Fine-structure energy levels, oscillator strengths and lifetimes of ...

Indian Academy of Sciences (India)

with the experimental results compiled in the NIST Data Base. Many new ... Keywords. Relativistic fine-structure levels; oscillator strengths; lifetimes. ... have calculated oscillator strengths and lifetimes using the Briet–Pauli R-Matrix ..... [2] The Opacity Project Team, The Opacity Project (Institute of Physics Publishing,. Bristol ...

High-energy band structure of gold

DEFF Research Database (Denmark)

Christensen, N. Egede

1976-01-01

The band structure of gold for energies far above the Fermi level has been calculated using the relativistic augmented-plane-wave method. The calculated f-band edge (Γ6-) lies 15.6 eV above the Fermi level is agreement with recent photoemission work. The band model is applied to interpret...

The relationship between energy consumption structure, economic structure and energy intensity in China

International Nuclear Information System (INIS)

Feng Taiwen; Sun Linyan; Zhang Ying

2009-01-01

This paper investigates the long-run equilibrium relationships, temporal dynamic relationships and causal relationships between energy consumption structure, economic structure and energy intensity in China. Time series variables over the periods from 1980 to 2006 are employed in empirical tests. Cointegration tests suggest that these three variables tend to move together in the long-run. In addition, Granger causality tests indicate that there is a unidirectional causality running from energy intensity to economic structure but not vice versa. Impulse response analysis provides reasonable evidences that one shock of the three variables will cause the periods of destabilized that followed. However, the impact of the energy consumption structure shock on energy intensity and the impact of the economic structure shock on energy consumption structure seem to be rather marginal. The findings have significant implications from the point of view of energy conservation and economic development. In order to decrease energy intensity, Chinese government must continue to reduce the proportion of coal in energy consumption, increase the utilization efficiency of coal and promote the upgrade of economic structure. Furthermore, a full analysis of factors that may relate to energy intensity (e.g. energy consumption structure, economic structure) should be conducted before making energy policies.

Hybrid Density Functional Study of the Local Structures and Energy Levels of CaAl2O4:Ce3.

Science.gov (United States)

Lou, Bibo; Jing, Weiguo; Lou, Liren; Zhang, Yongfan; Yin, Min; Duan, Chang-Kui

2018-05-03

First-principles calculations were carried out for the electronic structures of Ce 3+ in calcium aluminate phosphors, CaAl 2 O 4 , and their effects on luminescence properties. Hybrid density functional approaches were used to overcome the well-known underestimation of band gaps of conventional density functional approaches and to calculate the energy levels of Ce 3+ ions more accurately. The obtained 4f-5d excitation and emission energies show good consistency with measured values. A detailed energy diagram of all three sites is obtained, which explains qualitatively all of the luminescent phenomena. With the results of energy levels calculated by combining the hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE06) and the constraint occupancy approach, we are able to construct a configurational coordinate diagram to analyze the processes of capture of a hole or an electron and luminescence. This approach can be applied for systematic high-throughput calculations in predicting Ce 3+ activated luminescent materials with a moderate computing requirement.

Multifunctional Structures for High-Energy Lightweight Load-Bearing Storage

Science.gov (United States)

Loyselle, Patricia L.

2018-01-01

This is a pull-up banner of the Multifunctional Structures for High-Energy Lightweight Load-bearing Storage (M-SHELLS) technology that will be on display at the SciTech Conference in January 2018. Efforts in Multifunctional Structures for High Energy Load-Bearing Storage (M-Shells) are pushing the boundaries of development for hybrid electric propulsion for future commercial aeronautical transport. The M-Shells hybrid material would serve as the power/energy storage of the vehicle and provide structural integrity, freeing up usable volume and mass typically occupied by bulky batteries. The ultimate goal is to demonstrate a system-level mass savings with a multifunctional structure with energy storage.

The level structure of 114Cd

International Nuclear Information System (INIS)

Mheemeed, Ahmad.

1981-10-01

The work presented in this thesis is aimed at the investigation of the level structure of 114 Cd up to an excitation energy of 3.6 MeV. Gamma radiation following thermal neutron capture in 113 Cd in the energy region from 50 keV to 2.2 MeV has been measured by means of the three curved - crystal γ-ray spectrometers, GAMS 1 and GAMS 2/3 at the I.L.L. reactor. Furthermore internal conversion electrons have been measured with the electron spectrometer BILL installed at the I.L.L. Several targets were prepared by the evaporation or sedimentation technique in order to measure the electrons in the energy region from 40 keV to 8.5 MeV. Multipolarities for a large number of transitions were determined. Primary γ-ray following average resonance neutron capture at Esub(n)=2 keV and 24 keV were recorded at the Brookhaven National Laboratory resulting in a complete set of levels with Isup(π) +- up to 3 MeV excitation energy. Combining these results a level scheme up to 3.6 MeV has been constructed [fr

Exuberance in China's renewable energy investment: Rationality, capital structure and implications with firm level evidence

International Nuclear Information System (INIS)

Zhang, Dayong; Cao, Hong; Zou, Peijiang

2016-01-01

The new century has witnessed phenomenal worldwide growth in renewable energy investments. China has been especially remarkable, surpassing both the US and the EU in 2013. Some recent facts, however, have raised the question of whether exuberant investment in China’s renewable energy sector is rational. This paper aims to contribute to the literature and to the debate in two ways. First, it tests the over-investment hypothesis based on the main stream finance methodology; second, it analyzes the role of capital structure in the performance of China's renewable energy firms. Empirical results show that overinvestment in the renewable energy sector exists. The problem is more significant in the biomass and wind sector. Capital structure is found to be more important to downstream firms, indicating that policy makers may provide support that enables these firms to finance their investments through corporate bonds, commercial credit, or long-terms debts. - Highlights: •We test the over-investment hypothesis of renewable energy firms in China. •The role of capital structure is also empirically investigated. •We find irrational investment and confirm the role of financing structure. •The results are sensitive to the main business sectors and industrial line.

Temperature dependent energy levels of methylammonium lead iodide perovskite

Science.gov (United States)

Foley, Benjamin J.; Marlowe, Daniel L.; Sun, Keye; Saidi, Wissam A.; Scudiero, Louis; Gupta, Mool C.; Choi, Joshua J.

2015-06-01

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.

Wood-energy: success depends on the price of fossil energies and on the carbon tax level

International Nuclear Information System (INIS)

Defaye, Serge; Maindrault, Marc

2016-01-01

Illustrated by several graphs indicating the structure of fossil energy prices, the comparison between domestic fuel and wood-energy for public network exploitation, the levels of fossil prices and carbon tax for non-subsidised projects, this article analyses the development of biomass (and more particularly wood-energy), the success of which depends on the price of fossil energies and on the carbon tax level. It outlines the differences of price-building elements between fossil and renewable heat, that subsidies are necessary if reference prices are low. It discusses the influence of carbon tax level and of fossil prices. It finally identifies conditions to be met (reduction of fossil energy supply and therefore higher fossil prices, introduction of a carbon tax) to reach COP objectives

Crest Level Optimization of the Multi Level Overtopping based Wave Energy Converter Seawave Slot-Cone Generator

DEFF Research Database (Denmark)

Kofoed, Jens Peter; Osaland, E.

2005-01-01

The paper describes the optimization of the crest levels and geometrical layout of the SSG structure, focusing on maximizing the obtained potential energy in the overtopping water. During wave tank testing at AAU average overtopping rates into the individual reservoirs have been measured. The ini......The paper describes the optimization of the crest levels and geometrical layout of the SSG structure, focusing on maximizing the obtained potential energy in the overtopping water. During wave tank testing at AAU average overtopping rates into the individual reservoirs have been measured....... The initial tests led to an expression describing the derivative of the overtopping rate with respect to the vertical distance. Based on this, numerical optimizations of the crest levels, for a number of combinations of wave conditions, have been performed. The hereby found optimal crest levels have been...

Intermediate and high energy nuclear reactions at the hadronic structural level

Energy Technology Data Exchange (ETDEWEB)

Slowinski, B [Institute of Physics, Warsaw, University of Technology, Poland, Institute of Atomic Energy, Swierk, (Poland)

1997-12-31

Form tens of MeV to several hundred of GeV is stretched out quite a large interval of energy when the interaction between hadrons (for instance, pion/nucleon-nucleus and nucleus-nucleus reactions) can be described by the considerably simplified way with still acceptable accuracy. This happens because in this energy region hadrons (i.e. pions, nucleons etc.) remain quasiparticles of nuclear matter mostly without revealing any internal structure, their de Broglie`s wavelength is much shorter as compared to the average intranuclear nucleon`s distance, and the energy transfers in the reaction are, on the average, significantly greater than the binding energy of nucleons inside nuclei. Consequently an approach to the analysis of these phenomena based on simple geometric and probabilistic considerations is justifiable, especially for many practical purposes, in particular, for shielding and dosimetric estimations, material behaviour prediction, as well as for the approximate evaluation of electronuclear breeding effects in different composites of target materials, for nuclear passivation problems and so on. In this work basic physical reasons of such a simplified picture of intermediate and high energy nuclear reactions are presented. The most usual phenomenological models of hadronic multiple emission/production and recent results of the cascade evaporation type models, are also discussed. 2 figs.

Temperature dependent energy levels of methylammonium lead iodide perovskite

Energy Technology Data Exchange (ETDEWEB)

Foley, Benjamin J.; Marlowe, Daniel L.; Choi, Joshua J., E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Sun, Keye; Gupta, Mool C., E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Saidi, Wissam A. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States); Scudiero, Louis, E-mail: jjc6z@virginia.edu, E-mail: mgupta@virginia.edu, E-mail: scudiero@wsu.edu [Chemistry Department and Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164 (United States)

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.

Fine structure of V2+ energy levels in CsCaF3:V2+

International Nuclear Information System (INIS)

Avram, C.N.; Brik, M.G.

2004-01-01

Theoretical investigations of the fine structure of the lasing 4 T 2g level in a CsCaF 3 :V 2+ crystal were carried out. The spin-orbit splitting of the 4 T 2g term in the static low crystal field was obtained from the Eisenstein matrices and using parameters (Dq, B, C, ζ SO ) appropriate for the 4 T 2g - 4 A 2g zero-phonon line. The 4 T 2g spinor splitting has been modeled by the second-order spin-orbit Hamiltonian. The effect of the dynamical Jahn-Teller interaction on the spin-orbit splitting of the 4 T 2g term was taken into account; the Jahn-Teller stabilization energy, ZPL splitting and the Huang-Rhys parameter for the e g normal mode were all evaluated

Energy Harvesting for Aerospace Structural Health Monitoring Systems

International Nuclear Information System (INIS)

Pearson, M R; Eaton, M J; Pullin, R; Featherston, C A; Holford, K M

2012-01-01

Recent research into damage detection methodologies, embedded sensors, wireless data transmission and energy harvesting in aerospace environments has meant that autonomous structural health monitoring (SHM) systems are becoming a real possibility. The most promising system would utilise wireless sensor nodes that are able to make decisions on damage and communicate this wirelessly to a central base station. Although such a system shows great potential and both passive and active monitoring techniques exist for detecting damage in structures, powering such wireless sensors nodes poses a problem. Two such energy sources that could be harvested in abundance on an aircraft are vibration and thermal gradients. Piezoelectric transducers mounted to the surface of a structure can be utilised to generate power from a dynamic strain whilst thermoelectric generators (TEG) can be used to generate power from thermal gradients. This paper reports on the viability of these two energy sources for powering a wireless SHM system from vibrations ranging from 20 to 400Hz and thermal gradients up to 50°C. Investigations showed that using a single vibrational energy harvester raw power levels of up to 1mW could be generated. Further numerical modelling demonstrated that by optimising the position and orientation of the vibrational harvester greater levels of power could be achieved. However using commercial TEGs average power levels over a flight period between 5 to 30mW could be generated. Both of these energy harvesting techniques show a great potential in powering current wireless SHM systems where depending on the complexity the power requirements range from 1 to 180mW.

URBAN FEATURES AND ENERGY CONSUMPTION AT LOCAL LEVEL

Directory of Open Access Journals (Sweden)

Ali Soltani

2012-12-01

Full Text Available There has been a growing interest in discovering the human effects on the environment and energy consumption in recent decades. It is estimated that the share of energy consumed in transportation and housing systems are around 20 and 30 percent of total energy consumption respectively. Furthermore, the residential greenhouse emissions depend on urban form and structure. This paper explores the effects of urban features on residential energy consumption at neighborhood level using data collected through household questionnaire (n=140. Two residential districts in metropolitan Shiraz, south of Iran, were selected as case study areas. Different features of two areas were compared including building density, typology, housing location, parcel size, floor area and construction materials. Ordinary linear regression was used to discover the impact of explanatory variables on energy consumption. It was found that some physical variables such as parcel size, setback and number of floors played significant roles in explaining the variances exist in energy use level. The results can be used by governmental agencies to modify land use policies and subdivision rules in hope of saving energy and achieving a sustainable community.

Structural, geographic, and social factors in urban building energy use: Analysis of aggregated account-level consumption data in a megacity

International Nuclear Information System (INIS)

Porse, Erik; Derenski, Joshua; Gustafson, Hannah; Elizabeth, Zoe; Pincetl, Stephanie

2016-01-01

Residential and commercial buildings comprise approximately forty percent of total energy consumption and carbon dioxide emissions in the U.S. Yet, while California spends $1.5 billion annually on energy efficiency programs, limited research has explored how building energy consumption varies within cities, including the social and structural factors that influence electricity and natural gas use. We present results from an analysis of aggregated account-level utility billing data for energy consumption across the over two million properties in Los Angeles County. Results show that consumption in L.A. County varies widely with geography, income, building characteristics, and climate. Several higher-income areas have greater total energy use per building even in cooler climates, while many lower-income regions rank higher for energy use per square-foot. Energy consumption also correlates with building age, which varies widely throughout the region. Our results demonstrate the many complex and interrelated factors that influence urban energy use. While billing data is critical for devising energy efficiency programs that actually realize estimated savings and promote more sustainable cities, opening access to such data presents significant challenges for protecting personal privacy. The presented approach is adaptable and scalable to cities seeking to develop data-driven policies to reduce building energy use. - Highlights: •Building energy use varies widely across metropolitan Los Angeles. •Building age, household income, home ownership rates, and land use are all correlated with energy consumption. •High-income areas use more energy per building, while lower-income areas use more energy per square-foot. •Account-level energy use data can help local governments devise conservation strategies. •Energy efficiency programs need evaluated using energy consumption data.

Low-lying level structure of 73Kr

International Nuclear Information System (INIS)

Moltz, D.M.; Robertson, J.D.; Norman, E.B.; Burde, J.; Beausang, C.W.

1993-01-01

We have used the 40 Ca( 36 Ar, 2pn) reaction to study the low-lying level structure of 73 Kr. By utilizing a bombarding energy at the Coulomb barrier, the relative cross section for this channel was enhanced to a few percent of the total reaction cross section. Levels in 73 Kr were assigned based primarily upon observed neutron-gamma-gamma coincidences and upon comparisons of these newly assigned transition cross sections with those from known nuclei. (orig.)

Theoretical Study of Energy Levels and Transition Probabilities of Boron Atom

Science.gov (United States)

Tian Yi, Zhang; Neng Wu, Zheng

2009-08-01

Full Text PDF Though the electrons configuration for boron atom is simple and boron atom has long been of interest for many researchers, the theoretical studies for properties of BI are not systematic, there are only few results reported on energy levels of high excited states of boron, and transition measurements are generally restricted to transitions involving ground states and low excited states without considering fine structure effects, provided only multiplet results, values for transitions between high excited states are seldom performed. In this article, by using the scheme of the weakest bound electron potential model theory calculations for energy levels of five series are performed and with the same method we give the transition probabilities between excited states with considering fine structure effects. The comprehensive set of calculations attempted in this paper could be of some value to workers in the field because of the lack of published calculations for the BI systems. The perturbations coming from foreign perturbers are taken into account in studying the energy levels. Good agreement between our results and the accepted values taken from NIST has been obtained. We also reported some values of energy levels and transition probabilities not existing on the NIST data bases.

Spectroscopic properties and energy levels of Yb{sup 3+} ion in huntite structure

Energy Technology Data Exchange (ETDEWEB)

Malakhovskii, A.V. [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation)], E-mail: malakha@iph.krasn.ru; Sukhachev, A.L. [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Gnatchenko, S.L.; Kachur, I.S.; Piryatinskaya, V.G. [B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, 61103 Kharkov (Ukraine); Temerov, V.L.; Krylov, A.S.; Edelman, I.S. [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation)

2009-05-12

Temperature dependence of Yb{sup 3+} optical absorption spectrum has been studied in crystals Yb{sub x}Tm{sub 1-x}Al{sub 3}(BO{sub 3}){sub 4} (x = 0.1, 0.2 and 1) in the temperature range 1.7-293 K. The spectra of the crystals appeared to be practically identical for the studied ytterbium concentrations. Raman scattering spectrum of YbAl{sub 3}(BO{sub 3}){sub 4} crystal has been measured. Group theory analysis of the optical absorption spectra is made, and new energy structure of the ground and excited states of Yb{sup 3+} ion, based on the experimental data obtained, is presented. Transformation of the local environment of Yb{sup 3+} ion depending on temperature has been found out. Spectrum of luminescence has been calculated from the absorption spectrum by reciprocity method with the use of the proposed energy structure.

Level structures in 156Pm from 156Nd β - decay

International Nuclear Information System (INIS)

Sood, P.C.; Gowrishankar, R.; Sainath, M.; Singh, B.

2012-01-01

Level energies in two-quasiparticle (2qp) structures in 156 61 Pm 95 are evaluated using the phenomenological rotor-particle model for odd-odd deformed nuclei with the inclusion of the residual p-n interaction contribution. Using these results as location guides, the experimental data from a recent 156 Nd decay study are used to construct a level scheme for 156 Pm with excitation energies upto 550 keV, wherein 26 (out of 30) γ's reported in 156 Nd decay are incorporated. Spin-parities and configuration assignments are suggested for 15 levels, in addition to the two isomers, in this energy domain. These investigations point to the need for information on higher-energy γ's and on β-γ and γ-γ coincidence data from 156 Nd β-decay to confirm these assignments. (orig.)

Efficient red organic electroluminescent devices based on trivalent europium complex obtained by designing the device structure with stepwise energy levels

Energy Technology Data Exchange (ETDEWEB)

Zhou, Liang; Jiang, Yunlong; Cui, Rongzhen; Li, Yanan; Zhao, Xuesen; Deng, Ruiping; Zhang, Hongjie, E-mail: hongjie@ciac.ac.cn

2016-02-15

In this study, we aim to further enhance the electroluminescence (EL) performances of trivalent europium complex Eu(TTA){sub 3}phen (TTA=thenoyltrifluoroacetone and phen=1,10-phenanthroline) by designing the device structure with stepwise energy levels. The widely used bipolar material 2,6-bis(3-(9H-carbazol-9-yl)phenyl)pyridine (26DCzPPy) was chosen as host material, while the doping concentration of Eu(TTA){sub 3}phen was optimized to be 4%. To facilitate the injection and transport of holes, MoO{sub 3} anode modification layer and 4,4′,4′′-Tris(carbazole-9-yl)triphenylamine (TcTa) hole transport layer were inserted in sequence. Efficient pure red emission with suppressed efficiency roll-off was obtained attributed to the reduction of accumulation holes, the broadening of recombination zone, and the improved balance of holes and electrons on Eu(TTA){sub 3}phen molecules. Finally, the device with 3 nm MoO{sub 3} and 5 nm TcTa obtained the highest brightness of 3278 cd/m{sup 2}, current efficiency of 12.45 cd/A, power efficiency of 11.50 lm/W, and external quantum efficiency of 6.60%. Such a device design strategy helps to improve the EL performances of emitters with low-lying energy levels and provides a chance to simplify device fabrication processes. - Highlights: • Electroluminescent performances of europium complex were further improved. • Device structure with stepwise energy levels was designed. • Better carriers' balance was realized by improving the injection and transport of holes. • The selection of bipolar host caused the broadening of recombination zone.

Energy level alignment at Co/AlOx/pentacene interfaces

NARCIS (Netherlands)

Popinciuc, M.; Jonkman, H. T.; van Wees, B. J.

2007-01-01

X-ray and ultraviolet photoemission spectroscopy (XPS and UPS) experiments were performed in order to study the energy level alignment and electronic structure at Co/AlOx/pentacene interfaces as a function of the aluminum oxide (AlOx) tunnel barrier thickness and the oxidation state of Co. XPS was

Reliability-Based Structural Optimization of Wave Energy Converters

Directory of Open Access Journals (Sweden)

Simon Ambühl

2014-12-01

Full Text Available More and more wave energy converter (WEC concepts are reaching prototypelevel. Once the prototype level is reached, the next step in order to further decrease thelevelized cost of energy (LCOE is optimizing the overall system with a focus on structuraland maintenance (inspection costs, as well as on the harvested power from the waves.The target of a fully-developed WEC technology is not maximizing its power output,but minimizing the resulting LCOE. This paper presents a methodology to optimize thestructural design of WECs based on a reliability-based optimization problem and the intentto maximize the investor’s benefits by maximizing the difference between income (e.g., fromselling electricity and the expected expenses (e.g., structural building costs or failure costs.Furthermore, different development levels, like prototype or commercial devices, may havedifferent main objectives and will be located at different locations, as well as receive varioussubsidies. These points should be accounted for when performing structural optimizationsof WECs. An illustrative example on the gravity-based foundation of the Wavestar deviceis performed showing how structural design can be optimized taking target reliability levelsand different structural failure modes due to extreme loads into account.

Corrections to O(α7(lnα)mc2) fine-structure splittings and O(α6(lnα)mc2) energy levels in helium

International Nuclear Information System (INIS)

Zhang, T.

1996-01-01

Fully relativistic formulas for the energy-level shifts arising from no-pair exchange diagrams of two transverse photons plus an arbitrary number of Coulomb photons are derived in closed form within the external potential Bethe-Salpeter formalism. O(α 7 (lnα)mc 2 ) corrections to the fine-structure splittings of helium are obtained and expressed in terms of expectation values of nonrelativistic operators. O(α 7 mc 2 ) operators from exchange diagrams are found in nonrelativistic approximation. O(α 6 m 2 c 2 /M) nucleus-electron operators contributing to the fine-structure splittings are derived. Nonrelativistic operators of O(α 6 mc 2 ) corrections to the triplet levels of helium are presented. Nonrelativistic operators of O(α 6 (lnα)mc 2 ) corrections to the helium singlet levels and to positronium S levels are derived. O(α 6 m 2 c 2 /M) hydrogen and O(α 6 mc 2 ) positronium P levels, and O(α 6 (lnα)mc 2 ) corrections of first order to positronium S levels, are calculated using the derived operators for helium, in agreement with those obtained previously by others, except for one term in corrections to positronium P levels. In addition, the O(α 6 mc 2 ) Dirac energies for hydrogenic non-S levels are exactly reproduced in a perturbative calculation. copyright 1996 The American Physical Society

Community investment in wind farms: funding structure effects in wind energy infrastructure development.

Science.gov (United States)

Beery, Joshua A; Day, Jennifer E

2015-03-03

Wind energy development is an increasingly popular form of renewable energy infrastructure in rural areas. Communities generally perceive socioeconomic benefits accrue and that community funding structures are preferable to corporate structures, yet lack supporting quantitative data to inform energy policy. This study uses the Everpower wind development, to be located in Midwestern Ohio, as a hypothetical modeling environment to identify and examine socioeconomic impact trends arising from corporate, community and diversified funding structures. Analysis of five National Renewable Energy Laboratory Jobs and Economic Development Impact models incorporating local economic data and review of relevant literature were conducted. The findings suggest that community and diversified funding structures exhibit 40-100% higher socioeconomic impact levels than corporate structures. Prioritization of funding sources and retention of federal tax incentives were identified as key elements. The incorporation of local shares was found to mitigate the negative effects of foreign private equity, local debt financing increased economic output and opportunities for private equity investment were identified. The results provide the groundwork for energy policies focused to maximize socioeconomic impacts while creating opportunities for inclusive economic participation and improved social acceptance levels fundamental to the deployment of renewable energy technology.

Structure model of energy efficiency indicators and applications

International Nuclear Information System (INIS)

Wu, Li-Ming; Chen, Bai-Sheng; Bor, Yun-Chang; Wu, Yin-Chin

2007-01-01

For the purposes of energy conservation and environmental protection, the government of Taiwan has instigated long-term policies to continuously encourage and assist industry in improving the efficiency of energy utilization. While multiple actions have led to practical energy saving to a limited extent, no strong evidence of improvement in energy efficiency was observed from the energy efficiency indicators (EEI) system, according to the annual national energy statistics and survey. A structural analysis of EEI is needed in order to understand the role that energy efficiency plays in the EEI system. This work uses the Taylor series expansion to develop a structure model for EEI at the level of the process sector of industry. The model is developed on the premise that the design parameters of the process are used in comparison with the operational parameters for energy differences. The utilization index of production capability and the variation index of energy utilization are formulated in the model to describe the differences between EEIs. Both qualitative and quantitative methods for the analysis of energy efficiency and energy savings are derived from the model. Through structural analysis, the model showed that, while the performance of EEI is proportional to the process utilization index of production capability, it is possible that energy may develop in a direction opposite to that of EEI. This helps to explain, at least in part, the inconsistency between EEI and energy savings. An energy-intensive steel plant in Taiwan was selected to show the application of the model. The energy utilization efficiency of the plant was evaluated and the amount of energy that had been saved or over-used in the production process was estimated. Some insights gained from the model outcomes are helpful to further enhance energy efficiency in the plant

Energy level alignment symmetry at Co/pentacene/Co interfaces

NARCIS (Netherlands)

Popinciuc, M.; Jonkman, H. T.; van Wees, B. J.

2006-01-01

We have employed x-ray and ultraviolet photoemission spectroscopies (XPS and UPS) to study the energy level alignment and electronic structure at the Co/pentacene/Co interfaces. In the case of pentacene deposition on Co we found an interfacial dipole of about 1.05 eV and a hole injection barrier of

Comprehensive Wavelengths, Energy Levels, and Hyperfine Structure Parameters of Singly-Ionized Iron-Group Elements

Science.gov (United States)

Nave, Gillian

We propose to measure wavelengths, energy levels, and hyperfine structure parameters of Ni II, Mn II, Sc II and other singly-ionized iron-group elements, covering the wavelength range 80 nm to 5500 nm. We shall use archival data from spectrometers at NIST and Kitt Peak National Observatory for spectra above 140 nm. Additional experimental observations will be taken if needed using Fourier transform spectrometers at NIST. Spectra will be taken using our normal incidence grating spectrograph to provide better sensitivity than the FT spectra and to extend the wavelength range down to 80 nm. We aim to produce a comprehensive description of the spectra of all singly-ionized iron- group elements. The wavelength uncertainty of the strong lines will be better than 1 part in 10^7. For most singly-ionized iron-group elements available laboratory data have uncertainties an order of magnitude larger than astronomical observations over wide spectra ranges. Some of these laboratory measurements date back to the 1960's. Since then, Fourier transform spectroscopy has made significant progress in improving the accuracy and quantity of data in the UV-vis-IR region, but high quality Fourier transform spectra are still needed for Mn II, Ni II and Sc II. Fourier transform spectroscopy has low sensitivity in the VUV region and is limited to wavelengths above 140 nm. Spectra measured with high-resolution grating spectrographs are needed in this region in order to obtain laboratory data of comparable quality to the STIS and COS spectrographs on the Hubble Space Telescope. Currently, such data exist only for Fe II and Cr II. Lines of Sc II, V II, and Mn II show hyperfine structure, but hyperfine structure parameters have been measured for relatively few lines of these elements. Significant errors can occur if hyperfine structure is neglected when abundances are determined from stellar spectra. Measurements of hyperfine structure parameters will be made using Fourier transform spectroscopy

Suppressing recombination in polymer photovoltaic devices via energy-level cascades.

Science.gov (United States)

Tan, Zhi-Kuang; Johnson, Kerr; Vaynzof, Yana; Bakulin, Artem A; Chua, Lay-Lay; Ho, Peter K H; Friend, Richard H

2013-08-14

An energy cascading structure is designed in a polymer photovoltaic device to suppress recombination and improve quantum yields. By the insertion of a thin polymer interlayer with intermediate energy levels, electrons and holes can effectively shuttle away from each other while being spatially separated from recombination. An increase in open-circuit voltage and short-circuit current are observed in modified devices. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Energy-level alignment at metal-organic and organic-organic interfaces

NARCIS (Netherlands)

Veenstra, Sjoerd; Jonkman, H.T.

2003-01-01

This article reports on the electronic structure at interfaces found in organic semiconductor devices. The studied organic materials are C-60 and poly (para-phenylenevinylene) (PPV)-like oligomers, and the metals are polycrystalline Au and Ag. To measure the energy levels at these interfaces,

Energy Level Alignment at Aqueous GaN and ZnO Interfaces

Science.gov (United States)

Hybertsen, Mark S.; Kharche, Neerav; Muckerman, James T.

2014-03-01

Electronic energy level alignment at semiconductor-electrolyte interfaces is fundamental to electrochemical activity. Motivated in particular by the search for new materials that can be more efficient for photocatalysis, we develop a first principles method to calculate this alignment at aqueous interfaces and demonstrate it for the specific case of non-polar GaN and ZnO interfaces with water. In the first step, density functional theory (DFT) based molecular dynamics is used to sample the physical interface structure and to evaluate the electrostatic potential step at the interface. In the second step, the GW approach is used to evaluate the reference electronic energy level separately in the bulk semiconductor (valence band edge energy) and in bulk water (the 1b1 energy level), relative to the internal electrostatic energy reference. Use of the GW approach naturally corrects for errors inherent in the use of Kohn-Sham energy eigenvalues to approximate the electronic excitation energies in each material. With this predicted interface alignment, specific redox levels in water, with potentials known relative to the 1b1 level, can then be compared to the semiconductor band edge positions. Our results will be discussed in the context of experiments in which photoexcited GaN and ZnO drive the hydrogen evolution reaction. Research carried out at Brookhaven National Laboratory under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

PC operated acoustic transient spectroscopy of deep levels in MIS structures

International Nuclear Information System (INIS)

Bury, P.; Jamnicky, I.

1996-01-01

A new version of acoustic deep-level transient spectroscopy is presented to study the traps at the insulator-semiconductor interface. The acoustic deep-level transient spectroscopy uses an acoustoelectric response signal produced by the MIS structure interface when a longitudinal acoustic wave propagates through a structure. The acoustoelectric response signal is extremely sensitive to external conditions of the structure and reflects any changes in the charge distribution, connected also with charged traps. In comparison with previous version of acoustic deep-level transient spectroscopy that closely coincides with the principle of the original deep-level transient spectroscopy technique, the present technique is based on the computer-evaluated isothermal transients and represents an improved, more efficient and time saving technique. Many tests on the software used for calculation as well as on experimental setup have been performed. The improved acoustic deep-level transient spectroscopy method has been applied for the Si(p) MIS structures. The deep-level parameters as activation energy and capture cross-section have been determined. (authors)

Atomic energy levels and Grotrian diagrams

CERN Document Server

Bashkin, Stanley

1975-01-01

Atomic Energy Levels and Grotrian Diagrams, Volume I: Hydrogen I - Phosphorus XV presents diagrams of various elements that show their energy level and electronic transitions. The book covers the first 15 elements according to their atomic number. The text will be of great use to researchers and practitioners of fields such as astrophysics that requires pictorial representation of the energy levels and electronic transitions of elements.

Superlattice band structure: New and simple energy quantification condition

Energy Technology Data Exchange (ETDEWEB)

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

2014-10-01

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

Discovery of new Praseodymium I energy levels with help of green laser light

Energy Technology Data Exchange (ETDEWEB)

Khan, Shamim; Siddiqui, Imran; Tanweer Iqbal, Syed; Windholz, Laurentius [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A 8010 Graz (Austria)

2012-07-01

The hyperfine structure (hfs) of Praseodymium I spectral lines were experimentally investigated using LIF technique in a hollow cathode discharge lamp. We report here the investigation of 100 spectral lines which resulted in a discovery of 20 new energy levels of even and odd parity. The excitation source is a tunable ring-dye laser system, operated with Coumarin 102. The laser wavelength is tuned to a strong hyperfine component of the investigated spectral line, and fluorescence signals from excited levels are searched. The hfs of the investigated line is recorded by scanning the laser frequency across the investigated region. Magnetic hf interaction constant ''A'' and angular momentum ''J'' of the combining lower and upper levels involved in the formation of the line are evaluated. If one of the combining levels is not known (in most cases upper level), the determined angular momentum ''J'' and hyperfine constant ''A'' are used to identify one of the involved levels (in most cases the lower level) and the energy of the unknown level is determined by using center of mass wave number of line and the energy of the identified level. The level found in this way must explain most of the observed fluorescence wavelengths and the hyperfine structure of the fluorescence lines appearing in FT spectrum.

Is there an optimum level for renewable energy?

International Nuclear Information System (INIS)

Moriarty, Patrick; Honnery, Damon

2011-01-01

Because continued heavy use of fossil fuel will lead to both global climate change and resource depletion of easily accessible fuels, many researchers advocate a rapid transition to renewable energy (RE) sources. In this paper we examine whether RE can provide anywhere near the levels of primary energy forecast by various official organisations in a business-as-usual world. We find that the energy costs of energy will rise in a non-linear manner as total annual primary RE output increases. In addition, increasing levels of RE will lead to increasing levels of ecosystem maintenance energy costs per unit of primary energy output. The result is that there is an optimum level of primary energy output, in the sense that the sustainable level of energy available to the economy is maximised at that level. We further argue that this optimum occurs at levels well below the energy consumption forecasts for a few decades hence. - Highlights: → We need to shift to renewable energy for climate change and fuel depletion reasons. → We examine whether renewable energy can provide the primary energy levels forecast. → The energy costs of energy rise non-linearly with renewable energy output. → There is thus an optimum level of primary energy output. → This optimum occurs at levels well below future official energy use forecasts.

Regional level approach for increasing energy efficiency

International Nuclear Information System (INIS)

Viholainen, Juha; Luoranen, Mika; Väisänen, Sanni; Niskanen, Antti; Horttanainen, Mika; Soukka, Risto

2016-01-01

Highlights: • Comprehensive snapshot of regional energy system for decision makers. • Connecting regional sustainability targets and energy planning. • Involving local players in energy planning. - Abstract: Actions for increasing the renewable share in the energy supply and improving both production and end-use energy efficiency are often built into the regional level sustainability targets. Because of this, many local stakeholders such as local governments, energy producers and distributors, industry, and public and private sector operators require information on the current state and development aspects of the regional energy efficiency. The drawback is that an overall view on the focal energy system operators, their energy interests, and future energy service needs in the region is often not available for the stakeholders. To support the local energy planning and management of the regional energy services, an approach for increasing the regional energy efficiency is being introduced. The presented approach can be seen as a solid framework for gathering the required data for energy efficiency analysis and also evaluating the energy system development, planned improvement actions, and the required energy services at the region. This study defines the theoretical structure of the energy efficiency approach and the required steps for revealing such energy system improvement actions that support the regional energy plan. To demonstrate the use of the approach, a case study of a Finnish small-town of Lohja is presented. In the case example, possible actions linked to the regional energy targets were evaluated with energy efficiency analysis. The results of the case example are system specific, but the conducted study can be seen as a justified example of generating easily attainable and transparent information on the impacts of different improvement actions on the regional energy system.

Ioniclike energy structure of neutral core-excited states in free Kr clusters

International Nuclear Information System (INIS)

Peredkov, S.; Sorensen, S.L.; Kivimaeki, A.; Schulz, J.; Maartensson, N.; Oehrwall, G.; Lundwall, M.; Rander, T.; Lindblad, A.; Bergersen, H.; Svensson, S.; Bjoerneholm, O.; Tchaplyguine, M.

2005-01-01

The development of electronic states in krypton clusters is investigated by high-resolution core-level electron spectroscopy. The energy ordering of bulk versus surface 3d -1 np(n>5) core-excited states in neutral clusters is demonstrated to be reversed to the 3d -1 5p level situation. The cluster 3d -1 6p,7p states are proven to be at a lower energy than the corresponding atomic levels. These findings reveal the ioniclike energy structure of the neutral cluster core-excited levels. The phenomenon is explained by a spatial spread of the excited orbitals over the cluster lattice

Regional energy rebound effect: The impact of economy-wide and sector level energy efficiency improvement in Georgia, USA

International Nuclear Information System (INIS)

Yu, Xuewei; Moreno-Cruz, Juan; Crittenden, John C.

2015-01-01

Rebound effect is defined as the lost part of ceteris paribus energy savings from improvements on energy efficiency. In this paper, we investigate economy-wide energy rebound effects by developing a computable general equilibrium (CGE) model for Georgia, USA. The model adopts a highly disaggregated sector profile and highlights the substitution possibilities between different energy sources in the production structure. These two features allow us to better characterize the change in energy use in face of an efficiency shock, and to explore in detail how a sector-level shock propagates throughout the economic structure to generate aggregate impacts. We find that with economy-wide energy efficiency improvement on the production side, economy-wide rebound is moderate. Energy price levels fall very slightly, yet sectors respond to these changing prices quite differently in terms of local production and demand. Energy efficiency improvements in particular sectors (epicenters) induce quite different economy-wide impacts. In general, we expect large rebound if the epicenter sector is an energy production sector, a direct upstream/downstream sector of energy production sectors, a transportation sector or a sector with high production elasticity. Our analysis offers valuable insights for policy makers aiming to achieve energy conservation through increasing energy efficiency. - Highlights: • We developed a CGE model to investigate economy-wide energy rebound in Georgia, USA. • The CGE model has detailed treatment for different energy inputs for production. • The model has a highly disaggregated sector profile helpful for policy making. • We compared the economy-wide impact shocks in different epicenter sectors. • We analyzed why epicenters generate dramatically different economy-wide impacts.

Energy structure of fullerenes and carbon nanotubes

International Nuclear Information System (INIS)

Byszewski, P.; Kowalska, E.

1997-01-01

The absorption spectrum of C 60 can be reasonably well reproduced theoretically with the use of the quantum chemistry calculation methods. It allows investigation of the influence of a deformation of C 60 on the absorption spectrum. The deformation of the electronic density on C 60 can occur under the influence of molecules of good solvent. Similar calculations of the energetic structure of carbon nanotubes does not support the idea that their chirality may strongly influence the energy levels distribution, in particular that it may open the energy gap of nanotubes. (author). 40 refs, 13 figs, 1 tab

Ideas on a competitive structure for German energy supplies

Energy Technology Data Exchange (ETDEWEB)

Bennigsen-Foerder, R v

1985-12-20

The author expresses the future need for action on the part of energy policy at Federal level in no uncertain terms. Regional experiments in energy policy and state-induced limits on competition in the heat market have documented the fact that watchfulness is to be recommended even in a relatively relaxed energy market. The author does admit that the level of electricity prices in the Federal Republic is comparatively high; overall, however, energy prices are in line with the world market situation. This can only be explained by deliberate renunciation of extensive state control of the primary energy structure. The competitiveness of German energy supplies can thus be closely linked up to the question as to what strategy will be pursued with regard to preparations for 'crisis contingency X', i.e. for another sudden explosion of energy costs. The author supports the thesis 'that it is more expensive from the point of view of the economy as a whole to prepare ex-ante for 'Day X' than it is to adapt to it ex-post'.

Preliminary findings radon daughter levels in structures constructed on reclaimed Florida phosphate land

International Nuclear Information System (INIS)

1975-09-01

Preliminary results are reported from a survey of the radon daughter levels in structures in Polk County, Florida, built on reclaimed phosphate tailings containing various amounts of 226 Ra. The structures surveyed consisted primarily of private dwellings although a few office buildings were also surveyed. Track-etch films and TLD air samplers were used to measure the levels of radon daughters within the structures and in structures built on non-phosphate land. Radiation levels were converted to WL units (the working level (WL) unit is defined as the potential α energy from the short-lived daughters of Rn which will produce 1.3 x 10 5 MeV in one liter of air). The highest observed level in any structure was 0.2 WL. Possible health hazards to long-time occupants are discussed

Energy taxes, trends and structure in OECD countries

International Nuclear Information System (INIS)

2000-01-01

Most forms of energy are taxed in industrialised countries, but taxes vary amongst regions and between products. Oil taxes are by far the most important. They accounted in 1999 for 45 per cent of the total value of the oil barrel in the market. Natural gas is taxed much less than oil, but taxes are increasing, whereas coal taxes are absent or remain negligible. Environmental considerations have resulted in higher energy taxes in some countries ? the best examples in recent years are Germany and the UK. However, treasury revenue is still the most important determinant both for the level and for the structure of energy taxes. (author)

The national energy monitoring center (OEN) - a new structure for the prognosis of the energy sector development

International Nuclear Information System (INIS)

Budulan, P.; Rugina, V.; Izsak, D.; Bogzianu, R.

2002-01-01

OEN is a new structure for the permanent assessment of energy performances by means of a complex system of indicators and methodologies, corresponding to the ones existing at the international and European levels. The OEN database contributes to the prognosis of the energy system development enabling a sustainable and competitive utilisation of natural resources. The energy sector prognosis is developed on the basis of energy balances data, energy indicators and potential of the renewable energy sources. The paper presents the actual stage of OEN development and its role in the restructuring and liberalisation of the energy sector. (author)

Energy density and rate limitations in structural composite supercapacitors

Science.gov (United States)

Snyder, J. F.; Gienger, E.; Wetzel, E. D.; Xu, K.

2012-06-01

The weight and volume of conventional energy storage technologies greatly limits their performance in mobile platforms. Traditional research efforts target improvements in energy density to reduce device size and mass. Enabling a device to perform additional functions, such as bearing mechanical load, is an alternative approach as long as the total mass efficiency exceeds that of the individual materials it replaces. Our research focuses on structural composites that function as batteries and supercapacitors. These multifunctional devices could be used to replace conventional structural components, such as vehicle frame elements, to provide significant system-level weight reductions and extend mission times. Our approach is to design structural properties directly into the electrolyte and electrode materials. Solid polymer electrolyte materials bind the system and transfer load to the fibers while conducting ions between the electrodes. Carbon fiber electrodes provide a route towards optimizing both energy storage and load-bearing capabilities, and may also obviate the need for a separate current collector. The components are being integrated using scalable, cost-effective composite processing techniques that are amenable to complex part shapes. Practical considerations of energy density and rate behavior are described here as they relate to materials used. Our results highlight the viability as well as the challenges of this multifunctional approach towards energy storage.

Energy levels and radiative rates for transitions in Ti VI

International Nuclear Information System (INIS)

Aggarwal, K M; Keenan, F P; Msezane, A Z

2013-01-01

We report on calculations of energy levels, radiative rates, oscillator strengths and line strengths for transitions among the lowest 253 levels of the (1s 2 2s 2 2p 6 ) 3s 2 3p 5 , 3s3p 6 , 3s 2 3p 4 3d, 3s3p 5 3d, 3s 2 3p 3 3d 2 , 3s 2 3p 4 4s, 3s 2 3p 4 4p and 3s 2 3p 4 4d configurations of Ti VI. The general-purpose relativistic atomic structure package and flexible atomic code are adopted for the calculations. Radiative rates, oscillator strengths and line strengths are reported for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions among the 253 levels, although calculations have been performed for a much larger number of levels. Comparisons are made with existing available results and the accuracy of the data is assessed. Additionally, lifetimes for all 253 levels are listed, although comparisons with other theoretical results are limited to only 88 levels. Our energy levels are estimated to be accurate to better than 1% (within 0.03 Ryd), whereas results for other parameters are probably accurate to better than 20%. A reassessment of the energy level data on the National Institute of Standards and Technology website for Ti VI is suggested. (paper)

Energy levels and radiative transition rates for Ge XXXI, As XXXII, and Se XXXIII

Science.gov (United States)

Aggarwal, Sunny; Singh, J.; Jha, A. K. S.; Mohan, Man

2014-07-01

Fine-structure energies of the 67 levels belonging to the 1s2, 1s 2l, 1s3l, 1s4l, 1s5l, and 1s6l configurations of Ge XXXI, As XXXII, and Se XXXIII have been calculated using the General-Purpose Relativistic Atomic Structure Package. In addition, radiative rates, oscillator strengths, transition wavelengths, and line strengths have been calculated for all electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions among these levels. Lifetimes are also presented for all excited levels of these three ions. We have compared our results with the results available in the literature and the accuracy of the data is assessed. We predict new energy levels, oscillator strengths, and transition probabilities where no other theoretical or experimental results are available, which will form the basis for future experimental work.

Energy levels of 56Mn

DEFF Research Database (Denmark)

Van Assche, P. H. M.; Baader, H. A.; Koch, H. R.

1971-01-01

The low-energy spectrum of the 55Mn(n,γ)56 Mn reaction has been studied with a γ-diffraction spectrometer. These data allowed the construction of a level scheme for 56Mn with two previously unobserved doublets. High-energy γ-transitions to the low-energy states have been measured for different...

Level structures of neutron-rich Xe isotopes

Energy Technology Data Exchange (ETDEWEB)

Ahmad, I.; Lister, C.J.; Morss, L.R. [and others

1995-08-01

The level structures of neutron-rich Xe isotopes were determined by observing prompt gamma-ray coincidences in {sup 248}Cm fission fragments. A 5-mg {sup 248}Cm, in the form of {sup 248}Cm-KCl pellet, was placed inside Eurogam array which consisted of 45 Compton-suppressed Ge detectors and 5 Low-Energy Photon Spectrometers. Transitions in Xe isotopes were identified by the appearance of new peaks in the {gamma}-ray spectra obtained by gating on the gamma peaks of the complementary Mo fragments.

Spatial-structural interaction and strain energy structural optimisation

NARCIS (Netherlands)

Hofmeyer, H.; Davila Delgado, J.M.; Borrmann, A.; Geyer, P.; Rafiq, Y.; Wilde, de P.

2012-01-01

A research engine iteratively transforms spatial designs into structural designs and vice versa. Furthermore, spatial and structural designs are optimised. It is suggested to optimise a structural design by evaluating the strain energy of its elements and by then removing, adding, or changing the

Precision Measurement of the Rovibrational Energy-Level Structure of ^{4}He^{+}_{2}

Science.gov (United States)

Semeria, Luca; Jansen, Paul; Agner, Josef A.; Schmutz, Hansjürg; Merkt, Frederic

2017-06-01

He_{2}^{+} is a three-electron system for which highly accurate ab initio calculations are possible. The latest calculations of the rovibrational energies of He_{2}^{+} by Tung et al. have a reported accuracy of 120 MHz, although they do not include relativistic and quantum electrodynamics (QED) effects. We determined the rovibrational structure of ^{4}He^{+}_{2} from measurements of the Rydberg spectrum of metastable a ^3Σ_u^+ He_{2} (He^{*}_{2} hereafter) and Rydberg-series extrapolation using multichannel quantum-defect-theory. He^{*}_{2} molecules are produced in supersonic beams with velocities tunable down to about 100 m/s by combining a cryogenic supersonic-beam source with a multistage Zeeman decelerator. They are then excited to high-np Rydberg states by single-photon excitation. In the experiments, we use a pulsed uv laser system, with a near Fourier-transform-limited bandwidth of 150 MHz. The Zeeman deceleration reduces the systematic uncertainty arising from a possible Doppler shift and greatly simplifies the spectral assignment because of its spin-rotational state selectivity. Results will be presented on the rotational structure of the lowest three vibrational levels of He^{+}_{2}. The unprecedented accuracy that we have obtained for the v^{+}=0 rotational intervals of He_{2}^{+} enables the quantification of the relativistic and QED corrections by comparison with the results of Tung et al.^a W.-C. Tung, M. Pavanello and L. Adamowicz, J. Chem. Phys., 136, 104309, 2012. C. Jungen, Elements of Quantum Defect Theory, in : Handbook of High-resolution Spectroscopy, 2001. D. Sprecher, J. Liu, T. Krähenmann, M. Schäfer, and F. Merkt, J. Chem. Phys., 140, 064304, 2014. A. W. Wiederkehr, S. D. Hogan, M. Andrist, H. Schmutz, B. Lambillotte, J. A. Agner, and F. Merkt., J. Chem. Phys., 135, 214202, 2011. M. Motsch, P. Jansen, J. A. Agner, H. Schmutz, and F. Merkt, Phys. Rev. A, 89, 043420, 2014. P. Jansen, L. Semeria, L. E. Hofer, S. Scheidegger, J. A. Agner

Holography and coherent diffraction with low-energy electrons: A route towards structural biology at the single molecule level.

Science.gov (United States)

Latychevskaia, Tatiana; Longchamp, Jean-Nicolas; Escher, Conrad; Fink, Hans-Werner

2015-12-01

The current state of the art in structural biology is led by NMR, X-ray crystallography and TEM investigations. These powerful tools however all rely on averaging over a large ensemble of molecules. Here, we present an alternative concept aiming at structural analysis at the single molecule level. We show that by combining electron holography and coherent diffraction imaging estimations concerning the phase of the scattered wave become needless as the phase information is extracted from the data directly and unambiguously. Performed with low-energy electrons the resolution of this lens-less microscope is just limited by the De Broglie wavelength of the electron wave and the numerical aperture, given by detector geometry. In imaging freestanding graphene, a resolution of 2Å has been achieved revealing the 660.000 unit cells of the graphene sheet from a single data set. Once applied to individual biomolecules the method shall ultimately allow for non-destructive imaging and imports the potential to distinguish between different conformations of proteins with atomic resolution. Copyright © 2015. Published by Elsevier B.V.

Bibliography on atomic energy levels and spectra. Special pub., Jul 1971--Jun 1975

International Nuclear Information System (INIS)

Hagan, L.

1977-01-01

This is the first supplement to the NBS Special Publication 363, 'Bibliography on Atomic Energy Levels and Spectra, July 1968 through June 1971,' and it covers the most recent literature from July 1971 through June 1975. It contains approximately 2150 references classified by subject for individual atoms and atomic ions. A number index identifies the references. An author index is included. References included contain data on energy levels, classified lines, wavelengths, Zeeman effect, Stark effect, hyperfine structure, isotope shift, ionization potentials, or theory which gives results for specific atoms or atomic ions

State-level benefits of energy efficiency

International Nuclear Information System (INIS)

Tonn, Bruce; Peretz, Jean H.

2007-01-01

This paper 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% and 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%. 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 efficiency programs are cost-effective; typical benefit-cost ratios exceed 3:1 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. (author)

State-Level Benefits of Energy Efficiency

Energy Technology Data Exchange (ETDEWEB)

Tonn, Bruce Edward [ORNL

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.

Direct characterization of the energy level alignments and molecular components in an organic hetero-junction by integrated photoemission spectroscopy and reflection electron energy loss spectroscopy analysis.

Science.gov (United States)

Yun, Dong-Jin; Shin, Weon-Ho; Bulliard, Xavier; Park, Jong Hwan; Kim, Seyun; Chung, Jae Gwan; Kim, Yongsu; Heo, Sung; Kim, Seong Heon

2016-08-26

A novel, direct method for the characterization of the energy level alignments at bulk-heterojunction (BHJ)/electrode interfaces on the basis of electronic spectroscopy measurements is proposed. The home-made in situ photoemission system is used to perform x-ray/ultraviolet photoemission spectroscopy (XPS/UPS), reflection electron energy loss spectroscopy (REELS) and inverse photoemission spectroscopy of organic-semiconductors (OSCs) deposited onto a Au substrate. Through this analysis system, we are able to obtain the electronic structures of a boron subphthalocyanine chloride:fullerene (SubPC:C60) BHJ and those of the separate OSC/electrode structures (SubPC/Au and C60/Au). Morphology and chemical composition analyses confirm that the original SubPC and C60 electronic structures remain unchanged in the electrodes prepared. Using this technique, we ascertain that the position and area of the nearest peak to the Fermi energy (EF = 0 eV) in the UPS (REELS) spectra of SubPC:C60 BHJ provide information on the highest occupied molecular orbital level (optical band gap) and combination ratio of the materials, respectively. Thus, extracting the adjusted spectrum from the corresponding SubPC:C60 BHJ UPS (REELS) spectrum reveals its electronic structure, equivalent to that of the C60 materials. This novel analytical approach allows complete energy-level determination for each combination ratio by separating its electronic structure information from the BHJ spectrum.

Refined energetic ordering for sulphate-water (n = 3-6) clusters using high-level electronic structure calculations

Science.gov (United States)

Lambrecht, Daniel S.; McCaslin, Laura; Xantheas, Sotiris S.; Epifanovsky, Evgeny; Head-Gordon, Martin

2012-10-01

This work reports refinements of the energetic ordering of the known low-energy structures of sulphate-water clusters ? (n = 3-6) using high-level electronic structure methods. Coupled cluster singles and doubles with perturbative triples (CCSD(T)) is used in combination with an estimate of basis set effects up to the complete basis set limit using second-order Møller-Plesset theory. Harmonic zero-point energy (ZPE), included at the B3LYP/6-311 + + G(3df,3pd) level, was found to have a significant effect on the energetic ordering. In fact, we show that the energetic ordering is a result of a delicate balance between the electronic and vibrational energies. Limitations of the ZPE calculations, both due to electronic structure errors, and use of the harmonic approximation, probably constitute the largest remaining errors. Due to the often small energy differences between cluster isomers, and the significant role of ZPE, deuteration can alter the relative energies of low-lying structures, and, when it is applied in conjunction with calculated harmonic ZPEs, even alters the global minimum for n = 5. Experiments on deuterated clusters, as well as more sophisticated vibrational calculations, may therefore be quite interesting.

Energy intensity developments in 40 major economies: Structural change or technology improvement?

International Nuclear Information System (INIS)

Voigt, Sebastian; De Cian, Enrica; Schymura, Michael; Verdolini, Elena

2014-01-01

This study analyzes energy intensity trends and drivers in 40 major economies using the WIOD database, a novel harmonized and consistent dataset of input–output table time series accompanied by environmental satellite data. We use logarithmic mean Divisia index decomposition to (1) attribute efficiency changes to either changes in technology or changes in the structure of the economy, (2) study trends in global energy intensity between 1995 and 2007, and (3) highlight sectoral and regional differences. For the country analysis we apply the traditional two factor index decomposition approach, while for the global analysis we use a three factor decomposition which includes the consideration of regional structural changes in the global economy. We first show that heterogeneity within each sector across countries is high. These general trends within sectors are dominated by large economies, first and foremost the United States. In most cases, heterogeneity is lower within each country across the different sectors. Regarding changes of energy intensity at the country level, improvements between 1995 and 2007 are largely attributable to technological change while structural change is less important in most countries. Notable exceptions are Japan, the United States, Australia, Taiwan, Mexico and Brazil where a change in the industry mix was the main driver behind the observed energy intensity reduction. At the global level we find that despite a shift of the global economy to more energy-intensive countries, aggregate energy efficiency improved mostly due to technological change

Energy levels, radiative rates, and lifetimes for transitions in W XL

International Nuclear Information System (INIS)

Aggarwal, Kanti M.; Keenan, Francis P.

2014-01-01

Energy levels and radiative rates are reported for transitions in Br-like tungsten, W XL, calculated with the general-purpose relativistic atomic structure package (GRASP). Configuration interaction (CI) has been included among 46 configurations (generating 4215 levels) over a wide energy range up to 213 Ryd. However, for conciseness results are only listed for the lowest 360 levels (with energies up to ∼43 Ryd), which mainly belong to the 4s 2 4p 5 ,4s 2 4p 4 4d,4s 2 4p 4 4f,4s4p 6 ,4p 6 4d,4s4p 5 4d,4s 2 4p 3 4d 2 , and 4s 2 4p 3 4d4f configurations, and provided for four types of transitions, E1, E2, M1, and M2. Comparisons are made with existing (but limited) results. However, to fully assess the accuracy of our data, analogous calculations have been performed with the flexible atomic code, including an even larger CI than in GRASP. Our energy levels are estimated to be accurate to better than 0.02 Ryd, whereas results for radiative rates (and lifetimes) should be accurate to better than 20% for a majority of the strong transitions

Development of the relaxation-assisted 2DIR method for accessing structures of molecules and its application for studying the energy transport on a molecular level

Science.gov (United States)

Kasyanenko, Valeriy Mitrofanovich

Measuring the three-dimensional structure of molecules, dynamics of structural changes, and energy transport on a molecular scale is important for many areas of natural science. Supplementing the widely used methods of x-ray diffraction, NMR, and optical spectroscopies, a two-dimensional infrared spectroscopy (2DIR) method was introduced about a decade ago. The 2DIR method measures pair-wise interactions between vibrational modes in molecules, thus acquiring molecular structural constraints such as distances between vibrating groups and the angles between their transition dipoles. The 2DIR method has been applied to a variety of molecular systems but in studying larger molecules such as proteins and peptides the method is facing challenges associated with the congestion of their vibrational spectra and delocalized character of their vibrational modes. To help extract structural information from such spectra and make efficient use of vibrational modes separated by large distances, a novel relaxation-assisted 2DIR method (RA 2DIR) has recently been proposed, which exploits the transport of excess vibrational energy from the initially excited mode. With the goal of further development of RA 2DIR, we applied it to a variety of molecular systems, including model compounds, transition-metal complexes, and isomers. The experiments revealed several novel effects which both enhance the power of RA 2DIR and bring a deeper understanding to the fundamental process of energy transport on a molecular level. We demonstrated that RA 2DIR can enhance greatly (27-fold) the cross-peak amplitude among spatially remote modes, which leads to an increase of the range of distances accessible for structural measurements by several fold. We demonstrated that the energy transport time correlates with the intermode distance. This correlation offers a new way for identifying connectivity patterns in molecules. We developed two models of energy transport in molecules. In one, a spatial overlap

Structural breaks and energy efficiency in Fiji

International Nuclear Information System (INIS)

Bhaskara Rao, B.; Rao, Gyaneshwar

2009-01-01

This paper examines how energy-output ratios (EYRs) in Fiji have responded to the major energy crises and in particular if these ratios have declined after the energy shocks. The expectation is that energy efficiency should improve after an energy crisis. For this purpose we have used at first a few simpler procedures and then a recently developed more powerful tests for structural breaks by Bai and Perron [Bai, J., Perron, P., 1998. Estimating and testing linear models with multiple structural changes. Econometrica 66, 47-78; Bai, J., Perron, P., 2003a. Computation and analysis of multiple structural change models. Journal of Applied Econometrics 18, 1-22; Bai, J., Perron, P., 2003b. Critical values for multiple structural change tests. Econometrics Journal 6, 72-78]. Policy implications of our results are discussed.

Development of a microlesson in teaching energy levels of atoms

Science.gov (United States)

Rodriguez, Cherilyn A.; Buan, Amelia T.

2018-01-01

Energy levels of atoms is one of the difficult topics in understanding atomic structure of matter. It appears tobe abstract, theoretical and needs visual representation and images. Hence, in this study a microlesson in teaching the high school chemistry concept on the energy levels of atoms is developed and validated. The researchers utilized backward curriculum design in planning the microlesson to meet the standards of the science K-12 curriculum. The planning process of the microlesson involved a) Identifying the learning competencies in K-12 science curriculum b) write learning objectives c) planning of assessment tools d) making a storyboard e) designing the microlesson and validate and revise the microlesson. The microlesson made use of varied resources in the internet from which the students accessed and collected information about energy levels of atoms. Working in groups, the students synthesized the information on how and why fireworks produce various colors of light through a post card. Findings of the study showed that there was an increase of achievement in learning the content and the students were highly motivated to learn chemistry. Furthermore, the students perceived that the microlesson helped them to understand the chemistry concept through the use of appropriate multimedia activities.

Energy Levels of Hydrogen and Deuterium

Science.gov (United States)

SRD 142 NIST 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.

Landau levels in biased graphene structures with monolayer-bilayer interfaces

Science.gov (United States)

Mirzakhani, M.; Zarenia, M.; Vasilopoulos, P.; Ketabi, S. A.; Peeters, F. M.

2017-09-01

The electron energy spectrum in monolayer-bilayer-monolayer and in bilayer-monolayer-bilayer graphene structures is investigated and the effects of a perpendicular magnetic field and electric bias are studied. Different types of monolayer-bilayer interfaces are considered as zigzag (ZZ) or armchair (AC) junctions which modify considerably the bulk Landau levels (LLs) when the spectra are plotted as a function of the center coordinate of the cyclotron orbit. Far away from the two interfaces, one obtains the well-known LLs for extended monolayer or bilayer graphene. The LL structure changes significantly at the two interfaces or junctions where the valley degeneracy is lifted for both types of junctions, especially when the distance between them is approximately equal to the magnetic length. Varying the nonuniform bias and the width of this junction-to-junction region in either structure strongly influence the resulting spectra. Significant differences exist between ZZ and AC junctions in both structures. The densities of states (DOSs) for unbiased structures are symmetric in energy whereas those for biased structures are asymmetric. An external bias creates interface LLs in the gaps between the LLs of the unbiased system in which the DOS can be quite small. Such a pattern of LLs can be probed by scanning tunneling microscopy.

New levels of Ta II with energies higher than 72,000 cm−1

International Nuclear Information System (INIS)

Uddin, Zaheer; Windholz, Laurentius

2014-01-01

We studied the hyperfine structure of Tantalum lines appearing in a high-resolution Fourier transform spectrum. Hundreds of lines of Ta in this spectrum are still unclassified; most of them, especially in the UV region, belong to Ta II. When investigating such lines we found 14 new levels of Ta II. These new levels are the highest-lying known Ta II levels and do not belong to the already known configurations. - Highlights: • We report the discovery of 14 even energy levels of the first ion of Tantalum (Ta II). • Their energy ranges from 72,000 to 81,000 cm −1 . • For comparison, up to now only even levels between 0 and 44,000 cm −1 were known. • These levels belong to up to now unknown electron configurations. • With help of these levels, approximately 100 spectral lines of Ta II can be classified

Energy Hub’s Structural and Operational Optimization for Minimal Energy Usage Costs in Energy Systems

Directory of Open Access Journals (Sweden)

Thanh Tung Ha

2018-03-01

Full Text Available The structural and optimal operation of an Energy Hub (EH has a tremendous influence on the hub’s performance and reliability. This paper envisions an innovative methodology that prominently increases the synergy between structural and operational optimization and targets system cost affordability. The generalized energy system structure is presented theoretically with all selective hub sub-modules, including electric heater (EHe and solar sources block sub-modules. To minimize energy usage cost, an energy hub is proposed that consists of 12 kinds of elements (i.e., energy resources, conversion, and storage functions and is modeled mathematically in a General Algebraic Modeling System (GAMS, which indicates the optimal hub structure’s corresponding elements with binary variables (0, 1. Simulation results contrast with 144 various scenarios established in all 144 categories of hub structures, in which for each scenario the corresponding optimal operation cost is previously calculated. These case studies demonstrate the effectiveness of the suggested model and methodology. Finally, avenues for future research are also prospected.

Enhancing multiphoton upconversion through energy clustering at sublattice level

Science.gov (United States)

Wang, Juan; Deng, Renren; MacDonald, Mark A.; Chen, Bolei; Yuan, Jikang; Wang, Feng; Chi, Dongzhi; Andy Hor, Tzi Sum; Zhang, Peng; Liu, Guokui; Han, Yu; Liu, Xiaogang

2014-02-01

The applications of lanthanide-doped upconversionnanocrystals in biological imaging, photonics, photovoltaics and therapeutics have fuelled a growing demand for rational control over the emission profiles of the nanocrystals. A common strategy for tuning upconversion luminescence is to control the doping concentration of lanthanide ions. However, the phenomenon of concentration quenching of the excited state at high doping levels poses a significant constraint. Thus, the lanthanide ions have to be stringently kept at relatively low concentrations to minimize luminescence quenching. Here we describe a new class of upconversion nanocrystals adopting an orthorhombic crystallographic structure in which the lanthanide ions are distributed in arrays of tetrad clusters. Importantly, this unique arrangement enables the preservation of excitation energy within the sublattice domain and effectively minimizes the migration of excitation energy to defects, even in stoichiometric compounds with a high Yb3+ content (calculated as 98 mol%). This allows us to generate an unusual four-photon-promoted violet upconversion emission from Er3+ with an intensity that is more than eight times higher than previously reported. Our results highlight that the approach to enhancing upconversion through energy clustering at the sublattice level may provide new opportunities for light-triggered biological reactions and photodynamic therapy.

Enhancing multiphoton upconversion through energy clustering at sublattice level

KAUST Repository

Wang, Juan

2013-11-24

The applications of lanthanide-doped upconversionnanocrystals in biological imaging, photonics, photovoltaics and therapeutics have fuelled a growing demand for rational control over the emission profiles of the nanocrystals. A common strategy for tuning upconversion luminescence is to control the doping concentration of lanthanide ions. However, the phenomenon of concentration quenching of the excited state at high doping levels poses a significant constraint. Thus, the lanthanide ions have to be stringently kept at relatively low concentrations to minimize luminescence quenching. Here we describe a new class of upconversion nanocrystals adopting an orthorhombic crystallographic structure in which the lanthanide ions are distributed in arrays of tetrad clusters. Importantly, this unique arrangement enables the preservation of excitation energy within the sublattice domain and effectively minimizes the migration of excitation energy to defects, even in stoichiometric compounds with a high Yb 3+ content (calculated as 98 mol%). This allows us to generate an unusual four-photon-promoted violet upconversion emission from Er 3+ with an intensity that is more than eight times higher than previously reported. Our results highlight that the approach to enhancing upconversion through energy clustering at the sublattice level may provide new opportunities for light-triggered biological reactions and photodynamic therapy. © 2014 Macmillan Publishers Limited. All rights reserved.

Evolution of energy structures

International Nuclear Information System (INIS)

Nifenecker, H.

2005-01-01

Because of the big inertia and long time constants of energy systems, their long-time behaviour is mainly determined by their present day state and by the trends of their recent evolution. For this reason, it is of prime importance to foresee the evolution of the different energy production sources which may play an important role in the future. A status of the world energy consumption and production is made first using the energy statistics of the IEA. Then, using the trends observed since 1973, the consequences of a simple extrapolation of these trends is examined. Finally, the scenarios of forecasting of energy structures, like those supplied by the International institute for applied systems analysis (IIASA) are discussed. (J.S.)

What drives the change in China's energy intensity: Combining decomposition analysis and econometric analysis at the provincial level

International Nuclear Information System (INIS)

Song, Feng; Zheng, Xinye

2012-01-01

We employ decomposition analysis and econometric analysis to investigate the driving forces behind China's changing energy intensity using a provincial-level panel data set for the period from 1995 to 2009. The decomposition analysis indicates that: (a) all of the provinces except for a few experienced efficiency improvement, while around three-fourths of the provinces' economics became more energy intensive or remained unchanged; (b) consequently the efficiency improvement accounts for more than 90% of China's energy intensity change as opposed to the economic structural change. The econometric analysis shows that the rising income plays a significant role in the reduction of energy intensity while the effect of energy price is relatively limited. The result may reflect the urgency of deregulating the price and establishing a market-oriented pricing system in China's energy sector. The implementation of the energy intensity reduction policies in the Eleventh Five-Year Plan (FYP) has helped reverse the increasing trend of energy intensity since 2002. Although the Chinese Government intended to change the industry-led economic growth pattern, it seems that most of the policy effects flow through the efficiency improvement as opposed to the economic structure adjustment. More fundamental changes to the economic structure are needed to achieve more sustainable progress in energy intensity reduction. - Highlights: ► We examine the determinants of China's energy intensity change at provincial level. ► Rising income plays a significant role in reducing China's energy intensity. ► Policy effects mainly flow through the efficiency improvement. ► Fundamental structure changes are needed to further reduce China's energy intensity.

Correlation between electronic structure and energy band in Eu-doped CuInTe2 semiconductor compound with chalcopyrite structure

Institute of Scientific and Technical Information of China (English)

Tai Wang; Yong-Quan Guo; Shuai Li

2017-01-01

The Eu-doped Cu(In,Eu)Te2 semiconductors with chalcopyrite structures are promising materials for their applications in the absorption layer for thin-film solar cells due to their wider band-gaps and better optical properties than those of CulnTe2.In this paper,the Eu-doped CulnTe2 (Culn1-xEuxTe2,x =0,0.1,0.2,0.3) are studied systemically based on the empirical electron theory (EET).The studies cover crystal structures,bonding regularities,cohesive energies,energy levels,and valence electron structures.The theoretical values fit the experimental results very well.The physical mechanism of a broadened band-gap induced by Eu doping into CuInTe2 is the transitions between different hybridization energy levels induced by electron hopping between s and d orbitals and the transformations from the lattice electrons to valence electrons for Cu and In ions.The research results reveal that the photovoltaic effect induces the increase of lattice electrons of In and causes the electric resistivity to decrease.The Eu doping into CuInTe2 mainly influences the transition between different hybridization energy levels for Cu atoms,which shows that the 3d electron numbers of Cu atoms change before and after Eu doping.In single phase CuIn1-xEuxTe2,the number of valence electrons changes regularly with increasing Eu content,and the calculated band gap Eg also increases,which implies that the optical properties of Eu-doped CuIn1-xEuxTe2 are improved.

The difference between energy consumption and energy cost: Modelling energy tariff structures for water resource recovery facilities.

Science.gov (United States)

Aymerich, I; Rieger, L; Sobhani, R; Rosso, D; Corominas, Ll

2015-09-15

The objective of this paper is to demonstrate the importance of incorporating more realistic energy cost models (based on current energy tariff structures) into existing water resource recovery facilities (WRRFs) process models when evaluating technologies and cost-saving control strategies. In this paper, we first introduce a systematic framework to model energy usage at WRRFs and a generalized structure to describe energy tariffs including the most common billing terms. Secondly, this paper introduces a detailed energy cost model based on a Spanish energy tariff structure coupled with a WRRF process model to evaluate several control strategies and provide insights into the selection of the contracted power structure. The results for a 1-year evaluation on a 115,000 population-equivalent WRRF showed monthly cost differences ranging from 7 to 30% when comparing the detailed energy cost model to an average energy price. The evaluation of different aeration control strategies also showed that using average energy prices and neglecting energy tariff structures may lead to biased conclusions when selecting operating strategies or comparing technologies or equipment. The proposed framework demonstrated that for cost minimization, control strategies should be paired with a specific optimal contracted power. Hence, the design of operational and control strategies must take into account the local energy tariff. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Structural Changes in the Economy of Ukraine and its Energy Intensity

Directory of Open Access Journals (Sweden)

Kyzym Mykola O.

2017-12-01

Full Text Available The article is concerned with an analysis of structural changes in the economy of Ukraine in view of energy intensity of types of economic activity (TEA. On considering the main tendencies of development of Ukraine’s economy in 2000 – 2015, it has been proved that, unlike the world economy, its development is of more unevenly nature. In order to research structural changes in the domestic economy in the period from 2000 to 2015, the methodical approach consisting of a number of interconnected stages has been proposed. Using this approach: the structure of economy of Ukraine by TEA has been analyzed, the classification and structure of the TEA distribution by their importance have been suggested; the dynamics of TEA of Ukraine have been analyzed, the classification and structure of distribution of Ukraine’s TEA by dynamics of development has been proposed; a matrix of positioning of the TEA of Ukraine in the plane of «proportion – rate of change» has been built; the values have been calculated and directions of structural changes of TEA in economy of Ukraine have been defined; a characterization of the TEA of economy of Ukraine as to the degree of materiality of structural shift has been formed; the integral coefficients of structural shifts in economy for the studied period have been calculated; the classification of the TEA of Ukraine according to the level of energy intensity has been developed, the structure of economy by the energy intensity groups has been presented; the indices have been calculated and directions of structural shifts of groups with different energy intensity of TEA have been determined; the integral coefficients of structural shift of economy due to the groups of TEA with different energy intensity have been calculated; the general characterization of structural shifts of the TEA of Ukraine in 2000 – 2015 has been formed.

Energies and electric dipole transitions for low-lying levels of protactinium IV and uranium V

Energy Technology Data Exchange (ETDEWEB)

Uerer, Gueldem; Oezdemir, Leyla [Sakarya Univ. (Turkey). Physics Dept.

2012-01-15

We have reported a relativistic multiconfiguration Dirac-Fock (MCDF) study on low-lying level structures of protactinium IV (Z = 91) and uranium V (Z = 92) ions. Excitation energies and electric dipole (E1) transition parameters (wavelengths, oscillator strengths, and transition rates) for these low-lying levels have been given. We have also investigated the influence of the transverse Breit and quantum electrodynamic (QED) contributions besides correlation effects on the level structure. A comparison has been made with a few available data for these ions in the literature. (orig.)

The Energy Economics of Financial Structuring for Renewable Energy Projects

Science.gov (United States)

Rana, Vishwajeet

2011-12-01

This dissertation focuses on the various financial structuring options for the renewable energy sector. The projects in this sector are capital-intensive to build but have relatively low operating costs in the long run when compared to traditional energy resources. The large initial capital requirements tend to discourage investors. To encourage renewable investments the government needs to provide financial incentives. Since these projects ultimately generate returns, the government's monetary incentives go to the sponsors and tax equity investors who build and operate such projects and invest capital in them. These incentives are usually in the form of ITCs, PTCs and accelerated depreciation benefits. Also, in some parts of the world, carbon credits are another form of incentive for the sponsors and equity investors to invest in such turnkey projects. The relative importance of these various considerations, however, differs from sponsor to sponsor, investor to investor and from project to project. This study focuses mainly on the US market, the federal tax benefits and incentives provided by the government. This study focuses on the energy economics that are used for project decision-making and parties involved in the transaction as: Project Developer/Sponsor, Tax equity investor, Debt investor, Energy buyer and Tax regulator. The study fulfils the knowledge gap in the decision making process that takes advantage of tax monetization in traditional after-tax analysis for renewable energy projects if the sponsors do not have the tax capacity to realize the total benefits of the project. A case-study for a wind farm, using newly emerging financial structures, validates the hypothesis that these renewable energy sources can meet energy industry economic criteria. The case study also helps to validate the following hypotheses: a) The greater a sponsor's tax appetite, the tower the sponsor's equity dilution. b) The use of leverage increases the cost of equity financing

Characterizing structural transitions using localized free energy landscape analysis.

Directory of Open Access Journals (Sweden)

Nilesh K Banavali

Full Text Available Structural changes in molecules are frequently observed during biological processes like replication, transcription and translation. These structural changes can usually be traced to specific distortions in the backbones of the macromolecules involved. Quantitative energetic characterization of such distortions can greatly advance the atomic-level understanding of the dynamic character of these biological processes.Molecular dynamics simulations combined with a variation of the Weighted Histogram Analysis Method for potential of mean force determination are applied to characterize localized structural changes for the test case of cytosine (underlined base flipping in a GTCAGCGCATGG DNA duplex. Free energy landscapes for backbone torsion and sugar pucker degrees of freedom in the DNA are used to understand their behavior in response to the base flipping perturbation. By simplifying the base flipping structural change into a two-state model, a free energy difference of upto 14 kcal/mol can be attributed to the flipped state relative to the stacked Watson-Crick base paired state. This two-state classification allows precise evaluation of the effect of base flipping on local backbone degrees of freedom.The calculated free energy landscapes of individual backbone and sugar degrees of freedom expectedly show the greatest change in the vicinity of the flipping base itself, but specific delocalized effects can be discerned upto four nucleotide positions away in both 5' and 3' directions. Free energy landscape analysis thus provides a quantitative method to pinpoint the determinants of structural change on the atomic scale and also delineate the extent of propagation of the perturbation along the molecule. In addition to nucleic acids, this methodology is anticipated to be useful for studying conformational changes in all macromolecules, including carbohydrates, lipids, and proteins.

Energy security issues at household level in India

International Nuclear Information System (INIS)

Jain, Garima

2010-01-01

Energy security at the household level implies ensuring assured and regular supply of clean energy fuels at an affordable price for various household activities. Threat to physical availability of clean energy fuels for cooking and lighting is determined through various indicators such as dependence on traditional fuels and limited access to clean fuels. Energy insecurity translates into various adverse social impacts. Financial threat to energy security is indicated by expenses incurred on energy fuels and affordability of clean fuels. Households spend a major portion of their income on acquiring energy fuels; however, due to high price of clean fuels, they continue to depend on traditional and inefficient fuels. There is an urgent need to address factors that pose a threat to energy security at the household level. In this regard, measures taken by the government agencies and other institutions are also reviewed. The paper also suggests the regulatory and policy interventions required to address the energy security issues at the household level.

Measuring structural change and energy use. Decomposition of the US economy from 1997 to 2002

International Nuclear Information System (INIS)

Weber, Christopher L.

2009-01-01

The steadily increasing focus on energy production and consumption has led to growing research attention to patterns of energy use within economies. Of particular interest has been comparing the driving forces of increasing efficiency and economic structural change. Input-output analysis (IOA) and decomposition analysis have become critical tools for performing such analyses. This study analyzes aggregate energy use in the United States in 1997 and 2002 to discover the causes of changing energy usage and flows. Results show that rising population and household consumption acted to drive up energy demand, but this driving force was offset by considerable structural change within the economy, particularly related to a quickly increasing trade deficit in manufacturing goods. Thus, while total energy intensity, the ratio of energy use to economic output, declined by approximately 12% between 1997 and 2002, changes in the structure of the economy explain this drop more than increased energy efficiency. The level of aggregation at which decomposition analyses are run was identified as a crucially sensitive parameter for the determination of structural change, and future studies should specifically address the amount of detail necessary to adequately measure changes in economic structure. (author)

Low-energy linac structure for PIGMI

International Nuclear Information System (INIS)

Swenson, D.A.; Stovall, J.E.

1977-01-01

The higher radio frequency (450 MHz) and lower injection energy (250 keV) of the PIGMI (Pion Generator for Medical Irradiations) linac design seriously compound the problem of beam containment in the first few meters of the structure. The conventional quadrupole-focused, drift-tube linac represents the best solution for beam energies above 8 MeV, but because of the small space available for quadrupoles in the PIGMI designs, cannot provide the required focusing at lower energies. A satisfactory solution to this focusing problem has been found based on pure alternating phase focusing for the first few MeV, followed by a smooth transition to a pure permanent magnet quadrupole-focused structure at 8 MeV. The structure and its calculated performance are described

Analysis of the importance of structural change in non-energy intensive industry for prospective modelling: The French case

International Nuclear Information System (INIS)

Seck, Gondia Sokhna; Guerassimoff, Gilles; Maïzi, Nadia

2016-01-01

A large number of studies have been conducted on the contribution of technological progress and structural change to the evolution of aggregate energy intensity in the industrial sector. However, no analyses have been done to examine theses changes in the non-energy intensive industry in France. We analyzed their importance in French industry with respect to their energy intensity, energy costs, value added, labour and the diffusion of production sites by using data at the 3-digit level with 236 sectors. Using a new decomposition method that gives no residual, this paper attempted to examine, over 10 years from 1996 to 2005, the changes that occurred in an area that has been neglected in energy analysis. We found that structural change had an overwhelming effect on the decline of aggregate energy intensity. Furthermore, we found that the higher the level of sector disaggregation, the more significant the changes that can be attributed to structural change, due to the homogeneity of this industrial group. The results of our study show that it is important to take into account the effects of structural change in “bottom-up” modelling exercises so as to improve the accuracy of energy demand forecasting for policy-makers and scientists. - Highlights: • Defining NEI industries with a quantitative approach from relevant indicators in France. • Developing new decomposition method given in additive form with no residual in NEI. • Structural change is the overwhelming factor in improving energy performance within NEI. • Revealed consistent trend with level of sector disaggregation if homogeneous industries.

Absolute Hydration Free Energy of Proton from First Principles Electronic Structure Calculations

International Nuclear Information System (INIS)

Zhan, Chang-Guo; Dixon, David A.

2001-01-01

The absolute hydration free energy of the proton, DGhyd298(H+), is one of the fundamental quantities for the thermodynamics of aqueous systems. Its exact value remains unknown despite extensive experimental and computational efforts. We report a first-principles determination of DGhyd298(H+) by using the latest developments in electronic structure theory and massively parallel computers. DGhyd298(H+) is accurately predicted to be -262.4 kcal/mol based on high-level, first-principles solvation-included electronic structure calculations. The absolute hydration free energies of other cations can be obtained by using appropriate available thermodynamic data in combination with this value. The high accuracy of the predicted absolute hydration free energy of proton is confirmed by applying the same protocol to predict DGhyd298(Li+)

Level structure in 123Xe

International Nuclear Information System (INIS)

Luukko, A.; Hattula, J.; Helppi, H.; Knuuttila, O.

1980-09-01

The level structure of 123 Xe has been studied with 122 Te( 3 He,2n) and 123 Te( 3 He,3n) reactions using in-beam γ-ray spectroscopic methods. Band-like level structures based on the unique-parity hsub(11/2) neutron state and different low-j states are observed. The isomeric state proposed earlier is established at 185.4 keV with a half-life of 5.6+-0.3 μs, and a new spin assignment of 7/2 - is proposed for this level. A triaxial-rotor-model calculation has been performed to interprete the negative-parity level system. Because of the 7/2 - state, we do not obtain a consistent description of the negative-parity states with the triaxial rotor model, unlike the heavier odd-A Xe nuclei. On the other hand, the positive-parity level structures are interpreted in terms of the core-quasiparticle model supposing a vibrational core. This indicates different core shapes for the positive- and negative-parity level systems. (author)

Optogalvanic spectroscopy of the hyperfine structure of weak La I lines: discovery of new even parity fine structure levels

International Nuclear Information System (INIS)

Siddiqui, Imran; Khan, Shamim; Gamper, B; Windholz, L; Dembczyński, J

2013-01-01

The hyperfine structure of weak La I lines was experimentally investigated using laser optogalvanic spectroscopy in a hollow cathode discharge lamp. More than 100 La I lines were investigated and 40 new energy levels were discovered, most of them having even parity. The magnetic hyperfine interaction constants A and in some cases the electric quadrupole interaction constants B for these levels were determined. All the newly discovered levels were confirmed either by additional laser excitations (from other known levels) or by lines in a Fourier transform spectrum which could now be classified. (paper)

Marine Structures: consuming and producing energy

DEFF Research Database (Denmark)

Pedersen, Preben Terndrup; Jensen, Jørgen Juncher

2009-01-01

and hydrocarbons. • The oceans receive 70 % of our primary sustainable energy source, i.e. the radiation from the sun; this thermal energy can be harvested in the form of thermal, wind, current or wave energy, salt gradients etc. To exploit these possibilities marine structures are required....

Spectrum and energy levels of Y VI

International Nuclear Information System (INIS)

Persson, W.; Reader, J.

1986-01-01

The spectrum of the five-times-ionized yttrium atom (Y VI), excited in a sliding-spark discharge, was studied in the 160--2500 A-circle range. About 900 Y VI lines were classified as transitions between 101 odd and 69 even energy levels.The energy-level system established includes almost all levels of the 4s 2 4p 4 , 4s4p 5 , 4s 2 4p 3 4d, 5d, 5s, 6s, and 5p configurations and a number of levels of the 7s, 4f, and 4s4p 4 4d configurations. The observed level system has been theoretically interpreted by means of Hartree--Fock calculations and least-squares parametric fits. Strong configuration mixings are found between the 4s4p 5 and 4s 2 4p 3 4d configurations, between the 4s 2 4p 3 5p and 4s4p 4 4d configurations, and between the 4s 2 4p 3 4f and 4s4p 4 4d configurations. From the optimized energy-level values, a system of Ritz-type wavelength standards with accuracies varying from 0.0003 to 0.003 A-circle in the range 179--500 A-circle has been determined. The ionization energy as determined from 4s 2 4p 3 ns levels (n = 5-7) is 737 110 +- 200 cm/sup -1/ (91.390 +- 0.025 eV)

Evolution of energy structures; Evolution des structures energetiques

Energy Technology Data Exchange (ETDEWEB)

Nifenecker, H. [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France)

2005-07-01

Because of the big inertia and long time constants of energy systems, their long-time behaviour is mainly determined by their present day state and by the trends of their recent evolution. For this reason, it is of prime importance to foresee the evolution of the different energy production sources which may play an important role in the future. A status of the world energy consumption and production is made first using the energy statistics of the IEA. Then, using the trends observed since 1973, the consequences of a simple extrapolation of these trends is examined. Finally, the scenarios of forecasting of energy structures, like those supplied by the International institute for applied systems analysis (IIASA) are discussed. (J.S.)

Hydrodynamic Behavior of Overtopping Wave Energy Converters Built in Sea Defense Structures

DEFF Research Database (Denmark)

Victor, Lander; Kofoed, Jens Peter; Troch, Peter

2010-01-01

Many sea defense structures need to be adapted to the rising sea water level and changing wave climate due to global warming. The accordingly required investment opens perspectives for wave energy converters (WECs) – that are built as part of the sea defense structures – to become economically...... viable. In this paper the average overtopping discharges q of overtopping wave energy devices built in sea defense structures are studied. Physical model tests with this type of devices have been carried out in a wave flume leading to experimental q - values. The experimental q -values are compared...... with predicted average overtopping discharges by existing empirical formulae from literature. Overtopping converters have low relative crest freeboards and smooth slope characteristics to maximize overtopping, which is contradictive to the basic role of sea defense structures. As a consequence, the achieved...

Modeling level structures of odd-odd deformed nuclei

International Nuclear Information System (INIS)

Hoff, R.W.; Kern, J.; Piepenbring, R.; Boisson, J.P.

1984-01-01

A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation were derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings were used. Calculated and experimental level structures for 238 Np, 244 Am, and 250 Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Corresponding average deviations for five rare-earth nuclei are 47 keV and 7%. Several applications of this modeling technique are discussed. 18 refs., 5 figs., 4 tabs

Structures and perspectives of the Austrian energy system

International Nuclear Information System (INIS)

Wohlgemut, N.

1992-03-01

The technical tools for projecting future energy demand can be grouped into two broad categories: Firstly, time series or cross section data based econometric models which contain information about customers' past behavior and thus enable to judge the causal effects of economic factors like incomes and prices on energy demand (passive forecasting). Secondly, structural simulation models which indicate how energy services transform to flows of useful, final and primary energy. These models enable to estimate the technical potential of improving the energy application and energy transformation systems (active scenario approach). Comparison of the two approaches with respect to projections for future energy demand yields that, typically, in the short run of econometric approach will dominate the structural simulation model. In the long run, however, this relation will be reversed. The econometric models suffer lack of technical information necessary to describe the demand for energy. The structural simulation model enables an incorporation of technical factors like efficiencies and fuel shares. An application of the structural model is a simulation run describing a scenario in order to reduce the Austrian CO 2 -emissions according to the recommendations of the conference of Toronto

New even parity energy levels of Pr I found by excitation of transitions in the region 560 - 695 nm

Energy Technology Data Exchange (ETDEWEB)

Syed, Tanweer Iqbal; Khan, Shamim; Imran, Siddiqui; Zaheer, Uddin; Windholz, Laurentius [Inst. f. Experimentalphysik, Techn. Univ. Graz, Petersgasse 16, A-8010 Graz (Austria)

2011-07-01

The knowledge of electronic levels is essentially needed for a description of the interactions between the electrons of an atom and for the classification of an atomic spectrum. We have studied the hyperfine structure of Praseodymium spectral lines in the region from 560 to 695 nm. The hyperfine structure of a large number of unclassified Pr I-lines have been investigated by using the method of laser induced fluorescence in a hollow cathode discharge. During this investigation, we have discovered twelve energy levels with even parity, which were previously unknown. The excitation source was a ring dye laser operated with R6G, Kiton red, or DCM. J-quantum numbers and magnetic dipole interaction constants A for upper and lower levels have been determined from the recorded hyperfine structures. The energies of new levels have been determined by using these constants, excitation and fluorescence wavelengths. Promising excitation wavelengths have been taken from Fourier transform spectra. The new levels were confirmed by at least one second laser excitation.

Modelling the multilevel structure and mixed effects of the factors influencing the energy consumption of electric vehicles

International Nuclear Information System (INIS)

Liu, Kai; Wang, Jiangbo; Yamamoto, Toshiyuki; Morikawa, Takayuki

2016-01-01

Highlights: • The impacts of driving heterogeneity on EVs’ energy efficiency are examined. • Several multilevel mixed-effects regression models are proposed and compared. • The most reasonable nested structure is extracted from the long term GPS data. • Proposed model improves the energy estimation accuracy by 7.5%. - Abstract: To improve the accuracy of estimation of the energy consumption of electric vehicles (EVs) and to enable the alleviation of range anxiety through the introduction of EV charging stations at suitable locations for the near future, multilevel mixed-effects linear regression models were used in this study to estimate the actual energy efficiency of EVs. The impacts of the heterogeneity in driving behaviour among various road environments and traffic conditions on EV energy efficiency were extracted from long-term daily trip-based energy consumption data, which were collected over 12 months from 68 in-use EVs in Aichi Prefecture in Japan. Considering the variations in energy efficiency associated with different types of EV ownership, different external environments, and different driving habits, a two-level random intercept model, three two-level mixed-effects models, and two three-level mixed-effects models were developed and compared. The most reasonable nesting structure was determined by comparing the models, which were designed with different nesting structures and different random variance component specifications, thereby revealing the potential correlations and non-constant variability of the energy consumption per kilometre (ECPK) and improving the estimation accuracy by 7.5%.

Broadband energy harvesting using acoustic black hole structural tailoring

International Nuclear Information System (INIS)

Zhao, Liuxian; Semperlotti, Fabio; Conlon, Stephen C

2014-01-01

This paper explores the concept of an acoustic black hole (ABH) as a main design framework for performing dynamic structural tailoring of mechanical systems for vibration energy harvesting applications. The ABH is an integral feature embedded in the host structure that allows for a smooth reduction of the phase velocity, theoretically approaching zero, while minimizing the reflected energy. This mechanism results in structural areas with high energy density that can be effectively exploited to develop enhanced vibration-based energy harvesting. Fully coupled electro-mechanical models of an ABH tapered structure with surface mounted piezo-transducers are developed to numerically simulate the response of the system to both steady state and transient excitations. The design performances are numerically evaluated using structural intensity data as well as the instantaneous voltage/power and energy output produced by the piezo-transducer network. Results show that the dynamically tailored structural design enables a drastic increase in the harvested energy as compared to traditional structures, both under steady state and transient excitation conditions. (papers)

Innovation in Multi-Level Governance for Energy Efficiency. Sharing experience with multi-level governance to enhance energy efficiency. Information paper

Energy Technology Data Exchange (ETDEWEB)

Jollands, Nigel; Gasc, Emilien; Pasquier, Sara Bryan

2009-12-15

Despite creating a plethora of national and international regulations and voluntary programmes to improve energy efficiency, countries are far from achieving full energy efficiency potential across all sectors of the economy. One major challenge, among numerous barriers, is policy implementation. One strategy that many national governments and international organisations have used to address the implementation issue is to engage regional and local authorities. To that end, many programmes have been created that foster energy efficiency action and collaboration across levels of government. The aim of this report is to identify trends and detail recent developments in multi-level governance in energy efficiency (MLGEE). By sharing lessons learned from daily practitioners in the field, the IEA hopes energy efficiency policy makers at all levels of government will be able to identify useful multilevel governance (MLG) practices across geographical and political contexts and use these to design robust programmes; modify existing programmes, and connect and share experiences with other policy makers in this field.

Multi-Level Experimental and Analytical Evaluation of Two Composite Energy Absorbers

Science.gov (United States)

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.

Electronic structure of free and doped actinides: N and Z dependences of energy levels and electronic structure parameters

International Nuclear Information System (INIS)

Kulagin, N.

2005-01-01

Theoretical study of electronic structure of antinide ions and its dependence on N and Z are presented in this paper. The main 5f N and excited 5f N n'l' N' configurations of actinides have been studied using Hartree-Fock-Pauli approximation. Results of calculations of radial integrals and the energy of X-ray lines for all 5f ions with electronic state AC +1 -AC +4 show approximate dependence on N and Z. A square of N and cubic of Z are ewalized for the primary electronic parameters of the actinides. Theoretical values of radial integrals for free actinides and for ions in a cluster AC +n :[L] k are compared, too

Energy Levels and Spectral Lines of Li Atoms in White Dwarf Strength Magnetic Fields

Science.gov (United States)

Zhao, L. B.

2018-04-01

A theoretical approach based on B-splines has been developed to calculate atomic structures and discrete spectra of Li atoms in a strong magnetic field typical of magnetic white dwarf stars. Energy levels are presented for 20 electronic states with the symmetries 20+, 20‑, 2(‑1)+, 2(‑1)‑, and 2(‑2)+. The magnetic field strengths involved range from 0 to 2350 MG. The wavelengths and oscillator strengths for the electric dipole transitions relevant to these magnetized atomic states are reported. The current results are compared to the limited theoretical data in the literature. A good agreement has been found for the lower energy levels, but a significant discrepancy is clearly visible for the higher energy levels. The existing discrepancies of the wavelengths and oscillator strengths are also discussed. Our investigation shows that the spectrum data of magnetized Li atoms previously published are obviously far from meeting requirements of analyzing discrete atomic spectra of magnetic white dwarfs with lithium atmospheres.

The structure and the analytical potential energy function of NH2 (X2B1)

International Nuclear Information System (INIS)

Liu Yufang; Jiang Lijuan; Ma Heng; Sun Jinfeng

2008-01-01

This paper reports that the equilibrium structure of NH 2 has been optimized at the QCISD/6-311++G (3df, 3pd) level. The ground-state NH 2 has a bent (C 2v , X 2 B 1 ) structure with an angle of 103.0582°. The geometrical structure is in good agreement with the other calculational and experimental results. The harmonic frequencies and the force constants have also been calculated. Based on the group theory and the principle of microscopic reversibility, the dissociation limits of NH 2 (C 2v , X 2 B 1 ) have been derived. The potential energy surface of NH 2 (X 2 B 1 ) is reasonable. The contour lines are constructed, the structure and energy of NH 2 reappear on the potential energy surface

Comparing energy levels in isotropic and anisotropic potentials

Energy Technology Data Exchange (ETDEWEB)

Pikovski, Alexander, E-mail: alexander.pikovski@colorado.edu

2015-11-06

Qualitative information about the quantized energy levels of a system can be of great value. We study the relationship between the bound-state energies of an anisotropic potential and those of its spherical average. It is shown that the two ground-state energies satisfy an inequality, and there is a similar inequality for the first excited states. - Highlights: • Quantized energy levels in an arbitrary non-central potential are studied. • We derive inequalities between energies in a potential and its spherical average. • The results hold in three and two dimensions for any ground state and, with additional symmetry requirements for the first excited state.

Comparing energy levels in isotropic and anisotropic potentials

International Nuclear Information System (INIS)

Pikovski, Alexander

2015-01-01

Qualitative information about the quantized energy levels of a system can be of great value. We study the relationship between the bound-state energies of an anisotropic potential and those of its spherical average. It is shown that the two ground-state energies satisfy an inequality, and there is a similar inequality for the first excited states. - Highlights: • Quantized energy levels in an arbitrary non-central potential are studied. • We derive inequalities between energies in a potential and its spherical average. • The results hold in three and two dimensions for any ground state and, with additional symmetry requirements for the first excited state.

Total energy calculations for structural phase transformations

International Nuclear Information System (INIS)

Ye, Y.Y.; Chan, C.T.; Ho, K.M.; Harmon, B.N.

1990-01-01

The structural integrity and physical properties of crystalline solids are frequently limited or enhanced by the occurrence of phase transformations. Martensitic transformations involve the collective displacement of atoms from one ordered state to another. Modern methods to determine the microscopic electronic changes as the atoms move are now accurate enough to evaluate the very small energy differences involved. Extensive first principles calculations for the prototypical martensitic transformation from body-centered cubic (bcc) to closepacked 9R structure in sodium metal are described. The minimum energy coordinate or configuration path between the bcc and 9R structures is determined as well as paths to other competing close-packed structures. The energy barriers and important anharmonic interactions are identified and general conclusions drawn. The calculational methods used to solve the Schrodinger equation include pseudopotentials, fast Fourier transforms, efficient matrix diagnonalization, and supercells with many atoms

Meso-level analysis, the missing link in energy strategies

International Nuclear Information System (INIS)

Schenk, Niels J.; Moll, Henri C.; Schoot Uiterkamp, Anton J.M.

2007-01-01

Energy is essential for human societies. Energy systems, though, are also associated with several adverse environmental effects. So far societies have been unable to successfully change their energy systems in a way that addresses environmental and health concerns. Lack of policy consensus often resulted in so-called 'stop-go' policies, which were identified as some of the most important barriers regarding successful energy transitions. The lack of policy consensus and coherent long-term strategies may result from a lack of knowledge of energy systems' meso-level dynamics. The meso-level involves the dynamic behaviour of the individual system elements and the coupling of individual technologies, resulting in interdependencies and regimes. Energy systems are at the meso-level characterised by two typical aspects, i.e. dynamics driven by interactions between actors, and heterogeneous characteristics of actors. These aspects give rise to the ineffectiveness of traditional energy policies, which is illustrated with examples from the transport sector and household electricity consumption. We found that analysis of energy systems at the meso-level helps to better understand energy systems. To resolve persistent policy issues, the traditional 'one size fits all' energy policies are not sufficient. In order to tackle the difficult issues, 'redesign of system organisation', 'target group approach', or 'target group induced system re-orientation' are needed

Energy index decomposition methodology at the plant level

Science.gov (United States)

Kumphai, Wisit

Scope and method of study. The dissertation explores the use of a high level energy intensity index as a facility-level energy performance monitoring indicator with a goal of developing a methodology for an economically based energy performance monitoring system that incorporates production information. The performance measure closely monitors energy usage, production quantity, and product mix and determines the production efficiency as a part of an ongoing process that would enable facility managers to keep track of and, in the future, be able to predict when to perform a recommissioning process. The study focuses on the use of the index decomposition methodology and explored several high level (industry, sector, and country levels) energy utilization indexes, namely, Additive Log Mean Divisia, Multiplicative Log Mean Divisia, and Additive Refined Laspeyres. One level of index decomposition is performed. The indexes are decomposed into Intensity and Product mix effects. These indexes are tested on a flow shop brick manufacturing plant model in three different climates in the United States. The indexes obtained are analyzed by fitting an ARIMA model and testing for dependency between the two decomposed indexes. Findings and conclusions. The results concluded that the Additive Refined Laspeyres index decomposition methodology is suitable to use on a flow shop, non air conditioned production environment as an energy performance monitoring indicator. It is likely that this research can be further expanded in to predicting when to perform a recommissioning process.

Dark Energy and Structure Formation

International Nuclear Information System (INIS)

Singh, Anupam

2010-01-01

We study the gravitational dynamics of dark energy configurations. We report on the time evolution of the dark energy field configurations as well as the time evolution of the energy density to demonstrate the gravitational collapse of dark energy field configurations. We live in a Universe which is dominated by Dark Energy. According to current estimates about 75% of the Energy Density is in the form of Dark Energy. Thus when we consider gravitational dynamics and Structure Formation we expect Dark Energy to play an important role. The most promising candidate for dark energy is the energy density of fields in curved space-time. It therefore become a pressing need to understand the gravitational dynamics of dark energy field configurations. We develop and describe the formalism to study the gravitational collapse of fields given any general potential for the fields. We apply this formalism to models of dark energy motivated by particle physics considerations. We solve the resulting evolution equations which determine the time evolution of field configurations as well as the dynamics of space-time. Our results show that gravitational collapse of dark energy field configurations occurs and must be considered in any complete picture of our universe.

Inferring Parametric Energy Consumption Functions at Different Software Levels

DEFF Research Database (Denmark)

Liqat, Umer; Georgiou, Kyriakos; Kerrison, Steve

2016-01-01

The static estimation of the energy consumed by program executions is an important challenge, which has applications in program optimization and verification, and is instrumental in energy-aware software development. Our objective is to estimate such energy consumption in the form of functions...... on the input data sizes of programs. We have developed a tool for experimentation with static analysis which infers such energy functions at two levels, the instruction set architecture (ISA) and the intermediate code (LLVM IR) levels, and reflects it upwards to the higher source code level. This required...... the development of a translation from LLVM IR to an intermediate representation and its integration with existing components, a translation from ISA to the same representation, a resource analyzer, an ISA-level energy model, and a mapping from this model to LLVM IR. The approach has been applied to programs...

Analysis on long-term change of energy system structure in Japan considering CO2 emission and domestic demand

International Nuclear Information System (INIS)

Kurokawa, Shingo; Tabe, Yutaka; Chikahisa, Takemi

2011-01-01

Long-term change of energy system structure in Japan was analyzed to investigate the effect of the CO 2 emission reduction level on the reduction cost using MARKAL model. The MARKAL is composed of energy resources, energy supply technologies, energy ultimate demand technologies and energy service demands with them connected by energy carriers. This paper presents analyses investigating the CO 2 reduction cost and the energy structure change until 2050. Here, we focused on the domestic investment to reduce CO 2 emission. It was shown that the CO 2 reduction until 40% level promotes the energy conversion from coal to natural gas and it causes the increase in total cost of the imported fuel. The higher CO 2 reduction, however, increases the domestic investment for low-emission vehicles, photovoltaic power generation and so on, and decreases the overseas investment, although the total CO 2 reduction cost is increased. This contributes to the revitalization of Japanese economy, together with the reduction of overseas investment. (author)

Cultural energy analyses of dairy cattle receiving different concentrate levels

International Nuclear Information System (INIS)

Koknaroglu, Hayati

2010-01-01

Purpose of this study was to conduct cultural energy analyses of dairy cows receiving different levels of concentrate. Data were acquired by conducting a survey on 132 dairy farms selected by the stratified random sampling method. Dairy cattle farms were divided into three groups according to concentrate level and were analyzed. Accordingly concentrate levels were assigned as low (LLC) ( 50%, 44 farms). Cultural energy used for feed for cows was calculated by multiplying each ingredient with corresponding values of ingredients from literature. Transportation energy was also included in the analysis. Total cultural energy expended was highest for LLC (P < 0.05). Cultural energy expended for feed constituted more than half of the total cultural energy and was highest for LLC (P < 0.05). Cultural energy expended per kg milk and per Mcal protein energy was higher for LLC (P < 0.05). Efficiency defined as Mcal input/Mcal output was better for ILC and was worse for LLC (P < 0.05) and HLC was intermediate thus not differing from other groups. Results show that cultural energy use efficiency does not linearly increases as concentrate level increases and increasing concentrate level does not necessarily mean better efficiency. Thus optimum concentrate level not interfering cows performance should be sought for sustainable dairy production.

Full-Dimensional Quantum Calculations of Vibrational Levels of NH4(+) and Isotopomers on An Accurate Ab Initio Potential Energy Surface.

Science.gov (United States)

Yu, Hua-Gen; Han, Huixian; Guo, Hua

2016-04-14

Vibrational energy levels of the ammonium cation (NH4(+)) and its deuterated isotopomers are calculated using a numerically exact kinetic energy operator on a recently developed nine-dimensional permutation invariant semiglobal potential energy surface fitted to a large number of high-level ab initio points. Like CH4, the vibrational levels of NH4(+) and ND4(+) exhibit a polyad structure, characterized by a collective quantum number P = 2(v1 + v3) + v2 + v4. The low-lying vibrational levels of all isotopomers are assigned and the agreement with available experimental data is better than 1 cm(-1).

Enzymatic versus Inorganic Oxygen Reduction Catalysts: Comparison of the Energy Levels in a Free-Energy Scheme

DEFF Research Database (Denmark)

Kjærgaard, Christian Hauge; Rossmeisl, Jan; Nørskov, Jens Kehlet

2010-01-01

In this paper, we present a method to directly compare the energy levels of intermediates in enzymatic and inorganic oxygen reduction catalysts. We initially describe how the energy levels of a Pt(111) catalyst, operating at pH = 0, are obtained. By a simple procedure, we then convert the energy...... levels of cytochrome c oxidase (CcO) models obtained at physiological pH = 7 to the energy levels at pH = 0, which allows for comparison. Furthermore, we illustrate how different bias voltages will affect the free-energy landscapes of the catalysts. This allows us to determine the so-called theoretical...

Excitation-energy-dependent resonances in x-ray emissions under near-threshold electron excitation of the Ce 3d and 4d levels

International Nuclear Information System (INIS)

Chamberlain, M.B.; Baun, W.L.

1975-01-01

Soft x-ray appearance potential spectra of the 3d and 4d levels of polycrystalline cerium metal are reported in this paper. Resonant x-ray emissions are observed when the electron-excitation energy sweeps through the ionization energies of the 3d and 4d levels. The resonant x rays excited at the 3d-level onsets are considerably more intense, and are excited at a lower electron-excitation energy than the 3d-series characteristic x rays. In the neighborhood of the 4d-electron thresholds, four line-like structures extend to approx.8 eV below the 4d-electron binding energies, while two broad and more intense structures occur above the 4d onsets, with the largest one reaching a peak intensity at 12 eV above the 4d thresholds. The resonant emissions apparently arise from the decay of threshold-excited states which are bound to the inner vacancy and have core configurations nd 9 4f 3 , (n=3,4). The exchange interaction between the three 4f electrons and the respective d-orbital vacancy spreads the 4d-threshold structures over a 20 eV range of excitation energies and the 3d-threshold structures over a much smaller range

Structured packing: an opportunity for energy savings

International Nuclear Information System (INIS)

Chavez T, R.H.; Guadarrama G, J.J.

1996-01-01

This work emphasizes the advantages about the use of structured packing. This type of packings allows by its geometry to reduce the processing time giving energy savings and throw down the production costs in several industries such as heavy water production plants, petrochemical industry and all industries involved with separation processes. There is a comparative results of energy consumption utilizing the structured vs. Raschig packings. (Author)

Intelligent structures and design of energy related facilities

International Nuclear Information System (INIS)

Namba, Haruyuki

1994-01-01

Possibility of applying intelligent structural concepts to civil design of energy plants is discussed. Intelligent structures, which are now common in aerospace engineering field, are also referred to as adaptive structures or smart structures depending on cases. Among various existing concepts, reconfigurable structures, precise shape control, structural monitoring using smart materials of optical fiber sensors, and relation with recent innovative communication technologies are focused from civil engineering point of view. Application of such new technologies will help to enhance design of energy related plants, which include multiplex functions which need to be very reliable and safe. (author)

Harvesting Energy from Vibrations of the Underlying Structure

DEFF Research Database (Denmark)

Han, Bo; Vssilaras, S; Papadias, C.B.

2013-01-01

to the long-term structural health of a building or bridge, but at the same time they can be exploited as a power source to power the wireless sensors that are monitoring this structural health. This paper presents a new energy harvesting method based on a vibration driven electromagnetic harvester. By using......The use of wireless sensors for structural health monitoring offers several advantages such as small size, easy installation and minimal intervention on existing structures. However the most significant concern about such wireless sensors is the lifetime of the system, which depends heavily...... on the type of power supply. No matter how energy efficient the operation of a battery operated sensor is, the energy of the battery will be exhausted at some point. In order to achieve a virtually unlimited lifetime, the sensor node should be able to recharge its battery in an easy way. Energy harvesting...

Energy matching and optimization analysis of waste to energy CCHP (combined cooling, heating and power) system with exergy and energy level

International Nuclear Information System (INIS)

Gao, Penghui; Dai, Yanjun; Tong, YenWah; Dong, Pengwei

2015-01-01

CCHP (combined cooling, heating and power) system as a poly-generation technology has received an increasing attention in field of small scale power systems for applications ranging from residence to utilities. It will also play an important role in waste to energy application for megacities. However, how to evaluate and manage energy utilization of CCHP scientifically remains unclear. In this paper, energy level and exergy analysis are implemented on energy conversion processes to reveal the variation of energy amount and quality in the operation of CCHP system. Moreover, based on the energy level analysis, the methodology of energy matching and optimization for the CCHP system is proposed. By this method, the operational parameters of CCHP system can be deduced to obtain an efficient performance and proper energy utilization. It will be beneficial to understand and operate the CCHP system, and to provide a guiding principle of the energy conversion and management for the CCHP system. - Highlights: • Energy level is implemented to reveal the energy variation of CCHP system. • A mathematical energy level analysis model of CCHP system is proposed. • By energy level analysis between supply and demand, optimal zone is obtained. • This study will be useful for energy matching and optimization of CCHP system

Urban structure, energy and planning

DEFF Research Database (Denmark)

Große, Juliane; Fertner, Christian; Groth, Niels Boje

2016-01-01

Transforming energy use in cities to address the threats of climate change and resource scarcity is a major challenge in urban development. This study takes stock of the state of energy in urban policy and planning and reveals potentials of and constraints to energy-efficient urban development....... The relationship between energy and urban structure provides a framework for discussing the role of urban planning to increase energy efficiency in cities by means of three in-depth case studies of medium-sized cities in Northern Europe: Eskilstuna in Sweden, Turku in Finland and Tartu in Estonia. In some ways...... these cities go ahead when it comes to their national climate and energy policies and aim to establish urban planning as an instrument to regulate and influence the city’s transition in a sustainable way. At the same time, the cities are constantly facing goal conflicts and limitations to their scope of action...

Energy-level scheme and transition probabilities of Si-like ions

International Nuclear Information System (INIS)

Huang, K.N.

1984-01-01

Theoretical energy levels and transition probabilities are presented for 27 low-lying levels of silicon-like ions from Z = 15 to Z = 106. The multiconfiguration Dirac-Fock technique is used to calculate energy levels and wave functions. The Breit interaction and Lamb shift contributions are calculated perturbatively as corrections to the Dirac-Fock energy. The M1 and E2 transitions between the first nine levels and the E1 transitions between excited and the ground levels are presented

Application of Foldcore Sandwich Structures in Helicopter Subfloor Energy Absorption Structure

Science.gov (United States)

Zhou, H. Z.; Wang, Z. J.

2017-10-01

The intersection element is an important part of the helicopter subfloor structure. The numerical simulation model of the intersection element is established and the crush simulation is conducted. The simulation results agree well with the experiment results. In order to improve the buffering capacity and energy-absorbing capacity, the intersection element is redesigned. The skin and the floor in the intersection element are replaced with foldcore sandwich structures. The new intersection element is studied using the same simulation method as the typical intersection element. The analysis result shows that foldcore can improve the buffering capacity and the energy-absorbing capacity, and reduce the structure mass.

Occupation number dependence of molecular energy levels

International Nuclear Information System (INIS)

Giambiagi, M.S. de; Giambiagi, M.; Ferreira, R.

1977-08-01

The Roothaan expression for the energy of a closed-shell molecular system is generalized in order to apply to open shells. A continuous variation from 0 to 2 is supposed for each level's occupation number, extending to this range tbe correction due to the spurious repulsion appearing in the half-electron method. The characteristic equations of the Xα method are applied to the energy expressions. The one level case is discussed in detail. Ionic and excited states of the 1,3 transbutadiene π system are analyzed

Non-empirical energy density functional for the nuclear structure

International Nuclear Information System (INIS)

Rot ival, V.

2008-09-01

The energy density functional (EDF) formalism is the tool of choice for large-scale low-energy nuclear structure calculations both for stable experimentally known nuclei whose properties are accurately reproduced and systems that are only theoretically predicted. We highlight in the present dissertation the capability of EDF methods to tackle exotic phenomena appearing at the very limits of stability, that is the formation of nuclear halos. We devise a new quantitative and model-independent method that characterizes the existence and properties of halos in medium- to heavy-mass nuclei, and quantifies the impact of pairing correlations and the choice of the energy functional on the formation of such systems. These results are found to be limited by the predictive power of currently-used EDFs that rely on fitting to known experimental data. In the second part of this dissertation, we initiate the construction of non-empirical EDFs that make use of the new paradigm for vacuum nucleon-nucleon interactions set by so-called low-momentum interactions generated through the application of renormalization group techniques. These soft-core vacuum potentials are used as a step-stone of a long-term strategy which connects modern many-body techniques and EDF methods. We provide guidelines for designing several non-empirical models that include in-medium many-body effects at various levels of approximation, and can be handled in state-of-the art nuclear structure codes. In the present work, the first step is initiated through the adjustment of an operator representation of low-momentum vacuum interactions using a custom-designed parallel evolutionary algorithm. The first results highlight the possibility to grasp most of the relevant physics for low-energy nuclear structure using this numerically convenient Gaussian vertex. (author)

Structural Biology for A-Level Students

Science.gov (United States)

Philip, Judith

2013-01-01

The relationship between the structure and function of proteins is an important area in biochemistry. Pupils studying A-level Biology are introduced to the four levels of protein structure (primary, secondary, tertiary and quaternary) and how these can be used to describe the progressive folding of a chain of amino acid residues to a final,…

High energy physics. Ultimate structure of matter and energy

International Nuclear Information System (INIS)

1979-04-01

Some of the principle discoveries and insights and their development up to today are sketched. It is shown how one layer after another was discovered by penetrating farther into the structure of matter. Covered are the mounting energy scale, discoveries at high energy frontier, the families of quarks and leptons, the four forces of nature, some achievements of the past few years, particle accelerators and experimental apparatus. A glossary of terms is included

Structure of Warm Nuclei

International Nuclear Information System (INIS)

Aaberg, S.; Uhrenholt, H.

2009-01-01

We study the structure of nuclei in the energy region between the ground state and the neutron separation energy, here called warm nuclei. The onset of chaos in the nucleus as excitation energy is increased is briefly reviewed. Chaos implies fluctuations of energies and wave functions qualitatively the same for all chaotic nuclei. On the other hand, large structure effects are seen, e.g. in the level-density function at same excitation energies. A microscopic model for the level density is reviewed and we discuss effects on structure of the total level-density function, parity enhancement, and the spin distribution function. Comparisons to data are performed at the neutron separation energy for all observed nuclei, and structure of the level-density function for a few measured cases. The role of structure effects in the level-density function for fission dynamics is exemplified.

On the structure of critical energy levels for the cubic focusing NLS on star graphs

International Nuclear Information System (INIS)

Adami, Riccardo; Noja, Diego; Cacciapuoti, Claudio; Finco, Domenico

2012-01-01

We provide information on a non-trivial structure of phase space of the cubic nonlinear Schrödinger (NLS) on a three-edge star graph. We prove that, in contrast to the case of the standard NLS on the line, the energy associated with the cubic focusing Schrödinger equation on the three-edge star graph with a free (Kirchhoff) vertex does not attain a minimum value on any sphere of constant L 2 -norm. We moreover show that the only stationary state with prescribed L 2 -norm is indeed a saddle point. (fast track communication)

The application of mass and energy conservation laws in physiologically structured population models of heterotrophic organisms

Science.gov (United States)

Kooijman; Kooi; Hallam

1999-04-07

Rules for energy uptake, and subsequent utilization, form the basis of population dynamics and, therefore, explain the dynamics of the ecosystem structure in terms of changes in standing crops and size distributions of individuals. Mass fluxes are concomitant with energy flows and delineate functional aspects of ecosystems by defining the roles of individuals and populations. The assumption of homeostasis of body components, and an assumption about the general structure of energy budgets, imply that mass fluxes can be written as weighted sums of three organizing energy fluxes with the weight coefficients determined by the conservation law of mass. These energy fluxes are assimilation, maintenance and growth, and provide a theoretical underpinning of the widely applied empirical method of indirect calorimetry, which relates dissipating heat linearly to three mass fluxes: carbon dioxide production, oxygen consumption and N-waste production. A generic approach to the stoichiometry of population energetics from the perspective of the individual organism is proposed and illustrated for heterotrophic organisms. This approach indicates that mass transformations can be identified by accounting for maintenance requirements and overhead costs for the various metabolic processes at the population level. The theoretical background for coupling the dynamics of the structure of communities to nutrient cycles, including the water balance, as well as explicit expressions for the dissipating heat at the population level are obtained based on the conservation law of energy. Specifications of the general theory employ the Dynamic Energy Budget model for individuals. Copyright 1999 Academic Press.

A multi-criteria methodology for energy planning and developing renewable energy sources at a regional level: A case study Thassos, Greece

International Nuclear Information System (INIS)

Mourmouris, J.C.; Potolias, C.

2013-01-01

Rational energy planning under the pressure of environmental and economic problems is imperative to humanity. An evaluational framework is proposed in order to support energy planning for promoting the use of renewable energy sources. A multi-criteria decision analysis is adopted, detailing exploitation of renewable energy sources (including Wind, Solar, Biomass, Geothermal, and small Hydro) for power and heat generation. The aim of this paper is the analysis and development of a multilevel decision-making structure, utilizing multiple criteria for energy planning and exploitation of Renewable Energy Sources of at the regional level. The proposed evaluation framework focuses on the use of a multi-criteria approach as a tool for supporting energy planning in the area of concern, based on a pool of qualitative and quantitative evaluation criteria. The final aim of this study is to discover the optimal amount of each Renewable Energy Source that can be produced in the region and to contribute to an optimal energy mix. In this paper, a case study for the island of Thassos, Greece is analyzed. The results prove that Renewable Energy Sources exploitation at a regional level can satisfy increasing power demands through environmental-friendly energy systems that combine wind power, biomass and PV systems. - Highlights: ► An evaluational framework is proposed in order to support energy planning. ► A multi-criteria decision analysis is adopted, detailing exploitation of RES for power and heat generation. ► The aim is to discover the optimal amount of each RES that can be produced in each region.

Cost-optimal levels for energy performance requirements

DEFF Research Database (Denmark)

Thomsen, Kirsten Engelund; Aggerholm, Søren; Kluttig-Erhorn, Heike

2011-01-01

The CA conducted a study on experiences and challenges for setting cost optimal levels for energy performance requirements. The results were used as input by the EU Commission in their work of establishing the Regulation on a comparative methodology framework for calculating cost optimal levels...... of minimum energy performance requirements. In addition to the summary report released in August 2011, the full detailed report on this study is now also made available, just as the EC is about to publish its proposed Regulation for MS to apply in their process to update national building requirements....

Improving energy consumption structure: A comprehensive assessment of fossil energy subsidies reform in China

International Nuclear Information System (INIS)

Liu Wei; Li Hong

2011-01-01

Fossil energy subsidies reform would be an effective way to improve the energy consumption structure; however, the reform needs to be assessed comprehensively beforehand as it would exert uncertain impacts on economy, society and environment. In this paper, we use price-gap approach to estimate the fossil energy subsidies of China, then establish CGE model that contains pollutant emissions accounts and CO 2 emissions account to stimulate the fossil energy subsidies reform under different scenarios, and the environmental economic analysis concept is introduced to monetize the pollutant reduction benefits. Furthermore, we analyze the possibility and scope of improving the energy consumption structure from the perspective of technical and economic analysis. Analytical results show that the energy consumption structure could be improved by different extent by removing coal or oil subsidies, while the economic and social indexes will be influenced distinctively. Meanwhile, the effects of cutting coal subsidies are more feasible than that of cutting oil subsidies overall. It is recommended to implement fossil energy subsidies gradually, cut the coal first and then cut oil subsidies successively. - Research highlights: → This paper estimates the scale of fossil energy subsidies of China in 2007 with price-gap approach. → We establish a Social Accounting Matrix and a CGE model extended with pollutant accounts. → We simulate the impacts of removing or cutting subsidies under three different scenarios. → We discuss the possibility and potential of improving energy consumption structure.

Frontiers of controlling energy levels at interfaces

Science.gov (United States)

Koch, Norbert

The alignment of electron energy levels at interfaces between semiconductors, dielectrics, and electrodes determines the function and efficiency of all electronic and optoelectronic devices. Reliable guidelines for predicting the level alignment for a given material combination and methods to adjust the intrinsic energy landscape are needed to enable efficient engineering approaches. These are sufficiently understood for established electronic materials, e.g., Si, but for the increasing number of emerging materials, e.g., organic and 2D semiconductors, perovskites, this is work in progress. The intrinsic level alignment and the underlying mechanisms at interfaces between organic and inorganic semiconductors are discussed first. Next, methods to alter the level alignment are introduced, which all base on proper charge density rearrangement at a heterojunction. As interface modification agents we use molecular electron acceptors and donors, as well as molecular photochromic switches that add a dynamic aspect and allow device multifunctionality. For 2D semiconductors surface transfer doping with molecular acceptors/donors transpires as viable method to locally tune the Fermi-level position in the energy gap. The fundamental electronic properties of a prototypical 1D interface between intrinsic and p-doped 2D semiconductor regions are derived from local (scanning probe) and area-averaged (photoemission) spectroscopy experiments. Future research opportunities for attaining unsurpassed interface control through charge density management are discussed.

A broadband electromagnetic energy harvester with a coupled bistable structure

International Nuclear Information System (INIS)

Zhu, D; Beeby, S P

2013-01-01

This paper investigates a broadband electromagnetic energy harvester with a coupled bistable structure. Both analytical model and experimental results showed that the coupled bistable structure requires lower excitation force to trigger bistable operation than conventional bistable structures. A compact electromagnetic vibration energy harvester with a coupled bistable structure was implemented and tested. It was excited under white noise vibrations. Experimental results showed that the coupled bistable energy harvester can achieve bistable operation with lower excitation amplitude and generate more output power than both conventional bistable and linear energy harvesters under white noise excitation

Electronic structure and spectroscopy of nucleic acid bases: Ionization energies, ionization-induced structural changes, and photoelectron spectra

Energy Technology Data Exchange (ETDEWEB)

Bravaya, Ksenia B.; Kostko, Oleg; Dolgikh, Stanislav; Landau, Arie; Ahmed, Musahid; Krylov, Anna I.

2010-08-02

We report high-level ab initio calculations and single-photon ionization mass spectrometry study of ionization of adenine (A), thymine (T), cytosine (C) and guanine (G). For thymine and adenine, only the lowest-energy tautomers were considered, whereas for cytosine and guanine we characterized five lowest-energy tautomeric forms. The first adiabatic and several vertical ionization energies were computed using equation-of-motion coupled-cluster method for ionization potentials with single and double substitutions. Equilibrium structures of the cationic ground states were characterized by DFT with the {omega}B97X-D functional. The ionization-induced geometry changes of the bases are consistent with the shapes of the corresponding molecular orbitals. For the lowest-energy tautomers, the magnitude of the structural relaxation decreases in the following series G > C > A > T, the respective relaxation energies being 0.41, 0.32, 0.25 and 0.20 eV. The computed adiabatic ionization energies (8.13, 8.89, 8.51-8.67 and 7.75-7.87 eV for A,T,C and G, respectively) agree well with the onsets of the photoionization efficiency (PIE) curves (8.20 {+-} 0.05, 8.95 {+-} 0.05, 8.60 {+-} 0.05 and 7.75 {+-} 0.05 eV). Vibrational progressions for the S{sub 0}-D{sub 0} vibronic bands computed within double-harmonic approximation with Duschinsky rotations are compared with previously reported experimental photoelectron spectra.

Malaysia commercial energy flow: status and structure

International Nuclear Information System (INIS)

Ridzuan Abdul Mutalib; Maragatham Kumar; Nik Arlina Nik Ali; Abi Muttaqin Jalal Bayar; Aisya Raihan Abdul Kadir; Muhammed Zulfakar Zolkaffly; Azlinda Aziz; Jamal Khaer Ibrahim

2008-08-01

With further growth of Malaysia economy, future development of the energy sector in Malaysia is vital to ensure targeted growth. Commercial Energy continues to play a major role in ensuring a balanced energy mix for power generation due to a potential increase in energy demand from various sectors, especially the industrial sector. This paper presents the status and structure of Malaysia Commercial Energy Flow, which gives an overview of the flow of all types of energy sources from primary energy supply to final energy use, and also the potential for nuclear power in electricity generation in Malaysia. (Author)

Multi functional roof structures of the energy efficient buildings

Directory of Open Access Journals (Sweden)

Krstić Aleksandra

2006-01-01

Full Text Available Modern architectural concepts, which are based on rational energy consumption of buildings and the use of solar energy as a renewable energy source, give the new and significant role to the roofs that become multifunctional structures. Various energy efficient roof structures and elements, beside the role of protection, provide thermal and electric energy supply, natural ventilation and cooling of a building, natural lighting of the indoor space sunbeam protection, water supply for technical use, thus according to the above mentioned functions, classification and analysis of such roof structures and elements are made in this paper. The search for new architectural values and optimization in total energy balance of a building or the likewise for the urban complex, gave to roofs the role of "climatic membranes". Contemporary roof forms and materials clearly exemplify their multifunctional features. There are numerous possibilities to achieve the new and attractive roof design which broadens to the whole construction. With such inducement, this paper principally analyze the configuration characteristics of the energy efficient roof structures and elements, as well as the visual effects that may be achieved by their application.

New level of structure

International Nuclear Information System (INIS)

Greenberg, O.W.

1985-01-01

In the standard model of matter, ther are five stages of compositeness- molecules, atoms, nuclei, nucleons, and quarks and leptons-but we are beginning to see regularities at the fifth layer that may point to a deeper, sixth level of structure

Atomic energy-level and Grotrian diagrams. Vol. 4

International Nuclear Information System (INIS)

Bashkin, S.; Stoner, J.O. Jr.

1982-01-01

This is the fifth in a series of volumes that present diagrammatically the spectra of atoms and monatomic ions. All observed transitions and all known levels of manganese are included. All wavelengths are given in angstroms in vacuum below 2000 A, in air above 2000 A. Energies of levels are specified in wavenumbers (cm -1 ), kcm -1 (1 X 10 3 cm -1 ), or Mcm -1 (1 X 10 6 cm -1 ). For energies, all experimentally significant figures are included; for wavelengths, we usually include two decimal places (three for the shortest wavelengths). Descriptions of levels are based in most cases upon the largest percentage contributions of elementary coupling arrangements to the levels. In a few instances several different descriptions of the same levels are presented. (Auth.)

27-Level DC–AC inverter with single energy source

International Nuclear Information System (INIS)

Tsang, K.M.; Chan, W.L.

2012-01-01

Highlights: ► This paper reports a novel 27-level DC–AC inverter using only single renewable energy source. ► The efficiency of the inverter is very high. The output waveform is almost sinusoidal. ► The cost is low as the number of power switches required is only 12. - Abstract: A novel design of multilevel DC–AC inverter using only single renewable energy source is presented in this paper. The proposed approach enables multilevel output to be realised by a few cascaded H-bridges and a single energy source. As an illustration, a 27-level inverter has been implemented based on three cascaded H-bridges with a single energy source and two capacitors. Using the proposed novel switching strategy, 27 levels can be realized and the two virtual energy sources can be well regulated. Experimental results are included to demonstrate the effectiveness of the proposed inverter.

Hyperfine structure of the S levels of the muonic helium ion

International Nuclear Information System (INIS)

Martynenko, A. P.

2008-01-01

Corrections of the α 5 and α 6 orders to the energy spectrum of the hyperfine splitting of the 1S and 2S levels of the muonic helium ion are calculated with the inclusion of the electron vacuum polarization effects, nuclear-structure corrections, and recoil effects. The values ΔE hfs (1S) = -1334.56 meV and ΔE hfs (2S) = -166.62 meV obtained for hyperfine splitting values can be considered as reliable estimates for comparison with experimental data. The hyperfine structure interval Δ 12 = 8ΔE hfs (2S) - ΔE hfs (1S) = 1.64 meV can be used to verify QED predictions

Complex photonic structures for energy efficiency

Directory of Open Access Journals (Sweden)

Wiersma D. S.

2013-06-01

Full Text Available Photonic structures are playing an increasingly important role in energy efficiency. In particular, they can help to control the flow of light and improve the optical properties of photovoltaic solar cells. We will explain the physics of light transport in such structures with a special focus on disordered materials.

North Atlantic Energy Structures

Energy Technology Data Exchange (ETDEWEB)

Campbell, S. [North Atlantic Energy Structures Inc., St. John' s, NL (Canada); Derradji, A. [National Research Council of Canada, St. John' s, NL (Canada). Inst. for Ocean Technology

2005-07-01

North Atlantic Energy Structures Inc. is in the process of designing a tidal fence for a site near the Straits of Belle Isle. This presentation provided details of both the design and the location in which the wave energy plant will be installed. Design constraints included a short seasonal work window, and a harsh but pristine environment. Design specifications of the paddlewheels and caissons were presented. The paddlewheel is iceberg and slab ice resistant, and has portals below the wheel axis, a water-free upper chamber, and bi-directional power generation. The planned installation sequence was presented, as well as details of a hydrodynamic simulation examining torque on the turbines in the tidal energy chamber. Results of the study indicated that 20 paddlewheels per caisson provided the equivalent of 12 MW of energy. A tidal fence of 70 to 80 caissons provided the equivalent of 1.2 GW of energy. A slab ice simulation study was outlined, and details of the pumping station, inlet and hydro-generation station were provided. A map of the proposed siting of the tidal fence was presented. It was concluded that financing for the pilot project has been granted. However, further financing for research and development is required. refs., tabs., figs.

Experimental and theoretical studies of the energy level structure of multiply charged many-electron ions

International Nuclear Information System (INIS)

Redfors, A.

1991-01-01

Magnesiumlike and aluminumlike spectra of the elements calcium - germanium have been obtained through the use of laser-produced plasmas (LPP) and a 3 m normal incidence vacuum spectrograph. The spectral analyses were mainly based on isoelectronic regularities. Intermediate ionization stages of cerium (Ce V) and silicon (SI VI) have also been studied. The light sources in these cases were a sliding spark and a modified version of the LPP. The Eagle spectrograph at the National Institute of Standards and Technology, Gaitherburg, Maryland was used to record the cerium spectrum. Ab initio calculations and least-squares fits of the Slater energy parameters to the experimental energy levels are reported for all investigated spectra. Theoretical predictions of oscillator strengths for Y III and Zr III in the region 1150-3200 AA are presented. The oscillator strengths are needed for abundance determinations of Y 2+ and Zr 2+ in chemically peculiar stars, Cp stars. (65 refs.)

Information Geometry, Inference Methods and Chaotic Energy Levels Statistics

OpenAIRE

Cafaro, Carlo

2008-01-01

In this Letter, we propose a novel information-geometric characterization of chaotic (integrable) energy level statistics of a quantum antiferromagnetic Ising spin chain in a tilted (transverse) external magnetic field. Finally, we conjecture our results might find some potential physical applications in quantum energy level statistics.

Impact of a rural solar electrification project on the level and structure of women’s empowerment

Science.gov (United States)

Burney, Jennifer; Alaofè, Halimatou; Naylor, Rosamond; Taren, Douglas

2017-09-01

Although development organizations agree that reliable access to energy and energy services—one of the 17 Sustainable Development Goals—is likely to have profound and perhaps disproportionate impacts on women, few studies have directly empirically estimated the impact of energy access on women’s empowerment. This is a result of both a relative dearth of energy access evaluations in general and a lack of clarity on how to quantify gender impacts of development projects. Here we present an evaluation of the impacts of the Solar Market Garden—a distributed photovoltaic irrigation project—on the level and structure of women’s empowerment in Benin, West Africa. We use a quasi-experimental design (matched-pair villages) to estimate changes in empowerment for project beneficiaries after one year of Solar Market Garden production relative to non-beneficiaries in both treatment and comparison villages (n = 771). To create an empowerment metric, we constructed a set of general questions based on existing theories of empowerment, and then used latent variable analysis to understand the underlying structure of empowerment locally. We repeated this analysis at follow-up to understand whether the structure of empowerment had changed over time, and then measured changes in both the levels and likelihood of empowerment over time. We show that the Solar Market Garden significantly positively impacted women’s empowerment, particularly through the domain of economic independence. In addition to providing rigorous evidence for the impact of a rural renewable energy project on women’s empowerment, our work lays out a methodology that can be used in the future to benchmark the gender impacts of energy projects.

The structure of nuclear states at low, intermediate and high excitation energies

International Nuclear Information System (INIS)

Soloviev, V.G.

1976-01-01

It is shown that within the model based on the quasiparticle-phonon interaction one can obtain the description of few-quasiparticle components of nuclear states at low, intermediate and high excitation energies. For the low-lying states the energy of each level is calculated. The few-quasiparticle components at intermediate and high excitation energies are represented to be averaged in certain energy intervals and their characteri stics are given as the corresponding strength functions. The fragmentation of single-particle states in deformed nuclei is studied. It is shown that in the distribution of the single-particle strength alongside with a large maximum there appear local maxima and the distribution itself has a long tail. The dependence of neutron strength functions on the excitation energy is investigated for the transfer reaction of the type (d,p) and (d,t). The s,- p,- and d-wave neutron strength functions are calculated at the neutron binding energy Bn. A satisfactory agreement with experiment is obtained. The energies and Elambda-strength functions for giant multipole resonances in deformed nuclei are calculated. The energies of giant quadrupole and octupole resonances are calculated. Their widths and fine structure are being studied. It is stated that to study the structure of highly excited states it is necessary to find the values of many-quasiparticle components of the wave functions. The ways of experimental determination of these components based on the study of γ-transitions between highly excited states are discussed

Nonlinear analysis and dynamic structure in the energy market

Science.gov (United States)

Aghababa, Hajar

This research assesses the dynamic structure of the energy sector of the aggregate economy in the context of nonlinear mechanisms. Earlier studies have focused mainly on the price of the energy products when detecting nonlinearities in time series data of the energy market, and there is little mention of the production side of the market. Moreover, there is a lack of exploration about the implication of high dimensionality and time aggregation when analyzing the market's fundamentals. This research will address these gaps by including the quantity side of the market in addition to the price and by systematically incorporating various frequencies for sample sizes in three essays. The goal of this research is to provide an inclusive and exhaustive examination of the dynamics in the energy markets. The first essay begins with the application of statistical techniques, and it incorporates the most well-known univariate tests for nonlinearity with distinct power functions over alternatives and tests different null hypotheses. It utilizes the daily spot price observations on five major products in the energy market. The results suggest that the time series daily spot prices of the energy products are highly nonlinear in their nature. They demonstrate apparent evidence of general nonlinear serial dependence in each individual series, as well as nonlinearity in the first, second, and third moments of the series. The second essay examines the underlying mechanism of crude oil production and identifies the nonlinear structure of the production market by utilizing various monthly time series observations of crude oil production: the U.S. field, Organization of the Petroleum Exporting Countries (OPEC), non-OPEC, and the world production of crude oil. The finding implies that the time series data of the U.S. field, OPEC, and the world production of crude oil exhibit deep nonlinearity in their structure and are generated by nonlinear mechanisms. However, the dynamics of the non

A phase transition in energy-filtered RNA secondary structures

DEFF Research Database (Denmark)

Han, Hillary Siwei; reidys, Christian

2012-01-01

In this paper we study the effect of energy parameters on minimum free energy (mfe) RNA secondary structures. Employing a simplified combinatorial energy model, that is only dependent on the diagram representation and that is not sequence specific, we prove the following dichotomy result. Mfe...... this phase transition from a discrete limit to a central limit distribution and subsequently put our result into the context of quantifying the effect of sparsification of the folding of these respective mfe-structures. We show that the sparsification of realistic mfe-structures leads to a constant time...

Statistical interpretation of low energy nuclear level schemes

Energy Technology Data Exchange (ETDEWEB)

Egidy, T von; Schmidt, H H; Behkami, A N

1988-01-01

Nuclear level schemes and neutron resonance spacings yield information on level densities and level spacing distributions. A total of 75 nuclear level schemes with 1761 levels and known spins and parities was investigated. The A-dependence of level density parameters is discussed. The spacing distributions of levels near the groundstate indicate transitional character between regular and chaotic properties while chaos dominates near the neutron binding energy.

Dietary energy level for optimum productivity and carcass ...

African Journals Online (AJOL)

user

2013-08-05

Aug 5, 2013 ... optimum weights at dietary energy levels of 13.81, 13.23, 13.43 and ... Tadelle & Ogle (2000) reported that energy requirement of ..... The authors would like to acknowledge the National Research Foundation (NRF) and VLIR ...

A CAD model for energy efficient offshore structures for desalination and energy generation

Directory of Open Access Journals (Sweden)

R. Rahul Dev,

2016-09-01

Full Text Available This paper presents a ‘Computer Aided Design (CAD’ model for energy efficient design of offshore structures. In the CAD model preliminary dimensions and geometric details of an offshore structure (i.e. semi-submersible are optimized to achieve a favorable range of motion to reduce the energy consumed by the ‘Dynamic Position System (DPS’. The presented model allows the designer to select the configuration satisfying the user requirements and integration of Computer Aided Design (CAD and Computational Fluid Dynamics (CFD. The integration of CAD with CFD computes a hydrodynamically and energy efficient hull form. Our results show that the implementation of the present model results into an design that can serve the user specified requirements with less cost and energy consumption.

Macro-level integrated renewable energy production schemes for sustainable development

International Nuclear Information System (INIS)

Subhadra, Bobban G.

2011-01-01

The production of renewable clean energy is a prime necessity for the sustainable future existence of our planet. However, because of the resource-intensive nature, and other challenges associated with these new generation renewable energy sources, novel industrial frameworks need to be co-developed. Integrated renewable energy production schemes with foundations on resource sharing, carbon neutrality, energy-efficient design, source reduction, green processing plan, anthropogenic use of waste resources for the production green energy along with the production of raw material for allied food and chemical industries is imperative for the sustainable development of this sector especially in an emission-constrained future industrial scenario. To attain these objectives, the scope of hybrid renewable production systems and integrated renewable energy industrial ecology is briefly described. Further, the principles of Integrated Renewable Energy Park (IREP) approach, an example for macro-level energy production, and its benefits and global applications are also explored. - Research highlights: → Discusses the need for macro-level renewable energy production schemes. → Scope of hybrid and integrated industrial ecology for renewable energy production. → Integrated Renewable Energy Parks (IREPs): A macro-level energy production scheme. → Discusses the principle foundations and global applications of IREPs. → Describes the significance of IREPs in the carbon-neutral future business arena.

Formation of halo-structures in oxygen isotopes through change of occupancy of levels near Fermi surface

International Nuclear Information System (INIS)

Bhattacharya, Rupayan

2000-01-01

Recently a new parametrisation of Skyrme interaction has been formulated in order to study the level inversions of A=9 isobars. The role of occupancy of 2s 1/2 level in determining the halo structures of O, N, C, B and Be nuclei was shown. A thorough investigation on the binding energies, rms charge, neutron and matter distribution and occupation probabilities of levels near the Fermi surface has been done in the present work

The covalence effect of energy levels of ZnS:Mn2+

International Nuclear Information System (INIS)

Dong-Yang, Li; Mao-Lu, Du; Yi, Huang

2013-01-01

The contribution of the different covalence for t 2 and e orbitals must be considered in the investigation of the optical and magnetic properties of the transition metal ion in II–VI and III–V semiconductors. In present paper, two covalent parameters N t and N e associated with t 2 and e orbitals have been adopted to describe the covalence. The energy matrices considering the different covalence for t 2 and e orbitals have been provided for d 5 ions in crystal. These matrices show that the contribution from the Racah parameter A cannot be neglected in calculation of energy-level of d 5 ions in covalent crystal. The calculated results using the matrix show that the energy levels of 4 E and 4 A 1 states split, and the energy-level difference between 4 E and 4 A 1 states increases with increase of the different covalence between t 2 and e orbitals. These energy levels are always degenerate, when the different covalence for t 2 and e orbitals is neglected. By using the energy matrices, the energy-level of ZnS:Mn 2+ has been calculated. The calculated energy levels of ZnS:Mn 2+ are in good agreement with the experiments

the effect of dietary energy and protein levels on the composition

African Journals Online (AJOL)

Zannel

Keywords: Breeding ostriches, nutrition, energy, protein, amino acids, egg ... Yolk is an important nutritional component of the avian egg because .... 3 (energy) x 3 (protein) factorial design with energy and protein levels featuring as main factors. ... No significant interactions were observed between energy and protein levels.

Developing a network-level structural capacity index for structural evaluation of pavements.

Science.gov (United States)

2013-03-01

The objective of this project was to develop a structural index for use in network-level pavement evaluation to facilitate : the inclusion of the pavements structural condition in pavement management applications. The primary goal of network-level...

Net energy levels on the lipid profile of pork

Directory of Open Access Journals (Sweden)

Stephan Alexander da Silva Alencar

2017-09-01

Full Text Available ABSTRACT: This study was conducted to evaluate the effects of net energy levels on the lipid profile of adipose tissue and muscle of swines. A total of 90 animals, with initial weight of 71.94±4.43kg, were used, and distributed in a randomized block design in five net energy levels (2,300, 2,425, 2,550, 2,675, and 2,800Kcal kg-1 feed, with nine replicates and two animals per experimental unit. Lipid profiles of adipose tissue and muscle were analyzed using gas chromatography. Increasing the levels of net energy using soybean oil, improved the lipid profile of adipose tissue and muscle, increased linearly (P<0.05 the concentrations of polyunsaturated fatty acids, especially linoleic and α-linolenic acid, reduced linearly (P<0.05 the monounsaturated and saturated fatty acids and omega 6: omega 3. In adipose tissue was observed linear reduction (P<0.05 of atherogenic and thrombogenic indexes. In conclusion, increasing the level of net energy of the diet using soybean oil improved the lipid profile of adipose tissue and muscle.

Kinetic-energy density functional: Atoms and shell structure

International Nuclear Information System (INIS)

Garcia-Gonzalez, P.; Alvarellos, J.E.; Chacon, E.

1996-01-01

We present a nonlocal kinetic-energy functional which includes an anisotropic average of the density through a symmetrization procedure. This functional allows a better description of the nonlocal effects of the electron system. The main consequence of the symmetrization is the appearance of a clear shell structure in the atomic density profiles, obtained after the minimization of the total energy. Although previous results with some of the nonlocal kinetic functionals have given incipient structures for heavy atoms, only our functional shows a clear shell structure for most of the atoms. The atomic total energies have a good agreement with the exact calculations. Discussion of the chemical potential and the first ionization potential in atoms is included. The functional is also extended to spin-polarized systems. copyright 1996 The American Physical Society

Measuring excess free energies of self-assembled membrane structures.

Science.gov (United States)

Norizoe, Yuki; Daoulas, Kostas Ch; Müller, Marcus

2010-01-01

Using computer simulation of a solvent-free, coarse-grained model for amphiphilic membranes, we study the excess free energy of hourglass-shaped connections (i.e., stalks) between two apposed bilayer membranes. In order to calculate the free energy by simulation in the canonical ensemble, we reversibly transfer two apposed bilayers into a configuration with a stalk in three steps. First, we gradually replace the intermolecular interactions by an external, ordering field. The latter is chosen such that the structure of the non-interacting system in this field closely resembles the structure of the original, interacting system in the absence of the external field. The absence of structural changes along this path suggests that it is reversible; a fact which is confirmed by expanded-ensemble simulations. Second, the external, ordering field is changed as to transform the non-interacting system from the apposed bilayer structure to two-bilayers connected by a stalk. The final external field is chosen such that the structure of the non-interacting system resembles the structure of the stalk in the interacting system without a field. On the third branch of the transformation path, we reversibly replace the external, ordering field by non-bonded interactions. Using expanded-ensemble techniques, the free energy change along this reversible path can be obtained with an accuracy of 10(-3)k(B)T per molecule in the n VT-ensemble. Calculating the chemical potential, we obtain the free energy of a stalk in the grandcanonical ensemble, and employing semi-grandcanonical techniques, we calculate the change of the excess free energy upon altering the molecular architecture. This computational strategy can be applied to compute the free energy of self-assembled phases in lipid and copolymer systems, and the excess free energy of defects or interfaces.

Influence of dense plasma on the energy levels and transition properties in highly charged ions

Science.gov (United States)

Chen, Zhan-Bin; Hu, Hong-Wei; Ma, Kun; Liu, Xiao-Bin; Guo, Xue-Ling; Li, Shuang; Zhu, Bo-Hong; Huang, Lian; Wang, Kai

2018-03-01

The studies of the influence of plasma environments on the level structures and transition properties for highly charged ions are presented. For the relativistic treatment, we implemented the multiconfiguration Dirac-Fock method incorporating the ion sphere (IS) model potential, in which the plasma screening is taken into account as a modified interaction potential between the electron and the nucleus. For the nonrelativistic treatment, analytical solutions of the Schrödinger equation with two types of the IS screened potential are proposed. The Ritz variation method is used with hydrogenic wave function as a trial wave function that contains two unknown variational parameters. Bound energies are derived from an energy equation, and the variational parameters are obtained from the minimisation condition of the expectation value of the energy. Numerical results for hydrogen-like ions in dense plasmas are presented as examples. A detailed analysis of the influence of relativistic effects on the energy levels and transition properties is also reported. Our results are compared with available results in the literature showing a good quantitative agreement.

Behavior of Rydberg atoms at surfaces: energy level shifts and ionization

Energy Technology Data Exchange (ETDEWEB)

Dunning, F.B. E-mail: fbd@rice.edu; Dunham, H.R.; Oubre, C.; Nordlander, P

2003-04-01

The ionization of xenon atoms excited to the extreme red and blue states in high-lying Xe(n) Stark manifolds at a metal surface is investigated. The data show that, despite their very different initial spatial characteristics, the extreme members of a given Stark manifold ionize at similar atom/surface separations. This is explained, with the aid of complex scaling calculations, in terms of the strong perturbations in the energies and structure of the atomic states induced by the presence of the surface which lead to avoided crossings between neighboring levels as the surface is approached.

Behavior of Rydberg atoms at surfaces: energy level shifts and ionization

CERN Document Server

Dunning, F B; Oubre, C D; Nordlander, P

2003-01-01

The ionization of xenon atoms excited to the extreme red and blue states in high-lying Xe(n) Stark manifolds at a metal surface is investigated. The data show that, despite their very different initial spatial characteristics, the extreme members of a given Stark manifold ionize at similar atom/surface separations. This is explained, with the aid of complex scaling calculations, in terms of the strong perturbations in the energies and structure of the atomic states induced by the presence of the surface which lead to avoided crossings between neighboring levels as the surface is approached.

Public budgets for energy RD&D and the effects on energy intensity and pollution levels.

Science.gov (United States)

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.

Energy Level Composite Curves-a new graphical methodology for the integration of energy intensive processes

International Nuclear Information System (INIS)

Anantharaman, Rahul; Abbas, Own Syed; Gundersen, Truls

2006-01-01

Pinch Analysis, Exergy Analysis and Optimization have all been used independently or in combination for the energy integration of process plants. In order to address the issue of energy integration, taking into account composition and pressure effects, the concept of energy level as proposed by [X. Feng, X.X. Zhu, Combining pinch and exergy analysis for process modifications, Appl. Therm. Eng. 17 (1997) 249] has been modified and expanded in this work. We have developed a strategy for energy integration that uses process simulation tools to define the interaction between the various subsystems in the plant and a graphical technique to help the engineer interpret the results of the simulation with physical insights that point towards exploring possible integration schemes to increase energy efficiency. The proposed graphical representation of energy levels of processes is very similar to the Composite Curves of Pinch Analysis-the interpretation of the Energy Level Composite Curves reduces to the Pinch Analysis case when dealing with heat transfer. Other similarities and differences are detailed in this work. Energy integration of a methanol plant is taken as a case study to test the efficacy of this methodology. Potential integration schemes are identified that would have been difficult to visualize without the help of the new graphical representation

Functional materials discovery using energy-structure-function maps.

Science.gov (United States)

Pulido, Angeles; Chen, Linjiang; Kaczorowski, Tomasz; Holden, Daniel; Little, Marc A; Chong, Samantha Y; Slater, Benjamin J; McMahon, David P; Bonillo, Baltasar; Stackhouse, Chloe J; Stephenson, Andrew; Kane, Christopher M; Clowes, Rob; Hasell, Tom; Cooper, Andrew I; Day, Graeme M

2017-03-30

Molecular crystals cannot be designed in the same manner as macroscopic objects, because they do not assemble according to simple, intuitive rules. Their structures result from the balance of many weak interactions, rather than from the strong and predictable bonding patterns found in metal-organic frameworks and covalent organic frameworks. Hence, design strategies that assume a topology or other structural blueprint will often fail. Here we combine computational crystal structure prediction and property prediction to build energy-structure-function maps that describe the possible structures and properties that are available to a candidate molecule. Using these maps, we identify a highly porous solid, which has the lowest density reported for a molecular crystal so far. Both the structure of the crystal and its physical properties, such as methane storage capacity and guest-molecule selectivity, are predicted using the molecular structure as the only input. More generally, energy-structure-function maps could be used to guide the experimental discovery of materials with any target function that can be calculated from predicted crystal structures, such as electronic structure or mechanical properties.

New values for some 4He I 1snl energy levels, ionization energies, and Lamb shifts

International Nuclear Information System (INIS)

Martin, W.C.

1984-01-01

Recent experimental determinations of energy separations within the 1snl term system (n = 2--6) have been used to reevaluate 35 levels. Most of the levels have estimated errors less than 0.001 cm -1 relative to the 2 3 P levels. Addition of accurate theoretical term values (ionization energies) available for several 1snl levels to the corresponding experimental level values gives generally consistent values for the principal ionization energy (E/sub I/). The theoretical energies are further confirmed by the agreement of the weighted average of seven of these E/sub I/ values with a value obtained by fitting Ritz formulas to three accurately determined 1snl series; the suggested new E/sub I/ is 198 310.7745(40) cm -1 on an energy scale fixed by the value 171 135.0000 cm -1 for 2 1 P. Lamb shifts are derived for the 2, 3, 4 3 S 1 , 2 1 S 0 , 2 3 P 1 , and 2 1 P 1 levels as differences between experimental term values obtained with the new E/sub I/ and corresponding calculated term values not including Lamb shifts. The experimental and calculated values for the 1s 2 1 S 0 ground level relative to the present 1snl excited-level system are 0.00 +- 0.15 and 0.073 +- 0.009 cm -1 , respectively, so that a approx.20-fold increase in the experimental accuracy would be required to test the calculated ground-level Lamb shift

Energy Absorption Capacity in Natural Fiber Reinforcement Composites Structures

Directory of Open Access Journals (Sweden)

Elías López-Alba

2018-03-01

Full Text Available The study of natural fiber reinforcement composite structures has focused the attention of the automobile industry due to the new regulation in relation to the recyclability and the reusability of the materials preserving and/or improving the mechanical characteristics. The influence of different parameters on the material behavior of natural fiber reinforced plastic structures has been investigated, showing the potential for transport application in energy absorbing structures. Two different woven fabrics (twill and hopsack made of flax fibers as well as a non-woven mat made of a mixture of hemp and kenaf fibers were employed as reinforcing materials. These reinforcing textiles were impregnated with both HD-PE (high-density polyethylen and PLA (polylactic acid matrix, using a continuous compression molding press. The impregnated semi-finished laminates (so-called organic sheets were thermoformed in a second step to half-tubes that were assembled through vibration-welding process to cylindric crash absorbers. The specimens were loaded by compression to determine the specific energy absorption capacity. Quasi-static test results were compared to dynamic test data obtained on a catapult arrangement. The differences on the specific energies absorption (SEA as a function of different parameters, such as the wall thickness, the weave material type, the reinforced textiles, and the matrix used, depending on the velocity rate application were quantified. In the case of quasi-static analysis it is observed a 20% increment in the SEA value when wove Hopsack fabric reinforcement is employed. No velocity rate influence from the material was observed on the SEA evaluation at higher speeds used to perform the experiments. The influence of the weave configuration (Hopsack seems to be more stable against buckling effects at low loading rates with 10% higher SEA values. An increase of SEA level of up to 72% for PLA matrix was observed when compared with HD

On Low Energy Levels in 185W

International Nuclear Information System (INIS)

Malmskog, S.G.; Hoejeberg, M.; Berg, V.

1969-02-01

Gamma ray spectra in the decay of 185 Ta and 185m W have been studied with Ge (Li) detectors. The 185m W isomeric transition at 131.6 keV is shown to be of E3 multipolarity. A level scheme of 185 W is proposed with the following energy levels (energies in keV, spin and K quantum numbers in brackets): 0 (3/2 - 3/2), 23.5 (1/2 - 1/2), 65.9 (5/2 - 3/2), 93.5 (3/2 - 1/2) (uncertain), 173.9 (7/2 - 3/2), 188.1 (5/2 - 1/2), 197.5 (11/2 + 11/2) , 243.5 (7/2 - 7/2), and 390.8 (9/2 - 7/2)

Study and Optimization of Helicopter Subfloor Energy Absorption Structure with Foldcore Sandwich Structures

Science.gov (United States)

HuaZhi, Zhou; ZhiJin, Wang

2017-11-01

The intersection element is an important part of the helicopter subfloor structure. In order to improve the crashworthiness properties, the floor and the skin of the intersection element are replaced with foldcore sandwich structures. Foldcore is a kind of high-energy absorption structure. Compared with original structure, the new intersection element shows better buffering capacity and energy-absorption capacity. To reduce structure’s mass while maintaining the crashworthiness requirements satisfied, optimization of the intersection element geometric parameters is conducted. An optimization method using NSGA-II and Anisotropic Kriging is used. A significant CPU time saving can be obtained by replacing numerical model with Anisotropic Kriging surrogate model. The operation allows 17.15% reduce of the intersection element mass.

Attached flow structure and streamwise energy spectra in a turbulent boundary layer

Science.gov (United States)

Srinath, S.; Vassilicos, J. C.; Cuvier, C.; Laval, J.-P.; Stanislas, M.; Foucaut, J.-M.

2018-05-01

On the basis of (i) particle image velocimetry data of a turbulent boundary layer with large field of view and good spatial resolution and (ii) a mathematical relation between the energy spectrum and specifically modeled flow structures, we show that the scalings of the streamwise energy spectrum E11(kx) in a wave-number range directly affected by the wall are determined by wall-attached eddies but are not given by the Townsend-Perry attached eddy model's prediction of these spectra, at least at the Reynolds numbers Reτ considered here which are between 103 and 104. Instead, we find E11(kx) ˜kx-1 -p where p varies smoothly with distance to the wall from negative values in the buffer layer to positive values in the inertial layer. The exponent p characterizes the turbulence levels inside wall-attached streaky structures conditional on the length of these structures. A particular consequence is that the skin friction velocity is not sufficient to scale E11(kx) for wave numbers directly affected by the wall.

Energy group structure determination using particle swarm optimization

International Nuclear Information System (INIS)

Yi, Ce; Sjoden, Glenn

2013-01-01

Highlights: ► Particle swarm optimization is applied to determine broad group structure. ► A graph representation of the broad group structure problem is introduced. ► The approach is tested on a fuel-pin model. - Abstract: Multi-group theory is widely applied for the energy domain discretization when solving the Linear Boltzmann Equation. To reduce the computational cost, fine group cross libraries are often down-sampled into broad group cross section libraries. Cross section data collapsing generally involves two steps: Firstly, the broad group structure has to be determined; secondly, a weighting scheme is used to evaluate the broad cross section library based on the fine group cross section data and the broad group structure. A common scheme is to average the fine group cross section weighted by the fine group flux. Cross section collapsing techniques have been intensively researched. However, most studies use a pre-determined group structure, open based on experience, to divide the neutron energy spectrum into thermal, epi-thermal, fast, etc. energy range. In this paper, a swarm intelligence algorithm, particle swarm optimization (PSO), is applied to optimize the broad group structure. A graph representation of the broad group structure determination problem is introduced. And the swarm intelligence algorithm is used to solve the graph model. The effectiveness of the approach is demonstrated using a fuel-pin model

Size-dependent energy levels of InSb quantum dots measured by scanning tunneling spectroscopy.

Science.gov (United States)

Wang, Tuo; Vaxenburg, Roman; Liu, Wenyong; Rupich, Sara M; Lifshitz, Efrat; Efros, Alexander L; Talapin, Dmitri V; Sibener, S J

2015-01-27

The electronic structure of single InSb quantum dots (QDs) with diameters between 3 and 7 nm was investigated using atomic force microscopy (AFM) and scanning tunneling spectroscopy (STS). In this size regime, InSb QDs show strong quantum confinement effects which lead to discrete energy levels on both valence and conduction band states. Decrease of the QD size increases the measured band gap and the spacing between energy levels. Multiplets of equally spaced resonance peaks are observed in the tunneling spectra. There, multiplets originate from degeneracy lifting induced by QD charging. The tunneling spectra of InSb QDs are qualitatively different from those observed in the STS of other III-V materials, for example, InAs QDs, with similar band gap energy. Theoretical calculations suggest the electron tunneling occurs through the states connected with L-valley of InSb QDs rather than through states of the Γ-valley. This observation calls for better understanding of the role of indirect valleys in strongly quantum-confined III-V nanomaterials.

Electron bunch structure in energy recovery linac with high-voltage dc photoelectron gun

Directory of Open Access Journals (Sweden)

Y. M. Saveliev

2016-09-01

Full Text Available The internal structure of electron bunches generated in an injector line with a dc photoelectron gun is investigated. Experiments were conducted on the ALICE (accelerators and lasers in combined experiments energy recovery linac at Daresbury Laboratory. At a relatively low dc gun voltage of 230 kV, the bunch normally consisted of two beamlets with different electron energies, as well as transverse and longitudinal characteristics. The beamlets are formed at the head and the tail of the bunch. At a higher gun voltage of 325 kV, the beam substructure is much less pronounced and could be observed only at nonoptimal injector settings. Experiments and computer simulations demonstrated that the bunch structure develops during the initial beam acceleration in the superconducting rf booster cavity and can be alleviated either by increasing the gun voltage to the highest possible level or by controlling the beam acceleration from the gun voltage in the first accelerating structure.

A gradient structure for reaction–diffusion systems and for energy-drift-diffusion systems

International Nuclear Information System (INIS)

Mielke, Alexander

2011-01-01

In recent years the theory of the Wasserstein metric has opened up new treatments of diffusion equations as gradient systems, where the free energy or entropy take the role of the driving functional and where the space is equipped with the Wasserstein metric. We show on the formal level that this gradient structure can be generalized to reaction–diffusion systems with reversible mass-action kinetic. The metric is constructed using the dual dissipation potential, which is a quadratic functional of all chemical potentials including the mobilities as well as the reaction kinetics. The metric structure is obtained by Legendre transform from the dual dissipation potential. The same ideas extend to systems including electrostatic interactions or a correct energy balance via coupling to the heat equation. We show this by treating the semiconductor equations involving the electron and hole densities, the electrostatic potential, and the temperature. Thus, the models in Albinus et al (2002 Nonlinearity 15 367–83), which stimulated this work, have a gradient structure

Production of Energy Efficient Preform Structures (PEEPS)

Energy Technology Data Exchange (ETDEWEB)

Dr. John A. Baumann

2012-06-08

Due to its low density, good structural characteristics, excellent fabrication properties, and attractive appearance, aluminum metal and its alloys continue to be widely utilized. The transportation industry continues to be the largest consumer of aluminum products, with aerospace as the principal driver for this use. Boeing has long been the largest single company consumer of heat-treated aluminum in the U.S. The extensive use of aluminum to build aircraft and launch vehicles has been sustained, despite the growing reliance on more structurally efficient carbon fiber reinforced composite materials. The trend in the aerospace industry over the past several decades has been to rely extensively on large, complex, thin-walled, monolithic machined structural components, which are fabricated from heavy billets and thick plate using high speed machining. The use of these high buy-to-fly ratio starting product forms, while currently cost effective, is energy inefficient, with a high environmental impact. The widespread implementation of Solid State Joining (SSJ) technologies, to produce lower buy-to-fly ratio starting forms, tailored to each specific application, offers the potential for a more sustainable manufacturing strategy, which would consume less energy, require less material, and reduce material and manufacturing costs. One objective of this project was to project the energy benefits of using SSJ techniques to produce high-performance aluminum structures if implemented in the production of the world fleet of commercial aircraft. A further objective was to produce an energy consumption prediction model, capable of calculating the total energy consumption, solid waste burden, acidification potential, and CO2 burden in producing a starting product form - whether by conventional or SSJ processes - and machining that to a final part configuration. The model needed to be capable of computing and comparing, on an individual part/geometry basis, multiple possible

High energy structures in heavy ion collisions: a multiphonon description

International Nuclear Information System (INIS)

Chomaz, P.; Blumenfeld, Y.; Frascaria, N.

1984-01-01

Energy spectra of fragments from the 36 Ar + 208 Pb reaction at 11 MeV/n exhibit structures at high excitation energies. These structures are interpreted in terms of target multi-phonon excitations built from giant resonances. The importance of such processes for the kinetic energy dissipation in heavy ion collisions is emphasized

Investigation of the energy levels of 38AR

International Nuclear Information System (INIS)

Waanders, F.B.

1975-07-01

In this project information on the energy levels of 38 Ar was obtained by means of the (p,γ) reaction. The 1,1 MeV Cockroft-Walton accelerator of the Potchefstroom University for CHE was used to produce the proton beam while a 80 cm 3 Ge(Li) detector was used to detect the gamma-rays. Precise gamma-branchings were determined for 50 bound levels, of which four have not previously been determined. These branchings were obtained from the 28 resonances studied in the 37 Cl(p,γ) 38 Ar reaction. The resonance with a proton energy of (592 plus minus 3) keV was not detected previously. The resonance energies, Q-value and energies of the bound levels used in this project were taken from the study done by Alderliesten. The mean lifetimes of a few bound levels of 38 Ar were measured by means of the doppler shift attenuation method. The results concerning the bound states and mean lifetimes are in good agreement with previous experiments. Limitations on the spin and parities of 19 (p,γ) resonances have been set by means of Weisskopf estimates. Only those cases for which the spin could be limited to two values are discussed in the text. A summary of experimental data obtained on 38 Ar is compared with the results from shellmodel calculations done by various workers. A short discussion on the analogue states in 38 Ar is also given [af

Impact behaviour of Napier/polyester composites under different energy levels

Energy Technology Data Exchange (ETDEWEB)

Fahmi, I., E-mail: fahmi-unimap@yahoo.com; Majid, M. S. Abdul, E-mail: shukry@unimap.edu.my; Afendi, M., E-mail: afendirojan@unimap.edu.my; Haameem, J. M.A., E-mail: mhaameem@gmail.com [School of Mechatronic Engineering, Universiti Malaysia Perlis, Arau (Malaysia); Haslan, M., E-mail: haslan@sirim.my; Helmi, E. A., E-mail: hilmi@sirim.my [Advanced Material Research Centre (AMREC), SIRIM Berhad, Kulim (Malaysia)

2016-07-19

The effects of different energy levels on the impact behaviour of Napier fibre/polyester reinforced composites were investigated. Napier fibre was extracted using traditional water retting process to be utilized as reinforcing materials in polyester composite laminates. 25% fibre loading composite laminates were prepared and impacted at three different energy levels; 2.5,5 and 7.5 J using an instrumented drop weight impact testing machine (IMATEK IM10). The outcomes show that peak force and contact time increase with increased impact load. The energy absorption was then calculated from the force displacement curve. The results indicated that the energy absorption decreases with increasing energy levels of the impact. Impacted specimens were observed visually for fragmentation fracture using an optical camera to identify the failure mechanisms. Fracture fragmentation pattern from permanent dent to perforation with radial and circumferential was observed.

Comparison of energy performance requirements levels

DEFF Research Database (Denmark)

Spiekman, Marleen; Thomsen, Kirsten Engelund; Rose, Jørgen

This summary report provides a synthesis of the work within the EU SAVE project ASIEPI on developing a method to compare the energy performance (EP) requirement levels among the countries of Europe. Comparing EP requirement levels constitutes a major challenge. From the comparison of for instance...... the present Dutch requirement level (EPC) of 0,8 with the present Flemish level of E80, it can easily be seen that direct comparison is not possible. The conclusions and recommendations of the study are presented in part A. These constitute the most important result of the project. Part B gives an overview...... of all other project material related to that topic, which allows to easily identify the most pertinent information. Part C lists the project partners and sponsors....

A broadband electromagnetic energy harvester with a coupled bistable structure

OpenAIRE

Zhu, Dibin; Beeby, Steve

2013-01-01

This paper investigates a broadband electromagnetic energy harvester with a coupled bistable structure. Both analytical model and experimental results showed that the coupled bistable structure requires lower excitation force to trigger bistable operation than conventional bistable structures. A compact electromagnetic vibration energy harvester with a coupled bistable structure was implemented and tested. It was excited under white noise vibrations. Experimental results showed that the coupl...

National energy peak leveling program (NEPLP). Final report

Energy Technology Data Exchange (ETDEWEB)

None

1977-12-01

This three-volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of the three volume report is a final report appendix with information on the National Energy Peak Leveling Program (NEPLP).

Energy levels and the de Broglie relationship for high school students

Science.gov (United States)

Gianino, Concetto

2008-07-01

In this article, four examples of possible lessons on energy levels for high school are described: a particle in a box, a finite square well, the hydrogen atom and a harmonic oscillator. The energy levels are deduced through the use of the steady-state condition and the de Broglie relationship. In particular, the harmonic oscillator energy levels are deduced using correspondence with circular uniform motion.

The Low-Carbon Transition toward Sustainability of Regional Coal-Dominated Energy Consumption Structure: A Case of Hebei Province in China

Directory of Open Access Journals (Sweden)

Xunmin Ou

2017-07-01

Full Text Available CO2 emission resulted from fossil energy use is threatening human sustainability globally. This study focuses on the low-carbon transition of Hebei’s coal-dominated energy system by estimating its total end-use energy consumption, primary energy supply and resultant CO2 emission up to 2030, by employing an energy demand analysis model based on setting of the economic growth rate, industrial structure, industry/sector energy consumption intensity, energy supply structure, and CO2 emission factor. It is found that the total primary energy consumption in Hebei will be 471 and 431 million tons of coal equivalent (tce in 2030 in our two defined scenarios (conventional development scenario and coordinated development scenario, which are 1.40 and 1.28 times of the level in 2015, respectively. The resultant full-chain CO2 emission will be 1027 and 916 million tons in 2030 in the two scenarios, which are 1.24 and 1.10 times of the level in 2015, respectively. The full-chain CO2 emission will peak in about 2025. It is found that the coal-dominated situation of energy structure and CO2 emission increasing trend in Hebei can be changed in the future in the coordinated development scenario, in which Beijing-Tianjin-Hebei area coordinated development strategy will be strengthened. The energy structure of Hebei can be optimised since the proportion of coal in total primary energy consumption can fall from around 80% in 2015 to below 30% in 2030 and the proportions of transferred electricity, natural gas, nuclear energy and renewable energy can increase rapidly. Some specific additional policy instruments are also suggested to support the low-carbon transition of energy system in Hebei under the framework of the coordinated development of Beijing-Tianjin-Hebei area, and with the support from the central government of China.

Numerical Analysis of a Large Floating Wave Energy Converter with Adjustable Structural Geometry

DEFF Research Database (Denmark)

Ferri, Francesco; Pecher, Arthur Francois Serge; Kofoed, Jens Peter

2015-01-01

by the structural loads in extreme conditions. TheWeptos is a large floating WEC, with multiple absorbers, which has proven to be a serious candidate for the renewable energy market, due to both relevant power performance and reduced cost if compared with other WECs. The scope of this article is to compare two......The current cost of energy (CoE) from wave energy converters (WECs) is still significantly higher than other renewable energy resources, thus the sector has not yet reached a competitive level. WECs have a relative small turnover compared to the high capital cost, which to a large extent is driven...... different configurations of the Weptos machine, using the cost of energy (CoE) as a base of comparison. The numerical results are obtained via a multi-body analysis carried out in frequency domain....

Spectrum and energy levels of kryptonlike ion Nb VI

International Nuclear Information System (INIS)

Reader, J.; Ekberg, J.O.

1993-01-01

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 2 4p 6 , 4s 2 4p 6 , 4s 2 4p 5 4d, 4f, 5s, 5p, 5g, 6s, and 4s4p 6 4d configurations as well as some levels of 4p 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 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 5 5g and 6g configurations

Favorable performance of the DFT methods in predicting the minimum-energy structure of the lowest triplet state of WF4

International Nuclear Information System (INIS)

Gutowski, M.; Univ. of Utah, Salt Lake City, UT

1999-01-01

The tetrahedral structure of the lowest triplet state of the WF 4 complex was examined using different variants of the density functional theory (DFT) and conventional ab initio methods. The low-level, conventional, ab initio methods, such as SCF, MP2, MP3, and CISD, predict the tetrahedral structure to be a minimum, whereas the DFT schemes predict an imaginary frequency for the e vibrational mode. Only after recovering electron correlation effects at the MP4 and higher levels, the conventional electronic structure methods also predict the T d structure to be a second-order stationary point. This is not the correlation but the exchange part of the DFT functionals which is responsible for the discrepancy between the DFT and low-level, conventional, ab initio predictions. The lowering of symmetry to C 2v leads to a minimum on the lowest triplet potential energy surface and the electronic energy difference between the T d and C 2v stationary points amounts to 0.85 and 0.96 kcal/mol at the B3LYP and CCSD(T) levels, respectively

Structural Optimization of Triboelectric Nanogenerator for Harvesting Water Wave Energy.

Science.gov (United States)

Jiang, Tao; Zhang, Li Min; Chen, Xiangyu; Han, Chang Bao; Tang, Wei; Zhang, Chi; Xu, Liang; Wang, Zhong Lin

2015-12-22

Ocean waves are one of the most abundant energy sources on earth, but harvesting such energy is rather challenging due to various limitations of current technologies. Recently, networks formed by triboelectric nanogenerator (TENG) have been proposed as a promising technology for harvesting water wave energy. In this work, a basic unit for the TENG network was studied and optimized, which has a box structure composed of walls made of TENG composed of a wavy-structured Cu-Kapton-Cu film and two FEP thin films, with a metal ball enclosed inside. By combination of the theoretical calculations and experimental studies, the output performances of the TENG unit were investigated for various structural parameters, such as the size, mass, or number of the metal balls. From the viewpoint of theory, the output characteristics of TENG during its collision with the ball were numerically calculated by the finite element method and interpolation method, and there exists an optimum ball size or mass to reach maximized output power and electric energy. Moreover, the theoretical results were well verified by the experimental tests. The present work could provide guidance for structural optimization of wavy-structured TENGs for effectively harvesting water wave energy toward the dream of large-scale blue energy.

Method for fitting crystal field parameters and the energy level fitting for Yb3+ in crystal SC2O3

International Nuclear Information System (INIS)

Qing-Li, Zhang; Kai-Jie, Ning; Jin, Xiao; Li-Hua, Ding; Wen-Long, Zhou; Wen-Peng, Liu; Shao-Tang, Yin; Hai-He, Jiang

2010-01-01

A method to compute the numerical derivative of eigenvalues of parameterized crystal field Hamiltonian matrix is given, based on the numerical derivatives the general iteration methods such as Levenberg–Marquardt, Newton method, and so on, can be used to solve crystal field parameters by fitting to experimental energy levels. With the numerical eigenvalue derivative, a detailed iteration algorithm to compute crystal field parameters by fitting experimental energy levels has also been described. This method is used to compute the crystal parameters of Yb 3+ in Sc 2 O 3 crystal, which is prepared by a co-precipitation method and whose structure was refined by Rietveld method. By fitting on the parameters of a simple overlap model of crystal field, the results show that the new method can fit the crystal field energy splitting with fast convergence and good stability. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Mixing Energy Models in Genetic Algorithms for On-Lattice Protein Structure Prediction

Directory of Open Access Journals (Sweden)

Mahmood A. Rashid

2013-01-01

Full Text Available Protein structure prediction (PSP is computationally a very challenging problem. The challenge largely comes from the fact that the energy function that needs to be minimised in order to obtain the native structure of a given protein is not clearly known. A high resolution 20×20 energy model could better capture the behaviour of the actual energy function than a low resolution energy model such as hydrophobic polar. However, the fine grained details of the high resolution interaction energy matrix are often not very informative for guiding the search. In contrast, a low resolution energy model could effectively bias the search towards certain promising directions. In this paper, we develop a genetic algorithm that mainly uses a high resolution energy model for protein structure evaluation but uses a low resolution HP energy model in focussing the search towards exploring structures that have hydrophobic cores. We experimentally show that this mixing of energy models leads to significant lower energy structures compared to the state-of-the-art results.

TLP Structural Health Monitoring Based on Vibration Signal of Energy Harvesting System

Directory of Open Access Journals (Sweden)

Vahid Jahangiri

Full Text Available Abstract Structural Health Monitoring (SHM of Tension Leg Platform (TLP is very crucial for preventing catastrophic and sudden collapse of the structures. One of the methods of monitoring these structures is implementing SHM sensors. Supplying energy for these sensors for a long period is a challenging problem. So, one of the new methods of supplying energy for SHM, is usage of mechanical energy. In this method, the piezoelectric material is employed to convert the mechanical energy which is resulted from vibration of structure, to electrical energy. The advantage of this method is based on not implementing the battery charging system. Therefore, in this paper, after modeling TLP structure, energy supplying of these sensors with piezoelectric converters is studied. Furthermore, fault diagnosis of these structures in the presence of different uncertainties is proposed by the features of voltage signal, produced from piezoelectric patches and fuzzy classification method. Results show that this method can diagnose faults of the structure with an acceptable success rate.

Realistic level densities in fragment emission at high excitation energies

International Nuclear Information System (INIS)

Mustafa, M.G.; Blann, M.; Ignatyuk, A.V.

1993-01-01

Heavy fragment emission from a 44 100 Ru compound nucleus at 400 and 800 MeV of excitation is analyzed to study the influence of level density models on final yields. An approach is used in which only quasibound shell-model levels are included in calculating level densities. We also test the traditional Fermi gas model for which there is no upper energy limit to the single particle levels. We compare the influence of these two level density models in evaporation calculations of primary fragment excitations, kinetic energies and yields, and on final product yields

Experimental evaluation of inner-vacancy level energies for comparison with theory

International Nuclear Information System (INIS)

Deslattes, R.D.; Kessler, E.G.

1985-01-01

This chapter deals with progress on the theoretical side in calculations of atomic inner-shell energy levels. In reaching what the authors consider to be the best available body of experimental data about inner-shell energy-level differences, three types of input are used: those lines which have been directly measured with high-resolution double-diffraction instruments; those obtained with high-resolution curved-crystal optics relative to gamma-ray standards, and those (low-energy) lines whose wavelength ratios with respect to directly measured X-ray lines have been taken from a very restricted set of earlier measurements. Application of X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), appearance-potential spectroscopy (APS), and X-ray emission spectroscopy (XES) to the problem of energy-level difference determination and single-vacancy energy level determination are described

Energy Levels and Radiative Rates for Transitions in F-like Sc XIII and Ne-like Sc XII and Y XXX

Directory of Open Access Journals (Sweden)

Kanti M. Aggarwal

2018-05-01

Full Text Available Energy levels, radiative rates and lifetimes are reported for F-like Sc XIII and Ne-like Sc XII and Y XXX for which the general-purpose relativistic atomic structure package (GRASP has been adopted. For all three ions, limited data exist in the literature but comparisons have been made wherever possible to assess the accuracy of the calculations. In the present work, the lowest 102, 125 and 139 levels have been considered for the respective ions. Additionally, calculations have also been performed with the flexible atomic code (FAC to (particularly confirm the accuracy of energy levels.

Energy Levels and Radiative Rates for Transitions in F-like Sc XIII and Ne-like Sc XII and Y XXX

Science.gov (United States)

Aggarwal, Kanti

2018-05-01

Energy levels, radiative rates and lifetimes are reported for F-like Sc~XIII and Ne-like Sc~XII and Y~XXX for which the general-purpose relativistic atomic structure package ({\\sc grasp}) has been adopted. For all three ions limited data exist in the literature but comparisons have been made wherever possible to assess the accuracy of the calculations. In the present work the lowest 102, 125 and 139 levels have been considered for the respective ions. Additionally, calculations have also been performed with the flexible atomic code ({\\sc fac}) to (particularly) confirm the accuracy of energy levels.

2.3-MW Medium-Voltage, Three-Level Wind Energy Inverter Applying a Unique Bus Structure and 4.5-kV Si/SiC Hybrid Isolated Power Modules: Preprint

Energy Technology Data Exchange (ETDEWEB)

Erdman, W.; Keller, J.; Grider, D.; VanBrunt, E.

2014-11-01

A high-efficiency, 2.3-MW, medium-voltage, three-level inverter utilizing 4.5-kV Si/SiC (silicon carbide) hybrid modules for wind energy applications is discussed. The inverter addresses recent trends in siting the inverter within the base of multimegawatt turbine towers. A simplified split, three-layer laminated bus structure that maintains low parasitic inductances is introduced along with a low-voltage, high-current test method for determining these inductances. Feed-thru bushings, edge fill methods, and other design features of the laminated bus structure provide voltage isolation that is consistent with the 10.4-kV module isolation levels. Inverter efficiency improvement is a result of the (essential) elimination of the reverse recovery charge present in 4.5-kV Si PIN diodes, which can produce a significant reduction in diode turn-off losses as well as insulated-gate bipolar transistor (IGBT) turn-on losses. The hybrid modules are supplied in industry-standard 140 mm x 130 mm and 190 mm x 130 mm packages to demonstrate direct module substitution into existing inverter designs. A focus on laminated bus/capacitor-bank/module subassembly level switching performance is presented.

Effect of deep levels of radiation-induced defects in silicon γ-irradiated Al-V-n-Si structures characteristics

International Nuclear Information System (INIS)

Buzaneva, E.V.; Vdovichenko, A.D.; Kuznetsov, G.V.; Muntyan, Yu.G.

1985-01-01

The effect of high energy γ-quanta irradiation on the mechanism of current transmission in Al-V-N-Si structures employed in Schottky barrier instruments has been investigated. Before irradiation the structures have been annealed in the nitrogen atmosphere at T=500 deg C. The samples have been γ-irradiated on the side of the metall film at T=20 deg C. The irradiation spectrum is continuous, maximum γ-quanta energy 50 MeV, medium one is 20 MeV. The integral flux of γ-quanta, PHIsub(γ) varied from 10 7 to 10 13 quantum/cm -2 . The volt-ampere and volt-farad characteristics have been measred. It is shown that variation of the main electrophysical characteristics of the Al-V-nSi structures upon γ-irradiation is due to deep levels of radiation defects arising in silicon with the energetic position Esub(c)-E=0.38-0.4 eV and Esub(v)+Esub(2)=0.23-0.25 → β, where Esub(c), Esub(v) are energies for the conduction band bottom and the valence band ceiling. In the 77-293 K temperature range the determining range the determining effect on current mission mechanism in irradiated structures is exerted by resonance electron tunnelling with participation of a level with the Esub(c)-Esub(1)=0.38-0.4 eV

Aligned energy-level design for decreasing operation voltage of tandem white organic light-emitting diodes

International Nuclear Information System (INIS)

Chang, Chih-Hao; Wu, Zih-Jyun; Liang, Yi-Hu; Chang, Yu-Shuo; Chiu, Chuan-Hao; Tai, Cheng-Wei; Chang, Hsin-Hua

2013-01-01

In general, organic light-emitting devices (OLEDs) need to operate at higher current density levels to ensure an ample light flux. However, stressed operation will result in poor performance and limited device lifetime. Recently, a tandem structure has been proposed as a pivotal technique to meet the stringent lighting requirements for OLED commercialization, with a research focus on decreasing the concomitant higher operation voltage. Driving two connected emission units (EMUs) in a tandem structure often requires more than twice the driving voltage for a single EMU. This study investigates bipolar host materials and their effective employment in fabricating tandem white phosphorescent OLEDs (PhOLEDs). In addition, the design of a mechanism to align the energy level between the hole transport layer/emitting layer is shown to effectively mitigate operational voltages. In sharp contrast to devices using a unipolar host material, we demonstrate that the turn-on voltage of blue PhOLEDs could be decreased from 3.8 V to 2.7 V through utilizing a bipolar host. Furthermore, applying the proposed techniques to tandem white PhOLEDs produces a luminance of 10 3 cd/m 2 by a 10.1 V driving voltage. - Highlights: • The matched energy level between the hole transport/emitting layer lowers voltages. • Multiple conduction dopants were used to investigate charge generation layer. • Two-color emitters were used to quantify the charge generation strength

Electron Energy Level Statistics in Graphene Quantum Dots

NARCIS (Netherlands)

De Raedt, H.; Katsnellson, M. I.; Katsnelson, M.I.

2008-01-01

Motivated by recent experimental observations of size quantization of electron energy levels in graphene quantum dots [7] we investigate the level statistics in the simplest tight-binding model for different dot shapes by computer simulation. The results are in a reasonable agreement with the

Energy Finite Element Analysis Developments for Vibration Analysis of Composite Aircraft Structures

Science.gov (United States)

Vlahopoulos, Nickolas; Schiller, Noah H.

2011-01-01

The Energy Finite Element Analysis (EFEA) has been utilized successfully for modeling complex structural-acoustic systems with isotropic structural material properties. In this paper, a formulation for modeling structures made out of composite materials is presented. An approach based on spectral finite element analysis is utilized first for developing the equivalent material properties for the composite material. These equivalent properties are employed in the EFEA governing differential equations for representing the composite materials and deriving the element level matrices. The power transmission characteristics at connections between members made out of non-isotropic composite material are considered for deriving suitable power transmission coefficients at junctions of interconnected members. These coefficients are utilized for computing the joint matrix that is needed to assemble the global system of EFEA equations. The global system of EFEA equations is solved numerically and the vibration levels within the entire system can be computed. The new EFEA formulation for modeling composite laminate structures is validated through comparison to test data collected from a representative composite aircraft fuselage that is made out of a composite outer shell and composite frames and stiffeners. NASA Langley constructed the composite cylinder and conducted the test measurements utilized in this work.

ARRA-Multi-Level Energy Storage and Controls for Large-Scale Wind Energy Integration

Energy Technology Data Exchange (ETDEWEB)

David Wenzhong Gao

2012-09-30

The Project Objective is to design innovative energy storage architecture and associated controls for high wind penetration to increase reliability and market acceptance of wind power. The project goals are to facilitate wind energy integration at different levels by design and control of suitable energy storage systems. The three levels of wind power system are: Balancing Control Center level, Wind Power Plant level, and Wind Power Generator level. Our scopes are to smooth the wind power fluctuation and also ensure adequate battery life. In the new hybrid energy storage system (HESS) design for wind power generation application, the boundary levels of the state of charge of the battery and that of the supercapacitor are used in the control strategy. In the controller, some logic gates are also used to control the operating time durations of the battery. The sizing method is based on the average fluctuation of wind profiles of a specific wind station. The calculated battery size is dependent on the size of the supercapacitor, state of charge of the supercapacitor and battery wear. To accommodate the wind power fluctuation, a hybrid energy storage system (HESS) consisting of battery energy system (BESS) and super-capacitor is adopted in this project. A probability-based power capacity specification approach for the BESS and super-capacitors is proposed. Through this method the capacities of BESS and super-capacitor are properly designed to combine the characteristics of high energy density of BESS and the characteristics of high power density of super-capacitor. It turns out that the super-capacitor within HESS deals with the high power fluctuations, which contributes to the extension of BESS lifetime, and the super-capacitor can handle the peaks in wind power fluctuations without the severe penalty of round trip losses associated with a BESS. The proposed approach has been verified based on the real wind data from an existing wind power plant in Iowa. An

A Source-level Energy Optimization Framework for Mobile Applications

DEFF Research Database (Denmark)

Li, Xueliang; Gallagher, John Patrick

2016-01-01

strategies. The framework also lays a foundation for the code optimization by automatic tools. To the best of our knowledge, our work is the first that achieves this for a high-level language such as Java. In a case study, the experimental evaluation shows that our approach is able to save from 6.4% to 50...... process. The source code is the interface between the developer and hardware resources. In this paper, we propose an energy optimization framework guided by a source code energy model that allows developers to be aware of energy usage induced by the code and to apply very targeted source-level refactoring...

Dark energy with a gradient coupling to the dark matter fluid: cosmological dynamics and structure formation

Science.gov (United States)

Dutta, Jibitesh; Khyllep, Wompherdeiki; Tamanini, Nicola

2018-01-01

We consider scalar field models of dark energy interacting with dark matter through a coupling proportional to the contraction of the four-derivative of the scalar field with the four-velocity of the dark matter fluid. The coupling is realized at the Lagrangian level employing the formalism of Scalar-Fluid theories, which use a consistent Lagrangian approach for relativistic fluid to describe dark matter. This framework produces fully covariant field equations, from which we can derive unequivocal cosmological equations at both background and linear perturbations levels. The background evolution is analyzed in detail applying dynamical systems techniques, which allow us to find the complete asymptotic behavior of the universe given any set of model parameters and initial conditions. Furthermore we study linear cosmological perturbations investigating the growth of cosmic structures within the quasi-static approximation. We find that these interacting dark energy models give rise to interesting phenomenological dynamics, including late-time transitions from dark matter to dark energy domination, matter and accelerated scaling solutions and dynamical crossing of the phantom barrier. Moreover we obtain possible deviations from standard ΛCDM behavior at the linear perturbations level, which have an impact on the dynamics of structure formation and might provide characteristic observational signatures.

Relativistic MR–MP Energy Levels for L-shell Ions of Silicon

Science.gov (United States)

Santana, Juan A.; Lopez-Dauphin, Nahyr A.; Beiersdorfer, Peter

2018-01-01

Level energies are reported for Si V, Si VI, Si VII, Si VIII, Si IX, Si X, Si XI, and Si XII. The energies have been calculated with the relativistic Multi-Reference Møller–Plesset Perturbation Theory method and include valence and K-vacancy states with nl up to 5f. The accuracy of the calculated level energies is established by comparison with the recommended data listed in the National Institute of Standards and Technology (NIST) online database. The average deviation of valence level energies ranges from 0.20 eV in Si V to 0.04 eV in Si XII. For K-vacancy states, the available values recommended in the NIST database are limited to Si XII and Si XIII. The average energy deviation is below 0.3 eV for K-vacancy states. The extensive and accurate data set presented here greatly augments the amount of available reference level energies. We expect our data to ease the line identification of L-shell ions of Si in celestial sources and laboratory-generated plasmas, and to serve as energy references in the absence of more accurate laboratory measurements.

Levelized cost of electricity (LCOE) of renewable energies and required subsidies in China

International Nuclear Information System (INIS)

Ouyang, Xiaoling; Lin, Boqiang

2014-01-01

The development and utilization of renewable energy (RE), a strategic choice for energy structural adjustment, is an important measure of carbon emissions reduction in China. High cost is a main restriction element for large-scale development of RE, and accurate cost estimation of renewable power generation is urgently necessary. This is the first systemic study on the levelized cost of electricity (LCOE) of RE in China. Results indicate that feed-in-tariff (FIT) of RE should be improved and dynamically adjusted based on the LCOE to provide a better support of the development of RE. The current FIT in China can only cover the LCOE of wind (onshore) and solar photovoltaic energy (PV) at a discount rate of 5%. Subsidies to renewables-based electricity generation, except biomass energy, still need to be increased at higher discount rates. Main conclusions are drawn as follows: (1) Government policy should focus on solving the financing problem of RE projects because fixed capital investment exerts considerable influence over the LCOE; and (2) the problem of high cost could be solved by providing subsidies in the short term and more importantly, by reforming electricity price in the mid-and long-term to make the RE competitive. - Highlights: • Levelized cost of electricity (LCOE) of renewable energies is systemically studied. • Renewable power generation costs are estimated based on data of 17 power plants. • Required subsidies for renewable power generation are calculated. • Electricity price reform is the long-term strategy for solving problem of high cost

Structural dependence of the 5d-metal surface energies as deduced from surface core-level shift measurements

International Nuclear Information System (INIS)

Mrartensson, N.; Saalfeld, H.B.; Kuhlenbeck, H.; Neumann, M.

1989-01-01

Surface core-level shift measurements performed at the BESSY storage ring yield -0.41(2) eV for Os(0001) and 0.00(10) eV for Re(0001). An analysis of the surface shifts in the 5d transition series shows that the surface energy as a function of Z has a maximum at lower Z for the bcc phase than for the fcc-hcp phases, at W and between Re and Os, respectively

Bistable minimum energy structures (BiMES) for binary robotics

International Nuclear Information System (INIS)

Follador, M; Conn, A T; Rossiter, J

2015-01-01

Bistable minimum energy structures (BiMES) are devices derived from the union of the concepts of dielectric elastomer minimum energy structures and bistable systems. This article presents this novel approach to active, elastic and bistable structures. BiMES are based on dielectric elastomer actuators (DEAs), which act as antagonists and provide the actuation for switching between the two equilibrium positions. A central elastic beam is the backbone of the structure and is buckled into the minimum energy configurations by the action of the two DEAs. The theory and the model of the device are presented, and also its fabrication process. BiMES are considered as fundamental units for more complex structures, which are presented and fabricated as proof of concept. Two different ways of combining the multiple units are proposed: a parallel configuration, to make a simple gripper, and a serial configuration, to generate a binary device. The possibility of using the bistable system as a continuous bender actuator, by modulating the actuation voltage of the two DEAs, was also investigated. (paper)

Risk-based Optimization and Reliability Levels of Coastal Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Burcharth, H. F.

Identification of optimum reliability levels for coastal structures is considered. A class of breakwaters is considered where no human injuries can be expected in cases of failure. The optimum reliability level is identified by minimizing the total costs over the service life of the structure, in...... on the minimumcost reliability levels is investigated for different values of the real rate of interest, the service lifetime, the downtime costs due to malfunction and the decommission costs.......Identification of optimum reliability levels for coastal structures is considered. A class of breakwaters is considered where no human injuries can be expected in cases of failure. The optimum reliability level is identified by minimizing the total costs over the service life of the structure...

Risk-based Optimization and Reliability Levels of Coastal Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Burcharth, Hans F.

2005-01-01

 Identification of optimum reliability levels for coastal structures is considered. A class of breakwaters is considered where no human injuries can be expected in cases of failure. The optimum reliability level is identified by minimizing the total costs over the service life of the structure, i...... on the minimumcost reliability levels is investigated for different values of the real rate of interest, the service lifetime, the downtime costs due to malfunction and the decommission costs....... Identification of optimum reliability levels for coastal structures is considered. A class of breakwaters is considered where no human injuries can be expected in cases of failure. The optimum reliability level is identified by minimizing the total costs over the service life of the structure...

Clean Energy Policy Analyses: Analysis of the Status and Impact of Clean Energy Policies at the Local Level

Energy Technology Data Exchange (ETDEWEB)

Busche, S.

2010-12-01

This report takes a broad look at the status of local clean energy policies in the United States to develop a better understanding of local clean energy policy development and the interaction between state and local policies. To date, the majority of clean energy policy research focuses on the state and federal levels. While there has been a substantial amount of research on local level climate change initiatives, this is one of the first analyses of clean energy policies separate from climate change initiatives. This report is one in a suite of reports analyzing clean energy and climate policy development at the local, state, and regional levels.

Clean Energy Policy Analyses. Analysis of the Status and Impact of Clean Energy Policies at the Local Level

Energy Technology Data Exchange (ETDEWEB)

Busche, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2010-12-01

This report takes a broad look at the status of local clean energy policies in the United States to develop a better understanding of local clean energy policy development and the interaction between state and local policies. To date, the majority of clean energy policy research focuses on the state and federal levels. While there has been a substantial amount of research on local level climate change initiatives, this is one of the first analyses of clean energy policies separate from climate change initiatives. This report is one in a suite of reports analyzing clean energy and climate policy development at the local, state, and regional levels.

The crack energy absorptive capacity of composites with fractal structure

International Nuclear Information System (INIS)

Lung, C.W.

1990-11-01

This paper discusses the energy absorptive capacity of composites with fibers of fractal structures. It is found that this kind of structure may increase the absorption energy during the crack propagation and hence the fracture toughness of composites. (author). 10 refs, 6 figs, 2 tabs

Ab initio study on stacking sequences, free energy, dynamical stability and potential energy surfaces of graphite structures

International Nuclear Information System (INIS)

Anees, P; Valsakumar, M C; Chandra, Sharat; Panigrahi, B K

2014-01-01

Ab initio simulations have been performed to study the structure, energetics and stability of several plausible stacking sequences in graphite. These calculations suggest that in addition to the standard structures, graphite can also exist in AA-simple hexagonal, AB-orthorhombic and ABC-hexagonal type stacking. The free energy difference between these structures is very small (∼1 meV/atom), and hence all the structures can coexist from purely energetic considerations. Calculated x-ray diffraction patterns are similar to those of the standard structures for 2θ ⩽ 70°. Shear elastic constant C 44 is negative in AA-simple hexagonal, AB-orthorhombic and ABC-hexagonal structures, suggesting that these structures are mechanically unstable. Phonon dispersions show that the frequencies of some modes along the Γ–A direction in the Brillouin zone are imaginary in all of the new structures, implying that these structures are dynamically unstable. Incorporation of zero point vibrational energy via the quasi-harmonic approximation does not result in the restoration of dynamical stability. Potential energy surfaces for the unstable normal modes are seen to have the topography of a potential hill for all the new structures, confirming that all of the new structures are inherently unstable. The fact that the potential energy surface is not in the form of a double well implies that the structures are linearly as well as globally unstable. (paper)

Interaction energies and structures of the Li·(CO) n (n= 1–3 ...

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences; Volume 129; Issue 5. Interaction energies ... JAMAL N DAWOUD. Regular Article Volume 129 Issue 5 May 2017 pp 543-552 ... Abstract. The bonding and structures of lithium ion carbonyl complexes, Li⁺·(CO)1−3, were studied at the CCSD and MP2 levels of theories. A linear ...

KEY ASPECTS OF ENSURING ENERGY EFFICIENCY OF BUILDINGS AND STRUCTURES

Directory of Open Access Journals (Sweden)

S.G. Abramyan

2017-06-01

Full Text Available The paper is based on the review of the foreign and national academic literature and intended to emphasize the issues of ensuring energy efficiency of buildings and structures applicable to all the countries as for reconstruction of existing buildings as for erection of new ones . The author highlights the key aspects of the provision of energy efficiency of buildings and structures in some foreign countries. The conclusion is made that the studies are mainly aimed at discovering new heat insulation materials, whereby polystyrene insulation is found to be the most widespread wall insulation material in a number of countries. At the same time, it is observed that the ongoing research is focused on solutions to optimize the structure of walling systems in terms of both insulant thickness and the number and sequence of insulation layers in the walling structure. A conclusion is made that hyper insulation of external walls leads to considerable expenses arising due to cooling during the summer season. The use of prefabricated vacuum panels as a heat insulation layer and off-the-shelf single-layer structures, subject to their heat insulation characteristics, appears a more constructive way to meet the energy efficiency requirements, as the arrangement of ideal air space in multilayered walls proves a significant challenge today. One of the most promising ways to ensure energy efficiency is the use of multifunctional polyvalent walls and provision of polyvalent heat supply from renewable energy sources. Since energy efficiency depends on the spatial arrangement of buildings, construction must ensure a minimum ratio of the area of enclosing structures to the overall building volume (by adding on new facilities in case of reconstruction. It is noted that a systemic approach to ensuring energy efficiency of buildings is impossible without proper regard to the environmental parameters of heat insulation materials.

Impact of Financial Structure on the Cost of Solar Energy

Energy Technology Data Exchange (ETDEWEB)

Mendelsohn, M.; Kreycik, C.; Bird, L.; Schwabe, P.; Cory, K.

2012-03-01

To stimulate investment in renewable energy generation projects, the federal government developed a series of support structures that reduce taxes for eligible investors--the investment tax credit, the production tax credit, and accelerated depreciation. The nature of these tax incentives often requires an outside investor and a complex financial arrangement to allocate risk and reward among the parties. These financial arrangements are generally categorized as 'advanced financial structures.' Among renewable energy technologies, advanced financial structures were first widely deployed by the wind industry and are now being explored by the solar industry to support significant scale-up in project development. This report describes four of the most prevalent financial structures used by the renewable sector and evaluates the impact of financial structure on energy costs for utility-scale solar projects that use photovoltaic and concentrating solar power technologies.

Spin energy levels in axial symmetry: spin 4

Energy Technology Data Exchange (ETDEWEB)

de Biasi, R S; Portella, P D [Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Secao de Engenharia e Ciencia dos Materiais

1979-01-01

The spin energy levels in axial symmetry are presented, in graphical and tabular form, for a spin 4. The levels are calculated for five different angles between the applied field and the symmetry axis 0/sup 0/, 30/sup 0/, 45/sup 0/, 60 and 90/sup 0/.

Energy Dissipation in Sandwich Structures During Axial Compression

DEFF Research Database (Denmark)

Urban, Jesper

2002-01-01

The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full-scale structu......The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full...

Energy conservation in China: Key provincial sectors at two-digit level

International Nuclear Information System (INIS)

Liao, Hua; Du, Jian; Wei, Yi-Ming

2013-01-01

Highlights: ► We identify the keys for energy conversation across China’s 31 provinces × 65 sectors. ► The results are visualized in map and matrix tables, and easy for use. ► 39 Industrial sectors by province are classified into three categories for conservation. ► There is large energy wasting in the public management sector. ► There are both urban–rural gap and provincial inequality on electricity consumption. - Abstract: In March 2011, China’s central government set a new challenging target of reducing its energy intensity by 16% during 2011–2015, after it had achieved a reduction of 19.1% during 2006–2010. And this new target was assigned to provincial authorities in August 2011. However, China’s provincial energy-economic developments are unbalanced and different provinces have different key sectors for energy conservation. Most previous studies focused on provincial energy efficiency at the aggregate level, or the three-industry level (or one-digit level). However, whether for policy decision or academic research, it is necessary to further subdivide the sectors. In this paper, we use three indicators (Gini Coefficient, energy consumption share and energy intensity) to compare provincial energy conservation potentials at the two-digit sector level. To our knowledge, this paper is the first one to identify the keys for energy conversation across the 31 provinces × 65 sectors. And the results are shown in visualized maps and matrix tables to help identify the key province × sectors for energy conservation easier. This also helps the central and provincial governments to distinguish key sectors when they monitor the energy conservation progress

Effect of temperature-dependent energy-level shifts on a semiconductor's Peltier heat

International Nuclear Information System (INIS)

Emin, D.

1984-01-01

The Peltier heat of a charge carrier in a semiconductor is calculated for the situation in which the electronic energy levels are temperature dependent. The temperature dependences of the electronic energy levels, generally observed optically, arise from their dependences on the vibrational energy of the lattice (e.g., as caused by thermal expansion). It has been suggested that these temperature dependences will typically have a major effect on the Peltier heat. The Peltier heat associated with a given energy level is a thermodynamic quantity; it is the product of the temperature and the change of the entropy of the system when a carrier is added in that level. As such, the energy levels cannot be treated as explicitly temperature dependent. The electron-lattice interaction causing the temperature dependence must be expressly considered. It is found that the carrier's interaction with the atomic vibrations lowers its electronic energy. However, the interaction of the carrier with the atomic vibrations also causes an infinitesimal lowering (approx.1/N) of each of the N vibrational frequencies. As a result, there is a finite carrier-induced increase in the average vibrational energy. Above the Debye temperature, this cancels the lowering of the carrier's electronic energy. Thus, the standard Peltier-heat formula, whose derivation generally ignores the temperature dependence of the electronic energy levels, is regained. This explains the apparent success of the standard formula in numerous analyses of electronic transport experiments

Ground level enhancement (GLE) energy spectrum parameters model

Science.gov (United States)

Qin, G.; Wu, S.

2017-12-01

We study the ground level enhancement (GLE) events in solar cycle 23 with the four energy spectra parameters, the normalization parameter C, low-energy power-law slope γ 1, high-energy power-law slope γ 2, and break energy E0, obtained by Mewaldt et al. 2012 who fit the observations to the double power-law equation. we divide the GLEs into two groups, one with strong acceleration by interplanetary (IP) shocks and another one without strong acceleration according to the condition of solar eruptions. We next fit the four parameters with solar event conditions to get models of the parameters for the two groups of GLEs separately. So that we would establish a model of energy spectrum for GLEs for the future space weather prediction.

Spectrum and energy levels of five-times ionized zirconium (Zr VI)

Science.gov (United States)

Reader, Joseph; Lindsay, Mark D.

2016-02-01

We carried out a new analysis of the spectrum of five-times-ionized zirconium Zr VI. For this we used sliding-spark discharges together with normal- and grazing-incidence spectrographs to observe the spectrum from 160 to 2000 Å. These observations showed that the analysis of this spectrum by Khan et al (1985 Phys. Scr. 31 837) contained a significant number of incorrect energy levels. We have now classified ˜420 lines as transitions between 23 even-parity levels 73 odd-parity levels. The 4s24p5, 4s4p6, 4s24p44d, 5s, 5d, 6s configurations are now complete, although a few levels of 4s24p45d are tentative. We determined Ritz-type wavelengths for ˜135 lines from the optimized energy levels. The uncertainties range from 0.0003 to 0.0020 Å. Hartree-Fock calculations and least-squares fits of the energy parameters to the observed levels were used to interpret the observed configurations. Oscillator strengths for all classified lines were calculated with the fitted parameters. The results are compared with values for the level energies, percentage compositions, and transition probabilities from recent ab initio theoretical calculations. The ionization energy was revised to 777 380 ± 300 cm-1 (96.38 ± 0.04 eV).

Free energy minimization to predict RNA secondary structures and computational RNA design.

Science.gov (United States)

Churkin, Alexander; Weinbrand, Lina; Barash, Danny

2015-01-01

Determining the RNA secondary structure from sequence data by computational predictions is a long-standing problem. Its solution has been approached in two distinctive ways. If a multiple sequence alignment of a collection of homologous sequences is available, the comparative method uses phylogeny to determine conserved base pairs that are more likely to form as a result of billions of years of evolution than by chance. In the case of single sequences, recursive algorithms that compute free energy structures by using empirically derived energy parameters have been developed. This latter approach of RNA folding prediction by energy minimization is widely used to predict RNA secondary structure from sequence. For a significant number of RNA molecules, the secondary structure of the RNA molecule is indicative of its function and its computational prediction by minimizing its free energy is important for its functional analysis. A general method for free energy minimization to predict RNA secondary structures is dynamic programming, although other optimization methods have been developed as well along with empirically derived energy parameters. In this chapter, we introduce and illustrate by examples the approach of free energy minimization to predict RNA secondary structures.

Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: Optimization of energy level viewing significantly increases lesion contrast

International Nuclear Information System (INIS)

Patel, B.N.; Thomas, J.V.; Lockhart, M.E.; Berland, L.L.; Morgan, D.E.

2013-01-01

Aim: To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. Materials and methods: The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Results: Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40–77). The mean ± SD lesion contrast values (non-tumoural pancreas – tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 ke

How to Draw Energy Level Diagrams in Excitonic Solar Cells.

Science.gov (United States)

Zhu, X-Y

2014-07-03

Emerging photovoltaic devices based on molecular and nanomaterials are mostly excitonic in nature. The initial absorption of a photon in these materials creates an exciton that can subsequently dissociate in each material or at their interfaces to give charge carriers. Any attempt at mechanistic understanding of excitonic solar cells must start with drawing energy level diagrams. This seemingly elementary exercise, which is described in textbooks for inorganic solar cells, has turned out to be a difficult subject in the literature. The problem stems from conceptual confusion of single-particle energy with quasi-particle energy and the misleading practice of mixing the two on the same energy level diagram. Here, I discuss how to draw physically accurate energy diagrams in excitonic solar cells using only single-particle energies (ionization potentials and electron affinities) of both ground and optically excited states. I will briefly discuss current understanding on the electronic energy landscape responsible for efficient charge separation in excitonic solar cells.

Energy levels of germanium, Ge I through Ge XXXII

International Nuclear Information System (INIS)

Sugar, J.; Musgrove, A.

1993-01-01

Atomic energy levels of germanium have been compiled for all stages of ionization for which experimental data are available. No data have yet been published for Ge VIII through Ge XIII and Ge XXXII. Very accurate calculated values are compiled for Ge XXXI and XXXII. Experimental g-factors and leading percentages from calculated eigenvectors of levels are given. A value for the ionization energy, either experimental when available or theoretical, is included for the neutral atom and each ion. section

Citizen awareness level of the peaceful uses of atomic energy

International Nuclear Information System (INIS)

Elfawairs, Kh.; Elammari, M.

2015-01-01

This paper aims to know the level of public awareness of different types of people, about the peaceful application of nuclear energy. A questionnaire about this subject was distributed randomly in different cities in Libya; the questionnaire was targeting males and females with different educational levels. From data obtained and which was analyzed statistically comparing the educational level with the level of awareness. It was found that the highest contribution was for those holding university degrees 43%. Data analysis showed that 50.5% of the total number do not know what is meant by the peaceful uses of atomic energy and this significantly related to the educational level at significance level ∝=0.01. Concerning the assessment of environmental awareness of the Libyan citizens, 83.3% said that it is weak and the relation is not signification. Concerning the best ways of making people more aware of atomic energy and its peaceful uses 63.9% said all possible means should be used and 21.3% said practical application is the best way, where 13.9% said that they don't know. About the uses of nuclear technology in different fields, the participants had different views. From this study it was concluded that a%. Warnaco programs concerning the peaceful uses of atomic energy should be intensified.(author)

Fine structure and energy spectrum of exciton in direct band gap cubic semiconductors with degenerate valence bands

International Nuclear Information System (INIS)

Nguyen Toan Thang; Nguyen Ai Viet; Nguyen Que Huong

1987-06-01

The influence of the cubic structure on the energy spectrum of direct exciton is investigated, using the new method suggested by Nguyen Van Hieu and co-workers. Explicit expressions of the exciton energy levels 1S, 2S and 2P are derived. A comparison with the experiments and the other theory is done for ZnSe. (author). 10 refs, 1 fig., 2 tabs

A Review of Structure Construction of Silk Fibroin Biomaterials from Single Structures to Multi-Level Structures

Directory of Open Access Journals (Sweden)

Yu Qi

2017-03-01

Full Text Available The biological performance of artificial biomaterials is closely related to their structure characteristics. Cell adhesion, migration, proliferation, and differentiation are all strongly affected by the different scale structures of biomaterials. Silk fibroin (SF, extracted mainly from silkworms, has become a popular biomaterial due to its excellent biocompatibility, exceptional mechanical properties, tunable degradation, ease of processing, and sufficient supply. As a material with excellent processability, SF can be processed into various forms with different structures, including particulate, fiber, film, and three-dimensional (3D porous scaffolds. This review discusses and summarizes the various constructions of SF-based materials, from single structures to multi-level structures, and their applications. In combination with single structures, new techniques for creating special multi-level structures of SF-based materials, such as micropatterning and 3D-printing, are also briefly addressed.

Estimating Solar Energy Potential in Buildings on a Global Level

DEFF Research Database (Denmark)

Petrichenko, Ksenia

2015-01-01

This chapter contributes to the debate around net-zero energy concept from a global perspective. By means of comprehensive modelling, it analyses how much global building energy consumption could be reduced through utilisation of building-integrated solar energy technologies and energy......-efficiency improvements. Valuable insights on the locations and building types, in which it is feasible to achieve a net-zero level of energy performance through solar energy utilisation, are presented in world maps....

Energy balance of lactating primiparous sows as affected by feeding level and dietary energy source

OpenAIRE

Brand, van den, H.; Heetkamp, M.J.W.; Soede, N.M.; Schrama, J.W.; Kemp, B.

2000-01-01

The effects of feeding level and major dietary energy source used during lactation on sow milk composition, piglet body composition, and energy balance of sows were determined. During a 21-d lactation, 48 primiparous sows were fed either a Fat-rich (134.9 g/kg fat; 196.8 g/kg carbohydrate) or a Starch-rich (33.2 g/kg fat; 380.9 g/kg carbohydrate) diet at either a High (44 MJ NE/d; 1,050 g protein/d) or a Low (33 MJ NE/d; 790 g protein/d) feeding level. Within each feeding level, the two diets...

Photoemission spectroscopy study on interfacial energy level alignments in tandem organic light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Ou, Qing-Dong; Li, Chi; Li, Yan-Qing, E-mail: yqli@suda.edu.cn; Tang, Jian-Xin, E-mail: jxtang@suda.edu.cn

2015-10-01

Highlights: • The interface energetics of tandem OLEDs is overviewed. • Energy level alignment in CGLs is addressed via photoemission spectroscopy. • The n-type doping effect with cesium compounds is discussed. • Hole injection barrier is dependent on oxygen vacancies in transition metal oxides. • Device lifetime of tandem OLEDs is sensitive to interfacial stability of CGLs. - Abstract: Organic light-emitting diodes (OLEDs) using a tandem structure offer a highly attractive option for the applications of next-generation flat panel displays and solid-state lighting due to the extremely high brightness and efficiency along with the long operational lifetime. In general, reliable information about interface energetics of the charge generation layers (CGLs), which plays the central role in charge generation and carrier injection into the stacked emission units, is highly desirable and advantageous for interface engineering and the performance optimization of tandem OLEDs. In this review, our recent studies on tandem OLEDs are overviewed, especially from interface energetics perspective via photoemission spectroscopy. The electronic structures of various transition metal oxide (TMO)-based CGLs and their role in charge generation process are reviewed, addressing the n-type doping impact of organic layers in CGLs, thermal annealing-induced oxygen vacancy in TMOs, and the interfacial stability of CGLs on the device operational lifetime. The resulting energy level alignments are summarized in correspondence with tandem OLED performance.

Local thermal energy as a structural indicator in glasses

Science.gov (United States)

Zylberg, Jacques; Lerner, Edan; Bar-Sinai, Yohai; Bouchbinder, Eran

2017-07-01

Identifying heterogeneous structures in glasses—such as localized soft spots—and understanding structure-dynamics relations in these systems remain major scientific challenges. Here, we derive an exact expression for the local thermal energy of interacting particles (the mean local potential energy change caused by thermal fluctuations) in glassy systems by a systematic low-temperature expansion. We show that the local thermal energy can attain anomalously large values, inversely related to the degree of softness of localized structures in a glass, determined by a coupling between internal stresses—an intrinsic signature of glassy frustration—anharmonicity and low-frequency vibrational modes. These anomalously large values follow a fat-tailed distribution, with a universal exponent related to the recently observed universal ω4ω4 density of states of quasilocalized low-frequency vibrational modes. When the spatial thermal energy field—a “softness field”—is considered, this power law tail manifests itself by highly localized spots, which are significantly softer than their surroundings. These soft spots are shown to be susceptible to plastic rearrangements under external driving forces, having predictive powers that surpass those of the normal modes-based approach. These results offer a general, system/model-independent, physical/observable-based approach to identify structural properties of quiescent glasses and relate them to glassy dynamics.

Impurity energy level in the Haldane gap

International Nuclear Information System (INIS)

Wang Wei; Lu Yu

1995-11-01

An impurity bond J' in a periodic 1D antiferromagnetic spin 1 chain with exchange J is considered. Using the numerical density matrix renormalization group method, we find an impurity energy level in the Haldane gap, corresponding to a bound state near the impurity bond. When J' J. The impurity level appears only when the deviation dev = (J'- J)/J' is greater than B c , which is close to 0.3 in our calculation. (author). 15 refs, 4 figs

Aligned energy-level design for decreasing operation voltage of tandem white organic light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Chang, Chih-Hao, E-mail: chc@saturn.yzu.edu.tw [Department of Photonics Engineering, Yuan Ze University, Chung-Li 32003, Taiwan, ROC (China); Wu, Zih-Jyun; Liang, Yi-Hu; Chang, Yu-Shuo; Chiu, Chuan-Hao; Tai, Cheng-Wei [Department of Photonics Engineering, Yuan Ze University, Chung-Li 32003, Taiwan, ROC (China); Chang, Hsin-Hua, E-mail: hhua3@mail.vnu.edu.tw [Department of Electro-Optical Engineering, Vanung University, Chung-Li 32061, Taiwan, ROC (China)

2013-12-02

In general, organic light-emitting devices (OLEDs) need to operate at higher current density levels to ensure an ample light flux. However, stressed operation will result in poor performance and limited device lifetime. Recently, a tandem structure has been proposed as a pivotal technique to meet the stringent lighting requirements for OLED commercialization, with a research focus on decreasing the concomitant higher operation voltage. Driving two connected emission units (EMUs) in a tandem structure often requires more than twice the driving voltage for a single EMU. This study investigates bipolar host materials and their effective employment in fabricating tandem white phosphorescent OLEDs (PhOLEDs). In addition, the design of a mechanism to align the energy level between the hole transport layer/emitting layer is shown to effectively mitigate operational voltages. In sharp contrast to devices using a unipolar host material, we demonstrate that the turn-on voltage of blue PhOLEDs could be decreased from 3.8 V to 2.7 V through utilizing a bipolar host. Furthermore, applying the proposed techniques to tandem white PhOLEDs produces a luminance of 10{sup 3} cd/m{sup 2} by a 10.1 V driving voltage. - Highlights: • The matched energy level between the hole transport/emitting layer lowers voltages. • Multiple conduction dopants were used to investigate charge generation layer. • Two-color emitters were used to quantify the charge generation strength.

Spectrum and energy levels of five-times ionized zirconium (Zr VI)

International Nuclear Information System (INIS)

Reader, Joseph; Lindsay, Mark D

2016-01-01

We carried out a new analysis of the spectrum of five-times-ionized zirconium Zr VI. For this we used sliding-spark discharges together with normal- and grazing-incidence spectrographs to observe the spectrum from 160 to 2000 Å. These observations showed that the analysis of this spectrum by Khan et al (1985 Phys. Scr. 31 837) contained a significant number of incorrect energy levels. We have now classified ∼420 lines as transitions between 23 even-parity levels 73 odd-parity levels. The 4s 2 4p 5 , 4s4p 6 , 4s 2 4p 4 4d, 5s, 5d, 6s configurations are now complete, although a few levels of 4s 2 4p 4 5d are tentative. We determined Ritz-type wavelengths for ∼135 lines from the optimized energy levels. The uncertainties range from 0.0003 to 0.0020 Å. Hartree–Fock calculations and least-squares fits of the energy parameters to the observed levels were used to interpret the observed configurations. Oscillator strengths for all classified lines were calculated with the fitted parameters. The results are compared with values for the level energies, percentage compositions, and transition probabilities from recent ab initio theoretical calculations. The ionization energy was revised to 777 380 ± 300 cm −1 (96.38 ± 0.04 eV). (paper)

EVALUATION OF ENERGY EFFICIENT USE AT THE LEVEL OF NATIONAL ECONOMY

Directory of Open Access Journals (Sweden)

RUGINĂ V.

2016-03-01

Full Text Available The paper presents the importance of evaluating energy efficient use that is explicitly stipulated in the strategic and legislative documents adopted at the national and international level, including the Directive 2012/27/EU and the Law 121/2014. Energy intensity frequently that is used in international evaluations and comparisons of energy efficient use is also used in Romania. The topic is approached both by specialists and politicians, newspapermen, representatives of the public opinion etc. This indicator has acquired axiomatic valences and its values are presented as unquestionable arguments for incontestable truths. Nevertheless, besides correct and well-balanced approaches one may come across distorted presentations and exaggerations resulting from superficially knowing the problem. The information and data presented in the paper can bring clarifications on this field. In the first place, energy intensity characterizes the economic efficiency of energy utilization and only to little extent the technical efficiency. Its value is directly linked to macroeconomic parameters, among which the parity between the national currency and the currencies in international circulation, the structure of the national economy etc. The paper presents different variants for the interpretation and calculation of the energy intensity indicator value, including the corresponding mathematical models. Based on the primary information obtained from reliable sources (National Institute of Statistics, EUROSTAT data base values of this indicator are calculated in different variants that are considered and comparisons between the obtained results are made. Choosing the variant for defining and calculating energy intensity, respectively, depends on the purpose of the analysis to be carried out and needs to be explicitly presented together with the results obtained. The paper includes recommendations on how the calculation variants and the results obtained by carrying

Structure formation in inhomogeneous Early Dark Energy models

International Nuclear Information System (INIS)

Batista, R.C.; Pace, F.

2013-01-01

We study the impact of Early Dark Energy fluctuations in the linear and non-linear regimes of structure formation. In these models the energy density of dark energy is non-negligible at high redshifts and the fluctuations in the dark energy component can have the same order of magnitude of dark matter fluctuations. Since two basic approximations usually taken in the standard scenario of quintessence models, that both dark energy density during the matter dominated period and dark energy fluctuations on small scales are negligible, are not valid in such models, we first study approximate analytical solutions for dark matter and dark energy perturbations in the linear regime. This study is helpful to find consistent initial conditions for the system of equations and to analytically understand the effects of Early Dark Energy and its fluctuations, which are also verified numerically. In the linear regime we compute the matter growth and variation of the gravitational potential associated with the Integrated Sachs-Wolf effect, showing that these observables present important modifications due to Early Dark Energy fluctuations, though making them more similar to the ΛCDM model. We also make use of the Spherical Collapse model to study the influence of Early Dark Energy fluctuations in the nonlinear regime of structure formation, especially on δ c parameter, and their contribution to the halo mass, which we show can be of the order of 10%. We finally compute how the number density of halos is modified in comparison to the ΛCDM model and address the problem of how to correct the mass function in order to take into account the contribution of clustered dark energy. We conclude that the inhomogeneous Early Dark Energy models are more similar to the ΛCDM model than its homogeneous counterparts

Vibration Control of Structures using Vibro-Impact Nonlinear Energy Sinks

Directory of Open Access Journals (Sweden)

M. Ahmadi

2016-09-01

Full Text Available Using Vibro-Impact Nonlinear Energy Sinks (VI NESs is one of the novel strategies to control structural vibrations and mitigate their seismic response. In this system, a mass is tuned on the structure floor, so that it has a specific distance from an inelastic constraint connected to the floor mass. In case of structure stimulation, the displaced VI NES mass collides with the  inelastic constraint and upon impacts, energy is dissipated. In the present work, VI NES is studied when its parameters, including clearance and stiffness ratio, are simultaneously optimized. Harmony search as a recent meta-heuristic algorithm is efficiently specialized and utilized for the aforementioned continuous optimization problem. The optimized attached VI NES is thus shown to be capable of interacting with the primary structure over a wide range of frequencies. The resulting controlled response is then investigated, in a variety of low and medium rise steel moment frames, via nonlinear dynamic time history analyses. Capability of the VI NES to dissipate siesmic input energy of earthquakes and their capabilitiy in reducing response of srtructures effectively, through vibro-impacts between the energy sink’s mass and the floor mass, is discussed by extracting several performance indices and the corresponding Fourier spectra. Results of the numerical simulations done on some structural model examples reveal that the optimized VI NES has caused successive redistribution of energy from low-frequency high-amplitude vibration modes to high-frequency low-amplitude modes, bringing about the desired attenuation of the structural responses.

Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: optimization of energy level viewing significantly increases lesion contrast.

Science.gov (United States)

Patel, B N; Thomas, J V; Lockhart, M E; Berland, L L; Morgan, D E

2013-02-01

To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40-77). The mean ± SD lesion contrast values (non-tumoural pancreas - tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 keV was 31 ± 25 HU (p = 0

The structure of residential energy demand in Greece

International Nuclear Information System (INIS)

Rapanos, Vassilis T.; Polemis, Michael L.

2006-01-01

This paper attempts to shed light on the determinants of residential energy demand in Greece, and to compare it with some other OECD countries. From the estimates of the short-run and long-run elasticities of energy demand for the period 1965-1999, we find that residential energy demand appears to be price inelastic. Also, we do not find evidence of a structural change probably because of the low efficiency of the energy sector. We find, however, that the magnitude of the income elasticity varies substantially between Greece and other OECD countries

Dual-Level Game-Based Energy Efficiency and Fairness for Green Cellular Networks

Directory of Open Access Journals (Sweden)

Sungwook Kim

2016-01-01

Full Text Available In the recent decades, cellular networks have revolutionized the way of next generation communication networks. However, due to the global climate change, reducing the energy consumption of cellular infrastructures is an important and urgent problem. In this study, we propose a novel two-level cooperative game framework for improving the energy efficiency and fairness in cellular networks. For the energy efficiency, base stations (BSs constantly monitor the current traffic load and cooperate with each other to maximize the energy saving. For the energy fairness, renewable energy can be shared dynamically while ensuring the fairness among BSs. To achieve an excellent cellular network performance, the concepts of the Raiffa Bargaining Solution and Jain’s fairness are extended and practically applied to our dual-level cooperative game model. Through system level simulations, the proposed scheme is evaluated and compared with other existing schemes. The simulation results show that our two-level game approach outperforms the existing schemes in providing a better fair-efficient system performance.

Superconducting magnetic energy storage apparatus structural support system

Science.gov (United States)

Withers, Gregory J.; Meier, Stephen W.; Walter, Robert J.; Child, Michael D.; DeGraaf, Douglas W.

1992-01-01

A superconducting magnetic energy storage apparatus comprising a cylindrical superconducting coil; a cylindrical coil containment vessel enclosing the coil and adapted to hold a liquid, such as liquefied helium; and a cylindrical vacuum vessel enclosing the coil containment vessel and located in a restraining structure having inner and outer circumferential walls and a floor; the apparatus being provided with horizontal compression members between (1) the coil and the coil containment vessel and (2) between the coil containment vessel and the vacuum vessel, compression bearing members between the vacuum vessel and the restraining structure inner and outer walls, vertical support members (1) between the coil bottom and the coil containment vessel bottom and (2) between the coil containment vessel bottom and the vacuum vessel bottom, and external supports between the vacuum vessel bottom and the restraining structure floor, whereby the loads developed by thermal and magnetic energy changes in the apparatus can be accommodated and the structural integrity of the apparatus be maintained.

Electronic structure of the Ga1-xCr xN studied by high-energy photoemission spectroscopy

International Nuclear Information System (INIS)

Kim, J.J.; Makino, H.; Yao, T.; Takata, Y.; Kobayashi, K.; Yamamoto, T.; Hanada, T.; Cho, M.W.; Ikenaga, E.; Yabashi, M.; Miwa, D.; Nishino, Y.; Tamasaku, K.; Ishikawa, T.; Shin, S.

2005-01-01

Valence band spectra of Ga 1-x Cr x N have been investigated by high-energy photoemission spectroscopy at the photon energy of 5.95 keV. Cr doping does introduce a novel electronic structure in the bandgap and causes some change in valence band structure. Based on the first-principle calculation, Cr-associated electronic levels in the bandgap are assigned to nonbonding and antibonding d states while the change of the valence band suggests that the Ga 4s originated states are significantly modified through hybridization with the Cr 3d orbital. The present result evidences that the Ga valence electrons are considerably modified through the interaction with the second nearest-neighbour Cr atoms

Parametric Statistics of Individual Energy Levels in Random Hamiltonians

OpenAIRE

Smolyarenko, I. E.; Simons, B. D.

2002-01-01

We establish a general framework to explore parametric statistics of individual energy levels in disordered and chaotic quantum systems of unitary symmetry. The method is applied to the calculation of the universal intra-level parametric velocity correlation function and the distribution of level shifts under the influence of an arbitrary external perturbation.

Algebraic structure of general electromagnetic fields and energy flow

International Nuclear Information System (INIS)

Hacyan, Shahen

2011-01-01

Highlights: → Algebraic structure of general electromagnetic fields in stationary spacetime. → Eigenvalues and eigenvectors of the electomagnetic field tensor. → Energy-momentum in terms of eigenvectors and Killing vector. → Explicit form of reference frame with vanishing Poynting vector. → Application of formalism to Bessel beams. - Abstract: The algebraic structures of a general electromagnetic field and its energy-momentum tensor in a stationary space-time are analyzed. The explicit form of the reference frame in which the energy of the field appears at rest is obtained in terms of the eigenvectors of the electromagnetic tensor and the existing Killing vector. The case of a stationary electromagnetic field is also studied and a comparison is made with the standard short-wave approximation. The results can be applied to the general case of a structured light beams, in flat or curved spaces. Bessel beams are worked out as example.

System-Level Coupled Modeling of Piezoelectric Vibration Energy Harvesting Systems by Joint Finite Element and Circuit Analysis

Directory of Open Access Journals (Sweden)

Congcong Cheng

2016-01-01

Full Text Available A practical piezoelectric vibration energy harvesting (PVEH system is usually composed of two coupled parts: a harvesting structure and an interface circuit. Thus, it is much necessary to build system-level coupled models for analyzing PVEH systems, so that the whole PVEH system can be optimized to obtain a high overall efficiency. In this paper, two classes of coupled models are proposed by joint finite element and circuit analysis. The first one is to integrate the equivalent circuit model of the harvesting structure with the interface circuit and the second one is to integrate the equivalent electrical impedance of the interface circuit into the finite element model of the harvesting structure. Then equivalent circuit model parameters of the harvesting structure are estimated by finite element analysis and the equivalent electrical impedance of the interface circuit is derived by circuit analysis. In the end, simulations are done to validate and compare the proposed two classes of system-level coupled models. The results demonstrate that harvested powers from the two classes of coupled models approximate to theoretic values. Thus, the proposed coupled models can be used for system-level optimizations in engineering applications.

Energy Levels of Defects Created in Silicon Supersaturated with Transition Metals

Science.gov (United States)

García, H.; Castán, H.; Dueñas, S.; García-Hemme, E.; García-Hernansaz, R.; Montero, D.; González-Díaz, G.

2018-03-01

Intermediate-band semiconductors have attracted much attention for use in silicon-based solar cells and infrared detectors. In this work, n-Si substrates have been implanted with very high doses (1013 cm-2 and 1014 cm-2) of vanadium, which gives rise to a supersaturated layer inside the semiconductor. However, the Mott limit was not exceeded. The energy levels created in the supersaturated silicon were studied in detail by means of thermal admittance spectroscopy. We found a single deep center at energy near E C - 200 meV. This value agrees with one of the levels found for vanadium in silicon. The capture cross-section values of the deep levels were also calculated, and we found a relationship between the capture cross-section and the energy position of the deep levels which follows the Meyer-Neldel rule. This process usually appears in processes involving multiple excitations. The Meyer-Neldel energy values agree with those previously obtained for silicon supersaturated with titanium and for silicon contaminated with iron.

Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe2

International Nuclear Information System (INIS)

Nelson, A.J.; Berry, G.; Rockett, A.

1997-01-01

Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe 2 , one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies

Electronic structure evolution and energy level alignment at C60/4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl) benzenamine]/MoOx/indium tin oxide interfaces

Science.gov (United States)

Liu, Xiaoliang; Yi, Shijuan; Wang, Chenggong; Wang, Congcong; Gao, Yongli

2014-04-01

The electronic structure evolution and energy level alignment have been investigated at interfaces comprising fullerene (C60)/4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl) benzenamine] (TAPC)/ molybdenum oxide (MoOx)/ indium tin oxide with ultraviolet photoemission spectroscopy and inverse photoemission spectroscopy. With deposition of TAPC upon MoOx, a dipole of 1.58 eV was formed at the TAPC/MoOx interface due to electron transfer from TAPC to MoOx. The highest occupied molecular orbital (HOMO) onset of TAPC was pinned closed to the Fermi level, leading to a p-doped region and thus increasing the carrier concentration at the very interface. The downward band bending and the resulting built-in field in TAPC were favorable for the hole transfer toward the TAPC/MoOx interface. The rigid downward shift of energy levels of TAPC indicated no significant interface chemistry at the interface. With subsequent deposition of C60 on TAPC, a dipole of 0.27 eV was observed at the C60/TAPC heterojunction due to the electron transfer from TAPC to C60. This led to a drop of the HOMO of TAPC near the C60/TAPC interface, and hence further enhanced the band bending in TAPC. The band bending behavior was also observed in C60, similarly creating a built-in field in C60 film and improving the electron transfer away from the C60/TAPC interface. It can be deduced from the interface analysis that a promising maximum open circuit voltage of 1.5 eV is achievable in C60/TAPC-based organic photovoltaic cells.

Energy efficiency, human behavior, and economic growth: Challenges to cutting energy demand to sustainable levels

Science.gov (United States)

Santarius, Tilman

2015-03-01

Increasing energy efficiency in households, transportation, industries, and services is an important strategy to reduce energy service demand to levels that allow the steep reduction of greenhouse gases, and a full fledged switch of energy systems to a renewable basis. Yet, technological efficiency improvements may generate so-called rebound effects, which may `eat up' parts of the technical savings potential. This article provides a comprehensive review of existing research on these effects, raises critiques, and points out open questions. It introduces micro-economic rebound effect and suggests extending consumer-side analysis to incorporate potential `psychological rebound effects.' It then discusses meso-economic rebound effects, i.e. producer-side and market-level rebounds, which so far have achieved little attention in the literature. Finally, the article critically reviews evidence for macro-economic rebound effects as energy efficiency-induced economic growth impacts. For all three categories, the article summarizes assessments of their potential quantitative scope, while pointing out remaining methodological weaknesses and open questions. As a rough "rule of thumb", in the long term and on gross average, only half the technical savings potential of across-the-board efficiency improvements may actually be achieved in the real world. Policies that aim at cutting energy service demand to sustainable levels are well advised to take due note of detrimental behavioral and economic growth impacts, and should foster policies and measures that can contain them.

Structure determination of Ga As (110) p (1 x 1) - Sb using scanned-energy photoelectron diffraction

International Nuclear Information System (INIS)

Ascolani, H.; Asensio, M.C.; Fritzsche, W.

1996-01-01

Photoelectron diffraction (PD) in the scanned-energy mode has proven to be a powerfull tool for structural determination of the first few surface layers. The scanned-energy mode involves the measurement of the intensity of photoelectrons emitted from a core level as a function of the incident photon energy for different emission directions. The atom specificity of PD allows the investigation of the local structure of adsorbed atoms without interference of the substrate. In addition, if a measurable chemical shift exists, this technique is also able to discriminate between atoms of the same species adsorbed in inequivalent sites. The Ga As (110) p (1x1)-Sb (1 ML) surface represents a prototype system to study atom adsorption on III-V semiconductors. The epitaxial continued layer structure (ECLS) is generally accepted as the geometry corresponding to this surface, although some authors have claimed that the p 3 model forms a stable geometry equivalent to the ECLS, and that it provides an equally good description of their experimental results. So far, the conclusions about the atomic structure of this surface had been derived on the basis of indirect methods. This work exploits to the utmost the possibilities of analysis offered by the scanned-energy PD technique, namely, chemical shift analysis and direct inversion. The energy spectrum of Sb-4d photoelectrons emitted from the Ga As (110)-p (1x1) Sb surface has two chemically-shifted components. We have inverted the scanned-energy photoelectron diffraction data corresponding to these two components to obtain the positions of the Ga and As atoms which are nearest neighbors of two inequivalent Sb atoms. Our results contradict various models proposed for this surface and are consistent only with the ECLS. For a more detailed atomic structure determination, the best fit between experiment and multiple-scattering calculations was determined by a trial-and-error procedure. (author)

Two-step values for games with two-level communication structure

NARCIS (Netherlands)

Béal, Silvain; Khmelnitskaya, Anna Borisovna; Solal, Philippe

TU games with two-level communication structure, in which a two-level communication structure relates fundamentally to the given coalition structure and consists of a communication graph on the collection of the a priori unions in the coalition structure, as well as a collection of communication

Attosecond time-energy structure of X-ray free-electron laser pulses

Science.gov (United States)

Hartmann, N.; Hartmann, G.; Heider, R.; Wagner, M. S.; Ilchen, M.; Buck, J.; Lindahl, A. O.; Benko, C.; Grünert, J.; Krzywinski, J.; Liu, J.; Lutman, A. A.; Marinelli, A.; Maxwell, T.; Miahnahri, A. A.; Moeller, S. P.; Planas, M.; Robinson, J.; Kazansky, A. K.; Kabachnik, N. M.; Viefhaus, J.; Feurer, T.; Kienberger, R.; Coffee, R. N.; Helml, W.

2018-04-01

The time-energy information of ultrashort X-ray free-electron laser pulses generated by the Linac Coherent Light Source is measured with attosecond resolution via angular streaking of neon 1s photoelectrons. The X-ray pulses promote electrons from the neon core level into an ionization continuum, where they are dressed with the electric field of a circularly polarized infrared laser. This induces characteristic modulations of the resulting photoelectron energy and angular distribution. From these modulations we recover the single-shot attosecond intensity structure and chirp of arbitrary X-ray pulses based on self-amplified spontaneous emission, which have eluded direct measurement so far. We characterize individual attosecond pulses, including their instantaneous frequency, and identify double pulses with well-defined delays and spectral properties, thus paving the way for X-ray pump/X-ray probe attosecond free-electron laser science.

Energy-level statistics and time relaxation in quantum systems

International Nuclear Information System (INIS)

Gruver, J.L.; Cerdeira, H.A.; Aliaga, J.; Mello, P.A.; Proto, A.N.

1997-05-01

We study a quantum-mechanical system, prepared, at t = 0, in a model state, that subsequently decays into a sea of other states whose energy levels form a discrete spectrum with given statistical properties. An important quantity is the survival probability P(t), defined as the probability, at time t, to find the system in the original model state. Our main purpose is to analyze the influence of the discreteness and statistical properties of the spectrum on the behavior of P(t). Since P(t) itself is a statistical quantity, we restrict our attention to its ensemble average , which is calculated analytically using random-matrix techniques, within certain approximations discussed in the text. We find, for , an exponential decay, followed by a revival, governed by the two-point structure of the statistical spectrum, thus giving a nonzero asymptotic value for large t's. The analytic result compares well with a number of computer simulations, over a time range discussed in the text. (author). 17 refs, 1 fig

Enhanced Performance of DSSCs Based on the Insertion Energy Level of CdS Quantum Dots

Directory of Open Access Journals (Sweden)

Xiaoping Zou

2014-01-01

Full Text Available Cadmium sulfide (CdS quantum dots (QDs are assembled onto the TiO2 films by chemical bath deposition method (CBD. And the QDs size is controlled by the times of CBD cycles. They are characterized by UV-visible absorption. To avoid the photo corrosion and electrolyte corrosion, CdS and N719 are sequentially assembled onto the nanocrystalline TiO2 films to prepare a CdS/N719 cosensitized photo electrode for the dye-sensitized solar cells. In the structure of TiO2/CdS/N719 electrode, the reorganization of energy levels between CdS and N719 forms a stepwise structure of band-edge levels which is advantageous to the electron injection and hole recovery of CdS and N719 QDs. The open circuit voltage (Voc, short circuit current density (Jsc, and efficiency are increased.

Energy. Political contacts at national, state and European level; Energie. Politikkontakte Bund, Land, Europa

Energy Technology Data Exchange (ETDEWEB)

Holzapfel, Andreas (ed.)

2013-04-01

The manual is in three sections: 1. Parliaments and governments, survey and organization; 2. Biographic section, with 304 biography; 3. Index of names. The first section informs on the organizational structure of parliaments and governments. The subject of energy is discussed three times, i.e. in 'Economics', 'Environment', and 'Research'. For each parliament, the members of the energy policy TCs are listed, followed by names and contact addresses of the senior officials and departments with contact data, both on a national, state, and European scale. The second section contains the biographies of energy policy experts of the German parliament and government, the sixteen land parliaments and governments, and the European Commissions. As the subject of energy is highly interdisciplinary, the authors selected the energy policy committees of the German parliament and state parliaments. The biographies of the committee members are presented in the text.

Treatment of Electronic Energy Level Transition and Ionization Following the Particle-Based Chemistry Model

Science.gov (United States)

Liechty, Derek S.; Lewis, Mark

2010-01-01

A new method of treating electronic energy level transitions as well as linking ionization to electronic energy levels is proposed following the particle-based chemistry model of Bird. Although the use of electronic energy levels and ionization reactions in DSMC are not new ideas, the current method of selecting what level to transition to, how to reproduce transition rates, and the linking of the electronic energy levels to ionization are, to the author s knowledge, novel concepts. The resulting equilibrium temperatures are shown to remain constant, and the electronic energy level distributions are shown to reproduce the Boltzmann distribution. The electronic energy level transition rates and ionization rates due to electron impacts are shown to reproduce theoretical and measured rates. The rates due to heavy particle impacts, while not as favorable as the electron impact rates, compare favorably to values from the literature. Thus, these new extensions to the particle-based chemistry model of Bird provide an accurate method for predicting electronic energy level transition and ionization rates in gases.

Structural level set inversion for microwave breast screening

International Nuclear Information System (INIS)

Irishina, Natalia; Álvarez, Diego; Dorn, Oliver; Moscoso, Miguel

2010-01-01

We present a new inversion strategy for the early detection of breast cancer from microwave data which is based on a new multiphase level set technique. This novel structural inversion method uses a modification of the color level set technique adapted to the specific situation of structural breast imaging taking into account the high complexity of the breast tissue. We only use data of a few microwave frequencies for detecting the tumors hidden in this complex structure. Three level set functions are employed for describing four different types of breast tissue, where each of these four regions is allowed to have a complicated topology and to have an interior structure which needs to be estimated from the data simultaneously with the region interfaces. The algorithm consists of several stages of increasing complexity. In each stage more details about the anatomical structure of the breast interior is incorporated into the inversion model. The synthetic breast models which are used for creating simulated data are based on real MRI images of the breast and are therefore quite realistic. Our results demonstrate the potential and feasibility of the proposed level set technique for detecting, locating and characterizing a small tumor in its early stage of development embedded in such a realistic breast model. Both the data acquisition simulation and the inversion are carried out in 2D

Protein loop modeling using a new hybrid energy function and its application to modeling in inaccurate structural environments.

Directory of Open Access Journals (Sweden)

Hahnbeom Park

Full Text Available Protein loop modeling is a tool for predicting protein local structures of particular interest, providing opportunities for applications involving protein structure prediction and de novo protein design. Until recently, the majority of loop modeling methods have been developed and tested by reconstructing loops in frameworks of experimentally resolved structures. In many practical applications, however, the protein loops to be modeled are located in inaccurate structural environments. These include loops in model structures, low-resolution experimental structures, or experimental structures of different functional forms. Accordingly, discrepancies in the accuracy of the structural environment assumed in development of the method and that in practical applications present additional challenges to modern loop modeling methods. This study demonstrates a new strategy for employing a hybrid energy function combining physics-based and knowledge-based components to help tackle this challenge. The hybrid energy function is designed to combine the strengths of each energy component, simultaneously maintaining accurate loop structure prediction in a high-resolution framework structure and tolerating minor environmental errors in low-resolution structures. A loop modeling method based on global optimization of this new energy function is tested on loop targets situated in different levels of environmental errors, ranging from experimental structures to structures perturbed in backbone as well as side chains and template-based model structures. The new method performs comparably to force field-based approaches in loop reconstruction in crystal structures and better in loop prediction in inaccurate framework structures. This result suggests that higher-accuracy predictions would be possible for a broader range of applications. The web server for this method is available at http://galaxy.seoklab.org/loop with the PS2 option for the scoring function.

Energy Performance of a Light Wood-Timber Structured House in the Severely Cold Region of China

Directory of Open Access Journals (Sweden)

Meng Zhen

2018-05-01

Full Text Available The purpose of the study was to determine the energy performance of a timber structured house built in Harbin, a severely cold region of China. The research team conducted a field test on the house that lasted three months (15 January–15 April 2008. The test included the winter heating energy consumption, average indoor temperature and relative humidity, building heat storage capacity, heat transfer coefficient of the wall, total air volume of air-conditioning system, etc. The test results showed that the total heating was calculated to be 73,240.59 MJ in winter. Thermal imaging tests were carried out on the house and found no obvious thermal defects such as thermal bridges. In conclusion, the timber structured house has a good level of building energy conservation and would provide a good exemplary for green building design and construction in similar severely cold regions in the world.

Path towards achieving of China's 2020 carbon emission reduction target-A discussion of low-carbon energy policies at province level

International Nuclear Information System (INIS)

Wang Run; Liu Wenjuan; Xiao Lishan; Liu Jian; Kao, William

2011-01-01

Following the announcement of the China's 2020 national target for the reduction of the intensity of carbon dioxide emissions per unit of GDP by 40-45% compared with 2005 levels, Chinese provincial governments prepared to restructure provincial energy policy and plan their contribution to realizing the State reduction target. Focusing on Fujian and Anhui provinces as case studies, this paper reviews two contrasting policies as a means for meeting the national reduction target. That of the coastal province of Fujian proposes to do so largely through the development of nuclear power, whilst the coal-rich province of Anhui proposes to do so through its energy consumption rate rising at a lower rate than that of the rise in GDP. In both cases renewable energy makes up a small proportion of their proposed 2020 energy structures. The conclusion discusses in depth concerns about nuclear power policy, energy efficiency, energy consumption strategy and problems in developing renewable energy. - Research Highlights: → We review two contrasting policies as a means for meeting the national reduction target of carbon emission in two provinces. → Scenario review of energy structure in Fujian and Anhui Provinces to 2020. → We discuss concerns about nuclear power policy, energy efficiency, energy consumption strategy and problems in developing renewable energy.

Energy-Storing Structures: Composite Capacitors and Batteries

Science.gov (United States)

2012-07-30

circuit board (PCB) prepreg C electrode dielectric Autoclave-processed structural capacitor • Objective: High energy density, scalable...Continued scaling (lab safety limit  100 J) – Beyond commercial FR4 prepreg  high dielectric additives, super- clean prepregging

Research into the Energy Output of Asymmetric Cylindrical Structure under Internal Explosion Loading

Directory of Open Access Journals (Sweden)

Liangliang Ding

2018-04-01

Full Text Available The energy output characteristic of an asymmetric cylindrical structure under internal explosion loading has significant research value in the field of the national defense industry. This paper took the D-shaped structure as the research object. Three groups of experiments (D-90°, D-120°, D-150° were carried out. The D-shaped structure showed that fragments are concentrated in the middle and are sparse on both sides. Moreover, the fragment density decreased with the increase of the azimuth angle. The fragment velocities, which were measured from high-speed photography and an oscilloscope, coincided well with each other, and decreased with an increase in the central angle. Compared with the cylindrical structure, the fragment energy gain of the D-shaped structure is significant; the total energy and energy density of the three D-shaped structures were very close to each other. This indicates that D-120° is the optimal solution among the three D-shaped structures and it can provide guidance for the future design of D-shaped structures to achieve higher energy output.

Fluid/structure interaction in BERDYNE (Level 4)

International Nuclear Information System (INIS)

Fox, M.J.H.

1988-02-01

A fluid-structure interaction capability has been developed for Level 4 of the finite element dynamics code BERDYNE, as part of the BERSAFE structural analysis system. This permits analysis of small amplitude free or forced vibration of systems comprising elastic structural components and inviscid volumes of possibly compressible fluid. Free fluid surfaces under the influence of gravity may be present. The formulation chosen uses the rigid walled fluid modes, calculated in a preliminary stage, as a basis for description of the coupled system, providing symmetric system matrices for which efficient solution procedures are available. The inclusion of the fluid modal variables within the system matrices is carried out through the use of the BERDYNE 'substructuring' feature, which allows the inclusion of very general 'super-elements' among the normal structural elements. The program also has a seismic analysis capability, used for the analysis of fluid-structure systems subjected to a specified support acceleration time history. In this case analysis is carried out in terms of relative structural motions, but absolute fluid pressures. Application of the BERDYNE fluid/structure interaction capability to some simple test cases produced results in good agreement with results obtained by analytic or independent numerical techniques. Full instructions on the use of the facility will be included in the BERDYNE Level 4 documentation. Interim documentation for the pre-release version is available from the author. (author)

Energy-level alignment at interfaces between manganese phthalocyanine and C60

Directory of Open Access Journals (Sweden)

Daniel Waas

2017-04-01

Full Text Available We have used photoelectron spectroscopy to determine the energy-level alignment at organic heterojunctions made of manganese phthalocyanine (MnPc and the fullerene C60. We show that this energy-level alignment depends upon the preparation sequence, which is explained by different molecular orientations. Moreover, our results demonstrate that MnPc/C60 interfaces are hardly suited for application in organic photovoltaic devices, since the energy difference of the two lowest unoccupied molecular orbitals (LUMOs is rather small.

The influence of habitat structure on energy allocation tactics in an estuarine batch spawner

Science.gov (United States)

Brigolin, D.; Cavraro, F.; Zanatta, V.; Pastres, R.; Malavasi, S.

2016-04-01

Trade-off between fecundity and survival was tested in a batch spawner, the Mediterranean killifish Aphanius fasciatus, using an integrated modelling-data approach based on previously collected empirical data. Two sites of the lagoon of Venice (Northern Adriatic sea, Italy) were selected in order to compare the energy allocation between growth and reproduction in two contrasting habitats. These were characterised by high and comparable level of richness in basal resources, but showed two different mortality schedules: an open natural salt marsh, exposed to high level of predation, and a confined artificial site protected from piscivorous predation. By means of a bioenergetic Scope for Growth model, developed and calibrated for the specific goals of this work, we compared the average individual life history between the two habitats. The average individual life history is characterised by a higher number of spawning events and lower per-spawning investment in the confined site exposed to lower predation risk, compared to the site connected with the open lagoon. Thus, model predictions suggest that habitat structure with different extrinsic mortality schedules may shape the life history strategy in modulating the pattern of energy allocation. Model application highlights the central role of energy partitioning through batch spawning, in determining the life history strategy. The particular ovary structure of a batch spawner seems therefore to allow the fish to modulate timing and investment of spawning events, shaping the optimal life history in relation to the environmental conditions.

On Low Energy Levels in {sup 185}W

Energy Technology Data Exchange (ETDEWEB)

Malmskog, S G; Hoejeberg, M; Berg, V

1969-02-15

Gamma ray spectra in the decay of {sup 185}Ta and {sup 185m}W have been studied with Ge (Li) detectors. The {sup 185m}W isomeric transition at 131.6 keV is shown to be of E3 multipolarity. A level scheme of {sup 185}W is proposed with the following energy levels (energies in keV, spin and K quantum numbers in brackets): 0 (3/2{sup -} 3/2), 23.5 (1/2{sup -} 1/2), 65.9 (5/2{sup -} 3/2), 93.5 (3/2{sup -} 1/2) (uncertain), 173.9 (7/2{sup -} 3/2), 188.1 (5/2{sup -} 1/2), 197.5 (11/2{sup +} 11/2) , 243.5 (7/2{sup -} 7/2), and 390.8 (9/2{sup -} 7/2)

Structural, photoconductive, thermoelectric and activation energy ...

Indian Academy of Sciences (India)

2016-07-21

Jul 21, 2016 ... This report investigated the structural, optical and electrical properties of V-doped SnO2 thin films deposited using spray .... SnO2 films were deposited on rotating hot substrates under the ... cal band gap energy (Eg) for V-doped SnO2 thin films ..... by Sn4+, resulting in the generation of free electron,.

Energy efficiency, human behavior, and economic growth: Challenges to cutting energy demand to sustainable levels

Energy Technology Data Exchange (ETDEWEB)

Santarius, Tilman, E-mail: tilman@santarius.de [Visiting Scholar, Institute of European Studies and Energy and Resources Group, University of California, Berkeley, 310 Barrows Hall, Berkeley, CA 94720-3050 (United States)

2015-03-30

Increasing energy efficiency in households, transportation, industries, and services is an important strategy to reduce energy service demand to levels that allow the steep reduction of greenhouse gases, and a full fledged switch of energy systems to a renewable basis. Yet, technological efficiency improvements may generate so-called rebound effects, which may ‘eat up’ parts of the technical savings potential. This article provides a comprehensive review of existing research on these effects, raises critiques, and points out open questions. It introduces micro-economic rebound effect and suggests extending consumer-side analysis to incorporate potential ‘psychological rebound effects.’ It then discusses meso-economic rebound effects, i.e. producer-side and market-level rebounds, which so far have achieved little attention in the literature. Finally, the article critically reviews evidence for macro-economic rebound effects as energy efficiency-induced economic growth impacts. For all three categories, the article summarizes assessments of their potential quantitative scope, while pointing out remaining methodological weaknesses and open questions. As a rough “rule of thumb”, in the long term and on gross average, only half the technical savings potential of across-the-board efficiency improvements may actually be achieved in the real world. Policies that aim at cutting energy service demand to sustainable levels are well advised to take due note of detrimental behavioral and economic growth impacts, and should foster policies and measures that can contain them.

Spectrum and energy levels of six-times-ionized molybdenum (Mo VII)

International Nuclear Information System (INIS)

Reader, J.

1990-01-01

The spectrum of the kryptonlike ion Mo VII was observed from 140 to 2274 A with sliding-spark discharges on 10.7-m normal- and grazing-incidence spectrographs. Experimental energies were determined for all levels of the 4s 2 4p 6 , 4s 2 4p 5 4d, 4f, 5s, 5p, 5d, 5f, 5g, and 4s4p 6 4d configurations. A few levels of the 4s 2 4p 4 4d 2 configuration were also found. A total of 399 lines were classified as transitions between 86 observed levels. The observed configurations were theoretically interpreted. The energy parameters determined by least-squares fits to the observed levels are compared with Hartree--Fock calculations. A revised value of the ionization energy was obtained by using the energy of the 4p 5 5g configuration together with an isoelectronically extrapolated value of the effective quantum number n(5g). The adopted limit is 1 013 340±200 cm -1 (125.64±0.02 eV)

Electric ignition energy evaluation and the energy distribution structure of energy released in electrostatic discharge process

International Nuclear Information System (INIS)

Liu Qingming; Huang Jinxiang; Shao Huige; Zhang Yunming

2017-01-01

Ignition energy is one of the important parameters of flammable materials, and evaluating ignition energy precisely is essential to the safety of process industry and combustion science and technology. By using electric spark discharge test system, a series of electric spark discharge experiments were conducted with the capacitor-stored energy in the range of 10 J, 100 J, and 1000 J, respectively. The evaluation method for energy consumed by electric spark, wire, and switch during capacitor discharge process has been studied respectively. The resistance of wire, switch, and plasma between electrodes has been evaluated by different methods and an optimized evaluation method has been obtained. The electric energy consumed by wire, electric switch, and electric spark-induced plasma between electrodes were obtained and the energy structure of capacitor-released energy was analyzed. The dynamic process and the characteristic parameters (the maximum power, duration of discharge process) of electric spark discharge process have been analyzed. Experimental results showed that, electric spark-consumed energy only accounts for 8%–14% of the capacitor-released energy. With the increase of capacitor-released energy, the duration of discharge process becomes longer, and the energy of plasma accounts for more in the capacitor-released energy. The power of electric spark varies with time as a damped sinusoids function and the period and the maximum value increase with the capacitor-released energy. (paper)

Open cycle ocean thermal energy conversion system structure

Science.gov (United States)

Wittig, J. Michael

1980-01-01

A generally mushroom-shaped, open cycle OTEC system and distilled water producer which has a skirt-conduit structure extending from the enlarged portion of the mushroom to the ocean. The enlarged part of the mushroom houses a toroidal casing flash evaporator which produces steam which expands through a vertical rotor turbine, partially situated in the center of the blossom portion and partially situated in the mushroom's stem portion. Upon expansion through the turbine, the motive steam enters a shell and tube condenser annularly disposed about the rotor axis and axially situated beneath the turbine in the stem portion. Relatively warm ocean water is circulated up through the radially outer skirt-conduit structure entering the evaporator through a radially outer portion thereof, flashing a portion thereof into motive steam, and draining the unflashed portion from the evaporator through a radially inner skirt-conduit structure. Relatively cold cooling water enters the annular condenser through the radially inner edge and travels radially outwardly into a channel situated along the radially outer edge of the condenser. The channel is also included in the radially inner skirt-conduit structure. The cooling water is segregated from the potable, motive steam condensate which can be used for human consumption or other processes requiring high purity water. The expansion energy of the motive steam is partially converted into rotational mechanical energy of the turbine rotor when the steam is expanded through the shaft attached blades. Such mechanical energy drives a generator also included in the enlarged mushroom portion for producing electrical energy. Such power generation equipment arrangement provides a compact power system from which additional benefits may be obtained by fabricating the enclosing equipment, housings and component casings from low density materials, such as prestressed concrete, to permit those casings and housings to also function as a floating

Effects of different levels of protein-to-energy ratios on nutrient ...

African Journals Online (AJOL)

ELOHO

2012-08-24

Aug 24, 2012 ... structure and morphology of digestive tract of birds. This study found that ... structure and function. Lipids are the most important energy substance of .... A checklist on the classification and distribution of the birds of China.

Materializing a responsive interior: designing minimum energy structures

DEFF Research Database (Denmark)

Mossé, Aurélie; Kofod, Guggi; Ramsgaard Thomsen, Mette

2011-01-01

This paper discusses a series of design-led experiments investigating future possibilities for architectural materialization relying on minimum energy structures as an example of adaptive structure. The structures have been made as laminates of elastic membrane under high tension with flexible...... (Lendlein, Kelch 2002) or light (van Oosten, Bastiaansen et al. 2009). All in all, this approach could form a whole new design paradigm, in which efficient 2D-manufacturing can lead to highly flexible, low weight and adaptable 3D-structures. This is illustrated by the design and manufacture of electro...

Energy innovation and renewable energy consumption in the correction of air pollution levels

International Nuclear Information System (INIS)

Alvarez-Herranz, Agustin; Balsalobre-Lorente, Daniel; Shahbaz, Muhammad; Cantos, José María

2017-01-01

This study analyses the relationship between economic growth and environmental pollution. Specifically, it investigates the presence of an environmental Kuznets curve (EKC) in 17 OECD countries over the period of 1990–2012. The results confirm the existence of an N-shaped EKC relationship between income and environmental degradation. The study offers a novel methodological contribution that makes it possible to explain the environmental pollution process through the analysis of low-carbon technologies. This demonstrates how income levels affect energy consumption and how higher energy demand leads to a larger share of fossil sources in the energy mix and, thus, increased greenhouse gas (GHG) emissions. The effect on per capita GHG emissions is explored in a model containing a dampening variable that moderates the relationship between energy consumption and income. This empirical evidence helps to explain the interaction between energy regulation, economic growth and carbon emissions. This study also confirms the positive effect that energy innovation process exerts on environmental pollution. Finally, it is noted that renewable energy sources help to improve air quality. - Highlights: • An inverted N-shaped relationship between economic growth and environmental degradation in OECD countries is validated. • Energy regulatory policies exert positive effect on environmental quality. • Energy innovation processes delays the technical obsolescence. • Energy innovation process requires a time lag to become fully efficient.

Excitation energy and angular momentum dependence of the nuclear level densities

International Nuclear Information System (INIS)

Razavi, R.; Kakavand, T.; Behkami, A. N.

2007-01-01

We have investigated the excitation energy (E) dependence of nuclear level density for Bethe formula and constant temperature model. The level density parameter aa nd the back shifted energy from the Bethe formula are obtained by fitting the complete level schemes. Also the level density parameters from the constant temperature model have been determined for several nuclei. we have shown that the microscopic theory provides more precise information on the nuclear level densities. On the other hand, the spin cut-off parameter and effective moment of inertia are determined by studying of the angular momentum (J) dependence of the nuclear level density, and effective moment of inertia is compared with rigid body value.

Analysis of the Potential Impacts on China’s Industrial Structure in Energy Consumption

Directory of Open Access Journals (Sweden)

Yushen Tian

2017-12-01

Full Text Available Industrial structure is one of the main factors that determine energy consumption. Based on China’s energy consumption in 2015 and the goals in 13th Five-Year Plan for Economic and Social Development of the People’s Republic of China (The 13th Five-Year Plan, this paper established an input–output fuzzy multi-objective optimization model to estimate the potential impacts of China’s industrial structure on energy consumption in 2015. Results showed that adjustments to industrial structure could save energy by 19% (1129.17 million ton standard coal equivalent (Mtce. Second, China’s equipment manufacturing industry has a large potential to save energy. Third, the development of several high energy intensive and high carbon intensive sectors needs to be strictly controlled, including Sector 25 (electricity, heat production, and supply industry, Sector 11 (manufacture of paper and stationery, printing, and Sector 14 (non-metallic mineral products industry. Fourth, the territory industry in China has a great potential for energy saving, while its internal structure still needs to be upgraded. Finally, we provide policy suggestions that may be adopted to reduce energy consumption by adjusting China’s industrial structure.

Electron impact excitation of fine-structure levels of neon-like titanium (Ti XIII)

International Nuclear Information System (INIS)

Gupta, G.P.; Deb, N.C.; Msezane, A.Z.

1999-01-01

The authors present results of a Breit-Pauli R-matrix calculation for the electron impact excitation of neon-like titanium, in which the 27 lowest fine-structure target levels arising out of the 4 lowest configurations 2s 2 2p 6 , 2s 2 2p 5 3s, 2s 2 2p 5 3p, and 2s 2 2p 5 3d are included. These target levels are represented by configuration interaction wave functions using the 1s, 2s, 2p, 3s, 3p, and 3d basic orbitals. The relativistic effects are included in the Breit-Pauli approximation via one-body mass correction, Darwin, and spin-orbit interaction terms in the scattering equations. For many transitions, complex resonance structures are found in the excitation cross sections. The excitation cross sections are integrated over a Maxwellian distribution of electron energies to give electron excitation rate coefficients over a wide temperature range from 150 to 600 eV. The relative populations for different electron densities and temperatures are also presented

Multifunctional Composites for Future Energy Storage in Aerospace Structures

Directory of Open Access Journals (Sweden)

Till Julian Adam

2018-02-01

Full Text Available Multifunctionalization of fiber-reinforced composites, especially by adding energy storage capabilities, is a promising approach to realize lightweight structural energy storages for future transport vehicles. Compared to conventional energy storage systems, energy density can be increased by reducing parasitic masses of non-energy-storing components and by benefitting from the composite meso- and microarchitectures. In this paper, the most relevant existing approaches towards multifunctional energy storages are reviewed and subdivided into five groups by distinguishing their degree of integration and their scale of multifunctionalization. By introducing a modified range equation for battery-powered electric aircrafts, possible range extensions enabled by multifunctionalization are estimated. Furthermore, general and aerospace specific potentials of multifunctional energy storages are discussed. Representing an intermediate degree of structural integration, experimental results for a multifunctional energy-storing glass fiber-reinforced composite based on the ceramic electrolyte Li1.4Al0.4Ti1.6(PO43 are presented. Cyclic voltammetry tests are used to characterize the double-layer behavior combined with galvanostatic charge–discharge measurements for capacitance calculation. The capacitance is observed to be unchanged after 1500 charge–discharge cycles revealing a promising potential for future applications. Furthermore, the mechanical properties are assessed by means of four-point bending and tensile tests. Additionally, the influence of mechanical loads on the electrical properties is also investigated, demonstrating the storage stability of the composites.

Triangle bracing system to reduce the vibration level of cooling tower – case study in PT Star Energy Geothermal (Wayang Windu Ltd – Indonesia

Directory of Open Access Journals (Sweden)

Effendi Tri Bahtiar

2018-06-01

Full Text Available Periodical control and measurement revealed that vibration level of motor and gearbox which was supported by Cooling Tower Unit 1 at PT Star Energy Geothermal (Wayang Windu Ltd was significantly increasing since 2013. The vibration was not caused by machinery component failure, but induced by resonance of process flow. Decreasing stiffness of cooling tower structure was suspected causing the increasing vibration level. The physical, chemical, and mechanical properties of wood was deteriorated. The residual strength of the wood had been measured and the data was used to perform dynamic structural analysis on the cooling tower. Several scenarios of structure modification were modelled and drawn, and the best one which the most effectively reducing the vibration level among others was constructed in the field. Triangle inner structure was chosen and applied to modify the cooling tower structure to achieve stiffer and more rigid structure. The vibration level before and after structure modification were measured, and it was proved that the vibration level was significantly reduced after structure modification. Furthermore the cooling tower was not in zone D (danger anymore and the vibration level was accepted according to ISO 10816-3. Keywords: Cooling tower, Dynamic structural analysis, Geothermal power plant, Structural failure, Vibration level

Cosmic structure sizes in generic dark energy models

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, Sourav [Indian Institute of Technology Ropar, Department of Physics, Rupnagar, Punjab (India); Tomaras, Theodore N. [ITCP and Department of Physics, University of Crete, Heraklion (Greece)

2017-08-15

The maximum allowable size of a spherical cosmic structure as a function of its mass is determined by the maximum turn around radius R{sub TA,max}, the distance from its center where the attraction on a radial test particle due to the spherical mass is balanced with the repulsion due to the ambient dark energy. In this work, we extend the existing results in several directions. (a) We first show that, for w ≠ -1, the expression for R{sub TA,max} found earlier, using the cosmological perturbation theory, can be derived using a static geometry as well. (b) In the generic dark energy model with arbitrary time dependent state parameter w(t), taking into account the effect of inhomogeneities upon the dark energy as well, it is shown that the data constrain w(t = today) > -2.3. (c) We address the quintessence and the generalized Chaplygin gas models, both of which are shown to predict structure sizes consistent with observations. (orig.)

The multi-level perspective analysis: Indonesia geothermal energy transition study

Science.gov (United States)

Wisaksono, A.; Murphy, J.; Sharp, J. H.; Younger, P. L.

2018-01-01

The study adopts a multi-level perspective in technology transition to analyse how the transition process in the development of geothermal energy in Indonesia is able to compete against the incumbent fossil-fuelled energy sources. Three levels of multi-level perspective are socio-technical landscape (ST-landscape), socio-technical regime (ST-regime) and niche innovations in Indonesia geothermal development. The identification, mapping and analysis of the dynamic relationship between each level are the important pillars of the multi-level perspective framework. The analysis considers the set of rules, actors and controversies that may arise in the technological transition process. The identified geothermal resource risks are the basis of the emerging geothermal technological innovations in Indonesian geothermal. The analysis of this study reveals the transition pathway, which yields a forecast for the Indonesian geothermal technology transition in the form of scenarios and probable impacts.

Energy levels, lifetimes and radiative data of W LV

Science.gov (United States)

Ding, Xiao-bin; Sun, Rui; Koike, Fumihiro; Murakami, Izumi; Kato, Daiji; Sakaue, Hiroyuki A.; Nakamura, Nobuyuki; Dong, Chen-zhong

2018-01-01

Calculations of energy levels, radiative data and lifetimes are reported for tungsten Ca-like ion (W LV) by using multi-configuration Dirac-Fock (MCDF) method. The GRASP2K package is adopted to carry out a large-scale systematic computation with a restricted active space treatment; the Breit interaction and QED effects are included in subsequent relativistic configuration interaction calculations. The energies and lifetimes of the lowest 119 levels are listed; the main leading configuration of the levels is of the ground state configuration [Ne]3s23p63d2 and the first excited configuration [Ne]3s23p53d3. The wavelengths, radiative rates and oscillator strengths for relatively strong E1, E2, M1, and M2 transitions are listed. Comparisons with earlier experimental and theoretical values are made. The average relative deviations of energy levels from the NIST results and E1 transition wavelengths from the EBIT experimental results have turned to be only 0.20% and 0.13%, respectively. The other present results are in reasonable agreement with available data. These agreements confirm the reliability and accuracy of the current results. The present datasets may help us with the investigation of the electron-electron correlation effects in complex multi-electron highly charged heavy ions and of the diagnosis of tungsten impurity plasmas in fusion science.

The energy distribution structure and dynamic characteristics of energy release in electrostatic discharge process

OpenAIRE

Liu, Qingming; Shao, Huige; Zhang, Yunming

2015-01-01

The detail structure of energy output and the dynamic characteristics of electric spark discharge process have been studied to calculate the energy of electric spark induced plasma under different discharge condition accurately. A series of electric spark discharge experiments were conducted with the capacitor stored energy in the range of 10J 100J and 1000J respectively. And the resistance of wire, switch and plasma between electrodes were evaluated by different methods. An optimized method ...

Review on energy harvesting for structural health monitoring in aeronautical applications

Science.gov (United States)

Le, Minh Quyen; Capsal, Jean-Fabien; Lallart, Mickaël; Hebrard, Yoann; Van Der Ham, Andre; Reffe, Nicolas; Geynet, Lionel; Cottinet, Pierre-Jean

2015-11-01

This paper reviews recent developments in energy harvesting technologies for structural health monitoring (SHM) in aeronautical applications. Aeronautical industries show a great deal of interest in obtaining technologies that can be used to monitor the health of machinery and structures. In particular, the need for self-sufficient monitoring of structures has been ever-increasing in recent years. Autonomous SHM systems typically include embedded sensors, and elements for data acquisition, wireless communication, and energy harvesting. Among all of these components, this paper focuses on energy harvesting technologies. Actually, low-power sensors and wireless communication components are used in newer SHM systems, and a number of researchers have recently investigated such techniques to extract energy from the local environment to power these stand-alone systems. The first part of the paper is dedicated to the different energy sources available in aeronautical applications, i.e., for airplanes and helicopters. The second part gives a presentation of the various devices developed for converting ambient energy into electric power. The last part is dedicated to a comparison of the different technologies and the future development of energy harvesting for aeronautical applications.

Binding free energy analysis of protein-protein docking model structures by evERdock.

Science.gov (United States)

Takemura, Kazuhiro; Matubayasi, Nobuyuki; Kitao, Akio

2018-03-14

To aid the evaluation of protein-protein complex model structures generated by protein docking prediction (decoys), we previously developed a method to calculate the binding free energies for complexes. The method combines a short (2 ns) all-atom molecular dynamics simulation with explicit solvent and solution theory in the energy representation (ER). We showed that this method successfully selected structures similar to the native complex structure (near-native decoys) as the lowest binding free energy structures. In our current work, we applied this method (evERdock) to 100 or 300 model structures of four protein-protein complexes. The crystal structures and the near-native decoys showed the lowest binding free energy of all the examined structures, indicating that evERdock can successfully evaluate decoys. Several decoys that show low interface root-mean-square distance but relatively high binding free energy were also identified. Analysis of the fraction of native contacts, hydrogen bonds, and salt bridges at the protein-protein interface indicated that these decoys were insufficiently optimized at the interface. After optimizing the interactions around the interface by including interfacial water molecules, the binding free energies of these decoys were improved. We also investigated the effect of solute entropy on binding free energy and found that consideration of the entropy term does not necessarily improve the evaluations of decoys using the normal model analysis for entropy calculation.

The policy structure of the Dutch nuclear energy sector

International Nuclear Information System (INIS)

Zijlstra, G.J.

1982-01-01

The main objective of this study has been to indicate the principle structures through which much of governmental nuclear policy is formed and to develop a model for the analysis of policy communication networks. The first chapter begins with a general outline of the international development of nuclear energy and gives an impression of the Dutch nuclear energy sector with special emphasis on the institutional aspects. In chapter II the author elaborates on the place of structural analysis in public policy analysis and argues that it is one of the indispensable elements of public policy analysis. Relations are treated in chapter III. Personal interlocks are given special attention because these are interrelated with financial, informational and other dependency relations and have a special communicative function in public policy-making. The different functions of the interlocks are 'translated' in graph theoretical concepts. Chapter IV introduces a method derived from graph analysis to analyse public policy networks. Several structural configurations are distinguished. In the same chapter an outline of the empirical research on the nuclear energy network will be given. In chapters V and VI the nuclear energy network is analysed, and in chapter VII the decision-making concerning some nuclear items is described in a general way. (Auth.)

Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Nelson, A.J. [Colorado School of Mines, Golden, CO (United States); Berry, G.; Rockett, A. [Univ. of Illinois, Urbana-Champaign, IL (United States)] [and others

1997-04-01

Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe{sub 2}, one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies.

City-Level Energy Decision Making. Data Use in Energy Planning, Implementation, and Evaluation in U.S. Cities

Energy Technology Data Exchange (ETDEWEB)

Aznar, Alexandra [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Day, Megan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Doris, Elizabeth [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mathur, Shivani [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Donohoo-Vallett, Paul [U.S. Department of Energy, Washington, DC (United States)

2015-07-08

The Cities-LEAP technical report, City-Level Energy Decision Making: Data Use in Energy Planning, Implementation, and Evaluation in U.S. Cities, explores how a sample of cities incorporates data into making energy-related decisions. This report provides the foundation for forthcoming components of the Cities-LEAP project that will help cities improve energy decision making by mapping specific city energy or climate policies and actions to measurable impacts and results.

On expectation values for nuclear energy levels

International Nuclear Information System (INIS)

De Wet, J.A.

1978-01-01

The nuclear model is built up by constructing measured states, including the ground state, from the vacuum state. All states are, however, not accessible from the ground state so that selection rules may be found which at the same time impose even more stringent conditions on the labelling of energy levels. These are the subject of this paper

Spin energy levels in axial symmetry: spin 3/2

Energy Technology Data Exchange (ETDEWEB)

de Biasi, R S; Portella, P D [Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Secao de Engenharia e Ciencia dos Materiais

1977-01-01

The spin energy levels in axial symmetry are presented, in graphical and tabular form, for a spin 3/2. The levels are calculated for five different angles between the applied field and the symmetry axis: 0/sup 0/, 30/sup 0/, 45/sup 0/, 60/sup 0/ and 90/sup 0/.

Lamb shift of energy levels in quantum rings

International Nuclear Information System (INIS)

Kryuchkyan, G Yu; Kyriienko, O; Shelykh, I A

2015-01-01

We study the vacuum radiative corrections to energy levels of a confined electron in quantum rings. The calculations are provided for the Lamb shift of energy levels in a low-momentum region of virtual photons and for both one-dimensional and two-dimensional quantum rings. We show that contrary to the well known case of a hydrogen atom the value of the Lamb shift increases with the magnetic momentum quantum number m. We also investigate the dependence of the Lamb shift on magnetic flux piercing the ring and demonstrate a presence of magnetic-flux-dependent oscillations. For a one-dimensional ring the value of the shift strongly depends on the radius of the ring. It is small for semiconductor rings but can attain measurable quantities in natural organic ring-shape molecules, such as benzene, cycloalcanes and porphyrins. (paper)

Energy balance of lactating primiparous sows as affected by feeding level and dietary energy source

NARCIS (Netherlands)

Brand, van den H.; Heetkamp, M.J.W.; Soede, N.M.; Schrama, J.W.; Kemp, B.

2000-01-01

The effects of feeding level and major dietary energy source used during lactation on sow milk composition, piglet body composition, and energy balance of sows were determined. During a 21-d lactation, 48 primiparous sows were fed either a Fat-rich (134.9 g/kg fat; 196.8 g/kg carbohydrate) or a

Electronic structure and formation energy of a vacancy in aluminum

International Nuclear Information System (INIS)

Chakraborty, B.; Siegel, R.W.

1981-11-01

The electronic structure of a vacancy in Al was calculated self-consistently using norm-conserving ionic pseudopotentials obtained from ab initio atomic calculations. A 27-atom-site supercell containing 1 vacancy and 26 atoms was used to simulate the environment of the vacancy. A vacancy formation energy of 1.5 eV was also calculated (cf. the experimental value of 0.66 eV). The effects of the supercell and the nature of the ionic potential on the resulting electronic structure and formation energy are discussed. Results for the electronic structure of a divacancy are also presented. 3 figures

Dark energy and the structure of the Coma cluster of galaxies

Science.gov (United States)

Chernin, A. D.; Bisnovatyi-Kogan, G. S.; Teerikorpi, P.; Valtonen, M. J.; Byrd, G. G.; Merafina, M.

2013-05-01

Context. We consider the Coma cluster of galaxies as a gravitationally bound physical system embedded in the perfectly uniform static dark energy background as implied by ΛCDM cosmology. Aims: We ask if the density of dark energy is high enough to affect the structure of a large and rich cluster of galaxies. Methods: We base our work on recent observational data on the Coma cluster, and apply our theory of local dynamical effects of dark energy, including the zero-gravity radius RZG of the local force field as the key parameter. Results: 1) Three masses are defined that characterize the structure of a regular cluster: the matter mass MM, the dark-energy effective mass MDE (antigravity affects the structure of the Coma cluster strongly at large radii R ≳ 14 Mpc and should be considered when its total mass is derived.

African high-level regional meeting on energy and sustainable development. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Wamukonya, N [UNEP Collaborating Centre on Energy and Environment (Denmark)

2001-07-01

The United Nations Environment Programme (UNEP) jointly with the Government of Kenya and the UN Department for Economic and Social Affairs (DESA) organised the 'African High-Level Regional Meeting on Energy and Sustainable Development' in Januar 2001 at UNEP headquarters in Nairobi, Kenya. The purpose was to support the preparations for CSD 9 and enable African countries to discuss key issues related to energy for sustainable development in their regional context. This report presents the technical statements and papers prepared for the technical workshop. As the reader will quickly notice, the papers reflect the views of the range of experts who participated. Speakers and participants came from ministries or agencies dealing with energy issues, rural development and finance institutions, utilities, private enterprises, NGOs, and research institutions. The papers follow the thermes identified for the CSD 9 session but provide an Africa-specific perspective. In the region, increased access to energy is clearly still a major development issue and has strong links to another key theme - rural energy. A number of papers address these issues from the woodfuel or biomass side, as the majority of the rural population in African countries relies on this energy source and will continue to do so for the foreseeable future. At the same time, improved access to commercial energy forms, particularly through rural electrification programmes, received much attention and several papers present new approaches and experience gained in this area. On the commercial energy supply side the major challenge facing most African countries is the need to reform institutional structures, especially in the power sector. These reforms are generally part of larger economic reform packages promoted by the World Bank, International Monetary Fund, and other financial institutions. In the energy sector the reform process offers an opportunity to introduce more efficiency and competition but it must

Peripheral collisions of heavy ions induced by 40Ar at intermediate energies: giant resonance high energy structures and projectile fragmentation

International Nuclear Information System (INIS)

Blumenfeld, Y.

1987-09-01

The results obtained in similar studies at low incident energies are first of all reviewed. The time of flight spectrometer built for the experiments is then described. A study of the properties of the projectile-like fragments shows numerous deviations from the relativistic energy fragmentation model. Evidence for a strong surface transfer reaction component is given and the persistence of mean field effects at intermediate energies is stressed. A calculation of the contribution of the transfer evaporation mechanism to the inelastic spectra shows that this mechanism is responible for the major part of the background measured at high excitation energy and can in some cases induce narrow structures in the spectra. The inelastic spectra shows a strong excitation of the giant quadrupole resonance. In the region between 20 and 80 MeV excitation energy narrow structures are present for all the studied systems. Statistical and Fourier analysises allow to quantify the probabilities of existence, the widths and the excitation energies of these structures. A transfer evaporation hypothesis cannot consistently reproduce all the observed structures. The excitation energies of the structures can be well described by phenomenological laws where the energies are proportional to the -1/3 power of the target mass. Complete calculations of the excitation probabilities of giant resonances and multiphonon states are performed within a model where the nuclear excitation are calculated microscopically in the Random Phase Approximation. It is shown that a possible interpretation of the structures is the excitation of multiphonon states built with 2 + giant resonances [fr

Structured Innovation of High-Performance Wave Energy Converter Technology: Preprint

Energy Technology Data Exchange (ETDEWEB)

Weber, Jochem W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Laird, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2018-01-25

Wave energy converter (WEC) technology development has not yet delivered the desired commercial maturity nor, and more importantly, the techno-economic performance. The reasons for this have been recognized and fundamental requirements for successful WEC technology development have been identified. This paper describes a multi-year project pursued in collaboration by the National Renewable Energy Laboratory and Sandia National Laboratories to innovate and develop new WEC technology. It specifies the project strategy, shows how this differs from the state-of-the-art approach and presents some early project results. Based on the specification of fundamental functional requirements of WEC technology, structured innovation and systemic problem solving methodologies are applied to invent and identify new WEC technology concepts. Using Technology Performance Levels (TPL) as an assessment metric of the techno-economic performance potential, high performance technology concepts are identified and selected for further development. System performance is numerically modelled and optimized and key performance aspects are empirically validated. The project deliverables are WEC technology specifications of high techno-economic performance technologies of TPL 7 or higher at TRL 3 with some key technology challenges investigated at higher TRL. These wave energy converter technology specifications will be made available to industry for further, full development and commercialisation (TRL 4 - TRL 9).

Energy level alignment at C{sub 60}/DTDCTB/PEDOT:PSS interfaces in organic photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Yoo, Jisu; Jung, Kwanwook; Jeong, Junkyeong; Hyun, Gyeongho [Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Lee, Hyunbok, E-mail: hyunbok@kangwon.ac.kr [Department of Physics, Kangwon National University, Chuncheon-si, Gangwon-do 24341 (Korea, Republic of); Yi, Yeonjin, E-mail: yeonjin@yonsei.ac.kr [Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of)

2017-04-30

Highlights: • The interfacial energy level alignment of C{sub 60}/DTDCTB/PEDOT:PSS was determined via in situ UPS and IPES measurements. • A large photovoltaic gap of 1.30 eV was evaluated between the DTDCTB donor and C{sub 60} acceptor. • A low hole extraction barrier of 0.42 eV from DTDCTB to PEDOT:PSS was evaluated. • The excellent electronic properties of DTDCTB with a narrow band gap were the source of its high OPV power conversion efficiencies. - Abstract: The electronic structure of a narrow band gap small molecule ditolylaminothienyl–benzothiadiazole–dicyanovinylene (DTDCTB), possessing a donor-acceptor-acceptor configuration, was investigated with regard to its application as an efficient donor material in organic photovoltaics (OPVs). The interfacial orbital alignment of C{sub 60}/DTDCTB/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was determined using in situ ultraviolet photoelectron and inverse photoelectron spectroscopic methods. The ionization energy and electron affinity values of DTDCTB were measured to be 5.27 eV and 3.65 eV, respectively, and thus a very small transport gap of 1.62 eV was evaluated. Large band bending of DTDCTB on PEDOT:PSS was observed, resulting in a low hole extraction barrier. Additionally, the photovoltaic gap between the highest occupied molecular orbital level of the DTDCTB donor and the lowest unoccupied molecular orbital level of the C{sub 60} acceptor was estimated to be 1.30 eV, which is known to be the theoretical maximum open-circuit voltage in OPVs employing the C{sub 60}/DTDCTB active layer. The unique electronic structures of DTDCTB contributed toward the recently reported excellent power conversion efficiencies of OPVs containing a DTDCTB donor material.

Sovereignty, Robustness, and Short-Term Energy Security Levels. The Catalonia Case Study

Energy Technology Data Exchange (ETDEWEB)

Rosas-Casals, Martí, E-mail: rosas@mmt.upc.edu [Sustainability Measurement and Modelling Lab, Universitat Politècnica de Catalunya – Barcelona Tech, Barcelona (Spain); Marzo, Mariano [Geomodels Institute, Department of Stratigraphy, Paleontology and Marine Geosciences, University of Barcelona, Barcelona (Spain); Salas-Prat, Pep [Sustainability Measurement and Modelling Lab, Universitat Politècnica de Catalunya – Barcelona Tech, Barcelona (Spain); SmartGrid.cat, Barcelona (Spain)

2014-05-12

Energy-related impacts and conflicts have been used to account for the emergence, maintenance, and collapse of complex societies. On the other hand in the last years, sustainability science has incorporated different frames of reference in order to facilitate the vision of sustainable futures. Most of them suggest that the search for satisfiers of human needs should be rooted on the local (a) construction of organic articulations of people with nature and technology and (b) generation of growing levels of social, economic, and energy self-reliance. This new regional kind of social agreement implies a redefinition of cultural norms and institutions, which at the same time leads toward increased levels of sovereignty for the social group engaged in this process. Sovereignty must not only be understood here in its political sense (as traditionally found in the literature) but also in its technological and energy acceptations. In this paper, we address this last constituent in terms of energy security levels and hierarchy in energy infrastructures between Spain and Catalonia, the latter being a Spanish autonomous community known for its sovereignty aspirations. We show a remarkable difference in energy security levels between both regions, which clearly hinders Catalonia’s capacity to currently achieve a higher level of self-reliance in energetic terms. We suggest that this result is a consequence of the imperfect hierarchy that characterizes energy infrastructures at the spatial scale, and that it can be generalized to all regions where infrastructural systems have been historically assessed and developed under a nationwide planning scheme.

Sovereignty, Robustness, and Short-Term Energy Security Levels. The Catalonia Case Study

International Nuclear Information System (INIS)

Rosas-Casals, Martí; Marzo, Mariano; Salas-Prat, Pep

2014-01-01

Energy-related impacts and conflicts have been used to account for the emergence, maintenance, and collapse of complex societies. On the other hand in the last years, sustainability science has incorporated different frames of reference in order to facilitate the vision of sustainable futures. Most of them suggest that the search for satisfiers of human needs should be rooted on the local (a) construction of organic articulations of people with nature and technology and (b) generation of growing levels of social, economic, and energy self-reliance. This new regional kind of social agreement implies a redefinition of cultural norms and institutions, which at the same time leads toward increased levels of sovereignty for the social group engaged in this process. Sovereignty must not only be understood here in its political sense (as traditionally found in the literature) but also in its technological and energy acceptations. In this paper, we address this last constituent in terms of energy security levels and hierarchy in energy infrastructures between Spain and Catalonia, the latter being a Spanish autonomous community known for its sovereignty aspirations. We show a remarkable difference in energy security levels between both regions, which clearly hinders Catalonia’s capacity to currently achieve a higher level of self-reliance in energetic terms. We suggest that this result is a consequence of the imperfect hierarchy that characterizes energy infrastructures at the spatial scale, and that it can be generalized to all regions where infrastructural systems have been historically assessed and developed under a nationwide planning scheme.

Sovereignty, robustness and short-term energy security levels. The Catalonia case study

Directory of Open Access Journals (Sweden)

Marti eRosas-Casals

2014-05-01

Full Text Available Energy related impacts and conflicts have been used to account for the emergence, maintenance and collapse of complex societies. On the other hand in the last years, sustainability science has incorporated different frames of reference in order to facilitate the vision of sustainable futures. Most of them suggest that the search for satisfiers of human needs should be rooted on the local (a construction of organic articulations of people with nature and technology and (b generation of growing levels of social, economic and energy self-reliance. This new regional kind of social agreement implies a redefinition of cultural norms and institutions, which at the same time leads toward increased levels of sovereignty for the social group engaged in this process. Sovereignty must not only be understood here in its political sense (as traditionally found in the literature but also in its technological and energy acceptations. In this paper we address this last constituent in terms of energy security levels and hierarchy in energy infrastructures between Spain and Catalonia, the latter being a Spanish autonomous community known for its sovereignty aspirations. We show a remarkable difference in energy security levels between both regions which clearly hinders Catalonia’s capacity to currently achieve a higher level of self-reliance in energetic terms. We suggest that this result is a consequence of the imperfect hierarchy that characterize energy infrastructures at the spatial scale, and that it can be generalized to all regions where infrastructural systems have been historically assessed and developed under a nationwide planning scheme.

Topological structures of adiabatic phase for multi-level quantum systems

International Nuclear Information System (INIS)

Liu Zhengxin; Zhou Xiaoting; Liu Xin; Liu Xiongjun; Chen Jingling

2007-01-01

The topological properties of adiabatic gauge fields for multi-level (three-level in particular) quantum systems are studied in detail. Similar to the result that the adiabatic gauge field for SU(2) systems (e.g. two-level quantum system or angular momentum systems, etc) has a monopole structure, the curvature 2-forms of the adiabatic holonomies for SU(3) three-level and SU(3) eight-level quantum systems are shown to have monopole-like (for all levels) or instanton-like (for the degenerate levels) structures

Revisiting drivers of energy intensity in China during 1997–2007: A structural decomposition analysis

International Nuclear Information System (INIS)

Zeng, Lin; Xu, Ming; Liang, Sai; Zeng, Siyu; Zhang, Tianzhu

2014-01-01

The decline of China's energy intensity slowed since 2000. During 2002–2005 it actually increased, reversing the long-term trend. Therefore, it is important to identify drivers of the fluctuation of energy intensity. We use input–output structural decomposition analysis to investigate the contributions of changes in energy mix, sectoral energy efficiency, production structure, final demand structure, and final demand category composition to China's energy intensity fluctuation during 1997–2007. We include household energy consumption in the study by closing the input–output model with respect to households. Results show that sectoral energy efficiency improvements contribute the most to the energy intensity decline during 1997–2007. The increase in China's energy intensity during 2002–2007 is instead explained by changes in final demand composition and production structure. Changes in final demand composition are mainly due to increasing share of exports, while changes in production structure mainly arise from the shift of Chinese economy to more energy-intensive industries. Changes in energy mix and final demand structure contribute little to China's energy intensity fluctuation. From the consumption perspective, growing exports of energy-intensive products and increasing infrastructure demands explain the majority of energy intensity increase during 2002–2007. - Highlights: • We analyzed energy intensity change from production and consumption perspectives. • We extended the research scope of energy intensity to cover household consumption. • Sectoral energy efficiency improvement contributed most to energy intensity decline. • Impact of production structure change on energy intensity varied at different times. • Growing export demand newly became main driver of China's energy intensity increase

An economic prediction of the finer resolution level wavelet coefficients in electronic structure calculations.

Science.gov (United States)

Nagy, Szilvia; Pipek, János

2015-12-21

In wavelet based electronic structure calculations, introducing a new, finer resolution level is usually an expensive task, this is why often a two-level approximation is used with very fine starting resolution level. This process results in large matrices to calculate with and a large number of coefficients to be stored. In our previous work we have developed an adaptively refined solution scheme that determines the indices, where the refined basis functions are to be included, and later a method for predicting the next, finer resolution coefficients in a very economic way. In the present contribution, we would like to determine whether the method can be applied for predicting not only the first, but also the other, higher resolution level coefficients. Also the energy expectation values of the predicted wave functions are studied, as well as the scaling behaviour of the coefficients in the fine resolution limit.

Superconducting magnetic energy storage for electric utility load leveling: A study of cost vs. stored energy

International Nuclear Information System (INIS)

Luongo, C.A.; Loyd, R.J.

1987-01-01

Superconducting Magnetic Energy Storage (SMES) is a promising technology for electric utility load leveling. This paper presents the results of a study to establish the capital cost of SMES as a function of stored energy. Energy-related coil cost and total installed plant cost are given for construction in nominal soil and in competent rock. Economic comparisons are made between SMES and other storage technologies and peaking gas turbines. SMES is projected to be competitive at stored energies as low as 1000 MWh

Investigation of the Structures and Energy Landscapes of Thiocyanate-Water Clusters

Directory of Open Access Journals (Sweden)

Lewis C. Smeeton

2017-03-01

Full Text Available The Basin Hopping search method is used to find the global minima (GM and map the energy landscapes of thiocyanate-water clusters, (SCN−(H2On with 3–50 water molecules, with empirical potentials describing the ion-water and water-water interactions. (It should be noted that beyond n = 23, the lowest energy structures were only found in 1 out of 8 searches so they are unlikely to be the true GM but are indicative low energy structures. As for pure water clusters, the low energy isomers of thiocyanate-water clusters show a preponderance of fused water cubes and pentagonal prisms, with the weakly solvated thiocyanate ion lying on the surface, replacing two water molecules along an edge of a water polyhedron and with the sulfur atom in lower coordinated sites than nitrogen. However, by comparison with Density Functional Theory (DFT calculations, the empirical potential is found to overestimate the strength of the thiocyanate-water interaction, especially O–H⋯S, with low energy DFT structures having lower coordinate N and (especially S atoms than for the empirical potential. In the case of these finite ion-water clusters, the chaotropic (“disorder-making” thiocyanate ion weakens the water cluster structure but the water molecule arrangement is not significantly changed.

Consequences of dietary energy source and energy level on energy balance, lactogenic hormones, and lactation curve characteristics of cows after a short or omitted dry period.

Science.gov (United States)

van Hoeij, R J; Dijkstra, J; Bruckmaier, R M; Gross, J J; Lam, T J G M; Remmelink, G J; Kemp, B; van Knegsel, A T M

2017-10-01

Omitting the dry period (DP) generally reduces milk production in the subsequent lactation. The aim of this study was to evaluate the effect of dietary energy source-glucogenic (G) or lipogenic (L)-and energy level-standard (std) or low-on milk production; energy balance (EB); lactogenic hormones insulin, insulin-like growth factor 1 (IGF-1), and growth hormone (GH); and lactation curve characteristics between wk 1 and 44 postpartum in cows after a 0-d or 30-d DP. Cows (n = 110) were assigned randomly to 3 transition treatments: a 30-d DP with a standard energy level required for expected milk yield [30-d DP(std)], a 0-d DP with the same energy level as cows with a 30-d DP [0-d DP(std)], and a 0-d DP with a low energy level [0-d DP(low)]. In wk 1 to 7, cows were fed the same basal ration but the level of concentrate increased to 6.7 kg/d for cows fed the low energy level and to 8.5 kg/d for cows fed the standard energy level in wk 4. From wk 8 postpartum onward, cows received a G ration (mainly consisting of corn silage and grass silage) or an L ration (mainly consisting of grass silage and sugar beet pulp) with the same energy level contrast (low or std) as in early lactation. Cows fed the G ration had greater milk, lactose, and protein yields, lower milk fat percentage, greater dry matter and energy intakes, and greater plasma IGF-1 concentration compared with cows fed the L ration. Dietary energy source did not affect EB or lactation curve characteristics. In cows with a 0-d DP, the reduced energy level decreased energy intake, EB, and weekly body weight gain, but did not affect milk production or lactation curve characteristics. A 30-d DP resulted in a greater total predicted lactation yield, initial milk yield after calving, peak milk yield, energy intake, energy output in milk, days to conception [only when compared with 0-d DP(low)], plasma GH concentration [only when compared with 0-d DP(std)], and decreased weekly body weight gain compared with a 0-d DP. A

Energy capture and storage in asymmetrically multistable modular structures inspired by skeletal muscle

Science.gov (United States)

Kidambi, Narayanan; Harne, Ryan L.; Wang, K. W.

2017-08-01

The remarkable versatility and adaptability of skeletal muscle that arises from the assembly of its nanoscale cross-bridges into micro-scale assemblies known as sarcomeres provides great inspiration for the development of advanced adaptive structures and material systems. Motivated by the capability of cross-bridges to capture elastic strain energy to improve the energetic efficiency of sudden movements and repeated motions, and by models of cross-bridge power stroke motions and sarcomere contractile behaviors that incorporate asymmetric, bistable potential energy landscapes, this research develops and studies modular mechanical structures that trap and store energy in higher-energy configurations. Modules exhibiting tailorable asymmetric bistability are first designed and fabricated, revealing how geometric parameters influence the asymmetry of the resulting double-well energy landscapes. These experimentally-observed characteristics are then investigated with numerical and analytical methods to characterize the dynamics of asymmetrically bistable modules. The assembly of such modules into greater structures generates complex, multi-well energy landscapes with stable system configurations exhibiting different quantities of stored elastic potential energy. Dynamic analyses illustrate the ability of these structures to capture a portion of the initial kinetic energy due to impulsive excitations as recoverable strain potential energy, and reveal how stiffness parameters, damping, and the presence of thermal noise in micro- and nano-scale applications influence energy capture behaviors. The insights gained could foster the development of advanced structural/material systems inspired by skeletal muscle, including actuators that effectively capture, store, and release energy, as well as adaptive, robust, and reusable armors and protective devices.

Renewable energy projects: structuring a multi-criteria group decision making framework

Energy Technology Data Exchange (ETDEWEB)

Haralambopoulos, D.A.; Polatiidis, H. [UnIversity of the Aegean, Mytilene (Greece). Dept. of Environmental Studies

2003-05-01

This paper describes an applicable group decision-making framework for assisting with multi-criteria analysis in renewable energy projects, utilizing the PROMETHEE II outranking method. The proposed framework is tested in a case study concerning the exploitation of a geothermal resource, located in the island of Chios, Greece. The presented structure provides a serial, decomposed agenda and enhances overall process transparency. Additional, innovatory elements are the incorporation of differing levels of resource exploitation within the decision framework and the direct determination of the PROMETHEE preference thresholds. The developed methodology provides a user-friendly approach, promotes the synergy between different actors, and could pave a way towards consensus. (Author)

DART: A Functional-Level Reconfigurable Architecture for High Energy Efficiency

Directory of Open Access Journals (Sweden)

David Raphaël

2008-01-01

Full Text Available Abstract Flexibility becomes a major concern for the development of multimedia and mobile communication systems, as well as classical high-performance and low-energy consumption constraints. The use of general-purpose processors solves flexibility problems but fails to cope with the increasing demand for energy efficiency. This paper presents the DART architecture based on the functional-level reconfiguration paradigm which allows a significant improvement in energy efficiency. DART is built around a hierarchical interconnection network allowing high flexibility while keeping the power overhead low. To enable specific optimizations, DART supports two modes of reconfiguration. The compilation framework is built using compilation and high-level synthesis techniques. A 3G mobile communication application has been implemented as a proof of concept. The energy distribution within the architecture and the physical implementation are also discussed. Finally, the VLSI design of a 0.13  m CMOS SoC implementing a specialized DART cluster is presented.

DART: A Functional-Level Reconfigurable Architecture for High Energy Efficiency

Directory of Open Access Journals (Sweden)

Sébastien Pillement

2007-12-01

Full Text Available Flexibility becomes a major concern for the development of multimedia and mobile communication systems, as well as classical high-performance and low-energy consumption constraints. The use of general-purpose processors solves flexibility problems but fails to cope with the increasing demand for energy efficiency. This paper presents the DART architecture based on the functional-level reconfiguration paradigm which allows a significant improvement in energy efficiency. DART is built around a hierarchical interconnection network allowing high flexibility while keeping the power overhead low. To enable specific optimizations, DART supports two modes of reconfiguration. The compilation framework is built using compilation and high-level synthesis techniques. A 3G mobile communication application has been implemented as a proof of concept. The energy distribution within the architecture and the physical implementation are also discussed. Finally, the VLSI design of a 0.13 μm CMOS SoC implementing a specialized DART cluster is presented.

ATLAS Level-1 Calorimeter Trigger: Initial Timing and Energy Calibration

CERN Document Server

Childers, J T; The ATLAS collaboration

2010-01-01

The ATLAS Level-1 Calorimeter Trigger identifies high-pT objects in the Liquid Argon and Tile Calorimeters with a fixed latency of ~2.0 µs using a hardware-based, pipelined system built with custom electronics. The Preprocessor Module conditions and digitizes about 7200 pre-summed analogue signals from the calorimeters at the LHC bunch-crossing frequency of 40 MHz, and performs bunch-crossing identification (BCID) and deposited energy measurement for each input signal. This information is passed to further processors for object classification and total energy calculation, and the results used to make the Level-1 trigger decision for the ATLAS detector. The BCID and energy measurement in the trigger depend on precise timing adjustment to achieve correct sampling of the input signal peak. Test pulses from the calorimeters were analysed to derive the initial timing and energy calibration, and first data from the LHC restart in autumn 2009 and early 2010 were used for validation and further optimization. The res...

Analysis of energy intensity in Japan

International Nuclear Information System (INIS)

Okajima, Shigeharu; Okajima, Hiroko

2013-01-01

This study discusses the causes of the increase in Japan's energy intensity, defined as energy consumption divided by GDP, since the early 1990s. The significant reduction in Japan's energy intensity ceased in the early 1980s and has even slightly increased since the early 1990s, indicating that Japan seemingly stopped taking aggressive action to improve energy use. However, further analysis at prefecture level and sector level provides additional insight on energy intensity trends. To analyze the causes of the increase in Japan's energy intensity, energy intensity is decomposed into energy efficiency (improvements in energy efficiency) and energy activity (structural changes from the secondary sector to the tertiary sector of the economy). Our result indicates that the non-uniform energy intensity trends between prefectures are attributed to a high variability in energy efficiency. At sector level, we estimate the income elasticity of energy consumption in each sector and find that a structural change in energy consumption behaviors occurred in all sectors at different time points. The industrial sector and commercial sector became less energy efficient after 1981 and 1988, respectively, which is presumably responsible for the deterioration of Japan's energy intensity since the early 1990s. - Highlights: • We examine why the reduction in Japan's energy intensity increased in the early 1990s. • There is a high variability in energy intensity trends between regions. • The structural changes in energy consumption behaviors occurred in sector level. • These changes may be responsible for the deterioration of Japan's energy intensity

Energy levels of a spin-orbit-coupled Bose-Einstein condensate in a double-well potential

Science.gov (United States)

Wang, Wen-Yuan; Cao, Hui; Zhu, Shi-Liang; Liu, Jie; Fu, Li-Bin

2015-02-01

We investigate the energy levels of a spin-orbit-coupled Bose-Einstein condensate in a double-well potential under the mean-field approximation. We find that the energy levels of the system can be significantly influenced by the atomic interactions. Without atomic interaction, four energy levels change linearly with the tunneling amplitude, the Raman coupling, and the spin-orbit coupling. However, whenever atomic interaction is considered, three more energy levels will appear, which have a nonlinear dependence on those parameters above. These three energy levels are multi-degenerate and related to the macro-symmetry of the system.

Energy levels of a spin–orbit-coupled Bose–Einstein condensate in a double-well potential

International Nuclear Information System (INIS)

Wang, Wen-Yuan; Liu, Jie; Cao, Hui; Fu, Li-Bin; Zhu, Shi-Liang

2015-01-01

We investigate the energy levels of a spin–orbit-coupled Bose–Einstein condensate in a double-well potential under the mean-field approximation. We find that the energy levels of the system can be significantly influenced by the atomic interactions. Without atomic interaction, four energy levels change linearly with the tunneling amplitude, the Raman coupling, and the spin–orbit coupling. However, whenever atomic interaction is considered, three more energy levels will appear, which have a nonlinear dependence on those parameters above. These three energy levels are multi-degenerate and related to the macro-symmetry of the system. (paper)

Electronic structure of xenon implanted with low energy in amorphous silicon

International Nuclear Information System (INIS)

Barbieri, P.F.; Landers, R.; Oliveira, M.H. de; Alvarez, F.; Marques, F.C.

2007-01-01

Electronic structure of Xe implanted in amorphous silicon (a-Si) films are investigated. Xe atoms were implanted with low energy by ion beam assisted deposition (IBAD) technique during growth of the a-Si films. The Xe implantation energy varied in the 0-300 eV energy range. X-ray photoelectron spectroscopy (XPS), X-ray Auger excited spectroscopy (XAES) and X-ray absorption spectroscopy (XAS) were used for investigating the Xe electronic structure. The Xe M 4 N 45 N 45 transitions were measured to extract the Auger parameter and to analyze the initial state and relaxation contributions. It was found that the binding energy variation is mainly due to initial state contribution. The relaxation energy variation also shows that the Xe trapped environment depends on the implantation energy. XAS measurements reveals that Xe atoms are dispersed in the a-Si matrix

Spatial structure, inequality and trading community of renewable energy networks: A comparative study of solar and hydro energy product trades

International Nuclear Information System (INIS)

Fu, Xin; Yang, Yu; Dong, Wen; Wang, Changjian; Liu, Yi

2017-01-01

Renewable energy trade is booming and has formed complicated networks worldwide. However, our knowledge of the spatial structures and evolution of these networks is limited. In this paper, network analyses are used to examine the geographic characteristics of selected renewable energy trades and their evolution based on the United Nations COMTRADE Database from 1988 to 2013. The results show that the networks are expanding to include more and more countries and relationships, and scale of the networks is larger than ever. A tripartite confrontational renewable energy trading system has been forming and is strengthening. Europe, the USA, China and other Asian countries are the main players, and China has overtaken the USA and Europe as the leading player. Inequality and ‘small-world’ characteristics appear in renewable energy trade. Solar energy trade presents a triadic community structure with Europe, the USA and China as the dominant players, while hydro energy trade presents a smaller and more dispersed structure. The core–periphery structure strongly suggests a trade dependency between hubs and peripheral elements in renewable energy trade. Developing countries should design appropriate incentives and contribute to particular segments in renewable energy value chain to accelerate and benefit from the South–South renewable energy trade. - Highlights: • Renewable energy trade networks are identified and analyzed. • Tripartite confrontational renewable energy trade systems have been formed and are strengthening. • Unequal and ‘small world’ characteristics have appeared in the renewable energy trade. • China has overtaken the USA and Europe as the leading player in the renewable energy trade. • Developing countries should make efforts to benefit from the South–South energy trade.

Embodied energy analysis of photovoltaic (PV) system based on macro- and micro-level

International Nuclear Information System (INIS)

Nawaz, I.; Tiwari, G.N.

2006-01-01

In this paper the energy payback time and CO 2 emissions of photovoltaic (PV) system have been analyzed. The embodied energy for production of PV module based on single crystal silicon, as well as for the manufacturing of other system components have been computed at macro- and micro-level assuming irradiation of 800-1200 W/m 2 in different climatic zones in India for inclined surface. The energy payback time with and without balance-of-system for open field and rooftop has been evaluated. It is found that the embodied energy at micro-level is significantly higher than embodied energy at macro-level. The effect of insolation, overall efficiency, lifetime of PV system on energy pay back time and CO 2 emissions have been studied with and without balance of system. A 1.2 kW p PV system of SIEMENS for mudhouse at IIT, Delhi based on macro- and micro-level has been evaluated. The CO 2 mitigation potential, the importance and role of PV system for sustainable development are also highlighted

Lightweight carbon nanotube-based structural-energy storage devices for micro unmanned systems

Science.gov (United States)

Rivera, Monica; Cole, Daniel P.; Hahm, Myung Gwan; Reddy, Arava L. M.; Vajtai, Robert; Ajayan, Pulickel M.; Karna, Shashi P.; Bundy, Mark L.

2012-06-01

There is a strong need for small, lightweight energy storage devices that can satisfy the ever increasing power and energy demands of micro unmanned systems. Currently, most commercial and developmental micro unmanned systems utilize commercial-off-the-shelf (COTS) lithium polymer batteries for their energy storage needs. While COTS lithium polymer batteries are the industry norm, the weight of these batteries can account for up to 60% of the overall system mass and the capacity of these batteries can limit mission durations to the order of only a few minutes. One method to increase vehicle endurance without adding mass or sacrificing payload capabilities is to incorporate multiple system functions into a single material or structure. For example, the body or chassis of a micro vehicle could be replaced with a multifunctional material that would serve as both the vehicle structure and the on-board energy storage device. In this paper we present recent progress towards the development of carbon nanotube (CNT)-based structural-energy storage devices for micro unmanned systems. Randomly oriented and vertically aligned CNT-polymer composite electrodes with varying degrees of flexibility are used as the primary building blocks for lightweight structural-supercapacitors. For the purpose of this study, the mechanical properties of the CNT-based electrodes and the charge-discharge behavior of the supercapacitor devices are examined. Because incorporating multifunctionality into a single component often degrades the properties or performance of individual structures, the performance and property tradeoffs of the CNT-based structural-energy storage devices will also be discussed.

Structural and operational optimisation of distributed energy systems

International Nuclear Information System (INIS)

Soederman, Jarmo; Pettersson, Frank

2006-01-01

A distributed energy system (DES) is a system comprising a set of energy suppliers and consumers, district heating pipelines, heat storage facilities and power transmission lines in a region. Distributed energy production has got an increasingly important role in the energy market. In this paper, a model for structural and operational optimisation of DES is presented. In the model, production and consumption of electrical power and heat, power transmissions, transport of fuels to the production plants, transport of water in the district heating pipelines and storage of heat are taken into account. The problem is formulated as a mixed integer linear programming (MILP) problem where the objective is to minimise the overall cost of DES, i.e., the sum of the running costs for the included operations and the annualised investment costs of the included equipment. An illustrative example is presented for a complex DES situation. The solution gives the DES structure, i.e., which production units, heat transport lines and storages should be built as well as their locations be, together with design parameters for plants and pipelines. The model enables the involved parties-suppliers, consumers, designers and authorities-to form a joint view of different situations as a basis for the decision making. A tool based on the model is built, which can be used in design, in creating guidelines for regional energy policies and for versatile what-if analyses

Energy level diagrams for black hole orbits

Science.gov (United States)

Levin, Janna

2009-12-01

A spinning black hole with a much smaller black hole companion forms a fundamental gravitational system, like a colossal classical analog to an atom. In an appealing if imperfect analogy with atomic physics, this gravitational atom can be understood through a discrete spectrum of periodic orbits. Exploiting a correspondence between the set of periodic orbits and the set of rational numbers, we are able to construct periodic tables of orbits and energy level diagrams of the accessible states around black holes. We also present a closed-form expression for the rational q, thereby quantifying zoom-whirl behavior in terms of spin, energy and angular momentum. The black hole atom is not just a theoretical construct, but corresponds to extant astrophysical systems detectable by future gravitational wave observatories.

Energy level diagrams for black hole orbits

International Nuclear Information System (INIS)

Levin, Janna

2009-01-01

A spinning black hole with a much smaller black hole companion forms a fundamental gravitational system, like a colossal classical analog to an atom. In an appealing if imperfect analogy with atomic physics, this gravitational atom can be understood through a discrete spectrum of periodic orbits. Exploiting a correspondence between the set of periodic orbits and the set of rational numbers, we are able to construct periodic tables of orbits and energy level diagrams of the accessible states around black holes. We also present a closed-form expression for the rational q, thereby quantifying zoom-whirl behavior in terms of spin, energy and angular momentum. The black hole atom is not just a theoretical construct, but corresponds to extant astrophysical systems detectable by future gravitational wave observatories.

Knot soliton in DNA and geometric structure of its free-energy density.

Science.gov (United States)

Wang, Ying; Shi, Xuguang

2018-03-01

In general, the geometric structure of DNA is characterized using an elastic rod model. The Landau model provides us a new theory to study the geometric structure of DNA. By using the decomposition of the arc unit in the helical axis of DNA, we find that the free-energy density of DNA is similar to the free-energy density of a two-condensate superconductor. By using the φ-mapping topological current theory, the torus knot soliton hidden in DNA is demonstrated. We show the relation between the geometric structure and free-energy density of DNA and the Frenet equations in differential geometry theory are considered. Therefore, the free-energy density of DNA can be expressed by the curvature and torsion of the helical axis.

Configurations and level structure of 219Rn

International Nuclear Information System (INIS)

Sheline, R.K.; Liang, C.F.; Paris, P.

1998-01-01

The level structure of 219 Rn has been studied using the alpha decay of 223 Ra and coincident gamma rays. While only modest changes are required in the level structure, and only above 342.8 keV, severe changes are required throughout the level scheme in the spin assigments. These changes allow the assignment of two sets of anomalous bands with K=5/2 ± and K=3/2 ± . The K=5/2 ± bands have configurations intermediate between the reflection asymmetric configuration and the g 9/2 shell model configuration, while the K=3/2 ± bands have configurations intermediate between the mixed reflection asymmetric configuration and the i 11/2 shell model configuration. Comparison of the systematics of 219 Rn with neighboring isotones, isobars, and isotopes shows clearly the collapse of the quadrupole-octupole-type configurations into the less degenerate shell model configurations. copyright 1998 The American Physical Society

New energy levels of atomic niobium (Nb I) discovered by laser-spectroscopic investigations

Science.gov (United States)

Kröger, S.; Windholz, L.; Başar, Gü.; Başar, Gö.

2018-06-01

We report the discovery of 9 previously unknown energy levels of the atomic niobium, all having even parity. Two levels have energies below 19,500 cm-1 and angular momentum J = 3/2, while the energies of the others are located between 39,700 and 43,420 cm-1. The levels were discovered by laser excitation of several unclassified spectral lines in the wavelength range between 554 nm and 650 nm and detection of laser-induced fluorescence with a monochromator.

Energy levels distribution in supersaturated silicon with titanium for photovoltaic applications

Energy Technology Data Exchange (ETDEWEB)

Pérez, E., E-mail: eduper@ele.uva.es; Castán, H.; García, H.; Dueñas, S.; Bailón, L. [Dept. de Electricidad y Electrónica, Universidad de Valladolid, ETSI Telecomunicación, Paseo de Belén 15, 47011 Valladolid (Spain); Montero, D.; García-Hernansanz, R.; García-Hemme, E.; González-Díaz, G. [Dept. de Física Aplicada III (Electricidad y Electrónica), Univ. Complutense de Madrid, 28040 Madrid (Spain); CEI Campus Moncloa, UCM-UPM, 28040 Madrid (Spain); Olea, J. [CEI Campus Moncloa, UCM-UPM, 28040 Madrid (Spain); Instituto de Energía Solar, E.T.S.I. de Telecomunicación, Univ. Politécnica de Madrid, 28040 Madrid (Spain)

2015-01-12

In the attempt to form an intermediate band in the bandgap of silicon substrates to give it the capability to absorb infrared radiation, we studied the deep levels in supersaturated silicon with titanium. The technique used to characterize the energy levels was the thermal admittance spectroscopy. Our experimental results showed that in samples with titanium concentration just under Mott limit there was a relationship among the activation energy value and the capture cross section value. This relationship obeys to the well known Meyer-Neldel rule, which typically appears in processes involving multiple excitations, like carrier capture/emission in deep levels, and it is generally observed in disordered systems. The obtained characteristic Meyer-Neldel parameters were Tmn = 176 K and kTmn = 15 meV. The energy value could be associated to the typical energy of the phonons in the substrate. The almost perfect adjust of all experimental data to the same straight line provides further evidence of the validity of the Meyer Neldel rule, and may contribute to obtain a deeper insight on the ultimate meaning of this phenomenon.

Energy levels distribution in supersaturated silicon with titanium for photovoltaic applications

International Nuclear Information System (INIS)

Pérez, E.; Castán, H.; García, H.; Dueñas, S.; Bailón, L.; Montero, D.; García-Hernansanz, R.; García-Hemme, E.; González-Díaz, G.; Olea, J.

2015-01-01

In the attempt to form an intermediate band in the bandgap of silicon substrates to give it the capability to absorb infrared radiation, we studied the deep levels in supersaturated silicon with titanium. The technique used to characterize the energy levels was the thermal admittance spectroscopy. Our experimental results showed that in samples with titanium concentration just under Mott limit there was a relationship among the activation energy value and the capture cross section value. This relationship obeys to the well known Meyer-Neldel rule, which typically appears in processes involving multiple excitations, like carrier capture/emission in deep levels, and it is generally observed in disordered systems. The obtained characteristic Meyer-Neldel parameters were Tmn = 176 K and kTmn = 15 meV. The energy value could be associated to the typical energy of the phonons in the substrate. The almost perfect adjust of all experimental data to the same straight line provides further evidence of the validity of the Meyer Neldel rule, and may contribute to obtain a deeper insight on the ultimate meaning of this phenomenon

RNA secondary structure prediction with pseudoknots: Contribution of algorithm versus energy model.

Science.gov (United States)

Jabbari, Hosna; Wark, Ian; Montemagno, Carlo

2018-01-01

RNA is a biopolymer with various applications inside the cell and in biotechnology. Structure of an RNA molecule mainly determines its function and is essential to guide nanostructure design. Since experimental structure determination is time-consuming and expensive, accurate computational prediction of RNA structure is of great importance. Prediction of RNA secondary structure is relatively simpler than its tertiary structure and provides information about its tertiary structure, therefore, RNA secondary structure prediction has received attention in the past decades. Numerous methods with different folding approaches have been developed for RNA secondary structure prediction. While methods for prediction of RNA pseudoknot-free structure (structures with no crossing base pairs) have greatly improved in terms of their accuracy, methods for prediction of RNA pseudoknotted secondary structure (structures with crossing base pairs) still have room for improvement. A long-standing question for improving the prediction accuracy of RNA pseudoknotted secondary structure is whether to focus on the prediction algorithm or the underlying energy model, as there is a trade-off on computational cost of the prediction algorithm versus the generality of the method. The aim of this work is to argue when comparing different methods for RNA pseudoknotted structure prediction, the combination of algorithm and energy model should be considered and a method should not be considered superior or inferior to others if they do not use the same scoring model. We demonstrate that while the folding approach is important in structure prediction, it is not the only important factor in prediction accuracy of a given method as the underlying energy model is also as of great value. Therefore we encourage researchers to pay particular attention in comparing methods with different energy models.

The effects of uranium oxide high-level waste on the structure of iron phosphate glasses

International Nuclear Information System (INIS)

Badyal, Y.

1998-01-01

Because of their unusually good chemical durability, iron phosphate glasses are a natural candidate for a nuclear waste disposal glass. We have studied the effects of UO 2 high-level waste on the structure of iron phosphate glasses with both neutron and high-energy x-ray diffraction using the GLAD instrument of the Intense Pulsed Neutron Source and the 1-BM bending magnet beamline of the Advanced Photon Source, respectively. The results of neutron scattering, which is mostly sensitive to correlations involving light atoms i.e. O-O, Fe-O and P-O, suggest the main structural features of the base glass are largely unaffected by the addition of UO 2 . The nearest-neighbor P-O, Fe-O and O-O peaks remain at the same position in real space and their intensities scale approximately with concentration. These findings are consistent with the earlier results of Raman scattering and EXAFS on the Fe-K edge wherein both cases the spectra remain similar to the base glass. High-energy x-ray scattering which is sensitive to correlations involving the heavier atoms and thus complements the neutron measurements, is also consistent with uranium occupying interstitial sites in the relatively undisturbed base glass structure. However, important questions remain as to the precise local structure and oxidation state of uranium in these glasses

Energy levels of one-dimensional systems satisfying the minimal length uncertainty relation

Energy Technology Data Exchange (ETDEWEB)

Bernardo, Reginald Christian S., E-mail: rcbernardo@nip.upd.edu.ph; Esguerra, Jose Perico H., E-mail: jesguerra@nip.upd.edu.ph

2016-10-15

The standard approach to calculating the energy levels for quantum systems satisfying the minimal length uncertainty relation is to solve an eigenvalue problem involving a fourth- or higher-order differential equation in quasiposition space. It is shown that the problem can be reformulated so that the energy levels of these systems can be obtained by solving only a second-order quasiposition eigenvalue equation. Through this formulation the energy levels are calculated for the following potentials: particle in a box, harmonic oscillator, Pöschl–Teller well, Gaussian well, and double-Gaussian well. For the particle in a box, the second-order quasiposition eigenvalue equation is a second-order differential equation with constant coefficients. For the harmonic oscillator, Pöschl–Teller well, Gaussian well, and double-Gaussian well, a method that involves using Wronskians has been used to solve the second-order quasiposition eigenvalue equation. It is observed for all of these quantum systems that the introduction of a nonzero minimal length uncertainty induces a positive shift in the energy levels. It is shown that the calculation of energy levels in systems satisfying the minimal length uncertainty relation is not limited to a small number of problems like particle in a box and the harmonic oscillator but can be extended to a wider class of problems involving potentials such as the Pöschl–Teller and Gaussian wells.

Energy efficient structure-free data aggregation and delivery in WSN

Directory of Open Access Journals (Sweden)

Prabhudutta Mohanty

2016-11-01

Full Text Available In Wireless Sensor Networks (WSNs, the energy consumption due to the sensed data transmission is more than processing data locally within the sensor node. The data aggregation is one of the techniques to conserve energy by eliminating the redundant data transmission in dense WSNs. In this paper, we propose an energy efficient structure-free data aggregation and delivery (ESDAD protocol, which aggregates the redundant data in the intermediate nodes. In the proposed protocol, waiting time for packets at each intermediate node is calculated very sensibly so that data can be aggregated efficiently in the routing path. The sensed data packets are transmitted judicially to the aggregation point for data aggregation. The ESDAD protocol computes a cost function for structure-free, next-hop node selection and performs near source data aggregation. The buffer of each node is partitioned to maintain different types of flows for fair and efficient data delivery. The transmission rates of the sources and intermediate nodes are adjusted during congestion. The performance of the proposed protocol is evaluated through extensive simulations. The simulation results reveal that it outperforms the existing structure-free protocols in terms of energy efficiency, reliability and on-time delivery ratio.

Crystal structure representations for machine learning models of formation energies

Energy Technology Data Exchange (ETDEWEB)

Faber, Felix [Department of Chemistry, Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials, University of Basel Switzerland; Lindmaa, Alexander [Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping Sweden; von Lilienfeld, O. Anatole [Department of Chemistry, Institute of Physical Chemistry and National Center for Computational Design and Discovery of Novel Materials, University of Basel Switzerland; Argonne Leadership Computing Facility, Argonne National Laboratory, 9700 S. Cass Avenue Lemont Illinois 60439; Armiento, Rickard [Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping Sweden

2015-04-20

We introduce and evaluate a set of feature vector representations of crystal structures for machine learning (ML) models of formation energies of solids. ML models of atomization energies of organic molecules have been successful using a Coulomb matrix representation of the molecule. We consider three ways to generalize such representations to periodic systems: (i) a matrix where each element is related to the Ewald sum of the electrostatic interaction between two different atoms in the unit cell repeated over the lattice; (ii) an extended Coulomb-like matrix that takes into account a number of neighboring unit cells; and (iii) an ansatz that mimics the periodicity and the basic features of the elements in the Ewald sum matrix using a sine function of the crystal coordinates of the atoms. The representations are compared for a Laplacian kernel with Manhattan norm, trained to reproduce formation energies using a dataset of 3938 crystal structures obtained from the Materials Project. For training sets consisting of 3000 crystals, the generalization error in predicting formation energies of new structures corresponds to (i) 0.49, (ii) 0.64, and (iii) 0.37eV/atom for the respective representations.

Spinless Salpeter equation: Laguerre bounds on energy levels

International Nuclear Information System (INIS)

Lucha, W.; Schoeberl, F.F.

1996-08-01

The spinless Salpeter equation may be considered either as a standard approximation to the Bethe-Salpeter formalism, designed for the description of bound states within a relativistic quantum field theory, or as the most simple, to a certain extent relativistic generalization of the customary non relativistic Schroedinger formalism. Because of the presence of the rather difficult-to-handle square-root operator of the relativistic kinetic energy in the corresponding Hamiltonian, very frequently the corresponding (discrete) spectrum of energy eigenvalues cannot be determined analytically. Therefore, we show how to calculate, by some clever choice of basis vectors in the Hilbert space of solutions, for the rather large class of power-law potentials, at least (sometimes excellent) upper bounds on these energy eigenvalues, for the lowest-lying levels this even analytically. (author)

Impact of energy policy instruments on the estimated level of underlying energy efficiency in the EU residential sector

International Nuclear Information System (INIS)

Filippini, Massimo; Hunt, Lester C.; Zorić, Jelena

2014-01-01

The promotion of energy efficiency is seen as one of the top priorities of EU energy policy (EC, 2010). In order to design and implement effective energy policy instruments, it is necessary to have information on energy demand price and income elasticities in addition to sound indicators of energy efficiency. This research combines the approaches taken in energy demand modelling and frontier analysis in order to econometrically estimate the level of energy efficiency for the residential sector in the EU-27 member states for the period 1996 to 2009. The estimates for the energy efficiency confirm that the EU residential sector indeed holds a relatively high potential for energy savings from reduced inefficiency. Therefore, despite the common objective to decrease ‘wasteful’ energy consumption, considerable variation in energy efficiency between the EU member states is established. Furthermore, an attempt is made to evaluate the impact of energy-efficiency measures undertaken in the EU residential sector by introducing an additional set of variables into the model and the results suggest that financial incentives and energy performance standards play an important role in promoting energy efficiency improvements, whereas informative measures do not have a significant impact. - Highlights: • The level of energy efficiency of the EU residential sector is estimated. • Considerable potential for energy savings from reduced inefficiency is established. • The impact of introduced energy-efficiency policy measures is also evaluated. • Financial incentives are found to promote energy efficiency improvements. • Energy performance standards also play an important role

On-Site Renewable Energy and Green Buildings: A System-Level Analysis.

Science.gov (United States)

Al-Ghamdi, Sami G; Bilec, Melissa M

2016-05-03

Adopting a green building rating system (GBRSs) that strongly considers use of renewable energy can have important environmental consequences, particularly in developing countries. In this paper, we studied on-site renewable energy and GBRSs at the system level to explore potential benefits and challenges. While we have focused on GBRSs, the findings can offer additional insight for renewable incentives across sectors. An energy model was built for 25 sites to compute the potential solar and wind power production on-site and available within the building footprint and regional climate. A life-cycle approach and cost analysis were then completed to analyze the environmental and economic impacts. Environmental impacts of renewable energy varied dramatically between sites, in some cases, the environmental benefits were limited despite the significant economic burden of those renewable systems on-site and vice versa. Our recommendation for GBRSs, and broader policies and regulations, is to require buildings with higher environmental impacts to achieve higher levels of energy performance and on-site renewable energy utilization, instead of fixed percentages.

Spectrum and energy levels of five-times-ionized niobium (Nb VI)

International Nuclear Information System (INIS)

Ekberg, J.O.; Reader, J.

1994-01-01

The spectrum of the kryptonlike ion Nb VI was observed from 325 to 2700 with sliding-spark discharges on 10.7-m normal-incidence and grazing-incidence spectrographs. Experimental energies were determined for all levels of the 4s 2 4p 6 , 4s 2 4p 5 4d, 4f, 5s, 5p, 5d, 5g, 6s, and 4s4p 6 4d configurations as well as for some levels of the 4s 2 4p 5 6g and 6h configurations. A total of 303 lines are now classified as transitions between 99 observed levels. Large hyperfine splittings were found for several levels of the 4p 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. An improved value of the ionization energy was determined from the 4p 5 5g, 6g, and 6h configurations. The adopted value of the limit is 823 240 ± 50 cm - 1 (102.069 ± 0.006 eV)

Political and economic structure and energy industry status of Australia

Energy Technology Data Exchange (ETDEWEB)

Bang, K.Y. [Korea Energy Economics Institute, Euiwang (Korea, Republic of)

1998-06-01

Looking at the composition of energy resources import of Korea per each country, Australian-made import takes up 11.8% of total energy resources import. It possesses the highest import composition of 30.5% when petroleum sector is excluded. In the order of Korea`s mineral import per each country, Australia still keep the number one position every year though Korea keep promoting the diversification of import sources. In the mean time, reflecting on the treatment aspect of import country of Australia, when Korea`s energy, the import size of resources, import intensity of Australia`s primary raw material resources and international resources situation are considered, Korea is thought to receive less treatment from Australia as the second export country of Australia than Japan who is the number one export country of Australia, relatively. Though the increase ratio of Korean tourists in Australia is the highest for the past few years and international promotion effect shows big with the IMF financial support of Korea who faces sudden economic crisis recently as a momentum, sincere evaluation through in-depth analysis between Korea and Australia is still in the initial stage. The necessity to diagnosis the general political and economic structure of Australia more in detail emerges as trade volume between two countries keep growing, esp. in the import of energy and resources sectors, the number of visits between two countries keep increasing. Therefore, the purpose of this study lies mainly in the structure of the new Australian government, general macroeconomics structure and the understanding of energy industry-related status such as energy supply and demand, development status of energy, related laws, and government`s energy agencies, etc. 6 refs., 3 figs., 22 tabs.

Active pipe-embedded structures in buildings for utilizing low-grade energy sources: A review

International Nuclear Information System (INIS)

Xu, Xinhua; Wang, Jinbo; Wang, Shengwei; Xiao, Fu

2010-01-01

Low-grade energy sources such as geothermal energy, favorable ambient air and industrial waste heat etc. exist widely. Sufficient utilization of these low-grade energy sources may reduce our daily dependence on high-grade energy sources such as electricity resulting in reduced emission of green house gas for environmental conservation. Active pipe-embedded structure as floor/ceiling usually with water as the medium to carry heat or coolth may utilize these low-grade energy sources for providing space air-conditioning. Compact arrangement of pipes in the structure may significantly enlarge heat transfer surface between the slab mass and water in the pipe allowing substantial heat flows even for relatively small temperature differences. Application of the heat or coolth storage capacity of this structure for preheating or pre-cooling is also one among the advantages of this structure for shifting load and exploiting the nighttime cheap electricity tariff in some regions. This paper presents the technology of the active pipe-embedded structure for utilizing widely existing low-grade energy sources following by a comprehensive review on the heat transfer calculation models of this structure and its practical applications in real building systems for space air-conditioning. This review shows that more works on the active structure, especially simple and transient models for dynamic and accurate performance prediction and easy integration with existing building energy simulation packages, are worthwhile for further promoting the practical application wherever the low-grade energy sources are favorable. (author)

The effect of seismic energy scavenging on host structure and harvesting performance

International Nuclear Information System (INIS)

Lallart, Mickaël; Wu, Yi-Chieh; Yan, Linjuan; Richard, Claude; Guyomar, Daniel

2013-01-01

Cantilevered piezoelectric energy harvesters have been studied extensively in recent years. Numerous techniques have been investigated to achieve optimal power output. However, the extraction of electrical energy from mechanical vibration leads to a reduction of the vibration magnitude of the harvester because of the electromechanical coupling effect, and so a model considering constant vibration magnitude input is no longer valid. Thus, an energy harvesting model excited with a constant force or acceleration magnitude has been adopted to take into account the damping effect induced by the energy harvesting process. This paper extends this model to the effect of energy harvesting on the fixed host structure (mechanical to mechanical coupling). Theoretical developments are presented as a dynamic problem of an electromechanically coupled two-degree-of-freedom (TDOF) spring–mass–damper system. Then, experimental measurements and computations based on finite element modeling (FEM) are carried out to validate theoretical predictions. It is shown that the extracted power obtained from the TDOF model would reach a maximal value by tuning the mass ratio between the host structure and the harvester and optimizing the electric load. The mechanical to mechanical coupling effect due to the harvester leads to a trade-off between the mechanical energy of the host structure and the harvested energy. When the harvester mass to host structure mass ratio is around 10 −3 , the maximal power is obtained and the host structure then has a sudden displacement reduction due to the strong mechanical to mechanical coupling. Experimental measurements have been performed for a mass ratio of around 0.02, with which the harvester effect is not negligible on the host structure behavior as the host structure displacement shows a decrease of more than 3 dB. In addition, the harvested power calculated with the TDOF model is about two times less than with a single-degree-of-freedom (SDOF

Observation of Cd 4d95s25p J=3 autoionizing levels in (e,2e) energy spectra

International Nuclear Information System (INIS)

Martin, N.L.S.; Bauman, R.P.; Wilson, M.

1998-01-01

Cadmium (e,2e) energy spectra have been measured for kinematics corresponding to a momentum transfer of 1 a.u. Two previously unknown cadmium autoinizing levels have been observed. Their energies are in excellent agreement with existing ab initio structure calculations of the 4d 9 5s 2 5p J=3 levels. One level is easily seen at an ejected-electron direction along the momentum-transfer axis, but is absent for a direction 39 degree away from this axis. The opposite is true for the other level; it is absent in the former, but present in the latter case. This behavior is in agreement with a calculation that takes into account that the J=3 levels can autoionize into both singlet and triplet 5sEf continua. The intensity of the new levels, relative to the well-known 4d 9 5s 2 5p J=1 levels, agrees well with a plane-wave Born approximation calculation for the J=3 levels. The third 4d 9 5s 2 5p J=3 level is calculated to lie within the broad 4d 9 5s 2 5p 1 P 1 level and cannot be seen in the present experiments. copyright 1998 The American Physical Society

Sparse RNA folding revisited: space-efficient minimum free energy structure prediction.

Science.gov (United States)

Will, Sebastian; Jabbari, Hosna

2016-01-01

RNA secondary structure prediction by energy minimization is the central computational tool for the analysis of structural non-coding RNAs and their interactions. Sparsification has been successfully applied to improve the time efficiency of various structure prediction algorithms while guaranteeing the same result; however, for many such folding problems, space efficiency is of even greater concern, particularly for long RNA sequences. So far, space-efficient sparsified RNA folding with fold reconstruction was solved only for simple base-pair-based pseudo-energy models. Here, we revisit the problem of space-efficient free energy minimization. Whereas the space-efficient minimization of the free energy has been sketched before, the reconstruction of the optimum structure has not even been discussed. We show that this reconstruction is not possible in trivial extension of the method for simple energy models. Then, we present the time- and space-efficient sparsified free energy minimization algorithm SparseMFEFold that guarantees MFE structure prediction. In particular, this novel algorithm provides efficient fold reconstruction based on dynamically garbage-collected trace arrows. The complexity of our algorithm depends on two parameters, the number of candidates Z and the number of trace arrows T; both are bounded by [Formula: see text], but are typically much smaller. The time complexity of RNA folding is reduced from [Formula: see text] to [Formula: see text]; the space complexity, from [Formula: see text] to [Formula: see text]. Our empirical results show more than 80 % space savings over RNAfold [Vienna RNA package] on the long RNAs from the RNA STRAND database (≥2500 bases). The presented technique is intentionally generalizable to complex prediction algorithms; due to their high space demands, algorithms like pseudoknot prediction and RNA-RNA-interaction prediction are expected to profit even stronger than "standard" MFE folding. SparseMFEFold is free

Application of lightweight materials in structure concept design of large-scale solar energy unmanned aerial vehicle

Science.gov (United States)

Zhang, Wei; Lv, Shengli; Guan, XiQi

2017-09-01

Carbon fiber composites and film materials can be effectively used in light aircraft structures, especially for solar unmanned aerial vehicles. The use of light materials can reduce the weight of the aircraft, but also can effectively improve the aircraft's strength and stiffness. The structure of the large aspect ratio solar energy UAV was analyzed in detail, taking Solar-impulse solar aircraft as an example. The solar energy UAV has a wing aspect ratio greater than 20, and the detailed digital model of the wing structure including beam, ribs and skin was built, also the Finite Element Method was applied to analyze the static and dynamic performance of the structure. The upper skin of the wing is covered with silicon solar cells, while the lower skin is light and transparent film. The single beam truss form of carbon fiber lightweight material is used in the wing structure. The wing beam is a box beam with rectangular cross sections. The box beam connected the front parts and after parts of the ribs together. The fuselage of the aircraft was built by space truss structure. According to the static and dynamic analysis with Finite Element method, it was found that the aircraft has a small wingtip deflection relative to the wingspan in the level flight state. The first natural frequency of the wing structure is pretty low, which is closed to the gust load.

Towards Flexibility Detection in Device-Level Energy Consumption

DEFF Research Database (Denmark)

Neupane, Bijay; Pedersen, Torben Bach; Thiesson, Bo

2014-01-01

The increasing drive towards green energy has boosted the installation of Renewable Energy Sources (RES). Increasing the share of RES in the power grid requires demand management by flexibility in the consumption. In this paper, we perform a state-of-the-art analysis on the flexibility and operat......The increasing drive towards green energy has boosted the installation of Renewable Energy Sources (RES). Increasing the share of RES in the power grid requires demand management by flexibility in the consumption. In this paper, we perform a state-of-the-art analysis on the flexibility...... and operation patterns of the devices in a set of real households. We propose a number of specific pre-processing steps such as operation stage segmentation, and aberrant operation duration removal to clean device level data. Further, we demonstrate various device operation properties such as hourly and daily...... regularities and patterns and the correlation between operating different devices. Subsequently, we show the existence of detectable time and energy flexibility in device operations. Finally, we provide various results providing a foundation for load- and flexibility-detection and -prediction at the device...

Ultrahigh energy nuclei propagation in a structured, magnetized universe

International Nuclear Information System (INIS)

Armengaud, Eric; Sigl, Guenter; Miniati, Francesco

2005-01-01

We compare the propagation of iron and proton nuclei above 10 19 eV in a structured Universe with source and magnetic field distributions obtained from a large-scale structure simulation and source densities ∼10 -5 Mpc -3 . All relevant cosmic ray interactions are taken into account, including photo-disintegration and propagation of secondary products. Iron injection predicts spectral shapes different from proton injection which disagree with existing data below ≅30 EeV. Injection of light nuclei or protons must therefore contribute at these energies. However, at higher energies, existing data are consistent with injection of pure iron with spectral indices between ∼2 and ∼2.4. This allows a significant recovery of the spectrum above ≅100 EeV, especially in the case of large deflections. Significant autocorrelation and anisotropy, and considerable cosmic variance are also predicted in this energy range. The mean atomic mass fluctuates considerably between different scenarios. At energies below 60 EeV, if the observed A > or approx. 35, magnetic fields must have a negligible effect on propagation. At the highest energies the observed flux will be dominated by only a few sources whose location may be determined by next generation experiments to within 10-20 deg. even if extra-galactic magnetic fields are important

Energy structure, marginal efficiency and substitution rate: An empirical study of China

International Nuclear Information System (INIS)

Han Zhiyong; Fan Ying; Jiao Jianling; Yan Jisheng; Wei Yiming

2007-01-01

Energy efficiency is an important factor in developing energy policies as it represents the extent to which resources support economic output. In recent literature, relevant studies have mainly focused on aggregate energy efficiency, but rarely touched on the marginal efficiency of diverse energy resources and their comparative substitution rate. During 1978-2003, China's energy efficiency continually increased; and consequently became a hot topic in contemporary literature. However, there is no empirical study on the relationship between energy structure and energy efficiency. In order to close the gap, this paper reports the empirical study of the impact of China's energy structure on its energy efficiency from 1978 to 2003. The work covered primary estimation of the marginal efficiency of coal and petroleum in China, as well as the comparative substitution rate. Results indicate that the substitution rate between petroleum and coal is a factor of 5.38

Project of the electron linear accelerator on the biperiodical accelerating structure with deep energy retuning in a pulse mode

International Nuclear Information System (INIS)

Bogdanovich, B.Yu.; Zavadtsev, D.A.; Kaminskij, V.I.; Sobenin, N.P.; Fadin, A.I.; Zavadtsev, A.A.

2001-01-01

The schemes of the electron linear accelerator (ELA), realized on the basis of a biperiodical accelerating structure and ensuring the possibility of deep retuning of the beam energy in a pulse mode, are considered. Advantages and shortcomings of the proposed methods of pulse regulation of the electron energy are discussed. A project of a two-section ELA with two levels of energy (10 and 4 MeV) is presented as a base version. The beam dynamics is calculated for two versions of the ELA. Their main parameters are given [ru

Structural damping values as a function of dynamic response stress and deformation levels

International Nuclear Information System (INIS)

Stevenson, J.D.

1980-01-01

Damping as it is normally defined is the means by which the response motion of a structural system is reduced as the result of energy losses. However, as used in the context of nuclear plant design, the effects of changes in structural stiffness, geometry, support configuration, and modulus of elasticity are also usually lumped under the general heading of damping in current design methods. For convenience in structural design, damping in usually assumed as viscous in nature and in recognition of its use in modal response spectrum dynamic analysis is normally expressed as a percent of critical. In general, it should be understood that damping as used in design or analysis of nuclear plants is an experimentally determined factor which is used to make the results of linear elasticity analysis of dynamic systems agree reasonably well with observed experimental results. In this paper, damping data existing in the open literature applicable to nuclear power plant structures and equipment is summarized and statistically analyzed. Results of this analysis are used to develop damping trend curves which predict applicable damping values to be used in design at various levels of stress or deformation. (orig.)

The influence of distributed generation penetration levels on energy markets

International Nuclear Information System (INIS)

Vahl, Fabrício Peter; Rüther, Ricardo; Casarotto Filho, Nelson

2013-01-01

Planning of national energy policies brings new dilemmas with the introduction of distributed generators (DG). Economic theory suggests that a perfectly competitive market would lead to efficient pricing. In the absence of competition, regulators play a fundamental role in attracting reasonably priced finance in order to maintain, refurbish and increase the infrastructure and provide services at a reasonable cost. Energy market price equilibrium is mainly dependent on suppliers, generators, energy sources and demand, represented by conventional utility grid users. Its behavior is similar to that of other commodities. As generation becomes less centralized with the increasing economic viability of renewable energy sources, new suppliers are being connected to the grid. Such evolution means the transition from a monopolistic market to a broader and more open environment, with an increasing number of competitors. We make use of variational inequalities to model a hypothetical DG market in different scenarios, from monopoly, to oligopoly, to open market. Such an approach enables different equilibrium outcomes due to different DG penetration levels. Based on these findings, we argue that energy policies for such markets must be developed according to each specific stage of the grid's lifecycle. We show how energy policies and market regulations may affect such a transition, which may be catastrophic if not managed properly, and which is dependent on the energy mix. -- Highlights: •DG affects energy markets depending on technologies, penetration and infrastructure. •Energy prices vary when the market moves from centralized to several suppliers. •Variational inequalities are presented to simulate a market under such transitions. •The increase of DG penetration level may present different energy prices variation. •If technical and political issues of smart grids are not improved, markets may crash

Structural Loads Analysis for Wave Energy Converters: Preprint

Energy Technology Data Exchange (ETDEWEB)

van Rij, Jennifer A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Yu, Yi-Hsiang [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Guo, Yi [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-08-09

This study explores and verifies the generalized body-modes method for evaluating the structural loads on a wave energy converter (WEC). Historically, WEC design methodologies have focused primarily on accurately evaluating hydrodynamic loads, while methodologies for evaluating structural loads have yet to be fully considered and incorporated into the WEC design process. As wave energy technologies continue to advance, however, it has become increasingly evident that an accurate evaluation of the structural loads will enable an optimized structural design, as well as the potential utilization of composites and flexible materials, and hence reduce WEC costs. Although there are many computational fluid dynamics, structural analyses and fluid-structure-interaction (FSI) codes available, the application of these codes is typically too computationally intensive to be practical in the early stages of the WEC design process. The generalized body-modes method, however, is a reduced order, linearized, frequency-domain FSI approach, performed in conjunction with the linear hydrodynamic analysis, with computation times that could realistically be incorporated into the WEC design process. The objective of this study is to verify the generalized body-modes approach in comparison to high-fidelity FSI simulations to accurately predict structural deflections and stress loads in a WEC. Two verification cases are considered, a free-floating barge and a fixed-bottom column. Details for both the generalized body-modes models and FSI models are first provided. Results for each of the models are then compared and discussed. Finally, based on the verification results obtained, future plans for incorporating the generalized body-modes method into the WEC simulation tool, WEC-Sim, and the overall WEC design process are discussed.

Energy intensity, target level of energy intensity, and room for improvement in energy intensity: An application to the study of regions in the EU

International Nuclear Information System (INIS)

Chang, Ming-Chung

2014-01-01

While the previous literature shows that a decline in energy intensity represents an improvement in energy use efficiency, it does not provide a target level of energy intensity, nor what room for improvement in terms of energy intensity could entail. This study establishes an indicator of such room for improvement in terms of energy intensity by measuring the difference between the target level of energy intensity and the actual energy intensity and thereby monitors energy use efficiency. The traditional indicator of energy intensity, defined as energy use over GDP, mainly estimates energy use efficiency, but is a partial effect between the energy input and GDP output. However, our proposed indicator of the room for improvement in terms of energy intensity is the total-factor effects based on the multiple-inputs model. By taking the 27 EU members to investigate their energy use efficiency using the indicator of the room for improvement in terms of energy intensity, this study concludes that an improvement in energy intensity does not fully depend on a decline in energy intensity, and we instead need to confirm whether the room for improvement in terms of energy intensity decreases. This finding is particularly relevant for energy policy-makers. - Highlights: • This paper establishes an indicator for the room for improvement in terms of energy intensity. • This study takes the 27 EU members to investigate their energy use efficiency. • A different result appears by using our proposed indicator