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.
NASA Astrophysics Data System (ADS)
Tamandani, Shahryar; Darvish, Ghafar; Faez, Rahim
2016-01-01
In this paper by solving Dirac equation, we present an analytical solution to calculate energy levels and wave functions of mono- and bilayer graphene quantum dots. By supposing circular quantum dots, we solve Dirac equation and obtain energy levels and band gap with relations in a new closed and practical form. The energy levels are correlated with a radial quantum number and radius of quantum dots. In addition to monolayer quantum dots, AA- and AB-stacked bilayer quantum dots are investigated and their energy levels and band gap are calculated as well. Also, we analyze the influence of the quantum dots size on their energy spectrum. It can be observed that the band gap decreases as quantum dots' radius increases. On the other hand, increase in the band gap is more in AB-stacked bilayer quantum dots. Using the obtained relations, the band gap is obtained in each state. Comparing the energy spectra obtained from the tight-binding approximation with those of our obtained relations shows that the behavior of the energies as function of the dot size is qualitatively similar, but in some cases, quantitative differences can be seen. As quantum dots radius increases, the analytical results approach to the tight-binding method results.
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.
Marquardt, Roberto; Sagui, Kenneth; Zheng, Jingjing; Thiel, Walter; Luckhaus, David; Yurchenko, Sergey; Mariotti, Fabio; Quack, Martin
2013-08-15
The analytical, full-dimensional, and global representation of the potential energy surface of NH(3) in the lowest adiabatic electronic state developed previously (Marquardt, R.; et al. J. Phys. Chem. B 2005, 109, 8439–8451) is improved by adjustment of parameters to an enlarged set of electronic energies from ab initio calculations using the coupled cluster method with single and double substitutions and a perturbative treatment of connected triple excitations (CCSD(T)) and the method of multireference configuration interaction (MRCI). CCSD(T) data were obtained from an extrapolation of aug-cc-pVXZ results to the basis set limit (CBS), as described in a previous work (Yurchenko, S.N.; et al. J. Chem. Phys 2005, 123, 134308); they cover the region around the NH3 equilibrium structures up to 20,000 hc cm(–1). MRCI energies were computed using the aug-cc-pVQZ basis to describe both low lying singlet dissociation channels. Adjustment was performed simultaneously to energies obtained from the different ab initio methods using a merging strategy that includes 10,000 geometries at the CCSD(T) level and 500 geometries at the MRCI level. Characteristic features of this improved representation are NH3 equilibrium geometry r(eq)(NH(3)) ≈ 101.28 pm, α(eq)(NH(3)) ≈ 107.03°, the inversion barrier at r(inv)(NH(3)) ≈ 99.88 pm and 1774 hc cm(–1) above the NH(3) minimum, and dissociation channel energies 41,051 hc cm(–1) (for NH(3) → ((2)B(2))NH(2) + ((2)S(1/2))H) and 38,450 hc cm(–1) (for NH(3) → ((3)Σ(–))NH +((1)Σ(g)(+))H(2)); the average agreement between calculated and experimental vibrational line positions is 11 cm(–1) for (14)N(1)H(3) in the spectral region up to 5000 cm(–1). A survey of our current knowledge on the vibrational spectroscopy of ammonia and its isotopomers is also given. PMID:23688044
NASA Astrophysics Data System (ADS)
Fouillant, C.; Alibert, C.
1994-06-01
Many articles on the determination of the energy levels of a symmetric rectangular quantum well (SRQW) have been published in this Journal over the past 20 years. Standard textbooks of quantum mechanics as well as research papers offer graphical solutions. Exercises on quantum well (QW) remain rather difficult for students, because transcendental equations must be solved with boundaries at which the solution will be discontinuous. Numerical solutions generally determine the energy (En), assuming that the thickness is known, for each level number n. In this note, we show that the width L of an SRQW can be expressed directly as a function of the energy En for n=0,1,2,3,... .
Analytic and Informational Support for State-Level Academic Planning.
ERIC Educational Resources Information Center
Caruthers, J. Kent; Orwig, Melvin D.
Any state-level postsecondary education agency could perform its job more effectively through discriminate use of the available technology of informational and analytic planning approaches. The paper attempts to increase an awareness of how data, analytic techniques, and their product information should be used to assist state-level academic…
Analytic solution and pulse area theorem for three-level atoms
NASA Astrophysics Data System (ADS)
Shchedrin, Gavriil; O'Brien, Chris; Rostovtsev, Yuri; Scully, Marlan O.
2015-12-01
We report an analytic solution for a three-level atom driven by arbitrary time-dependent electromagnetic pulses. In particular, we consider far-detuned driving pulses and show an excellent match between our analytic result and the numerical simulations. We use our solution to derive a pulse area theorem for three-level V and Λ systems without making the rotating wave approximation. Formulated as an energy conservation law, this pulse area theorem can be used to understand pulse propagation through three-level media.
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.
Analytically solvable driven time-dependent two-level quantum systems
NASA Astrophysics Data System (ADS)
Barnes, Edwin; Das Sarma, Sankar
2013-03-01
Analytical solutions to the time-dependent Schrodinger equation describing a driven two-level system are invaluable to many areas of physics, but they are also extremely rare. Here, we present a simple algorithm based on a type of partial reverse-engineering that generates an unlimited number of exact analytical solutions for a general time-dependent Hamiltonian. We demonstrate this method by presenting several new exact solutions that are particularly relevant to qubit control in quantum computing applications. We further show that our formalism easily generates analytical control protocols for performing sweeps across energy level anti-crossings that execute perfect Landau-Zener interferometry and rapid adiabatic passage near the quantum speed limit. Work supported by LPS-CMTC, CNAM and IARPA
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.
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.
Analytical gradients for excitation energies from frozen-density embedding.
Kovyrshin, Arseny; Neugebauer, Johannes
2016-08-21
The formulation of analytical excitation-energy gradients from time-dependent density functional theory within the frozen-density embedding framework is presented. In addition to a comprehensive mathematical derivation, we discuss details of the numerical implementation in the Slater-function based Amsterdam Density Functional (ADF) program. Particular emphasis is put on the consistency in the use of approximations for the evaluation of second- and third-order non-additive kinetic-energy and exchange-correlation functional derivatives appearing in the final expression for the excitation-energy gradient. We test the implementation for different chemical systems in which molecular excited-state potential-energy curves are affected by another subsystem. It is demonstrated that the analytical implementation for the evaluation of excitation-energy gradients yields results in close agreement with data from numerical differentiation. In addition, we show that our analytical results are numerically more stable and thus preferable over the numerical ones. PMID:26996970
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... accordance with § 530.22, the following analytical methods have been accepted by FDA:...
The energy of the analytic lump solution in SFT
NASA Astrophysics Data System (ADS)
Bonora, L.; Giaccari, S.; Tolla, D. D.
2011-08-01
In a previous paper a method was proposed to find exact analytic solutions of open string field theory describing lower dimensional lumps, by incorporating in string field theory an exact renormalization group flow generated by a relevant operator in a worldsheet CFT. In this paper we compute the energy of one such solution, which is expected to represent a D24 brane. We show, both numerically and analytically, that its value corresponds to the theoretically expected one.
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.
Analytical theory of strongly correlated Wigner crystals in the lowest Landau level
NASA Astrophysics Data System (ADS)
Rhim, Jun-Won; Jain, Jainendra K.; Park, Kwon
2015-09-01
In this work, we present an analytical theory of strongly correlated Wigner crystals (WCs) in the lowest Landau level (LLL) by constructing an approximate, but accurate effective two-body interaction for composite fermions (CFs) participating in the WCs. This requires integrating out the degrees of freedom of all surrounding CFs, which we accomplish analytically by approximating their wave functions by delta functions. This method produces energies of various strongly correlated WCs that are in excellent agreement with those obtained from the Monte Carlo simulation of the full CF crystal wave functions. We compute the compressibility of the strongly correlated WCs in the LLL and predict discontinuous changes at the phase boundaries separating different crystal phases.
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2010 CFR
2010-04-01
... analytical method; or (3) Establish a safe level based on other appropriate scientific, technical, or regulatory criteria. (b) FDA may require the development of an acceptable analytical method for the... such an acceptable analytical method, the agency will publish notice of that requirement in the...
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2011 CFR
2011-04-01
... analytical method; or (3) Establish a safe level based on other appropriate scientific, technical, or regulatory criteria. (b) FDA may require the development of an acceptable analytical method for the... such an acceptable analytical method, the agency will publish notice of that requirement in the...
Electron energy distribution in a dusty plasma: analytical approach.
Denysenko, I B; Kersten, H; Azarenkov, N A
2015-09-01
Analytical expressions describing the electron energy distribution function (EEDF) in a dusty plasma are obtained from the homogeneous Boltzmann equation for electrons. The expressions are derived neglecting electron-electron collisions, as well as transformation of high-energy electrons into low-energy electrons at inelastic electron-atom collisions. At large electron energies, the quasiclassical approach for calculation of the EEDF is applied. For the moderate energies, we account for inelastic electron-atom collisions in the dust-free case and both inelastic electron-atom and electron-dust collisions in the dusty plasma case. Using these analytical expressions and the balance equation for dust charging, the electron energy distribution function, the effective electron temperature, the dust charge, and the dust surface potential are obtained for different dust radii and densities, as well as for different electron densities and radio-frequency (rf) field amplitudes and frequencies. The dusty plasma parameters are compared with those calculated numerically by a finite-difference method taking into account electron-electron collisions and the transformation of high-energy electrons at inelastic electron-neutral collisions. It is shown that the analytical expressions can be used for calculation of the EEDF and dusty plasma parameters at typical experimental conditions, in particular, in the positive column of a direct-current glow discharge and in the case of an rf plasma maintained by an electric field with frequency f=13.56MHz. PMID:26465570
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
Unitary Operations: The Relationship between Level of Moral Development and Analytic Style.
ERIC Educational Resources Information Center
Woog, Pierre
Despite the relevance of moral development to professional education, little research has been done to examine the application of moral development theory. To relate Analytic Interactive Style to post-formal operational thinking or "unitary operations thinking," to test the relationship between level of moral development and Analytic Interactive…
NASA Astrophysics Data System (ADS)
Yun, Dong-Jin; Chung, JaeGwan; Kim, Seong Heon; Kim, Yongsu; Park, SungHoon; Seol, Minsu; Heo, Sung
2015-11-01
Poly(3, 4-ethylenedioxythiophene) (PEDOT) polymerized with poly(4-styrenesulfonate) (PSS) is one of the most widely used conducting organic electrodes owing to its outstanding optical/electrical properties and high work function. Because its work function depends significantly on the molecular arrangements between PEDOT and PSS molecules on the surface, the contact position of PEDOT:PSS films on organic semiconductors (OSCs) must also be an essential consideration. However, existing analysis methods based on in situ deposition/analysis are limited in their ability to accurately investigate the electronic structures of the buried interface regions under the solution-processed electrode or OSC layer in organic devices. Therefore, to overcome such limitations, we propose a top-down method based on photoemission spectroscopy analysis combined with Ar gas cluster ion beam (GCIB) sputtering. Through this method, both energy-level alignments and molecular distributions at various OSC/electrode interfaces can be successfully characterized without reference to any deposition process.
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.
CoNNECT: Data Analytics for Energy Efficient Communities
Omitaomu, Olufemi A; Bhaduri, Budhendra L; Kodysh, Jeffrey B
2012-01-01
Energy efficiency is the lowest cost option being promoted for achieving a sustainable energy policy. Thus, there have been some innovations to reduce residential and commercial energy usage. There have also been calls to the utility companies to give customers access to timely, useful, and actionable information about their energy use, in order to unleash additional innovations in homes and businesses. Hence, some web-based tools have been developed for the public to access and compare energy usage data. In order to advance on these efforts, we propose a data analytics framework called Citizen Engagement for Energy Efficient Communities (CoNNECT). On the one hand, CoNNECT will help households to understand (i) the patterns in their energy consumption over time and how those patterns correlate with weather data, (ii) how their monthly consumption compares to other households living in houses of similar size and age within the same geographic areas, and (iii) what other customers are doing to reduce their energy consumption. We hope that the availability of such data and analysis to the public will facilitate energy efficiency efforts in residential buildings. These capabilities formed the public portal of the CoNNECT framework. On the other hand, CoNNECT will help the utility companies to better understand their customers by making available to the utilities additional datasets that they naturally do not have access to, which could help them develop focused services for their customers. These additional capabilities are parts of the utility portal of the CoNNECT framework. In this paper, we describe the CoNNECT framework, the sources of the data used in its development, the functionalities of both the public and utility portals, and the application of empirical mode decomposition for decomposing usage signals into mode functions with the hope that such mode functions could help in clustering customers into unique groups and in developing guidelines for energy
Model for analytical calculation of nuclear photoabsorption at intermediate energies
NASA Astrophysics Data System (ADS)
Hütt, M.-Th.; Milstein, A. I.; Schumacher, M.
1997-02-01
The universal curve {σ}/{A} of nuclear photoabsorption is investigated within a Fermi gas model of nuclear matter. An energy range from pion threshold up to 400 MeV is considered. The interactions between nucleon, pion, Δ-isobar and photon are considered in the non-relativistic approximation with corrections of the order {1}/{M} taken into account with respect to proton mass. Analytical expressions are obtained, in which the influence of nuclear correlations and two-nucleon contributions is studied explicitly. The contributions of real and virtual pions are found to be sufficient to obtain agreement with experimental data in this energy range. An extension of the model calculation to nucleon knock-out reactions is discussed.
Analytic energy gradients for constrained DFT-configuration interaction
NASA Astrophysics Data System (ADS)
Kaduk, Benjamin; Tsuchimochi, Takashi; Van Voorhis, Troy
2014-05-01
The constrained density functional theory-configuration interaction (CDFT-CI) method has previously been used to calculate ground-state energies and barrier heights, and to describe electronic excited states, in particular conical intersections. However, the method has been limited to evaluating the electronic energy at just a single nuclear configuration, with the gradient of the energy being available only via finite difference. In this paper, we present analytic gradients of the CDFT-CI energy with respect to nuclear coordinates, which gives the potential for accurate geometry optimization and molecular dynamics on both the ground and excited electronic states, a realm which is currently quite challenging for electronic structure theory. We report the performance of CDFT-CI geometry optimization for representative reaction transition states as well as molecules in an excited state. The overall accuracy of CDFT-CI for computing barrier heights is essentially unchanged whether the energies are evaluated at geometries obtained from quadratic configuration-interaction singles and doubles (QCISD) or CDFT-CI, indicating that CDFT-CI produces very good reaction transition states. These results open up tantalizing possibilities for future work on excited states.
The finite time multi-level SU(2) Landau-Zener problems: exact analytical results
NASA Astrophysics Data System (ADS)
Mkam Tchouobiap, S. E.; Kenmoe, M. B.; Fai, L. C.
2015-10-01
The multi-level SU(2) Landau-Zener problem is analytically solved at finite time within the framework of the Bloch tensor formalism and with the help of the disentanglement Wei-Norman ordering technique. A generalized and exact analytical solution is achieved that accounts not only for all projections of an arbitrary spin S along the Zeeman field direction but also for non-adiabatic and adiabatic evolutions.
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…
Analytical results for cell constriction dominated by bending energy.
Almendro-Vedia, Victor G; Monroy, Francisco; Cao, Francisco J
2015-01-01
Analytical expressions are obtained for the main magnitudes of a symmetrically constricted vesicle. These equations provide an easy and compact way to predict minimal requirements for successful constriction and its main magnitudes. Thus, they can be useful for the design of synthetic divisomes and give good predictions for magnitudes including constriction energy, length of the constriction zone, volume and area of the vesicle, and the stability coefficient for symmetric constriction. The analytical expressions are derived combining a perturbative expansion in the Lagrangian for small deformations with a cosine ansatz in the constriction region. Already the simple fourth-order (or sixth-order) approximation provides a good approximation to the values of the main physical magnitudes during constriction, as we show through comparison with numerical results. Results are for vesicles with negligible effects from spontaneous curvature, surface tension, and pressure differences. This is the case when membrane components generating spontaneous curvature are scarce, membrane trafficking is present with low energetic cost, and the external medium is isotonic. PMID:25679648
Analytic results for the Casimir free energy between ferromagnetic metals
NASA Astrophysics Data System (ADS)
Klimchitskaya, G. L.; Korikov, C. C.
2015-03-01
We derive perturbation analytic expressions for the Casimir free energy and entropy between two dissimilar ferromagnetic plates which are applicable at arbitrarily low temperature. The dielectric properties of metals are described using either the nondissipative plasma model or the Drude model taking into account the dissipation of free charge carriers. Both cases of constant and frequency-dependent magnetic permeability are considered. It is shown that for ferromagnetic metals described by the plasma model the Casimir entropy goes to zero when the temperature vanishes, i.e., the Nernst heat theorem is satisfied. For ferromagnetic metals with perfect crystal lattices described by the Drude model the Casimir entropy goes to a nonzero constant depending on the parameters of a system with vanishing temperature, i.e., the Nernst heat theorem is violated. This constant can be positive which is quite different from the earlier investigated case of two nonmagnetic metals.
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.
Semi-analytic galaxy formation in coupled dark energy cosmologies
NASA Astrophysics Data System (ADS)
Fontanot, Fabio; Baldi, Marco; Springel, Volker; Bianchi, Davide
2015-09-01
Among the possible alternatives to the standard cosmological model (ΛCDM), coupled dark energy models postulate that dark energy (DE), seen as a dynamical scalar field, may interact with dark matter (DM), giving rise to a `fifth-force', felt by DM particles only. In this paper, we study the impact of these cosmologies on the statistical properties of galaxy populations by combining high-resolution numerical simulations with semi-analytic models (SAMs) of galaxy formation and evolution. New features have been implemented in the reference SAM in order to have it run self-consistently and calibrated on these cosmological simulations. They include an appropriate modification of the mass-temperature relation and of the baryon fraction in DM haloes, due to the different virial scalings and to the gravitational bias, respectively. Our results show that the predictions of our coupled-DE SAM do not differ significantly from theoretical predictions obtained with standard SAMs applied to a reference Λ cold dark matter (ΛCDM) simulation, implying that the statistical properties of galaxies provide only a weak probe for these alternative cosmological models. On the other hand, we show that both galaxy bias and the galaxy pairwise velocity distribution are sensitive to coupled DE models: this implies that these probes might be successfully applied to disentangle among quintessence, f(R)-gravity and coupled DE models.
Analytical solutions for a two-level system driven by a class of chirped pulses
Jha, Pankaj K.; Rostovtsev, Yuri V.
2010-07-15
We present analytical solutions for the problem of a two-level atom driven by a class of chirped pulses. The solutions are given in terms of Heun functions. By use of the appropriate chirping parameters, an enhancement of four orders of magnitude in the population transfer is obtained.
Analytical characterization of high-level mixed wastes using multiple sample preparation treatments
King, A.G.; Baldwin, D.L.; Urie, M.W.; McKinley, S.G.
1994-09-01
The Analytical Chemistry Laboratory at the Pacific Northwest Laboratory in Richland, Washington, is actively involved in performing analytical characterization of high-level mixed waste from Hanford`s single shell and double shell tank characterization programs. A full suite of analyses is typically performed on homogenized tank core samples. These analytical techniques include inductively-coupled plasma-atomic emission spectroscopy, total organic carbon methods and radiochemistry methods, as well as many others, all requiring some type of remote sample-preparation treatment to solubilize the tank sludge material for analysis. Most of these analytical methods typically use a single sample-preparation treatment, inherently providing elemental information only. To better understand and interpret tank chemistry and assist in identifying chemical compounds, selected analytical methods are performed using multiple sample-preparation treatments. The sample preparation treatments used at Pacific Northwest Laboratory for this work with high-level mixed waste include caustic fusion, acid digestion, and water leach. The type of information available by comparing results from different sample-prep treatments includes evidence for the presence of refractory compounds, acid-soluble compounds, or water-soluble compounds. Problems unique to the analysis of Hanford tank wastes are discussed. Selected results from the Hanford single shell ferrocyanide tank, 241-C-109, are presented, and the resulting conclusions are discussed.
NASA Astrophysics Data System (ADS)
Khoa, Dinh Xuan; Van Trong, Pham; Van Doai, Le; Bang, Nguyen Huy
2016-03-01
We develop an analytical approach on electromagnetically induced transparency (EIT) in a Doppler broadened medium consisting of five-level cascade systems excited by a strong coupling and weak probe laser fields. In a weak field limit of the probe light, EIT spectrum is interpreted as functions of controllable parameters of the coupling light and temperature of the medium. The theoretical interpretation of EIT spectrum is applied to the case of 85Rb atoms and compared with available experimental observation. Such an analytical interpretation provides quantitative parameters to control properties of the Doppler broadened EIT medium, and it is useful to find related applications.
Analytically solvable two-level quantum systems and Landau-Zener interferometry
NASA Astrophysics Data System (ADS)
Barnes, Edwin
2013-07-01
A simple algorithm is presented based on a type of partial reverse engineering that generates an unlimited number of exact analytical solutions to the Schrödinger equation for a general time-dependent two-level Hamiltonian. I demonstrate this method by deriving exact solutions corresponding to fast control pulses that contain arbitrarily many tunable parameters. It is shown that the formalism is naturally suited to generating analytical control protocols that perform precise nonadiabatic rapid passage and Landau-Zener interferometry near the quantum speed limit. A general, exact formula for Landau-Zener interference patterns is derived.
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.
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).
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.
A Global Analytical Representation of the Potential Energy Surface of the FHF(-) Anion.
Cornaton, Yann; Marquardt, Roberto
2016-08-01
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. PMID:27400137
NASA Astrophysics Data System (ADS)
Cai, H.; Savenije, H. H. G.; Jiang, C.
2014-06-01
As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we investigate the influence of river discharge on tidal wave propagation in the Yangtze estuary with specific attention to residual water level slope. This is done by using a one-dimensional analytical model for tidal hydrodynamics accounting for the residual water level. We demonstrate the importance of the residual slope on tidal dynamics and use it to improve the prediction of the tidal propagation in estuaries (i.e., tidal damping, velocity amplitude, wave celerity and phase lag), especially when the influence of river discharge is significant. Finally, we develop a new inverse analytical approach for estimating fresh water discharge on the basis of tidal water level observations along the estuary, which can be used as a tool to obtain information on the river discharge that is otherwise difficult to measure in the tidal region.
NASA Astrophysics Data System (ADS)
Cai, H.; Savenije, H. H. G.; Jiang, C.
2014-10-01
As the tidal wave propagates into an estuary, the tidally averaged water level tends to rise in landward direction due to the density difference between saline and fresh water and the asymmetry of the friction. The effect of friction on the residual slope is even more remarkable when accounting for fresh water discharge. In this study, we investigate the influence of river discharge on tidal wave propagation in the Yangtze estuary with specific attention to residual water level slope. This is done by using a one-dimensional analytical model for tidal hydrodynamics accounting for the residual water level. We demonstrate the importance of the residual slope on tidal dynamics and use it to improve the prediction of the tidal propagation in estuaries (i.e. tidal damping, velocity amplitude, wave celerity and phase lag), especially when the influence of river discharge is significant. Finally, we develop a new inverse analytical approach for estimating fresh water discharge on the basis of tidal water level observations along the estuary, which can be used as a tool to obtain information on the river discharge that is otherwise difficult to measure in the tidal region.
NASA Astrophysics Data System (ADS)
Zaluzec, Nester J.
Developments in instrumentation for both X ray Dispersive and Electron Energy Loss Spectroscopy (XEDS/EELS) over the last ten years have given the experimentalist a greatly enhanced set of analytical tools for characterization. Microanalysts have waited for nearly two decades now in the hope of getting a true analytical microscope and the development of 300 to 400 kV instruments should have allowed us to attain this goal. Unfortunately, this has not generally been the case. While there have been some major improvements in the techniques, there has also been some devolution in the modern AEM (Analytical Electron Microscope). In XEDS, the majority of today's instruments are still plagued by the hole count effect, which was first described in detail over fifteen years ago. The magnitude of this problem can still reach the 20 percent level for medium atomic number species in a conventional off-the-shelf intermediate voltage AEM. This is an absurd situation and the manufacturers should be severely criticized. Part of the blame, however, also rests on the AEM community for not having come up with a universally agreed upon standard test procedure. Fortunately, such a test procedure is in the early stages of refinement. The proposed test specimen consists of an evaporated Cr film approx. 500 to 1000A thick supported upon a 3mm diameter Molybdenum 200 micron aperture.
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.
A simple volcano potential with an analytic, zero-energy, ground state
NASA Astrophysics Data System (ADS)
Nieto, M. M.
2000-08-01
We describe a simple volcano potential, which is supersymmetric and has an analytic, zero-energy, ground state. (The KK modes are also analytic.) It is an interior harmonic oscillator potential properly matched to an exterior angular momentum-like tail. Special cases are given to elucidate the physics, which may be intuitively useful in studies of higher-dimensional gravity.
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.
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.
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.
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.
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 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.
Optimum filter selection for Dual Energy X-ray Applications through Analytical Modeling
NASA Astrophysics Data System (ADS)
Koukou, V.; Martini, N.; Michail, C.; Sotiropoulou, P.; Kalyvas, N.; Kandarakis, I.; Nikiforidis, G.; Fountos, G.
2015-09-01
In this simulation study, an analytical model was used in order to determine the optimal acquisition parameters for a dual energy breast imaging system. The modeled detector system, consisted of a 33.91mg/cm2 Gd2O2S:Tb scintillator screen, placed in direct contact with a high resolution CMOS sensor. Tungsten anode X-ray spectra, filtered with various filter materials and filter thicknesses were examined for both the low- and high-energy beams, resulting in 3375 combinations. The selection of these filters was based on their K absorption edge (K-edge filtering). The calcification signal-to-noise ratio (SNRtc) and the mean glandular dose (MGD) were calculated. The total mean glandular dose was constrained to be within acceptable levels. Optimization was based on the maximization of the SNRtc/MGD ratio. The results showed that the optimum spectral combination was 40kVp with added beam filtration of 100 μm Ag and 70kVp Cu filtered spectrum of 1000 μm for the low- and high-energy, respectively. The minimum detectable calcification size was 150 μm. Simulations demonstrate that this dual energy X-ray technique could enhance breast calcification detection.
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.
NASA Technical Reports Server (NTRS)
Naumann, Robert J.; Baugher, Charles
1992-01-01
Approximate analytical solutions are developed that are mathematically tractable but provide the elements of CFD models for estimating convective flows subjected to low-level accelerations. The estimates are applicable to dilute systems that have horizontal temperature gradients in the vertical Bridgman configuration. The Navier-Stokes momentum equation is solved in 1D and subsequently in 2D by the first-order perturbation method. The analysis used is the case of plane-front solidification of a dilute system in the vertical thermally stable configuration. The model is found to predict the degree of radial segregation within a factor of two for a range of material and processing parameters. The method provides detailed information on the effects of processing on solute distribution in the grown crystal which are of interest in the orbital experiments emphasizing the control of radial segregation.
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…
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. PMID:24433204
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…
Omitaomu, Olufemi A; 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.
Analytical energy and bandwidth model for compact silicon photonic microdisk resonators.
Zortman, William A.; Trotter, Douglas Chandler; Watts, Michael R.
2009-04-01
Microdisk resonators for use as low energy modulators in telecom and datacom applications have been fabricated using vertical PN junctions which operate in reverse bias. These devices have demonstrated the lowest energy/bit thus far. In this paper we show that the reverse biased PN junction diodes follow the analytical depletion approximation based on numerical simulation.
Analytical framework for evaluating energy and capacity shortages. Final report
Mosbaek, E.J.
1980-04-01
A methodology for estimating shortage cost is presented, and two examples of shortage costs are given, namely: the 1976-1977 winter shortfall in natural-gas supply, and a 1978 spot shortage in electric power. The methodology shows how to develop a comprehensive estimate of willingness-to-pay to avoid shortages - a total comprised of the willingness-to-pay producers, employees, consumers, and the general public. The 1976-1977 natural gas experience indicates that total costs per million Btu's of shortage (i.e., the cost for every Mcf of curtailment to non-residential users who are not normally curtailed) are $54 and $5 for capacity and energy shortages, respectively. The dielectric power shortage indicates that total costs per million Btu's of shortage are $670 (i.e., a cost of $2.30 for every kWh of shortage to non-residential users).
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. PMID:25661111
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 for F-16 (Fluorine-16)
NASA Astrophysics Data System (ADS)
Sukhoruchkin, S. I.; Soroko, Z. N.
This document is part of Subvolume C `Tables of Excitations of Proton- and Neutron-rich Unstable Nuclei' of Volume 19 `Nuclear States from Charged Particle Reactions' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides energy levels for atomic nuclei of the isotope F-16 (fluorine, atomic number Z = 9, mass number A = 16).
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.
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.
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.
NASA Astrophysics Data System (ADS)
Sklarz, Shlomo E.; Tannor, David J.; Khaneja, Navin
2004-05-01
We study the problem of optimal control of dissipative quantum dynamics. Although under most circumstances dissipation leads to an increase in entropy (or a decrease in purity) of the system, there is an important class of problems for which dissipation with external control can decrease the entropy (or increase the purity) of the system. An important example is laser cooling. In such systems, there is an interplay of the Hamiltonian part of the dynamics, which is controllable, and the dissipative part of the dynamics, which is uncontrollable. The strategy is to control the Hamiltonian portion of the evolution in such a way that the dissipation causes the purity of the system to increase rather than decrease. The goal of this paper is to find the strategy that leads to maximal purity at the final time. Under the assumption that Hamiltonian control is complete and arbitrarily fast, we provide a general framework by which to calculate optimal cooling strategies. These assumptions lead to a great simplification, in which the control problem can be reformulated in terms of the spectrum of eigenvalues of ρ , rather than ρ itself. By combining this formulation with the Hamilton-Jacobi-Bellman theorem we are able to obtain an equation for the globally optimal cooling strategy in terms of the spectrum of the density matrix. For the three-level Λ system, we provide a complete analytic solution for the optimal cooling strategy. For this system it is found that the optimal strategy does not exploit system coherences and is a “greedy” strategy, in which the purity is increased maximally at each instant.
Sklarz, Shlomo E.; Tannor, David J.; Khaneja, Navin
2004-05-01
We study the problem of optimal control of dissipative quantum dynamics. Although under most circumstances dissipation leads to an increase in entropy (or a decrease in purity) of the system, there is an important class of problems for which dissipation with external control can decrease the entropy (or increase the purity) of the system. An important example is laser cooling. In such systems, there is an interplay of the Hamiltonian part of the dynamics, which is controllable, and the dissipative part of the dynamics, which is uncontrollable. The strategy is to control the Hamiltonian portion of the evolution in such a way that the dissipation causes the purity of the system to increase rather than decrease. The goal of this paper is to find the strategy that leads to maximal purity at the final time. Under the assumption that Hamiltonian control is complete and arbitrarily fast, we provide a general framework by which to calculate optimal cooling strategies. These assumptions lead to a great simplification, in which the control problem can be reformulated in terms of the spectrum of eigenvalues of {rho}, rather than {rho} itself. By combining this formulation with the Hamilton-Jacobi-Bellman theorem we are able to obtain an equation for the globally optimal cooling strategy in terms of the spectrum of the density matrix. For the three-level {lambda} system, we provide a complete analytic solution for the optimal cooling strategy. For this system it is found that the optimal strategy does not exploit system coherences and is a 'greedy' strategy, in which the purity is increased maximally at each instant.
Gravel, D.; Rilling, A.; Karfik, V.; Schmaeh, M.
1997-12-31
Monitoring extremely low limits of pollutants in the stack emissions of waste incinerators is required by German law (and recently by European Community regulations). This calls for the most advanced and innovative monitoring equipment. Fourier Transform Infrared Spectrometers designed for use in industrial environments can now meet this need. The operating principle and construction of an FTIR-based continuous emissions multicomponent monitoring system will be explained. This FTIR spectrometer provides quantitative results of 9 chemical compounds simultaneously. This number can be increased by simple software addition. The hot/wet, extractive analytical method provides accurate results at extremely low concentration levels for pollutants like HCl, SO{sub 2} and NH{sub 3}, even with up to 60 Vol% water vapor in the gas sample. The combination of FTIR spectrometry and modern chemometrics gives higher selectivity than any other analyzer. The excellent long-term stability allows extending the calibration interval to six months. The ruggedness of industrial grade FTIR Spectrometer and the simple design of the sampling and gas conditioning systems ensure extremely high availability. The performance of the FTIR spectrometer has been validated by an independent products testing organization, TUV Rheinland Germany. The testing includes a laboratory examination and a long term trial under real working conditions. As a result, the FTIR based system Cemas achieved the official permission for emission monitoring by the German Federal Ministry of Environment and Reactor Security. The experience and particular results obtained from the operation of more than 70 FTIR continuous emissions monitoring systems throughout the world will be presented.
Automated drawing system of quantum energy levels
NASA Astrophysics Data System (ADS)
Stampoultzis, M.; Sinatkas, J.; Tsakstara, V.; Kosmas, T. S.
2014-03-01
The purpose of this work is to derive an automated system that provides advantageous drawings of energy spectra for quantum systems (nuclei, atoms, molecules, etc.) required in various physical sciences. The automation involves the development of appropriate computational code and graphical imaging system based on raw data insertion, theoretical calculations and experimental or bibliographic data insertion. The system determines the appropriate scale to depict graphically with the best possible way in the available space. The presently developed code operates locally and the results are displayed on the screen and can be exported to a PostScript file. We note its main features to arrange and visualize in the available space the energy levels with their identity, taking care the existence in the final diagram the least auxiliary deviations. Future improvements can be the use of Java and the availability on the Internet. The work involves the automated plotting of energy levels in molecules, atoms, nuclei and other types of quantized energy spectra. The automation involves the development of an appropriate computational code and graphical imaging system.
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.
Bingham, C.D.
1989-11-01
The U.S. Department of Energy (DOE) order 5633.3, Control and Accountability of Nuclear Materials, initiated substantial changes to the requirements for operations involving nuclear materials. In the opinion of this author, the two most significant changes are the clarification of and the increased emphasis on the concept of graded safeguards and the implementation of performance requirements. Graded safeguards recognizes that some materials are more attractive than others to potential adversary actions and, thus, should be afforded a higher level of integrated safeguards effort. An analytical chemistry laboratory, such as the New Brunswick Laboratory (NBL), typically has a small total inventory of special nuclear materials compared to, for example, a production or manufacturing facility. The NBL has a laboratory information management system (LIMS) that not only provides the sample identification and tracking but also incorporates the essential features of MC A required of NBL operations. As a consequence of order 5633.3, NBL had to modify LIMS to accommodate material attractiveness information for the logging process, to reflect changes in the attractiveness as the material was processed through the laboratory, and to enable inventory information to be accumulated by material attractiveness as the material was processed through the laboratory, and to enable inventory information to be accumulated by material attractiveness codes.
A Multi-Level Middle-Out Cross-Zooming Approach for Large Graph Analytics
Wong, Pak C.; Mackey, Patrick S.; Cook, Kristin A.; Rohrer, Randall M.; Foote, Harlan P.; Whiting, Mark A.
2009-10-11
This paper presents a working graph analytics model that embraces the strengths of the traditional top-down and bottom-up approaches with a resilient crossover concept to exploit the vast middle-ground information overlooked by the two extreme analytical approaches. Our graph analytics model is developed in collaboration with researchers and users, who carefully studied the functional requirements that reflect the critical thinking and interaction pattern of a real-life intelligence analyst. To evaluate the model, we implement a system prototype, known as GreenHornet, which allows our analysts to test the theory in practice, identify the technological and usage-related gaps in the model, and then adapt the new technology in their work space. The paper describes the implementation of GreenHornet and compares its strengths and weaknesses against the other prevailing models and tools.
NASA Astrophysics Data System (ADS)
O'Brien, Chris; Scully, Marlan O.
2016-01-01
In a straightforward manner, we utilize Floquet theory and adiabatic elimination to derive an analytic expression for a monochromatically driven two-level atom, without making the rotating wave approximation. We show that the counter-rotating terms dropped in the rotating wave approximation are responsible for three major effects. First an ac-Stark phase shift of the driven transition, second increased excited state population from far-detuned driving of the Lorentzian line, and third extra frequencies in the population dynamics that result in "wiggles." The analytic result agrees well with numerical simultations over a wide range of parameters.
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 potential curves of some hydride molecules using algebraic and energy-consistent method
NASA Astrophysics Data System (ADS)
Fan, Qunchao; Sun, Weiguo; Feng, Hao; Zhang, Yi; Wang, Qi
2014-01-01
Based on the algebraic method (AM) and the energy consistent method (ECM), an AM-ECM protocol for analytical potential energy curves of stable diatomic electronic states is proposed as functions of the internuclear distance. Applications of the AM-ECM to the 6 hydride electronic states of HF-X1Σ+, DF-X1Σ+, D35Cl-X1Σ+, 6LiH-X1Σ+, 7LiH-X1Σ+, and 7LiD-X1Σ+ show that the AM-ECM potentials are in excellent agreement with the experimental RKR data and the full AM-RKR data, and that the AM-ECM can obtain reliable analytical potential energies in the molecular asymptotic and dissociation region for these molecular electronic states.
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. PMID:23744671
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)
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 ...
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)
Aridogan, U.; Basdogan, I.; Erturk, A.
2014-04-01
Vibration-based energy harvesting using piezoelectric cantilevers has been extensively studied over the past decade. As an alternative to cantilevered harvesters, piezoelectric patch harvesters integrated to thin plates can be more convenient for use in marine, aerospace and automotive applications since these systems are often composed of thin plate-like structures with various boundary conditions. In this paper, we present analytical electroelastic modeling of a piezoelectric energy harvester structurally integrated to a thin plate along with experimental validations. The distributed-parameter electroelastic model of the thin plate with the piezoceramic patch harvester is developed based on Kirchhoff’s plate theory for all-four-edges clamped (CCCC) boundary conditions. Closed-form steady-state response expressions for coupled electrical output and structural vibration are obtained under transverse point force excitation. Analytical electroelastic frequency response functions (FRFs) relating the voltage output and vibration response to force input are derived and generalized for different boundary conditions. Experimental validation and extensive theoretical analysis efforts are then presented with a case study employing a thin PZT-5A piezoceramic patch attached on the surface of a rectangular aluminum CCCC plate. The importance of positioning of the piezoceramic patch harvester is discussed through an analysis of dynamic strain distribution on the overall plate surface. The electroelastic model is validated by a comparison of analytical and experimental FRFs for a wide range of resistive electrical boundary conditions. Finally, power generation performance of the structurally integrated piezoceramic patch harvester from multiple vibration modes is investigated analytically and experimentally.
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. PMID:16607181
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. PMID:22486364
NASA Astrophysics Data System (ADS)
Cai, Huayang; Savenije, Hubert H. G.; Jiang, Chenjuan; Zhao, Lili; Yang, Qingshu
2016-03-01
The mean water level in estuaries rises in the landward direction due to a combination of the density gradient, the tidal asymmetry, and the backwater effect. This phenomenon is more prominent under an increase of the fresh water discharge, which strongly intensifies both the tidal asymmetry and the backwater effect. However, the interactions between tide and river flow and their individual contributions to the rise of the mean water level along the estuary are not yet completely understood. In this study, we adopt an analytical approach to describe the tidal wave propagation under the influence of substantial fresh water discharge, where the analytical solutions are obtained by solving a set of four implicit equations for the tidal damping, the velocity amplitude, the wave celerity, and the phase lag. The analytical model is used to quantify the contributions made by tide, river, and tide-river interaction to the water level slope along the estuary, which sheds new light on the generation of backwater due to tide-river interaction. Subsequently, the method is applied to the Yangtze estuary under a wide range of river discharge conditions where the influence of both tidal amplitude and fresh water discharge on the longitudinal variation of the mean tidal water level is explored. Analytical model results show that in the tide-dominated region the mean water level is mainly controlled by the tide-river interaction, while it is primarily determined by the river flow in the river-dominated region, which is in agreement with previous studies. Interestingly, we demonstrate that the effect of the tide alone is most important in the transitional zone, where the ratio of velocity amplitude to river flow velocity approaches unity. This has to do with the fact that the contribution of tidal flow, river flow, and tide-river interaction to the residual water level slope are all proportional to the square of the velocity scale. Finally, we show that, in combination with extreme
NASA Astrophysics Data System (ADS)
Zharkova, V. V.; Dobranskis, R. R.
2016-06-01
In this paper we consider simultaneous analytical solutions of continuity equations for electron beam precipitation (a) in collisional losses and (b) in ohmic losses, or mixed energy losses (MEL) by applying the iterative method to calculate the resulting differential densities at given precipitation depth. The differential densities of precipitating electrons derived from the analytical solutions for MELs reveal increased flattening at energies below 10-30 keV compared to a pure collisional case. This flattening becomes stronger with an increasing precipitation depth turning into a positive slope at greater precipitation depths in the chromosphere resulting in a differential density distribution with maximum that shifts towards higher energies with increase in column depth, while the differential densities combining precipitating and returning electrons are higher at lower energies than those for a pure collisional case. The resulting hard X-ray (HXR) emission produced by the beams with different initial energy fluxes and spectral indices is calculated using the MEL approach for different ratios between the differential densities of precipitating and returning electrons. The number of returning electrons can be even further enhanced by a magnetic mirroring, not considered in the present model, while dominating at lower atmospheric depths where the magnetic convergence and magnitude are the highest. The proposed MEL approach provides an opportunity to account simultaneously for both collisional and ohmic losses in flaring events, which can be used for a quick spectral fitting of HXR spectra and evaluation of a fraction of returning electrons versus precipitating ones. The semi-analytical MEL approach is used for spectral fitting to Reuven High Energy Solar Spectroscopic Imager observations of nine C, M and X class flares revealing a close fit to the observations and good resemblance to numerical FP solutions.
Analytical potential energy surface for O + C2H2 system
NASA Astrophysics Data System (ADS)
Garashchuk, Sophya; Rassolov, Vitaly A.; Braams, Bastiaan J.
2013-11-01
Full-dimensional analytical potential energy surfaces (PESs) for the O(1P) + C2H2 and O(3P) + C2H2 reactions are presented. The PESs are constructed by fitting thousands of ab initio data points using permutationally invariant polynomials [5]. Electronic structure data are obtained within the restricted coupled cluster theory with single and double excitations with perturbative triple corrections and correlation consistent basis set of triple-ζ with diffuse functions. Motivated by experiments, formation of DOCC and cyclic DCCO at collision energies of 2.5-4 eV is examined using quasi-classical trajectory dynamics on the triplet surface.
Pietri, C.E.; Bracey, J.T.
1985-02-01
Destructive analysis is used by the International Atomic Energy Agency (IAEA) through its Safeguards Analytical Laboratory (SAL) to verify, in part, the inventory of nuclear materials at nuclear facilities. The reliability and quality of these meassurements must be assured in a systematic manner. The Division of Safeguards Evaluation, IAEA, required assistance in developing and implementing the quality assurance measures for the analytical procedures used in the destructive analysis of these safeguards samples. To meet these needs an ISPO POTAS Task D.53 was instituted in which consultants would review with IAEA staff the procedures used (or proposed) at SAL for the destructive analysis of safeguards samples and the statistical evaluation of the resulting measurement data at Headquarters. The procedures included analytical methods, qualtiy control measures, and the treatment of data from these activities. Based on this review, modifications to the system, if required, would be recommended which would provide routine assurance to management that these procedures are functioning properly to achieve safeguards objectives. In the course of this review, the sample handling procedures, measurement control activities, analytical methods, reference materials, calibration procedures, statistical analysis of data, and data management system were studied and evaluated. The degree to which SAL (as a total system) achieved laboratory quality assurance was assessed by comparison to accepted standards of quality assurance. 22 refs., 1 fig.
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 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.
Four energy levels device for skin punching
NASA Astrophysics Data System (ADS)
Savastru, D.; Ristici, Esofina; Mustata, Marina; Miclos, S.; Rusu, M. I.; Radu, C.; Savu, V.
2007-03-01
Generally, the beam distribution in the tissue in interaction with a pulsed laser is defined by optical properties (effective scattering and absorption coefficient). In 2900 nm range, the effective scattering coefficient is much smaller than the absorption coefficient. An Er:YAG skin puncher is presented. Thermal action of a laser beam can be described as one of three types: hyperthermia, coagulation and volatilization, depending on the degree and the duration of tissue heating. We are interested in the volatilization process that means a loss of material. The various constituents of the tissue disappear in smoke at above 100 0C in a relatively short time of around one tenth of a second. At the edges of the volatilization zone there is a region of coagulation necrosis. In presented case of an Er:YAG laser operating in a free generation mode, the mechanical effects can result from explosive vaporization. When the exposure time of the laser is lower than the characteristic time of the thermal diffusion in the tissue, it produces a thermal containment with an accumulation of heat without diffusion and an explosive vaporization of the target. The Er:YAG laser device has the pulse length of about 160 microseconds and four emitted energy levels. This device is used to punch the skin for blood sampling for different kinds of analysis. The front panel of the device has four keys to select the desired energy according to the skin type.
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. PMID:23504620
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
In-source resonance ionization spectroscopy of high lying energy levels in atomic uranium
NASA Astrophysics Data System (ADS)
Raeder, Sebastian; Fies, Silke; Gottwald, Tina; Mattolat, Christoph; Rothe, Sebastian; Wendt, Klaus
2010-02-01
In-source resonance ionization spectroscopy of uranium has been carried out as preparation for the analysis of low contaminations of nuclear material in environmental samples via laser mass spectrometry. Using three-step resonance ionization spectroscopy, 86 levels of odd parity in the energy range from 37,200-38,650 cm - 1 were studied, 51 of these levels were previously unknown. Suitable excitation schemes for analytic applications are discussed.
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. PMID:22237720
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
An analytical description of the atomic information entropy in a multi-level system
NASA Astrophysics Data System (ADS)
Obada, A.-S. F.; Abdel-Aty, Mahmoud
2008-05-01
We construct a complete representation of the atomic information entropy of an arbitrary multi-level system. Our approach is applicable to all scenarios in which the quantum state shared by a single particle and fields is known. As illustrations we apply our findings to a single four-level atom strongly coupled to a cavity field and driven by a coherent laser field. In this framework, we discuss connections with entanglement frustration and entropic forms. We conclude by showing how the atomic information entropy can be extended to examine entanglement in multi-level atomic systems.
Highly accurate analytical energy of a two-dimensional exciton in a constant magnetic field
NASA Astrophysics Data System (ADS)
Hoang, Ngoc-Tram D.; Nguyen, Duy-Anh P.; Hoang, Van-Hung; Le, Van-Hoang
2016-08-01
Explicit expressions are given for analytically describing the dependence of the energy of a two-dimensional exciton on magnetic field intensity. These expressions are highly accurate with the precision of up to three decimal places for the whole range of the magnetic field intensity. The results are shown for the ground state and some excited states; moreover, we have all formulae to obtain similar expressions of any excited state. Analysis of numerical results shows that the precision of three decimal places is maintained for the excited states with the principal quantum number of up to n=100.
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
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. PMID:26840945
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2012 CFR
2012-04-01
... AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS Specific Provisions Relating to Extralabel Use of Animal and Human Drugs in Food-Producing Animals... level for extralabel use of an approved human drug or an approved new animal drug when the agency...
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2014 CFR
2014-04-01
... AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS Specific Provisions Relating to Extralabel Use of Animal and Human Drugs in Food-Producing Animals... level for extralabel use of an approved human drug or an approved new animal drug when the agency...
21 CFR 530.22 - Safe levels and analytical methods for food-producing animals.
Code of Federal Regulations, 2013 CFR
2013-04-01
... AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS Specific Provisions Relating to Extralabel Use of Animal and Human Drugs in Food-Producing Animals... level for extralabel use of an approved human drug or an approved new animal drug when the agency...
Energy levels of a heavy ion moving in dense plasmas
Hu, Hongwei; Chen, Wencong; Zhao, Yongtao; Li, Fuli; Dong, Chenzhong
2013-12-15
In this paper, the potential of a slowly moving test particle moving in collisional dense plasmas is studied. It is composed of the Debye-shielding potential, wake potential, and collision term. The Ritz variational-perturbational method is developed for calculating relativistic binding energy levels of a heavy ion moving in dense plasmas. Binding energy levels of a heavy ion moving in plasmas are calculated. The results show that both non-relativistic energy levels and relativistic energy levels become more negative as the temperature becomes high. They also become more negative as the number density decreasing. Relativistic correction is important for calculating binding energy levels. Both relativistic energy levels and non-relativistic energy levels vary minutely as the speed of heavy ion varies.
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.
Chadalavada, V.; Vittal, V. . Dept. of Electrical Engineering and Computer Engineering)
1994-08-01
Recent developments in direct transient stability assessment using the Transient Energy Function (TEF) method have included the exit point technique to determine the controlling unstable equilibrium point (uep). In this paper, analytical sensitivity of the energy margin is coupled with the exit point based TEF method to assess system stability when there is a change in system parameters: plant generation or network configuration. The principal features of this paper include: introduction of a very fast sensitivity technique to account for network configuration changes, elimination of the assumption that the mode of disturbance of the controlling uep does not change, correlation of the sensitivity results with time simulation through swing curves. The technique is tested on the 50-generator IEEE test system and the 161-generator Northern States Power (NSP) system.
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.
Energy Flux in A-Level Electromagentism.
ERIC Educational Resources Information Center
Adams, S. F.
1988-01-01
Suggests an approach which treats the electric circuit as a channel through which energy flows and to which the application of energy conservation makes the distinction between electromotive force and potential difference unnecessary. Equations, examples, and visual representations are included. (RT)
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.
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.
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. PMID:24815259
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. PMID:17386692
Douglas S. Crawford; Terry A. Ring
2012-12-01
The energy dependent neutron diffusion equation (EDNDE) is converted into a moment equation which is solved analytically for the 1-D problem of a bare sphere of pure 235U. The normalized moments 0–5 generated analytically are compared to normalized energy moments, from Monte Carlo N Particle 5 version 1.40 (MCNP5) and Attila-7.1.0-beta version (Attila). The analytic normalized neutron energy moments, fall between the results from MCNP5 (lower bound) and Attila (upper bound) and are accurate compared to MCNP5 neutron energy moments when error in this Monte Carlo simulation are considered. The error range is from 0% to 14%. The Attila moments are less accurate when compared to MCNP5 than the analytical moments derived in this work. The method of moments is shown to be a fast reliable method, compared to either Monte Carlo methods (MCNP5) or 30 multi-energy group methods (Attila).
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
NASA Astrophysics Data System (ADS)
Dobranskis, Rytis; Zharkova, Valentina
2015-04-01
In this paper we extend the approach presented in Dobranskis & Zharkova (2014a,b) by updating the analytical solutions of continuity equation (CE) for pure Ohmic losses and developing a method for analytical solutions to account simultaneously for both collisional and Ohmic losses. The exact solutions of CE for electron density of the beams precipitating in Ohmic losses are found at different precipitation depths for precipitating and "returning") electrons. Then the iterative process was applied to calculate the differential density for mixed (Ohmic and collisional) energy losses (MEL). The differential densities obtained from the updated CE for Coulomb collisions and MEL are used to calculate the HXR intensity for relativistic cross-section and to compare the outcome with more accurate results found from the numerical Fokker-Planck (FP) solution for the same collisional and Ohmic losses. The HXR intensity distribution produced by MEL solution reveals a close resemblance to the results from the numerical FP solution, being almost identical for weaker soft electron beams. However, the MEL simulation can be run up to 30 times faster than the numerical FP. This method implemented in IDL is to be incorporated into the RHESSI software that can be used for quick estimation of the effect of Ohmic losses versus collisions from the RHESSI data.
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 Technical Reports Server (NTRS)
Lee, Timothy J.; Rendell, Alistair P.
1991-01-01
An efficient formulation of the analytic energy gradient for the single and double excitation coupled-cluster method that includes a perturbational estimate of the effects of connected triple excitations is presented. The formulation has a small computational cost, and the algebraic manipulations may be applied generally to the analytic gradient of Moller-Plesset perturbation theory energies. The new formulation has been implemented in an efficient set of programs that utilize highly vectorized algorithms and has been used to investigate the equilibrium structures, harmonic vibrational frequencies, IR intensities, and energy separation of cis- and trans-HONO.
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.
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…
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.
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.
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
An analytic model for interacting dark energy and its observational constraints
NASA Astrophysics Data System (ADS)
Pan, Supriya; Bhattacharya, Subhra; Chakraborty, Subenoy
2015-09-01
The paper deals with a theoretical model for interacting dark energy (DE). The interaction between the cold dark matter (dust) and the DE has been assumed to be non-gravitational in nature. Exact analytic cosmological solutions are obtained both for constant and variable EoS for DE. It is found that, for very small value of the coupling parameter (in the interaction term), the model asymptotically extends up to Λ cold dark matter, while the model can enter into the phantom domain asymptotically, if the coupling parameter is not so small. Both the solutions are then analysed with 194 Supernovae Type Ia data. The best-fitting parameters are shown with 1σ and 2σ confidence intervals. Finally, we have discussed the cosmographic parameters for both the cases.
Analytical energy-barrier-dependent Voc model for amorphous silicon solar cells
NASA Astrophysics Data System (ADS)
Castro-Carranza, A.; Nolasco, J. C.; Reininghaus, N.; Geißendörfer, S.; Vehse, M.; Parisi, J.; Gutowski, J.; Voss, T.
2016-07-01
We show that the open circuit voltage (Voc) in hydrogenated amorphous silicon (a-Si:H) solar cells can be described by an analytical energy-barrier-dependent equation, considering thermionic emission as the physical mechanism determining the recombination current. For this purpose, the current-voltage characteristics of two device structures, i.e., a-Si:H(n)/a-Si:H(i)/a-Si:H(p)/AZO p-i-n solar cells with different p-doping concentrations and a-Si:H(n)/a-Si:H(i)/AZO Schottky structures with different intrinsic layer thicknesses, were analyzed in dark and under illumination, respectively. The calculated barrier in the p-i-n devices is consistent with the difference between the work function of the p-layer and the conduction band edge of the i-layer at the interface in thermal equilibrium.
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.
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
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.
Wiemers, K.D.; Miller, M.; Lerchen, M.E.
1999-01-04
Radiation levels, salt concentration, and the oxidizing nature of the waste dictates modifications to the SW-846 methods. Modified methods will be used to meet target EQLs and QC currently in SW-846. Method modifications will be validated per SW-846 and HASQARD and will be documented consistent with WAC 173-303-910. The affect of modifications to holding times and storage conditions will be evaluated using techniques developed by Maskarinec and Bayne (1996). After validating the methods and performing the holding time study on a minimum of two Phase 1 candidate feed source tank wastes, DOE and Ecology will assess: whether different methods are needed, whether holding time/storage conditions should be altered, whether the high priority analyte list should be refined, and which additional tank waste needs to be characterized.
NASA Astrophysics Data System (ADS)
Kuhn, Bernd; Rizzo, Thomas R.; Luckhaus, David; Quack, Martin; Suhm, Martin A.
1999-08-01
We report calculations of the electronic ground state potential energy surface (PES) of hydrogen peroxide covering, in an almost global fashion, all six internal degrees of freedom by two different ab initio techniques. Density functional theory (DFT) calculations using the Becke 3 parameter Lee-Yang-Parr (B3LYP) hybrid functional and multiconfigurational second order perturbation theory (CASPT2) calculations, both using large basis sets, are performed for a wide range of geometries (8145 DFT and 5310 CASPT2 single-point energies). We use a combined data set of mostly DFT with additional CASPT2 ab initio points and the complete CASPT2 surface to fit a total of four different 6D analytical representations. The resulting potentials contain 70-76 freely adjusted parameters and represent the ground state PES up to 40000 cm-1 above the equilibrium energy with a standard deviation of 100-107 cm-1 without any important artifacts. One of the model surfaces is further empirically refined to match the bond dissociation energy D0 for HOOH→2OH . The potentials are designed for energy regions accessible by vibrational fundamental and overtone spectroscopy including the dissociation channel into hydroxyl radicals. Characteristic properties of the model surfaces are investigated by means of stationary point analyses, torsional barrier heights, harmonic frequencies, low-dimensional cuts and minimum energy paths for dissociation. Overall good agreement with high-level ab initio calculations, especially for the CASPT2 based potentials, is achieved. The drastic change in geometry at intermediate O-O distances, which reflects the transition from covalent to hydrogen bonding, is reproduced quantitatively. We calculate fully 6D anharmonic zero point energies and ground state torsional splittings with the diffusion quantum Monte Carlo method in perfect agreement, within statistical error bars, with experiment for the CASPT2 based potentials. Variational vibrational calculations in the
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.
Quantum adiabatic evolution with energy degeneracy levels
NASA Astrophysics Data System (ADS)
Zhang, Qi
2016-01-01
A classical-kind phase-space formalism is developed to address the tiny intrinsic dynamical deviation from what is predicted by Wilczek-Zee theorem during quantum adiabatic evolution on degeneracy levels. In this formalism, the Hilbert space and the aggregate of degenerate eigenstates become the classical-kind phase space and a high-dimensional subspace in the phase space, respectively. Compared with the previous analogous study by a different method, the current result is qualitatively different in that the first-order deviation derived here is always perpendicular to the degeneracy subspace. A tripod-scheme Hamiltonian with two degenerate dark states is employed to illustrate the adiabatic deviation with degeneracy levels.
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.
NASA Astrophysics Data System (ADS)
Loveridge, A. J.; van der Sluys, M. V.; Kalogera, V.
2011-12-01
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 = 10-4 and Z = 0.03 and masses between 0.8 M ⊙ and 100 M ⊙, 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 >~ 50 M ⊙), when stars lose more than ~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.
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.
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.
ORNL takes energy-efficient housing to a new level
None
2010-01-08
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
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.
Neudorf, Cory; Fuller, Daniel; Cushon, Jennifer; Glew, Riley; Turner, Hollie; Ugolini, Cristina
2015-01-01
Background: We present the health inequalities analytic approach used by the Saskatoon Health Region to examine health equity. Our aim was to develop a method that will enable health regions to prioritize action on health inequalities. Methods: Data from admissions to hospital, physician billing, reportable diseases, vital statistics and childhood immunizations in the city of Saskatoon were analyzed for the years ranging from 1995 to 2011. Data were aggregated to the dissemination area level. The Pampalon deprivation index was used as the measure of socioeconomic status. We calculated annual rates per 1000 people for each outcome. Rate ratios, rate differences, area-level concentration curves and area-level concentration coefficients quantified inequality. An Inequalities Prioritization Matrix was developed to prioritize action for the outcomes showing the greatest inequality. The outcomes measured were cancer, intentional self-harm, chronic obstructive pulmonary disease, mental illness, heart disease, diabetes, injury, stroke, chlamydia, tuberculosis, gonorrhea, hepatitis C, high birth weight, low birth weight, teen abortion, teen pregnancy, infant mortality and all-cause mortality. Results: According to the Inequalities Prioritization Matrix, injuries and chronic obstructive pulmonary disease were the first and second priorities, respectively, that needed to be addressed related to inequalities in admissions to hospital. For physician billing, mental disorders and diabetes were high-priority areas. Differences in teen pregnancy and all-cause mortality were the most unequal in the vital statistics data. For communicable diseases, hepatitis C was the highest priority. Interpretation: Our findings show that health inequalities exist at the local level and that a method can be developed to prioritize action on these inequalities. Policies should consider health inequalities and adopt population-based and targeted actions to reduce inequalities. PMID:27022600
Chang, L.K.; Mohr, D.; Feldman, E.E.; Betten, P.R.; Planchon, H.P.
1985-01-01
A series of eight loss-of-flow (LOF) tests have been conducted in EBR-II to study the transition between forced and natural convective flows following a variety of loss-of-primary-pumping power conditions from decay heat levels. Comparisons of measurements and pretest/posttest predictions were made on a selected test. Good agreements between measurements and predictions was found prior to and just after the flow reaching its minimum, but the agreement is not as good after that point. The temperatures are consistent with the flow response and the assumed decay power. The measured results indicate that the flows of driver and the instrumented subassemblies are too much in the analytical model in the natural convective region. Although a parametric study on secondary flow, turbulent-laminar flow transition, heat transfer ability of the intermediate heat exchange at low flow and flow mixing in the primary tank has been performed to determine their effects on the flow, the cause of the discrepancy at very low flow level is still unknown.
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.
Revised energy levels and hyperfine structure constants of Ta II
NASA Astrophysics Data System (ADS)
Windholz, Laurentius; Arcimowicz, Bronislaw; Uddin, Zaheer
2016-06-01
Using a wave number calibrated Fourier transform spectrum, we determined the energy levels of the first ion of tantalum with high accuracy. To get the correct center of gravity wave numbers of the observed spectral lines, the knowledge of the hyperfine constants of the involved levels was necessary. From the observed values we deduced the energy levels in a global fit. A comparison between our results and all available literature values is presented.
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.
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.
Theory of Energy Level Tuning in Quantum Dots by Surfactants
NASA Astrophysics Data System (ADS)
Zherebetskyy, Danylo; Wang, Lin-Wang; Materials Sciences Division, Lawrence Berkeley National Laboratory Team
2015-03-01
Besides quantum confinement that provides control of the quantum dot (QD) band gap, surface ligands allow control of the absolute energy levels. We theoretically investigate energy level tuning in PbS QD by surfactant exchange. We perform direct calculations of real-size QD with various surfactants within the frame of the density functional theory and explicitly analyze the influence of the surfactants on the electronic properties of the QD. This work provides a hint for predictable control of the absolute energy levels and their fine tuning within 3 eV range by modification of big and small surfactants that simultaneously passivate the QD surface.
Guo, Shaojun; Dong, Shaojun
2011-05-01
The emergence of graphene nanosheet (GN, 2010 Nobel Prize for Physics) has recently opened up an exciting new field in the science and technology of two-dimensional (2D) nanomaterials with continuously growing academic and technological impetus. GN exhibits unique electronic, optical, magnetic, thermal and mechanical properties arising from its strictly 2D structure and thus has many important technical applications. Actually, GN-based materials have enormous potential to rival or even surpass the performance of carbon nanotube-based counterparts, given that cheap, large-scale production and processing methods for high-quality GN become available. Therefore, the studies on GN in the aspects of chemistry, physical, materials, biology and interdisciplinary science have been in full flow in the past five years. In this critical review, from the viewpoint of chemistry and materials, we will cover recent significant advances in synthesis, molecular engineering, thin film, hybrids, and energy and analytical applications of the "star-material" GN together with discussion on its major challenges and opportunities for future GN research (315 references). PMID:21283849
Thompson, Andrew R; Donnison, Jenny; Warnock-Parkes, Emma; Turpin, Graham; Turner, James; Kerr, Ian B
2008-04-01
This study sought to explore community mental health teams' (CMHTs) experiences of receiving an innovative introductory level training in cognitive analytic therapy (CAT). CMHTs are important providers of care for people with mental health problems. Although CMHTs have many strengths, they have been widely criticized for failing to have a shared model underlying practice. Inter-professional training which develops shared therapeutic models from which to plan care delivery is, therefore, essential. We have been developing such a training based on the psychotherapeutic principles of CAT. Twelve community mental health staff (six mental health social workers and six community psychiatric nurses) were interviewed by an independent interviewer following the completion of the training programme. The interviews were analysed using a qualitative thematic analysis. The analysis revealed that the programme increased the participants' self-assessed therapeutic confidence and skill and fostered the development of a shared model within the team, although the training was also perceived as adding to workload. The results of this study suggest that whole-team CAT training may facilitate cohesion and also suggest that having some shared common language is important in enabling and supporting work with 'difficult' and 'complex' clients, for example, those with personality disorders. Further development of such training accompanied by rigorous evaluation should be undertaken. PMID:18307602
NASA Astrophysics Data System (ADS)
Daeppen, W.
1980-11-01
In the free energy method statistical mechanical models are used to construct a free energy function of the plasma. The equilibrium composition for given temperature and density is found where the free energy is a minimum. Until now the free energy could not be expressed analytically, because the contributions from the partially degenerate electrons and from the inner degrees of freedom of the bound particles had to be evaluated numerically. In the present paper further simplifications are made to obtain an analytic expression for the free energy. Thus the minimum is rapidly found using a second order algorithm, whereas until now numerical first order derivatives and a steepest- descent method had to be used. Consequently time-consuming computations are avoided and the analytical version of the free energy method has successfully been incorporated into the stellar evolution programmes at Geneva Observatory. No use of thermodynamical tables is made, either. Although some accuracy is lost by the simplified analytical expression, the main advantages of the free energy method over simple ideal-gas and Sacha-equation subprogrammes (as used in the stellar programmes mentioned) are still kept. The relative errors of the simplifications made here are estimated and they are shown not to exceed 10% altogether. Densities up to those encountered in low-mass main-sequence stars can be treated within the region of validity of the method. Higher densities imply less accurate results. Nonetheless they are consistent so that they cannot disturb the numerical integration of the equilibrium equation in the stellar evolution model. The input quantities of the free energy method presented here are either temperature and density or temperature and pressure, the latter require a rapid numerical Legendre transformation which has been developed here.
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.
NASA Astrophysics Data System (ADS)
Emfietzoglou, D.; Kyriakou, I.; Garcia-Molina, R.; Abril, I.; Kostarelos, K.
2010-09-01
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.
"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)
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)
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.
New Fe ii energy levels from stellar spectra
NASA Astrophysics Data System (ADS)
Castelli, F.; Kurucz, R. L.
2010-09-01
Aims: The spectra of B-type and early A-type stars show numerous unidentified lines in the whole optical range, especially in the 5100-5400 Å interval. Because Fe ii transitions to high energy levels should be observed in this region, we used semiempirical predicted wavelengths and gf-values of Fe ii to identify unknown lines. Methods: Semiempirical line data for Fe ii computed by Kurucz are used to synthesize the spectrum of the slow-rotating, Fe-overabundant CP star HR 6000. Results: We determined a total of 109 new 4f levels for Fe ii with energies ranging from 122 324 cm-1 to 128 110 cm-1. They belong to the Fe ii subconfigurations 3d6(3P)4f (10 levels), 3d6(3H)4f (36 levels), 3d6(3F)4f (37 levels), and 3d6(3G)4f (26 levels). We also found 14 even levels from 4d (3 levels), 5d (7 levels), and 6d (4 levels) configurations. The new levels have allowed us to identify more than 50% of the previously unidentified lines of HR 6000 in the wavelength region 3800-8000 Å. Tables listing the new energy levels are given in the paper; tables listing the spectral lines with log gf ≥ -1.5 that are transitions to the 4f energy levels are given in the Online Material. These new levels produce 18 000 lines throughout the spectrum from the ultraviolet to the infrared. Tables 6-9 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/520/A57
Calibration of Electric Field Induced Energy Level Shifts in Argon
NASA Astrophysics Data System (ADS)
Hebner, Greg
1999-10-01
Argon is a commonly used gas in a number of discharges. As such it is an ideal candidate for spectroscopic based electric field measurements within the sheath and bulk discharge regions. Recently, measurements demonstrated the use of the Stark induced shifts of high lying energy levels in Argon to make spatially and temporally resolved electric field measurements [1]. However, that method relied on the cross calibration of known and calculable shifts in helium discharges to calibrate, in-situ, the energy level shifts in Argon. This poster shows the use of an atomic beam system to calibrate the electric field induced shift of high lying energy levels directly. In addition, data on very high lying argon levels, up to the 20 F manifold, were obtained. Comparison of our electric field induced energy level shift calibration curves with previous work will be shown. The possibility of using this system to calibrate energy level shifts in other gases of technological interest to the microelectronics and lighting industry will be discussed. [1]. J. B. Kim, K. Kawamura, Y. W. Choi, M. D. Bowden, K. Muraoka and V. Helbig, IEEE Transactions on Plasma Science, 26(5), 1556 (1998). This work was performed at Sandia National Laboratories and supported by the United States Department of Energy (DE-AC04-94AL85000).
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)
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
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.
High-level ab initio potential energy surfaces and vibrational energies of H2CS
NASA Astrophysics Data System (ADS)
Yachmenev, Andrey; Yurchenko, Sergei N.; Ribeyre, Tristan; Thiel, Walter
2011-08-01
Six-dimensional (6D) potential energy surfaces (PESs) of H2CS have been generated ab initio using the recently proposed explicitly correlated (F12) singles and doubles coupled cluster method including a perturbational estimate of connected triple excitations, CCSD(T)-F12b [T. B. Adler, G. Knizia, and H.-J. Werner, J. Chem. Phys. 127, 221106 (2007)] in conjunction with F12-optimized correlation consistent basis sets. Core-electron correlation, high-order correlation, scalar relativistic, and diagonal Born-Oppenheimer terms were included as additive high-level (HL) corrections. The resulting 6D PESs were represented by analytical functions which were used in variational calculations of the vibrational term values below 5000 cm-1. The best PESs obtained with and without the HL corrections, VQZ-F12* HL and VQZ-F12*, reproduce the fundamental vibrational wavenumbers with mean absolute deviations of 1.13 and 1.22 cm-1, respectively. A detailed analysis of the effects of the HL corrections shows how the VQZ-F12 results benefit from error cancellation. The present purely ab initio PESs will be useful as starting points for empirical refinements towards an accurate "spectroscopic" PES of H2CS.
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.
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.
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. PMID:27530803
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.
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…
Energy levels and radiative transition rates for Ba XLVIII
NASA Astrophysics Data System (ADS)
Khatri, Indu; Goyal, Arun; Aggarwal, Sunny; Singh, A. K.; Mohan, Man
2016-01-01
Energy levels and radiative rates are reported for transitions in F-like Ba XLVIII. Configuration interaction has been included among 27 configurations (generating 431 levels) over a wide energy range up to 618 Rydbergs, and the fully relativistic multi-configurational Dirac-Fock method adopted for the calculations. To assess the accuracy, calculations have also been performed with the flexible atomic code, FAC. Radiative rates, oscillator strengths and line strengths are reported for all electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions from the lowest 3 levels, although calculations have been performed for a much larger number of levels. We have made comparisons of our results with existing available results and a good agreement has been achieved. Additionally, lifetimes for all 431 levels are listed.
NASA Astrophysics Data System (ADS)
Monge-Palacios, M.; Corchado, J. C.; Espinosa-Garcia, J.
2013-06-01
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)], 10.1063/1.4792719. 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 (Ecoll ≥ 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.
NASA Astrophysics Data System (ADS)
Shi, De-Heng; Liu, Yu-Fang; Sun, Jin-Feng; Zhu, Zun-Lue; Yang, Xiang-Dong
2006-12-01
The reasonable dissociation limit of the second excited singlet state B1Π of 7LiH molecule is obtained. The accurate dissociation energy and equilibrium geometry of the B1Π state are calculated using a symmetry-adapted-cluster configuration-interaction method in full active space. The whole potential energy curve for the B1Π state is obtained over the internuclear distance ranging from about 0.10 nm to 0.54 nm, and has a least-square fit to the analytic Murrell-Sorbie function form. The vertical excitation energy is calculated from the ground state to the B1Π state and compared with previous theoretical results. The equilibrium internuclear distance obtained by geometry optimization is found to be quite different from that obtained by single-point energy scanning under the same calculation condition. Based on the analytic potential energy function, the harmonic frequency value of the B1Π state is estimated. A comparison of the theoretical calculations of dissociation energies, equilibrium interatomic distances and the analytic potential energy function with those obtained by previous theoretical results clearly shows that the present work is more comprehensive and in better agreement with experiments than previous theories, thus it is an improvement on previous theories.
Global Sea Level Rise and the Earth's Energy Balance
NASA Astrophysics Data System (ADS)
Willis, J.; Hobbs, W. R.
2012-12-01
As the oceans warm due to human-caused climate change, they contribute to both global and regional sea level rise. But the uptake of heat by the ocean also reflects the net radiative imbalance of the planet due to human interference with the climate. Global sea level rise and its components therefore provide a constraint on the Earth's Energy Balance, and vice versa. We will present an assessment of the sea level and energy budgets and their implications for the magnitude of deep ocean warming and net radiative forcing over the past decade. Observations from satellite altimeters and the GRACE gravity mission will be compared with in situ observations of ocean warming. In addition, we will consider observations from the Clouds and the Earth's Radiant Energy System (CERES) instruments to assess the Earth's net radiation balance. Finally, a new estimate of bias corrections for the XBT observations will be assessed and presented.
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.
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. PMID:27041512
Electronic energy levels of intermediates in the laboratory
NASA Astrophysics Data System (ADS)
Howard, I. A.; Horlick, G.
1980-12-01
Using the multiple scattering X-alpha method, electronic energy levels have been found self-consistently for the intermediates Ni(CO)(n), n = 1,2,3 in the formation of nickel tetracarbonyl via the Ni-CO surface reaction. Linear geometries have been assumed for NiCO and Ni(CO)2, and a trigonal planar conformation for Ni(CO)3, in accordance with previously published IR spectra. The intermediates were assumed to be in the gas phase, free of surface interaction. From the energy level structure found, all three of the intermediates were determined to be diamagnetic, as Ni(CO)4 is known to be.
Electronic energy levels of intermediates in the nickel carbonylation reaction
NASA Astrophysics Data System (ADS)
Howard, I. A.; Pratt, G. W.; Johnson, K. H.; Dresselhaus, G.
1981-03-01
Using the multiple scattering Xa method, electronic energy levels have been found self-consistently for the intermediates Ni(CO)n, n = 1,2,3 in the formation of nickel tetracarbonyl via the Ni-CO surface reaction. Linear geometries have been assumed for NiCO and Ni(CO)2, and a trigonal planar conformation for Ni(CO)3, in accordance with previously published IR spectra. The intermediates were assumed to be in the gas phase, free of surface interaction. From the energy level structure found, all three of the intermediates were determined to be diamagnetic, as Ni(CO)4 is known to be.
Energy levels, lifetimes and radiative data of Ba XXVI
NASA Astrophysics Data System (ADS)
Singh, A. K.; Goyal, Arun; Khatri, Indu; Aggarwal, Sunny; Sharma, Rinku; Mohan, Man
2016-05-01
We report an extensive and an elaborate theoretical study of atomic data for Ba XXVI by considering Singlet, Doublet and Triplet (SDT) electron excitations within N-shell and single excitations from N-shell to O-shell. We have calculated energy levels and lifetimes for lowest 110 fine structure levels by using Multi-configuration Dirac-Fock method (MCDF). We have also considered Quantum Electrodynamics (QED) and Breit corrections in our calculations. We have presented the radiative data for electric and magnetic dipole (E1, M1) and quadrupole (E2, M2) transitions among lowest 110 levels. We have made comparisons of our calculated excitation energies and EUV (Extreme Ultraviolet) transition wavelengths with experimentally observed energy levels and wavelengths and achieved good agreement. We have also computed energy levels by performing similar relativistic distorted wave calculations using Flexible Atomic Code (FAC). Additionally, we have provided new atomic data for Ba XXVI which are not published elsewhere in the literature. We believe that our results may be beneficial in fusion plasma research and astrophysical investigations and applications.
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
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)
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.
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. PMID:26890276
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.
S-matrix calculations of energy levels of alkalilike ions
NASA Astrophysics Data System (ADS)
Sapirstein, Jonathan; Cheng, K. T.
2013-05-01
A recent S-matrix based QED calculation of energy levels of the lithium isoelectronic sequence is extended to the general case of a valence electron outside an arbitrary filled core. Formulas are presented that allow calculation of the energy levels of valence ns , np1 / 2 , np3 / 2 , nd3 / 2 , and nd5 / 2 states. Emphasis is placed on modifications of the lithiumlike formulas required because more than one core state is present, and a discussion of an unusual feature of the two-photon exchange contribution involving autoiononizing states is given. The method is illustrated with a calculation of energy levels of the sodium isoelectronic sequence, with results for 3s1 / 2 , 3p1 / 2 , and 3p3 / 2 energies tabulated for the range Z = 20 - 100 . A detailed breakdown of the calculation is given for Z = 74 . Comparison with experiment and other calculations is given, and prospects for extension of the method to ions with more complex electronic structure discussed. The work of JS was supported in part by NSF Grant No. PHY-1068065. The work of KTC was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
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
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).
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.
Interaction Determined Electron Energy Levels in One-Dimension
NASA Astrophysics Data System (ADS)
Pepper, Michael; Kumar, Sanjeev; Thomas, Kalarikad; Smith, Luke; Creeth, Graham; Farrer, Ian; Ritchie, David; Jones, Geraint; Jonathan, Griffiths; UCL Collaboration; Cavendish Laboratory Collaboration
2015-03-01
We have investigated electron transport in a quasi-one dimensional electron gas in the GaAs-AlGaAs heterostructure designed so that the confinement potential can be progressively weakened. This causes the energy levels to decrease in energy relative to each other, however this decrease occurs at different rates, a feature attributed to the energy being determined by both confinement and the electron-electron repulsion which varies with the shape of the wavefunction. It is found that the initial ground state crosses the higher levels so resulting in missing plateaux of quantised conductance. A change in the nature of the ground state to a more extended form causes an increase in the capacitance between the confining gates and the electrons. Both crossings and anti-crossings of the levels are found and these will be discussed along with other consequences of the form of the level interactions. The effects of level crossing on the spin dependent 0.7 structure will be presented. Supported by EPSRC (UK).
Spectrum and energy levels of kryptonlike ion Nb VI
Reader, J.; Ekberg, J.O.
1993-05-01
The spectrum of five-times ionized niobium, Nb, VI, was observed from 238 to 2700 {angstrom} with sliding spark discharges on 10.7-m normal- and grazing-incidence spectrographs. Experimental energies were determined for all levels of the 4s{sup 2}4p{sup 6}, 4s{sup 2}4p{sup 6}, 4s{sup 2}4p{sup 5}4d, 4f, 5s, 5p, 5g, 6s, and 4s4p{sup 6}4d configurations as well as some levels of 4p{sup 5}6g. A total of 291 lines were classified as transitions between 88 observed levels. A previous analysis of this spectrum was found to be totally erroneous. Large hyperfine splittings were found for several levels of the 4p{sup 5}5s and 5p configurations. The observed configurations were theoretically interpreted by means of Hartree-Fock calculations and least squares fits of the energy parameters to the observed levels. A revised value of the ionization energy was obtained from the 4p{sup 5}5g and 6g configurations.
NASA Astrophysics Data System (ADS)
Zou, Wenli; Filatov, Michael; Cremer, Dieter
2011-06-01
The analytical energy gradient of the normalized elimination of the small component (NESC) method is derived for the first time and implemented for the routine calculation of NESC geometries and other first order molecular properties. Essential for the derivation is the correct calculation of the transformation matrix U relating the small component to the pseudolarge component of the wavefunction. The exact form of {partial {U}}/{partial λ } is derived and its contribution to the analytical energy gradient is investigated. The influence of a finite nucleus model and that of the picture change is determined. Different ways of speeding up the calculation of the NESC gradient are tested. It is shown that first order properties can routinely be calculated in combination with Hartree-Fock, density functional theory (DFT), coupled cluster theory, or any electron correlation corrected quantum chemical method, provided the NESC Hamiltonian is determined in an efficient, but nevertheless accurate way. The general applicability of the analytical NESC gradient is demonstrated by benchmark calculations for NESC/CCSD (coupled cluster with all single and double excitation) and NESC/DFT involving up to 800 basis functions.
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.
NASA Astrophysics Data System (ADS)
Yeh, Hund-Der; Chuang, Mo-Hsiung
2014-05-01
Tide-induced head fluctuation in a two-dimensional estuarine aquifer system is complicated and rather important in dealing with many groundwater management or remediation problems. The conceptual model of the aquifer system we considered is anisotropic, multi-layered with a bending estuarine bank, and subject to the tidal fluctuation effects from both the sea shore and estuarine river. The solution of the model describing the groundwater head distribution in such a coastal aquifer system is developed based on the method of separation of variables and a coordinate transformation applied to the river boundary at the bend with an angle of arbitrary degree to the line perpendicular to the sea shore. The solutions by Sun (Sun H. A two-dimensional analytical solution of groundwater response to tidal loading in an estuary, Water Resour. Res. 1997; 33:1429-35) as well as Tang and Jiao (Tang Z. and J. J. Jiao, A two-dimensional analytical solution for groundwater flow in a leaky confined aquifer system near open tidal water, Hydrological Processes, 2001; 15: 573-585) can be shown to be special cases of the present solution if the degree of the bending angle is zero. On the basis of the analytical solution, the groundwater head distribution in response to estuarine boundary is examined and the influences of anisotropy, leakage, hydraulic parameters, and bending angle on the groundwater head fluctuation are investigated and discussed.
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.
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 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
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 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.
Determination of the nuclear level density at high excitation energy
Chbihi, A.; Sobotka, L.G.; Nicolis, N.G.; Sarantites, D.G.; Stracener, D.W.; Majka, Z. ); Hensley, D.C.; Beene, J.R.; Halbert, M.L. )
1991-02-01
Evaporation simulations are presented to illustrate the problems associated with the determination of the nuclear level density constant at high excitation energy from evaporation spectra. The methods of using either the total (whole chain) spectra or the difference (from two different initial excitation energies) spectra are discussed. Data from the study of the reaction 701 MeV {sup 28}Si+{sup 100}Mo are presented and both methods are used to extract the level density constant. We find that in order to reproduce the slopes of the light particle spectra the level density constant must have a value near 1/10{ital A}-- 1 / 11 {ital A} for excited nuclei with statistical temperatures in the range of 3.5 to 5.5 MeV. This presumes that the only parameter adjustment required to treat the decay of highly exited nuclei is the level density constant. If this is so, the shapes of the evaporation spectra imply a reduction in the level density constant from the value required to explain the decay of less highly excited nuclei, a conclusion reached by others. However, the reduced level density constant leads to an overproduction of deuterons and tritons. This suggests that a more complicated set of parameter adjustments may be required to treat the decay of highly excited nuclei.
Core level binding energies of functionalized and defective graphene.
Susi, Toma; Kaukonen, Markus; Havu, Paula; Ljungberg, Mathias P; Ayala, Paola; Kauppinen, Esko I
2014-01-01
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
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
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
Electron Energy Levels in the 1D-2D Transition
NASA Astrophysics Data System (ADS)
Pepper, Michael; Sanjeev, Kumar; Thomas, Kalarikad; Creeth, Graham; English, David; Ritchie, David; Griffiths, Jonathan; Farrer, Ian; Jones, Geraint
Using GaAs-AlGaAs heterostructures we have investigated the behaviour of electron energy levels with relaxation of the potential confining a 2D electron gas into a 1D configuration. In the ballistic regime of transport, when the conductance shows quantized plateaux, different types of behaviour are found according to the spins of interacting levels, whether a magnetic field is applied and lifting of the momentum degeneracy with a source-drain voltage. We have observed both crossing and anti-crossing of levels and have investigated the manner in which they can be mutually converted. In the presence of a magnetic field levels can cross and lock together as the confinement is altered in a way which is characteristic of parallel channels. The overall behaviour is discussed in terms of electron interactions and the wavefunction flexibility allowed by the increasing two dimensionality of the electron distribution as the confinement is weakened. Work supported by UK EPSRC.
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 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.
Energy level offset analysis of lead atom in laser plasma
NASA Astrophysics Data System (ADS)
Zhou, X. M.; Chen, C. S.; Man, B. Y.; Guo, J.; Wang, J.
2009-08-01
The optical emission spectra of the plasma generated by a 1064 nm laser irradiation of lead target in air were recorded and analyzed. Temporal evolvement trait of spectral lines was investigated. The Stark width and line shift were measured at different delay time and laser energies. The electron densities were determined using Stark-broadening parameters of spectral lines. The atomic energy level offset in plasma surroundings was explored by analyzing the line shift. The experimental data of Stark widths and line shifts were analyzed using the regularity of the Stark parameters’ dependence on effective ionization potential. However an inverse experimental result was found compared with the theoretical calculation. In addition, the change of the Stark widths and line shifts with the delay time and laser energies was discussed.
Energy level modeling of lanthanide materials: review and uncertainty analysis.
Joos, Jonas J; Poelman, Dirk; Smet, Philippe F
2015-07-15
Energy level schemes are an essential tool for the description and interpretation of atomic spectra. During the last 40 years, several empirical methods and relationships were devised for constructing energy level schemes of lanthanide defects in wide band gap solids, culminating in the chemical shift model by Thiel and Dorenbos. This model allows us to calculate the electronic and optical properties of the considered materials. However, an unbiased assessment of the accuracy of the obtained values of the calculated parameters is still lacking to a large extent. In this paper, error margins for calculated electronic and optical properties are deduced. It is found that optical transitions can be predicted within an acceptable error margin, while the description of phenomena involving conduction band states is limited to qualitative interpretation due to the large error margins for physical observables such as thermal quenching temperature, corresponding to standard deviations in the range 0.3-0.5 eV for the relevant energy differences. As an example, the electronic structure of lanthanide doped calcium thiogallate (CaGa2S4) is determined, taking the experimental spectra of CaGa2S4:Ln(Q+) (Ln(Q+) = Ce(3+), Eu(2+), Tm(3+)) as input. Two different approaches to obtain the shape of the zig-zag curves connecting the 4f levels of the different lanthanides are explored and compared. PMID:26129935
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.
Examining the energy cost and intensity level of prenatal yoga
Peters, Nathan Anthony; Schlaff, Rebecca A
2016-01-01
Context: A popular form of pregnancy physical activity (PA) is prenatal yoga. However, little is known about the intensity and energy cost of this practice. Aims: To examine the energy cost and intensity level of prenatal yoga. Methods: 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. Results: 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. Conclusions: 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. PMID:26865776
Analytical yield spectrum approach to electron energy degradation in earth's atmosphere
NASA Astrophysics Data System (ADS)
Haider, S. A.; Singhal, R. P.
1983-09-01
The analytical yield spectrum approach developed by Green et al. (1977) and Jackman and Green (1979) and extended by Singhal et al. (1980) and Singhal and Green (1981) is used to calculate the electron flux, excitation, and ionization profiles. The method, as applied in its full detail to the earth's atmosphere, is introduced, and the results it yields are compared with those obtained by Banks et al. (1974) and Mantas and Walker (1976). With regard to excitation, good agreement with the results of Mantas and Walker is found as far as the position of the peak is concerned. At low altitudes, the results obtained here show a gradual fall off of the excitation rate; this is in contrast to the sharp cutoff obtained by Mantas and Walker. A possible reason for this is that the present results are based on Monte Carlo studies in which the electrons are followed down to the lowest excitation threshold. This leads to more straggling. Another reason for the low altitude tail may involve the use of smooth analytical functions.
NASA Astrophysics Data System (ADS)
Li, Ming; Kapusta, Joseph I.
2016-08-01
We generalize calculations of the energy-momentum tensor for classical gluon fields in the boost-invariant McLerran-Venugopalan model using the small-τ power series expansion method. Results to all orders for the energy density and pressures are given in the leading Q2 approximation and with the inclusion of estimated running coupling effects. The energy density and transverse pressure decrease monotonically with time while the longitudinal pressure starts from a negative value and increases towards zero.
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.
NASA Astrophysics Data System (ADS)
Chesnaux, R.
2015-11-01
The impacts of sea-level rise due to climate change on seawater intrusion in sloping-shore coastal unconfined aquifers are investigated. The study provides four closed-form analytical solutions for: (1) assessing the change in water-table elevation of coastal aquifers resulting from sea-level rise; (2) calculating the magnitude of the change of the saltwater inland toe migration within coastal aquifers in a context of sea-level rise; (3) measuring the change of groundwater travel times through coastal aquifers in a context of sea-level rise, and (4) calculating the change in the quantity (changes of volume) of coastal fresh groundwater resources in a context of sea-level rise. The solutions apply to Dupuit-flow type conditions considering one-dimensional horizontal flow for homogenous and isotropic unconfined aquifers recharged by constant surface infiltration and discharging to the ocean, under steady-state conditions and assuming a sharp interface of the saltwater/freshwater transition zone. Examples are provided to illustrate how to apply the new solutions and conduct sensitivity analyses of the critical parameters involved in the equations. Taking into account the angle of the shore slope, these solutions constitute new analytical tools aiming to better measure the effects of land-surface inundation and anticipate changes in groundwater resources in coastal aquifers in a context of climate change.
Energy levels and radiative rates for transitions in Ti VI
NASA Astrophysics Data System (ADS)
Aggarwal, Kanti; Keenan, Francis; Msezane, Alfred Z.
2012-06-01
Energies for 568 levels among the n=3+3p^64l+3s3p^54l configurations of Ti VI are calculated using the GRASP (General-purpose Relativistic Atomic Structure Program) code, which is based on the multi-configuration Dirac-Fock (MCDF) method. Additionally, radiative rates are calculated for all types of transitions, namely electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2). Lifetimes are also calculated for all the levels and extensive comparisons are made with the earlier available data as well as with other parallel calculations from the FAC (Flexible Atomic Code). Discrepancies for several levels with the earlier calculations of Mohan et al, (ADNDT 93 105 (2007)) are highlighted.
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.
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.
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.
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.
NASA Astrophysics Data System (ADS)
Versluis, Louis; Ziegler, Tom
1988-01-01
An algorithm, based on numerical integration, has been proposed for the evaluation of analytical energy gradients within the Hartree-Fock-Slater (HFS) method. The utility of this algorithm in connection with molecular structure optimization is demonstrated by calculations on organics, main group molecules, and transition metal complexes. The structural parameters obtained from HFS calculations are in at least as good agreement with experiment as structures obtained from ab initio HF calculations. The time required to evaluate the energy gradient by numerical integration constitutes only a fraction (40%-25%) of the elapsed time in a full HFS-SCF calculation. The algorithm is also suitable for density functional methods with exchange-correlation potential different from that employed in the HFS method.
Lan, W G; Wong, M K; Chen, N; Sin, Y M
1995-04-01
The theory and methodology of a three-level orthogonal array design as a chemometric method for the optimization of analytical procedures were developed. In the theoretical section, firstly, the matrix of a three-level orthogonal array design is described and orthogonality is proved by a quadratic regression model. Next, the assignment of experiments in a three-level orthogonal array design and the use of the triangular table associated with the corresponding orthogonal array matrix are illustrated, followed by the data analysis strategy, in which significance of the different factor effects is quantitatively evaluated by the analysis of variance (ANOVA) technique and the percentage contribution method. Then, a quadratic regression equation representing the response surface is established to estimate each factor that has a significant influence. Finally, on the basis of the quadratic regression equation established, the derivative algorithm is used to find the optimum value for each variable considered. In the application section, microwave dissolution for the determination of selenium in biological samples by hydride generation atomic absorption spectrometry is employed, as a practical example, to demonstrate the application of the proposed three-level orthogonal array design in analytical chemistry. PMID:7771675
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
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.
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.
Fermi-level stabilization energy in group III nitrides
Li, S.X.; Jones, R.E.; Haller, E.E.; Yu, K.M.; Wu, J.; Walukiewicz, W.; Ager, J.W. III; Shan, W.; Lu Hai; Schaff, William J.
2005-04-15
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.
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)
Schindlmayr, Arno
2013-02-01
The GW approximation for the electronic self-energy is an important tool for the quantitative prediction of excited states in solids, but its mathematical exploration is hampered by the fact that it must, in general, be evaluated numerically even for very simple systems. In this paper I describe a nontrivial model consisting of two electrons on the surface of a sphere, interacting with the normal long-range Coulomb potential, and show that the GW self-energy, in the absence of self-consistency, can in fact be derived completely analytically in this case. The resulting expression is subsequently used to analyze the convergence of the energy gap between the highest occupied and the lowest unoccupied quasiparticle orbital with respect to the total number of states included in the spectral summations. The asymptotic formula for the truncation error obtained in this way, whose dominant contribution is proportional to the cutoff energy to the power -3/2, may be adapted to extrapolate energy gaps in other systems.
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.
NASA Astrophysics Data System (ADS)
Ooi, B. L.; Gilbert, J. M.; Aziz, A. Rashid A.
2016-05-01
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.
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.
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
2014-05-01
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. PMID:24811621
NASA Astrophysics Data System (ADS)
Delcey, Mickaël G.; Freitag, Leon; Pedersen, Thomas Bondo; Aquilante, Francesco; Lindh, Roland; González, Leticia
2014-05-01
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.
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.
Energy level alignment in Au/pentacene/PTCDA trilayer stacks
NASA Astrophysics Data System (ADS)
Sehati, P.; Braun, S.; Fahlman, M.
2013-09-01
Ultraviolet photoelectron spectroscopy is used to investigate the energy level alignment and molecular orientation at the interfaces in Au/pentacene/PTCDA trilayer stacks. We deduced a standing orientation for pentacene grown on Au while we conclude a flat lying geometry for PTCDA grown onto pentacene. We propose that the rough surface of polycrystalline Au induces the standing geometry in pentacene. It is further shown that in situ deposition of PTCDA on pentacene can influence the orientation of the surface pentacene layer, flipping part of the surface pentacene molecules into a flat lying geometry, maximizing the orbital interaction across the pentacene-PTCDA heterojunction.
NASA Astrophysics Data System (ADS)
Stübbe, Oliver
2015-03-01
Optical interconnects on printed circuit board level are a promising choice to support high bandwidth for short distance interconnects. These interconnects consists of highly multimode step index waveguides with rectangular core cross sections. Therefore ray tracing is an excellent method to determine the optical path parameters, e.g. optical power, ray path lengths and local ray directions. Based on these parameters the step response, the transient transfer function and the coupling behavior can be calculated. Classical ray tracing methods calculates the optical path parameters of each ray by successively computing internal reflections until a termination condition is reached. Therefore the computing time depends on the number of internal reflections. If the optical waveguide consists of cascaded straight and curved segments, e. g. point-to-point interconnects, one can use the analytic ray tracing method to determine the optical path parameters. The whole path parameters of each ray are determined by one analytical computation. The computing time depends on the number of segments. The analytic ray tracing method is unusable to determine ray path parameters of segments with varying core cross sections, e.g. tapers, crossings, splitters and combiners.
NASA Astrophysics Data System (ADS)
Zou, Wenli; Filatov, Michael; Cremer, Dieter
2015-06-01
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 Hg2 and Cn2, which are due to the admixture of more bonding character to the highest occupied spinors.
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.
Zou, Wenli; Filatov, Michael; Cremer, Dieter
2015-06-01
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 Hg2 and Cn2, which are due to the admixture of more bonding character to the highest occupied spinors. PMID:26049478
[An analytic method of wavelet energy value to evaluate the contraction intensity of uterus].
Yang, Jianping; Xiao, Kaixuan
2012-02-01
The data of uterine contraction pressure is the information source for extracting uterine contractions status. Because there is a variety of interference existing in contraction pressure data, commonly used methods such as uterine contraction intensity integration method can not obtain decent evaluation results. We used the bior 2.4 biorthogonal wavelet to decompose and reconstruct the pressure data in order to obtain the best denoising effect. Combining with the denoised results, we proposed an algorithm of the wavelet energy value. Based on the algorithm, we calculated the curve of wavelet energy value. It was proved that using the curve of wavelet energy value can better identify contractions waveform and evaluation contractions intensity. PMID:22404012
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)
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 Astrophysics Data System (ADS)
Martyanov, Vladimir; Kocharovsky, Vladimir; Kocharovsky, Vitaly
We present analytical description of a self-consistent stationary boundary layer formed between the magnetized and nonmagnetized collisionless plasmas with arbitrary energy distribution of particles. Various spatial profiles of the current and respective particle distributions in the neutral current sheets are found on the basis of the self-consistency equation of the Grad-Shafranov type, which takes into account a homogeneous external magnetic field. The solutions are obtained due to development of the method of invariants of particle motion (Astron. Lett. 36, 396 (2010)) and provide, for the first time, a detailed description of various transition domains in the magnetospheres of stars and planets, in particular, boundary regions formed by an interaction of a solar wind with an interstellar medium or Earth magnetosphere. We restrict ourselves to the shearless magnetic field configurations and consider four special dependencies of particle distribution function on momentum parallel to current direction, which make it possible to detail the relations between the magnetic field profile, plasma density, and particle anisotropy gradient, including both thin and thick (with respect to a particle gyroradius) layers. Special attention is paid to the cases of an utmost sharp boundary between the magnetized and nonmagnetized plasmas and to the cases where there are sections of a boundary current sheet with magnetic field energy density exceeding kinetic energy density of plasma particles. The kinetic instabilities and reconnection phenomena are also discussed, especially the ones related to the Weibel instability in the weakly magnetized parts of the boundary layer. These analytical results are applied to the analysis of the spacecraft observations of the magnetized-nonmagnetized boundaries in cosmic plasma.
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.
Zeng, Qiao; Liang, WanZhen
2015-10-01
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. PMID:26450289
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.
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
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. PMID:24910313
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.
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
Assessing regional wind energy resources with biological indicators: A decision-analytic approach
Katzman, M.T. )
1989-01-01
The nation's substantial wind-energy resources are unevenly distributed, with highly profitable sites being relatively rare. The absence of long-term wind speed makes siting of wind-energy conversion systems (WECS) extremely risky. Before investing in precise anemometry, wind prospectors may arrive at a first approximation with biological indicators, which are fairly inexpensive. This article describes an effort at calibrating three characteristics of mesquite trees at two sites in Texas, with wind speeds above and below the apparent economic threshold. These indicators differ in their cost of data acquisition. A discriminant analysis indicates the accuracy of these indicators in classifying samples. The value, risks, and cost effectiveness of biological information in assessing regional wind resources is illustrated through decision analysis.