can be used for analytic continuation in the coupling constant to obtain the resonance energy and width of organic molecules with a good accuracy. The obtained results are compared with the existing experimental ones.
Steward, D.; Zuboy, J.
2014-10-01
Energy storage could complement PV electricity generation at the community level. Because PV generation is intermittent, strategies must be implemented to integrate it into the electricity system. Hydrogen and fuel cell technologies offer possible PV integration strategies, including the community-level approaches analyzed in this report: (1) using hydrogen production, storage, and reconversion to electricity to level PV generation and grid loads (reconversion scenario); (2) using hydrogen production and storage to capture peak PV generation and refuel hydrogen fuel cell electric vehicles (FCEVs) (hydrogen fueling scenario); and (3) a comparison scenario using a battery system to store electricity for EV nighttime charging (electric charging scenario).
NASA Astrophysics Data System (ADS)
Ooi, B. L.; Gilbert, J. M.; Aziz, A. Rashid A.
2016-08-01
Owing to the increasing demand for harvesting energy from environmental vibration for use in self-powered electronic applications, cantilever-based vibration energy harvesting has attracted considerable interest from various parties and has become one of the most common approaches to converting redundant mechanical energy into electrical energy. As the output voltage produced from a piezoelectric material depends largely on the geometric shape and the size of the beam, there is a need to model and compare the performance of cantilever beams of differing geometries. This paper presents the study of strain distribution in various shapes of cantilever beams, including a convex and concave edge profile elliptical beam that have not yet been discussed in any prior literature. Both analytical and finite-element models are derived and the resultant strain distributions in the beam are computed based on a MATLAB solver and ANSYS finite-element analysis tools. An optimum geometry for a vibration-based energy harvesting system is verified. Finally, experimental results comparing the power density for triangular and rectangular piezoelectric beams are also presented to validate the findings of the study, and the claim, as suggested in the literature, is verified.
NASA Astrophysics Data System (ADS)
Zeng, Hui; Zhao, Jun
2012-07-01
In this paper, the energy, equilibrium geometry, and harmonic frequency of the ground electronic state of PO2 are computed using the B3LYP, B3P86, CCSD(T), and QCISD(T) methods in conjunction with the 6-311++G(3df, 3pd) and cc-pVTZ basis sets. A comparison between the computational results and the experimental values indicates that the B3P86/6-311++G(3df, 3pd) method can give better energy calculation results for the PO2 molecule. It is shown that the ground state of the PO2 molecule has C2ν symmetry and its ground electronic state is X2A1. The equilibrium parameters of the structure are RP-O = 0.1465 nm, ∠OPO = 134.96°, and the dissociation energy is Ed = 19.218 eV. The bent vibrational frequency ν1 = 386 cm-1, symmetric stretching frequency ν2 = 1095 cm-1, and asymmetric stretching frequency ν3 = 1333 cm-1 are obtained. On the basis of atomic and molecular reaction statics, a reasonable dissociation limit for the ground state of the PO2 molecule is determined. Then the analytic potential energy function of the PO2 molecule is derived using many-body expansion theory. The potential curves correctly reproduce the configurations and the dissociation energy for the PO2 molecule.
The Analytic Onion: Examining Training Issues from Different Levels of Analysis
1991-09-01
societies is found In sociology, economics, political science, anthropology, and history . The world system Is the next level of analysis. The world system...place. The norms, roles, statuses, values, history , and required technical abilities are transmitted to the younger generation during education. There...new patterns will develop. Initially, space colonies will be greatly dependent on mother earth but if history is any teacher (as Santayana says it is
Molecular structure and analytical potential energy function of SeCO
NASA Astrophysics Data System (ADS)
Zhang, Heng; Tian, Duan-Liang; Yan, Shi-Ying
2014-09-01
The density functional method (B3P86/6-311G) is used for calculating the possible structures of SeC, SeO, and SeCO molecules. The result shows that the ground state of the SeC molecule is 1Σ, the equilibrium nuclear distance is RSeC = 0.1699 nm, and the dissociation energy is De = 8.7246 eV. The ground state of the SeO molecule is 3Σ, with equilibrium nuclear distance RSeO = 0.1707 nm and dissociation energy De = 7.0917 eV. There are two structures for the ground state of the SeCO molecule: Se=C=O and Se=O=C. The linear Se=C=O is 1Σ. Its equilibrium nuclear distances and dissociation energy are RSeC = 0.1715 nm, RCO = 0.1176 nm and 18.8492 eV, respectively. The other structure Se=O=C is 1Σ. Its equilibrium nuclear distances and dissociation energy are RCO = 0.1168 nm, RSeO = 0.1963 nm and 15.5275 eV, respectively. The possible dissociative limit of the SeCO molecule is analyzed. The potential energy function for the SeCO molecule has been obtained from the many-body expansion theory. The contour of the potential energy curve describes the structure characters of the SeCO molecule. Furthermore, contours of the molecular stretching vibration based on this potential energy function are discussed.
Ciccotti, Giovanni; Meloni, Simone
2011-04-07
We introduce a new method to simulate the physics of rare events. The method, an extension of the Temperature Accelerated Molecular Dynamics, comes in use when the collective variables introduced to characterize the rare events are either non-analytical or so complex that computing their derivative is not practical. We illustrate the functioning of the method by studying the homogeneous crystallization in a sample of Lennard-Jones particles. The process is studied by introducing a new collective variable that we call Effective Nucleus Size N. We have computed the free energy barriers and the size of critical nucleus, which result in agreement with data available in the literature. We have also performed simulations in the liquid domain of the phase diagram. We found a free energy curve monotonically growing with the nucleus size, consistent with the liquid domain.
A new analytical potential energy surface for the singlet state of He{sub 2}H{sup +}
Liang Jingjuan; Zhang Qinggang; Yang Chuanlu; Wang Lizhi
2012-03-07
The analytic potential energy surface (APES) for the exchange reaction of HeH{sup +} (X{sup 1}{Sigma}{sup +}) + He at the lowest singlet state 1{sup 1}A{sup /} has been built. The APES is expressed as Aguado-Paniagua function based on the many-body expansion. Using the adaptive non-linear least-squares algorithm, the APES is fitted from 15 682 ab initio energy points calculated with the multireference configuration interaction calculation with a large d-aug-cc-pV5Z basis set. To testify the new APES, we calculate the integral cross sections for He + H{sup +}He (v= 0, 1, 2, j= 0) {yields} HeH{sup +}+ He by means of quasi-classical trajectory and compare them with the previous result in literature.
Analytic energy gradients for the orbital-optimized third-order Møller-Plesset perturbation theory
NASA Astrophysics Data System (ADS)
Bozkaya, Uǧur
2013-09-01
Analytic energy gradients for the orbital-optimized third-order Møller-Plesset perturbation theory (OMP3) [U. Bozkaya, J. Chem. Phys. 135, 224103 (2011)], 10.1063/1.3665134 are presented. The OMP3 method is applied to problematic chemical systems with challenging electronic structures. The performance of the OMP3 method is compared with those of canonical second-order Møller-Plesset perturbation theory (MP2), third-order Møller-Plesset perturbation theory (MP3), coupled-cluster singles and doubles (CCSD), and coupled-cluster singles and doubles with perturbative triples [CCSD(T)] for investigating equilibrium geometries, vibrational frequencies, and open-shell reaction energies. For bond lengths, the performance of OMP3 is in between those of MP3 and CCSD. For harmonic vibrational frequencies, the OMP3 method significantly eliminates the singularities arising from the abnormal response contributions observed for MP3 in case of symmetry-breaking problems, and provides noticeably improved vibrational frequencies for open-shell molecules. For open-shell reaction energies, OMP3 exhibits a better performance than MP3 and CCSD as in case of barrier heights and radical stabilization energies. As discussed in previous studies, the OMP3 method is several times faster than CCSD in energy computations. Further, in analytic gradient computations for the CCSD method one needs to solve λ-amplitude equations, however for OMP3 one does not since λ _{ab}^{ij(1)} = t_{ij}^{ab(1)} and λ _{ab}^{ij(2)} = t_{ij}^{ab(2)}. Additionally, one needs to solve orbital Z-vector equations for CCSD, but for OMP3 orbital response contributions are zero owing to the stationary property of OMP3. Overall, for analytic gradient computations the OMP3 method is several times less expensive than CCSD (roughly ˜4-6 times). Considering the balance of computational cost and accuracy we conclude that the OMP3 method emerges as a very useful tool for the study of electronically challenging chemical
Analytic energy gradients for the orbital-optimized third-order Møller-Plesset perturbation theory.
Bozkaya, Uğur
2013-09-14
Analytic energy gradients for the orbital-optimized third-order Møller-Plesset perturbation theory (OMP3) [U. Bozkaya, J. Chem. Phys. 135, 224103 (2011)] are presented. The OMP3 method is applied to problematic chemical systems with challenging electronic structures. The performance of the OMP3 method is compared with those of canonical second-order Møller-Plesset perturbation theory (MP2), third-order Møller-Plesset perturbation theory (MP3), coupled-cluster singles and doubles (CCSD), and coupled-cluster singles and doubles with perturbative triples [CCSD(T)] for investigating equilibrium geometries, vibrational frequencies, and open-shell reaction energies. For bond lengths, the performance of OMP3 is in between those of MP3 and CCSD. For harmonic vibrational frequencies, the OMP3 method significantly eliminates the singularities arising from the abnormal response contributions observed for MP3 in case of symmetry-breaking problems, and provides noticeably improved vibrational frequencies for open-shell molecules. For open-shell reaction energies, OMP3 exhibits a better performance than MP3 and CCSD as in case of barrier heights and radical stabilization energies. As discussed in previous studies, the OMP3 method is several times faster than CCSD in energy computations. Further, in analytic gradient computations for the CCSD method one needs to solve λ-amplitude equations, however for OMP3 one does not since λ(ab)(ij(1))=t(ij)(ab(1)) and λ(ab)(ij(2))=t(ij)(ab(2)). Additionally, one needs to solve orbital Z-vector equations for CCSD, but for OMP3 orbital response contributions are zero owing to the stationary property of OMP3. Overall, for analytic gradient computations the OMP3 method is several times less expensive than CCSD (roughly ~4-6 times). Considering the balance of computational cost and accuracy we conclude that the OMP3 method emerges as a very useful tool for the study of electronically challenging chemical systems.
Energy level spacing distribution at the quantum Hall transition
NASA Astrophysics Data System (ADS)
Roemer, Rudolf A.; Cain, Philipp; Raikh, Mikhail E.; Schreiber, Michael
2002-03-01
We apply the renormalization group (RG) approach to study the energy level statistics at the integer quantum Hall transition. Within the RG approach the macroscopic array of saddle points of the Chalker-Coddington network is replaced by a fragment consisting of only five saddle points. Previously we have demonstrated that the RG approach reproduces the distribution of the power transmission coefficients at the transition, P(T), with very high accuracy.(P. Cain, M.E. Raikh, R.A. Roemer, M. Schreiber, Phys. Rev. B 64), 235326-9 (2001). To assess the level statistics we analyze the phases of the transmission coefficients. We find that, at the transition, the level spacing distribution (LSD) is close to that for the unitary ensemble with well-pronounced level repulsion. We emphasize that a metal-like LSD emerges when the fixed point distribution P(T) is used. We check that away from the transition the LSD crosses over towards the Poisson distribution.
Noppe, H; Verheyden, K; Gillis, W; Courtheyn, D; Vanthemsche, P; De Brabander, H F
2007-03-14
Since the 1970s, many analytical methods for the detection of illegal growth promoters, such as thyreostats, anabolics, beta-agonists and corticosteroids have been developed for a wide range of matrices of animal origin, including meat, fat, organ tissue, urine and faeces. The aim of this study was to develop an analytical method for the determination of ng L(-1) levels of estrogens, gestagens, androgens (EGAs) and corticosteroids in aqueous preparations (i.e. drinking water, drinking water supplements), commercially available on the 'black' market. For this, extraction was performed with Bakerbond C18 speedisk, a technique commonly used in environmental analysis. After fractionation, four fractions were collected using a methanol:water gradient program. Gas chromatography coupled to electron impact multiple mass spectrometry (GC-EI-MS2) screening for the EGAs was carried out on the derivatized extracts. For the detection of corticosteroids, gas chromatography coupled to negative chemical ionization mass spectrometry (GC-NCI-MS) was used after oxidation of the extracts. Confirmation was done by liquid chromatography coupled to electrospray ionization multiple mass spectrometry (LC-ESI-MS2). The combined use of GC and LC coupled to MS enabled the identification and quantification of anabolics and corticosteroids at the low ng L(-1) level. This study demonstrated the occurrence of both androgens and corticosteroids in different commercial aqueous samples.
NASA Astrophysics Data System (ADS)
Tritzant-Martinez, Yalina; Zeng, Tao; Broom, Aron; Meiering, Elizabeth; Le Roy, Robert J.; Roy, Pierre-Nicholas
2013-06-01
We investigate the analytical representation of potentials of mean force (pmf) using the Morse/long-range (MLR) potential approach. The MLR method had previously been used to represent potential energy surfaces, and we assess its validity for representing free-energies. The advantage of the approach is that the potential of mean force data only needs to be calculated in the short to medium range region of the reaction coordinate while the long range can be handled analytically. This can result in significant savings in terms of computational effort since one does not need to cover the whole range of the reaction coordinate during simulations. The water dimer with rigid monomers whose interactions are described by the commonly used TIP4P model [W. Jorgensen and J. Madura, Mol. Phys. 56, 1381 (1985)], 10.1080/00268978500103111 is used as a test case. We first calculate an "exact" pmf using direct Monte Carlo (MC) integration and term such a calculation as our gold standard (GS). Second, we compare this GS with several MLR fits to the GS to test the validity of the fitting procedure. We then obtain the water dimer pmf using metadynamics simulations in a limited range of the reaction coordinate and show how the MLR treatment allows the accurate generation of the full pmf. We finally calculate the transition state theory rate constant for the water dimer dissociation process using the GS, the GS MLR fits, and the metadynamics MLR fits. Our approach can yield a compact, smooth, and accurate analytical representation of pmf data with reduced computational cost.
Rotational Energies in Various Torsional Levels of CH_2DOH
NASA Astrophysics Data System (ADS)
Coudert, L. H.; Hilali, A. El; Margulès, L.; Motiyenko, R. A.; Klee, S.
2012-06-01
Using an approach accounting for the hindered internal rotation of a monodeuterated methyl group, an analysis of the torsional spectrum of the monodeuterated species of methanol CH_2DOH has been carried out recently and led to the assignment of 76 torsional subbands in its microwave, FIR, and IR spectra. Although this approach also allowed us to account for subband centers, the rotational structure of the torsional subbands is not well understood yet. In this paper, we will deal with the rotational energies of CH_2DOH. Analyses of the rotational structure of the available subbands^b have been performed using the polynomial-type expansion introduced in the case of the normal species of methanol. For each subband, FIR or IR transitions and a-type microwave lines, within the lower torsional level, were fitted. The frequencies of the latters were taken from previous investigations or from new measurements carried out from 50 to 950 GHz with the submillimeterwave solid state spectrometer in Lille. Subbands involving lower levels with v_t=0 and K ≥ 3 could be satisfactorily analyzed. For levels characterized by lower K-values, the expansion fails. In the case of the K=1, v_t=1 level, the frequencies of a-type microwave transitions involving the lower member of the K-type doublet cannot be well reproduced. For K=0 levels with v_t=1 and 2, a large number of terms is needed in the expansion. We will try to understand why the rotational energies of these levels cannot be reproduced. The results of the analyses will be compared to those obtained with a global approach based on the rotation-torsion Hamiltonian of the molecule. [2] El Hilali, Coudert, Konov, and Klee, J. Chem. Phys. 135 (2011) 194309. [3] Ioli, Moruzzi, Riminucci, Strumia, Moraes, Winnewisser, and Winnewisser, J. Mol. Spec. 171 (1995) 130. [4] Quade and Suenram, J. Chem. Phys. 73 (1980) 1127; and Su and Quade, J. Mol. Spec. 134 (1989) 290. [5] Lauvergnat, Coudert, Klee, and Smirnov, J. Mol. Spec. 256 (2009
Sommerfeld, Thomas; Melugin, Joshua B; Hamal, Prakash; Ehara, Masahiro
2017-06-13
The energy of a metastable state can be computed by adding an artificial stabilizing potential to the Hamiltonian, increasing the stabilization until the metastable state is turned into a bound one, and then further increasing the stabilization until enough bound-state data have been collected so that these can be extrapolated back to vanishing stabilization. The lifetime of the metastable state can be obtained from the same data, but only if the extrapolation is performed by analytic continuation. This extrapolation method is called analytic continuation of the coupling constant (ACCC). Here we introduce preconditioning schemes for two of the three established extrapolation algorithms and critically compare results from all three extrapolation schemes in a variety of situations: As examples for resonance states serve the π* temporary anions of ethylene and formaldehyde as well as a model potential, which provides a case where input data with full numeric precision are available. In the data collection step, three different stabilizing potentials are employed, a Coulomb potential, a short-range Coulomb potential, and a soft-box Voronoi potential. Effects of different orders of the extrapolating Padé approximant are investigated, and last, the energy range of input data for the extrapolation is studied. Moreover, all ACCC results are compared to resonance parameters that have been independently obtained with the same theoretical method, but with a different continuum approach-complex scaling for the model and complex absorbing potentials for the temporary anions.
LeClair, Robert J.; Wang Yinkun; Zhao Peiying; Boileau, Michel; Wang, Lilie; Fleurot, Fabrice
2006-05-15
A CdZnTe detector (CZTD) can be very useful for measuring diagnostic x-ray spectra. The semiconductor detector does, however, exhibit poor hole transport properties and fluorescence generation upon atomic de-excitations. This article describes an analytic model to characterize these two phenomena that occur when a CZTD is exposed to diagnostic x rays. The analytical detector response functions compare well with those obtained via Monte Carlo calculations. The response functions were applied to 50, 80, and 110 kV x-ray spectra. Two 50 kV spectra were measured; one with no filtration and the other with 1.35 mm Al filtration. The unfiltered spectrum was numerically filtered with 1.35 mm of Al in order to see whether the recovered spectrum resembled the filtered spectrum actually measured. A deviation curve was obtained by subtracting one curve from the other on an energy bin by bin basis. The deviation pattern fluctuated around the zero line when corrections were applied to both spectra. Significant deviations from zero towards the lower energies were observed when the uncorrected spectra were used. Beside visual observations, the exposure obtained using the numerically attenuated unfiltered beam was compared to the exposure calculated with the actual filtered beam. The percent differences were 0.8% when corrections were applied and 25% for no corrections. The model can be used to correct diagnostic x-ray spectra measured with a CdZnTe detector.
NASA Astrophysics Data System (ADS)
Alazmi, S.; Xu, Y.; Daqaq, M. F.
2016-07-01
When a container carrying a magnetized ferrofluid is subjected to external mechanical stimuli, the sloshing motion of the magnetized ferrofluid generates a time-varying magnetic flux, which can be used to induce an electromotive force in a coil placed adjacent to the container. This process generates an electric current in the coil, and therewith, can be used to transduce external vibrations into electric energy. In this article, we develop a nonlinear analytical model, which governs the electro-magneto-hydrodynamics of an electromagnetic ferrofluid-based vibratory energy harvester. Using perturbation methods, we obtain an approximate analytical solution of the model for a case involving primary resonance excitation of the first mode and a two-to-one internal resonance between the first two modes. This occurs when the external excitation is harmonic with a frequency close to the fundamental sloshing frequency and when the second modal frequency is nearly twice the first modal frequency. Theoretical results are compared to experimental findings illustrating very good qualitative agreement.
NASA Astrophysics Data System (ADS)
Maia, Natan Zambroni; Calliari, Lauro Julio; Nicolodi, João Luiz
2016-08-01
Sea level oscillations are a result of continuous astronomic, oceanographic, and atmospheric interactions on different time and intensity scales. Thus, the collective action of forcing factors such as tide, wind, atmospheric pressure, and wave action may lead to elevated sea levels during cyclone events over the continental shelf, abruptly impacting adjacent coasts. The objective of this study is to evaluate the potential risks of sea level rise and coastal flooding associated with the passage of cyclones in southern Brazil. An analytical model was developed based on extreme storm events from 1997 to 2008. The model identifies the impact of each forcing factor during temporary sea level rise. Through the development of a digital terrain model, it was possible to identify the areas most vulnerable to flooding by superimposing the terrain model onto calculated sea levels. During storm events, sea level elevations ranged from 2 to 5 m and show wind as the major forcing factor, followed by swells waves, astronomical tide and finally atmospheric pressure.
Energy deposition study of low-energy cosmic radiation at sea level
NASA Astrophysics Data System (ADS)
Wijesinghe, Pushpa
In this dissertation work, a computer simulation model based on the Geant4 simulation package has been designed and developed to study the energy deposition and track structures of cosmic muons and their secondary electrons in tissue-like materials. The particle interactions in a cubic water volume were first simulated. To analyze the energy deposition and tracks in small structures, with the intention of studying the energy localization in nanometric structures such as DNA, the chamber was sliced in three dimentions. Validation studies have been performed by comparing the results with experimental, theoretical, and other simulation results to test the accuracy of the simulation model. A human body phantom in sea-level muon environment was modeled to measure the yearly dose to a human from cosmic muons. The yearly dose in this phantom is about 22 millirems. This is close to the accepted value for the yearly dose from cosmic radiation at sea level. Shielding cosmic muons with a concrete slab from 0 to 2 meters increased the dose received by the body. This dissertation presents an extensive study on the interactions of secondary electrons created by muons in water. Index words. Radiation Dosimetry Simulation, Track Structures, Sea-Level muon Flux, Energy Deposition
NASA Technical Reports Server (NTRS)
King, H. F.; Komornicki, A.
1986-01-01
Formulas are presented relating Taylor series expansion coefficients of three functions of several variables, the energy of the trial wave function (W), the energy computed using the optimized variational wave function (E), and the response function (lambda), under certain conditions. Partial derivatives of lambda are obtained through solution of a recursive system of linear equations, and solution through order n yields derivatives of E through order 2n + 1, extending Puley's application of Wigner's 2n + 1 rule to partial derivatives in couple perturbation theory. An examination of numerical accuracy shows that the usual two-term second derivative formula is less stable than an alternative four-term formula, and that previous claims that energy derivatives are stationary properties of the wave function are fallacious. The results have application to quantum theoretical methods for the computation of derivative properties such as infrared frequencies and intensities.
NASA Technical Reports Server (NTRS)
King, H. F.; Komornicki, A.
1986-01-01
Formulas are presented relating Taylor series expansion coefficients of three functions of several variables, the energy of the trial wave function (W), the energy computed using the optimized variational wave function (E), and the response function (lambda), under certain conditions. Partial derivatives of lambda are obtained through solution of a recursive system of linear equations, and solution through order n yields derivatives of E through order 2n + 1, extending Puley's application of Wigner's 2n + 1 rule to partial derivatives in couple perturbation theory. An examination of numerical accuracy shows that the usual two-term second derivative formula is less stable than an alternative four-term formula, and that previous claims that energy derivatives are stationary properties of the wave function are fallacious. The results have application to quantum theoretical methods for the computation of derivative properties such as infrared frequencies and intensities.
NASA Technical Reports Server (NTRS)
Bieniek, Ronald J.
1996-01-01
Collision-induced transitions can significantly affect molecular vibrational-rotational populations and energy transfer in atmospheres and gaseous systems. This, in turn. can strongly influence convective heat transfer through dissociation and recombination of diatomics. and radiative heat transfer due to strong vibrational coupling. It is necessary to know state-to-state rates to predict engine performance and aerothermodynamic behavior of hypersonic flows, to analyze diagnostic radiative data obtained from experimental test facilities, and to design heat shields and other thermal protective systems. Furthermore, transfer rates between vibrational and translational modes can strongly influence energy flow in various 'disturbed' environments, particularly where the vibrational and translational temperatures are not equilibrated.
NASA Technical Reports Server (NTRS)
Bieniek, Ronald J.
1996-01-01
Collision-induced transitions can significantly affect molecular vibrational-rotational populations and energy transfer in atmospheres and gaseous systems. This, in turn. can strongly influence convective heat transfer through dissociation and recombination of diatomics. and radiative heat transfer due to strong vibrational coupling. It is necessary to know state-to-state rates to predict engine performance and aerothermodynamic behavior of hypersonic flows, to analyze diagnostic radiative data obtained from experimental test facilities, and to design heat shields and other thermal protective systems. Furthermore, transfer rates between vibrational and translational modes can strongly influence energy flow in various 'disturbed' environments, particularly where the vibrational and translational temperatures are not equilibrated.
Identifying Energy-Efficient Concurrency Levels using Machine Learning
Curtis-Maury, M; Singh, K; Blagojevic, F; Nikolopoulos, D S; de Supinski, B R; Schulz, M; McKee, S A
2007-07-23
Multicore microprocessors have been largely motivated by the diminishing returns in performance and the increased power consumption of single-threaded ILP microprocessors. With the industry already shifting from multicore to many-core microprocessors, software developers must extract more thread-level parallelism from applications. Unfortunately, low power-efficiency and diminishing returns in performance remain major obstacles with many cores. Poor interaction between software and hardware, and bottlenecks in shared hardware structures often prevent scaling to many cores, even in applications where a high degree of parallelism is potentially available. In some cases, throwing additional cores at a problem may actually harm performance and increase power consumption. Better use of otherwise limitedly beneficial cores by software components such as hypervisors and operating systems can improve system-wide performance and reliability, even in cases where power consumption is not a main concern. In response to these observations, we evaluate an approach to throttle concurrency in parallel programs dynamically. We throttle concurrency to levels with higher predicted efficiency from both performance and energy standpoints, and we do so via machine learning, specifically artificial neural networks (ANNs). One advantage of using ANNs over similar techniques previously explored is that the training phase is greatly simplified, thereby reducing the burden on the end user. Using machine learning in the context of concurrency throttling is novel. We show that ANNs are effective for identifying energy-efficient concurrency levels in multithreaded scientific applications, and we do so using physical experimentation on a state-of-the-art quad-core Xeon platform.
Shibamoto, T
2006-04-11
Analysis of trace levels of reactive carbonyl compounds (RCCs), including formaldehyde, acetaldehyde, acrolein, malonaldehyde, glyoxal, and methyl glyoxal, is extremely difficult because they are highly reactive, water soluble, and volatile. Determination of these RCCs in trace levels is important because they are major products of lipid peroxidation, which is strongly associated with various diseases such as cancer, Alzheimer's disease, aging, and atherosclerosis. This review covers the development and application of various derivatives for RCC analysis. Among the many derivatives which have been prepared, cysteamine derivatives for formaldehyde and acetaldehyde; N-hydrazine derivatives for acrolein, 4-hydroxy-2-nonenal, and malonaldeyde; and o-phenylene diamine derivatives for glyoxal and methyl glyoxal were selected for extended discussion. The application of advanced instruments, including gas chromatograph with nitrogen-phosphorus detector (GC/NPD), mass spectrometer (MS), high performance liquid chromatograph (HPLC), GC/MS, and LC/MS, to the determination of trace RCCs in various oxidized lipid samples, including fatty acids, skin lipids, beef fats, blood plasma, whole blood, and liver homogenates, is also discussed.
Formation energies and energy levels of deep defects in narrow gap semiconductors
Patterson, J.D.; Li, W.
1996-12-31
The authors use a Green`s function technique for deep defect energy level calculations in mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS). The formation energy is calculated from the difference between the total binding energy with an impurity cluster and with a perfect cluster. These alloys are among those that have been experimentally grown in microgravity aboard the Space Shuttle. To evaluate the quality of these crystals, it is necessary to characterize them, and one important aspect of this characterization is the study of deep defects which can limit carrier lifetime. Relaxation effects are calculated with molecular dynamics. The resulting energy shift can be greater for the interstitial case than the substitutional one. Relaxation in vacancies is also considered. The charged state energy shift (as computed by a modified Haldane-Anderson model) can be twice that caused by relaxation. However, different charged states for vacancies had little effect on the formation energy. For all cases the authors considered the concentration of Cd or Zn in the range appropriate for a band gap of 0.1 eV. The emphasis of their calculation is on chemical trends. Only limited comparison to experiment and other calculations is possible, but what there is supports the statement that their results are at least of the right order of magnitude.
Energy Levels and Co-evolution of Product Innovation in Supply Chain Clusters
NASA Astrophysics Data System (ADS)
Ji, Guojun
In the last decade supply chain clusters phenomenon has emerged as a new approach in product innovation studies. This article makes three contributions to the approach by addressing some open issues. The first contribution is to explicitly incorporate the energy levels in the analysis. Hence, the unit of analysis is widened from sectoral systems of innovation to socio-technical systems. Hence, the unit of analysis is widened from sectoral systems of innovation to socio-technical systems. The second contribution is to suggest an analytical distinction between different evolution method, actors involved in them, and the institutions which guide actor's perceptions and activities. Thirdly, the article opens up the black box of institutions, making them an integral part of supply chain. The article provides a coherent conceptual multi-level perspective, using insights from sociology, institutional theory and innovation studies. The perspective is particularly useful to analyze long-term dynamics supply chain clusters phenomenon, shifts from one energy level to another and the co-evolution of product innovation.
Kerr, L N; Boivin, W S; Boyd, S M; Coletta, J N
2001-01-01
An energy-efficient lighting retrofit at the Food and Drug Administration (FDA) Winchester Engineering and Analytical Center (WEAC) presented the opportunity to measure the electromagnetic (EM) environments in several rooms before and after changing the fluorescent lighting systems and to compare the changes in EM fields with the proposed standard EM immunity levels. Three rooms, representing the types of work areas in the laboratory, were selected and measured before and after the lighting changeover. Electric and magnetic field measurements were taken in the extremely low frequency (ELF), very low frequency (VLF), and radio frequency (RF) ranges of the EM spectrum. In 2 rooms, ELF electric fields were reduced and VLF and RF electric fields were increased as a result of the changeover to high-frequency fixtures. A third room received low-frequency, energy-efficient fixtures during this changeover, and this change resulted in only a slight increase of the ELF electric fields. The ELF magnetic fields were greatly reduced in 2 but only slightly reduced in the third room. No significant change was seen in VLF or RF magnetic fields for any of these rooms. Some field-strength measurements exceeded the proposed immunity levels recommended in the draft International Electrotechnical Commission standard IEC 60601-1-2 (rev. 2). The data show that increasing the separation distance from the fluorescent light fixtures greatly reduces the field-strength levels, limiting the potential for EM interference.
Saturation of Energy Levels in Analytical Atomic Fluorescence Spectrometry. II. Experimental.
1981-01-30
REPORT NUNSER01 I.Experimentald 7. TTH.ORi. - I.- . CONTROACT On GRANT NSIER(s) Dorys Rojas deOlivares aW Gary M./Hieftje / N14-76-C-0838 CIS. PERFORMING...EXPERIMENTAL by Dorys Rojas de Olivares and Gary M. Hieftje Prepared for Publication Accession For WTIS GRA&I in DTIC TAB Unannozincod F...necessary. ACKNOWLEDGEMlENT wrVVwVVA VVVV\\IVV I Taken in part from the Ph.D. thesis of D. Rojas de Olivares, Indiana University, 1976. Supported in part
An analytical study of a lead-acid flow battery as an energy storage system
NASA Astrophysics Data System (ADS)
Bates, Alex; Mukerjee, Santanu; Lee, Sang C.; Lee, Dong-Ha; Park, Sam
2014-03-01
The most important issue with our current clean energy technology is the dependence on environmental conditions to produce power. To solve this problem a wide range of energy storage devices are being explored for grid-scale energy storage including soluble lead-acid flow batteries. Flow batteries offer a unique solution to grid-scale energy storage because of their electrolyte tanks which allow easy scaling of storage capacity. This study seeks to further understand the mechanisms of a soluble lead acid flow battery using simulations. The effects of varies changes to operating conditions and the system configuration can be explored through simulations. The simulations preformed are 2D and include the positive electrode, negative electrode, and the flow space between them. Simulations presented in this study show Pb(II) surface concentration, external electric potential, and PbO/PbO2 surface concentration on the positive electrode. Simulations have shown increasing cell temperature can increase external electric potential by as much as 0.2 V during charge. Simulations have also shown electrolyte velocity is an important aspect when investigating lead deposition onto the electrodes. Experimental work was performed to validate simulation results of current density and voltage. Good correlation was found between experimental work and simulation results.
Zonal winds near Venus' cloud top level - An analytic model of the equatorial wind speed
NASA Technical Reports Server (NTRS)
Leovy, Conway B.
1987-01-01
A consequence of the presently hypothesized maintenance of the equatorial wind speed near the cloud top level of Venus by a balance between the semidiurnal tide's pumping and the Hadley circulation's vertical advection (both integrated across the thermal driving region) is that the maximum equatorial zonal wind speed is proportional to the product of the buoyancy frequency and the magnitude of the driving region's thickness. The proportionality constant is characterized as a weakly increasing function of the heating rate, and a decreasing function of the product of an inverse length, expressing the mean zonal wind shear, and the driving region thickness. For the class of solutions thus treated, there is a threshold heating rate value below which no equilibrium satisfies the prescribed balance.
Zeng, Qiao; Liang, WanZhen
2015-10-07
The time-dependent density functional theory (TDDFT) has become the most popular method to calculate the electronic excitation energies, describe the excited-state properties, and perform the excited-state geometric optimization of medium and large-size molecules due to the implementation of analytic excited-state energy gradient and Hessian in many electronic structure software packages. To describe the molecules in condensed phase, one usually adopts the computationally efficient hybrid Quantum Mechanics/Molecular Mechanics (QM/MM) models. Here, we extend our previous work on the energy gradient of TDDFT/MM excited state to account for the mutual polarization effects between QM and MM regions, which is believed to hold a crucial position in the potential energy surface of molecular systems when the photoexcitation-induced charge rearrangement in the QM region is drastic. The implementation of a simple polarizable TDDFT/MM (TDDFT/MMpol) model in Q-Chem/CHARMM interface with both the linear response and the state-specific features has been realized. Several benchmark tests and preliminary applications are exhibited to confirm our implementation and assess the effects of different treatment of environmental polarization on the excited-state properties, and the efficiency of parallel implementation is demonstrated as well.
Zou, Wenli; Filatov, Michael; Cremer, Dieter
2015-06-07
The analytical gradient for the two-component Normalized Elimination of the Small Component (2c-NESC) method is presented. The 2c-NESC is a Dirac-exact method that employs the exact two-component one-electron Hamiltonian and thus leads to exact Dirac spin-orbit (SO) splittings for one-electron atoms. For many-electron atoms and molecules, the effect of the two-electron SO interaction is modeled by a screened nucleus potential using effective nuclear charges as proposed by Boettger [Phys. Rev. B 62, 7809 (2000)]. The effect of spin-orbit coupling (SOC) on molecular geometries is analyzed utilizing the properties of the frontier orbitals and calculated SO couplings. It is shown that bond lengths can either be lengthened or shortened under the impact of SOC where in the first case the influence of low lying excited states with occupied antibonding orbitals plays a role and in the second case the jj-coupling between occupied antibonding and unoccupied bonding orbitals dominates. In general, the effect of SOC on bond lengths is relatively small (≤5% of the scalar relativistic changes in the bond length). However, large effects are found for van der Waals complexes Hg{sub 2} and Cn{sub 2}, which are due to the admixture of more bonding character to the highest occupied spinors.
Wei, Weigang; Van Renterghem, Timothy; Botteldooren, Dick
2015-11-01
Accurate and efficient prediction of the sound field in shadow zones behind obstacles is a challenging task but essential to produce urban noise maps. A simplified method is presented to predict sound levels at shielded urban locations, including multi-edge diffraction over successive buildings and multiple reflections between parallel façades. The model is essentially based on Pierce's diffraction theory, where the Fresnel Integral is approximated by trigonometric functions for efficient evaluation, and parameterized for urban environments. The model has been validated for idealized urban configurations by comparing to the results of Pierce's theory and a full-wave numerical method. In case of multi-edge diffraction over buildings in absence of a source or receiver canyon, deviations from the full-wave simulations are smaller than 2 dB for the octave bands with central frequencies ranging from 125 to 1000 Hz. However, larger errors are made when receivers are close to the extension line from the diffraction edge closest to the receiver. In case of combining the simplified multi-edge diffraction model with an efficient approach for including the series of mirror sources and mirror receivers, based on the Hurwitz-Lerch transcendent, this same accuracy is obtained.
Laplacian-level density functionals for the kinetic energy density and exchange-correlation energy
NASA Astrophysics Data System (ADS)
Perdew, John P.; Constantin, Lucian A.
2007-04-01
We construct a Laplacian-level meta-generalized-gradient-approximation (meta-GGA) for the noninteracting (Kohn-Sham orbital) positive kinetic energy density τ of an electronic ground state of density n . This meta-GGA is designed to recover the fourth-order gradient expansion τGE4 in the appropriate slowly varying limit and the von Weizsäcker expression τW=∣∇n∣2/(8n) in the rapidly varying limit. It is constrained to satisfy the rigorous lower bound τW(r)⩽τ(r) . Our meta-GGA is typically a strong improvement over the gradient expansion of τ for atoms, spherical jellium clusters, jellium surfaces, the Airy gas, Hooke’s atom, one-electron Gaussian density, quasi-two-dimensional electron gas, and nonuniformly scaled hydrogen atom. We also construct a Laplacian-level meta-GGA for exchange and correlation by employing our approximate τ in the Tao-Perdew-Staroverov-Scuseria (TPSS) meta-GGA density functional. The Laplacian-level TPSS gives almost the same exchange-correlation enhancement factors and energies as the full TPSS, suggesting that τ and ∇2n carry about the same information beyond that carried by n and ∇n . Our kinetic energy density integrates to an orbital-free kinetic energy functional that is about as accurate as the fourth-order gradient expansion for many real densities (with noticeable improvement in molecular atomization energies), but considerably more accurate for rapidly varying ones.
Melaina, Marc; Saur, Genevieve; Ramsden, Todd; Eichman, Joshua
2015-05-28
This presentation summarizes NREL's hydrogen and fuel cell analysis work in three areas: resource potential, greenhouse gas emissions and cost of delivered energy, and influence of auxiliary revenue streams. NREL's hydrogen and fuel cell analysis projects focus on low-carbon and economic transportation and stationary fuel cell applications. Analysis tools developed by the lab provide insight into the degree to which bridging markets can strengthen the business case for fuel cell applications.
NASA Astrophysics Data System (ADS)
Yuan, H. Z.; Chen, Z.; Shu, C.; Wang, Y.; Niu, X. D.; Shu, S.
2017-09-01
In this paper, a free energy-based surface tension force (FESF) model is presented for accurately resolving the surface tension force in numerical simulation of multiphase flows by the level set method. By using the analytical form of order parameter along the normal direction to the interface in the phase-field method and the free energy principle, FESF model offers an explicit and analytical formulation for the surface tension force. The only variable in this formulation is the normal distance to the interface, which can be substituted by the distance function solved by the level set method. On one hand, as compared to conventional continuum surface force (CSF) model in the level set method, FESF model introduces no regularized delta function, due to which it suffers less from numerical diffusions and performs better in mass conservation. On the other hand, as compared to the phase field surface tension force (PFSF) model, the evaluation of surface tension force in FESF model is based on an analytical approach rather than numerical approximations of spatial derivatives. Therefore, better numerical stability and higher accuracy can be expected. Various numerical examples are tested to validate the robustness of the proposed FESF model. It turns out that FESF model performs better than CSF model and PFSF model in terms of accuracy, stability, convergence speed and mass conservation. It is also shown in numerical tests that FESF model can effectively simulate problems with high density/viscosity ratio, high Reynolds number and severe topological interfacial changes.
NASA Astrophysics Data System (ADS)
Le Roy, Robert J.; Walji, Sadru; Sentjens, Katherine
2013-06-01
Alkali hydride diatomic molecules have long been the object of spectroscopic studies. However, their small reduced mass makes them species for which the conventional semiclassical-based methods of analysis tend to have the largest errors. To date, the only quantum-mechanically accurate direct-potential-fit (DPF) analysis for one of these molecules was the one for LiH reported by Coxon and Dickinson. The present paper extends this level of analysis to NaH, and reports a DPF analysis of all available spectroscopic data for the A ^1Σ^+-X ^1Σ^+ system of NaH which yields analytic potential energy functions for these two states that account for those data (on average) to within the experimental uncertainties. W.C. Stwalley, W.T. Zemke and S.C. Yang, J. Phys. Chem. Ref. Data {20}, 153-187 (1991). J.A. Coxon and C.S. Dickinson, J. Chem. Phys. {121}, 8378 (2004).
Delcey, Mickaël G.; Freitag, Leon; González, Leticia; Pedersen, Thomas Bondo; Aquilante, Francesco; Lindh, Roland
2014-05-07
We present a formulation of analytical energy gradients at the complete active space self-consistent field (CASSCF) level of theory employing density fitting (DF) techniques to enable efficient geometry optimizations of large systems. As an example, the ground and lowest triplet state geometries of a ruthenium nitrosyl complex are computed at the DF-CASSCF level of theory and compared with structures obtained from density functional theory (DFT) using the B3LYP, BP86, and M06L functionals. The average deviation of all bond lengths compared to the crystal structure is 0.042 Å at the DF-CASSCF level of theory, which is slightly larger but still comparable with the deviations obtained by the tested DFT functionals, e.g., 0.032 Å with M06L. Specifically, the root-mean-square deviation between the DF-CASSCF and best DFT coordinates, delivered by BP86, is only 0.08 Å for S{sub 0} and 0.11 Å for T{sub 1}, indicating that the geometries are very similar. While keeping the mean energy gradient errors below 0.25%, the DF technique results in a 13-fold speedup compared to the conventional CASSCF geometry optimization algorithm. Additionally, we assess the singlet-triplet energy vertical and adiabatic differences with multiconfigurational second-order perturbation theory (CASPT2) using the DF-CASSCF and DFT optimized geometries. It is found that the vertical CASPT2 energies are relatively similar regardless of the geometry employed whereas the adiabatic singlet-triplet gaps are more sensitive to the chosen triplet geometry.
Delcey, Mickaël G; Freitag, Leon; Pedersen, Thomas Bondo; Aquilante, Francesco; Lindh, Roland; González, Leticia
2014-05-07
We present a formulation of analytical energy gradients at the complete active space self-consistent field (CASSCF) level of theory employing density fitting (DF) techniques to enable efficient geometry optimizations of large systems. As an example, the ground and lowest triplet state geometries of a ruthenium nitrosyl complex are computed at the DF-CASSCF level of theory and compared with structures obtained from density functional theory (DFT) using the B3LYP, BP86, and M06L functionals. The average deviation of all bond lengths compared to the crystal structure is 0.042 Å at the DF-CASSCF level of theory, which is slightly larger but still comparable with the deviations obtained by the tested DFT functionals, e.g., 0.032 Å with M06L. Specifically, the root-mean-square deviation between the DF-CASSCF and best DFT coordinates, delivered by BP86, is only 0.08 Å for S0 and 0.11 Å for T1, indicating that the geometries are very similar. While keeping the mean energy gradient errors below 0.25%, the DF technique results in a 13-fold speedup compared to the conventional CASSCF geometry optimization algorithm. Additionally, we assess the singlet-triplet energy vertical and adiabatic differences with multiconfigurational second-order perturbation theory (CASPT2) using the DF-CASSCF and DFT optimized geometries. It is found that the vertical CASPT2 energies are relatively similar regardless of the geometry employed whereas the adiabatic singlet-triplet gaps are more sensitive to the chosen triplet geometry.
NASA Astrophysics Data System (ADS)
Aghakhani, Amirreza; Basdogan, Ipek; Erturk, Alper
2016-04-01
Plate-like components are widely used in numerous automotive, marine, and aerospace applications where they can be employed as host structures for vibration based energy harvesting. Piezoelectric patch harvesters can be easily attached to these structures to convert the vibrational energy to the electrical energy. Power output investigations of these harvesters require accurate models for energy harvesting performance evaluation and optimization. Equivalent circuit modeling of the cantilever-based vibration energy harvesters for estimation of electrical response has been proposed in recent years. However, equivalent circuit formulation and analytical modeling of multiple piezo-patch energy harvesters integrated to thin plates including nonlinear circuits has not been studied. In this study, equivalent circuit model of multiple parallel piezoelectric patch harvesters together with a resistive load is built in electronic circuit simulation software SPICE and voltage frequency response functions (FRFs) are validated using the analytical distributedparameter model. Analytical formulation of the piezoelectric patches in parallel configuration for the DC voltage output is derived while the patches are connected to a standard AC-DC circuit. The analytic model is based on the equivalent load impedance approach for piezoelectric capacitance and AC-DC circuit elements. The analytic results are validated numerically via SPICE simulations. Finally, DC power outputs of the harvesters are computed and compared with the peak power amplitudes in the AC output case.
Zhang, Bo; Chen, Tianning; Zhao, Yuyuan; Zhang, Weiyong; Zhu, Jian
2012-09-01
On the basis of the work of Wilson et al. [J. Acoust. Soc. Am. 84, 350-359 (1988)], a more exact numerical approach was constructed for predicting the nonlinear sound propagation and absorption properties of rigid porous media at high sound pressure levels. The numerical solution was validated by the experimental results for sintered fibrous porous steel samples and its predictions were compared with the numerical solution of Wilson et al. An approximate analytical solution was further put forward for the normalized surface acoustic admittance of rigid air-saturated porous materials with infinite thickness, based on the wave perturbation method developed by Lambert and McIntosh [J. Acoust. Soc. Am. 88, 1950-1959 (1990)]. Comparisons were made with the numerical results.
Energy transfer and energy level decay processes in Tm{sup 3+}-doped tellurite glass
Gomes, Laercio; Lousteau, Joris; Milanese, Daniel; Scarpignato, Gerardo C.; Jackson, Stuart D.
2012-03-15
The primary excited state decay and energy transfer processes in singly Tm{sup 3+}-doped TeO{sub 2}:ZnO:Bi{sub 2}O{sub 3}:GeO{sub 2} (TZBG) glass relating to the {sup 3}F{sub 4}{yields}{sup 3}H{sub 6}{approx}1.85 {mu}m laser transition have been investigated in detail using time-resolved fluorescence spectroscopy. Selective laser excitation of the {sup 3}H{sub 4} manifold at 794 nm, the {sup 3}H{sub 5} manifold at 1220 nm, and {sup 3}F{sub 4} manifold at 1760 nm has established that the {sup 3}H{sub 5} manifold is entirely quenched by multiphonon relaxation in tellurite glass. The luminescence from the {sup 3}H{sub 4} manifold with an emission peak at 1465 nm suffers strong suppression due to cross relaxation that populates the {sup 3}F{sub 4} level with a near quadratic dependence on the Tm{sup 3+} concentration. The {sup 3}F{sub 4} lifetime becomes longer as the Tm{sup 3+} concentration increases due to energy migration and decreases to 2.92 ms when [Tm{sup 3+}] = 4 mol. % as a result of quasi-resonant energy transfer to free OH{sup -} radicals present in the glass at concentrations between 1 x 10{sup 18} cm{sup -3} and 2 x 10{sup 18} cm{sup -3}. Judd-Ofelt theory in conjunction with absorption measurements were used to obtain the radiative lifetimes and branching ratios of the energy levels located below 25 000 cm{sup -1}. The spectroscopic parameters, the cross relaxation and Tm{sup 3+}({sup 3}F{sub 4}) {yields} OH{sup -} energy transfer rates were used in a numerical model for laser transitions emitting at 2335 nm and 1865 nm.
Bolinger, Mark A; Wiser, Ryan
2008-09-15
For better or worse, natural gas has become the fuel of choice for new power plants being built across the United States. According to the Energy Information Administration (EIA), natural gas-fired units account for nearly 90% of the total generating capacity added in the U.S. between 1999 and 2005 (EIA 2006b), bringing the nationwide market share of gas-fired generation to 19%. Looking ahead over the next decade, the EIA expects this trend to continue, increasing the market share of gas-fired generation to 22% by 2015 (EIA 2007a). Though these numbers are specific to the US, natural gas-fired generation is making similar advances in many other countries as well. A large percentage of the total cost of gas-fired generation is attributable to fuel costs--i.e., natural gas prices. For example, at current spot prices of around $7/MMBtu, fuel costs account for more than 75% of the levelized cost of energy from a new combined cycle gas turbine, and more than 90% of its operating costs (EIA 2007a). Furthermore, given that gas-fired plants are often the marginal supply units that set the market-clearing price for all generators in a competitive wholesale market, there is a direct link between natural gas prices and wholesale electricity prices. In this light, the dramatic increase in natural gas prices since the 1990s should be a cause for ratepayer concern. Figure 1 shows the daily price history of the 'first-nearby' (i.e., closest to expiration) NYMEX natural gas futures contract (black line) at Henry Hub, along with the futures strip (i.e., the full series of futures contracts) from August 22, 2007 (red line). First, nearby prices, which closely track spot prices, have recently been trading within a $7-9/MMBtu range in the United States and, as shown by the futures strip, are expected to remain there through 2012. These price levels are $6/MMBtu higher than the $1-3/MMBtu range seen throughout most of the 1990s, demonstrating significant price escalation for natural
Xie, Wangshen; Song, Lingchun; Truhlar, Donald G.; Gao, Jiali
2008-01-01
A previous article proposed an electronic structure-based polarizable potential, called the explicit polarization (X-POL) potential, to treat many-body polarization and charge delocalization effects in polypeptides. Here, we present a variational version of the X-POL potential, in which the wave function of the entire molecular system is variationally optimized to yield the minimum total electronic energy. This allows the calculation of analytic gradients, a necessity for efficient molecular dynamics simulations. In this paper, the detailed derivations of the Fock matrix and analytic force are presented and discussed. The calculations involve a double self-consistent-field procedure in which the wave function of each fragment is self-consistently optimized in the presence of other fragments, and in addition the polarization of the entire system is self-consistently optimized. The variational X-POL potential has been implemented in the Chemistry at Harvard Molecular Mechanics (CHARMM) package and tested successfully for small model compounds. PMID:18570492
Dynamical image-charge effect in molecular tunnel junctions: Beyond energy level alignment
NASA Astrophysics Data System (ADS)
Jin, Chengjun; Thygesen, Kristian S.
2014-01-01
When an electron tunnels between two metal contacts it temporarily induces an image charge (IC) in the electrodes which acts back on the tunneling electron. It is usually assumed that the IC forms instantaneously such that a static model for the image potential applies. Here we investigate how the finite IC formation time affects charge transport through a molecule suspended between two electrodes. For a single-level model, an analytical treatment shows that the conductance is suppressed by a factor Z2, where Z is the quasiparticle renormalization factor, compared to the static IC approximation. We show that Z can be expressed either in terms of the plasma frequency of the electrode or as the overlap between electrode wave functions corresponding to an empty and filled level, respectively. First-principles GW calculations for benzene-diamine connected to gold electrodes show that the dynamical corrections can reduce the conductance by more than a factor of two when compared to static GW or density functional theory where the molecular energy levels have been shifted to match the exact quasiparticle levels.
Daniels, Vijay John; Harley, Dwight
2017-07-01
Although previous research has compared checklists to rating scales for assessing communication, the purpose of this study was to compare the effect on reliability and sensitivity to level of training of an analytic, a holistic, and a combined analytic-holistic rating scale in assessing communication skills. The University of Alberta Internal Medicine Residency runs OSCEs for postgraduate year (PGY) 1 and 2 residents and another for PGY-4 residents. Communication stations were scored with an analytic scale (empathy, non-verbal skills, verbal skills, and coherence subscales) and a holistic scale. Authors analyzed reliability of individual and combined scales using generalizability theory and evaluated each scale's sensitivity to level of training. For analytic, holistic, and combined scales, 12, 12, and 11 stations respectively yielded a Phi of 0.8 for the PGY-1,2 cohort, and 16, 16, and 14 stations yielded a Phi of 0.8 for the PGY-4 cohort. PGY-4 residents scored higher on the combined scale, the analytic rating scale, and the non-verbal and coherence subscales. A combined analytic-holistic rating scale increased score reliability and was sensitive to level of training. Given increased validity evidence, OSCE developers should consider combining analytic and holistic scales when assessing communication skills. Copyright © 2017 Elsevier B.V. All rights reserved.
ERIC Educational Resources Information Center
Cartwright, Dennis D.; Heikkinen, Michael W.
Reported is a study of the effectiveness of the Energy Environment Simulator (EES) in developing energy awareness and positive attitudes towards energy issues in students at various levels of cognitive development. The EES is a portable computer model of U.S. energy resources, environmental quality and food distribution. Subjects were students…
ARRA-Multi-Level Energy Storage and Controls for Large-Scale Wind Energy Integration
David Wenzhong Gao
2012-09-30
The Project Objective is to design innovative energy storage architecture and associated controls for high wind penetration to increase reliability and market acceptance of wind power. The project goals are to facilitate wind energy integration at different levels by design and control of suitable energy storage systems. The three levels of wind power system are: Balancing Control Center level, Wind Power Plant level, and Wind Power Generator level. Our scopes are to smooth the wind power fluctuation and also ensure adequate battery life. In the new hybrid energy storage system (HESS) design for wind power generation application, the boundary levels of the state of charge of the battery and that of the supercapacitor are used in the control strategy. In the controller, some logic gates are also used to control the operating time durations of the battery. The sizing method is based on the average fluctuation of wind profiles of a specific wind station. The calculated battery size is dependent on the size of the supercapacitor, state of charge of the supercapacitor and battery wear. To accommodate the wind power fluctuation, a hybrid energy storage system (HESS) consisting of battery energy system (BESS) and super-capacitor is adopted in this project. A probability-based power capacity specification approach for the BESS and super-capacitors is proposed. Through this method the capacities of BESS and super-capacitor are properly designed to combine the characteristics of high energy density of BESS and the characteristics of high power density of super-capacitor. It turns out that the super-capacitor within HESS deals with the high power fluctuations, which contributes to the extension of BESS lifetime, and the super-capacitor can handle the peaks in wind power fluctuations without the severe penalty of round trip losses associated with a BESS. The proposed approach has been verified based on the real wind data from an existing wind power plant in Iowa. An
Zhou, Kaining; Feng, Zhongshan; Shen, Jun; Wu, Bing; Luo, Xiaobing; Jiang, Sha; Li, Li; Zhou, Xianju
2016-04-05
High resolution spectra and luminescent lifetimes of 6 europium(III)-cinnamic acid complex {[Eu2L6(DMF)(H2O)]·nDMF·H2O}m (L=cinnamic acid I, 4-methyl-cinnamic acid II, 4-chloro-cinnamic acid III, 4-methoxy-cinnamic acid IV, 4-hydroxy-cinnamic acid V, 4-nitro-cinnamic acid VI; DMF=N, N-dimethylformamide, C3H7NO) were recorded from 8 K to room temperature. The energy levels of Eu(3+) in these 6 complexes are obtained from the spectra analysis. It is found that the energy levels of the central Eu(3+) ions are influenced by the nephelauxetic effect, while the triplet state of ligand is lowered by the p-π conjugation effect of the para-substituted functional groups. The best energy matching between the ligand triplet state and the central ion excited state is found in complex I. While the other complexes show poorer matching because the gap of (5)D0 and triplet state contracts.
NASA Astrophysics Data System (ADS)
Zhou, Kaining; Feng, Zhongshan; Shen, Jun; Wu, Bing; Luo, Xiaobing; Jiang, Sha; Li, Li; Zhou, Xianju
2016-04-01
High resolution spectra and luminescent lifetimes of 6 europium(III)-cinnamic acid complex {[Eu2L6(DMF)(H2O)]·nDMF·H2O}m (L = cinnamic acid I, 4-methyl-cinnamic acid II, 4-chloro-cinnamic acid III, 4-methoxy-cinnamic acid IV, 4-hydroxy-cinnamic acid V, 4-nitro-cinnamic acid VI; DMF = N, N-dimethylformamide, C3H7NO) were recorded from 8 K to room temperature. The energy levels of Eu3 + in these 6 complexes are obtained from the spectra analysis. It is found that the energy levels of the central Eu3 + ions are influenced by the nephelauxetic effect, while the triplet state of ligand is lowered by the p-π conjugation effect of the para-substituted functional groups. The best energy matching between the ligand triplet state and the central ion excited state is found in complex I. While the other complexes show poorer matching because the gap of 5D0 and triplet state contracts.
NASA Astrophysics Data System (ADS)
Chesnaux, R.
2016-04-01
Closed-form analytical solutions for assessing the consequences of sea-level rise on fresh groundwater oceanic island lenses are provided for the cases of both strip and circular islands. Solutions are proposed for directly calculating the change in the thickness of the lens, the changes in volume and the changes in travel time of fresh groundwater within island aquifers. The solutions apply for homogenous aquifers recharged by surface infiltration and discharged by a down-gradient, fixed-head boundary. They also take into account the inland shift of the ocean due to land surface inundation, this shift being determined by the coastal slope of inland aquifers. The solutions are given for two simple island geometries: circular islands and strip islands. Base case examples are presented to illustrate, on one hand, the amplitude of the change of the fresh groundwater lens thickness and the volume depletion of the lens in oceanic island with sea-level rise, and on the other hand, the shortening of time required for groundwater to discharge into the ocean. These consequences can now be quantified and may help decision-makers to anticipate the effects of sea-level rise on fresh groundwater availability in oceanic island aquifers.
Marsolat, F; De Marzi, L; Pouzoulet, F; Mazal, A
2016-01-21
In proton therapy, the relative biological effectiveness (RBE) depends on various types of parameters such as linear energy transfer (LET). An analytical model for LET calculation exists (Wilkens' model), but secondary particles are not included in this model. In the present study, we propose a correction factor, L sec, for Wilkens' model in order to take into account the LET contributions of certain secondary particles. This study includes secondary protons and deuterons, since the effects of these two types of particles can be described by the same RBE-LET relationship. L sec was evaluated by Monte Carlo (MC) simulations using the GATE/GEANT4 platform and was defined by the ratio of the LET d distributions of all protons and deuterons and only primary protons. This method was applied to the innovative Pencil Beam Scanning (PBS) delivery systems and L sec was evaluated along the beam axis. This correction factor indicates the high contribution of secondary particles in the entrance region, with L sec values higher than 1.6 for a 220 MeV clinical pencil beam. MC simulations showed the impact of pencil beam parameters, such as mean initial energy, spot size, and depth in water, on L sec. The variation of L sec with these different parameters was integrated in a polynomial function of the L sec factor in order to obtain a model universally applicable to all PBS delivery systems. The validity of this correction factor applied to Wilkens' model was verified along the beam axis of various pencil beams in comparison with MC simulations. A good agreement was obtained between the corrected analytical model and the MC calculations, with mean-LET deviations along the beam axis less than 0.05 keV μm(-1). These results demonstrate the efficacy of our new correction of the existing LET model in order to take into account secondary protons and deuterons along the pencil beam axis.
Ab initio potential energy surface and vibration-rotation energy levels of beryllium monohydroxide.
Koput, Jacek
2017-01-05
The accurate potential energy surface of beryllium monohydroxide, BeOH, in its ground electronic state X 2A' has been determined from ab initio calculations using the coupled-cluster approach in conjunction with the correlation-consistent core-valence basis sets up to septuple-zeta quality. The higher-order electron correlation, scalar relativistic, and adiabatic effects were taken into account. The BeOH molecule was confirmed to be bent at equilibrium, with the BeOH angle of 141.2° and the barrier to linearity of 129 cm(-1) . The vibration-rotation energy levels of the BeOH and BeOD isotopologues were predicted using a variational approach and compared with recent experimental data. The results can be useful in a further analysis of high-resolution vibration-rotation spectra of these interesting species. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Ab initio potential energy surface and vibration-rotation energy levels of sulfur dioxide.
Koput, Jacek
2017-05-05
An accurate potential energy surface of sulfur dioxide, SO2 , in its ground electronic state X∼ 1A1 has been determined from ab initio calculations using the coupled-cluster approach in conjunction with the correlation-consistent basis sets up to septuple-zeta quality. The results obtained with the conventional and explicitly correlated coupled-cluster methods are compared. The role of the core-electron correlation, higher-order valence-electron correlation, scalar relativistic, and adiabatic effects in determining the structure and dynamics of the SO2 molecule is discussed. The vibration-rotation energy levels of the (32) SO2 and (34) SO2 isotopologues were predicted using a variational approach. It was shown that the inclusion of the aforementioned effects was mandatory to attain the "spectroscopic" accuracy. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Okeechobee County Energy Education Activities--Middle School Level.
ERIC Educational Resources Information Center
Allen, Rodney F., Ed.
Over 60 energy education activities related to mathematics, science, social studies, and English comprise this manual for middle school teachers. Included are issues for discussion, puzzles, science investigations, story writing exercises, and energy cost calculation problems. Among the topics covered in these lessons are energy consumption…
Superconductive magnetic energy storage for electric utility load leveling
Eyssa, Y.M.; Boom, R.W.; Hartwig, K.T.; McIntosh, G.E.; Van Sciver, S.W.; Bischke, R.F.
1981-08-01
An assessment of the value of superconductive magnetic energy storage (SMES) for electric utilities is given, with the Wisconsin utility electric power system as an example. It is shown that SMES is superior to all othe forms of energy storage in regard to efficiency of storage, speed for response and amount of energy which can be economically cycled through storage. 7 refs.
Oxygen consumption and energy expenditure of level versus downhill running.
Robergs, R A; Wagner, D R; Skemp, K M
1997-09-01
The purpose of this study was to assess and compare submaximal oxygen consumption (VO2) and energy expenditure (kJ) while running at 0, -1.8, -3.6, and -5.4% grades for three individually selected running speeds (9.4 + 0.79, 10.3 + 0.74, 11.3 + 0.73 km.h-1). Subjects completed the four grade conditions in random order via a modified Latin squares design at three self-selected submaximal running speeds for each condition. Thirteen (5 females and 8 males) recreational (< 35 km.wk-1) runners (age: 27.7 +/- 4.3 yrs) volunteered for the study. Two-way repeated measures ANOVA (Grade x Speed) was used to analyze steady-state VO2 and kJ expenditure. Stepwise linear multiple regression was used to develop an equation for predicting VO2 for running at recreational speeds on moderately negative grades. VO2 and kJ mean values were significantly different between all speed and % grade comparisons. Compared to level grade, the average reductions in VO2 and kJ expenditure ranged from approximately 9% at a grade of -1.8% to 22% at a grade of -5.4%. The relationship between VO2 and % grade for each running speed was linear. For a given speed, running at a modest negative grade can significantly decrease VO2 and kJ expenditure compared to level running. The following regression equation can be used to estimate VO2 (ml.kg-1.min-1) for running at recreational speeds on slight downhills: VO2 = 6.8192 + 0.1313 (speed in m.min-1) + 1.2367 (% grade).
Mashouf, Shahram; Lechtman, Eli; Beaulieu, Luc; Verhaegen, Frank; Keller, Brian M; Ravi, Ananth; Pignol, Jean-Philippe
2013-09-21
The American Association of Physicists in Medicine Task Group No. 43 (AAPM TG-43) formalism is the standard for seeds brachytherapy dose calculation. But for breast seed implants, Monte Carlo simulations reveal large errors due to tissue heterogeneity. Since TG-43 includes several factors to account for source geometry, anisotropy and strength, we propose an additional correction factor, called the inhomogeneity correction factor (ICF), accounting for tissue heterogeneity for Pd-103 brachytherapy. This correction factor is calculated as a function of the media linear attenuation coefficient and mass energy absorption coefficient, and it is independent of the source internal structure. Ultimately the dose in heterogeneous media can be calculated as a product of dose in water as calculated by TG-43 protocol times the ICF. To validate the ICF methodology, dose absorbed in spherical phantoms with large tissue heterogeneities was compared using the TG-43 formalism corrected for heterogeneity versus Monte Carlo simulations. The agreement between Monte Carlo simulations and the ICF method remained within 5% in soft tissues up to several centimeters from a Pd-103 source. Compared to Monte Carlo, the ICF methods can easily be integrated into a clinical treatment planning system and it does not require the detailed internal structure of the source or the photon phase-space.
Energy performance of an architectural fabric roof: Experimental and analytical results
Gridley, R.B.; Hart, G.H.; Goss, W.P.
1985-01-01
As part of a research program on the thermal performance of translucent fabric-covered buildings, a comparison between measured and predicted fabric roof heat transfer was made. Predictions, based on a steady-state ASHRAE calculation technique, were compared against measured heat transfer through three different roof systems operating under outside weather conditions. The goals of the study were to evaluate the ability to predict the net energy transfer through the fabric roof systems tested, to identify parameters that would contribute to major differences between the measured and predicted results, and to recommend improvements to those parameters. It is expected that those improvements could be made in the computer program, DOE-2. The heat transfer through a single-layer, a double-layer, and a translucent insulated fabric roof system was measured in a vertical heat flow, guarded hot box located outdoors in Granville, Ohio. The results obtained by comparing the measured and predicted net heat transfer through the three roof systems indicated that the ASHRAE calculational technique predicted heat loss to within +. 25%, but it consistently overpredicted the heat gain during cooling load situations.
NASA Astrophysics Data System (ADS)
Mashouf, Shahram; Lechtman, Eli; Beaulieu, Luc; Verhaegen, Frank; Keller, Brian M.; Ravi, Ananth; Pignol, Jean-Philippe
2013-09-01
The American Association of Physicists in Medicine Task Group No. 43 (AAPM TG-43) formalism is the standard for seeds brachytherapy dose calculation. But for breast seed implants, Monte Carlo simulations reveal large errors due to tissue heterogeneity. Since TG-43 includes several factors to account for source geometry, anisotropy and strength, we propose an additional correction factor, called the inhomogeneity correction factor (ICF), accounting for tissue heterogeneity for Pd-103 brachytherapy. This correction factor is calculated as a function of the media linear attenuation coefficient and mass energy absorption coefficient, and it is independent of the source internal structure. Ultimately the dose in heterogeneous media can be calculated as a product of dose in water as calculated by TG-43 protocol times the ICF. To validate the ICF methodology, dose absorbed in spherical phantoms with large tissue heterogeneities was compared using the TG-43 formalism corrected for heterogeneity versus Monte Carlo simulations. The agreement between Monte Carlo simulations and the ICF method remained within 5% in soft tissues up to several centimeters from a Pd-103 source. Compared to Monte Carlo, the ICF methods can easily be integrated into a clinical treatment planning system and it does not require the detailed internal structure of the source or the photon phase-space.
Nuclear level densities below 40 MeV excitation energy in the mass region A ≃ 50
NASA Astrophysics Data System (ADS)
Avrigeanu, M.; Ivaşcu, M.; Avrigeanu, V.
1990-09-01
Consistent pre-equilibrium emission and statistical model calculations of fast neutron induced reaction cross sections are used to validate nuclear level densities for excitation energies up to 40 MeV in the mass region A ≃50. A “composed” level density approach has been employed by using the back-shifted Fermi gas model for excitation energies lower than 12 MeV and a realistic analytical formula for higher excitations. In the transition region from the BSFG model range to that of full applicability of the realistic formula, an interpolation between the predictions of the two models is adopted. The interpolation rule, suggested by microscopic level density calculations, has been validated through the comparison of the calculated and experimental cross sections.
Quantifying the Level of Cross-State Renewable Energy Transactions
Jenny Heeter, Philipp Beiter, Francisco Flores-Espino, David Hurlbut, Chang Liu
2015-02-01
This analysis provides first-ever assessment of the extent to which renewable energy is crossing state borders to be used to meet renewable portfolio standard (RPS) requirements. Two primary methods for data collection are Renewable Energy Certificate (REC) tracking and power flow estimates. Data from regional REC tracking systems, state agencies, and utility compliance reports help understand how cross-state transactions have been used to meet RPS compliance. Data on regional renewable energy flow use generator-specific information primarily sourced from EIA, SNL Energy, and FERC Form 1 filings. The renewable energy examined through this method may or may not have actually been used to meet RPS compliance.
New Perspective on Formation Energies and Energy Levels of Point Defects in Nonmetals
NASA Astrophysics Data System (ADS)
Ramprasad, R.; Zhu, H.; Rinke, Patrick; Scheffler, Matthias
2012-02-01
We propose a powerful scheme to accurately determine the formation energy and thermodynamic charge transition levels of point defects in nonmetals. Previously unknown correlations between defect properties and the valence-band width of the defect-free host material are identified allowing for a determination of the former via an accurate knowledge of the latter. These correlations are identified through a series of hybrid density-functional theory computations and an unbiased exploration of the parameter space that defines the Hyde-Scuseria-Ernzerhof family of hybrid functionals. The applicability of this paradigm is demonstrated for point defects in Si, Ge, ZnO, and ZrO2.
Barrie, A; Coward, W A
1985-09-01
The doubly labelled water method involves the administration of water enriched in 2H and 18O followed by determination of the turnover rates of these isotopes. Since 18O is eliminated from the body as both CO2 and water, while 2H leaves only as water, the difference between the two turnover rates provides a measure of CO2 production and hence energy expenditure. Isotopic analysis by conventional stable isotope ratio analysis (SIRA) is labour intensive and time consuming, as it requires off-line conversion of water samples to gases (H2 and CO2) followed by sequential analysis for each of the two isotopes using the mass spectrometer. Lack of suitable automated instrumentation with the ability to process large numbers of samples has prevented routine application of the method. We describe here an automated technique in which body water samples (urine, saliva, breath water or milk) are analysed simultaneously for 2H and 18O. The single bench system comprises two mass spectrometer analysers, one for measuring 2H from H2 gas, the other for measuring 18O from the water vapour (masses 18, 20). Both analysers share a common heated inlet system into which microlitre quantities of the body fluids are injected from an autosampler (102 samples). The water vapour flows both directly to one analyser for 18O measurement and into a uranium reduction furnace for conversion to H2, prior to 2H measurement by the second analyser. Both analysers also share vacuum and electronic components, enabling savings in both space and cost. In this paper we present results illustrating performance characteristics and procedures for routine application to human subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
DEVELOPMENT OF TECHNOLOGIES AND ANALYTICAL CAPABILITIES FOR VISION 21 ENERGY PLANTS
Maxwell Osawe; Madhave Symlal; Krishna Thotapalli; and Stephen Zitney
2003-04-30
This is the tenth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40954. The goal of the project is to develop and demonstrate a software framework to enable virtual simulation of Vision 21 plants. During the last quarter much progress was made in software development. The CO wrapper template was developed for the integration of Alstom Power proprietary code INDVU. The session management tasks were completed. The multithreading capability was made functional so that user of the integrated simulation may directly interact with the CFD software. The V21-Controller and the Fluent CO wrapper were upgraded to CO v.1.0. The testing and debugging of the upgraded software is ongoing. Testing of the integrated software was continued. A list of suggested GUI enhancements was made. Remote simulation capability was successfully tested using two networked Windows machines. Work on preparing the release version progressed: CFD database was enhanced, a convergence detection capability was implemented, a Configuration Wizard for low-order models was developed, and the Configuration Wizard for Fluent was enhanced. During the last quarter good progress was made in software demonstration. Various simplified versions of Demo Case 1 were used to debug Configuration Wizard and V21-Controller. The heat exchanger model in FLUENT was calibrated and the energy balance was verified. The INDVU code was integrated into the V21-Controller, and the integrated model is being debugged. A sensitivity loop was inserted into Demo Case 2 to check whether the simulation converges over the desired load range. Work on converting HRSGSIM code to run in batch mode was started. Work on calibrating Demo Case 2 was started.
Busche, S.
2010-12-01
This report takes a broad look at the status of local clean energy policies in the United States to develop a better understanding of local clean energy policy development and the interaction between state and local policies. To date, the majority of clean energy policy research focuses on the state and federal levels. While there has been a substantial amount of research on local level climate change initiatives, this is one of the first analyses of clean energy policies separate from climate change initiatives. This report is one in a suite of reports analyzing clean energy and climate policy development at the local, state, and regional levels.
Busche, S.
2010-12-01
This report takes a broad look at the status of local clean energy policies in the United States to develop a better understanding of local clean energy policy development and the interaction between state and local policies. To date, the majority of clean energy policy research focuses on the state and federal levels. While there has been a substantial amount of research on local level climate change initiatives, this is one of the first analyses of clean energy policies separate from climate change initiatives. This report is one in a suite of reports analyzing clean energy and climate policy development at the local, state, and regional levels.
Aznar, Alexandra; Day, Megan; Doris, Elizabeth; Mathur, Shivani; Donohoo-Vallett, Paul
2015-07-08
The Cities-LEAP technical report, City-Level Energy Decision Making: Data Use in Energy Planning, Implementation, and Evaluation in U.S. Cities, explores how a sample of cities incorporates data into making energy-related decisions. This report provides the foundation for forthcoming components of the Cities-LEAP project that will help cities improve energy decision making by mapping specific city energy or climate policies and actions to measurable impacts and results.
Analytical structure and properties of Coulomb wave functions for real and complex energies
NASA Astrophysics Data System (ADS)
Humblet, J.
1984-07-01
The radical Coulomb wave functions are analysed in their dependence on the energy E considered as a complex parameter. Repulsive and attractive fields are both considered. First turning to the function Φl ∝ r- l-1 Fl introduced by Briet, slightly modifying its definition, and assuming that the angular momentum is also a complex parameter, for which the notation L is used, it is proved that ΦL is an entire function of both E and L. From an expansion of the regular Whittaker function given by Buchholz, the Taylor expansion of ΦL in powers of E and a simple recurrence relation for its coefficients are easily obtained. The expansion of the regular function Fl is readily obtained from that of ΦL for L = l, but the irregular function Gl contains Φl and ∂Φ L/∂L for L = l and - l-1. Having proved that the expansion obtained for ΦL in powers of E can also be regarded as a uniformly convergent series of entire functions of L, the derivative ∂Φ L/∂L can be obtained by term-by-term derivation. This method for obtaining the expansion of Gl is straightforward and leads to a final result involving essentially: (i) the conventional function h(η) = 1/2ψ(1 + iη) + 1/2ψ(1 - iη) - ln η which is singular at η = ∞, i.e., at k = 0; (ii) two entire functions of E, namely Φl and Ψl; the terms of the expansion of the latter in powers of E contain only Bessel functions multiplied by Bernoulli numbers and coefficients easily obtained from a simple recurrence relation. As an application of the above results, the last sections contain: (i) an alternate from of Gl expansion useful in numerical computations; (ii) the definition and expansion of two linearly independent solutions of the Coulomb equation which are entire in E; (iii) the expansion and threshold properties of the outgoing and incoming solutions, Ol and Il, corresponding to those we have obtained for Fl and Gl.
DEVELOPMENT OF TECHNOLOGIES AND ANALYTICAL CAPABILITIES FOR VISION 21 ENERGY PLANTS
Madhava Syamlal; Maxwell Osawe; Stephen Zitney; Lewis Collins; David Sloan; Woodrow Fiveland; Frank Joop; Philip Simon; K. Joseph Cleetus
2005-04-01
To accelerate the development of advanced power plants, DOE's Vision 21 program identified the need for an integrated suite of software tools that could be used to simulate and visualize new plant concepts. Existing process simulation software did not meet this objective of virtual-plant simulation. Sophisticated models of many individual equipment items are available; however, a seamless coupling capability that would integrate the advanced equipment (component) models to the process (system) simulation software remained to be developed. The inability to use models in an integrated manner causes knowledge loss (e.g., knowledge captured in detailed equipment models is usually not available in process simulation) and modeling inconsistencies (e.g., physical properties and reaction kinetics data in different models are not the same). A team consisting of Fluent Inc., ALSTOM Power Inc., Aspen Technology Inc., Intergraph Corporation, and West Virginia University, in collaboration with the National Energy Technology Laboratory (NETL), addressed this challenge in a project performed over the period from October 2000 through December 2004. In this project the integration of the cycle analysis software was based on widely used commercial software: Aspen Plus{reg_sign} for process simulation and FLUENT{reg_sign} for computational fluid dynamics (CFD) modeling of equipment items. The integration software was designed to also include custom (in-house, proprietary, legacy) equipment models that often encapsulate the experience from the many years of designing and operating the equipment. The team adopted CAPE-OPEN (CO) interfaces, the de facto international standard for communication among process models, for exchanging information between software. The software developed in this project is the first demonstration of the use of CO interfaces to link CFD and custom equipment models with process simulators. New interface requirements identified during this project were
Energy levels and transition probability matrix elements of ruby for maser applications
NASA Technical Reports Server (NTRS)
Berwin, R. W.
1971-01-01
Program computes fine structure energy levels of ruby as a function of magnetic field. Included in program is matrix formulation, each row of which contains a magnetic field and four corresponding energy levels.
Nakata, Hiroya; Fedorov, Dmitri G; Zahariev, Federico; Schmidt, Michael W; Kitaura, Kazuo; Gordon, Mark S; Nakamura, Shinichiro
2015-03-28
Analytic second derivatives of the energy with respect to nuclear coordinates have been developed for spin restricted density functional theory (DFT) based on the fragment molecular orbital method (FMO). The derivations were carried out for the three-body expansion (FMO3), and the two-body expressions can be obtained by neglecting the three-body corrections. Also, the restricted Hartree-Fock (RHF) Hessian for FMO3 can be obtained by neglecting the density-functional related terms. In both the FMO-RHF and FMO-DFT Hessians, certain terms with small magnitudes are neglected for computational efficiency. The accuracy of the FMO-DFT Hessian in terms of the Gibbs free energy is evaluated for a set of polypeptides and water clusters and found to be within 1 kcal/mol of the corresponding full (non-fragmented) ab initio calculation. The FMO-DFT method is also applied to transition states in SN2 reactions and for the computation of the IR and Raman spectra of a small Trp-cage protein (PDB: 1L2Y). Some computational timing analysis is also presented.
Nakata, Hiroya; Fedorov, Dmitri G.; Zahariev, Federico; Schmidt, Michael W.; Gordon, Mark S.; Kitaura, Kazuo; Nakamura, Shinichiro
2015-03-28
Analytic second derivatives of the energy with respect to nuclear coordinates have been developed for spin restricted density functional theory (DFT) based on the fragment molecular orbital method (FMO). The derivations were carried out for the three-body expansion (FMO3), and the two-body expressions can be obtained by neglecting the three-body corrections. Also, the restricted Hartree-Fock (RHF) Hessian for FMO3 can be obtained by neglecting the density-functional related terms. In both the FMO-RHF and FMO-DFT Hessians, certain terms with small magnitudes are neglected for computational efficiency. The accuracy of the FMO-DFT Hessian in terms of the Gibbs free energy is evaluated for a set of polypeptides and water clusters and found to be within 1 kcal/mol of the corresponding full (non-fragmented) ab initio calculation. The FMO-DFT method is also applied to transition states in S{sub N}2 reactions and for the computation of the IR and Raman spectra of a small Trp-cage protein (PDB: 1L2Y). Some computational timing analysis is also presented.
NASA Astrophysics Data System (ADS)
Nakata, Hiroya; Fedorov, Dmitri G.; Zahariev, Federico; Schmidt, Michael W.; Kitaura, Kazuo; Gordon, Mark S.; Nakamura, Shinichiro
2015-03-01
Analytic second derivatives of the energy with respect to nuclear coordinates have been developed for spin restricted density functional theory (DFT) based on the fragment molecular orbital method (FMO). The derivations were carried out for the three-body expansion (FMO3), and the two-body expressions can be obtained by neglecting the three-body corrections. Also, the restricted Hartree-Fock (RHF) Hessian for FMO3 can be obtained by neglecting the density-functional related terms. In both the FMO-RHF and FMO-DFT Hessians, certain terms with small magnitudes are neglected for computational efficiency. The accuracy of the FMO-DFT Hessian in terms of the Gibbs free energy is evaluated for a set of polypeptides and water clusters and found to be within 1 kcal/mol of the corresponding full (non-fragmented) ab initio calculation. The FMO-DFT method is also applied to transition states in SN2 reactions and for the computation of the IR and Raman spectra of a small Trp-cage protein (PDB: 1L2Y). Some computational timing analysis is also presented.
Calculation of astrophysical S factor at low energy levels
NASA Astrophysics Data System (ADS)
Andic, Halil Ibrahim; Ozer, Okan
2017-02-01
Nuclear reactions are very important for the structure, evolution, nucleosynthesis and various observational manifestations of main-sequence stars, white dwarfs and neutron stars. For astrophysical applications, one needs to know value of S-factor for many reactions at low energies. The experimental measurements of cross-sections at such low energies are essentially not easily available since the Coulomb barrier. Theoretical calculations are model dependent, so that nuclear physics uncertainties of calculated S-factor can be substantial. Using the supersymmetric quantum mechanics one can obtain the supersymmetric partner potential that can vary by several orders of magnitude in the energy range of a given reaction in the calculation of S factor. Since the determination of reaction rates requires accurate values of cross sections at very low energies, then in order to eliminate the main part of the energy dependence of these cross sections one makes use of the astrophysical S-factor in Taylor Expansion series about zero-energy.
NASA Astrophysics Data System (ADS)
Eldardiry, H. A.; Unruh, H. G., Sr.; Habib, E. H.; Tidwell, V. C.
2016-12-01
Recent community initiatives have identified key foundational knowledge gaps that need to be addressed before transformative solutions can be made in the area of Food, Energy and Water (FEW) nexus. In addition, knowledge gaps also exist in the area of FEW education and needs to be addressed before we can make an impact on building the next generation FEW workforces. This study reports on the development of a pilot learning-module that focuses on two elements of the FEW nexus, Energy and Water. The module follows an active-learning approach to develop a set of student-centered learning activities using FEW datasets situated in real-world settings in the contiguous US. The module is based on data-driven learning exercises that incorporate different geospatial layers and manipulate datasets at a watershed scale representing the eight-digit Hydrologic Unit Code (HUC8). Examples of such datasets include water usage by different demand sectors (available from the US Geological Survey, USGS), and power plants stratified by energy source, cooling technology, and plant capacity (available from the US Energy Information Administration, EIA). The module is structured in three sections: (1) introduction to the water and energy systems, (2) quantifying stresses on water system at a catchment scale, and (3) scenario-based analysis on the interdependencies in the water-energy systems. Following a data-analytic framework, the module guides students to make different assumptions about water use growth rates and see how these new water demands will impinge on freshwater supplies. The module engages students in analysis that examines how thermoelectric water use would depend on assumptions about future demand for electricity, power plant fuel source, cooling type, and carbon sequestration. Students vary the input parameters, observe and assess the effect on water use, and address gaps via non-potable water resources (e.g., municipal wastewater). The module is implemented using a web
Kaup, Moritz; Scholtz, Jan-Erik; Engler, Alexander; Albrecht, Moritz H; Bauer, Ralf W; Kerl, J Matthias; Beeres, Martin; Lehnert, Thomas; Vogl, Thomas J; Wichmann, Julian L
2016-01-01
The aim of the study was to evaluate objective and subjective image qualities of virtual monoenergetic imaging (VMI) in dual-source dual-energy computed tomography (DECT) and optimal kiloelectron-volt (keV) levels for lung cancer. Fifty-nine lung cancer patients underwent chest DECT. Images were reconstructed as VMI series at energy levels of 40, 60, 80, and 100 keV and standard linear blending (M_0.3) for comparison. Objective and subjective image qualities were assessed. Lesion contrast peaked in 40-keV VMI reconstructions (2.5 ± 2.9) and 60 keV (1.9 ± 3.0), which was superior to M_0.3 (0.5 ± 2.7) for both comparisons (P < 0.001). Compared with M_0.3, subjective ratings were highest for 60-keV VMI series regarding general image quality (4.48 vs 4.52; P = 0.74) and increased for lesion demarcation (4.07 vs 4.84; P < 0.001), superior to all other VMI series (P < 0.001). Image sharpness was similar between both series. Image noise was rated superior in the 80-keV and M_0.3 series, followed by 60 keV. Virtual monoenergetic imaging reconstructions at 60-keV provided the best combination of subjective and objective image qualities in DECT of lung cancer.
DEVELOPMENT OF TECHNOLOGIES AND ANALYTICAL CAPABILITIES FOR VISION 21 ENERGY PLANTS
Madhava Syamlal, Ph.D.
2001-07-10
The training of a new project team member was completed (Task 2.1). The Software Requirements Document was written (Task 2.3). It was determined that the CAPE-OPEN interfaces are sufficient for the communication between Fluent and V21 Controller (Task 2.4). The AspenPlus-Fluent prototype on allyl/triacetone alcohol production was further developed to assist the GUI and software design tasks. The prototype was also used to analyze the sensitivity of a process simulation result with respect to a parameter in a CFD model embedded in the process simulation. Thus the integration of process simulation and CFD provides additional process insights and enables the engineer to optimize overall process performance (e.g., product purity and yield) with respect to important CFD design and operation parameters (e.g., CSTR shaft speed). A top-level design of the V21 Controller was developed and discussed. A draft version of the Software Design Document was written (Task 2.5/2.6). A preliminary software development plan was outlined. At first the V21 Controller will be developed and tested in two parts--a part that communicates with Fluent and a part that communicates with Aspen Plus. Then the two parts will be combined and tested with the allyl/triacetone alcohol flow sheet simulation. Much progress was made in writing the code for the two parts (Task 2.7). A requirement for pre-configured models was identified and added to the software requirements document (Task 2.9). Alstom Power's INDVU code was ported to the PC platform and calibrated. Aspen Plus model of the RP&L unit was improved to reflect the latest information received on the unit. Thus the preparation for linking INDVU code with the Aspen Plus model of RP&L unit is complete (Task 2.14). A report describing Demo Case 1 was written and submitted to DOE for review and approval (Task 3.1). The first Advisory Board meeting was held at the Fluent Users Group Meeting on June 6th. At the Advisory Board meeting, the project was
Hadron intensity and energy spectrum at 4380 m above level
NASA Technical Reports Server (NTRS)
Cananov, S. D.; Chadranyan, E. K.; Khizanishvili, L. A.; Ladaria, N. K.; Roinishvili, N. N.
1985-01-01
The flux value of hadrons with E (sup gamma) h or = 5 TeV, where E (sup gamma) h or = is the energy transferred into electromagnetic component is presented. It is shown that the energy spectrum slope beta of hadrons with E h or = 20 TeV is equal to 1.9.
Highlands County Energy Education Activities--High School Level.
ERIC Educational Resources Information Center
Allen, Rodney F., Ed.
Presented are five instructional units, developed by the Tri-County Teacher Education Center, for the purpose of educating secondary school students on Florida's unique energy problems. Unit one provides a series of value clarification and awareness activities as an introduction to energy. Unit two uses mathematics exercises to examine energy…
Highlands County Energy Education Activities--High School Level.
ERIC Educational Resources Information Center
Allen, Rodney F., Ed.
Presented are five instructional units, developed by the Tri-County Teacher Education Center, for the purpose of educating secondary school students on Florida's unique energy problems. Unit one provides a series of value clarification and awareness activities as an introduction to energy. Unit two uses mathematics exercises to examine energy…
ERIC Educational Resources Information Center
MacNeill, Sheila; Campbell, Lorna M.; Hawksey, Martin
2014-01-01
This article presents an overview of the development and use of analytics in the context of education. Using Buckingham Shum's three levels of analytics, the authors present a critical analysis of current developments in the domain of learning analytics, and contrast the potential value of analytics research and development with real world…
NASA Astrophysics Data System (ADS)
Yun, Dong-Jin; Shin, Weon-Ho; Bulliard, Xavier; Park, Jong Hwan; Kim, Seyun; Chung, Jae Gwan; Kim, Yongsu; Heo, Sung; Kim, Seong Heon
2016-08-01
A novel, direct method for the characterization of the energy level alignments at bulk-heterojunction (BHJ)/electrode interfaces on the basis of electronic spectroscopy measurements is proposed. The home-made in situ photoemission system is used to perform x-ray/ultraviolet photoemission spectroscopy (XPS/UPS), reflection electron energy loss spectroscopy (REELS) and inverse photoemission spectroscopy of organic-semiconductors (OSCs) deposited onto a Au substrate. Through this analysis system, we are able to obtain the electronic structures of a boron subphthalocyanine chloride:fullerene (SubPC:C60) BHJ and those of the separate OSC/electrode structures (SubPC/Au and C60/Au). Morphology and chemical composition analyses confirm that the original SubPC and C60 electronic structures remain unchanged in the electrodes prepared. Using this technique, we ascertain that the position and area of the nearest peak to the Fermi energy (EF = 0 eV) in the UPS (REELS) spectra of SubPC:C60 BHJ provide information on the highest occupied molecular orbital level (optical band gap) and combination ratio of the materials, respectively. Thus, extracting the adjusted spectrum from the corresponding SubPC:C60 BHJ UPS (REELS) spectrum reveals its electronic structure, equivalent to that of the C60 materials. This novel analytical approach allows complete energy-level determination for each combination ratio by separating its electronic structure information from the BHJ spectrum.
Department of Energy pretreatment of high-level and low-level wastes
McGinnis, C.P.; Hunt, R.D.
1995-12-31
The remediation of the 1 {times} 10{sup 8} gal of highly radioactive waste in the underground storage tanks (USTs) at five US Department of Energy (DOE) sites is one of DOE`s greatest challenges. Therefore, the DOE Office of Environmental Management has created the Tank Focus Area (TFA) to manage an integrated technology development program that results in the safe and efficient remediation of UST waste. The TFA has divided its efforts into five areas, which are safety, characterization, retrieval/closure, pretreatment, and immobilization. All DOE pretreatment activities are integrated by the Pretreatment Technical Integration Manager of the TFA. For FY 1996, the 14 pretreatment tasks are divided into 3 systems: supernate separations, sludge treatment, and solid/liquid separation. The plans and recent results of these TFA tasks, which include two 25,000-gal demonstrations and two former TFA tasks on Cs removal, are presented. The pretreatment goals are to minimize the volume of high-level waste and the radioactivity in low-level waste.
Palmans, H; Al-Sulaiti, L; Andreo, P; Shipley, D; Lühr, A; Bassler, N; Martinkovič, J; Dobrovodský, J; Rossomme, S; Thomas, R A S; Kacperek, A
2013-05-21
The conversion of absorbed dose-to-graphite in a graphite phantom to absorbed dose-to-water in a water phantom is performed by water to graphite stopping power ratios. If, however, the charged particle fluence is not equal at equivalent depths in graphite and water, a fluence correction factor, kfl, is required as well. This is particularly relevant to the derivation of absorbed dose-to-water, the quantity of interest in radiotherapy, from a measurement of absorbed dose-to-graphite obtained with a graphite calorimeter. In this work, fluence correction factors for the conversion from dose-to-graphite in a graphite phantom to dose-to-water in a water phantom for 60 MeV mono-energetic protons were calculated using an analytical model and five different Monte Carlo codes (Geant4, FLUKA, MCNPX, SHIELD-HIT and McPTRAN.MEDIA). In general the fluence correction factors are found to be close to unity and the analytical and Monte Carlo codes give consistent values when considering the differences in secondary particle transport. When considering only protons the fluence correction factors are unity at the surface and increase with depth by 0.5% to 1.5% depending on the code. When the fluence of all charged particles is considered, the fluence correction factor is about 0.5% lower than unity at shallow depths predominantly due to the contributions from alpha particles and increases to values above unity near the Bragg peak. Fluence correction factors directly derived from the fluence distributions differential in energy at equivalent depths in water and graphite can be described by kfl = 0.9964 + 0.0024·zw-eq with a relative standard uncertainty of 0.2%. Fluence correction factors derived from a ratio of calculated doses at equivalent depths in water and graphite can be described by kfl = 0.9947 + 0.0024·zw-eq with a relative standard uncertainty of 0.3%. These results are of direct relevance to graphite calorimetry in low-energy protons but given that the fluence
Energy Spectroscopy of Andreev Levels between Two Superconductors
Morpurgo, A.F.; van Wees, B.J.; Klapwijk, T.M.; Borghs, G.
1997-11-01
We perform energy spectroscopy of Andreev reflection processes occurring at two superconducting electrodes connected in series via a ballistic two dimensional channel, by measuring the voltage dependence of that part of the conductance modulated by the macroscopic phase difference. The amplitude of the modulation oscillates as a function of energy and the phase exhibits an abrupt shift close to {pi} at the energy for which the amplitude is minimum. A microscopic theoretical description ascribes the phenomenon to the precursor of a bound state formed between the two superconductors. {copyright} {ital 1997} {ital The American Physical Society}
Semiclassical energy levels and the corresponding potentials in nonhydrogenic ions
NASA Astrophysics Data System (ADS)
Pankratov, P.; Meyer-Ter-Vehn, J.
1992-11-01
A semiclassical expression is derived for the potential seen by an nl-shell electron in a nonhydrogenic ion. Corresponding energies Enl are compared with experimental values and with results of self-consistent-field calculations.
Framework for State-Level Renewable Energy Market Potential Studies
This document provides a framework and next steps for state officials who require estimates of renewable energy market potential. The report gives insight into how to conduct a market potential study.
Calculation of the energy levels of lithium-like ions
NASA Astrophysics Data System (ADS)
Nadykto, B. A.
An attempt is made to develop a straightforward and sufficiently accurate method for calculating the energies of complex ion states. The method is based on Bohr's computational model and Sommerfeld's model in relativistic form (for circular orbits only). The method proposed here makes it possible to calculate excited ion states having different atomic and quantum numbers. A similar method can be used for calculating the energies of ion states with the number of electrons exceeding three.
New perspective on formation energies and energy levels of point defects in non-metals
NASA Astrophysics Data System (ADS)
Zhu, Hong; Rinke, Patrick; Scheffler, Matthias; Ramprasad, Rampi
2012-02-01
We propose a powerful scheme to accurately determine the formation energy and thermodynamic charge transition levels of point defects in non-metals. Previously unknown correlations between defect properties and the valence-band width of the defect-free host material are identified allowing for a determination of the former via an accurate knowledge of the latter. These correlations are identified through a series of hybrid density functional theory computations and an unbiased exploration of the parameter space that defines the Hyde-Scuseria-Ernzerhof family of hybrid-functionals. The applicability of this paradigm is demonstrated for point defects in several insulators, including Si, Ge, ZrO2 and ZnO
NASA Astrophysics Data System (ADS)
Ananthanarayan, B.; Caprini, Irinel; Das, Diganta; Imsong, I. Sentitemsu
2014-02-01
The two-pion contribution from low energies to the muon magnetic moment anomaly, although small, has a large relative uncertainty since in this region the experimental data on the cross sections are neither sufficient nor precise enough. It is therefore of interest to see whether the precision can be improved by means of additional theoretical information on the pion electromagnetic form factor, which controls the leading-order contribution. In the present paper, we address this problem by exploiting analyticity and unitarity of the form factor in a parametrization-free approach that uses the phase in the elastic region, known with high precision from the Fermi-Watson theorem and Roy equations for ππ elastic scattering as input. The formalism also includes experimental measurements on the modulus in the region 0.65-0.70 GeV, taken from the most recent e+e-→π+π- experiments, and recent measurements of the form factor on the spacelike axis. By combining the results obtained with inputs from CMD2, SND, BABAR, and KLOE, we make the predictions aμππ ,LO[2mπ,0.30 GeV]=(0.553±0.004)×10-10 and aμππ ,LO[0.30 GeV ,0.63 GeV]=(133.083±0.837)×10-10. These are consistent with the other recent determinations and have slightly smaller errors.
NASA Astrophysics Data System (ADS)
Kurylyk, Barret L.; McKenzie, Jeffrey M.; MacQuarrie, Kerry T. B.; Voss, Clifford I.
2014-08-01
Numerous cold regions water flow and energy transport models have emerged in recent years. Dissimilarities often exist in their mathematical formulations and/or numerical solution techniques, but few analytical solutions exist for benchmarking flow and energy transport models that include pore water phase change. This paper presents a detailed derivation of the Lunardini solution, an approximate analytical solution for predicting soil thawing subject to conduction, advection, and phase change. Fifteen thawing scenarios are examined by considering differences in porosity, surface temperature, Darcy velocity, and initial temperature. The accuracy of the Lunardini solution is shown to be proportional to the Stefan number. The analytical solution results obtained for soil thawing scenarios with water flow and advection are compared to those obtained from the finite element model SUTRA. Three problems, two involving the Lunardini solution and one involving the classic Neumann solution, are recommended as standard benchmarks for future model development and testing.
Kurylyk, Barret L.; McKenzie, Jeffrey M; MacQuarrie, Kerry T. B.; Voss, Clifford I.
2014-01-01
Numerous cold regions water flow and energy transport models have emerged in recent years. Dissimilarities often exist in their mathematical formulations and/or numerical solution techniques, but few analytical solutions exist for benchmarking flow and energy transport models that include pore water phase change. This paper presents a detailed derivation of the Lunardini solution, an approximate analytical solution for predicting soil thawing subject to conduction, advection, and phase change. Fifteen thawing scenarios are examined by considering differences in porosity, surface temperature, Darcy velocity, and initial temperature. The accuracy of the Lunardini solution is shown to be proportional to the Stefan number. The analytical solution results obtained for soil thawing scenarios with water flow and advection are compared to those obtained from the finite element model SUTRA. Three problems, two involving the Lunardini solution and one involving the classic Neumann solution, are recommended as standard benchmarks for future model development and testing.
NASA Astrophysics Data System (ADS)
Ho, Gregory S.; Lignères, Vincent L.; Carter, Emily A.
2008-07-01
We derive an analytic form of the Wang-Govind-Carter (WGC) [Wang , Phys. Rev. B 60, 16350 (1999)] kinetic energy density functional (KEDF) with the density-dependent response kernel. A real-space aperiodic implementation of the WGC KEDF is then described and used in linear scaling orbital-free density functional theory (OF-DFT) calculations.
NASA Astrophysics Data System (ADS)
Catanzarite, Joseph; Burke, Christopher J.; Li, Jie; Seader, Shawn; Haas, Michael R.; Batalha, Natalie; Henze, Christopher; Christiansen, Jessie; Kepler Project, NASA Advanced Supercomputing Division
2016-06-01
The Kepler Mission is developing an Analytic Completeness Model (ACM) to estimate detection completeness contours as a function of exoplanet radius and period for each target star. Accurate completeness contours are necessary for robust estimation of exoplanet occurrence rates.The main components of the ACM for a target star are: detection efficiency as a function of SNR, the window function (WF) and the one-sigma depth function (OSDF). (Ref. Burke et al. 2015). The WF captures the falloff in transit detection probability at long periods that is determined by the observation window (the duration over which the target star has been observed). The OSDF is the transit depth (in parts per million) that yields SNR of unity for the full transit train. It is a function of period, and accounts for the time-varying properties of the noise and for missing or deweighted data.We are performing flux-level transit injection (FLTI) experiments on selected Kepler target stars with the goal of refining and validating the ACM. “Flux-level” injection machinery inserts exoplanet transit signatures directly into the flux time series, as opposed to “pixel-level” injection, which inserts transit signatures into the individual pixels using the pixel response function. See Jie Li's poster: ID #2493668, "Flux-level transit injection experiments with the NASA Pleiades Supercomputer" for details, including performance statistics.Since FLTI is affordable for only a small subset of the Kepler targets, the ACM is designed to apply to most Kepler target stars. We validate this model using “deep” FLTI experiments, with ~500,000 injection realizations on each of a small number of targets and “shallow” FLTI experiments with ~2000 injection realizations on each of many targets. From the results of these experiments, we identify anomalous targets, model their behavior and refine the ACM accordingly.In this presentation, we discuss progress in validating and refining the ACM, and we
Energy Levels and the de Broglie Relationship for High School Students
ERIC Educational Resources Information Center
Gianino, Concetto
2008-01-01
In this article, four examples of possible lessons on energy levels for high school are described: a particle in a box, a finite square well, the hydrogen atom and a harmonic oscillator. The energy levels are deduced through the use of the steady-state condition and the de Broglie relationship. In particular, the harmonic oscillator energy levels…
Energy Levels and the de Broglie Relationship for High School Students
ERIC Educational Resources Information Center
Gianino, Concetto
2008-01-01
In this article, four examples of possible lessons on energy levels for high school are described: a particle in a box, a finite square well, the hydrogen atom and a harmonic oscillator. The energy levels are deduced through the use of the steady-state condition and the de Broglie relationship. In particular, the harmonic oscillator energy levels…
On the crossing of electronic energy levels of diatomic molecules at the large-D limit
NASA Astrophysics Data System (ADS)
Shi, Qicun; Kais, Sabre; Remacle, Françoise; Levine, R. D.
2001-06-01
Analytical and numerical results are presented for the intersection of electronic energies of the same space symmetry for electrons in the field of two Coulomb centers in D-dimensions. We discuss why such crossings are allowed and may be less "exceptional" than one could think because even for a diatomic molecule there is more than one parameter in the electronic Hamiltonian. For a one electron diatomic molecule at the large-D limit, the electronic energies are shown analytically to diverge quadratically from the point of their intersection. The one electron two Coulomb centers problem allows a separation of variables even when the charges on the two centers are not equal. The case of two electrons, where their Coulombic repulsion precludes an exact symmetry, is therefore treated in the large-D limit. It is then found that, in addition to the quadratic intersection, there is also a curve crossing where the energies diverge linearly.
A Quantum Model of Atoms (the Energy Levels of Atoms).
ERIC Educational Resources Information Center
Rafie, Francois
2001-01-01
Discusses the model for all atoms which was developed on the same basis as Bohr's model for the hydrogen atom. Calculates the radii and the energies of the orbits. Demonstrates how the model obeys the de Broglie's hypothesis that the moving electron exhibits both wave and particle properties. (Author/ASK)
Teaching Field Concept and Potential Energy at A-Level.
ERIC Educational Resources Information Center
Poon, C. H.
1986-01-01
Argues for a greater emphasis on the reality of fields in electronics and gravitation instruction. Advocates that the potential energy in a system be regarded as stored in the field rather than in the material bodies of the system. Provides a rationale and examples for this position. (ML)
Teaching Field Concept and Potential Energy at A-Level.
ERIC Educational Resources Information Center
Poon, C. H.
1986-01-01
Argues for a greater emphasis on the reality of fields in electronics and gravitation instruction. Advocates that the potential energy in a system be regarded as stored in the field rather than in the material bodies of the system. Provides a rationale and examples for this position. (ML)
A Quantum Model of Atoms (the Energy Levels of Atoms).
ERIC Educational Resources Information Center
Rafie, Francois
2001-01-01
Discusses the model for all atoms which was developed on the same basis as Bohr's model for the hydrogen atom. Calculates the radii and the energies of the orbits. Demonstrates how the model obeys the de Broglie's hypothesis that the moving electron exhibits both wave and particle properties. (Author/ASK)
Orbital Energy Levels in Molecular Hydrogen. A Simple Approach.
ERIC Educational Resources Information Center
Willis, Christopher J.
1988-01-01
Described are the energetics involved in the formation of molecular hydrogen using concepts that should be familiar to students beginning the study of molecular orbital theory. Emphasized are experimental data on ionization energies. Included are two-electron atomic and molecular systems. (CW)
Decreased energy levels can cause and sustain obesity.
Wlodek, Danuta; Gonzales, Michael
2003-11-07
Obesity has reached epidemic proportions and has become one of the major health problems in developed countries. Current theories consider obesity a result of overeating and sedentary life style and most efforts to treat or prevent weight gain concentrate on exercise and food intake. This approach does not improve the situation as may be seen from the steep increase in the prevalence of obesity. This encouraged us to reanalyse existing information and look for biochemical basis of obesity. Our approach was to ignore current theories and concentrate on experimental data which are described in scientific journals and are available from several databases. We developed and applied a Knowledge Discovery in Databases procedure to analyse metabolic data. We began with the contradictory information: in obesity, more calories are consumed than used up, suggesting that obese people should have excess energy. On the other side, obese people experience fatigue and decreased physical endurance that indicates diminished energy supply in the body. The result of our work is a chain of metabolic events leading to obesity. The crucial event is the inhibition of the TCA cycle at the step of aconitase. It disturbs energy metabolism and results in ATP deficiency with simultaneous fat accumulation. Further steps in obesity development are the consequences of diminished energy supply: inhibition of beta-oxidation, leptin resistance, increase in appetite and food intake and a decrease in physical activity. Thus, our theory shows that obesity does not have to be caused by overeating and sedentary life-style but may be the result of the "obese" change in metabolism which is forcing people to overeat and save energy to sustain metabolic functions of cells. This "obese" change is caused by environmental factors that activate chronic low-grade inflammatory process in the body linking obesity with the environment of developed countries.
Kim, J W; Mackenzie, J I; Clarkson, W A
2009-07-06
A simple analytical expression for threshold pump power in an end-pumped quasi-three-level solid-state laser, which takes into account the influence of energy-transfer-upconversion (ETU), is derived. This expression indicates that threshold pump power can be increased dramatically by ETU, especially in low gain lasers and lasers with pronounced three-level character due to the need for high excitation densities in the upper manifold to reach threshold. The analysis has been applied to an Er:YAG laser operating at 1645 nm in-band pumped by an Er,Yb fiber laser at 1532 nm. Predicted values for threshold pump power as a function of erbium doping concentration are in very good agreement with measured values. The results indicate that very low erbium doping levels (approximately 0.25 at.% or less) are required to avoid degradation in performance due to ETU even under continuous-wave lasing conditions in Er:YAG.
Energy balance regulation by endocannabinoids at central and peripheral levels.
Quarta, Carmelo; Mazza, Roberta; Obici, Silvana; Pasquali, Renato; Pagotto, Uberto
2011-09-01
Dysregulation of the endocannabinoid system (ECS) is a universal and, perhaps, causative feature of obesity. Central nervous system (CNS) circuits that regulate food intake were initially believed to be the targets for dysregulation. However, it is increasingly evident that endocannabinoids affect food intake, energy expenditure and substrate metabolism by acting on peripheral sites. Cannabinoid type 1 receptor (CB1r) antagonists can effectively treat obesity and associated metabolic alterations but, unfortunately, cause and exacerbate mood disorders. Drugs restricted to act on peripheral CB1rs might be safer and more effective, retaining the anti-obesity effects but lacking the adverse neurodepressive reactions. This review summarizes the emerging roles of the ECS in energy balance and discusses future pharmacological approaches for developing peripherally restricted CB1r antagonists.
Vandenabeele-Trambouze, O; Claeys-Bruno, M; Dobrijevic, M; Rodier, C; Borruat, G; Commeyras, A; Garrelly, L
2005-02-01
The need for criteria to compare different analytical methods for measuring extraterrestrial organic matter at ultra-trace levels in relatively small and unique samples (e.g., fragments of meteorites, micrometeorites, planetary samples) is discussed. We emphasize the need to standardize the description of future analyses, and take the first step toward a proposed international laboratory network for performance testing.
ERIC Educational Resources Information Center
Waern, Yvonne
It is suggested that a reader's idea structure will affect processing of incoming information. Two aspects of the idea structure are further developed--the truth value aspect and the analytic level aspect. The idea structure can be characterized by ideas consisting of propositions which are considered to be more or less true or false (beliefs), or…
Okayama, Satoshi; Seno, Ayako; Soeda, Tsunenari; Takami, Yasuhiro; Kawakami, Rika; Somekawa, Satoshi; Ishigami, Ken-Ichi; Takeda, Yukiji; Kawata, Hiroyuki; Horii, Manabu; Uemura, Shiro; Saito, Yoshihiko
2012-04-01
Dual-energy computed tomography (DE-CT) uses polyenergetic X-rays at 100- and 140-kVp tube energy, and generates 120-kVp composite images that are referred to as polyenergetic images (PEIs). Moreover, DE-CT can produce monoenergetic images (MEIs) at any effective energy level. We evaluated whether the image quality of coronary angiography is improved by optimizing the energy levels of DE-CT. We retrospectively evaluated data sets obtained from 24 consecutive patients using cardiac DE-CT at 100- and 140-kVp tube energy with a dual-source scanner. Signal-to-noise ratios (SNRs) were evaluated in the left ascending coronary artery in PEIs, and in MEIs reconstructed at 40, 50, 60, 70, 80, 90, 100, 130, 160 and 190 keV. Energy levels of 100, 120 and 140 kVp generated the highest SNRs in PEIs from 10, 12 and 2 patients, respectively, at 60, 70 and 80 keV in MEIs from 2, 10 and 10 patients, respectively, and at 90 and 100 keV in those from one patient each. Optimization of the energy level for each patient increased the SNR by 16.6% in PEIs (P < 0.0001) and by 18.2% in MEIs (P < 0.05), compared with 120-kVp composite images. The image quality of coronary angiography using DE-CT can be improved by optimizing the energy level for individual patients.
Horáček, Jiří; Paidarová, Ivana; Curík, Roman
2014-08-21
The method of analytical continuation in the coupling constant, which allows us to determine the energy and width of a shape resonance, has been applied to the study of the (2)B2g shape resonance of ethylene. The procedure was done in two steps. In the first step, we used commercially available quantum-chemistry programs to calculate the electronic energy of a neutral molecule and of a negative ion. In both calculations, the Hamiltonian was altered by the inclusion of an additional attractive potential that helps to keep the negative ion bound. In the second step, the energy difference between the neutral molecule and its negative ion was analytically continued by the use of the statistical Padé approximation.
Energy levels of isoelectronic impurities by large scale LDA calculations
Li, Jingbo; Wang, Lin-Wang
2002-11-22
Isoelectronic impurity states are localized states induced by stoichiometric single atom substitution in bulk semiconductor. Photoluminescence spectra indicate deep impurity levels of 0.5 to 0.9eV above the top of valence band for systems like: GaN:As, GaN:P, CdS:Te, ZnS:Te. Previous calculations based on small supercells seemingly confirmed these experimental results. However, the current ab initio calculations based on thousand atom supercells indicate that the impurity levels of the above systems are actually much shallower(0.04 to 0.23 eV), and these impurity levels should be compared with photoluminescence excitation spectra, not photoluminescence spectra.
Espinosa-Garcia, Joaquin; Rangel, Cipriano; Suleimanov, Yury V
2017-07-26
We have developed an analytical full-dimensional potential energy surface, named PES-2017, for the gas-phase hydrogen abstraction reaction between the cyano radical and methane. This surface is fitted using high-level ab initio information as input. Using the PES-2017 surface, a kinetics study was performed via two theoretical approaches: variational transition-state theory with multidimensional tunnelling (VTST-MT) and ring polymer molecular dynamics (RPMD). The results are compared with the experimental data. In the whole temperature range analysed, 300-1500 K, both theories agree within a factor of <2, reproducing the experimental behaviour taking into account the experimental uncertainties. At high temperatures, where the recrossing effects dominate and the RPMD theory is exact, both theories differ by a factor of about 20%; while at low temperatures this difference is larger, 45%. Note that in this temperature regime, the tunnelling effect is negligible. The CN + CH4/CD4 kinetic isotope effects are important, reproducing the scarce experimental evidence. The good agreement with the ab initio information used in the fitting process (self-consistency test) and with the kinetic behaviour in a wide temperature range gives confidence and strength to the new surface.
Okazaki, Mitsuyo; Yamashita, Shizuya
2016-01-01
Recently, we developed an analytical method for determining the lipid levels and particle numbers in lipoprotein subclasses covering a wide size range from chylomicrons to small high density lipoproteins, by using gel permeation high-performance liquid chromatography (GP-HPLC). The challenges in analytical methods on lipoprotein subclasses have been addressed from 1980 by Hara and Okazaki using commercial TSK gel permeation columns. Later, the improvements in the hardware, separation and detection of lipoproteins, and the data processing software, using a Gaussian distribution approximation to calculate lipid levels of lipoprotein subclasses, have been extensively utilized in these analytical methods for over thirty years. In this review, we describe on the recent advances in analytical methods on lipoprotein subclasses based on various techniques, and the calculation of particle numbers from lipid levels by GPHPLC using the "spherical particle model". Free/ester ratio of cholesterol in particular lipoprotein subclass was accurately estimated from triglyceride, total cholesterol (free and esterified) and the size of the particle based on this model originally proposed by Shen and Kezdy.
Binding energy levels of a slowly moving ion in dusty plasmas
NASA Astrophysics Data System (ADS)
Hu, Hongwei; Li, Fuli
2013-02-01
The near field electric potential of a slowly moving ion in complex plasmas is studied. We find that the potential consists of the Debye-Hückel potential, the wake potential, and the potential associated with charge fluctuations. The binding energy levels of the ion are calculated by use of the Ritz variation method. The results show that the binding energy levels are related to the magnetic quantum number m. The binding energy levels are affected by speed of the ion and dust grain number density. In contract to isolated ion or static ion in plasmas, the binding energy levels of the ion are pushed up and even become unbounded.
Xu, Tengfang; Flapper, Joris; Ke, Jing; Kramer, Klaas; Sathaye, Jayant
2012-02-01
The overall goal of the project is to develop a computer-based benchmarking and energy and water savings tool (BEST-Dairy) for use in the California dairy industry - including four dairy processes - cheese, fluid milk, butter, and milk powder. BEST-Dairy tool developed in this project provides three options for the user to benchmark each of the dairy product included in the tool, with each option differentiated based on specific detail level of process or plant, i.e., 1) plant level; 2) process-group level, and 3) process-step level. For each detail level, the tool accounts for differences in production and other variables affecting energy use in dairy processes. The dairy products include cheese, fluid milk, butter, milk powder, etc. The BEST-Dairy tool can be applied to a wide range of dairy facilities to provide energy and water savings estimates, which are based upon the comparisons with the best available reference cases that were established through reviewing information from international and national samples. We have performed and completed alpha- and beta-testing (field testing) of the BEST-Dairy tool, through which feedback from voluntary users in the U.S. dairy industry was gathered to validate and improve the tool's functionality. BEST-Dairy v1.2 was formally published in May 2011, and has been made available for free downloads from the internet (i.e., http://best-dairy.lbl.gov). A user's manual has been developed and published as the companion documentation for use with the BEST-Dairy tool. In addition, we also carried out technology transfer activities by engaging the dairy industry in the process of tool development and testing, including field testing, technical presentations, and technical assistance throughout the project. To date, users from more than ten countries in addition to those in the U.S. have downloaded the BEST-Dairy from the LBNL website. It is expected that the use of BEST-Dairy tool will advance understanding of energy and water
Element levels in birch and spruce wood ashes: green energy?
Reimann, Clemens; Ottesen, Rolf Tore; Andersson, Malin; Arnoldussen, Arnold; Koller, Friedrich; Englmaier, Peter
2008-04-15
Production of wood ash has increased strongly in the last ten years due to the increasing popularity of renewable and CO(2)-neutral heat and energy production via wood burning. Wood ashes are rich in many essential plant nutrients. In addition they are alkaline. The idea of using the waste ash as fertiliser in forests is appealing. However, wood is also known for its ability to strongly enrich certain heavy metals from the underlying soils, e.g. Cd, without any anthropogenic input. Concentrations of 26 chemical elements (Ag, As, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti, and Zn) in 40 samples each of birch and spruce wood ashes collected along a 120 km long transect in southern Norway are reported. The observed maximum concentrations are 1.3 wt.% Pb, 4.4 wt.% Zn and 203 mg/kg Cd in birch wood ashes. Wood ashes can thus contain very high heavy metal concentrations. Spreading wood ashes in a forest is a major anthropogenic interference with the natural biogeochemical cycles. As with the use of sewage sludge in agriculture the use of wood ashes in forests clearly needs regulation.
NASA Technical Reports Server (NTRS)
Yang, Charles; Sun, Wenjun; Tomblin, John S.; Smeltzer, Stanley S., III
2007-01-01
A semi-analytical method for determining the strain energy release rate due to a prescribed interface crack in an adhesively-bonded, single-lap composite joint subjected to axial tension is presented. The field equations in terms of displacements within the joint are formulated by using first-order shear deformable, laminated plate theory together with kinematic relations and force equilibrium conditions. The stress distributions for the adherends and adhesive are determined after the appropriate boundary and loading conditions are applied and the equations for the field displacements are solved. Based on the adhesive stress distributions, the forces at the crack tip are obtained and the strain energy release rate of the crack is determined by using the virtual crack closure technique (VCCT). Additionally, the test specimen geometry from both the ASTM D3165 and D1002 test standards are utilized during the derivation of the field equations in order to correlate analytical models with future test results. The system of second-order differential field equations is solved to provide the adherend and adhesive stress response using the symbolic computation tool, Maple 9. Finite element analyses using J-integral as well as VCCT were performed to verify the developed analytical model. The finite element analyses were conducted using the commercial finite element analysis software ABAQUS. The results determined using the analytical method correlated well with the results from the finite element analyses.
Huang, Bolong; Sun, Mingzi
2017-04-05
An energy conversion model has been established for the intrinsic persistent luminescence in solids related to the native point defect levels, formations, and transitions. In this study, we showed how the recombination of charge carriers between different defect levels along the zero phonon line (ZPL) can lead to energy conversions supporting the intrinsic persistent phosphorescence in solids. This suggests that the key driving force for this optical phenomenon is the pair of electrons hopping between different charged defects with negative-Ueff. Such a negative correlation energy will provide a sustainable energy source for electron-holes to further recombine in a new cycle with a specific quantum yield. This will help us to understand the intrinsic persistent luminescence with respect to native point defect levels as well as the correlations of electronics and energetics.
NASA Astrophysics Data System (ADS)
Goldstein, Blair S.
In the absence of strong U.S. federal renewable energy policies, state governments have taken the lead in passing legislation to promote wind energy. Studies have shown that many of these policies, including Renewable Portfolio Standards (RPS), have aided in the development of wind energy capacity nationwide. This paper seeks to analyze whether these state-level policies have led to an efficient development of U.S. wind energy. For the purposes of this paper, wind energy development is considered efficient if competitive markets enable wind capacity to be built in the most cost effective manner, allowing states to trade wind energy between high wind potential states and low wind potential states. This concept is operationalized by analyzing how state policies that incentivize the in-state development of wind energy impact where wind capacity is developed. A multivariate regression model examining wind capacity in the 48 contiguous United States that had some wind capacity between 1999 and 2008 found these in-state policies are associated with increased wind capacity, controlling for states' wind potential. The results suggest that state-level policies are distorting where wind is developed. These findings support the enactment of a more comprehensive federal energy policy, such as a national RPS, a cap-and-trade program, or a targeted federal transmission policy. These federal policies could spur national markets that would result in the more efficient development of U.S. wind energy.
NASA Astrophysics Data System (ADS)
Macleod, Christopher Kit; Braga, Joao; Arts, Koen; Ioris, Antonio; Han, Xiwu; Sripada, Yaji; van der Wal, Rene
2016-04-01
The number of local, national and international networks of online environmental sensors are rapidly increasing. Where environmental data are made available online for public consumption, there is a need to advance our understanding of the relationships between the supply of and the different demands for such information. Understanding how individuals and groups of users are using online information resources may provide valuable insights into their activities and decision making. As part of the 'dot.rural wikiRivers' project we investigated the potential of web analytics and an online survey to generate insights into the use of a national network of river level data from across Scotland. These sources of online information were collected alongside phone interviews with volunteers sampled from the online survey, and interviews with providers of online river level data; as part of a larger project that set out to help improve the communication of Scotland's online river data. Our web analytics analysis was based on over 100 online sensors which are maintained by the Scottish Environmental Protection Agency (SEPA). Through use of Google Analytics data accessed via the R Ganalytics package we assessed: if the quality of data provided by Google Analytics free service is good enough for research purposes; if we could demonstrate what sensors were being used, when and where; how the nature and pattern of sensor data may affect web traffic; and whether we can identify and profile these users based on information from traffic sources. Web analytics data consists of a series of quantitative metrics which capture and summarize various dimensions of the traffic to a certain web page or set of pages. Examples of commonly used metrics include the number of total visits to a site and the number of total page views. Our analyses of the traffic sources from 2009 to 2011 identified several different major user groups. To improve our understanding of how the use of this national
North Dakota Industrial Arts Teachers Handbook. Energy/Power Curriculum Guide, Level I.
ERIC Educational Resources Information Center
Mugan, Don
This handbook provides teachers with support material to more fully implement the North Dakota Energy and Power Curriculum Guide, Level I. It first presents the body of knowledge for Energy/Power Technology as taken from the curriculum guide. The guide is then addressed unit by unit, topic by topic. These seven units are covered: Energy/Power…
North Dakota Industrial Arts Teachers Handbook. Energy/Power Curriculum Guide, Level I.
ERIC Educational Resources Information Center
Mugan, Don
This handbook provides teachers with support material to more fully implement the North Dakota Energy and Power Curriculum Guide, Level I. It first presents the body of knowledge for Energy/Power Technology as taken from the curriculum guide. The guide is then addressed unit by unit, topic by topic. These seven units are covered: Energy/Power…
Quantifying the Level of Cross-State Renewable Energy Transactions (Presentation)
Heeter, J.; Beiter, P.; Flores, F.; Hurlbut, D.; Liu, C.
2015-02-01
This presentation and associated spreadsheet examine the level of cross-state renewable energy transactions. Most state renewable portfolio standard (RPS) policies allow for out-of-state renewable energy or renewable energy certificates to count towards compliance. This analysis focuses on compliance for 2012 and provides stakeholders with an understanding of the extent to which RPSs are being met.
24 CFR 990.185 - Utilities expense level: Incentives for energy conservation/rate reduction.
Code of Federal Regulations, 2012 CFR
2012-04-01
... for energy conservation/rate reduction. 990.185 Section 990.185 Housing and Urban Development... Calculating Formula Expenses § 990.185 Utilities expense level: Incentives for energy conservation/rate reduction. (a) General/consumption reduction. If a PHA undertakes energy conservation measures that...
24 CFR 990.185 - Utilities expense level: Incentives for energy conservation/rate reduction.
Code of Federal Regulations, 2014 CFR
2014-04-01
... for energy conservation/rate reduction. 990.185 Section 990.185 Housing and Urban Development... Calculating Formula Expenses § 990.185 Utilities expense level: Incentives for energy conservation/rate reduction. (a) General/consumption reduction. If a PHA undertakes energy conservation measures that...
24 CFR 990.185 - Utilities expense level: Incentives for energy conservation/rate reduction.
Code of Federal Regulations, 2013 CFR
2013-04-01
... for energy conservation/rate reduction. 990.185 Section 990.185 Housing and Urban Development... Calculating Formula Expenses § 990.185 Utilities expense level: Incentives for energy conservation/rate reduction. (a) General/consumption reduction. If a PHA undertakes energy conservation measures that...
Bote, David; Salvat, Francesc Jablonski, Aleksander
2009-11-15
Analytical formulas are presented for the easy calculation of cross sections for ionization of K, L and M shells of neutral atoms by impact of electrons and positrons with kinetic energies up to 1 GeV. Each formula contains a number of parameters that are characteristic of the element, the active electron shell and the projectile particle. The values of these parameters were determined by fitting the cross section values in an extensive database that was calculated recently by means of a composite algorithm that combines the distorted-wave and plane-wave Born approximations. Tables of parameter values are given for all elements, from hydrogen (Z=1) to einsteinium (Z=99). The proposed analytical expressions yield ionization cross sections that agree with those in the numerical database to within about 1%, except for projectiles with near-threshold energies.
Hratchian, Hrant P; Parandekar, Priya V; Raghavachari, Krishnan; Frisch, Michael J; Vreven, Thom
2008-01-21
An accurate first-principles treatment of chemical reactions for large systems remains a significant challenge facing electronic structure theory. Hybrid models, such as quantum mechanics:molecular mechanics (QM:MM) and quantum mechanics:quantum mechanics (QM:QM) schemes, provide a promising avenue for such studies. For many chemistries, including important reactions in materials science, molecular mechanics or semiempirical methods may not be appropriate, or parameters may not be available (e.g., surface chemistry of compound semiconductors such as indium phosphide or catalytic chemistry of transition metal oxides). In such cases, QM:QM schemes are of particular interest. In this work, a QM:QM electronic embedding model within the ONIOM (our own N-layer integrated molecular orbital molecular mechanics) extrapolation framework is presented. To define the embedding potential, we choose the real-system low-level Mulliken atomic charges. This results in a set of well-defined and unique embedding charges. However, the parametric dependence of the charges on molecular geometry complicates the energy gradient that is necessary for the efficient exploration of potential energy surfaces. We derive an efficient form for the forces where a single set of self-consistent field response equations is solved. Initial tests of the method and key algorithmic issues are discussed.
NASA Astrophysics Data System (ADS)
Goh, J. B.; Jamaludin, Z.; Jafar, F. A.; Mat Ali, M.; Mokhtar, M. N. Ali; Tan, C. H.
2017-06-01
Wasted kinetic energy recovery system (WKERS) is a wind renewable gadget installed above a cooling tower outlet to harvest the discharged wind for electrical regeneration purpose. The previous WKERS is operated by a horizontal axis wind turbine (HAWT) with delta blade design but the performance is still not at the optimum level. Perhaps, a better blade-shape design should be determined to obtain the optimal performance, as it is believed that the blade-shape design plays a critical role in HAWT. Hence, to determine a better blade-shape design for a new generation of WKERS, elliptical blade, swept blade and NREL Phase IV blade are selected for this benchmarking process. NREL Phase IV blade is a modern HAWT’s blade design by National Renewable Energy Laboratory (NREL) research lab. During the process of benchmarking, Computational Fluid Dynamics (CFD) analysis was ran by using SolidWorks design software, where all the designs are simulated with linear flow simulation. The wind speed in the simulation is set at 10.0 m/s, which is compatible with the average wind speed produced by a standard size cooling tower. The result is obtained by flow trajectories of air motion, surface plot and cut plot of the applied blade-shape. Besides, the aspect ratio of each blade is calculated and included as one of the reference in the comparison. Hence, the final selection of the best blade-shape design will bring to the new generation of WKERS.
NASA Astrophysics Data System (ADS)
Hratchian, Hrant P.; Parandekar, Priya V.; Raghavachari, Krishnan; Frisch, Michael J.; Vreven, Thom
2008-01-01
An accurate first-principles treatment of chemical reactions for large systems remains a significant challenge facing electronic structure theory. Hybrid models, such as quantum mechanics:molecular mechanics (QM:MM) and quantum mechanics:quantum mechanics (QM:QM) schemes, provide a promising avenue for such studies. For many chemistries, including important reactions in materials science, molecular mechanics or semiempirical methods may not be appropriate, or parameters may not be available (e.g., surface chemistry of compound semiconductors such as indium phosphide or catalytic chemistry of transition metal oxides). In such cases, QM:QM schemes are of particular interest. In this work, a QM:QM electronic embedding model within the ONIOM (our own N-layer integrated molecular orbital molecular mechanics) extrapolation framework is presented. To define the embedding potential, we choose the real-system low-level Mulliken atomic charges. This results in a set of well-defined and unique embedding charges. However, the parametric dependence of the charges on molecular geometry complicates the energy gradient that is necessary for the efficient exploration of potential energy surfaces. We derive an efficient form for the forces where a single set of self-consistent field response equations is solved. Initial tests of the method and key algorithmic issues are discussed.
Näykki, Teemu
2002-04-01
The use of silylation of glassware in mercury analytics was investigated. By treating the glassware with 5% (v/v) dichlorodimethylsilane in toluene, the surfaces of the vessels were inactivated. Method development proved that silylation can extend the range of stabile, contamination-free area as low as 1 ng/L mercury without any significant investments in laboratory clean-room facilities. The resilylation had to be done once a month.
Hinkelman, L M; Liu, D L; Metlay, L A; Waag, R C
1994-01-01
Ultrasonic pulse arrival time and energy level variations introduced by propagation through human abdominal wall specimens have been measured. A hemispheric transducer transmitted an ultrasonic pulse that was detected by a linear array transducer after propagation through an abdominal wall section. The array was translated in the elevation direction to collect data over a two-dimensional aperture. Differences in arrival time and energy level between the measured waveforms and calculated references that account for geometric delay and spreading were found. Plots of waveforms compensated for geometric path, maps of time delay differences and energy level fluctuations, and statistics derived from these for water paths and tissue paths characterize the measurement system and describe the time delay differences and energy level fluctuations caused by 14 different human abdominal wall specimens. Repeated measurements using the same specimens show that individual tissue path measurements are reproducible, the results depend on specimen position, and frozen storage of a specimen for three months does not appear to alter the time delay differences and energy level fluctuations produced by the specimen. Comparison of measurements at room and body temperature indicates that appreciably higher time delay differences occur at body temperature while energy level fluctuations and time delay difference patterns are less affected. For the 14 different abdominal wall specimens, the rms time delay differences and energy level fluctuations have average values of 43.0 ns and 3.30 dB, respectively, and the associated correlation lengths of the time delay differences and energy level fluctuations are 7.90 and 2.28 mm, respectively. The spatial patterns of time delay difference and energy level fluctuation in the reception plane appear largely uncorrelated, although some background variations in energy level fluctuation are similar to features in time delay difference maps. The results
Rotation vibration energy level clustering in the XB1 ground electronic state of PH2
NASA Astrophysics Data System (ADS)
Yurchenko, S. N.; Thiel, W.; Jensen, Per; Bunker, P. R.
2006-10-01
We use previously determined potential energy surfaces for the Renner-coupled XB1 and AA1 electronic states of the phosphino (PH 2) free radical in a calculation of the energies and wavefunctions of highly excited rotational and vibrational energy levels of the X˜ state. We show how spin-orbit coupling, the Renner effect, rotational excitation, and vibrational excitation affect the clustered energy level patterns that occur. We consider both 4-fold rotational energy level clustering caused by centrifugal distortion, and vibrational energy level pairing caused by local mode behaviour. We also calculate ab initio dipole moment surfaces for the X˜ and A˜ states, and the X˜-A˜ transition moment surface, in order to obtain spectral intensities.
Density and energy level of a deep-level Mg acceptor in 4H-SiC
NASA Astrophysics Data System (ADS)
Matsuura, Hideharu; Morine, Tatsuya; Nagamachi, Shinji
2015-01-01
Reliably determining the densities and energy levels of deep-level dominant acceptors in heavily doped wide-band-gap semiconductors has been a topic of recent discussion. In these discussions, the focus is on both Hall scattering factors for holes and distribution functions for acceptors. Mg acceptor levels in 4H-SiC seem to be deep, and so here the electrical properties of Mg-implanted 4H-SiC layers are studied by measuring Hall effects. The obtained Hall scattering factors are not reliable because they drop to less than 0.5 at high measurement temperatures. Moreover, the Fermi-Dirac distribution function is unsuitable for examining Mg acceptors because the obtained acceptor density is much higher than the concentration of implanted Mg atoms. However, by using a distribution function that includes the influence of the excited states of a deep-level acceptor, the density and energy level of Mg acceptors can be reliably determined.
AMPK: Regulating Energy Balance at the Cellular and Whole Body Levels
Hardie, D. Grahame; Ashford, Michael L. J.
2014-01-01
AMP-activated protein kinase appears to have evolved in single-celled eukaryotes as an adenine nucleotide sensor that maintains energy homeostasis at the cellular level. However, during evolution of more complex multicellular organisms, the system has adapted to interact with hormones so that it also plays a key role in balancing energy intake and expenditure at the whole body level. PMID:24583766
EPA’s Web Analytics Program collects, analyzes, and provides reports on traffic, quality assurance, and customer satisfaction metrics for EPA’s website. The program uses a variety of analytics tools, including Google Analytics and CrazyEgg.
Energy-level alignment at interfaces between manganese phthalocyanine and C60.
Waas, Daniel; Rückerl, Florian; Knupfer, Martin; Büchner, Bernd
2017-01-01
We have used photoelectron spectroscopy to determine the energy-level alignment at organic heterojunctions made of manganese phthalocyanine (MnPc) and the fullerene C60. We show that this energy-level alignment depends upon the preparation sequence, which is explained by different molecular orientations. Moreover, our results demonstrate that MnPc/C60 interfaces are hardly suited for application in organic photovoltaic devices, since the energy difference of the two lowest unoccupied molecular orbitals (LUMOs) is rather small.
NASA Technical Reports Server (NTRS)
Westphalen, H.; Spjeldvik, W. N.
1982-01-01
A theoretical method by which the energy dependence of the radial diffusion coefficient may be deduced from spectral observations of the particle population at the inner edge of the earth's radiation belts is presented. This region has previously been analyzed with numerical techniques; in this report an analytical treatment that illustrates characteristic limiting cases in the L shell range where the time scale of Coulomb losses is substantially shorter than that of radial diffusion (L approximately 1-2) is given. It is demonstrated both analytically and numerically that the particle spectra there are shaped by the energy dependence of the radial diffusion coefficient regardless of the spectral shapes of the particle populations diffusing inward from the outer radiation zone, so that from observed spectra the energy dependence of the diffusion coefficient can be determined. To insure realistic simulations, inner zone data obtained from experiments on the DIAL, AZUR, and ESRO 2 spacecraft have been used as boundary conditions. Excellent agreement between analytic and numerical results is reported.
1995-07-26
The Department of Energy`s (DOE) Assistant Secretary for Fossil Energy has overall programmatic responsibility for the Strategic Petroleum Reserve (SPR). The SPR Project Management Office (SPRPMO), located in New Orleans, Louisiana, and under the direction of the Project Manager, manages day-to-day project activities. The SPR currently has five underground crude oil storage facilities, and one marine terminal, on or near the Gulf Coasts of Texas and Louisiana. The purpose of this inspection was to review oversight of M and O and subcontractor laboratories performing analyses on samples taken for SPR environmental compliance and oil quality purposes. During this inspection, the M and O contractor operated on-site environmental laboratories at four of the SPR storage facilities, and oil quality laboratories at two of the facilities. The number of subcontractor laboratories varies depending on the need for analytical support. The objective of this inspection was to determine if the SPRPMO had implemented management systems to provide adequate oversight of M and O contractor analytical laboratory activities, as well as to ensure effective oversight of subcontractor analytical laboratories.
NASA Technical Reports Server (NTRS)
Westphalen, H.; Spjeldvik, W. N.
1982-01-01
A theoretical method by which the energy dependence of the radial diffusion coefficient may be deduced from spectral observations of the particle population at the inner edge of the earth's radiation belts is presented. This region has previously been analyzed with numerical techniques; in this report an analytical treatment that illustrates characteristic limiting cases in the L shell range where the time scale of Coulomb losses is substantially shorter than that of radial diffusion (L approximately 1-2) is given. It is demonstrated both analytically and numerically that the particle spectra there are shaped by the energy dependence of the radial diffusion coefficient regardless of the spectral shapes of the particle populations diffusing inward from the outer radiation zone, so that from observed spectra the energy dependence of the diffusion coefficient can be determined. To insure realistic simulations, inner zone data obtained from experiments on the DIAL, AZUR, and ESRO 2 spacecraft have been used as boundary conditions. Excellent agreement between analytic and numerical results is reported.
Effect of temperature-dependent energy-level shifts on a semiconductor's Peltier heat
NASA Astrophysics Data System (ADS)
Emin, David
1984-11-01
The Peltier heat of a charge carrier in a semiconductor is calculated for the situation in which the electronic energy levels are temperature dependent. The temperature dependences of the electronic energy levels, generally observed optically, arise from their dependences on the vibrational energy of the lattice (e.g., as caused by thermal expansion). It has been suggested that these temperature dependences will typically have a major effect on the Peltier heat. The Peltier heat associated with a given energy level is a thermodynamic quantity; it is the product of the temperature and the change of the entropy of the system when a carrier is added in that level. As such, the energy levels cannot be treated as explicitly temperature dependent. The electron-lattice interaction causing the temperature dependence must be expressly considered. It is found that the carrier's interaction with the atomic vibrations lowers its electronic energy. However, the interaction of the carrier with the atomic vibrations also causes an infinitesimal lowering (~1N) of each of the N vibrational frequencies. As a result, there is a finite carrier-induced increase in the average vibrational energy. Above the Debye temperature, this cancels the lowering of the carrier's electronic energy. Thus, the standard Peltier-heat formula, whose derivation generally ignores the temperature dependence of the electronic energy levels, is regained. This explains the apparent success of the standard formula in numerous analyses of electronic transport experiments.
NASA Technical Reports Server (NTRS)
Liechty, Derek S.; Lewis, Mark
2010-01-01
A new method of treating electronic energy level transitions as well as linking ionization to electronic energy levels is proposed following the particle-based chemistry model of Bird. Although the use of electronic energy levels and ionization reactions in DSMC are not new ideas, the current method of selecting what level to transition to, how to reproduce transition rates, and the linking of the electronic energy levels to ionization are, to the author s knowledge, novel concepts. The resulting equilibrium temperatures are shown to remain constant, and the electronic energy level distributions are shown to reproduce the Boltzmann distribution. The electronic energy level transition rates and ionization rates due to electron impacts are shown to reproduce theoretical and measured rates. The rates due to heavy particle impacts, while not as favorable as the electron impact rates, compare favorably to values from the literature. Thus, these new extensions to the particle-based chemistry model of Bird provide an accurate method for predicting electronic energy level transition and ionization rates in gases.
Bozkaya, Uğur
2014-10-14
An efficient implementation of analytic energy gradients and spin multiplicities for the density-fitted orbital-optimized second-order perturbation theory (DF-OMP2) [Bozkaya, U. J. Chem. Theory Comput. 2014, 10, 2371-2378] is presented. The DF-OMP2 method is applied to a set of alkanes, conjugated dienes, and noncovalent interaction complexes to compare the cost of single point analytic gradient computations with the orbital-optimized MP2 with the resolution of the identity approach (OO-RI-MP2) [Neese, F.; Schwabe, T.; Kossmann, S.; Schirmer, B.; Grimme, S. J. Chem. Theory Comput. 2009, 5, 3060-3073]. Our results demonstrate that the DF-OMP2 method provides substantially lower computational costs for analytic gradients than OO-RI-MP2. On average, the cost of DF-OMP2 analytic gradients is 9-11 times lower than that of OO-RI-MP2 for systems considered. We also consider aromatic bond dissociation energies, for which MP2 provides poor reaction energies. The DF-OMP2 method exhibits a substantially better performance than MP2, providing a mean absolute error of 2.5 kcal mol(-1), which is more than 9 times lower than that of MP2 (22.6 kcal mol(-1)). Overall, the DF-OMP2 method appears very helpful for electronically challenging chemical systems such as free radicals or other cases where standard MP2 proves unreliable. For such problematic systems, we recommend using DF-OMP2 instead of the canonical MP2 as a more robust method with the same computational scaling.
The effect of state-level funding on energy efficiency outcomes
NASA Astrophysics Data System (ADS)
Downs, Anna
Increasingly, states are formalizing energy efficiency policies. In 2010, states required utilities to budget $5.5 billion through ratepayer-funded energy efficiency programs, investing in both electricity and natural gas programs. However the size and spread of energy efficiency programs was strikingly different from state to state. This paper examines how far each dollar of state-level energy efficiency funding goes in producing efficiency gains. Many states have also pursued innovative policy actions to conserve electricity. Measures of policy effort are also included in this study, along with average electricity prices. The only variable that is consistently correlated with energy usage intensity across all models is electricity price. As politicians at local, state, and Federal levels continue to push for improved energy efficiency, the models in this paper provide a convincing impetus for focusing on strategies that raise energy prices.
Variational calculation of highly excited rovibrational energy levels of H2O2.
Polyansky, Oleg L; Kozin, Igor N; Ovsyannikov, Roman I; Małyszek, Paweł; Koput, Jacek; Tennyson, Jonathan; Yurchenko, Sergei N
2013-08-15
Results are presented for highly accurate ab initio variational calculation of the rotation-vibration energy levels of H2O2 in its electronic ground state. These results use a recently computed potential energy surface and the variational nuclear-motion programs WARV4, which uses an exact kinetic energy operator, and TROVE, which uses a numerical expansion for the kinetic energy. The TROVE calculations are performed for levels with high values of rotational excitation, J up to 35. The purely ab initio calculations of the rovibrational energy levels reproduce the observed levels with a standard deviation of about 1 cm(-1), similar to that of the J = 0 calculation, because the discrepancy between theory and experiment for rotational energies within a given vibrational state is substantially determined by the error in the vibrational band origin. Minor adjustments are made to the ab initio equilibrium geometry and to the height of the torsional barrier. Using these and correcting the band origins using the error in J = 0 states lowers the standard deviation of the observed-calculated energies to only 0.002 cm(-1) for levels up to J = 10 and 0.02 cm(-1) for all experimentally known energy levels, which extend up to J = 35.
Koput, Jacek
2015-06-30
The accurate ground-state potential energy function of imidogen, NH, has been determined from ab initio calculations using the multireference averaged coupled-pair functional (MR-ACPF) method in conjunction with the correlation-consistent core-valence basis sets up to octuple-zeta quality. The importance of several effects, including electron correlation beyond the MR-ACPF level of approximation, the scalar relativistic, adiabatic, and nonadiabatic corrections were discussed. Along with the large one-particle basis set, all of these effects were found to be crucial to attain "spectroscopic" accuracy of the theoretical predictions of vibration-rotation energy levels of NH.
Mathiassen, Astrid; Hollema, Siemon
2014-09-01
Energy deficiency is observed to be at odds with other food security indicators. In wealthier urban areas, the prevalence of energy deficiency is often higher than in poorer rural areas, whereas other food security indicators, such as food diversity, perform much better in urban than in rural areas. To investigate to what extent differences in physical activity levels influence dietary quantity and quality. Central to this analysis is the construction of a household activity index, a single measure that aims to capture the collective workload of the household. This paper uses data from Nepal and Uganda expenditure surveys that contain information on food consumption, as well as detailed information on how individual household members spend their time. Energy deficiency numbers are adjusted by the activity index, and the results are compared with the standard approach for calculating energy deficiency assuming light activity levels. Regressions are estimated to discuss demand for calories and diversity given the activity level. Accounting for differences in activity level has a large effect on energy deficiency figures, particularly in rural areas. The analysis shows that a higher household activity level significantly increases the calories consumed but lessens food diversity, suggesting that households with high activity levels sacrifice diversity for quantity in order to meet their energy requirements. Physical activity levels should be taken into account when interpreting empirical differences in food consumption levels for determining the prevalence of food insecurity and making allocation decisions for food security assistance.
Energy Efficiency Policy in the United States. Overview of Trends at Different Levels of Government
Doris, Elizabeth; Cochran, Jaquelin; Vorum, Martin
2009-12-01
This report catalogs by sector--buildings, transportation, industrial, and power--energy efficiency policies at the federal, state, and local levels, and identifies some prominent policy trends. Four key findings emerged from this report: 1) leadership on energy efficiency is necessary--and is found--at each level of government; 2) there is no widely accepted methodology for evaluating energy efficiency policies; 3) coordination among the three levels of government--and across sectors--is increasingly important, and there are opportunities to significantly improve policy performance through a unified strategy; and 4) there are efficiencies to be gained by informing policies in one sector with experience from others.
Energy Efficiency Policy in the United States: Overview of Trends at Different Levels of Government
Doris, E.; Cochran, J.; Vorum, M.
2009-12-01
This report catalogs by sector--buildings, transportation, industrial, and power--energy efficiency policies at the federal, state, and local levels, and identifies some prominent policy trends. Four key findings emerged from this report: 1) leadership on energy efficiency is necessary--and is found--at each level of government; 2) there is no widely accepted methodology for evaluating energy efficiency policies; 3) coordination among the three levels of government--and across sectors--is increasingly important, and there are opportunities to significantly improve policy performance through a unified strategy; and 4) there are efficiencies to be gained by informing policies in one sector with experience from others.
Energy Level Alignment at Aqueous GaN and ZnO Interfaces
NASA Astrophysics Data System (ADS)
Hybertsen, Mark S.; Kharche, Neerav; Muckerman, James T.
2014-03-01
Electronic energy level alignment at semiconductor-electrolyte interfaces is fundamental to electrochemical activity. Motivated in particular by the search for new materials that can be more efficient for photocatalysis, we develop a first principles method to calculate this alignment at aqueous interfaces and demonstrate it for the specific case of non-polar GaN and ZnO interfaces with water. In the first step, density functional theory (DFT) based molecular dynamics is used to sample the physical interface structure and to evaluate the electrostatic potential step at the interface. In the second step, the GW approach is used to evaluate the reference electronic energy level separately in the bulk semiconductor (valence band edge energy) and in bulk water (the 1b1 energy level), relative to the internal electrostatic energy reference. Use of the GW approach naturally corrects for errors inherent in the use of Kohn-Sham energy eigenvalues to approximate the electronic excitation energies in each material. With this predicted interface alignment, specific redox levels in water, with potentials known relative to the 1b1 level, can then be compared to the semiconductor band edge positions. Our results will be discussed in the context of experiments in which photoexcited GaN and ZnO drive the hydrogen evolution reaction. Research carried out at Brookhaven National Laboratory under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Gaylord, R F; Drake, J A; Gallagher, P J
2005-01-14
Chemistry and Materials Science Environmental Services (CES) is LLNL's on-site environmental analytical laboratory, analyzing approximately 2500 samples annually generally for waste characterization purposes. Due to the lack of process knowledge for analyzed samples, the waste produced by CES has traditionally been characterized on a ''worst-case'' basis as RCRA-hazardous mixed waste. By instituting rigorous ''up-front'' waste characterization, including segregation of acutely/extremely hazardous materials, utilizing regulatory exemptions, and developing a novel radiological characterization strategy, CES was able to receive approval for a certified LLW waste stream, adequately characterized for disposal at the Nevada Test Site. In the 10 months of operating history, CES has diverted 33% of its waste (by mass) from mixed to LLW. This will result in significant cost savings and reduction in waste re-handling/personnel exposure.
Kozorezov, A.G.; Wigmore, J.K.; Owens, A.; Hartog, R. den; Peacock, A.
2005-04-01
We report the development of a general analytic method for describing the responsivity and resolution for a pixellated semiconductor detector structure in terms of device and material properties. The method allows both drift and diffusive transport to be modelled, for which previously only Monte Carlo techniques have been available. We obtain a general solution, and show specific results for an array of square pixels, illustrating the device constraints required to optimize spatial and spectral resolution.
Ab initio potential energy surface and vibration-rotation energy levels of silicon dicarbide, SiC2.
Koput, Jacek
2016-10-05
The accurate ground-state potential energy surface of silicon dicarbide, SiC2 , has been determined from ab initio calculations using the coupled-cluster approach. Results obtained with the conventional and explicitly correlated coupled-cluster methods were compared. The core-electron correlation, higher-order valence-electron correlation, and scalar relativistic effects were taken into account. The potential energy barrier to the linear SiCC configuration was predicted to be 1782 cm(-1) . The vibration-rotation energy levels of the SiC2 , (29) SiC2 , (30) SiC2 , and SiC(13) C isotopologues were calculated using a variational method. The experimental vibration-rotation energy levels of the main isotopologue were reproduced to high accuracy. In particular, the experimental energy levels of the highly anharmonic vibrational ν3 mode of SiC2 were reproduced to within 6.7 cm(-1) , up to as high as the v3 = 16 state. © 2016 Wiley Periodicals, Inc.
Impact behaviour of Napier/polyester composites under different energy levels
NASA Astrophysics Data System (ADS)
Fahmi, I.; Majid, M. S. Abdul; Afendi, M.; Haslan, M.; Helmi E., A.; M. Haameem J., A.
2016-07-01
The effects of different energy levels on the impact behaviour of Napier fibre/polyester reinforced composites were investigated. Napier fibre was extracted using traditional water retting process to be utilized as reinforcing materials in polyester composite laminates. 25% fibre loading composite laminates were prepared and impacted at three different energy levels; 2.5,5 and 7.5 J using an instrumented drop weight impact testing machine (IMATEK IM10). The outcomes show that peak force and contact time increase with increased impact load. The energy absorption was then calculated from the force displacement curve. The results indicated that the energy absorption decreases with increasing energy levels of the impact. Impacted specimens were observed visually for fragmentation fracture using an optical camera to identify the failure mechanisms. Fracture fragmentation pattern from permanent dent to perforation with radial and circumferential was observed.
Impact behaviour of Napier/polyester composites under different energy levels
Fahmi, I. Majid, M. S. Abdul Afendi, M. Haameem, J. M.A.; Haslan, M. Helmi, E. A.
2016-07-19
The effects of different energy levels on the impact behaviour of Napier fibre/polyester reinforced composites were investigated. Napier fibre was extracted using traditional water retting process to be utilized as reinforcing materials in polyester composite laminates. 25% fibre loading composite laminates were prepared and impacted at three different energy levels; 2.5,5 and 7.5 J using an instrumented drop weight impact testing machine (IMATEK IM10). The outcomes show that peak force and contact time increase with increased impact load. The energy absorption was then calculated from the force displacement curve. The results indicated that the energy absorption decreases with increasing energy levels of the impact. Impacted specimens were observed visually for fragmentation fracture using an optical camera to identify the failure mechanisms. Fracture fragmentation pattern from permanent dent to perforation with radial and circumferential was observed.
NEW Fe I LEVEL ENERGIES AND LINE IDENTIFICATIONS FROM STELLAR SPECTRA
Peterson, Ruth C.; Kurucz, Robert L.
2015-01-01
The spectrum of the Fe I atom is critical to many areas of astrophysics and beyond. Measurements of the energies of its high-lying levels remain woefully incomplete, however, despite extensive laboratory and solar analysis. In this work, we use high-resolution archival absorption-line ultraviolet and optical spectra of stars whose warm temperatures favor moderate Fe I excitation. We derive the energy for a particular upper level in Kurucz's semiempirical calculations by adopting a trial value that yields the same wavelength for a given line predicted to be about as strong as that of a strong unidentified spectral line observed in the stellar spectra, then checking the new wavelengths of other strong predicted transitions that share the same upper level for coincidence with other strong observed unidentified lines. To date, this analysis has provided the upper energies of 66 Fe I levels. Many new energy levels are higher than those accessible to laboratory experiments; several exceed the Fe I ionization energy. These levels provide new identifications for over 2000 potentially detectable lines. Almost all of the new levels of odd parity include UV lines that were detected but unclassified in laboratory Fe I absorption spectra, providing an external check on the energy values. We motivate and present the procedure, provide the resulting new energy levels and their uncertainties, list all the potentially detectable UV and optical new Fe I line identifications and their gf values, point out new lines of astrophysical interest, and discuss the prospects for additional Fe I energy level determinations.
New Fe I Level Energies and Line Identifications from Stellar Spectra
NASA Astrophysics Data System (ADS)
Peterson, Ruth C.; Kurucz, Robert L.
2015-01-01
The spectrum of the Fe I atom is critical to many areas of astrophysics and beyond. Measurements of the energies of its high-lying levels remain woefully incomplete, however, despite extensive laboratory and solar analysis. In this work, we use high-resolution archival absorption-line ultraviolet and optical spectra of stars whose warm temperatures favor moderate Fe I excitation. We derive the energy for a particular upper level in Kurucz's semiempirical calculations by adopting a trial value that yields the same wavelength for a given line predicted to be about as strong as that of a strong unidentified spectral line observed in the stellar spectra, then checking the new wavelengths of other strong predicted transitions that share the same upper level for coincidence with other strong observed unidentified lines. To date, this analysis has provided the upper energies of 66 Fe I levels. Many new energy levels are higher than those accessible to laboratory experiments; several exceed the Fe I ionization energy. These levels provide new identifications for over 2000 potentially detectable lines. Almost all of the new levels of odd parity include UV lines that were detected but unclassified in laboratory Fe I absorption spectra, providing an external check on the energy values. We motivate and present the procedure, provide the resulting new energy levels and their uncertainties, list all the potentially detectable UV and optical new Fe I line identifications and their gf values, point out new lines of astrophysical interest, and discuss the prospects for additional Fe I energy level determinations.
NASA Astrophysics Data System (ADS)
Dorman, Lev; Zukerman, Igor
We describe the principles and operation of automated programs ``FEP-Research-1st Alert'', ``FEP-Research-2nd Alert'', and ``FEP-Research-3rd Alert''. The program ``FEP-Research-lst Alert'' gives preliminary determinations of the energy spectrum and flux at the beginning of an event on the basis of 1-minute data of total neutron intensity and intensities of different multiplicities in the neutron monitor (NM) at the Emilio Segre' Observatory (2025m above sea level, Rc = 10.8 GV) as well as available 1-minute on-line data in the near future of Cosmic Ray Observatories which collaborate with the Israel Cosmic Ray Center (Rome, Haleakala, Climax, Oulu, Moscow, Apatity, Mexico, Aragaz and others). Using well-known coupling functions for neutron monitors we have derived functions that relate the spectral index of flare energetic particles (FEP) to observations of multiplicities. We also derived important functions using ratios of FEP observations from the different cosmic ray monitors mentioned above. All these functions are approximated analytically with good accuracy and can be used for automatic realtime determination of the energy spectrum and fluxes of FEP. Using approximate values of the diffusion coefficient for the current level of solar activity as a function of particle energy, the program ``FEP-Research-1st Alert'' determines very roughly the expected level of radiation in space after (1)/(2), 1, (3)/(2) and 2 hours. If this level is expected to be dangerous for satellites and spacecrafts, the program ``FEP- Research-1st Alert'' sends preliminary 1st Alert. More accurate forecasts are given after 5-10 minutes by the program ``FEP-Research-2nd Alert'', and after 10-20 minutes program by the ``FEP-Research-3rd Alert'' using information on the diffusion coefficient obtained from on-line FEP ground data.
Effect of Femtosecond Laser Energy Level on Corneal Stromal Cell Death and Inflammation
de Medeiros, Fabricio Witzel; Kaur, Harmeet; Agrawal, Vandana; Chaurasia, Shyam S.; Hammel, Jefferey; Dupps, William J.; Wilson, Steven E.
2009-01-01
PURPOSE To analyze the effects of variations in femtosecond laser energy level on corneal stromal cell death and inflammatory cell influx following flap creation in a rabbit model. METHODS Eighteen rabbits were stratified in three different groups according to level of energy applied for flap creation (six animals per group). Three different energy levels were chosen for both the lamellar and side cut: 2.7 μJ (high energy), 1.6 μJ (intermediate energy), and 0.5 μJ (low energy) with a 60 KHz, model II, femtosecond laser (IntraLase). The opposite eye of each rabbit served as a control. At the 24-hour time point after surgery, all rabbits were euthanized and the corneoscleral rims were analyzed for the levels of cell death and inflammatory cell influx with the terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and immunocytochemistry for monocyte marker CD11b, respectively. RESULTS The high energy group (31.9±7.1 [standard error of mean (SEM) 2.9]) had significantly more TUNEL-positive cells in the central flap compared to the intermediate (22.2±1.9 [SEM 0.8], P=.004), low (17.9±4.0 [SEM 1.6], P≤.001), and control eye (0.06±0.02 [SEM 0.009], P≤.001) groups. The intermediate and low energy groups also had significantly more TUNEL-positive cells than the control groups (P≤.001). The difference between the intermediate and low energy levels was not significant (P=.56). The mean for CD11b-positive cells/400× field at the flap edge was 26.2±29.3 (SEM 12.0), 5.8±4.1 (SEM 1.7), 1.7±4.1 (SEM 1.7), and 0.0±0.0 (SEM 0.0) for high energy, intermediate energy, low energy, and control groups, respectively. Only the intermediate energy group showed statistically more inflammatory cells than control eyes (P=.015), most likely due to variability between eyes. CONCLUSIONS Higher energy levels trigger greater cell death when the femtosecond laser is used to create corneal flaps. Greater corneal inflammatory cell infiltration is observed
Bi-Level Decision Making for Supporting Energy and Water Nexus
NASA Astrophysics Data System (ADS)
Zhang, X.; Vesselinov, V. V.
2016-12-01
The inseparable relationship between energy production and water resources has led to the emerging energy-water nexus concept, which provides a means for integrated management and decision making of these two critical resources. However, the energy-water nexus frequently involves decision makers with different and competing management objectives. Furthermore, there is a challenge that decision makers and stakeholders might be making decisions sequentially from a higher level to a lower level, instead of at the same decision level, whereby the objective of a decision maker at a higher level should be satisfied first. In this study, a bi-level decision model is advanced to handle such decision-making situations for managing the energy-water nexus. The work represents a unique contribution to developing an integrated decision-support framework/tool to quantify and analyze the tradeoffs between the two-level energy-water nexus decision makers. Here, plans for electricity generation, fuel supply, water supply, capacity expansion of the power plants and environmental impacts are optimized to provide effective decision support. The developed decision-support framework is implemented in Julia (a high-level, high-performance dynamic programming language for technical computing) and is a part of the MADS (Model Analyses & Decision Support) framework (http://mads.lanl.gov). To demonstrate the capabilities of the developed methodology, a series of analyses are performed for synthetic problems consistent with actual real-world energy-water nexus management problems.
Building Energy Use Modeling at the U.S. State Level Under Climate Change
NASA Astrophysics Data System (ADS)
Zhou, Y.; Eom, J.; Clarke, L.; Kyle, P.
2012-12-01
Climate change plays an important role in building energy use for heating and cooling. As global building energy use accounts for as much as about 32% of global final energy consumption in 2005, the impact of climate change on greenhouse gas emissions may also be significant. As long-term socioeconomic transformation and energy service expansion show large spatial heterogeneity, advanced understanding of climate impact on building energy use at the sub-national level will offer useful insights into regional energy system planning. In this study, we have developed a detailed building energy model with U.S. 50-state representation, embedded in an integrated assessment framework (Global Change Assessment Model). The climate change impact on heating and cooling demand is measured through estimating heating and cooling degree days (HDD/CDDs) derived from MIT Integrated Global System Model (IGSM) climate data and linking the estimates to the building energy model. Having the model calibrated against historical data at the U.S. state level, we estimated the building energy use in the 21st century at the U.S. state level and analyzed its spatial pattern. We have found that the total building energy use (heating and cooling) in U.S. states is over- or under-estimated without having climate feedback taken into account, and that the difference with and without climate feedback at the state level varies from -25% to 25% in reference scenario and -15% to 10% in climate mitigation scenario. The result not only confirms earlier finding that global warming leads to increased cooling and decreased heating energy use, it also indicates that climate change has a different impact on total building energy use at national and state level, exhibiting large spatial heterogeneity across states (Figure 1). The scale impact in building energy use modeling emphasizes the importance of developing a building energy model that represents socioeconomic development, energy service expansion, and
Prusty, Sonali; Kundu, Shivlal Singh; Mondal, Goutam; Sontakke, Umesh; Sharma, Vijay Kumar
2016-04-01
To evaluate different levels of energy and protein for optimum growth of Murrah male buffalo calves, a growth trial (150 days) was conducted on 30 calves (body weight 202.5 ± 6.8 kg). Six diets were formulated to provide 90, 100 and 110% protein level and 90 and 110% energy level requirements for buffalo calves, derived from ICAR 2013 recommendations for buffaloes. The crude protein (CP) intake was increased with higher dietary CP, whereas no effect of energy levels or interaction between protein and energy was observed on CP intake. There were significant effects (P < 0.01) of the interaction between protein and energy (P < 0.05) on metabolizable energy (ME) intake. The digestibility of dry matter (DM), organic matter (OM) and non-fibrous carbohydrate (NFC) was higher (P < 0.0001) in high-energy groups compared to low-energy groups. The CP digestibility increased with the increased CP and ME of the rations. The absorbed N was improved linearly with an increased level of dietary CP, whereas the N retention was similar among all the groups distributed as per different energy or protein levels. The nutrient intake (protein or energy) per kg body weight (BW)(0.75) at various fortnight intervals was regressed linearly from the average daily gain (ADG) per kg BW(0.75). By setting the average daily gain at zero in the developed regression equation, a maintenance requirement was obtained, i.e. 133.1 kcal ME, 6.45 g CP and 3.95 g metabolizable protein (MP) per kg BW(0.75). Requirement for growth was 6.12 kcal ME, 0.46 g CP and 0.32 g MP per kg BW(0.75) per day. Metabolizable amino acid requirement was estimated from partitioning of MP intake and ADG. The ME requirements were lower, whereas the MP requirement of Murrah buffaloes was higher than ICAR (2013) recommendations.
2016-01-01
We introduce a new class of methods, denoted as Truncated Conjugate Gradient(TCG), to solve the many-body polarization energy and its associated forces in molecular simulations (i.e. molecular dynamics (MD) and Monte Carlo). The method consists in a fixed number of Conjugate Gradient (CG) iterations. TCG approaches provide a scalable solution to the polarization problem at a user-chosen cost and a corresponding optimal accuracy. The optimality of the CG-method guarantees that the number of the required matrix-vector products are reduced to a minimum compared to other iterative methods. This family of methods is non-empirical, fully adaptive, and provides analytical gradients, avoiding therefore any energy drift in MD as compared to popular iterative solvers. Besides speed, one great advantage of this class of approximate methods is that their accuracy is systematically improvable. Indeed, as the CG-method is a Krylov subspace method, the associated error is monotonically reduced at each iteration. On top of that, two improvements can be proposed at virtually no cost: (i) the use of preconditioners can be employed, which leads to the Truncated Preconditioned Conjugate Gradient (TPCG); (ii) since the residual of the final step of the CG-method is available, one additional Picard fixed point iteration (“peek”), equivalent to one step of Jacobi Over Relaxation (JOR) with relaxation parameter ω, can be made at almost no cost. This method is denoted by TCG-n(ω). Black-box adaptive methods to find good choices of ω are provided and discussed. Results show that TPCG-3(ω) is converged to high accuracy (a few kcal/mol) for various types of systems including proteins and highly charged systems at the fixed cost of four matrix-vector products: three CG iterations plus the initial CG descent direction. Alternatively, T(P)CG-2(ω) provides robust results at a reduced cost (three matrix-vector products) and offers new perspectives for long polarizable MD as a production
Olsson, Martin A; Söderhjelm, Pär; Ryde, Ulf
2016-06-30
In this article, the convergence of quantum mechanical (QM) free-energy simulations based on molecular dynamics simulations at the molecular mechanics (MM) level has been investigated. We have estimated relative free energies for the binding of nine cyclic carboxylate ligands to the octa-acid deep-cavity host, including the host, the ligand, and all water molecules within 4.5 Å of the ligand in the QM calculations (158-224 atoms). We use single-step exponential averaging (ssEA) and the non-Boltzmann Bennett acceptance ratio (NBB) methods to estimate QM/MM free energy with the semi-empirical PM6-DH2X method, both based on interaction energies. We show that ssEA with cumulant expansion gives a better convergence and uses half as many QM calculations as NBB, although the two methods give consistent results. With 720,000 QM calculations per transformation, QM/MM free-energy estimates with a precision of 1 kJ/mol can be obtained for all eight relative energies with ssEA, showing that this approach can be used to calculate converged QM/MM binding free energies for realistic systems and large QM partitions. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.
Energy level of the nitrogen dangling bond in amorphous silicon nitride
Warren, W.L. ); Kanicki, J. ); Robertson, J. ); Lenahan, P.M. )
1991-09-30
The composition dependence and room-temperature metastability of the paramagnetic nitrogen dangling-bond center is amorphous silicon nitride suggest that its energy level lies close to the N {ital p}{pi} states, in agreement with theoretical calculations.
Experimental Energy Levels and Partition Function of the 12C2 Molecule
NASA Astrophysics Data System (ADS)
Furtenbacher, Tibor; Szabó, István; Császár, Attila G.; Bernath, Peter F.; Yurchenko, Sergei N.; Tennyson, Jonathan
2016-06-01
The carbon dimer, the 12C2 molecule, is ubiquitous in astronomical environments. Experimental-quality rovibronic energy levels are reported for 12C2, based on rovibronic transitions measured for and among its singlet, triplet, and quintet electronic states, reported in 42 publications. The determination utilizes the Measured Active Rotational-Vibrational Energy Levels (MARVEL) technique. The 23,343 transitions measured experimentally and validated within this study determine 5699 rovibronic energy levels, 1325, 4309, and 65 levels for the singlet, triplet, and quintet states investigated, respectively. The MARVEL analysis provides rovibronic energies for six singlet, six triplet, and two quintet electronic states. For example, the lowest measurable energy level of the {{a}}{}3{{{\\Pi }}}{{u}} state, corresponding to the J = 2 total angular momentum quantum number and the F 1 spin-multiplet component, is 603.817(5) cm-1. This well-determined energy difference should facilitate observations of singlet-triplet intercombination lines, which are thought to occur in the interstellar medium and comets. The large number of highly accurate and clearly labeled transitions that can be derived by combining MARVEL energy levels with computed temperature-dependent intensities should help a number of astrophysical observations as well as corresponding laboratory measurements. The experimental rovibronic energy levels, augmented, where needed, with ab initio variational ones based on empirically adjusted and spin-orbit coupled potential energy curves obtained using the Duo code, are used to obtain a highly accurate partition function, and related thermodynamic data, for 12C2 up to 4000 K.
Briggs, Marc A.; Cockburn, Emma; Rumbold, Penny L. S.; Rae, Glen; Stevenson, Emma J.; Russell, Mark
2015-01-01
This study investigated the energy intake and expenditure of professional adolescent academy-level soccer players during a competitive week. Over a seven day period that included four training days, two rest days and a match day, energy intake (self-reported weighed food diary and 24-h recall) and expenditure (tri-axial accelerometry) were recorded in 10 male players from a professional English Premier League club. The mean macronutrient composition of the dietary intake was 318 ± 24 g·day−1 (5.6 ± 0.4 g·kg−1 BM) carbohydrate, 86 ± 10 g·day−1 (1.5 ± 0.2 g·kg−1 BM) protein and 70 ± 7 g·day−1 (1.2 ± 0.1 g·kg−1 BM) fats, representing 55% ± 3%, 16% ± 1%, and 29% ± 2% of mean daily energy intake respectively. A mean daily energy deficit of −1302 ± 1662 kJ (p = 0.035) was observed between energy intake (9395 ± 1344 kJ) and energy expenditure (10679 ± 1026 kJ). Match days (−2278 ± 2307 kJ, p = 0.012) and heavy training days (−2114 ± 2257 kJ, p = 0.016) elicited the greatest deficits between intake and expenditure. In conclusion, the mean daily energy intake of professional adolescent academy-level soccer players was lower than the energy expended during a competitive week. The magnitudes of these deficits were greatest on match and heavy training days. These findings may have both short and long term implications on the performance and physical development of adolescent soccer players. PMID:26445059
Briggs, Marc A; Cockburn, Emma; Rumbold, Penny L S; Rae, Glen; Stevenson, Emma J; Russell, Mark
2015-10-02
This study investigated the energy intake and expenditure of professional adolescent academy-level soccer players during a competitive week. Over a seven day period that included four training days, two rest days and a match day, energy intake (self-reported weighed food diary and 24-h recall) and expenditure (tri-axial accelerometry) were recorded in 10 male players from a professional English Premier League club. The mean macronutrient composition of the dietary intake was 318 ± 24 g·day(-1) (5.6 ± 0.4 g·kg(-1) BM) carbohydrate, 86 ± 10 g·day(-1) (1.5 ± 0.2 g·kg(-1) BM) protein and 70 ± 7 g·day(-1) (1.2 ± 0.1 g·kg(-1) BM) fats, representing 55% ± 3%, 16% ± 1%, and 29% ± 2% of mean daily energy intake respectively. A mean daily energy deficit of -1302 ± 1662 kJ (p = 0.035) was observed between energy intake (9395 ± 1344 kJ) and energy expenditure (10679 ± 1026 kJ). Match days (-2278 ± 2307 kJ, p = 0.012) and heavy training days (-2114 ± 2257 kJ, p = 0.016) elicited the greatest deficits between intake and expenditure. In conclusion, the mean daily energy intake of professional adolescent academy-level soccer players was lower than the energy expended during a competitive week. The magnitudes of these deficits were greatest on match and heavy training days. These findings may have both short and long term implications on the performance and physical development of adolescent soccer players.
van Hoeij, R J; Dijkstra, J; Bruckmaier, R M; Gross, J J; Lam, T J G M; Remmelink, G J; Kemp, B; van Knegsel, A T M
2017-10-01
Omitting the dry period (DP) generally reduces milk production in the subsequent lactation. The aim of this study was to evaluate the effect of dietary energy source-glucogenic (G) or lipogenic (L)-and energy level-standard (std) or low-on milk production; energy balance (EB); lactogenic hormones insulin, insulin-like growth factor 1 (IGF-1), and growth hormone (GH); and lactation curve characteristics between wk 1 and 44 postpartum in cows after a 0-d or 30-d DP. Cows (n = 110) were assigned randomly to 3 transition treatments: a 30-d DP with a standard energy level required for expected milk yield [30-d DP(std)], a 0-d DP with the same energy level as cows with a 30-d DP [0-d DP(std)], and a 0-d DP with a low energy level [0-d DP(low)]. In wk 1 to 7, cows were fed the same basal ration but the level of concentrate increased to 6.7 kg/d for cows fed the low energy level and to 8.5 kg/d for cows fed the standard energy level in wk 4. From wk 8 postpartum onward, cows received a G ration (mainly consisting of corn silage and grass silage) or an L ration (mainly consisting of grass silage and sugar beet pulp) with the same energy level contrast (low or std) as in early lactation. Cows fed the G ration had greater milk, lactose, and protein yields, lower milk fat percentage, greater dry matter and energy intakes, and greater plasma IGF-1 concentration compared with cows fed the L ration. Dietary energy source did not affect EB or lactation curve characteristics. In cows with a 0-d DP, the reduced energy level decreased energy intake, EB, and weekly body weight gain, but did not affect milk production or lactation curve characteristics. A 30-d DP resulted in a greater total predicted lactation yield, initial milk yield after calving, peak milk yield, energy intake, energy output in milk, days to conception [only when compared with 0-d DP(low)], plasma GH concentration [only when compared with 0-d DP(std)], and decreased weekly body weight gain compared with a 0-d DP. A
Suppressing recombination in polymer photovoltaic devices via energy-level cascades.
Tan, Zhi-Kuang; Johnson, Kerr; Vaynzof, Yana; Bakulin, Artem A; Chua, Lay-Lay; Ho, Peter K H; Friend, Richard H
2013-08-14
An energy cascading structure is designed in a polymer photovoltaic device to suppress recombination and improve quantum yields. By the insertion of a thin polymer interlayer with intermediate energy levels, electrons and holes can effectively shuttle away from each other while being spatially separated from recombination. An increase in open-circuit voltage and short-circuit current are observed in modified devices.
Role of energy-level mismatches in a multi-pathway complex of photosynthesis
NASA Astrophysics Data System (ADS)
Lim, James; Ryu, Junghee; Lee, Changhyoup; Yoo, Seokwon; Jeong, Hyunseok; Lee, Jinhyoung
2011-10-01
Considering a multi-pathway structure in a light-harvesting complex of photosynthesis, we investigated the role of energy-level mismatches between antenna molecules in transferring the absorbed energy to a reaction center (RC). We found a condition in which the antenna molecules faithfully play their roles: when their effective absorption ratios are larger than those of the receiver molecule directly coupled to the RC. In the absence of energy-level mismatches and dephasing noise, there arises quantum destructive interference between multiple paths that restricts the energy transfer. On the other hand, the destructive interference diminishes as asymmetrically biasing the energy-level mismatches and/or introducing quantum noise of dephasing for the antenna molecules, so that the transfer efficiency is greatly enhanced to nearly unity. Remarkably, the near-unity efficiency can be achieved at a wide range of asymmetric energy-level mismatches. Temporal characteristics are also optimized at the energy-level mismatches where the transfer efficiency is nearly unity. We discuss these effects, in particular, for the Fenna-Matthews-Olson complex.
Opitz, Andreas
2017-04-05
Planar organic heterojunctions are widely used in photovoltaic cells, light-emitting diodes, and bilayer field-effect transistors. The energy level alignment in the devices plays an important role in obtaining the aspired gap arrangement. Additionally, the π-orbital overlap between the involved molecules defines e.g. the charge-separation efficiency in solar cells due to charge-transfer effects. To account for both aspects, direct/inverse photoemission spectroscopy and near edge x-ray absorption fine structure spectroscopy were used to determine the energy level landscape and the molecular orientation at prototypical planar organic heterojunctions. The combined experimental approach results in a comprehensive model for the electronic and morphological characteristics of the interface between the two investigated molecular semiconductors. Following an introduction on heterojunctions used in devices and on energy levels of organic materials, the energy level alignment of planar organic heterojunctions will be discussed. The observed energy landscape is always determined by the individual arrangement between the energy levels of the molecules and the work function of the electrode. This might result in contact doping due to Fermi level pinning at the electrode for donor/acceptor heterojunctions, which also improves the solar cell efficiency. This pinning behaviour can be observed across an unpinned interlayer and results in charge accumulation at the donor/acceptor interface, depending on the transport levels of the respective organic semiconductors. Moreover, molecular orientation will affect the energy levels because of the anisotropy in ionisation energy and electron affinity and is influenced by the structural compatibility of the involved molecules at the heterojunction. High structural compatibility leads to π-orbital stacking between different molecules at a heterojunction, which is of additional interest for photovoltaic active interfaces and for ground
NASA Astrophysics Data System (ADS)
Opitz, Andreas
2017-04-01
Planar organic heterojunctions are widely used in photovoltaic cells, light-emitting diodes, and bilayer field-effect transistors. The energy level alignment in the devices plays an important role in obtaining the aspired gap arrangement. Additionally, the π-orbital overlap between the involved molecules defines e.g. the charge-separation efficiency in solar cells due to charge-transfer effects. To account for both aspects, direct/inverse photoemission spectroscopy and near edge x-ray absorption fine structure spectroscopy were used to determine the energy level landscape and the molecular orientation at prototypical planar organic heterojunctions. The combined experimental approach results in a comprehensive model for the electronic and morphological characteristics of the interface between the two investigated molecular semiconductors. Following an introduction on heterojunctions used in devices and on energy levels of organic materials, the energy level alignment of planar organic heterojunctions will be discussed. The observed energy landscape is always determined by the individual arrangement between the energy levels of the molecules and the work function of the electrode. This might result in contact doping due to Fermi level pinning at the electrode for donor/acceptor heterojunctions, which also improves the solar cell efficiency. This pinning behaviour can be observed across an unpinned interlayer and results in charge accumulation at the donor/acceptor interface, depending on the transport levels of the respective organic semiconductors. Moreover, molecular orientation will affect the energy levels because of the anisotropy in ionisation energy and electron affinity and is influenced by the structural compatibility of the involved molecules at the heterojunction. High structural compatibility leads to π-orbital stacking between different molecules at a heterojunction, which is of additional interest for photovoltaic active interfaces and for ground
Levelized Cost of Energy Analysis of Marine and Hydrokinetic Reference Models: Preprint
Jenne, D. S.; Yu, Y. H.; Neary, V.
2015-04-24
In 2010 the U.S. Department of Energy initiated the development of six marine energy converter reference models. The reference models are point designs of well-known marine energy converters. Each device was designed to operate in a specific marine resource, instead of a generic device that can be deployed at any location. This method allows each device to be used as a benchmark for future reference model to benchmark future devices. The six designs consist of three current energy converters and three wave energy converters. The reference model project has generated both technical and economic data sets that are available in the public domain. The methodology to calculate the levelized cost of energy for the reference model project and an overall comparison of the cost of energy from these six reference-model designs are presented in this paper.
Allen, Chiharu S.; Chen, Qi; Willson, Victor L.; Hughes, Jan N.
2010-01-01
The present meta-analysis examined the effect of grade retention on academic outcomes and investigated systemic sources of variability in effect sizes. Using multi-level modeling, we investigated characteristics of 207 effect sizes across 22 studies published between 1990 and 2007 at two levels: the study (between) and individual (within) levels. Design quality was a study-level variable. Individual level variables were median grade retained and median number of years post retention. Quality of design was associated with less negative effects. Studies employing middle to high methodological designs yielded effect sizes not statistically significantly different from zero and 0.34 higher (more positive) than studies with low design quality. Years post retention was negatively associated with retention effects, and this effect was stronger for studies using grade comparisons versus age comparisons. Results challenge the widely held view that retention has a negative impact on achievement. Suggestions for future research are discussed. PMID:20717492
NASA Astrophysics Data System (ADS)
Saloman, Edward B.; Kramida, Alexander
2017-08-01
The energy levels, observed spectral lines, and transition probabilities of singly ionized vanadium, V ii, have been compiled. The experimentally derived energy levels belong to the configurations 3d 4, 3d 3 ns (n = 4, 5, 6), 3d 3 np, and 3d 3 nd (n = 4, 5), 3d 34f, 3d 24s 2, and 3d 24s4p. Also included are values for some forbidden lines that may be of interest to the astrophysical community. Experimental Landé g-factors and leading percentages for the levels are included when available, as well as Ritz wavelengths calculated from the energy levels. Wavelengths and transition probabilities are reported for 3568 and 1896 transitions, respectively. From the list of observed wavelengths, 407 energy levels are determined. The observed intensities, normalized to a common scale, are provided. From the newly optimized energy levels, a revised value for the ionization energy is derived, 118,030(60) cm-1, corresponding to 14.634(7) eV. This is 130 cm-1 higher than the previously recommended value from Iglesias et al.
NASA Astrophysics Data System (ADS)
Brancati, Renato; Strano, Salvatore; Timpone, Francesco
2011-10-01
When in use, a tire dissipates energy according to various mechanisms: rolling resistance, viscosity, hysteresis, friction energy, etc. This dissipation of energy contributes to influencing tire temperature, contact conditions and the resulting friction coefficient. This research project deals with viscoelastic and hysteretic mechanisms, and presents an explicit expression of the energy dissipated by tire-road interactions caused by these mechanisms. It is based on the Dahl model with regard to the hysteretic force together with a spring and a frequency variable damping coefficient with regard to the viscoelastic one. The energy expression found in this way can be used in tire thermal models to determine one of the heat flows needed to estimate the contact temperature and to find out the actual friction coefficient to be used in real time tire-road interaction models. Experimental tests were carried out, for longitudinal interaction only, in order to evaluate the effectiveness of the proposed expression by identifying the parameters and validating the results.
Growth and energy budget of juvenile lenok Brachymystax lenok in relation to ration level
NASA Astrophysics Data System (ADS)
Liu, Yang; Li, Zhongjie; Zhang, Tanglin; Yuan, Jing; Mou, Zhenbo; Liu, Jiashou
2015-03-01
We evaluated the effect of ration level (RL) on the growth and energy budget of lenok Brachymystax lenok. Juvenile lenok (initial mean body weight 3.06±0.13 g) were fed for 21 d at five different ration levels: starvation, 2%, 3%, 4% bwd (body weight per day, based on initial mean values), and apparent satiation. Feed consumption, apparent digestibility, and growth were directly measured. Specific growth rates in terms of wet weight, dry weight, protein, and energy increased logarithmically with an increase in ration levels. The relationship between specific growth rate in terms of wet weight (SGRw, %/d) and RL (%) was characterized by a decelerating curve: SGRw=-1.417+3.166ln(RL+1). The apparent digestibility coefficients of energy exhibited a decreasing pattern with increasing ration level, and there was a significant difference among different RLs. Body composition was significantly affected by ration size. The relationship between feed efficiency rate in terms of energy (FERe) and RL was: FERe=-14.167+23.793RL-3.367(RL)2, and the maximum FERe was observed at a 3.53% ration. The maintenance requirement for energy of juvenile lenok was 105.39 kJ BW (kg)-0.80/d, the utilization efficiency of DE for growth was 0.496. The energy budget equation at satiation was: 100IE=29.03FE+5.78(ZE+UE)+39.56 HE+25.63 RE, where IE is feed energy, FE is fecal energy, ZE+UE is excretory energy, HE is heat production, and RE is recovered energy. Our results suggest that the most suitable feeding rate for juvenile lenok aquaculture for wet weight growth is 2.89% bwd, whereas for energy growth, the suggested rate is 3.53% bwd at this growth stage.
Ramirez-Boo, María; Garrido, Juan J; Ogueta, Samuel; Calvete, Juan J; Gómez-Díaz, Consuelo; Moreno, Angela
2006-04-01
In this paper, we present the protein map corresponding to the porcine peripheral blood mononuclear cells (PBMC) to better understand the role of these cells in the pig immune system. To conform the map, the proteins were separated by 2-DE using a 5-8 range pH gradient in IEF and approximately 800 spots were detected. Due to the high level of indeterminate variability associates to the 2-DE, analytical and biological variances were analyzed. The analytical variance was calculated for 50 proteins in three replicate 2-DE gels from the same protein extract whereas the biological variance was determined by comparison of the patterns obtained for the same 50 proteins in different animals. Values of 15.13 and 33.70% were determined for analytical and biological variances, respectively. These average variances will provide a quantified and statistical basis for future proteomic studies directed to evaluate relevant quantitative changes in the biological response. A representative set of the major proteins was subjected to MALDI-TOF analysis and over 75% of the proteins were identified on the basis of their similarity with its human homologue proteins. A large number of cytoskeletal and metabolic proteins were found as well as some proteins related to cell mobility and immunological functions. Finally, other proteins implicated in the cell signaling process, transport or apoptosis were also identified giving a wide overview of the porcine PBMC protein map.
Chemical control over the energy-level alignment in a two-terminal junction.
Yuan, Li; Franco, Carlos; Crivillers, Núria; Mas-Torrent, Marta; Cao, Liang; Sangeeth, C S Suchand; Rovira, Concepció; Veciana, Jaume; Nijhuis, Christian A
2016-07-26
The energy-level alignment of molecular transistors can be controlled by external gating to move molecular orbitals with respect to the Fermi levels of the source and drain electrodes. Two-terminal molecular tunnelling junctions, however, lack a gate electrode and suffer from Fermi-level pinning, making it difficult to control the energy-level alignment of the system. Here we report an enhancement of 2 orders of magnitude of the tunnelling current in a two-terminal junction via chemical molecular orbital control, changing chemically the molecular component between a stable radical and its non-radical form without altering the supramolecular structure of the junction. Our findings demonstrate that the energy-level alignment in self-assembled monolayer-based junctions can be regulated by purely chemical modifications, which seems an attractive alternative to control the electrical properties of two-terminal junctions.
Chemical control over the energy-level alignment in a two-terminal junction
Yuan, Li; Franco, Carlos; Crivillers, Núria; Mas-Torrent, Marta; Cao, Liang; Sangeeth, C. S. Suchand; Rovira, Concepció; Veciana, Jaume; Nijhuis, Christian A.
2016-01-01
The energy-level alignment of molecular transistors can be controlled by external gating to move molecular orbitals with respect to the Fermi levels of the source and drain electrodes. Two-terminal molecular tunnelling junctions, however, lack a gate electrode and suffer from Fermi-level pinning, making it difficult to control the energy-level alignment of the system. Here we report an enhancement of 2 orders of magnitude of the tunnelling current in a two-terminal junction via chemical molecular orbital control, changing chemically the molecular component between a stable radical and its non-radical form without altering the supramolecular structure of the junction. Our findings demonstrate that the energy-level alignment in self-assembled monolayer-based junctions can be regulated by purely chemical modifications, which seems an attractive alternative to control the electrical properties of two-terminal junctions. PMID:27456200
Energy level alignment between C 60 and Al using ultraviolet photoelectron spectroscopy
NASA Astrophysics Data System (ADS)
Seo, J. H.; Kang, S. J.; Kim, C. Y.; Cho, S. W.; Yoo, K.-H.; Whang, C. N.
2006-09-01
The energy level alignment between C 60 and Al has been investigated by using ultraviolet photoelectron spectroscopy. To obtain the interfacial electronic structure between C 60 and Al, C 60 was deposited on a clean Al substrate in a stepwise manner. The valence-band spectra were measured immediately after each step of C 60 deposition without breaking the vacuum. The measured onset of the highest occupied molecular orbital energy level was located at 1.59 eV from the Fermi level of Al. The vacuum level was shifted 0.68 eV toward lower binding energy with additional C 60 layers. The observed vacuum level shift means that the interface dipole exists at the interface between C 60 and Al. The barrier height of electron injection from Al to C 60 is 0.11 eV, which is smaller value than that of hole injection.
The energy levels and transition properties of In-like ions
NASA Astrophysics Data System (ADS)
Wang, H.-W.; Zhang, L.; Jiang, G.; Li, X.-F.; Wang, H.-B.
2017-08-01
The energy levels and transition properties of In-like ions are investigated by using the multi-configuration Dirac-Hartree-Fock method. The results for the energy levels, transition probabilities, wavelengths, line strengths and lifetimes of In-like Cs VII—Pm XIII are reported. Relativistic effects and electron correlation are included. Our calculations agree well with the experimental and other theoretical values. The new data of energy levels and transition parameters are predicted. The level crossing happens between the configurations 5s 24f and 5s 25p with increasing nuclear charge. The transition frequencies are within the range of usual lasers because of the level crossing. In-like ions may be developed into atomic clock.
Energy levels of an ideal quantum ring in AA-stacked bilayer graphene
NASA Astrophysics Data System (ADS)
Zahidi, Youness; Belouad, Abdelhadi; Jellal, Ahmed
2017-05-01
We theoretically analyze the energy spectrum of a quantum ring in AA-stacked bilayer graphene with radius R for a zero width subjected to a perpendicular magnetic field B. An analytical approach, using the Dirac equation, is implemented to obtain the energy spectrum by freezing out the carrier radial motion. The obtained spectrum exhibits different symmetries and for a fixed total angular momentum m, it has a hyperbolic dependence of the magnetic field. In particular, the energy spectra are not invariant under the transformation B\\longrightarrow - B . The application of a potential, on the upper and lower layer, allows us to open a gap in the energy spectrum and the application of a non zero magnetic field breaks all symmetries. We also analyze the basic features of the energy spectrum to show the main similarities and differences with respect to an ideal quantum ring in monolayer, AB-stacked bilayer graphene and a quantum ring with finite width in AB-stacked bilayer graphene.
Energy-Water Nexus: Balancing the Tradeoffs between Two-Level Decision Makers
Zhang, Xiaodong; Vesselinov, Velimir Valentinov
2016-09-03
Energy-water nexus has substantially increased importance in the recent years. Synergistic approaches based on systems-analysis and mathematical models are critical for helping decision makers better understand the interrelationships and tradeoffs between energy and water. In energywater nexus management, various decision makers with different goals and preferences, which are often conflicting, are involved. These decision makers may have different controlling power over the management objectives and the decisions. They make decisions sequentially from the upper level to the lower level, challenging decision making in energy-water nexus. In order to address such planning issues, a bi-level decision model is developed, which improves upon the existing studies by integration of bi-level programming into energy-water nexus management. The developed model represents a methodological contribution to the challenge of sequential decisionmaking in energy-water nexus through provision of an integrated modeling framework/tool. An interactive fuzzy optimization methodology is introduced to seek a satisfactory solution to meet the overall satisfaction of the two-level decision makers. The tradeoffs between the two-level decision makers in energy-water nexus management are effectively addressed and quantified. Application of the proposed model to a synthetic example problem has demonstrated its applicability in practical energy-water nexus management. Optimal solutions for electricity generation, fuel supply, water supply including groundwater, surface water and recycled water, capacity expansion of the power plants, and GHG emission control are generated. In conclusion, these analyses are capable of helping decision makers or stakeholders adjust their tolerances to make informed decisions to achieve the overall satisfaction of energy-water nexus management where bi-level sequential decision making process is involved.
Energy-Water Nexus: Balancing the Tradeoffs between Two-Level Decision Makers
Zhang, Xiaodong; Vesselinov, Velimir Valentinov
2016-09-03
Energy-water nexus has substantially increased importance in the recent years. Synergistic approaches based on systems-analysis and mathematical models are critical for helping decision makers better understand the interrelationships and tradeoffs between energy and water. In energywater nexus management, various decision makers with different goals and preferences, which are often conflicting, are involved. These decision makers may have different controlling power over the management objectives and the decisions. They make decisions sequentially from the upper level to the lower level, challenging decision making in energy-water nexus. In order to address such planning issues, a bi-level decision model is developed, which improvesmore » upon the existing studies by integration of bi-level programming into energy-water nexus management. The developed model represents a methodological contribution to the challenge of sequential decisionmaking in energy-water nexus through provision of an integrated modeling framework/tool. An interactive fuzzy optimization methodology is introduced to seek a satisfactory solution to meet the overall satisfaction of the two-level decision makers. The tradeoffs between the two-level decision makers in energy-water nexus management are effectively addressed and quantified. Application of the proposed model to a synthetic example problem has demonstrated its applicability in practical energy-water nexus management. Optimal solutions for electricity generation, fuel supply, water supply including groundwater, surface water and recycled water, capacity expansion of the power plants, and GHG emission control are generated. In conclusion, these analyses are capable of helping decision makers or stakeholders adjust their tolerances to make informed decisions to achieve the overall satisfaction of energy-water nexus management where bi-level sequential decision making process is involved.« less
Energy-Water Nexus: Balancing the Tradeoffs between Two-Level Decision Makers
Zhang, Xiaodong; Vesselinov, Velimir Valentinov
2016-09-03
Energy-water nexus has substantially increased importance in the recent years. Synergistic approaches based on systems-analysis and mathematical models are critical for helping decision makers better understand the interrelationships and tradeoffs between energy and water. In energywater nexus management, various decision makers with different goals and preferences, which are often conflicting, are involved. These decision makers may have different controlling power over the management objectives and the decisions. They make decisions sequentially from the upper level to the lower level, challenging decision making in energy-water nexus. In order to address such planning issues, a bi-level decision model is developed, which improves upon the existing studies by integration of bi-level programming into energy-water nexus management. The developed model represents a methodological contribution to the challenge of sequential decisionmaking in energy-water nexus through provision of an integrated modeling framework/tool. An interactive fuzzy optimization methodology is introduced to seek a satisfactory solution to meet the overall satisfaction of the two-level decision makers. The tradeoffs between the two-level decision makers in energy-water nexus management are effectively addressed and quantified. Application of the proposed model to a synthetic example problem has demonstrated its applicability in practical energy-water nexus management. Optimal solutions for electricity generation, fuel supply, water supply including groundwater, surface water and recycled water, capacity expansion of the power plants, and GHG emission control are generated. In conclusion, these analyses are capable of helping decision makers or stakeholders adjust their tolerances to make informed decisions to achieve the overall satisfaction of energy-water nexus management where bi-level sequential decision making process is involved.
Fiore, R.; Papa, A.; Jenkovszky, L.L.; Kotikov, A.V.; Paccanoni, F.; Predazzi, E.
2005-02-01
In this paper we present an analytic result for the evolution in Q{sup 2} of the structure functions for the neutrino-nucleon interaction, valid at twist-2 in the region of small values of the Bjorken x variable and for soft nonperturbative input. In the special case of flat initial conditions, we include in the calculation also the contribution of the twist-4 gluon recombination corrections, whose effect in the evolution is explicitly determined. Finally, we estimate the resulting charged-current neutrino-nucleon total cross section and discuss its behavior at ultrahigh energies.
Energy Levels and Half-Lives of Gallium Isotopes Obtained by Photo-Nuclear Reaction
NASA Astrophysics Data System (ADS)
Dulger, F.; Akkoyun, S.; Bayram, T.; Dapo, H.; Boztosun, I.
2015-04-01
We have run an experiment to determine the energy levels and half-lives of Gallium nucleus by using the photonuclear reactions with end-point energy of 18 MeV bremsstrahlung photons, produced by a clinical linear accelerator. As a result of 71Ga(y,n)70Ga and 69Ga(Y,n)68Ga photonuclear reactions, the energy levels and half-lives of 70Ga and 68Ga nuclei have been determined. The results are in good agreement with the literature values.
Energy-level alignment at interfaces between manganese phthalocyanine and C60
Rückerl, Florian; Büchner, Bernd
2017-01-01
We have used photoelectron spectroscopy to determine the energy-level alignment at organic heterojunctions made of manganese phthalocyanine (MnPc) and the fullerene C60. We show that this energy-level alignment depends upon the preparation sequence, which is explained by different molecular orientations. Moreover, our results demonstrate that MnPc/C60 interfaces are hardly suited for application in organic photovoltaic devices, since the energy difference of the two lowest unoccupied molecular orbitals (LUMOs) is rather small. PMID:28546887
Nogami, Keisuke; Sakai, Yasuhiro; Mineta, Shota; Kato, Daiji; Murakami, Izumi; Sakaue, Hiroyuki A.; Kenmotsu, Takahiro; Furuya, Kenji; Motohashi, Kenji
2015-11-15
Visible emission spectra were acquired from neutral atoms sputtered by 35–60 keV Kr{sup +} ions from a polycrystalline tungsten surface. Mean velocities of excited tungsten atoms in seven different 6p states were also obtained via the dependence of photon intensities on the distance from the surface. The average velocities parallel to the surface normal varied by factors of 2–4 for atoms in the different 6p energy levels. However, they were almost independent of the incident ion kinetic energy. The 6p-level energy dependence indicated that the velocities of the excited atoms were determined by inelastic processes that involve resonant charge exchange.
Spectrum and energy levels of five-times ionized zirconium (Zr VI)
NASA Astrophysics Data System (ADS)
Reader, Joseph; Lindsay, Mark D.
2016-02-01
We carried out a new analysis of the spectrum of five-times-ionized zirconium Zr VI. For this we used sliding-spark discharges together with normal- and grazing-incidence spectrographs to observe the spectrum from 160 to 2000 Å. These observations showed that the analysis of this spectrum by Khan et al (1985 Phys. Scr. 31 837) contained a significant number of incorrect energy levels. We have now classified ˜420 lines as transitions between 23 even-parity levels 73 odd-parity levels. The 4s24p5, 4s4p6, 4s24p44d, 5s, 5d, 6s configurations are now complete, although a few levels of 4s24p45d are tentative. We determined Ritz-type wavelengths for ˜135 lines from the optimized energy levels. The uncertainties range from 0.0003 to 0.0020 Å. Hartree-Fock calculations and least-squares fits of the energy parameters to the observed levels were used to interpret the observed configurations. Oscillator strengths for all classified lines were calculated with the fitted parameters. The results are compared with values for the level energies, percentage compositions, and transition probabilities from recent ab initio theoretical calculations. The ionization energy was revised to 777 380 ± 300 cm-1 (96.38 ± 0.04 eV).
Low Levels of Energy Expenditure in Childhood Cancer Survivors: Implications for Obesity Prevention.
Zhang, Fang Fang; Roberts, Susan B; Parsons, Susan K; Must, Aviva; Kelly, Michael J; Wong, William W; Saltzman, Edward
2015-04-01
Childhood cancer survivors are at an increased risk of obesity but causes for this elevated risk are uncertain. We evaluated total energy expenditure in childhood cancer survivors using the doubly labeled water method in a cross-sectional study of 17 survivors of pediatric leukemia or lymphoma (median age, 11.5 y). Mean total energy expenditure was 2073 kcal/d, which was nearly 500 kcal/d lower than estimated energy requirements with recommended levels of physical activity. This energy gap is likely to contribute to the risk of obesity in this population and future trials are needed to assess implications and potential treatment strategies.
ERIC Educational Resources Information Center
Reed, Keflyn Xavier
A study compared the average reading ability levels of freshmen enrolled at an open-door community college with the readability levels of eight content area textbooks used in courses at the institution. Subjects, 100 students enrolled in reading courses, were randomly selected and administered the Nelson-Denny Reading Test to determine reading…
Inversion Vibrational Energy Levels of AsH3 + Studied by Zero-Kinetic Photoelectron Spectroscopy
NASA Astrophysics Data System (ADS)
Mo, Yuxiang
2016-06-01
The rotational-resolved vibrational spectra of AsH3 + have been measured for the first time with vibrational energies up to 6000 wn above the ground state using zero-kinetic energy photoelectron spectroscopic method. The inversion vibrational energy levels (νb{2}) and the corresponding rotational constants for the νb{2} =0-16 have been determined. The tunneling splittings of the inversion vibration energy levels have been observed for the ground and the first excited vibrational states. The geometric parameters of AsH3 + as a function of inversion vibrational quantum states have been determined, indicating that the geometric structure of the cation changes from near planar structure to a pyramidal structure with more vibrational excitations. In addition to the experimental measurement, a two-dimensional theoretical calculation including the two symmetric vibrational modes was performed to determine the energy levels of the symmetric inversion and As-H stretching vibrations. The calculated vibrational energy levels are in good agreement with the experimental results. The first adiabatic ionization energy (IE) for AsH3 was also accurately determined. The result of this work will be compared with our published result on the PH3+.
Probing Energy Levels of Large Array Quantum Dot Superlattice by Electronic Transport Measurement
NASA Astrophysics Data System (ADS)
Bisri, S. Z.; Degoli, E.; Spallanzani, N.; Krishnan, G.; Kooi, B.; Ghica, C.; Yarema, M.; Protesescu, L.; Heiss, W.; Kovalenko, M.; Pulci, O.; Ossicini, S.; Iwasa, Y.; Loi, M. A.
2015-03-01
Colloidal quantum dot superlattice (CQDS) emerges as new type of hybrid solids allowing easy fabrication of devices that exploits the quantum confinement properties of individual QD. This materials displays peculiar characters, making investigation of their transport properties nontrivial. Besides the bandgap variations, 0D nature of QD lead to the formation of discrete energy subbands. These subbands are crucial for multiple exciton generation (for efficient solar cell), thermoelectric material and multistate transistor. Full understanding of the CQDS energy level structure is vital to use them in complex devices. Here we show a powerful method to determine the CQDS electronic energy levels from their intrinsic charge transport characteristics. Via the use of ambipolar transistors with CQDS as active materials and gated using highly capacitive ionic liquid gating, Fermi energy can be largely tuned. It can access energy levels beyond QD's HOMO & LUMO. Ability to probe not only the bandgap, but also the discrete energy level from large assembly of QD at room temperature suggests the formation of energy minibands in this system.
NASA Technical Reports Server (NTRS)
Ferrario, J.; Byrne, C.; Dupuy, A. E. Jr
1997-01-01
The addition of the "dioxin-like" polychlorinated biphenyl (PCB) congeners to the assessment of risk associated with the 2,3,7,8-chlorine substituted dioxins and furans has dramatically increased the number of laboratories worldwide that are developing analytical procedures for their detection and quantitation. Most of these procedures are based on established sample preparation and analytical techniques employing high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS), which are used for the analyses of dioxin/furans at low parts-per-trillion (ppt) levels. A significant and widespread problem that arises when using these sample preparation procedures for the analysis of coplanar PCBs is the presence of background levels of these congeners. Industrial processes, urban incineration, leaking electrical transformers, hazardous waste accidents, and improper waste disposal practices have released appreciable quantities of PCBs into the environment. This contamination has resulted in the global distribution of these compounds via the atmosphere and their ubiquitous presence in ambient air. The background presence of these compounds in method blanks must be addressed when determining the exact concentrations of these and other congeners in environmental samples. In this study reliable procedures were developed to accurately define these background levels and assess their variability over the course of the study. The background subtraction procedures developed and employed increase the probability that the values reported accurately represent the concentrations found in the samples and were not biased due to this background contamination.
NASA Technical Reports Server (NTRS)
Ferrario, J.; Byrne, C.; Dupuy, A. E. Jr
1997-01-01
The addition of the "dioxin-like" polychlorinated biphenyl (PCB) congeners to the assessment of risk associated with the 2,3,7,8-chlorine substituted dioxins and furans has dramatically increased the number of laboratories worldwide that are developing analytical procedures for their detection and quantitation. Most of these procedures are based on established sample preparation and analytical techniques employing high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS), which are used for the analyses of dioxin/furans at low parts-per-trillion (ppt) levels. A significant and widespread problem that arises when using these sample preparation procedures for the analysis of coplanar PCBs is the presence of background levels of these congeners. Industrial processes, urban incineration, leaking electrical transformers, hazardous waste accidents, and improper waste disposal practices have released appreciable quantities of PCBs into the environment. This contamination has resulted in the global distribution of these compounds via the atmosphere and their ubiquitous presence in ambient air. The background presence of these compounds in method blanks must be addressed when determining the exact concentrations of these and other congeners in environmental samples. In this study reliable procedures were developed to accurately define these background levels and assess their variability over the course of the study. The background subtraction procedures developed and employed increase the probability that the values reported accurately represent the concentrations found in the samples and were not biased due to this background contamination.
Zone Level Occupant-Responsive Building Energy Systems at the GSA
Robinson, Alastair
2014-03-01
The General Services Administration (GSA) partnered with the U.S. Department of Energy (DOE) to develop and implement building energy system retrofits, aiming to reduce energy consumption of at least two building systems by a total of 30 percent or more, as part of DOE’s Commercial Building Partnership (CBP) Program. Lawrence Berkeley National Laboratory (LBNL) provided technical expertise in support of this DOE program, working with the GSA and a team of consultants. This case study reports expected energy savings from appropriate energy efficient design and operations modifications to lighting and heating, ventilating and air conditioning (HVAC) systems at the selected study sites. These retrofits comprised installation of new lighting systems with dimming capability and occupancy-sensor control at the individual light fixture level, and utilized lighting system occupancy sensor signals to continually readjust zone-level ventilation airflow according to the number of people present, down to minimum rates when vacant.
Excitation energy dependence of the level density parameter close to the doubly magic 208Pb
NASA Astrophysics Data System (ADS)
Roy, Pratap; Banerjee, K.; Bhattacharya, C.; Pandey, R.; Sen, A.; Manna, S.; Kundu, S.; Rana, T. K.; Ghosh, T. K.; Mukherjee, G.; Roy, T.; Dhal, A.; Dey, A.; Meena, J. K.; Saha, A. K.; Pandit, Deepak; Mukhopadhyay, S.; Bhattacharya, S.
2016-12-01
Neutron evaporation spectra have been measured from 4He+208Pb and 4He+209Bi reactions by using 4He-ion beams of several bombarding energies. Excitation-energy dependence of the level density parameter has been studied for the two systems in the excitation energy range of ˜18 -50 MeV. For both the reactions an overall reduction of the asymptotic level density parameter with increasing excitation energy (temperature) is observed. The trend of the data was compared with the Thomas-Fermi model predictions and found to be in reasonable agreement. The value of the shell damping parameter has been extracted from the lowest-energy data in the case of Po,211210 and At,212211 nuclei close to the Z =82 and N =126 shell closure, and it was found to be consistent with the recent measurement in the vicinity of doubly magic 208Pb nucleus.
NASA Astrophysics Data System (ADS)
Passante, Gina; Emigh, Paul J.; Shaffer, Peter S.
2015-12-01
[This paper is part of the Focused Collection on Upper Division Physics Courses.] Energy measurements play a fundamental role in the theory of quantum mechanics, yet there is evidence that the underlying concepts are difficult for many students, even after all undergraduate instruction. We present results from an investigation into student ability to determine the possible energies that can be measured for a given wave function and Hamiltonian, to determine the probabilities of each energy measurement and how they depend on time, and to recognize how a measurement of energy affects the state. By analyzing student responses to open-ended questions, we identify five broad, interrelated sets of conceptual and reasoning difficulties related to energy measurements. Data are drawn from sophomore-, junior-, and graduate-level quantum mechanics courses. Particular attention is paid to incorrect ideas that persist across all levels.
Building Industry Research Alliance; Building Science Consortium; Consortium for Advanced Residential Buildings; Florida Solar Energy Center; IBACOS; National Renewable Energy Laboratory
2006-08-01
The Building America program conducts the system research required to reduce risks associated with the design and construction of homes that use an average of 30% to 90% less total energy for all residential energy uses than the Building America Research Benchmark, including research on homes that will use zero net energy on annual basis. To measure the program's progress, annual research milestones have been established for five major climate regions in the United States. The system research activities required to reach each milestone take from 3 to 5 years to complete and include research in individual test houses, studies in pre-production prototypes, and research studies with lead builders that provide early examples that the specified energy savings level can be successfully achieved on a production basis. This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in Cold Climates on a cost-neutral basis.
Developing Energy Literacy in US Middle-Level Students Using the Geospatial Curriculum Approach
NASA Astrophysics Data System (ADS)
Bodzin, Alec M.; Fu, Qiong; Peffer, Tamara E.; Kulo, Violet
2013-06-01
This quantitative study examined the effectiveness of a geospatial curriculum approach to promote energy literacy in an urban school district and examined factors that may account for energy content knowledge achievement. An energy literacy measure was administered to 1,044 eighth-grade students (ages 13-15) in an urban school district in Pennsylvania, USA. One group of students received instruction with a geospatial curriculum approach (geospatial technologies (GT)) and another group of students received 'business as usual' (BAU) curriculum instruction. For the GT students, findings revealed statistically significant gains from pretest to posttest (p < 0.001) on knowledge of energy resource acquisition, energy generation, storage and transport, and energy consumption and conservation. The GT students had year-end energy content knowledge scores significantly higher than those who learned with the BAU curriculum (p < 0.001; effect size being large). A multiple regression found that prior energy content knowledge was the only significant predictor to the year-end energy content knowledge achievement for the GT students (p < 0.001). The findings support that the implementation of a geospatial curriculum approach that employs learning activities that focus on the spatial nature of energy resources can improve the energy literacy of urban middle-level education students.
Delahaye, Thibault; Nikitin, Andrei; Rey, Michaël; Szalay, Péter G; Tyuterev, Vladimir G
2014-09-14
In this paper we report a new ground state potential energy surface for ethylene (ethene) C2H4 obtained from extended ab initio calculations. The coupled-cluster approach with the perturbative inclusion of the connected triple excitations CCSD(T) and correlation consistent polarized valence basis set cc-pVQZ was employed for computations of electronic ground state energies. The fit of the surface included 82,542 nuclear configurations using sixth order expansion in curvilinear symmetry-adapted coordinates involving 2236 parameters. A good convergence for variationally computed vibrational levels of the C2H4 molecule was obtained with a RMS(Obs.-Calc.) deviation of 2.7 cm(-1) for fundamental bands centers and 5.9 cm(-1) for vibrational bands up to 7800 cm(-1). Large scale vibrational and rotational calculations for (12)C2H4, (13)C2H4, and (12)C2D4 isotopologues were performed using this new surface. Energy levels for J = 20 up to 6000 cm(-1) are in a good agreement with observations. This represents a considerable improvement with respect to available global predictions of vibrational levels of (13)C2H4 and (12)C2D4 and rovibrational levels of (12)C2H4.
Wave energy level and geographic setting correlate with Florida beach water quality.
Feng, Zhixuan; Reniers, Ad; Haus, Brian K; Solo-Gabriele, Helena M; Kelly, Elizabeth A
2016-03-15
Many recreational beaches suffer from elevated levels of microorganisms, resulting in beach advisories and closures due to lack of compliance with Environmental Protection Agency guidelines. We conducted the first statewide beach water quality assessment by analyzing decadal records of fecal indicator bacteria (enterococci and fecal coliform) levels at 262 Florida beaches. The objectives were to depict synoptic patterns of beach water quality exceedance along the entire Florida shoreline and to evaluate their relationships with wave condition and geographic location. Percent exceedances based on enterococci and fecal coliform were negatively correlated with both long-term mean wave energy and beach slope. Also, Gulf of Mexico beaches exceeded the thresholds significantly more than Atlantic Ocean ones, perhaps partially due to the lower wave energy. A possible linkage between wave energy level and water quality is beach sand, a pervasive nonpoint source that tends to harbor more bacteria in the low-wave-energy environment. Copyright © 2016 Elsevier Ltd. All rights reserved.
Hawkey, Elizabeth; Nigg, Joel T.
2015-01-01
Interest in the value of Omega—3 (n—3) fatty acid supplementation for treatment of ADHD remains high. No prior meta-analysis has examined whether ADHD is associated with alterations in blood lipid levels and meta-analyses of supplementation have reached conflicting conclusions. Methods We report two new meta-analyses. Study 1 examined blood levels of Omega—3 fatty acids in relation to ADHD. Study 2 examined a larger sample of randomized intervention trials than previously reported. Results Study 1 included 9 studies (n = 586) and found lower overall blood levels of n—3 in individuals with ADHD versus controls (g = 0.42, 95% CI = 0.26–0.59; p < .001). Study 2 included 16 studies (n = 1408) and found that n—3 supplementation improved ADHD composite symptoms; using the best available rating and reporter (g = 0.26, 95% CI = 0.15–0.37; p < .001). Supplementation showed reliable effects on hyperactivity by parent and teacher report, but reliable effects for inattention only by parent report. Conclusions Omega—3 levels are reduced in children with ADHD. Dietary supplementation appears to create modest improvements in symptoms. There is sufficient evidence to consider Omega—3 fatty acids as a possible supplement to established therapies. However it remains unclear whether such intervention should be confined to children with below normal blood levels. PMID:25181335
NASA Astrophysics Data System (ADS)
Ehara, Masahiro; Oyagi, Fumito; Abe, Yoko; Fukuda, Ryoichi; Nakatsuji, Hiroshi
2011-07-01
In this series of studies, we systematically apply the analytical energy gradients of the direct symmetry-adapted cluster-configuration interaction singles and doubles nonvariational method to calculate the equilibrium geometries and vibrational frequencies of excited and ionized states of molecules. The harmonic vibrational frequencies were calculated using the second derivatives numerically computed from the analytical first derivatives and the anharmonicity was evaluated from the three-dimensional potential energy surfaces around the local minima. In this paper, the method is applied to the low-lying valence singlet and triplet excited states of HAX-type molecules, HCF, HCCl, HSiF, HSiCl, HNO, HPO, and their deuterium isotopomers. The vibrational level emission spectra of HSiF and DSiF and absorption spectra of HSiCl and DSiCl were also simulated within the Franck-Condon approximation and agree well with the experimental spectra. The results show that the present method is useful and reliable for calculating these quantities and spectra. The change in geometry in the excited states was qualitatively interpreted in the light of the electrostatic force theory. The effect of perturbation selection with the localized molecular orbitals on the geometrical parameters and harmonic vibrational frequencies is also discussed.
ERIC Educational Resources Information Center
Trumper, Ricardo; Gorsky, Paul
1993-01-01
This study found no significant relations between junior high school students' (n=50) prior alternative frameworks on energy and their cognitive levels of operation. Significant differences in learning outcomes were achieved by students (n=29) who had higher cognitive level scores. The extent to which students succeeded in learning the energy…
Energy levels, oscillator strengths, and transition probabilities for sulfur-like scandium, Sc VI
NASA Astrophysics Data System (ADS)
El-Maaref, A. A.; Abou Halaka, M. M.; Saddeek, Yasser B.
2017-09-01
Energy levels, Oscillator strengths, and transition probabilities for sulfur-like scandium are calculated using CIV3 code. The calculations have been executed in an intermediate coupling scheme using Breit-Pauli Hamiltonian. The present calculations have been compared with the experimental data and other theoretical calculations. LANL code has been used to confirm the accuracy of the present calculations, where the calculations using CIV3 code agree well with the corresponding values by LANL code. The calculated energy levels and oscillator strengths are in reasonable agreement with the published experimental data and theoretical values. We have calculated lifetimes of some excited levels, as well.