Debunching and Capture in the LEB for the SSC

Energy Technology Data Exchange (ETDEWEB)

Mahale, N.; Furman, M.

1991-05-01

The authors present the details of the capture process in the Low Energy Booster (LEB) for the SSC. They consider only the longitudinal dynamics. Space charge forces are computed quasistatically. The beam pipe is considered to be perfectly conducting. With respect to maximizing the capture efficiency and minimizing the space charge tune spread, initial few milliseconds are very important. They present only the first few milliseconds of the cycle, during which space charge effects are significant. For the numerical simulation they use the code ESME.

Energy efficiency and SINR maximization beamformers for cognitive radio utilizing sensing information

KAUST Repository

Alabbasi, Abdulrahman

2014-06-01

In this paper we consider a cognitive radio multi-input multi-output environment in which we adapt our beamformer to maximize both energy efficiency and signal to interference plus noise ratio (SINR) metrics. Our design considers an underlaying communication using adaptive beamforming schemes combined with the sensing information to achieve an optimal energy efficient system. The proposed schemes maximize the energy efficiency and SINR metrics subject to cognitive radio and quality of service constraints. Since the optimization of energy efficiency problem is not a convex problem, we transform it into a standard semi-definite programming (SDP) form to guarantee a global optimal solution. Analytical solution is provided for one scheme, while the other scheme is left in a standard SDP form. Selected numerical results are used to quantify the impact of the sensing information on the proposed schemes compared to the benchmark ones.

Energy localization in maximally entangled two- and three-qubit phase space

International Nuclear Information System (INIS)

Pashaev, Oktay K; Gurkan, Zeynep N

2012-01-01

Motivated by the Möbius transformation for symmetric points under the generalized circle in the complex plane, the system of symmetric spin coherent states corresponding to antipodal qubit states is introduced. In terms of these states, we construct the maximally entangled complete set of two-qubit coherent states, which in the limiting cases reduces to the Bell basis. A specific property of our symmetric coherent states is that they never become unentangled for any value of ψ from the complex plane. Entanglement quantifications of our states are given by the reduced density matrix and the concurrence determinant, and it is shown that our basis is maximally entangled. Universal one- and two-qubit gates in these new coherent state basis are calculated. As an application, we find the Q symbol of the XY Z model Hamiltonian operator H as an average energy function in maximally entangled two- and three-qubit phase space. It shows regular finite-energy localized structure with specific local extremum points. The concurrence and fidelity of quantum evolution with dimerization of double periodic patterns are given. (paper)

Maximizing Energy Capture of Fixed-Pitch Variable-Speed Wind Turbines

Energy Technology Data Exchange (ETDEWEB)

Pierce, K.; Migliore, P.

2000-08-01

Field tests of a variable-speed, stall-regulated wind turbine were conducted at a US Department of Energy Laboratory. A variable-speed generating system, comprising a doubly-fed generator and series-resonant power converter, was installed on a 275-kW, downwind, two-blade wind turbine. Gearbox, generator, and converter efficiency were measured in the laboratory so that rotor aerodynamic efficiency could be determined from field measurement of generator power. The turbine was operated at several discrete rotational speeds to develop power curves for use in formulating variable-speed control strategies. Test results for fixed-speed and variable-speed operation are presented along with discussion and comparison of the variable-speed control methodologies. Where possible, comparisons between fixed-speed and variable-speed operation are shown.

Low energy, low cost, efficient CO{sub 2} capture

Energy Technology Data Exchange (ETDEWEB)

Michael C. Trachtenberg; Lihong Bao; David A. Smith; Remy Dumortier [Carbozyme, Inc., Monmouth Junction, NJ (United States)

2006-07-01

This paper discusses the development and some characteristics of a new, enzyme-based, contained liquid membrane contactor to capture CO{sub 2}. The enzyme carbonic anhydrase catalyzes the removal of CO{sub 2} while the membrane contactor increases the surface area to allow the reduction of the size of the system. The modular system design is easily scaled to any required size reducing the investment costs. The system captures CO{sub 2} at a low energy and low cost promising to be a cost effective technology for CO{sub 2} capture. 5 refs., 7 figs.

Maximizing the spectral and energy efficiency of ARQ with a fixed outage probability

KAUST Repository

Hadjtaieb, Amir

2015-10-05

This paper studies the spectral and energy efficiency of automatic repeat request (ARQ) in Nakagami-m block-fading channels. The source encodes each packet into L similar sequences and transmits them to the destination in the L subsequent time slots. The destination combines the L sequences using maximal ratio combining and tries to decode the information. In case of decoding failure, the destination feeds back a negative acknowledgment and then the source sends the same L sequences to the destination. This process continues until successful decoding occurs at the destination with no limit on the number of retransmissions. We consider two optimization problems. In the first problem, we maximize the spectral efficiency of the system with respect to the rate for a fixed power. In the second problem, we maximize the energy efficiency with respect to the transmitted power for a fixed rate. © 2015 IEEE.

Adaptive control algorithm for improving power capture of wind turbines in turbulent winds

DEFF Research Database (Denmark)

Diaz-Guerra, Lluis; Adegas, Fabiano Daher; Stoustrup, Jakob

2012-01-01

, the complex and time-varying aerodynamics a WT face due to turbulent winds make their determination a hard task. The selected constant parameters may maximize energy for a particular, but not all, wind regime conditions. Adaptivity can modify the controller to increase power capture under variable wind...

Maritime energy and security: Synergistic maximization or necessary tradeoffs?

International Nuclear Information System (INIS)

Nyman, Elizabeth

2017-01-01

Offshore energy is big business. The traditional source of maritime energy, offshore petroleum and gas, has been on the rise since a reliable method of extraction was discovered in the mid-20th century. Lately, it has been joined by offshore wind and tidal power as alternative “green” sources of maritime energy. Yet all of this has implications for maritime environmental regimes as well, as maritime energy extraction/generation can have a negative effect on the ocean environment. This paper considers two major questions surrounding maritime energy and environmental concerns. First, how and why do these two concerns, maritime energy and environmental protection, play against each other? Second, how can states both secure their energy and environmental securities in the maritime domain? Maximizing maritime energy output necessitates some environmental costs and vice versa, but these costs vary with the type of offshore energy technology used and with the extent to which states are willing to expend effort to protect both environmental and energy security. - Highlights: • Security is a complicated concept with several facets including energy and environmental issues. • Offshore energy contributes to energy supply but can have environmental and monitoring costs. • Understanding the contribution of offshore energy to security depends on which security facet is deemed most important.

On Maximizing the Throughput of Packet Transmission under Energy Constraints.

Science.gov (United States)

Wu, Weiwei; Dai, Guangli; Li, Yan; Shan, Feng

2018-06-23

More and more Internet of Things (IoT) wireless devices have been providing ubiquitous services over the recent years. Since most of these devices are powered by batteries, a fundamental trade-off to be addressed is the depleted energy and the achieved data throughput in wireless data transmission. By exploiting the rate-adaptive capacities of wireless devices, most existing works on energy-efficient data transmission try to design rate-adaptive transmission policies to maximize the amount of transmitted data bits under the energy constraints of devices. Such solutions, however, cannot apply to scenarios where data packets have respective deadlines and only integrally transmitted data packets contribute. Thus, this paper introduces a notion of weighted throughput, which measures how much total value of data packets are successfully and integrally transmitted before their own deadlines. By designing efficient rate-adaptive transmission policies, this paper aims to make the best use of the energy and maximize the weighted throughput. What is more challenging but with practical significance, we consider the fading effect of wireless channels in both offline and online scenarios. In the offline scenario, we develop an optimal algorithm that computes the optimal solution in pseudo-polynomial time, which is the best possible solution as the problem undertaken is NP-hard. In the online scenario, we propose an efficient heuristic algorithm based on optimal properties derived for the optimal offline solution. Simulation results validate the efficiency of the proposed algorithm.

Direct capture of low-energy neutrons by {sup 16}O

Energy Technology Data Exchange (ETDEWEB)

Kitazawa, Hideo [Tokyo Inst. of Tech., Nagatsuta, Yokohama (Japan). Interdisciplinary Graduate School of Science; Igashira, Masayuki

1998-03-01

A dispersive optical potential for the interaction between low-energy neutrons and {sup 16}O-nuclei is derived from a dispersion relation based on the Feshbach generalized optical model. This potential is applied to direct-capture model calculations in explaining the observed off-resonance capture transitions to the ground (5/2{sup +}) and 871 keV(1/2{sup +}) levels in {sup 17}O at neutron energies of 20-70 keV. The model calculations take account of the spatial nonlocality of the neutron-nucleus interaction potential. (author)

Energy and material balance of CO2 capture from ambient air.

Science.gov (United States)

Zeman, Frank

2007-11-01

Current Carbon Capture and Storage (CCS) technologies focus on large, stationary sources that produce approximately 50% of global CO2 emissions. We propose an industrial technology that captures CO2 directly from ambient air to target the remaining emissions. First, a wet scrubbing technique absorbs CO2 into a sodium hydroxide solution. The resultant carbonate is transferred from sodium ions to calcium ions via causticization. The captured CO2 is released from the calcium carbonate through thermal calcination in a modified kiln. The energy consumption is calculated as 350 kJ/mol of CO2 captured. It is dominated by the thermal energy demand of the kiln and the mechanical power required for air movement. The low concentration of CO2 in air requires a throughput of 3 million cubic meters of air per ton of CO2 removed, which could result in significant water losses. Electricity consumption in the process results in CO2 emissions and the use of coal power would significantly reduce to net amount captured. The thermodynamic efficiency of this process is low but comparable to other "end of pipe" capture technologies. As another carbon mitigation technology, air capture could allow for the continued use of liquid hydrocarbon fuels in the transportation sector.

Energy Efficiency and SINR Maximization Beamformers for Spectrum Sharing With Sensing Information

KAUST Repository

Alabbasi, AbdulRahman; Rezki, Zouheir; Shihada, Basem

2014-01-01

an underlaying communication using adaptive beamforming schemes combined with sensing information to achieve optimal energy-efficient systems. The proposed schemes maximize EE and SINR metrics subject to cognitive radio and quality-of-service constraints

Capture of muons with high energy transfer (μ-,pn) on the 2040Ca

International Nuclear Information System (INIS)

Arques, Marc

1978-01-01

As several Russian experiments had shown that the capture of mesons of negative charge in some target nuclei (Si, S, Ca, Cu, Pb) could lead to the emission of high energy protons and neutrons (a kinetic energy higher than 30 MeV), the author reports a preliminary measurement of the capture or a negatively charged muon in a K orbit around a nucleus, actually a capture with a simultaneous emission of a proton and a neutron, and of a neutrino with an as low as possible energy. After having outlined the interest of such an experiment, the author describes the kinematics of capture of a resting muon, the production of muons, the experimental assembly, the experiment and the associated electronics. Results are interpreted

Low-energy restoration of parity and maximal symmetry

International Nuclear Information System (INIS)

Raychaudhuri, A.; Sarkar, U.

1982-01-01

The maximal symmetry of fermions of one generation, SU(16), which includes the left-right-symmetric Pati-Salam group, SU(4)/sub c/ x SU(2) /sub L/ x SU(2)/sub R/, as a subgroup, allows the possibility of a low-energy (M/sub R/approx.100 GeV) breaking of the left-right symmetry. It is known that such a low-energy restoration of parity can be consistent with weak-interaction phenomenology. We examine different chains of descent of SU(16) that admit a low value of M/sub R/ and determine the other intermediate symmetry-breaking mass scales associated with each of these chains. These additional mass scales provide an alternative to the ''great desert'' expected in some grand unifying models. The contributions of the Higgs fields in the renormalization-group equations are retained and are found to be important

Density Functional Theory Calculations of Activation Energies for Carrier Capture by Defects in Semiconductors

Science.gov (United States)

Modine, N. A.; Wright, A. F.; Lee, S. R.

The rate of defect-induced carrier recombination is determined by both defect levels and carrier capture cross-sections. Density functional theory (DFT) has been widely and successfully used to predict defect levels, but only recently has work begun to focus on using DFT to determine carrier capture cross-sections. Lang and Henry developed the theory of carrier-capture by multiphonon emission in the 1970s and showed that carrier-capture cross-sections differ between defects primarily due to differences in their carrier capture activation energies. We present an approach to using DFT to calculate carrier capture activation energies that does not depend on an assumed configuration coordinate and that fully accounts for anharmonic effects, which can substantially modify carrier activation energies. We demonstrate our approach for intrinisic defects in GaAs and GaN and discuss how our results depend on the choice of exchange-correlation functional and the treatment of spin polarization. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

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.

Energy Efficiency Maximization for WSNs with Simultaneous Wireless Information and Power Transfer.

Science.gov (United States)

Yu, Hongyan; Zhang, Yongqiang; Guo, Songtao; Yang, Yuanyuan; Ji, Luyue

2017-08-18

Recently, the simultaneous wireless information and power transfer (SWIPT) technique has been regarded as a promising approach to enhance performance of wireless sensor networks with limited energy supply. However, from a green communication perspective, energy efficiency optimization for SWIPT system design has not been investigated in Wireless Rechargeable Sensor Networks (WRSNs). In this paper, we consider the tradeoffs between energy efficiency and three factors including spectral efficiency, the transmit power and outage target rate for two different modes, i.e., power splitting (PS) and time switching modes (TS), at the receiver. Moreover, we formulate the energy efficiency maximization problem subject to the constraints of minimum Quality of Service (QoS), minimum harvested energy and maximum transmission power as non-convex optimization problem. In particular, we focus on optimizing power control and power allocation policy in PS and TS modes to maximize energy efficiency of data transmission. For PS and TS modes, we propose the corresponding algorithm to characterize a non-convex optimization problem that takes into account the circuit power consumption and the harvested energy. By exploiting nonlinear fractional programming and Lagrangian dual decomposition, we propose suboptimal iterative algorithms to obtain the solutions of non-convex optimization problems. Furthermore, we derive the outage probability and effective throughput from the scenarios that the transmitter does not or partially know the channel state information (CSI) of the receiver. Simulation results illustrate that the proposed optimal iterative algorithm can achieve optimal solutions within a small number of iterations and various tradeoffs between energy efficiency and spectral efficiency, transmit power and outage target rate, respectively.

Energy Efficiency Maximization for WSNs with Simultaneous Wireless Information and Power Transfer

Science.gov (United States)

Yu, Hongyan; Zhang, Yongqiang; Yang, Yuanyuan; Ji, Luyue

2017-01-01

Recently, the simultaneous wireless information and power transfer (SWIPT) technique has been regarded as a promising approach to enhance performance of wireless sensor networks with limited energy supply. However, from a green communication perspective, energy efficiency optimization for SWIPT system design has not been investigated in Wireless Rechargeable Sensor Networks (WRSNs). In this paper, we consider the tradeoffs between energy efficiency and three factors including spectral efficiency, the transmit power and outage target rate for two different modes, i.e., power splitting (PS) and time switching modes (TS), at the receiver. Moreover, we formulate the energy efficiency maximization problem subject to the constraints of minimum Quality of Service (QoS), minimum harvested energy and maximum transmission power as non-convex optimization problem. In particular, we focus on optimizing power control and power allocation policy in PS and TS modes to maximize energy efficiency of data transmission. For PS and TS modes, we propose the corresponding algorithm to characterize a non-convex optimization problem that takes into account the circuit power consumption and the harvested energy. By exploiting nonlinear fractional programming and Lagrangian dual decomposition, we propose suboptimal iterative algorithms to obtain the solutions of non-convex optimization problems. Furthermore, we derive the outage probability and effective throughput from the scenarios that the transmitter does not or partially know the channel state information (CSI) of the receiver. Simulation results illustrate that the proposed optimal iterative algorithm can achieve optimal solutions within a small number of iterations and various tradeoffs between energy efficiency and spectral efficiency, transmit power and outage target rate, respectively. PMID:28820496

The Ca-looping process for CO2 capture and energy storage: role of nanoparticle technology

Science.gov (United States)

Valverde, Jose Manuel

2018-02-01

The calcium looping (CaL) process, based on the cyclic carbonation/calcination of CaO, has come into scene in the last years with a high potential to be used in large-scale technologies aimed at mitigating global warming. In the CaL process for CO2 capture, the CO2-loaded flue gas is used to fluidize a bed of CaO particles at temperatures around 650 °C. The carbonated particles are then circulated into a calciner reactor wherein the CaO solids are regenerated at temperatures near 950 °C under high CO2 concentration. Calcination at such harsh conditions causes a marked sintering and loss of reactivity of the regenerated CaO. This main drawback could be however compensated from the very low cost of natural CaO precursors such as limestone or dolomite. Another emerging application of the CaL process is thermochemical energy storage (TCES) in concentrated solar power (CSP) plants. Importantly, carbonation/calcination conditions to maximize the global CaL-CSP plant efficiency could differ radically from those used for CO2 capture. Thus, carbonation could be carried out at high temperatures under high CO2 partial pressure for maximum efficiency, whereas the solids could be calcined at relatively low temperatures in the absence of CO2 to promote calcination. Our work highlights the critical role of carbonation/calcination conditions on the performance of CaO derived from natural precursors. While conditions in the CaL process for CO2 capture lead to a severe CaO deactivation with the number of cycles, the same material may exhibit a high and stable conversion at optimum CaL-CSP conditions. Moreover, the type of CaL conditions influences critically the reaction kinetics, which plays a main role on the optimization of relevant operation parameters such as the residence time in the reactors. This paper is devoted to a brief review on the latest research activity in our group concerning these issues as well as the possible role of nanoparticle technology to enhance the

Can we capture energy in space?

International Nuclear Information System (INIS)

Anon.

2009-01-01

The vagaries of the weather here on earth and the nightly blackout limit the power we can get from solar energy. But this energy could take on a whole new dimension if it can be captured in space 24 hours a day by gigantic stations and transmitted to earth. It is not a new idea. The concept involves transmitting several gigawatts of energy from space to earth via microwaves using geosynchronous satellites equipped with solar collectors. The concept keeps resurfacing every ten years or so, triggering assessments by various businesses and institutions, mostly American, such as the US Department of Energy, NASA, Raytheon, Lockheed Martin and Boeing. Despite all the resources available, the various technical solutions considered have never sparked joint programs, for lack of a real commitment to cooperation. Today, the required funding will likely have to come from international cooperation. A number of private companies have recently been created to begin the process of raising funds and pooling the necessary capabilities. The goal is to develop mature, economically viable technologies for commercial deployment in around 2030

Energy Capture from Thermolytic Solutions in Microbial Reverse-Electrodialysis Cells

KAUST Repository

Cusick, R. D.

2012-03-01

Reverse electrodialysis allows for the capture of energy from salinity gradients between salt and fresh waters, but potential applications are currently limited to coastal areas and the need for a large number of membrane pairs. Using salt solutions that could be continuously regenerated with waste heat (≥40°C) and conventional technologies would allow much wider applications of salinity-gradient power production. We used reverse electrodialysis ion-exchange membrane stacks in microbial reverse- electrodialysis cells to efficiently capture salinity-gradient energy from ammonium bicarbonate salt solutions. The maximum power density using acetate reached 5.6 watts per square meter of cathode surface area, which was five times that produced without the dialysis stack, and 3.0 ± 0.05 watts per square meter with domestic wastewater. Maximum energy recovery with acetate reached 30 ± 0.5%.

Solar photovoltaic system design optimization by shading analysis to maximize energy generation from limited urban area

International Nuclear Information System (INIS)

Rachchh, Ravi; Kumar, Manoj; Tripathi, Brijesh

2016-01-01

Highlights: • Scheme to maximize total number of solar panels in a given area. • Enhanced energy output from a fixed area without compromising the efficiency. • Capacity and generated energy are enhanced by more than 25%. - Abstract: In the urban areas the demand of solar power is increasing due to better awareness about the emission of green house gases from conventional thermal power plants and significant decrease in the installation cost of residential solar power plants. But the land cost and the under utilization of available space is hindering its further growth. Under these circumstances, solar photovoltaic system installation needs to accommodate the maximum number of solar panels in either roof-top or land-mounted category. In this article a new approach is suggested to maximize the total number of solar panels in a given area with enhanced energy output without compromising the overall efficiency of the system. The number of solar panels can be maximized in a solar photovoltaic energy generation system by optimizing installation parameters such as tilt angle, pitch, gain factor, altitude angle and shading to improve the energy yield. In this paper mathematical analysis is done to show that the capacity and generated energy can be enhanced by more than 25% for a given land area by optimization various parameters.

Radiative capture of nucleons at astrophysical energies with single-particle states

International Nuclear Information System (INIS)

Huang, J.T.; Bertulani, C.A.; Guimaraes, V.

2010-01-01

Radiative capture of nucleons at energies of astrophysical interest is one of the most important processes for nucleosynthesis. The nucleon capture can occur either by a compound nucleus reaction or by a direct process. The compound reaction cross sections are usually very small, especially for light nuclei. The direct capture proceeds either via the formation of a single-particle resonance or a non-resonant capture process. In this work we calculate radiative capture cross sections and astrophysical S-factors for nuclei in the mass region A<20 using single-particle states. We carefully discuss the parameter fitting procedure adopted in the simplified two-body treatment of the capture process. Then we produce a detailed list of cases for which the model works well. Useful quantities, such as spectroscopic factors and asymptotic normalization coefficients, are obtained and compared to published data.

S-factor for radiative capture reactions for light nuclei at astrophysical energies

Science.gov (United States)

Ghasemi, Reza; Sadeghi, Hossein

2018-06-01

The astrophysical S-factors of thermonuclear reactions, including radiative capture reactions and their analysis in the frame of different theoretical models, are the main source of nuclear processes. We have done research on the radiative capture reactions importance in the framework of a potential model. Investigation of the reactions in the astrophysical energies is of great interest in the aspect of astrophysics and nuclear physics for developing correct models of burning and evolution of stars. The experimental measurements are very difficult and impossible because of these reactions occurrence at low-energies. In this paper we do a calculation on radiative capture astrophysical S-factors for nuclei in the mass region A theoretical methods.

Maximizing noise energy for noise-masking studies.

Science.gov (United States)

Jules Étienne, Cédric; Arleo, Angelo; Allard, Rémy

2017-08-01

Noise-masking experiments are widely used to investigate visual functions. To be useful, noise generally needs to be strong enough to noticeably impair performance, but under some conditions, noise does not impair performance even when its contrast approaches the maximal displayable limit of 100 %. To extend the usefulness of noise-masking paradigms over a wider range of conditions, the present study developed a noise with great masking strength. There are two typical ways of increasing masking strength without exceeding the limited contrast range: use binary noise instead of Gaussian noise or filter out frequencies that are not relevant to the task (i.e., which can be removed without affecting performance). The present study combined these two approaches to further increase masking strength. We show that binarizing the noise after the filtering process substantially increases the energy at frequencies within the pass-band of the filter given equated total contrast ranges. A validation experiment showed that similar performances were obtained using binarized-filtered noise and filtered noise (given equated noise energy at the frequencies within the pass-band) suggesting that the binarization operation, which substantially reduced the contrast range, had no significant impact on performance. We conclude that binarized-filtered noise (and more generally, truncated-filtered noise) can substantially increase the energy of the noise at frequencies within the pass-band. Thus, given a limited contrast range, binarized-filtered noise can display higher energy levels than Gaussian noise and thereby widen the range of conditions over which noise-masking paradigms can be useful.

Energy Efficiency and SINR Maximization Beamformers for Spectrum Sharing With Sensing Information

KAUST Repository

Alabbasi, Abdulrahman

2014-09-01

In this paper, we consider a cognitive radio multi-input-multi-output environment, in which we adapt our beamformer to maximize both energy efficiency (EE) and signal-to-interference-plus-noise ratio (SINR) metrics. Our design considers an underlaying communication using adaptive beamforming schemes combined with sensing information to achieve optimal energy-efficient systems. The proposed schemes maximize EE and SINR metrics subject to cognitive radio and quality-of-service constraints. The analysis of the proposed schemes is classified into two categories based on knowledge of the secondary-transmitter-to-primary-receiver channel. Since the optimizations of EE and SINR problems are not convex problems, we transform them into a standard semidefinite programming (SDP) form to guarantee that the optimal solutions are global. An analytical solution is provided for one scheme, while the second scheme is left in a standard SDP form. Selected numerical results are used to quantify the impact of the sensing information on the proposed schemes compared to the benchmark ones.

Multinucleon effects in muon capture on 3He at high energy transfer

International Nuclear Information System (INIS)

Kuhn, S.E.; Cummings, W.J.; Dodge, G.E.; Hanna, S.S.; King, B.H.; Shin, Y.M.; Congleton, J.G.; Helmer, R.; Schubank, R.B.; Stevenson, N.R.; Wienands, U.; Lee, Y.K.; Mason, G.R.; King, B.E.; Chung, K.S.; Lee, J.M.; Rosenzweig, D.P.

1994-01-01

Energy spectra of both protons and deuterons emitted following the capture of negative muons by 3 He nuclei have been measured for energies above 15 MeV. A limited number of proton-neutron pairs emitted in coincidence were also observed. A simple plane wave impulse approximation (PWIA) model calculation yields fair agreement with the measured proton energy spectra, but underpredicts the measured rate of deuteron production above our energy threshold by a large factor. A more sophisticated PWIA calculation for the two-body breakup channel, based on a realistic three-body wave function for the initial state, is closer to the deuteron data at moderate energies, but still is significantly lower near the kinematic end point. The proton-neutron coincidence data also point to the presence of significant strength involving more than one nucleon in the capture process at high energy transfer. These results indicate that additional terms in the capture matrix element beyond the impulse approximation contribution may be required to explain the experimental data. Specifically, the inclusion of nucleon-nucleon correlations in the initial or final state and meson exchange current contributions could bring calculations into better agreement with our data. A fully microscopic calculation would thus open the possibility for a quantitative test of multinucleon effects in the weak interaction

Maximization of energy in the output of a linear system

International Nuclear Information System (INIS)

Dudley, D.G.

1976-01-01

A time-limited signal which, when passed through a linear system, maximizes the total output energy is considered. Previous work has shown that the solution is given by the eigenfunction associated with the maximum eigenvalue in a Hilbert-Schmidt integral equation. Analytical results are available for the case where the transfer function is a low-pass filter. This work is extended by obtaining a numerical solution to the integral equation which allows results for reasonably general transfer functions

Exchange currents in low-energy nucleon capture by 3He

International Nuclear Information System (INIS)

Wervelman, Rob.

1991-01-01

The studies described in this thesis concern absolute cross-section measurements of the radiative neutron capture reactions 3 He (n,γ) 4 He and 3 He(n,γγ) 4 He, and are complements with shell-model calculations on the radiative thermal neutron capture reaction by 3 He and on the weak 3 He(p,e + ν e ) 4 He reaction. The experiments have been performed at two neutron energies, with sub-thermal neutrons where s-wave capture is dominant, and with a quasi-monochromatic 24.5 keV neutron beam (p-wave capture). It has been found that the thermal neutron capture cross section of 3 He is 55±3 μb. Measured at 24.5 keV-neutron energy, the radiative capture cross section for p-wave neutrons turned out to be 9.1±0.8 μb. A measurement on the double-photon reaction 3 He(n th ,γγ) has yielded a cross-section value of 30±80 μb. In the theoretical part of the work a standard model of nuclear weak and electromagnetic interaction currents, consisting of a one-body impulse approximation and a two-body meson-exchange current part, has been applied to the process of nucleon capture by 3 He. Within the framework of a (0+2) (h/2π)ω shell-model calculation, using Sussex matrix elements for the 3 He and 4 He ground state wave functions, the empirical radiative cross sections for thermal neutrons of 3 He could be reproduced with satisfactory agreement. The total MEC correction to the radiative thermal neutron capture cross section is rather small because large cancellations occur between the various contributions. In the 3 He(p,e + ν e ) 4 He reaction meson-exchange contributions enlarge the astrophysical S-factor by more than a factor two. The matrix element ratio of the weak 3 He+p and the electromagnetic 3 He+n reaction is calculated to be (4.3±0.6)g A C 0 . This ratio has been found to be fairly insensitive to the percentage D-state admixtures in the 3 He and 4 He ground state wave functions. (author). 129 refs.; 24 figs.; 5 tabs

Strange Meson Radiative Capture on the Proton in Low Energy QCD Lagrangian

Institute of Scientific and Technical Information of China (English)

ZHOULi－Juan; MAWei－Xing; 等

2002-01-01

Based on our low energy QCD Lagrangian description of strange meson photoproduction off the proton and the crossing symmetry,the strange meson radiative capture on the proton,K-+p→γ+A,is investigated in the [SU SF(6)×O(3)]sym,SUc(3) quark model of baryon structure with the same input parameter,the only strong coupling constant αM,as that in the strange meson photoproduction off the proton γ+p-→K+ Α，a crossing channel of the capture reaction,A good agreement on the branching ratio between the predictions and data is obtained successfully.This excellent fit indicates that our low energy QCD Lagrangian theory with only one free parameter is an advanced and unified description of strange meson photoproduction and its associated radiative capture.

Power maximization of a point absorber wave energy converter using improved model predictive control

Science.gov (United States)

Milani, Farideh; Moghaddam, Reihaneh Kardehi

2017-08-01

This paper considers controlling and maximizing the absorbed power of wave energy converters for irregular waves. With respect to physical constraints of the system, a model predictive control is applied. Irregular waves' behavior is predicted by Kalman filter method. Owing to the great influence of controller parameters on the absorbed power, these parameters are optimized by imperialist competitive algorithm. The results illustrate the method's efficiency in maximizing the extracted power in the presence of unknown excitation force which should be predicted by Kalman filter.

Maximizing hosting capacity of renewable energy sources in distribution networks: A multi-objective and scenario-based approach

International Nuclear Information System (INIS)

Rabiee, Abbas; Mohseni-Bonab, Seyed Masoud

2017-01-01

Due to the development of renewable energy sources (RESs), maximization of hosting capacity (HC) of RESs has gained significant interest in the existing and future power systems. HC maximization should be performed considering various technical constraints like power flow equations, limits on the distribution feeders' voltages and currents, as well as economic constraints such as the cost of energy procurement from the upstream network and power generation by RESs. RESs are volatile and uncertain in nature. Thus, it is necessary to handle their inherent uncertainties in the HC maximization problem. Wind power is now the fastest growing RESs around the world. Hence, in this paper a stochastic multi-objective optimization model is proposed to maximize the distribution network's HC for wind power and minimize the energy procurement costs in a wind integrated power system. The following objective functions are considered: 1) Cost of the purchased energy from upstream network (to be minimized) and 2) Operation and maintenance cost of wind farms. The proposed model is examined on a standard radial 69 bus distribution feeder and a practical 152 bus distribution system. The numerical results substantiate that the proposed model is an effective tool for distribution network operators (DNOs) to consider both technical and economic aspects of distribution network's HC for RESs. - Highlights: • Hosting capacity of wind power is improved in distribution feeders. • A stochastic multi-objective optimization model is proposed. • Wind power and load uncertainties are modeled by scenario based approach. • Purchased energy cost from upstream network and O&M cost of wind farms are used.

Maximization of Energy Efficiency in Wireless ad hoc and Sensor Networks With SERENA

Directory of Open Access Journals (Sweden)

Saoucene Mahfoudh

2009-01-01

Full Text Available In wireless ad hoc and sensor networks, an analysis of the node energy consumption distribution shows that the largest part is due to the time spent in the idle state. This result is at the origin of SERENA, an algorithm to SchEdule RoutEr Nodes Activity. SERENA allows router nodes to sleep, while ensuring end-to-end communication in the wireless network. It is a localized and decentralized algorithm assigning time slots to nodes. Any node stays awake only during its slot and the slots assigned to its neighbors, it sleeps the remaining time. Simulation results show that SERENA enables us to maximize network lifetime while increasing the number of user messages delivered. SERENA is based on a two-hop coloring algorithm, whose complexity in terms of colors and rounds is evaluated. We then quantify the slot reuse. Finally, we show how SERENA improves the node energy consumption distribution and maximizes the energy efficiency of wireless ad hoc and sensor networks. We compare SERENA with classical TDMA and optimized variants such as USAP in wireless ad hoc and sensor networks.

Calculations on Electron Capture in Low Energy Ion-Molecule Collisions

Energy Technology Data Exchange (ETDEWEB)

Stancil, P.C. [Oak Ridge National Lab., TN (United States); Zygelman, B. [W.M. Keck Lab. for Computational Physics, Univ. of Nevada, Las Vegas, NV (United States); Kirby, K. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

1997-12-31

Recent progress on the application of a quantal, molecular-orbital, close-coupling approach to the calculation of electron capture in collisions of multiply charged ions with molecules is discussed. Preliminary results for single electron capture by N{sup 2+} with H{sub 2} are presented. Electron capture by multiply charged ions colliding with H{sub 2} is an important process in laboratory and astrophysical plasmas. It provides a recombination mechanism for multiply charged ions in x-ray ionized astronomical environments which may have sparse electron and atomic hydrogen abundances. In the divertor region of a tokamak fusion device, charge exchange of impurity ions with H{sub 2} plays a role in the ionization balance and the production of radiative energy loss leading to cooling, X-ray and ultraviolet auroral emission from Jupiter is believed to be due to charge exchange of O and S ions with H{sub 2} in the Jovian atmosphere. Solar wind ions interacting with cometary molecules may have produced the x-rays observed from Comet Hyakutake. In order to model and understand the behavior of these environments, it is necessary to obtain total, electronic state-selective (ESS), and vibrational (or rotational) state-selective (VSS) capture cross sections for collision energies as low as 10 meV/amu to as high as 100 keV/amu in some instances. Fortunately, charge transfer with molecular targets has received considerable experimental attention. Numerous measurements have been made with flow tubes, ion traps, and ion beams. Flow tube and ion trap studies generally provide information on rate coefficients for temperatures between 800 K and 20,000 K. In this article, we report on the progress of our group in implementing a quantum-mechanical Molecular Orbital Close Coupling (MOCC) approach to the study of electron capture by multiply charged ions in collisions with molecules. We illustrate this with a preliminary investigation of Single Electron Capture (SEC) by N{sup 2+} with H

Mutual capture of dipolar molecules at low and very low energies. I. Approximate analytical treatment.

Science.gov (United States)

Nikitin, E E; Troe, J

2010-09-16

Approximate analytical expressions are derived for the low-energy rate coefficients of capture of two identical dipolar polarizable rigid rotors in their lowest nonresonant (j(1) = 0 and j(2) = 0) and resonant (j(1) = 0,1 and j(2) = 1,0) states. The considered range extends from the quantum, ultralow energy regime, characterized by s-wave capture, to the classical regime described within fly wheel and adiabatic channel approaches, respectively. This is illustrated by the table of contents graphic (available on the Web) that shows the scaled rate coefficients for the mutual capture of rotors in the resonant state versus the reduced wave vector between the Bethe zero-energy (left arrows) and classical high-energy (right arrow) limits for different ratios δ of the dipole-dipole to dispersion interaction.

Low-energy near Earth asteroid capture using Earth flybys and aerobraking

Science.gov (United States)

Tan, Minghu; McInnes, Colin; Ceriotti, Matteo

2018-04-01

Since the Sun-Earth libration points L1 and L2 are regarded as ideal locations for space science missions and candidate gateways for future crewed interplanetary missions, capturing near-Earth asteroids (NEAs) around the Sun-Earth L1/L2 points has generated significant interest. Therefore, this paper proposes the concept of coupling together a flyby of the Earth and then capturing small NEAs onto Sun-Earth L1/L2 periodic orbits. In this capture strategy, the Sun-Earth circular restricted three-body problem (CRTBP) is used to calculate target Lypaunov orbits and their invariant manifolds. A periapsis map is then employed to determine the required perigee of the Earth flyby. Moreover, depending on the perigee distance of the flyby, Earth flybys with and without aerobraking are investigated to design a transfer trajectory capturing a small NEA from its initial orbit to the stable manifolds associated with Sun-Earth L1/L2 periodic orbits. Finally, a global optimization is carried out, based on a detailed design procedure for NEA capture using an Earth flyby. Results show that the NEA capture strategies using an Earth flyby with and without aerobraking both have the potential to be of lower cost in terms of energy requirements than a direct NEA capture strategy without the Earth flyby. Moreover, NEA capture with an Earth flyby also has the potential for a shorter flight time compared to the NEA capture strategy without the Earth flyby.

Integrating geothermal into coal-fired power plant with carbon capture: A comparative study with solar energy

International Nuclear Information System (INIS)

Wang, Fu; Deng, Shuai; Zhao, Jun; Zhao, Jiapei; Yang, Guohua; Yan, Jinyue

2017-01-01

Highlights: • Post-combustion carbon capture integrating geothermal energy was proposed. • A 300 MWe subcritical coal-fired plant was selected as the baseline. • The geothermal assisted carbon capture system was compared with solar assisted carbon capture plant. • Two different locations were chosen for the technical and economical comparison. • Using medium temperature geothermal thermal energy to replace steam extraction performs better performance. - Abstract: A new system integrating geothermal energy into post-combustion carbon capture is proposed in this paper. Geothermal energy at medium temperatures is used to provide the required thermal heat for solvent regeneration. The performance of this system is compared with solar assisted carbon capture plant via technical and economic evaluation. A 300 MWe coal-fired power plant is selected as the reference case, and two different locations based on the local climatic conditions and geothermal resources are chosen for the comparison. The results show that the geothermal assisted post-combustion carbon capture plant has better performances than the solar assisted one in term of the net power output and annual electricity generation. The net plant average efficiency based on lower heating value can be increased by 2.75% with a thermal load fraction of about 41%. Results of economic assessment show that the proposed geothermal assisted post-combustion carbon capture system has lower levelized costs of electricity and cost of carbon dioxide avoidance compared to the solar assisted post-combustion carbon capture plant. In order to achieve comparative advantages over the reference post-combustion carbon capture plant in both locations, the price of solar collector has to be lower than 70 USD/m 2 , and the drilling depth of the geothermal well shall be less than 2.1 km.

Electron capture by multicharged ions at eV energies

International Nuclear Information System (INIS)

Havener, C.C.; Huq, M.S.; Meyer, F.W.; Phaneuf, R.A.

1988-01-01

A multicharged ion-atom merged-beams apparatus has been used in conjunction with the ORNL-ECR ion source to measure accurate absolute electron-capture cross sections in the energy range from below 1 eV/amu to 1500 eV/amu. Measurements for N/sup 3+,4+,5+/ /plus/ H(D) collisions indicate good agreement with available theoretical calculations. However, measurements with O 5+ /plus/ H(D) show an unexpected low-energy behavior which may be attributable to the ion-induced-dipole attraction between the reactants. Scaled Landau-Zener calculations presented here identify a transfer plus excitation channel which has the correct energy dependence at low energies. This finding suggest the need for a comprehensive coupled channel calculation which would include such product states. 25 refs., 8 figs

Optimising the Target and Capture Sections of the Neutrino Factory

CERN Document Server

Hansen, Ole Martin; Stapnes, Steinar

The Neutrino Factory is designed to produce an intense high energy neutrino beam from stored muons. The majority of the muons are obtained from the decay of pions, produced by a proton beam impinging on a free-flowing mercury-jet target and captured by a high magnetic field. It is important to capture a large fraction of the produced pions to maximize the intensity of the neutrino beam. Various optimisation studies have been performed with the aim of maximising the muon influx to the accelerator and thus the neutrino beam intensity. The optimisation studies were performed with the use of Monte Carlo simulation tools. The production of secondary particles, by interactions between the incoming proton beam and the mercury target, was optimised by varying the proton beam impact position and impact angles on the target. The proton beam and target interaction region was studied and showed to be off the central axis of the capture section in the baseline configuration. The off-centred interaction region resulted in ...

Optimal size of stochastic Hodgkin-Huxley neuronal systems for maximal energy efficiency in coding pulse signals

Science.gov (United States)

Yu, Lianchun; Liu, Liwei

2014-03-01

The generation and conduction of action potentials (APs) represents a fundamental means of communication in the nervous system and is a metabolically expensive process. In this paper, we investigate the energy efficiency of neural systems in transferring pulse signals with APs. By analytically solving a bistable neuron model that mimics the AP generation with a particle crossing the barrier of a double well, we find the optimal number of ion channels that maximizes the energy efficiency of a neuron. We also investigate the energy efficiency of a neuron population in which the input pulse signals are represented with synchronized spikes and read out with a downstream coincidence detector neuron. We find an optimal number of neurons in neuron population, as well as the number of ion channels in each neuron that maximizes the energy efficiency. The energy efficiency also depends on the characters of the input signals, e.g., the pulse strength and the interpulse intervals. These results are confirmed by computer simulation of the stochastic Hodgkin-Huxley model with a detailed description of the ion channel random gating. We argue that the tradeoff between signal transmission reliability and energy cost may influence the size of the neural systems when energy use is constrained.

The adenylate energy charge as a new and useful indicator of capture stress in chondrichthyans.

Science.gov (United States)

Guida, Leonardo; Walker, Terence I; Reina, Richard D

2016-02-01

Quantifying the physiological stress response of chondrichthyans to capture has assisted the development of fishing practices conducive to their survival. However, currently used indicators of stress show significant interspecific and intraspecific variation in species' physiological responses and tolerances to capture. To improve our understanding of chondrichthyan stress physiology and potentially reduce variation when quantifying the stress response, we investigated the use of the adenylate energy charge (AEC); a measure of available metabolic energy. To determine tissues sensitive to metabolic stress, we extracted samples of the brain, heart, liver, white muscle and blood from gummy sharks (Mustelus antarcticus) immediately following gillnet capture and after 3 h recovery under laboratory conditions. Capture caused significant declines in liver, white muscle and blood AEC, whereas no decline was detected in the heart and brain AEC. Following 3 h of recovery from capture, the AEC of the liver and blood returned to "unstressed" levels (control values) whereas white muscle AEC was not significantly different to that immediately after capture. Our results show that the liver is most sensitive to metabolic stress and white muscle offers a practical method to sample animals non-lethally for determination of the AEC. The AEC is a highly informative indicator of stress and unlike current indicators, it can directly measure the change in available energy and thus the metabolic stress experienced by a given tissue. Cellular metabolism is highly conserved across organisms and, therefore, we think the AEC can also provide a standardised form of measuring capture stress in many chondrichthyan species.

Maximizing the energy storage performance of phase change thermal storage systems

Energy Technology Data Exchange (ETDEWEB)

Amin, N.A.M.; Bruno, F.; Belusko, M. [South Australia Univ., Mawson Lakes, South Australia (Australia). Inst. for Sustainable Systems and Technologies

2009-07-01

The demand for electricity in South Australia is highly influenced by the need for refrigeration and air-conditioning. An extensive literature review has been conducted on the use of phase change materials (PCMs) in thermal storage systems. PCMs use latent heat at the solid-liquid phase transition point to store thermal energy. They are considered to be useful as a thermal energy storage (TES) material because they can provide much higher energy storage densities compared to conventional sensible thermal storage materials. This paper reviewed the main disadvantages of using PCMs for energy storage, such as low heat transfer, super cooling and system design issues. Other issues with PCMs include incongruence and corrosion of heat exchanger surfaces. The authors suggested that in order to address these problems, future research should focus on maximizing heat transfer by optimizing the configuration of the encapsulation through a parametric analysis using a PCM numerical model. The effective conductivity in encapsulated PCMs in a latent heat thermal energy storage (LHTES) system can also be increased by using conductors in the encapsulation that have high thermal conductivity. 47 refs., 1 tab., 1 fig.

Worst-Case Energy Efficiency Maximization in a 5G Massive MIMO-NOMA System.

Science.gov (United States)

Chinnadurai, Sunil; Selvaprabhu, Poongundran; Jeong, Yongchae; Jiang, Xueqin; Lee, Moon Ho

2017-09-18

In this paper, we examine the robust beamforming design to tackle the energy efficiency (EE) maximization problem in a 5G massive multiple-input multiple-output (MIMO)-non-orthogonal multiple access (NOMA) downlink system with imperfect channel state information (CSI) at the base station. A novel joint user pairing and dynamic power allocation (JUPDPA) algorithm is proposed to minimize the inter user interference and also to enhance the fairness between the users. This work assumes imperfect CSI by adding uncertainties to channel matrices with worst-case model, i.e., ellipsoidal uncertainty model (EUM). A fractional non-convex optimization problem is formulated to maximize the EE subject to the transmit power constraints and the minimum rate requirement for the cell edge user. The designed problem is difficult to solve due to its nonlinear fractional objective function. We firstly employ the properties of fractional programming to transform the non-convex problem into its equivalent parametric form. Then, an efficient iterative algorithm is proposed established on the constrained concave-convex procedure (CCCP) that solves and achieves convergence to a stationary point of the above problem. Finally, Dinkelbach's algorithm is employed to determine the maximum energy efficiency. Comprehensive numerical results illustrate that the proposed scheme attains higher worst-case energy efficiency as compared with the existing NOMA schemes and the conventional orthogonal multiple access (OMA) scheme.

Worst-Case Energy Efficiency Maximization in a 5G Massive MIMO-NOMA System

Directory of Open Access Journals (Sweden)

Sunil Chinnadurai

2017-09-01

Full Text Available In this paper, we examine the robust beamforming design to tackle the energy efficiency (EE maximization problem in a 5G massive multiple-input multiple-output (MIMO-non-orthogonal multiple access (NOMA downlink system with imperfect channel state information (CSI at the base station. A novel joint user pairing and dynamic power allocation (JUPDPA algorithm is proposed to minimize the inter user interference and also to enhance the fairness between the users. This work assumes imperfect CSI by adding uncertainties to channel matrices with worst-case model, i.e., ellipsoidal uncertainty model (EUM. A fractional non-convex optimization problem is formulated to maximize the EE subject to the transmit power constraints and the minimum rate requirement for the cell edge user. The designed problem is difficult to solve due to its nonlinear fractional objective function. We firstly employ the properties of fractional programming to transform the non-convex problem into its equivalent parametric form. Then, an efficient iterative algorithm is proposed established on the constrained concave-convex procedure (CCCP that solves and achieves convergence to a stationary point of the above problem. Finally, Dinkelbach’s algorithm is employed to determine the maximum energy efficiency. Comprehensive numerical results illustrate that the proposed scheme attains higher worst-case energy efficiency as compared with the existing NOMA schemes and the conventional orthogonal multiple access (OMA scheme.

Strange Meson Radiative Capture on the Proton in Low Energy QCD Lagrangian

Institute of Scientific and Technical Information of China (English)

ZHOU Li-Juan; MA Wei-Xing

2002-01-01

Based on our low energy QCD Lagrangian description of strange meson photoproduction off the protonand the crossing symmetry, the strange meson radiative capture on the proton, K- + p →γ + A, is investigated in the[SUsF (6) O(3)]sym. SUc (3) quark model of baryon structure with the same input parameter, the only strong couplingconstant aM, as that in the strange meson photoproduction off the proton γ + p → K+ + A, a crossing channel of thecapture reaction. A good agreement on the branching ratio between the predictions and data is obtained successfully.This excellent fit indicates that our low energy QCD Lagrangian theory with only one free parameter is an advancedand unified description of strange meson photoproduction and its associated radiative capture.

Impact of kiln thermal energy demand and false air on cement kiln flue gas CO2 capture

Energy Technology Data Exchange (ETDEWEB)

Arachchige, Udara S.P.R.; Kawan, Dinesh; Tokheim, Lars-Andre [Telemark University College, Porsgrunn (Norway); Melaaen, Morten C. [Telemark University College, Porsgrunn (Norway); (Tel-Tek, Porsgrunn (Norway)

2013-07-01

The present study is focused on the effect of the specific thermal energy demand and the false air factor on carbon capture applied to cement kiln exhaust gases. The carbon capture process model was developed and implemented in Aspen Plus. The model was developed for flue gases from a typical cement clinker manufacturing plant. The specific thermal energy demand as well as the false air factor of the kiln system were varied in order to determine the effect on CO2 capture plant performance, such as the solvent regeneration energy demand. In general, an increase in the mentioned kiln system factors increases the regeneration energy demand. The reboiler energy demand is calculated as 3270, 3428 and 3589 kJ/kg clinker for a specific thermal energy of 3000, 3400 and 3800 kJ/kg clinker, respectively. Setting the false air factor to 25, 50 or 70% gives a reboiler energy demand of 3428, 3476, 3568 kJ/kg clinker, respectively.

Social group utility maximization

CERN Document Server

Gong, Xiaowen; Yang, Lei; Zhang, Junshan

2014-01-01

This SpringerBrief explains how to leverage mobile users' social relationships to improve the interactions of mobile devices in mobile networks. It develops a social group utility maximization (SGUM) framework that captures diverse social ties of mobile users and diverse physical coupling of mobile devices. Key topics include random access control, power control, spectrum access, and location privacy.This brief also investigates SGUM-based power control game and random access control game, for which it establishes the socially-aware Nash equilibrium (SNE). It then examines the critical SGUM-b

The Calcium-Looping technology for CO_2 capture: On the important roles of energy integration and sorbent behavior

International Nuclear Information System (INIS)

Perejón, Antonio; Romeo, Luis M.; Lara, Yolanda; Lisbona, Pilar; Martínez, Ana; Valverde, Jose Manuel

2016-01-01

Highlights: • The Calcium Looping (CaL) technology is a potentially low cost and highly efficient postcombustion CO_2 capture technology. • Energy integration and sorbent behavior play a relevant role on the process. • The industrial competitiveness of the process depends critically on the minimization of energy penalties. • It may be used in precombustion capture systems and other industrial processes such as cement production. • Sorbent deactivation must be assessed under realistic conditions involving high CO_2 concentration in the calciner. - Abstract: The Calcium Looping (CaL) technology, based on the multicyclic carbonation/calcination of CaO in gas–solid fluidized bed reactors at high temperature, has emerged in the last years as a potentially low cost technology for CO_2 capture. In this manuscript a critical review is made on the important roles of energy integration and sorbent behavior in the process efficiency. Firstly, the strategies proposed to reduce the energy demand by internal integration are discussed as well as process modifications aimed at optimizing the overall efficiency by means of external integration. The most important benefit of the high temperature CaL cycles is the possibility of using high temperature streams that could reduce significantly the energy penalty associated to CO_2 capture. The application of the CaL technology in precombustion capture systems and energy integration, and the coupling of the CaL technology with other industrial processes are also described. In particular, the CaL technology has a significant potential to be a feasible CO_2 capture system for cement plants. A precise knowledge of the multicyclic CO_2 capture behavior of the sorbent at the CaL conditions to be expected in practice is of great relevance in order to predict a realistic capture efficiency and energy penalty from process simulations. The second part of this manuscript will be devoted to this issue. Particular emphasis is put on the

Negative meson capture in hydrogen

International Nuclear Information System (INIS)

Baird, T.J.

1977-01-01

The processes of deexcitation and capture of negative mesons and hadrons in atomic hydrogen are investigated. Only slow collisions in which the projectile-atom relative velocity is less than one atomic unit are considered, and the motion of the incident particle is treated classically. For each classical trajectory the probability of ionizing the hydrogen atom is determined, together with the energy spectrum of the emitted electron. Ionization probabilities are calculated using the time-dependent formulation of the perturbed stationary state method. Exact two-center electronic wave functions are used for both bound and continuum states. The total ionization cross section and electron energy spectrum have been calculated for negative muons, kaons and antiprotons at incident relative velocities between 0.04 and 1.0 atomic units. The electron energy spectrum has a sharp peak for electron kinetic energies on the order of 10 -3 Rydbergs. The ionization process thus favors the emission of very slow electrons. The cross section for ionization with capture of the incident particle was calculated for relative kinetic energies greater than 1.0 Rydberg. Since ionization was found to occur with the emission of electrons of nearly zero kinetic energy, the fraction of ionizing collisions which result in capture decreases very rapidly with projectile kinetic energy. The energy distributions of slowed down muons and hadrons were also computed. These distributions were used together with the capture cross section to determine the distribution of kinetic energies at which capture takes place. It was found that most captures occur for kinetic energies slightly less than 1.0 Rydbergs with relatively little capture at thermal energies. The captured particles therefore tend to go into very large and loosely found orbits with binding energies less than 0.1 Rydbergs

Developing maximal neuromuscular power: Part 1--biological basis of maximal power production.

Science.gov (United States)

Cormie, Prue; McGuigan, Michael R; Newton, Robert U

2011-01-01

This series of reviews focuses on the most important neuromuscular function in many sport performances, the ability to generate maximal muscular power. Part 1 focuses on the factors that affect maximal power production, while part 2, which will follow in a forthcoming edition of Sports Medicine, explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability of the neuromuscular system to generate maximal power is affected by a range of interrelated factors. Maximal muscular power is defined and limited by the force-velocity relationship and affected by the length-tension relationship. The ability to generate maximal power is influenced by the type of muscle action involved and, in particular, the time available to develop force, storage and utilization of elastic energy, interactions of contractile and elastic elements, potentiation of contractile and elastic filaments as well as stretch reflexes. Furthermore, maximal power production is influenced by morphological factors including fibre type contribution to whole muscle area, muscle architectural features and tendon properties as well as neural factors including motor unit recruitment, firing frequency, synchronization and inter-muscular coordination. In addition, acute changes in the muscle environment (i.e. alterations resulting from fatigue, changes in hormone milieu and muscle temperature) impact the ability to generate maximal power. Resistance training has been shown to impact each of these neuromuscular factors in quite specific ways. Therefore, an understanding of the biological basis of maximal power production is essential for developing training programmes that effectively enhance maximal power production in the human.

Implementation and Validation of a Self-Consumption Maximization Energy Management Strategy in a Vanadium Redox Flow BIPV Demonstrator

Directory of Open Access Journals (Sweden)

Luis Fialho

2016-06-01

Full Text Available This paper presents the results of the implementation of a self-consumption maximization strategy tested in a real-scale Vanadium Redox Flow Battery (VRFB (5 kW, 60 kWh and Building Integrated Photovoltaics (BIPV demonstrator (6.74 kWp. The tested energy management strategy aims to maximize the consumption of energy generated by a BIPV system through the usage of a battery. Whenever possible, the residual load is either stored in the battery to be used later or is supplied by the energy stored previously. The strategy was tested over seven days in a real-scale VRF battery to assess the validity of this battery to implement BIPV-focused energy management strategies. The results show that it was possible to obtain a self-consumption ratio of 100.0%, and that 75.6% of the energy consumed was provided by PV power. The VRFB was able to perform the strategy, although it was noticed that the available power (either to charge or discharge varied with the state of charge.

High energy resolution measurement of the 238U neutron capture yield in the energy region between 1 and 100 keV

International Nuclear Information System (INIS)

Machlin, R.L.; Perez, R.B.; de Saussure, G.; Ingle, R.W.

1988-01-01

A measurement of the 238 U neutron capture yield was performed at the 150 meter flight-path of the ORELA facility on two 238 U samples (0.01224 and 0.0031 atomsbarn). The capture yeild data were normalized by Moxon's small resonance method. The energy resolution achieved in this measurement frequently resulted in doublet and triplet splittings of what appeared to be single resonance in previous measurements. This resolution should allow extension of the resolved resonance energy region in 238 U from the present 4-keV limit up to 15 or 20 keV incident neutron energy. Some 200 small resonances of the ( 238 U /plus/ n) compound nucleus have been observed which had not been detected in transmission measurement, in the energy range from 250 eV to 10 keV

Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions

Energy Technology Data Exchange (ETDEWEB)

Vlad, Ciprian; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Ceanga, Emil [' ' Dunarea de Jos' ' University of Galati, 47, Domneasca, 800008-Galati (Romania)

2010-02-15

This paper discusses the problem of output power maximization for low-power wind energy conversion systems operated in partial load. These systems are generally based on multi-polar permanent-magnet synchronous generators, who exhibit significant efficiency variations over the operating range. Unlike the high-power systems, whose mechanical-to-electrical conversion efficiency is high and practically does not modify the global optimum, the low-power systems global conversion efficiency is affected by the generator behavior and the electrical power optimization is no longer equivalent with the mechanical power optimization. The system efficiency has been analyzed by using both the maxima locus of the mechanical power versus the rotational speed characteristics, and the maxima locus of the electrical power delivered versus the rotational speed characteristics. The experimental investigation has been carried out by using a torque-controlled generator taken from a real-world wind turbine coupled to a physically simulated wind turbine rotor. The experimental results indeed show that the steady-state performance of the conversion system is strongly determined by the generator behavior. Some control solutions aiming at maximizing the energy efficiency are envisaged and thoroughly compared through experimental results. (author)

Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions

International Nuclear Information System (INIS)

Vlad, Ciprian; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Ceanga, Emil

2010-01-01

This paper discusses the problem of output power maximization for low-power wind energy conversion systems operated in partial load. These systems are generally based on multi-polar permanent-magnet synchronous generators, who exhibit significant efficiency variations over the operating range. Unlike the high-power systems, whose mechanical-to-electrical conversion efficiency is high and practically does not modify the global optimum, the low-power systems global conversion efficiency is affected by the generator behavior and the electrical power optimization is no longer equivalent with the mechanical power optimization. The system efficiency has been analyzed by using both the maxima locus of the mechanical power versus the rotational speed characteristics, and the maxima locus of the electrical power delivered versus the rotational speed characteristics. The experimental investigation has been carried out by using a torque-controlled generator taken from a real-world wind turbine coupled to a physically simulated wind turbine rotor. The experimental results indeed show that the steady-state performance of the conversion system is strongly determined by the generator behavior. Some control solutions aiming at maximizing the energy efficiency are envisaged and thoroughly compared through experimental results.

An Efficient and Effective Design of InP Nanowires for Maximal Solar Energy Harvesting.

Science.gov (United States)

Wu, Dan; Tang, Xiaohong; Wang, Kai; He, Zhubing; Li, Xianqiang

2017-11-25

Solar cells based on subwavelength-dimensions semiconductor nanowire (NW) arrays promise a comparable or better performance than their planar counterparts by taking the advantages of strong light coupling and light trapping. In this paper, we present an accurate and time-saving analytical design for optimal geometrical parameters of vertically aligned InP NWs for maximal solar energy absorption. Short-circuit current densities are calculated for each NW array with different geometrical dimensions under solar illumination. Optimal geometrical dimensions are quantitatively presented for single, double, and multiple diameters of the NW arrays arranged both squarely and hexagonal achieving the maximal short-circuit current density of 33.13 mA/cm 2 . At the same time, intensive finite-difference time-domain numerical simulations are performed to investigate the same NW arrays for the highest light absorption. Compared with time-consuming simulations and experimental results, the predicted maximal short-circuit current densities have tolerances of below 2.2% for all cases. These results unambiguously demonstrate that this analytical method provides a fast and accurate route to guide high performance InP NW-based solar cell design.

Maximized Effective Energy Output of Contact-Separation-Triggered Triboelectric Nanogenerators as Limited by Air Breakdown

KAUST Repository

Zi, Yunlong; Wu, Changsheng; Ding, Wenbo; Wang, Zhong Lin

2017-01-01

Recent progress in triboelectric nanogenerators (TENGs) has demonstrated their promising potential as a high-efficiency mechanical energy harvesting technology, and plenty of effort has been devoted to improving the power output by maximizing the triboelectric surface charge density. However, due to high-voltage air breakdown, most of the enhanced surface charge density brought by material/surface optimization or external ion injection is not retainable or usable for electricity generation during the operation of contact-separation-triggered TENGs. Here, the existence of the air breakdown effect in a contact-separation mode TENG with a low threshold surface charge density of ≈40–50 µC m−2 is first validated under the high impedance external load, and then followed by the theoretical study of the maximized effective energy output as limited by air breakdown for contact-separation-triggered TENGs. The effects of air pressure and gas composition are also studied and propose promising solutions for reducing the air breakdown effect. This research provides a crucial fundamental study for TENG technology and its further development and applications.

Maximized Effective Energy Output of Contact-Separation-Triggered Triboelectric Nanogenerators as Limited by Air Breakdown

KAUST Repository

Zi, Yunlong

2017-05-02

Recent progress in triboelectric nanogenerators (TENGs) has demonstrated their promising potential as a high-efficiency mechanical energy harvesting technology, and plenty of effort has been devoted to improving the power output by maximizing the triboelectric surface charge density. However, due to high-voltage air breakdown, most of the enhanced surface charge density brought by material/surface optimization or external ion injection is not retainable or usable for electricity generation during the operation of contact-separation-triggered TENGs. Here, the existence of the air breakdown effect in a contact-separation mode TENG with a low threshold surface charge density of ≈40–50 µC m−2 is first validated under the high impedance external load, and then followed by the theoretical study of the maximized effective energy output as limited by air breakdown for contact-separation-triggered TENGs. The effects of air pressure and gas composition are also studied and propose promising solutions for reducing the air breakdown effect. This research provides a crucial fundamental study for TENG technology and its further development and applications.

Angular scattering in electron capture and loss D- beam formation processes

International Nuclear Information System (INIS)

Coggiola, M.J.; Hodges, R.V.; Huestis, D.L.; Peterson, J.R.

1980-01-01

The development of high energy (> 150 keV) neutral beams for heating and fueling magnetic fusion devices depends on the ability to produce well-collimated negative ion beams. The double capture charge-exchange technique is a known, scalable method. In order to maximize the overall efficiency of the process and to achieve the desired beam characteristics, it is necessary to examine the optical qualities of the beams as well as the total efficiency of beam production. A combined modeling and experimental study of the angular scattering effects in negative ion formation and loss processes has therefore been undertaken

Gaussian maximally multipartite-entangled states

Science.gov (United States)

Facchi, Paolo; Florio, Giuseppe; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio

2009-12-01

We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7 .

Gaussian maximally multipartite-entangled states

International Nuclear Information System (INIS)

Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio; Lupo, Cosmo; Mancini, Stefano

2009-01-01

We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7.

High energy resolution measurement of the sup 238 U neutron capture yield from 1 to 100 keV

Energy Technology Data Exchange (ETDEWEB)

Macklin, R.L. (Tennessee Univ., Knoxville, TN (United States). Dept. of Nuclear Engineering); Perez, R.B. (Tennessee Univ., Knoxville, TN (United States). Dept. of Nuclear Engineering Oak Ridge National Lab., TN (United States)); De Saussure, G.; Ingle, R.W. (Oak Ridge National Lab., TN (United States))

1991-01-01

The purpose of this work is the precise determination of the {sup 238}U neutron capture yield (i.e. the probability of neutron capture) as a function of neutron energy with the highest available neutron energy resolution. The motivation for this undertaking arises from the central role played by the {sup 238}U neutron capture process in the neutron balance of both thermal reactors and fast breeder reactors. The present measurement was performed using the Oak Ridge Electron Linear Accelerator (ORELA) facility. The pulsed beam of neutrons from the ORELA facility is collimated on a sample of {sup 238}U. The neutron capture rate in the sample is measured, as a function of neutron time-of-flight (TOF) by detecting the {gamma}-rays from the {sup 238}U(n, {gamma}){sup 239}U reaction with a large {gamma}-ray detector surrounding the {sup 238}U sample. At each energy, the capture yield is proportional to the observed capture rate divided by the measured intensity of the neutron beam. The constant of proportionality (the normalization constant) is obtained from the ratio of theoretical to experimentally measured areas under small {sup 238}U resonances where the resonance parameters have been determined from high-resolution {sup 238}U transmission measurements. The cross section for the reaction {sup 238}U(n,{gamma}){sup 239}U can be derived from the measured capture yield if one applies appropriate corrections for multiple scattering and resonance self-shielding. Some 200 {sup 238}U neutron resonances in the energy range from 250 eV to 10 keV have been observed which had not been detected in previous measurements. (author).

Applications of maximally concentrating optics for solar energy collection

Science.gov (United States)

O'Gallagher, J.; Winston, R.

1985-11-01

A new family of optical concentrators based on a general nonimaging design principle for maximizing the geometric concentration, C, for radiation within a given acceptance half angle ±θα has been developed. The maximum limit exceeds by factors of 2 to 10 that attainable by systems using focusing optics. The wide acceptance angles permitted using these techniques have several unique advantages for solar concentrators including the elimination of the diurnal tracking requirement at intermediate concentrations (up to ˜10x), collection of circumsolar and some diffuse radiation, and relaxed tolerances. Because of these advantages, these types of concentrators have applications in solar energy wherever concentration is desired, e.g. for a wide variety of both thermal and photovoltaic uses. The basic principles of nonimaging optical design are reviewed. Selected configurations for thermal collector applications are discussed and the use of nonimaging elements as secondary concentrators is illustrated in the context of higher concentration applications.

A Multi-Hop Energy Neutral Clustering Algorithm for Maximizing Network Information Gathering in Energy Harvesting Wireless Sensor Networks.

Science.gov (United States)

Yang, Liu; Lu, Yinzhi; Zhong, Yuanchang; Wu, Xuegang; Yang, Simon X

2015-12-26

Energy resource limitation is a severe problem in traditional wireless sensor networks (WSNs) because it restricts the lifetime of network. Recently, the emergence of energy harvesting techniques has brought with them the expectation to overcome this problem. In particular, it is possible for a sensor node with energy harvesting abilities to work perpetually in an Energy Neutral state. In this paper, a Multi-hop Energy Neutral Clustering (MENC) algorithm is proposed to construct the optimal multi-hop clustering architecture in energy harvesting WSNs, with the goal of achieving perpetual network operation. All cluster heads (CHs) in the network act as routers to transmit data to base station (BS) cooperatively by a multi-hop communication method. In addition, by analyzing the energy consumption of intra- and inter-cluster data transmission, we give the energy neutrality constraints. Under these constraints, every sensor node can work in an energy neutral state, which in turn provides perpetual network operation. Furthermore, the minimum network data transmission cycle is mathematically derived using convex optimization techniques while the network information gathering is maximal. Simulation results show that our protocol can achieve perpetual network operation, so that the consistent data delivery is guaranteed. In addition, substantial improvements on the performance of network throughput are also achieved as compared to the famous traditional clustering protocol LEACH and recent energy harvesting aware clustering protocols.

A Multi-Hop Energy Neutral Clustering Algorithm for Maximizing Network Information Gathering in Energy Harvesting Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Liu Yang

2015-12-01

Full Text Available Energy resource limitation is a severe problem in traditional wireless sensor networks (WSNs because it restricts the lifetime of network. Recently, the emergence of energy harvesting techniques has brought with them the expectation to overcome this problem. In particular, it is possible for a sensor node with energy harvesting abilities to work perpetually in an Energy Neutral state. In this paper, a Multi-hop Energy Neutral Clustering (MENC algorithm is proposed to construct the optimal multi-hop clustering architecture in energy harvesting WSNs, with the goal of achieving perpetual network operation. All cluster heads (CHs in the network act as routers to transmit data to base station (BS cooperatively by a multi-hop communication method. In addition, by analyzing the energy consumption of intra- and inter-cluster data transmission, we give the energy neutrality constraints. Under these constraints, every sensor node can work in an energy neutral state, which in turn provides perpetual network operation. Furthermore, the minimum network data transmission cycle is mathematically derived using convex optimization techniques while the network information gathering is maximal. Simulation results show that our protocol can achieve perpetual network operation, so that the consistent data delivery is guaranteed. In addition, substantial improvements on the performance of network throughput are also achieved as compared to the famous traditional clustering protocol LEACH and recent energy harvesting aware clustering protocols.

CO{sub 2} capture efficiency and energy requirement analysis of power plant using modified calcium-based sorbent looping cycle

Energy Technology Data Exchange (ETDEWEB)

Li, Y.J.; Zhao, C.S.; Chen, H.C.; Ren, Q.Q.; Duan, L.B. [Southeast University, Nanjing (China). School of Energy & Environment

2011-03-15

This paper examines the average carbonation conversion, CO{sub 2} capture efficiency and energy requirement for post-combustion CO{sub 2} capture system during the modified calcium-based sorbent looping cycle. The limestone modified with acetic acid solution, i.e. calcium acetate is taken as an example of the modified calcium-based sorbents. The modified limestone exhibits much higher average carbonation conversion than the natural sorbent under the same condition. The CO{sub 2} capture efficiency increases with the sorbent flow ratios. Compared with the natural limestone, much less makeup mass flow of the recycled and the fresh sorbent is needed for the system when using the modified limestone at the same CO{sub 2} capture efficiency. Achieving 0.95 of CO{sub 2} capture efficiency without sulfation, 272 kJ/mol CO{sub 2} is required in the calciner for the natural limestone, whereas only 223 kJ/mol CO{sub 2} for the modified sorbent. The modified limestone possesses greater advantages in CO{sub 2} capture efficiency and energy consumption than the natural sorbent. When the sulfation and carbonation of the sorbents take place simultaneously, more energy is required. It is significantly necessary to remove SO{sub 2} from the flue gas before it enters the carbonator in order to reduce energy consumption in the calciner.

Low Mass Printable Devices for Energy Capture, Storage, and Use

Science.gov (United States)

Frazier, Donald O.; Singer, Christopher E.; Rogers, Jan R.; Schramm, Harry F.; Fabisinski, Leo L.; Lowenthal, Mark; Ray, William J.; Fuller, Kirk A.

2010-01-01

The energy-efficient, environmentally friendly technology that will be presented is the result of a Space Act Agreement between NthDegree Technologies Worldwide, Inc., and the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC). The work combines semiconductor and printing technologies to advance lightweight electronic and photonic devices having excellent potential for commercial and exploration applications. Device development involves three projects that relate to energy generation and consumption: (1) a low-mass efficient (low power, low heat emission) micro light-emitting diode (LED) area lighting device; (2) a low-mass omni-directional efficient photovoltaic (PV) device with significantly improved energy capture; and (3) a new approach to building super-capacitors. These three technologies, energy capture, storage, and usage (e.g., lighting), represent a systematic approach for building efficient local micro-grids that are commercially feasible; furthermore, these same technologies, appropriately replacing lighting with lightweight power generation, will be useful for enabling inner planetary missions using smaller launch vehicles and to facilitate surface operations during lunar and planetary surface missions. The PV device model is a two sphere, light trapped sheet approximately 2-mm thick. The model suggests a significant improvement over current thin film systems. For lighting applications, all three technology components are printable in-line by printing sequential layers on a standard screen or flexographic direct impact press using the three-dimensional printing technique (3DFM) patented by NthDegree. One primary contribution to this work in the near term by the MSFC is to test the robustness of prototype devices in the harsh environments that prevail in space and on the lunar surface. It is anticipated that this composite device, of which the lighting component has passed off-gassing testing, will function

Radiative electron capture

International Nuclear Information System (INIS)

Biggerstaff, J.A.; Appleton, B.R.; Datz, S.; Moak, C.D.; Neelavathi, V.N.; Noggle, T.S.; Ritchie, R.H.; VerBeek, H.

1975-01-01

Some data are presented for radiative electron capture by fast moving ions. The radiative electron capture spectrum is shown for O 8+ in Ag, along with the energy dependence of the capture cross-section. A discrepancy between earlier data, theoretical prediction, and the present data is pointed out. (3 figs) (U.S.)

The maximization of the efficiency in the energy conversion in isolated photovoltaic systems; Tecnicas de maxima transferencia de potencia em sistemas fotovoltaicos isolados

Energy Technology Data Exchange (ETDEWEB)

Machado-Neto, L. V. B.; Cabral, C. V. T.; Diniz, A. S. A. C.; Cortizo, P. C.; Oliveira-Filho, D.

2004-07-01

The maximization of the efficiency in the energy conversion is essential into the developing of technical and economic sustainability of photovoltaic solar energy systems. In this paper is realized the study of a power maximization technique for photovoltaic generators. The power maximization technique explored in this paper is the Maximum Power Point Tracking (MPPT). There are different strategies being studied currently; this work consists of the development of an electronic converter prototype for MPPT, including the developing of the tracking algorithm implemented in a microcontroller. It is also realized a simulation of the system and a prototype was assembled and the first results are presented here. (Author)

Carbon captured from the air

International Nuclear Information System (INIS)

Keith, D.

2008-01-01

This article presented an innovative way to achieve the efficient capture of atmospheric carbon. A team of scientists from the University of Calgary's Institute for Sustainable Energy, Environment and Economy have shown that it is possible to reduce carbon dioxide (CO 2 ) using a simple machine that can capture the trace amount of CO 2 present in ambient air at any place on the planet. The thermodynamics of capturing the small concentrations of CO 2 from the air is only slightly more difficult than capturing much larger concentrations of CO 2 from power plants. The research is significant because it offers a way to capture CO 2 emissions from transportation sources such as vehicles and airplanes, which represent more than half of the greenhouse gases emitted on Earth. The energy efficient and cost effective air capture technology could complement other approaches for reducing emissions from the transportation sector, such as biofuels and electric vehicles. Air capture differs from carbon capture and storage (CCS) technology used at coal-fired power plants where CO 2 is captured and pipelined for permanent storage underground. Air capture can capture the CO 2 that is present in ambient air and store it wherever it is cheapest. The team at the University of Calgary showed that CO 2 could be captured directly from the air with less than 100 kWhrs of electricity per tonne of CO 2 . A custom-built tower was able to capture the equivalent of 20 tonnes per year of CO 2 on a single square meter of scrubbing material. The team devised a way to use a chemical process from the pulp and paper industry to cut the energy cost of air capture in half. Although the technology is only in its early stage, it appears that CO 2 could be captured from the air with an energy demand comparable to that needed for CO 2 capture from conventional power plants, but costs will be higher. The simple, reliable and scalable technology offers an opportunity to build a commercial-scale plant. 1 fig

Second-order symmetric eikonal approximation for electron capture at high energies

Energy Technology Data Exchange (ETDEWEB)

Deco, G R; Rivarola, R D [Rosario Univ. Nacional (Argentina). Dept. de Fisica

1985-06-14

A symmetric eikonal approximation for electron capture in ion-atom collisions at high energies has been developed within the Dodd and Greider (1966, Phys. Rev. 146 675) formalism. Implicit intermediate states are included through the choice of distorted initial and final wavefunctions. Explicit intermediate state are considered by the introduction of a free-particle Green's function G/sup +//sub 0/. The model is applied for the resonant charge exchange in H/sup +/+H(1s) collisions. Also, the characteristic dip of the continuum distorted-wave model is analysed when higher orders are included at 'realistic' high energies.

Technical and Energy Performance of an Advanced, Aqueous Ammonia-Based CO2 Capture Technology for a 500 MW Coal-Fired Power Station.

Science.gov (United States)

Li, Kangkang; Yu, Hai; Feron, Paul; Tade, Moses; Wardhaugh, Leigh

2015-08-18

Using a rate-based model, we assessed the technical feasibility and energy performance of an advanced aqueous-ammonia-based postcombustion capture process integrated with a coal-fired power station. The capture process consists of three identical process trains in parallel, each containing a CO2 capture unit, an NH3 recycling unit, a water separation unit, and a CO2 compressor. A sensitivity study of important parameters, such as NH3 concentration, lean CO2 loading, and stripper pressure, was performed to minimize the energy consumption involved in the CO2 capture process. Process modifications of the rich-split process and the interheating process were investigated to further reduce the solvent regeneration energy. The integrated capture system was then evaluated in terms of the mass balance and the energy consumption of each unit. The results show that our advanced ammonia process is technically feasible and energy-competitive, with a low net power-plant efficiency penalty of 7.7%.

Electron capture by multicharged ions from hydrogen atoms at eV energies

International Nuclear Information System (INIS)

Havener, C.C.; Nesnidal, M.P.; Porter, M.R.; Phaneuf, R.A.

1990-01-01

To quantitatively study electron capture during collisions of multiply charged ions with neutral atoms at near-thermal energies, keV-energy multicharged ion beams are merged with ground-state beams of H or D atoms of chosen velocity such that collisions in the relative energy range 1--1000 eV/amu result. Recent data for O 3+ , O 4+ + H(D) are presented and compared with theoretical predictions. Recently completed modifications to the apparatus are described that will provide a significant improvement in signal-to-background and angular collection. These improvements will allow measurements to be extended to lower energies, where effects due to the ion-induced dipole attraction may be evident

Capture, transformation and conversion of the solar energy by the technologies of concentration

International Nuclear Information System (INIS)

Ferriere, A.; Flamant, G.

2003-01-01

The specificities of the solar technologies at concentration are: high energy efficiency with increasing possibilities and the possibility of storage the solar energy by heat for a local and short dated utilization or by chemical storage (hydrogen for instance) for a delayed utilization or far from the capture area. This document takes stock on the concentration solar techniques, the electric power production by concentrated solar energy and the performance of concentrated solar plants, the industrial american experience of the SEGS plants, the hydrogen production by concentrated solar energy and discusses the scientific and technological locks. (A.L.B.)

Commercialization of biomass energy projects: Outline for maximizing use of valuable tax credits and incentives

International Nuclear Information System (INIS)

Sanderson, G.A.

1994-01-01

The Federal Government offers a number of incentives designed specifically to promote biomass energy. These incentives include various tax credits, deductions and exemptions, as well as direct subsidy payments and grants. Additionally, equipment manufacturers and project developers may find several other tax provisions useful, including tax incentives for exporting U.S. good and engineering services, as well as incentives for the development of new technologies. This paper outlines the available incentives, and also addresses ways to coordinate the use of tax breaks with government grants and tax-free bond financing in order to maximize benefits for biomass energy projects

Electron capture in collisions of Si3+ ions with atomic hydrogen from low to intermediate energies

Science.gov (United States)

Liu, C. H.; Liu, L.; Wang, J. G.

2014-07-01

The electron capture process for the Si3+(3s) + H(1s) collisions is investigated by the quantum-mechanical molecular orbital close-coupling (MOCC) method and by the two-center atomic orbital close-coupling (AOCC) method in the energy range of 10-5-10 keV/u and 0.8-200 keV/u, respectively. Total and state-selective cross sections are presented and compared with the available theoretical and experimental results. The present MOCC and AOCC results agree well with the experimental measurements, but show some discrepancy with the calculations of Wang et al. [Phys. Rev. A 74, 052709 (2006), 10.1103/PhysRevA.74.052709] at E > 40 eV/u because of the inclusion of rotational couplings, which play important roles in the electron capture process. At lower energies, the present results are about three to five times smaller than those of Wang et al. due to the difference in the molecular data at large internuclear distances. The energy behaviors of the electron capture cross sections are discussed on the basis of identified reaction mechanisms.

EFFECT OF ENERGY EXPENDITURE AND TRAINING STATUS ON LEPTIN RESPONSE TO SUB-MAXIMAL CYCLING

Directory of Open Access Journals (Sweden)

Anissa Bouassida

2009-06-01

Full Text Available We examined the leptin response and related hormones during and after two sub-maximal exercise protocols in trained and untrained subjects. During this study, plasma concentrations of leptin [Lep], insulin [I], cortisol [C], growth hormone [GH], glucose [G] and lactate [La] were measured. 7 elite volleyball trained players (TR and 7 untrained (UTR subjects (percent body fat: 13.2 ± 1.8 versus 15.7 ± 1.0, p < 0.01, respectively were examined after short and prolonged sub-maximal cycling exercise protocols (SP and PP. Venous blood samples were collected before each protocol, during, at the end, and after 2 and 24 h of recovery. SP and PP energy expenditures ranged from 470 ± 60 to 740 ± 90 kcal for TR and from 450 ± 60 to 710 ± 90 kcal for UTR, respectively. [Lep] was related to body fat percentage and body fat mass in TR (r = 0. 84, p < 0.05 and r = 0.93, p < 0.01 and in UTR (r = 0.89, p < 0.01 and r = 0.92, p < 0. 01, respectively. [Lep] did not change significantly during both protocols for both groups but was lower (p < 0.05 in all sampling in TR when compared to UTR. Plasma [I] decreased (p < 0.01 and [GH] increased (p < 0.01 significantly during both SP and PP and these hormones remained lower (I: p < 0.01 and higher (GH: p < 0.01 than pre-exercise levels after a 2-h recovery period, returning to base-line at 24-h recovery. Plasma [La] increased (p < 0.01 during both protocols for TR and UTR. There was no significant change in [C] and [G] during and after both protocols for all subjects. It is concluded that 1 leptin is not sensitive to acute short or prolonged sub-maximal exercises (with energy expenditure under 800 kcal in volleyball/ anaerobically trained athletes as in untrained subjects, 2 volleyball athletes showed significantly lower resting and exercise leptin response with respect to untrained subjects and 3 it appears that in these anaerobically trained athletes leptin response to exercise is more sensitive to the level of

Probabilities and energies to obtain the counting efficiency of electron-capture nuclides, KLMN model

International Nuclear Information System (INIS)

Casas Galiano, G.; Grau Malonda, A.

1994-01-01

An intelligent computer program has been developed to obtain the mathematical formulae to compute the probabilities and reduced energies of the different atomic rearrangement pathways following electron-capture decay. Creation and annihilation operators for Auger and X processes have been introduced. Taking into account the symmetries associated with each process, 262 different pathways were obtained. This model allows us to obtain the influence of the M-electron-capture in the counting efficiency when the atomic number of the nuclide is high

Probabilities and energies to obtain the counting efficiency of electron-capture nuclides. KLMN model

International Nuclear Information System (INIS)

Galiano, G.; Grau, A.

1994-01-01

An intelligent computer program has been developed to obtain the mathematical formulae to compute the probabilities and reduced energies of the different atomic rearrangement pathways following electron-capture decay. Creation and annihilation operators for Auger and X processes have been introduced. Taking into account the symmetries associated with each process, 262 different pathways were obtained. This model allows us to obtain the influence of the M-electro capture in the counting efficiency when the atomic number of the nuclide is high. (Author)

Gravitational capture

International Nuclear Information System (INIS)

Bondi, H.

1979-01-01

In spite of the strength of gravitational focres between celestial bodies, gravitational capture is not a simple concept. The principles of conservation of linear momentum and of conservation of angular momentum, always impose severe constraints, while conservation of energy and the vital distinction between dissipative and non-dissipative systems allows one to rule out capture in a wide variety of cases. In complex systems especially those without dissipation, long dwell time is a more significant concept than permanent capture. (author)

Radiative neutron capture on a proton at big-bang nucleosynthesis energies

International Nuclear Information System (INIS)

Ando, S.; Cyburt, R. H.; Hong, S. W.; Hyun, C. H.

2006-01-01

The total cross section for radiative neutron capture on a proton, np→dγ, is evaluated at big-bang nucleosynthesis (BBN) energies. The electromagnetic transition amplitudes are calculated up to next-to-leading-order within the framework of pionless effective field theory with dibaryon fields. We also calculate the dγ→np cross section and the photon analyzing power for the dγ(vector sign)→np process from the amplitudes. The values of low-energy constants that appear in the amplitudes are estimated by a Markov Chain Monte Carlo analysis using the relevant low-energy experimental data. Our result agrees well with those of other theoretical calculations except for the np→dγ cross section at some energies estimated by an R-matrix analysis. We also study the uncertainties in our estimation of the np→dγ cross section at relevant BBN energies and find that the estimated cross section is reliable to within ∼1% error

Carbon captured from the air

Energy Technology Data Exchange (ETDEWEB)

Keith, D. [Calgary Univ., AB (Canada)

2008-10-15

This article presented an innovative way to achieve the efficient capture of atmospheric carbon. A team of scientists from the University of Calgary's Institute for Sustainable Energy, Environment and Economy have shown that it is possible to reduce carbon dioxide (CO{sub 2}) using a simple machine that can capture the trace amount of CO{sub 2} present in ambient air at any place on the planet. The thermodynamics of capturing the small concentrations of CO{sub 2} from the air is only slightly more difficult than capturing much larger concentrations of CO{sub 2} from power plants. The research is significant because it offers a way to capture CO{sub 2} emissions from transportation sources such as vehicles and airplanes, which represent more than half of the greenhouse gases emitted on Earth. The energy efficient and cost effective air capture technology could complement other approaches for reducing emissions from the transportation sector, such as biofuels and electric vehicles. Air capture differs from carbon capture and storage (CCS) technology used at coal-fired power plants where CO{sub 2} is captured and pipelined for permanent storage underground. Air capture can capture the CO{sub 2} that is present in ambient air and store it wherever it is cheapest. The team at the University of Calgary showed that CO{sub 2} could be captured directly from the air with less than 100 kWhrs of electricity per tonne of CO{sub 2}. A custom-built tower was able to capture the equivalent of 20 tonnes per year of CO{sub 2} on a single square meter of scrubbing material. The team devised a way to use a chemical process from the pulp and paper industry to cut the energy cost of air capture in half. Although the technology is only in its early stage, it appears that CO{sub 2} could be captured from the air with an energy demand comparable to that needed for CO{sub 2} capture from conventional power plants, but costs will be higher. The simple, reliable and scalable technology

Synchronous generator wind energy conversion control system

Energy Technology Data Exchange (ETDEWEB)

Medeiros, A.L.R. [Wind Energy Group, Recife (Brazil); Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J. [DEE, Campina Grande (Brazil)

1996-12-31

This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

Gradient Dynamics and Entropy Production Maximization

Science.gov (United States)

Janečka, Adam; Pavelka, Michal

2018-01-01

We compare two methods for modeling dissipative processes, namely gradient dynamics and entropy production maximization. Both methods require similar physical inputs-how energy (or entropy) is stored and how it is dissipated. Gradient dynamics describes irreversible evolution by means of dissipation potential and entropy, it automatically satisfies Onsager reciprocal relations as well as their nonlinear generalization (Maxwell-Onsager relations), and it has statistical interpretation. Entropy production maximization is based on knowledge of free energy (or another thermodynamic potential) and entropy production. It also leads to the linear Onsager reciprocal relations and it has proven successful in thermodynamics of complex materials. Both methods are thermodynamically sound as they ensure approach to equilibrium, and we compare them and discuss their advantages and shortcomings. In particular, conditions under which the two approaches coincide and are capable of providing the same constitutive relations are identified. Besides, a commonly used but not often mentioned step in the entropy production maximization is pinpointed and the condition of incompressibility is incorporated into gradient dynamics.

Maximization of energy recovery inside supersonic separator in the presence of condensation and normal shock wave

International Nuclear Information System (INIS)

Shooshtari, S.H. Rajaee; Shahsavand, A.

2017-01-01

Natural gases provide around a quarter of energy consumptions around the globe. Supersonic separators (3S) play multifaceted role in natural gas industry processing, especially for water and hydrocarbon dew point corrections. These states of the art devices have minimum energy requirement and favorable process economy compared to conventional facilities. Their relatively large pressure drops may limit their application in some situations. To maximize the energy recovery of the dew point correction facility, the pressure loss across the 3S unit should be minimized. The optimal structure of 3s unit (including shock wave location and diffuser angle) is selected using simultaneous combination of normal shock occurrence and condensation in the presence of nucleation and growth processes. The condense-free gas enters the non-isentropic normal shock wave. The simulation results indicate that the normal shock location, pressure recovery coefficient and onset position strongly vary up to a certain diffuser angle (β = 8°) with the maximum pressure recovery of 0.88 which leads to minimum potential energy loss. Computational fluid dynamic simulations show that separation of boundary layer does not happen for the computed optimal value of β and it is essentially constant when the inlet gas temperatures and pressures vary over a relatively broad range. - Highlights: • Supersonic separators have found numerous applications in oil and gas industries. • Maximum pressure recovery is crucial for such units to maximize energy efficiency. • Simultaneous condensation and shock wave occurrence are studied for the first time. • Diverging nozzle angle of 8° can provide maximum pressure recovery of 0.88. • The optimal diffuser angle remains constant over a broad range of inlet conditions.

Modelling energy demand of developing countries: Are the specific features adequately captured?

International Nuclear Information System (INIS)

Bhattacharyya, Subhes C.; Timilsina, Govinda R.

2010-01-01

This paper critically reviews existing energy demand forecasting methodologies highlighting the methodological diversities and developments over the past four decades in order to investigate whether the existing energy demand models are appropriate for capturing the specific features of developing countries. The study finds that two types of approaches, econometric and end-use accounting, are commonly used in the existing energy demand models. Although energy demand models have greatly evolved since the early seventies, key issues such as the poor-rich and urban-rural divides, traditional energy resources and differentiation between commercial and non-commercial energy commodities are often poorly reflected in these models. While the end-use energy accounting models with detailed sectoral representations produce more realistic projections as compared to the econometric models, they still suffer from huge data deficiencies especially in developing countries. Development and maintenance of more detailed energy databases, further development of models to better reflect developing country context and institutionalizing the modelling capacity in developing countries are the key requirements for energy demand modelling to deliver richer and more reliable input to policy formulation in developing countries.

Modelling energy demand of developing countries: Are the specific features adequately captured?

Energy Technology Data Exchange (ETDEWEB)

Bhattacharyya, Subhes C. [CEPMLP, University of Dundee, Dundee DD1 4HN (United Kingdom); Timilsina, Govinda R. [Development Research Group, The World Bank, Washington DC (United States)

2010-04-15

This paper critically reviews existing energy demand forecasting methodologies highlighting the methodological diversities and developments over the past four decades in order to investigate whether the existing energy demand models are appropriate for capturing the specific features of developing countries. The study finds that two types of approaches, econometric and end-use accounting, are commonly used in the existing energy demand models. Although energy demand models have greatly evolved since the early seventies, key issues such as the poor-rich and urban-rural divides, traditional energy resources and differentiation between commercial and non-commercial energy commodities are often poorly reflected in these models. While the end-use energy accounting models with detailed sectoral representations produce more realistic projections as compared to the econometric models, they still suffer from huge data deficiencies especially in developing countries. Development and maintenance of more detailed energy databases, further development of models to better reflect developing country context and institutionalizing the modelling capacity in developing countries are the key requirements for energy demand modelling to deliver richer and more reliable input to policy formulation in developing countries. (author)

Laser capture microdissection: Arcturus(XT) infrared capture and UV cutting methods.

Science.gov (United States)

Gallagher, Rosa I; Blakely, Steven R; Liotta, Lance A; Espina, Virginia

2012-01-01

Laser capture microdissection (LCM) is a technique that allows the precise procurement of enriched cell populations from a heterogeneous tissue under direct microscopic visualization. LCM can be used to harvest the cells of interest directly or can be used to isolate specific cells by ablating the unwanted cells, resulting in histologically enriched cell populations. The fundamental components of laser microdissection technology are (a) visualization of the cells of interest via microscopy, (b) transfer of laser energy to a thermolabile polymer with either the formation of a polymer-cell composite (capture method) or transfer of laser energy via an ultraviolet laser to photovolatize a region of tissue (cutting method), and (c) removal of cells of interest from the heterogeneous tissue section. Laser energy supplied by LCM instruments can be infrared (810 nm) or ultraviolet (355 nm). Infrared lasers melt thermolabile polymers for cell capture, whereas ultraviolet lasers ablate cells for either removal of unwanted cells or excision of a defined area of cells. LCM technology is applicable to an array of applications including mass spectrometry, DNA genotyping and loss-of-heterozygosity analysis, RNA transcript profiling, cDNA library generation, proteomics discovery, and signal kinase pathway profiling. This chapter describes the unique features of the Arcturus(XT) laser capture microdissection instrument, which incorporates both infrared capture and ultraviolet cutting technology in one instrument, using a proteomic downstream assay as a model.

Neutron-capture-activation cross sections of 9496Zr and 98100Mo at thermal and 30 keV energy

International Nuclear Information System (INIS)

Wyrick, J.M.; Poenitz, W.P.

1982-01-01

Neutron-capture cross sections of 94 96 Zr and 98 100 Mo were measured relative to the standard-capture cross section of gold at thermal and 30 keV neutron energies using the activation technique. The reported values are based upon available decay-scheme information

New approach to exploit optimally the PV array output energy by maximizing the discharge rate of a directly-coupled photovoltaic water pumping system (DC/PVPS)

International Nuclear Information System (INIS)

Boutelhig, Azzedine; Hadj Arab, Amar; Hanini, Salah

2016-01-01

Highlights: • Mismatches on a designed d-c PV pumping system have been highlighted. • A new approach predicting the maximal discharge has been developed. • The approach has been discussed versus its linearity coefficient. • The approach effectiveness has been investigated and approved. • Theoretical and experimental obtained values have been compared and approved. - Abstract: A directly-coupled photovoltaic water pumping system (DC/PVPS) is generally designed by considering the worst month conditions on lowest daylight-hours, the maximum monthly daily required water volume and tank to store the excess water. In case of absence of hydraulic storage (water tank) or it is not enough dimensioned, the extra amount of pumped water is lost or is not reasonably used, when the system is operated on full daylight-hour. Beside that the extra amount of energy, which might be produced by the PV generator, is not exploited, when the system is operated only during a specified period-time needed to satisfy the demand. Beyond the accurate design that satisfying the end-user, a new approach has been developed as target to exploit maximally the PV array energy production, by maximizing the discharge rate of the system. The methodology consists of approaching maximally the demanded energy to the supplied energy on full operating day. Based on the demand/supply energy condition, the approach has been developed, upon the PV array and the pump performance models. The issued approach predicts the maximum delivery capacity of the system on monthly daily water volumes versus the monthly daily averages of solar irradiation, previously recorded. Its efficacy has been investigated and discussed according to the estimated and experimental values of its linearity coefficient, following the characterization tests of a designed system, carried out at our pumping test facility in Ghardaia (Algeria). The new theoretically and experimentally obtained flow-rates fit well, except

Cross Sections for High-Energy Gamma Transitions from MeV Neutron Capture in {sup 206}Pb

Energy Technology Data Exchange (ETDEWEB)

Bergqvist, I; Lundberg, B; Nilsson, L

1970-03-15

Gamma-ray spectra from neutron capture in Pb (radiogenic lead) in the energy range 1.5 to 8.5 MeV were recorded using time-of-flight techniques. The spectrometer was a Nal (Tl) crystal, 20.8 cm long and 22.6 cm in diameter. The spectra are dominated by gamma transitions to levels with large single-particle strength, in agreement with predictions of semi-direct capture theories. The theories predict enhancements of the direct capture cross section by a factor of 10 - 15 in the region of the giant dipole resonance. The observed enhancement is about 50.

Tri-maximal vs. bi-maximal neutrino mixing

International Nuclear Information System (INIS)

Scott, W.G

2000-01-01

It is argued that data from atmospheric and solar neutrino experiments point strongly to tri-maximal or bi-maximal lepton mixing. While ('optimised') bi-maximal mixing gives an excellent a posteriori fit to the data, tri-maximal mixing is an a priori hypothesis, which is not excluded, taking account of terrestrial matter effects

Maximally-localized position, Euclidean path-integral, and thermodynamics in GUP quantum mechanics

Science.gov (United States)

Bernardo, Reginald Christian S.; Esguerra, Jose Perico H.

2018-04-01

In dealing with quantum mechanics at very high energies, it is essential to adapt to a quasiposition representation using the maximally-localized states because of the generalized uncertainty principle. In this paper, we look at maximally-localized states as eigenstates of the operator ξ = X + iβP that we refer to as the maximally-localized position. We calculate the overlap between maximally-localized states and show that the identity operator can be expressed in terms of the maximally-localized states. Furthermore, we show that the maximally-localized position is diagonal in momentum-space and that the maximally-localized position and its adjoint satisfy commutation and anti-commutation relations reminiscent of the harmonic oscillator commutation and anti-commutation relations. As application, we use the maximally-localized position in developing the Euclidean path-integral and introduce the compact form of the propagator for maximal localization. The free particle momentum-space propagator and the propagator for maximal localization are analytically evaluated up to quadratic-order in β. Finally, we obtain a path-integral expression for the partition function of a thermodynamic system using the maximally-localized states. The partition function of a gas of noninteracting particles is evaluated. At temperatures exceeding the Planck energy, we obtain the gas' maximum internal energy N / 2 β and recover the zero heat capacity of an ideal gas.

Sub-barrier capture with quantum diffusion approach

Directory of Open Access Journals (Sweden)

Scheid W.

2011-10-01

Full Text Available With the quantum diffusion approach the behavior of capture cross sections and mean-square angular momenta of captured systems are revealed in the reactions with deformed and spherical nuclei at sub-barrier energies. With decreasing bombarding energy under the barrier the external turning point of the nucleus-nucleus potential leaves the region of short-range nuclear interaction and action of friction. Because of this change of the regime of interaction, an unexpected enhancement of the capture cross section is found at bombarding energies far below the Coulomb barrier. This effect is shown its worth in the dependence of mean-square angular momentum on the bombarding energy. From the comparison of calculated capture cross sections and experimental capture or fusion cross sections the importance of quasifission near the entrance channel is demonstrated for the actinidebased reactions and reactions with medium-heavy nuclei at extreme sub-barrier energies.

CO2 Capture and Reuse

International Nuclear Information System (INIS)

Thambimuthu, K.; Gupta, M.; Davison, J.

2003-01-01

CO2 capture and storage including its utilization or reuse presents an opportunity to achieve deep reductions in greenhouse gas emissions from fossil energy use. The development and deployment of this option could significantly assist in meeting a future goal of achieving stabilization of the presently rising atmospheric concentration of greenhouse gases. CO2 capture from process streams is an established concept that has achieved industrial practice. Examples of current applications include the use of primarily, solvent based capture technologies for the recovery of pure CO2 streams for chemical synthesis, for utilization as a food additive, for use as a miscible agent in enhanced oil recovery operations and removal of CO2 as an undesired contaminant from gaseous process streams for the production of fuel gases such as hydrogen and methane. In these applications, the technologies deployed for CO2 capture have focused on gas separation from high purity, high pressure streams and in reducing (or oxygen deficient) environments, where the energy penalties and cost for capture are moderately low. However, application of the same capture technologies for large scale abatement of greenhouse gas emissions from fossil fuel use poses significant challenges in achieving (at comparably low energy penalty and cost) gas separation in large volume, dilute concentration and/or low pressure flue gas streams. This paper will focus on a review of existing commercial methods of CO2 capture and the technology stretch, process integration and energy system pathways needed for their large scale deployment in fossil fueled processes. The assessment of potential capture technologies for the latter purpose will also be based on published literature data that are both 'transparent' and 'systematic' in their evaluation of the overall cost and energy penalties of CO2 capture. In view of the of the fact that many of the existing commercial processes for CO2 capture have seen applications in

Vortex-Breakdown-Induced Particle Capture in Branching Junctions.

Science.gov (United States)

Ault, Jesse T; Fani, Andrea; Chen, Kevin K; Shin, Sangwoo; Gallaire, François; Stone, Howard A

2016-08-19

We show experimentally that a flow-induced, Reynolds number-dependent particle-capture mechanism in branching junctions can be enhanced or eliminated by varying the junction angle. In addition, numerical simulations are used to show that the features responsible for this capture have the signatures of classical vortex breakdown, including an approach flow aligned with the vortex axis and a pocket of subcriticality. We show how these recirculation regions originate and evolve and suggest a physical mechanism for their formation. Furthermore, comparing experiments and numerical simulations, the presence of vortex breakdown is found to be an excellent predictor of particle capture. These results inform the design of systems in which suspended particle accumulation can be eliminated or maximized.

Integration of carbon capture and sequestration and renewable resource technologies for sustainable energy supply in the transportation sector

International Nuclear Information System (INIS)

Kim, Minsoo; Won, Wangyun; Kim, Jiyong

2017-01-01

Highlights: • Integration of carbon capture and sequestration and renewable resource technologies. • A new superstructure-based optimization model to identify the energy supply system. • Model validation via application study of the future transportation sector in Korea. - Abstract: In this study, a new design for a sustainable energy system was developed by integrating two technology frameworks: the renewable resource-based energy supply and the conventional (fossil fuel) resource-based energy production coupled with carbon capture and sequestration. To achieve this goal, a new superstructure-based optimization model was proposed using mixed-integer linear programming to identify the optimal combination of these technologies that minimizes the total daily cost, subject to various practical and logical constraints. The performance of the proposed model was validated via an application study of the future transportation sector in Korea. By considering six different scenarios that combined varying crude oil/natural gas prices and environmental regulation options, the optimal configuration of the energy supply system was identified, and the major cost drivers and their sensitivities were analyzed. It was shown that conventional resource-based energy production was preferred if crude oil and natural gas prices were low, even though environmental regulation was considered. Environmental regulation caused an increase in the total daily cost by an average of 26.4%, mainly due to CO_2 capture cost.

Hopewell Beneficial CO2 Capture for Production of Fuels, Fertilizer and Energy

Energy Technology Data Exchange (ETDEWEB)

UOP; Honeywell Resins & Chemicals; Honeywell Process Solutions; Aquaflow Bionomics Ltd

2010-09-30

For Phase 1 of this project, the Hopewell team developed a detailed design for the Small Scale Pilot-Scale Algal CO2 Sequestration System. This pilot consisted of six (6) x 135 gallon cultivation tanks including systems for CO2 delivery and control, algal cultivation, and algal harvesting. A feed tank supplied Hopewell wastewater to the tanks and a receiver tank collected the effluent from the algal cultivation system. The effect of environmental parameters and nutrient loading on CO2 uptake and sequestration into biomass were determined. Additionally the cost of capturing CO2 from an industrial stack emission at both pilot and full-scale was determined. The engineering estimate evaluated Amine Guard technology for capture of pure CO2 and direct stack gas capture and compression. The study concluded that Amine Guard technology has lower lifecycle cost at commercial scale, although the cost of direct stack gas capture is lower at the pilot scale. Experiments conducted under high concentrations of dissolved CO2 did not demonstrate enhanced algae growth rate. This result suggests that the dissolved CO2 concentration at neutral pH was already above the limiting value. Even though dissolved CO2 did not show a positive effect on biomass growth, controlling its value at a constant set-point during daylight hours can be beneficial in an algae cultivation stage with high algae biomass concentration to maximize the rate of CO2 uptake. The limited enhancement of algal growth by CO2 addition to Hopewell wastewater was due at least in part to the high endogenous CO2 evolution from bacterial degradation of dissolved organic carbon present at high levels in the wastewater. It was found that the high level of bacterial activity was somewhat inhibitory to algal growth in the Hopewell wastewater. The project demonstrated that the Honeywell automation and control system, in combination with the accuracy of the online pH, dissolved O2, dissolved CO2, turbidity, Chlorophyll A and

Techno-economic prospects for CO2 capture from distributed energy systems, , 19(March 2013), 2013, pp. 328-347

NARCIS (Netherlands)

Kuramochi, T.; Ramirez, C.A.; Turkenburg, W.C.; Faaij, A.P.C.

2013-01-01

CO2 emissions from distributed energy systems are expected to become increasingly significant, accounting for about 20% for current global energy-related CO2 emissions in 2030. This article reviews, assesses and compares the techno-economic performance of CO2 capture from distributed energy systems

Integration between a demo size post-combustion CO2 capture and full size power plant: an integral approach on energy penalty for different process options

NARCIS (Netherlands)

Miguel Mercader, F. de; Magneschi, G.; Sanchez Fernandez, E.; Stienstra, G.J.; Goetheer, E.L.V.

2012-01-01

CO2 capture based on post-combustion capture has the potential to significantly reduce the CO2 emissions from coal-fired power plants. However, this capture process reduces considerably the energy efficiency of the power plant. To reduce this energy penalty, this paper studies different

Advanced modeling to accelerate the scale up of carbon capture technologies

Energy Technology Data Exchange (ETDEWEB)

Miller, David C.; Sun, XIN; Storlie, Curtis B.; Bhattacharyya, Debangsu

2015-06-01

In order to help meet the goals of the DOE carbon capture program, the Carbon Capture Simulation Initiative (CCSI) was launched in early 2011 to develop, demonstrate, and deploy advanced computational tools and validated multi-scale models to reduce the time required to develop and scale-up new carbon capture technologies. This article focuses on essential elements related to the development and validation of multi-scale models in order to help minimize risk and maximize learning as new technologies progress from pilot to demonstration scale.

Interatomic Coulombic electron capture

International Nuclear Information System (INIS)

Gokhberg, K.; Cederbaum, L. S.

2010-01-01

In a previous publication [K. Gokhberg and L. S. Cederbaum, J. Phys. B 42, 231001 (2009)] we presented the interatomic Coulombic electron capture process--an efficient electron capture mechanism by atoms and ions in the presence of an environment. In the present work we derive and discuss the mechanism in detail. We demonstrate thereby that this mechanism belongs to a family of interatomic electron capture processes driven by electron correlation. In these processes the excess energy released in the capture event is transferred to the environment and used to ionize (or to excite) it. This family includes the processes where the capture is into the lowest or into an excited unoccupied orbital of an atom or ion and proceeds in step with the ionization (or excitation) of the environment, as well as the process where an intermediate autoionizing excited resonance state is formed in the capturing center which subsequently deexcites to a stable state transferring its excess energy to the environment. Detailed derivation of the asymptotic cross sections of these processes is presented. The derived expressions make clear that the environment assisted capture processes can be important for many systems. Illustrative examples are presented for a number of model systems for which the data needed to construct the various capture cross sections are available in the literature.

Variable-speed wind power system with improved energy capture via multilevel conversion

Science.gov (United States)

Erickson, Robert W.; Al-Naseem, Osama A.; Fingersh, Lee Jay

2005-05-31

A system and method for efficiently capturing electrical energy from a variable-speed generator are disclosed. The system includes a matrix converter using full-bridge, multilevel switch cells, in which semiconductor devices are clamped to a known constant DC voltage of a capacitor. The multilevel matrix converter is capable of generating multilevel voltage wave waveform of arbitrary magnitude and frequencies. The matrix converter can be controlled by using space vector modulation.

Ultralow energy calibration of LUX detector using Xe 127 electron capture

Science.gov (United States)

Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Druszkiewicz, E.; Edwards, B. N.; Fallon, S. R.; Fan, A.; Fiorucci, S.; Gaitskell, R. J.; Genovesi, J.; Ghag, C.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.

2017-12-01

We report an absolute calibration of the ionization yields (Qy ) and fluctuations for electronic recoil events in liquid xenon at discrete energies between 186 eV and 33.2 keV. The average electric field applied across the liquid xenon target is 180 V /cm . The data are obtained using low energy Xe 127 electron capture decay events from the 95.0-day first run from LUX (WS2013) in search of weakly interacting massive particles. The sequence of gamma-ray and x-ray cascades associated with I 127 deexcitations produces clearly identified two-vertex events in the LUX detector. We observe the K-(binding energy, 33.2 keV), L-(5.2 keV), M-(1.1 keV), and N-(186 eV) shell cascade events and verify that the relative ratio of observed events for each shell agrees with calculations. The N-shell cascade analysis includes single extracted electron (SE) events and represents the lowest-energy electronic recoil in situ measurements that have been explored in liquid xenon.

Single maximal versus combination punch kinematics.

Science.gov (United States)

Piorkowski, Barry A; Lees, Adrian; Barton, Gabor J

2011-03-01

The aim of this study was to determine the influence of punch type (Jab, Cross, Lead Hook and Reverse Hook) and punch modality (Single maximal, 'In-synch' and 'Out of synch' combination) on punch speed and delivery time. Ten competition-standard volunteers performed punches with markers placed on their anatomical landmarks for 3D motion capture with an eight-camera optoelectronic system. Speed and duration between key moments were computed. There were significant differences in contact speed between punch types (F(2,18,84.87) = 105.76, p = 0.001) with Lead and Reverse Hooks developing greater speed than Jab and Cross. There were significant differences in contact speed between punch modalities (F(2,64,102.87) = 23.52, p = 0.001) with the Single maximal (M+/- SD: 9.26 +/- 2.09 m/s) higher than 'Out of synch' (7.49 +/- 2.32 m/s), 'In-synch' left (8.01 +/- 2.35 m/s) or right lead (7.97 +/- 2.53 m/s). Delivery times were significantly lower for Jab and Cross than Hook. Times were significantly lower 'In-synch' than a Single maximal or 'Out of synch' combination mode. It is concluded that a defender may have more evasion-time than previously reported. This research could be of use to performers and coaches when considering training preparations.

Maximizing Energy Savings Reliability in BC Hydro Industrial Demand-side Management Programs: An Assessment of Performance Incentive Models

Science.gov (United States)

Gosman, Nathaniel

For energy utilities faced with expanded jurisdictional energy efficiency requirements and pursuing demand-side management (DSM) incentive programs in the large industrial sector, performance incentive programs can be an effective means to maximize the reliability of planned energy savings. Performance incentive programs balance the objectives of high participation rates with persistent energy savings by: (1) providing financial incentives and resources to minimize constraints to investment in energy efficiency, and (2) requiring that incentive payments be dependent on measured energy savings over time. As BC Hydro increases its DSM initiatives to meet the Clean Energy Act objective to reduce at least 66 per cent of new electricity demand with DSM by 2020, the utility is faced with a higher level of DSM risk, or uncertainties that impact the costeffective acquisition of planned energy savings. For industrial DSM incentive programs, DSM risk can be broken down into project development and project performance risks. Development risk represents the project ramp-up phase and is the risk that planned energy savings do not materialize due to low customer response to program incentives. Performance risk represents the operational phase and is the risk that planned energy savings do not persist over the effective measure life. DSM project development and performance risks are, in turn, a result of industrial economic, technological and organizational conditions, or DSM risk factors. In the BC large industrial sector, and characteristic of large industrial sectors in general, these DSM risk factors include: (1) capital constraints to investment in energy efficiency, (2) commodity price volatility, (3) limited internal staffing resources to deploy towards energy efficiency, (4) variable load, process-based energy saving potential, and (5) a lack of organizational awareness of an operation's energy efficiency over time (energy performance). This research assessed the capacity

Maximize the operating profit of a SWRO-PRO integrated process for optimal water production and energy recovery

KAUST Repository

Wan, Chun Feng; Chung, Neal Tai-Shung

2016-01-01

Pressure retarded osmosis (PRO) is a promising technology to reduce the specific energy consumption and the operating expenditure of a seawater reverse osmosis (SWRO) plant. In this study, a simple analytical PRO model is developed to predict the PRO performance as the dilution of draw solutions occurs. The model can predict the PRO performance with a high accuracy without carrying out complicated integrations and experiments. The operating profit of SWRO-PRO is also studied by calculating the profit generated for every m3 of seawater entering the process because maximizing the operating profit is the uttermost objective of the SWRO-PRO process. Based on the PRO analytical model, the operating profit and the dynamics of the SWRO-PRO process, a strategy has been proposed to maximize the operating profit of the SWRO-PRO process while maintaining the highest power density of the PRO membranes. This study proves that integration of SWRO with PRO can (1) push the SWRO to a higher recovery and maintain its high profitability, (2) effectively reduce the specific energy consumption of desalination by up to 35% and (3) increase the operating profit up to 100%. © 2016 Elsevier Ltd.

Maximize the operating profit of a SWRO-PRO integrated process for optimal water production and energy recovery

KAUST Repository

Wan, Chun Feng

2016-03-28

Pressure retarded osmosis (PRO) is a promising technology to reduce the specific energy consumption and the operating expenditure of a seawater reverse osmosis (SWRO) plant. In this study, a simple analytical PRO model is developed to predict the PRO performance as the dilution of draw solutions occurs. The model can predict the PRO performance with a high accuracy without carrying out complicated integrations and experiments. The operating profit of SWRO-PRO is also studied by calculating the profit generated for every m3 of seawater entering the process because maximizing the operating profit is the uttermost objective of the SWRO-PRO process. Based on the PRO analytical model, the operating profit and the dynamics of the SWRO-PRO process, a strategy has been proposed to maximize the operating profit of the SWRO-PRO process while maintaining the highest power density of the PRO membranes. This study proves that integration of SWRO with PRO can (1) push the SWRO to a higher recovery and maintain its high profitability, (2) effectively reduce the specific energy consumption of desalination by up to 35% and (3) increase the operating profit up to 100%. © 2016 Elsevier Ltd.

Asynchronous beating of cilia enhances particle capture rate

Science.gov (United States)

Ding, Yang; Kanso, Eva

2014-11-01

Many aquatic micro-organisms use beating cilia to generate feeding currents and capture particles in surrounding fluids. One of the capture strategies is to ``catch up'' with particles when a cilium is beating towards the overall flow direction (effective stroke) and intercept particles on the downstream side of the cilium. Here, we developed a 3D computational model of a cilia band with prescribed motion in a viscous fluid and calculated the trajectories of the particles with different sizes in the fluid. We found an optimal particle diameter that maximizes the capture rate. The flow field and particle motion indicate that the low capture rate of smaller particles is due to the laminar flow in the neighbor of the cilia, whereas larger particles have to move above the cilia tips to get advected downstream which decreases their capture rate. We then analyzed the effect of beating coordination between neighboring cilia on the capture rate. Interestingly, we found that asynchrony of the beating of the cilia can enhance the relative motion between a cilium and the particles near it and hence increase the capture rate.

An Optimal Control Method for Maximizing the Efficiency of Direct Drive Ocean Wave Energy Extraction System

Science.gov (United States)

Chen, Zhongxian; Yu, Haitao; Wen, Cheng

2014-01-01

The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability. PMID:25152913

An optimal control method for maximizing the efficiency of direct drive ocean wave energy extraction system.

Science.gov (United States)

Chen, Zhongxian; Yu, Haitao; Wen, Cheng

2014-01-01

The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability.

Power maximization of variable-speed variable-pitch wind turbines using passive adaptive neural fault tolerant control

Science.gov (United States)

Habibi, Hamed; Rahimi Nohooji, Hamed; Howard, Ian

2017-09-01

Power maximization has always been a practical consideration in wind turbines. The question of how to address optimal power capture, especially when the system dynamics are nonlinear and the actuators are subject to unknown faults, is significant. This paper studies the control methodology for variable-speed variable-pitch wind turbines including the effects of uncertain nonlinear dynamics, system fault uncertainties, and unknown external disturbances. The nonlinear model of the wind turbine is presented, and the problem of maximizing extracted energy is formulated by designing the optimal desired states. With the known system, a model-based nonlinear controller is designed; then, to handle uncertainties, the unknown nonlinearities of the wind turbine are estimated by utilizing radial basis function neural networks. The adaptive neural fault tolerant control is designed passively to be robust on model uncertainties, disturbances including wind speed and model noises, and completely unknown actuator faults including generator torque and pitch actuator torque. The Lyapunov direct method is employed to prove that the closed-loop system is uniformly bounded. Simulation studies are performed to verify the effectiveness of the proposed method.

An integrative approach to the Carbon Capture and Storage (CCS) technologies inside a Water-Energy Nexus Framework

NARCIS (Netherlands)

Vaca Jiménez, Santiago David; Nonhebel, Sanderine; Dijkema, Gerhard

2016-01-01

The energy sector is a major source of the anthropogenic CO2 emissions. Therefore, the sector’s de-carbonization is imperative if we intend to curb the progression of Climate Change. Carbon Capture and Storage (CCS) was created in an attempt to reduce the carbon footprint of energy production.

The role of Carbon Capture and Storage in a future sustainable energy system

DEFF Research Database (Denmark)

Lund, Henrik; Mathiesen, Brian Vad

2012-01-01

systems, the number of utilisation hours of power and CHP plants will have to decrease substantially due to the energy efficiency measures in combination with the inclusion of renewable energy power inputs from wind and similar resources. Consequently, no power or CHP plants exist in future sustainable......This paper presents the results of adding a CCS(Carbon Capture and Storage) plant including an underground CO2 storage to a well described and well documented vision of converting the present Danish fossil based energy system into a future sustainable energy system made by the Danish Society...... huge construction costs with the expectation of long lifetimes. Consequently, the CCS has to operate as part of large-scale power or CHP plants with high utilisation hours for the CCS investment to come even close to being feasible. However, seen in the light of transforming to sustainable energy...

Proton capture by magnetic monopoles

International Nuclear Information System (INIS)

Olaussen, K.; Olsen, H.A.; Oeverboe, I.; Osland, P.

1983-09-01

In the Kazama-Yang approximation, the lowest monopole-proton bound states have binding energies of 938 MeV, 263 keV, 105 eV, and 0.04 eV. The cross section for radiative capture to these states is for velocities β = 10 -5 - 10 -3 found to be of the order of 10 -28 - 10 -26 cm 2 . For the state that has a binding energy of 263 keV, the capture length in water is 171 x (β/10 -4 )sup(0.48) m. Observation of photons from the capture process would indicate the presence of monopoles. (orig.)

Wind Farm Active Power Dispatch for Output Power Maximizing Based on a Wind Turbine Control Strategy for Load Minimizing

DEFF Research Database (Denmark)

Zhang, Baohua; Hu, Weihao; Hou, Peng

2015-01-01

Inclusion of the wake effect in the wind farm control design (WF) can increase the total captured power by wind turbines (WTs), which is usually implemented by derating upwind WTs. However, derating the WT without a proper control strategy will increase the structural loads, caused by operation...... in stall mode. Therefore, the WT control strategy for derating operation should be considered in the attempt at maximizing the total captured power while reducing structural loads. Moreover, electrical power loss on the transmission system inside a WF is also not negligible for maximizing the total output...... power of the WF. In this paper, an optimal active power dispatch strategy based on a WT derating strategy and considering the transmission loss is proposed for maximizing the total output power. The active power reference of each WT is chosen as the optimization variable. A partial swarm optimizing...

On Maximizing the Lifetime of Wireless Sensor Networks by Optimally Assigning Energy Supplies

Science.gov (United States)

Asorey-Cacheda, Rafael; García-Sánchez, Antonio Javier; García-Sánchez, Felipe; García-Haro, Joan; Gonzalez-Castaño, Francisco Javier

2013-01-01

The extension of the network lifetime of Wireless Sensor Networks (WSN) is an important issue that has not been appropriately solved yet. This paper addresses this concern and proposes some techniques to plan an arbitrary WSN. To this end, we suggest a hierarchical network architecture, similar to realistic scenarios, where nodes with renewable energy sources (denoted as primary nodes) carry out most message delivery tasks, and nodes equipped with conventional chemical batteries (denoted as secondary nodes) are those with less communication demands. The key design issue of this network architecture is the development of a new optimization framework to calculate the optimal assignment of renewable energy supplies (primary node assignment) to maximize network lifetime, obtaining the minimum number of energy supplies and their node assignment. We also conduct a second optimization step to additionally minimize the number of packet hops between the source and the sink. In this work, we present an algorithm that approaches the results of the optimization framework, but with much faster execution speed, which is a good alternative for large-scale WSN networks. Finally, the network model, the optimization process and the designed algorithm are further evaluated and validated by means of computer simulation under realistic conditions. The results obtained are discussed comparatively. PMID:23939582

On Maximizing the Lifetime of Wireless Sensor Networks by Optimally Assigning Energy Supplies

Directory of Open Access Journals (Sweden)

Francisco Javier González-Castano

2013-08-01

Full Text Available The extension of the network lifetime of Wireless Sensor Networks (WSN is an important issue that has not been appropriately solved yet. This paper addresses this concern and proposes some techniques to plan an arbitrary WSN. To this end, we suggest a hierarchical network architecture, similar to realistic scenarios, where nodes with renewable energy sources (denoted as primary nodes carry out most message delivery tasks, and nodes equipped with conventional chemical batteries (denoted as secondary nodes are those with less communication demands. The key design issue of this network architecture is the development of a new optimization framework to calculate the optimal assignment of renewable energy supplies (primary node assignment to maximize network lifetime, obtaining the minimum number of energy supplies and their node assignment. We also conduct a second optimization step to additionally minimize the number of packet hops between the source and the sink. In this work, we present an algorithm that approaches the results of the optimization framework, but with much faster execution speed, which is a good alternative for large-scale WSN networks. Finally, the network model, the optimization process and the designed algorithm are further evaluated and validated by means of computer simulation under realistic conditions. The results obtained are discussed comparatively.

Capturing Inter-Annual Variability of PV Energy Production in South Asia

Energy Technology Data Exchange (ETDEWEB)

Lopez, Anthony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maclaurin, Galen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Roberts, Billy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Rosenlieb, Evan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-08-25

Long-term variability of solar resource is an important factor in planning a utility-scale photovoltaic (PV) generation plant, and annual generation for a given location can vary significantly from year to year. Based on multiple years of solar irradiance data, an exceedance probability is the amount of energy that could potentially be produced by a power plant in any given year. An exceedance probability accounts for long-term variability and climate cycles (e.g., monsoons or changes in aerosols), which ultimately impact PV energy generation. Study results indicate that a significant bias could be associated with relying solely on typical meteorological year (TMY) resource data to capture long-term variability. While the TMY tends to under-predict annual generation overall compared to the P50, there appear to be pockets of over-prediction as well.

Implications of net energy-return-on-investment for a low-carbon energy transition

Science.gov (United States)

King, Lewis C.; van den Bergh, Jeroen C. J. M.

2018-04-01

Low-carbon energy transitions aim to stay within a carbon budget that limits potential climate change to 2 °C—or well below—through a substantial growth in renewable energy sources alongside improved energy efficiency and carbon capture and storage. Current scenarios tend to overlook their low net energy returns compared to the existing fossil fuel infrastructure. Correcting from gross to net energy, we show that a low-carbon transition would probably lead to a 24-31% decline in net energy per capita by 2050, which implies a strong reversal of the recent rising trends of 0.5% per annum. Unless vast end-use efficiency savings can be achieved in the coming decades, current lifestyles might be impaired. To maintain the present net energy returns, solar and wind renewable power sources should grow two to three times faster than in other proposals. We suggest a new indicator, `energy return on carbon', to assist in maximizing the net energy from the remaining carbon budget.

The thermodynamics of direct air capture of carbon dioxide

International Nuclear Information System (INIS)

Lackner, Klaus S.

2013-01-01

An analysis of thermodynamic constraints shows that the low concentration of carbon dioxide in ambient air does not pose stringent limits on air capture economics. The thermodynamic energy requirement is small even using an irreversible sorbent-based process. A comparison to flue gas scrubbing suggests that the additional energy requirement is small and can be supplied with low-cost energy. In general, the free energy expended in the regeneration of a sorbent will exceed the free energy of mixing, as absorption is usually not reversible. The irreversibility, which grows with the depth of scrubbing, tends to affect flue gas scrubbing more than air capture which can successfully operate while extracting only a small fraction of the carbon dioxide available in air. This is reflected in a significantly lower theoretical thermodynamic efficiency for a single stage flue gas scrubber than for an air capture device, but low carbon dioxide concentration in air still results in a larger energy demand for air capture. The energy required for capturing carbon dioxide from air could be delivered in various ways. I analyze a thermal swing and also a previously described moisture swing which is driven by the evaporation of water. While the total amount of heat supplied for sorbent regeneration in a thermal swing, in accordance with Carnot's principle, exceeds the total free energy requirement, the additional free energy required as one moves from flue gas scrubbing to air capture can be paid with an amount of additional low grade heat that equals the additional free energy requirement. Carnot's principle remains satisfied because the entire heat supplied, not just the additional amount, must be delivered at a slightly higher temperature. Whether the system is driven by water evaporation or by low grade heat, the cost of the thermodynamically-required energy can be as small as $1 to $2 per metric ton of carbon dioxide. Thermodynamics does not pose a practical constraint on the

Energy conversion performance of black liquor gasification to hydrogen production using direct causticization with CO(2) capture.

Science.gov (United States)

Naqvi, M; Yan, J; Dahlquist, E

2012-04-01

This paper estimates potential hydrogen production via dry black liquor gasification system with direct causticization integrated with a reference pulp mill. The advantage of using direct causticization is elimination of energy intensive lime kiln. Pressure swing adsorption is integrated in the carbon capture process for hydrogen upgrading. The energy conversion performance of the integrated system is compared with other bio-fuel alternatives and evaluated based on system performance indicators. The results indicated a significant hydrogen production potential (about 141MW) with an energy ratio of about 0.74 from the reference black liquor capacity (about 243.5MW) and extra biomass import (about 50MW) to compensate total energy deficit. About 867,000tonnes of CO(2) abatement per year is estimated i.e. combining CO(2) capture and CO(2) offset from hydrogen replacing motor gasoline. The hydrogen production offers a substantial motor fuel replacement especially in regions with large pulp and paper industry e.g. about 63% of domestic gasoline replacement in Sweden. Copyright © 2012 Elsevier Ltd. All rights reserved.

Electron capture in very low energy collisions of multicharged ions with H and D in merged beams

International Nuclear Information System (INIS)

Havener, C.C.; Meyer, F.W.; Phaneuf, R.A.

1991-01-01

An ion-atom merged-beams technique is being used to measure total absolute electron-capture cross sections for multicharged ions in collisions with H (or D) in the energy range between 0.1 and 1000 eV/amu. Comparison between experiment and theory over such a large energy range constitutes a critical test for both experiment and theory. Total capture cross-section measurements for O 3+ H(D) and O 5+ + H(D) are presented and compared to state selective and differential cross section calculations. Landau-Zener calculations show that for O 5+ the sharp increase in the measured cross section below 1 eV/amu is partly due to trajectory effects arising from the ion-induced dipole interaction between the reactants. 20 refs., 8 figs

Removal of nonorthogonality in the Born theory used for study of electron capture in high energy ion-atom collisions

International Nuclear Information System (INIS)

Kimura, M.

1989-01-01

We show the complete removal of the nonorthogonality of wave functions between initial and final states in the Born theory. Hence, this treatment offers more realistic electron capture cross sections in high energy ion-atom collisions. Representative results for resonant electron capture in H + + H collision are discussed in conjunction with other perturbative results. 10 refs., 1 fig

Measurement of the 232Th capture cross section in the energy region 5 keV-150 keV

International Nuclear Information System (INIS)

Lobo, G.; Schillebeeckx, P.; Brusegan, A.; Borella, A.; Corvi, F.; Janeva, N.; Volev, K.

2003-01-01

The 232 Th(n,γ) neutron capture cross-section is of great importance for accelerator driven reactor (ADS) systems based on the Thorium-Uranium fuel cycle. An analysis of the required nuclear data, reveals that the status of the 232 Th capture data is far from the requested 2 % uncertainty level. Recently 232 Th average capture measurements, between 5-200 keV neutron energy, were performed at the FzK Karlsruhe (DE). A comparison of the measured averaged capture cross section with the evaluated data files shows a reasonable agreement in the neutron energy range above 15 keV. However, discrepancies of up to 40 % at lower neutron energies are observed. The same order of discrepancies is observed when comparing their results with the results obtained by Macklin et al. at ORELA. To clarify these discrepancies we measured at IRMM the average capture cross-section at the GEel LINear Accelerator (GELINA). The measurements were performed at a 14.37 m flight-path using the Time-Of-Flight (TOF) method. The gamma rays, originating from the 232 Th(n,γ) reaction, were detected by a pair of C 6 D 6 -based liquid scintillators applying a pulse-height weighting method. The neutron flux was measured with an ionisation chamber placed at 80 cm before the Thorium sample. This chamber has a cathode loaded with two back-to-back layers of about 40 μg/cm 2 10 B. The sample consisted of a metallic natural thorium disc of 8 cm diameter and 0.5 mm thick, corresponding to a thickness of 1.588 10 -3 at/b. The background for the capture measurements consists of a time independent and time dependent component. The former, mainly produced by the radioactive decay of the sample, was deduced from measurements with a closed beam. The latter was measured by replacing the thorium sample with a 0.5 mm thick 208 Pb sample of the same size. Such a Pb sample has practically the same scattering probability as the thorium sample and has a negligible capture yield. Therefore, the 208 Pb run provides a good

Phenomenology of maximal and near-maximal lepton mixing

International Nuclear Information System (INIS)

Gonzalez-Garcia, M. C.; Pena-Garay, Carlos; Nir, Yosef; Smirnov, Alexei Yu.

2001-01-01

The possible existence of maximal or near-maximal lepton mixing constitutes an intriguing challenge for fundamental theories of flavor. We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other (x=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter ε(equivalent to)1-2sin 2 θ ex and quantify the present experimental status for |ε| e mixing comes from solar neutrino experiments. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for 10 -8 eV 2 ∼ 2 ∼ -7 eV 2 . In the mass ranges Δm 2 ∼>1.5x10 -5 eV 2 and 4x10 -10 eV 2 ∼ 2 ∼ -7 eV 2 the full interval |ε| e mixing in atmospheric neutrinos, supernova neutrinos, and neutrinoless double beta decay

Advanced Low Energy Enzyme Catalyzed Solvent for CO₂ Capture

Energy Technology Data Exchange (ETDEWEB)

Zaks, Alex [Akermin Inc., St. Louis, MO (United States); Reardon, John [Akermin Inc., St. Louis, MO (United States)

2013-09-30

A proof-of-concept biocatalyst enhanced solvent process was developed and demonstrated in an integrated bench-scale system using coal post combustion flue gas. The biocatalyst was deployed as a coating on M500X structured packing. Rate enhancement was evaluated using a non-volatile and non-toxic 20 wt% potassium carbonate solution. Greater than 500-fold volumetric scale-up from laboratory to bench scale was demonstrated in this project. Key technical achievements included: 10-fold mass transfer enhancement demonstrated in laboratory testing relative to blank potassium carbonate at 45°C; ~ 7-fold enhancement over blank in bench-scale field testing at National Carbon Capture Center; aerosol emissions were below detection limits (< 0.8 ppm); 90% capture was demonstrated at ~19.5 Nm³/hr (dry basis); and ~ 80% CO₂ capture was demonstrated at ~ 30 Nm³/hr (dry basis) for more than 2800-hrs on flue gas with minimal detectible decline in activity. The regeneration energy requirement was 3.5 GJ/t CO₂ for this solvent, which was below the target of <2.1 GJ/t CO₂. Bench unit testing revealed kinetic limitations in the un-catalyzed stripper at around 85°C, but process modeling based on bench unit data showed that equivalent work of less than 300 kWh/t CO₂ including all CO₂ compression can be achieved at lower temperature stripping conditions. Cost analysis showed that 20% potassium carbonate in a basic solvent flow sheet with biocatalyst coated packing has economic performance comparable to the reference NETL Case-12, 30% MEA. A detailed techno-economic analysis indicated that addition of catalyst in the stripper could reduce the cost of capture by ~6% and cost of avoided CO₂ by ~10% below reference NETL Case-12. Based on these results, a directional plan was identified to reduce the cost of CO₂ capture in future work.

A cosmological problem for maximally symmetric supergravity

International Nuclear Information System (INIS)

German, G.; Ross, G.G.

1986-01-01

Under very general considerations it is shown that inflationary models of the universe based on maximally symmetric supergravity with flat potentials are unable to resolve the cosmological energy density (Polonyi) problem. (orig.)

Low-energy electron collisions with metal clusters: Electron capture and cluster fragmentation

International Nuclear Information System (INIS)

Kresin, V.V.; Scheidemann, A.; Knight, W.D.

1993-01-01

The authors have carried out the first measurement of absolute cross sections for the interaction between electrons and size-resolved free metal clusters. Integral inelastic scattering cross sections have been determined for electron-Na n cluster collisions in the energy range from 0.1 eV to 30 eV. At energies ≤1 eV, cross sections increase with decreasing impact energies, while at higher energies they remain essentially constant. The dominant processes are electron attachment in the low-energy range, and collision-induced fragmentation at higher energies. The magnitude of electron capture cross sections can be quantitatively explained by the effect of the strong polarization field induced in the cluster by the incident electron. The cross sections are very large, reaching values of hundreds of angstrom 2 ; this is due to the highly polarizable nature of metal clusters. The inelastic interaction range for fragmentation collisions is also found to considerably exceed the cluster radius, again reflecting the long-range character of electron-cluster interactions. The important role played by the polarization interaction represents a bridge between the study of collision processes and the extensive research on cluster response properties. Furthermore, insight into the mechanisms of electron scattering is important for understanding production and detection of cluster ions in mass spectrometry and related processes

Optimization of cascade hydropower system operation by genetic algorithm to maximize clean energy output

Directory of Open Access Journals (Sweden)

Aida Tayebiyan

2016-06-01

Full Text Available Background: Several reservoir systems have been constructed for hydropower generation around the world. Hydropower offers an economical source of electricity with reduce carbon emissions. Therefore, it is such a clean and renewable source of energy. Reservoirs that generate hydropower are typically operated with the goal of maximizing energy revenue. Yet, reservoir systems are inefficiently operated and manage according to policies determined at the construction time. It is worth noting that with little enhancement in operation of reservoir system, there could be an increase in efficiency of the scheme for many consumers. Methods: This research develops simulation-optimization models that reflect discrete hedging policy (DHP to manage and operate hydropower reservoir system and analyse it in both single and multireservoir system. Accordingly, three operational models (2 single reservoir systems and 1 multi-reservoir system were constructed and optimized by genetic algorithm (GA. Maximizing the total power generation in horizontal time is chosen as an objective function in order to improve the functional efficiency in hydropower production with consideration to operational and physical limitations. The constructed models, which is a cascade hydropower reservoirs system have been tested and evaluated in the Cameron Highland and Batang Padang in Malaysia. Results: According to the given results, usage of DHP for hydropower reservoir system operation could increase the power generation output to nearly 13% in the studied reservoir system compared to present operating policy (TNB operation. This substantial increase in power production will enhance economic development. Moreover, the given results of single and multi-reservoir systems affirmed that hedging policy could manage the single system much better than operation of the multi-reservoir system. Conclusion: It can be summarized that DHP is an efficient and feasible policy, which could be used

Neutron-capture cross-section measurement for 163Dy In the neutron energy range from 15 to 75 keV

International Nuclear Information System (INIS)

Kim, Hyun Duk; Jung, Eui Jung; Ahn, Jung Keun; Lee, Dae Won; Kim, Guin Yun; Ro, Tae Ik; Min, Young Ki; Igashira, Masayuki; Ohsaki, Toshiro; Mizuno, Satoshi

2002-01-01

The neutron-capture cross-section of 163 Dy were measured in the neutron energy range from 15 to 75 keV at the 3-MV Pelletron accelerator of the Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology. Pulsed neutrons were produced from the 7 Li(p,n) 7 Be reaction by bombarding a metallic lithium target with the 1.903-MeV proton beam. The incident neutron spectra were measured by means of a neutron time-of-flight method with a 6 Li-glass detector. Capture γ-rays were detected with a large anti-Compton NaI(Tl) spectrometer. A pulse-height weighting technique was applied to the capture γ-ray pulse-height spectra to obtain capture yields. The neutron capture cross-section were determined relative to the standard capture cross-sections of 197 Au. The present results were compared with the previous measurements and the evaluated values of ENDF/B-VI

A Novel Dual-Rotor Turbine for Increased Wind Energy Capture

International Nuclear Information System (INIS)

Rosenberg, A; Selvaraj, S; Sharma, A

2014-01-01

Horizontal axis wind turbines suffer from aerodynamic inefficiencies in the blade root region (near the hub) due to several non-aerodynamic constraints. Aerodynamic interactions between turbines in a wind farm also lead to significant loss of wind farm efficiency. A new dual-rotor wind turbine (DRWT) concept is proposed that aims at mitigating these two losses. A DRWT is designed that uses an existing turbine rotor for the main rotor, while the secondary rotor is designed using a high lift-to-drag ratio airfoil. Reynolds Averaged Navier- Stokes computational fluid dynamics simulations are used to optimize the design. Large eddy simulations confirm the increase energy capture potential of the DRWT. Wake comparisons however do not show enhanced entrainment of axial momentum

Neutron capture resonances in 56Fe and 58Fe in the energy range from 10 to 100 keV

International Nuclear Information System (INIS)

Kaeppeler, F.; Wisshak, K.; Hong, L.D.

1982-11-01

The neutron capture cross section of 56 Fe and 58 Fe has been measured in the energy range from 10 to 250 keV relative to the gold standard. A pulsed 3 MV Van de Graaff accelerator and the 7 Li(p, n) reaction served as a neutron source. Capture gamma rays were detected by two C 6 D 6 detectors, which were operated in coincidence and anticoincidence mode. Two-dimensional data acquisition allowed to apply the pulse height weighting technique off-line. The samples were located at a flight path of 60 cm. The total time resolution was 1.2 ns thus allowing for an energy resolution of 2 ns/m. The experimental set-up was optimized with respect to low background and low neutron sensitivity. The additional flight path of 4 cm from the sample to the detector was sufficient to discriminate capture of sample scattered neutrons by the additional time of flight. In this way reliable results were obtained even for the strong s-wave resonances of both isotopes. The experimental capture yield was analyzed with the FANAC code. The energy resolution allowed to extract resonance parameters in the energy range from 10 to 100 keV. The individual systematic uncertainties of the experimental method are discussed in detail. They were found to range between 5 and 10% while the statistical uncertainty is 3-5% for most of the resonances. A comparison to the results of other authors exhibits in case of 56 Fe systematic differences of 7-11%. For 58 Fe the present results differ up to 50% from the only other measurement for this isotope. (orig.) [de

Neutron Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B. W.; Summers, N.; Escher, J.; Firestone, R. B.; Basunia, S.; Hurst, A.; Krticka, M.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H. D.

2011-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

Neutron Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B.W.; Firestone, R.B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

2010-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. this can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. They are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

Maximizing profitability in a hospital outpatient pharmacy.

Science.gov (United States)

Jorgenson, J A; Kilarski, J W; Malatestinic, W N; Rudy, T A

1989-07-01

This paper describes the strategies employed to increase the profitability of an existing ambulatory pharmacy operated by the hospital. Methods to generate new revenue including implementation of a home parenteral therapy program, a home enteral therapy program, a durable medical equipment service, and home care disposable sales are described. Programs to maximize existing revenue sources such as increasing the capture rate on discharge prescriptions, increasing "walk-in" prescription traffic and increasing HMO prescription volumes are discussed. A method utilized to reduce drug expenditures is also presented. By minimizing expenses and increasing the revenues for the ambulatory pharmacy operation, net profit increased from +26,000 to over +140,000 in one year.

The intact capture of hypervelocity dust particles using underdense foams

Science.gov (United States)

Maag, Carl R.; Borg, J.; Tanner, William G.; Stevenson, T. J.; Bibring, J.-P.

1994-01-01

The impact of a hypervelocity projectile (greater than 3 km/s) is a process that subjects both the impactor and the impacted material to a large transient pressure distribution. The resultant stresses cause a large degree of fragmentation, melting, vaporization, and ionization (for normal densities). The pressure regime magnitude, however, is directly related to the density relationship between the projectile and target materials. As a consequence, a high-density impactor on a low-density target will experience the lowest level of damage. Historically, there have been three different approaches toward achieving the lowest possible target density. The first employs a projectile impinging on a foil or film of moderate density, but whose thickness is much less than the particle diameter. This results in the particle experiencing a pressure transient with both a short duration and a greatly reduced destructive effect. A succession of these films, spaced to allow nondestructive energy dissipation between impacts, will reduce the impactor's kinetic energy without allowing its internal energy to rise to the point where destruction of the projectile mass will occur. An added advantage to this method is that it yields the possibility of regions within the captured particle where a minimum of thermal modification has taken place. Polymer foams have been employed as the primary method of capturing particles with minimum degradation. The manufacture of extremely low bulk density materials is usually achieved by the introduction of voids into the material base. It must be noted, however, that a foam structure only has a true bulk density of the mixture at sizes much larger than the cell size, since for impact processes this is of paramount importance. The scale at which the bulk density must still be close to that of the mixture is approximately equal to the impactor. When this density criterion is met, shock pressures during impact are minimized, which in turn maximizes the

Confusion noise from LISA capture sources

International Nuclear Information System (INIS)

Barack, Leor; Cutler, Curt

2004-01-01

Captures of compact objects (COs) by massive black holes (MBHs) in galactic nuclei will be an important source for LISA, the proposed space-based gravitational wave (GW) detector. However, a large fraction of captures will not be individually resolvable - either because they are too distant, have unfavorable orientation, or have too many years to go before final plunge - and so will constitute a source of 'confusion noise', obscuring other types of sources. In this paper we estimate the shape and overall magnitude of the GW background energy spectrum generated by CO captures. This energy spectrum immediately translates to a spectral density S h capt (f) for the amplitude of capture-generated GWs registered by LISA. The overall magnitude of S h capt (f) is linear in the CO capture rates, which are rather uncertain; therefore we present results for a plausible range of rates. S h capt (f) includes the contributions from both resolvable and unresolvable captures, and thus represents an upper limit on the confusion noise level. We then estimate what fraction of S h capt (f) is due to unresolvable sources and hence constitutes confusion noise. We find that almost all of the contribution to S h capt (f) coming from white dwarf and neutron star captures, and at least ∼30% of the contribution from black hole captures, is from sources that cannot be individually resolved. Nevertheless, we show that the impact of capture confusion noise on the total LISA noise curve ranges from insignificant to modest, depending on the rates. Capture rates at the high end of estimated ranges would raise LISA's overall (effective) noise level [fS h eff (f)] 1/2 by at most a factor ∼2 in the frequency range 1-10 mHz, where LISA is most sensitive. While this slightly elevated noise level would somewhat decrease LISA's sensitivity to other classes of sources, we argue that, overall, this would be a pleasant problem for LISA to have: It would also imply that detection rates for CO captures

Capture and retention of tritiated serotonin by the chick notochord

International Nuclear Information System (INIS)

Gerard, Anne; Gerard, Hubert; Dollander, Alexis

1978-01-01

The 3 day old chick notochord capacity to fix tritiated serotonin is maximal in its axis and in cephalic region. Observations permitting to find, the intracellular serotonin binding sites, contribute to an explanation of the capture mechanism and suggest a special direct role of the notochord on the monoaminergic neuron cytodifferentiation [fr

Maximal Bell's inequality violation for non-maximal entanglement

International Nuclear Information System (INIS)

Kobayashi, M.; Khanna, F.; Mann, A.; Revzen, M.; Santana, A.

2004-01-01

Bell's inequality violation (BIQV) for correlations of polarization is studied for a product state of two two-mode squeezed vacuum (TMSV) states. The violation allowed is shown to attain its maximal limit for all values of the squeezing parameter, ζ. We show via an explicit example that a state whose entanglement is not maximal allow maximal BIQV. The Wigner function of the state is non-negative and the average value of either polarization is nil

Energy conservation and maximal entropy production in enzyme reactions.

Science.gov (United States)

Dobovišek, Andrej; Vitas, Marko; Brumen, Milan; Fajmut, Aleš

2017-08-01

A procedure for maximization of the density of entropy production in a single stationary two-step enzyme reaction is developed. Under the constraints of mass conservation, fixed equilibrium constant of a reaction and fixed products of forward and backward enzyme rate constants the existence of maximum in the density of entropy production is demonstrated. In the state with maximal density of entropy production the optimal enzyme rate constants, the stationary concentrations of the substrate and the product, the stationary product yield as well as the stationary reaction flux are calculated. The test, whether these calculated values of the reaction parameters are consistent with their corresponding measured values, is performed for the enzyme Glucose Isomerase. It is found that calculated and measured rate constants agree within an order of magnitude, whereas the calculated reaction flux and the product yield differ from their corresponding measured values for less than 20 % and 5 %, respectively. This indicates that the enzyme Glucose Isomerase, considered in a non-equilibrium stationary state, as found in experiments using the continuous stirred tank reactors, possibly operates close to the state with the maximum in the density of entropy production. Copyright © 2017 Elsevier B.V. All rights reserved.

A current controlled matrix converter for wind energy conversion systems based on permanent magnet synchronous generator

OpenAIRE

Naggar H. Saad; Ahmed A. El-Sattar; Mohamed I. Marei

2016-01-01

The main challenges of wind energy conversion systems (WECS) are to maximize the energy capture from the wind and injecting reactive power during the fault. This paper presents a current controlled matrix converter to interface Permanent Magnet Synchronous Generators (PMSG) based WECS with the grid. To achieve fast dynamic response with reduced current ripples, a hysteresis current control is utilized. The proposed control system decouples the active and reactive components of the PMSG curren...

Capturing energy from ventilation air methane a preliminary design for a new approach

International Nuclear Information System (INIS)

Cluff, D.L.; Kennedy, G.A.; Bennett, J.G.; Foster, P.J.

2015-01-01

Methane is a potent greenhouse gas (GHG), discharged to the atmosphere by coalmining, the natural gas industry and natural biological processes, second only to carbon dioxide; thus, any reduction in atmospheric methane would be globally beneficial. The capture or use of ventilation air methane (VAM) is challenging because it is a high volume low concentration methane source. This results in the routine discharge of methane into the atmosphere. A review of VAM mitigation technologies is provided and the main disadvantages of the existing technologies are discussed. In the proposed VamTurBurner © system, the heat from the combustion chamber is transferred to the preheating zone either by a heat exchanger or by redirecting the combustion products to mix with the ventilation air stream from a coalmine. Gas turbines (GT) are used to produce electricity with the exhaust gases directed to mix with the incoming ventilation airflow. The turbulence introduced by the GT exhaust assists with mixing of the incoming ventilation airflow and the return flow of combustion products from the combustion chamber. The combustion products are a source of heat, which increases the temperature of the incoming ventilation air to a value high enough for the methane to undergo flameless combustion upon encountering the igniters. The high temperature combustion products enter a multi-generation system. The multi-generation system is based on mature engineering technology such as heat exchangers and steam turbines. The residual heat provides additional heat based products such as industrial scale drying, chilling by an absorption chiller or simply hot water. The VamTurBurner © uses the energy from the GT, igniters and VAM to provide clean efficient energy while mitigating the atmospheric emissions of methane. The opportunity to collect carbon credits may improve the economics. Since the VAM is a free energy source, the output of the system is greater than the purchased energy. - Highlights: �

An Improved Optimization Function for Maximizing User Comfort with Minimum Energy Consumption in Smart Homes

Directory of Open Access Journals (Sweden)

Israr Ullah

2017-11-01

Full Text Available In the smart home environment, efficient energy management is a challenging task. Solutions are needed to achieve a high occupant comfort level with minimum energy consumption. User comfort is measured in terms of three fundamental parameters: (a thermal comfort, (b visual comfort and (c air quality. Temperature, illumination and CO 2 sensors are used to collect indoor contextual information. In this paper, we have proposed an improved optimization function to achieve maximum user comfort in the building environment with minimum energy consumption. A comprehensive formulation is done for energy optimization with detailed analysis. The Kalman filter algorithm is used to remove noise in sensor readings by predicting actual parameter values. For optimization, we have used genetic algorithm (GA and particle swarm optimization (PSO algorithms and performed comparative analysis with a baseline scheme on real data collected for a one-month duration in our lab’s indoor environment. Experimental results show that the proposed optimization function has achieved a 27 . 32 % and a 31 . 42 % reduction in energy consumption with PSO and GA, respectively. The user comfort index was also improved by 10 % i.e., from 0 . 86 to 0 . 96 . GA-based optimization results were better than PSO, as it has achieved almost the same user comfort with 4 . 19 % reduced energy consumption. Results show that the proposed optimization function gives better results than the baseline scheme in terms of user comfort and the amount of consumed energy. The proposed system can help with collecting the data about user preferences and energy consumption for long-term analysis and better decision making in the future for efficient resource utilization and overall profit maximization.

Maximizing and customer loyalty: Are maximizers less loyal?

Directory of Open Access Journals (Sweden)

Linda Lai

2011-06-01

Full Text Available Despite their efforts to choose the best of all available solutions, maximizers seem to be more inclined than satisficers to regret their choices and to experience post-decisional dissonance. Maximizers may therefore be expected to change their decisions more frequently and hence exhibit lower customer loyalty to providers of products and services compared to satisficers. Findings from the study reported here (N = 1978 support this prediction. Maximizers reported significantly higher intentions to switch to another service provider (television provider than satisficers. Maximizers' intentions to switch appear to be intensified and mediated by higher proneness to regret, increased desire to discuss relevant choices with others, higher levels of perceived knowledge of alternatives, and higher ego involvement in the end product, compared to satisficers. Opportunities for future research are suggested.

Beam neutron energy optimization for boron neutron capture therapy using monte Carlo method

International Nuclear Information System (INIS)

Pazirandeh, A.; Shekarian, E.

2006-01-01

In last two decades the optimal neutron energy for the treatment of deep seated tumors in boron neutron capture therapy in view of neutron physics and chemical compounds of boron carrier has been under thorough study. Although neutron absorption cross section of boron is high (3836b), the treatment of deep seated tumors such as glioblastoma multiform requires beam of neutrons of higher energy that can penetrate deeply into the brain and thermalized in the proximity of the tumor. Dosage from recoil proton associated with fast neutrons however poses some constraints on maximum neutron energy that can be used in the treatment. For this reason neutrons in the epithermal energy range of 10eV-10keV are generally to be the most appropriate. The simulation carried out by Monte Carlo methods using MCBNCT and MCNP4C codes along with the cross section library in 290 groups extracted from ENDF/B6 main library. The ptimal neutron energy for deep seated tumors depends on the sue and depth of tumor. Our estimated optimized energy for the tumor of 5cm wide and 1-2cm thick stands at 5cm depth is in the range of 3-5keV

On the configuration of supercapacitors for maximizing electrochemical performance.

Science.gov (United States)

Zhang, Jintao; Zhao, X S

2012-05-01

Supercapacitors, which are attracting rapidly growing interest from both academia and industry, are important energy-storage devices for acquiring sustainable energy. Recent years have seen a number of significant breakthroughs in the research and development of supercapacitors. The emergence of innovative electrode materials (e.g., graphene) has clearly provided great opportunities for advancing the science in the field of electrochemical energy storage. Conversely, smart configurations of electrode materials and new designs of supercapacitor devices have, in many cases, boosted the electrochemical performance of the materials. We attempt to summarize recent research progress towards the design and configuration of electrode materials to maximize supercapacitor performance in terms of energy density, power density, and cycle stability. With a brief description of the structure, energy-storage mechanism, and electrode configuration of supercapacitor devices, the design and configuration of symmetric supercapacitors are discussed, followed by that of asymmetric and hybrid supercapacitors. Emphasis is placed on the rational design and configuration of supercapacitor electrodes to maximize the electrochemical performance of the device. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Quantitative Three-Dimensional Image Analysis Tool for Maximal Acquisition of Spatial Heterogeneity Data.

Science.gov (United States)

Allenby, Mark C; Misener, Ruth; Panoskaltsis, Nicki; Mantalaris, Athanasios

2017-02-01

Three-dimensional (3D) imaging techniques provide spatial insight into environmental and cellular interactions and are implemented in various fields, including tissue engineering, but have been restricted by limited quantification tools that misrepresent or underutilize the cellular phenomena captured. This study develops image postprocessing algorithms pairing complex Euclidean metrics with Monte Carlo simulations to quantitatively assess cell and microenvironment spatial distributions while utilizing, for the first time, the entire 3D image captured. Although current methods only analyze a central fraction of presented confocal microscopy images, the proposed algorithms can utilize 210% more cells to calculate 3D spatial distributions that can span a 23-fold longer distance. These algorithms seek to leverage the high sample cost of 3D tissue imaging techniques by extracting maximal quantitative data throughout the captured image.

Carbon capture by hybrid separation processes

NARCIS (Netherlands)

van Benthum, R.J.; van Kemenade, H.P.; Brouwers, J.J.H.

2014-01-01

Even though there is an increasing development of carbon capture technology over the last decade, large-scale implementation is still far from common practice, mainly caused by the energy intensiveness of carbon capture processes and the lack of regulation. In absence of strict regulation, less

Muscle trade-offs in a power-amplified prey capture system.

Science.gov (United States)

Blanco, M Mendoza; Patek, S N

2014-05-01

Should animals operating at great speeds and accelerations use fast or slow muscles? The answer hinges on a fundamental trade-off: muscles can be maximally fast or forceful, but not both. Direct lever systems offer a straightforward manifestation of this trade-off, yet the fastest organisms use power amplification, not direct lever action. Power-amplified systems typically use slow, forceful muscles to preload springs, which then rapidly release elastic potential energy to generate high speeds and accelerations. However, a fast response to a stimulus may necessitate fast spring-loading. Across 22 mantis shrimp species (Stomatopoda), this study examined how muscle anatomy correlates with spring mechanics and appendage type. We found that muscle force is maximized through physiological cross-sectional area, but not through sarcomere length. Sit-and-wait predators (spearers) had the shortest sarcomere lengths (fastest contractions) and the slowest strike speeds. The species that crush shells (smashers) had the fastest speeds, most forceful springs, and longest sarcomeres. The origin of the smasher clade yielded dazzlingly high accelerations, perhaps due to the release from fast spring-loading for evasive prey capture. This study offers a new window into the dynamics of force-speed trade-offs in muscles in the biomechanical, comparative evolutionary framework of power-amplified systems. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Measurement of keV-neutron capture cross sections and capture gamma-ray spectra of Er isotopes

International Nuclear Information System (INIS)

Harun-Ar-Rashid, A.K.M.; Igashira, Masayuki; Ohsaki, Toshiro

2000-01-01

Neutron capture cross sections and capture γ-ray spectra of 166,167, 168 Er were measured in the energy region of 10 to 550 keV. The measurements were performed with a pulsed 7 Li(p,n) 7 Be neutron source and a large anti-Compton NaI(Tl) γ-ray spectrometer. A pulse-height weighting technique and the standard capture cross sections of gold were used to derive the capture cross sections. The errors of the derived cross sections were about 5%. The present results were compared with other measurements and evaluations. The observed capture γ-ray pulse-height spectra were unfolded to obtain the corresponding γ-ray spectra. An anomalous shoulder was observed around 3 MeV in each of the capture γ-ray spectra. (author)

Maximal Rashba-like spin splitting via kinetic-energy-coupled inversion-symmetry breaking

Science.gov (United States)

Sunko, Veronika; Rosner, H.; Kushwaha, P.; Khim, S.; Mazzola, F.; Bawden, L.; Clark, O. J.; Riley, J. M.; Kasinathan, D.; Haverkort, M. W.; Kim, T. K.; Hoesch, M.; Fujii, J.; Vobornik, I.; MacKenzie, A. P.; King, P. D. C.

2017-09-01

Engineering and enhancing the breaking of inversion symmetry in solids—that is, allowing electrons to differentiate between ‘up’ and ‘down’—is a key goal in condensed-matter physics and materials science because it can be used to stabilize states that are of fundamental interest and also have potential practical applications. Examples include improved ferroelectrics for memory devices and materials that host Majorana zero modes for quantum computing. Although inversion symmetry is naturally broken in several crystalline environments, such as at surfaces and interfaces, maximizing the influence of this effect on the electronic states of interest remains a challenge. Here we present a mechanism for realizing a much larger coupling of inversion-symmetry breaking to itinerant surface electrons than is typically achieved. The key element is a pronounced asymmetry of surface hopping energies—that is, a kinetic-energy-coupled inversion-symmetry breaking, the energy scale of which is a substantial fraction of the bandwidth. Using spin- and angle-resolved photoemission spectroscopy, we demonstrate that such a strong inversion-symmetry breaking, when combined with spin-orbit interactions, can mediate Rashba-like spin splittings that are much larger than would typically be expected. The energy scale of the inversion-symmetry breaking that we achieve is so large that the spin splitting in the CoO2- and RhO2-derived surface states of delafossite oxides becomes controlled by the full atomic spin-orbit coupling of the 3d and 4d transition metals, resulting in some of the largest known Rashba-like spin splittings. The core structural building blocks that facilitate the bandwidth-scaled inversion-symmetry breaking are common to numerous materials. Our findings therefore provide opportunities for creating spin-textured states and suggest routes to interfacial control of inversion-symmetry breaking in designer heterostructures of oxides and other material classes.

Comparison between the mechanical and radiative electron-capture processes at high energies

International Nuclear Information System (INIS)

Gonzalez, A.D.; Miraglia, J.E.

1984-01-01

The ground-state--ground-state mechanical and radiative electron-capture processes are studied at very high, but not relativistic, projectile velocities. Three-body calculations were carried out with use of the continuum distorted-wave theoretical method for both processes. Total cross sections and final-atom angular distributions were computed, and the importance of each mechanism examined. For total cross sections, the numerical results reaffirm that the radiative process is the predominant mechanism at very high projectile energies. For a given incident charge, the range of projectile energies in which the nonrelativistic radiative mechanism is the most important decreases as the target charge increases. It is found that the radiative mechanism produces a very sharp final-atom angular distribution in the forward direction. When both processes, the radiative and mechanical, give the same total cross section, the calculations show that the radiative differential cross section in the forward direction is almost 2 orders of magnitude larger than the mechanical one

Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B.W.; Firestone, Richard B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

2010-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF has been used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy an is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We use CASINO, a version of DICEBOX that is modified for this purpose. This can be used to simulate the neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modelling of unknown assemblies.

BioCO2 - a multidisciplinary, biological approach using solar energy to capture CO2 while producing H2 and high value products.

Science.gov (United States)

Skjånes, Kari; Lindblad, Peter; Muller, Jiri

2007-10-01

Many areas of algae technology have developed over the last decades, and there is an established market for products derived from algae, dominated by health food and aquaculture. In addition, the interest for active biomolecules from algae is increasing rapidly. The need for CO(2) management, in particular capture and storage is currently an important technological, economical and global political issue and will continue to be so until alternative energy sources and energy carriers diminish the need for fossil fuels. This review summarizes in an integrated manner different technologies for use of algae, demonstrating the possibility of combining different areas of algae technology to capture CO(2) and using the obtained algal biomass for various industrial applications thus bringing added value to the capturing and storage processes. Furthermore, we emphasize the use of algae in a novel biological process which produces H(2) directly from solar energy in contrast to the conventional CO(2) neutral biological methods. This biological process is a part of the proposed integrated CO(2) management scheme.

An Efficient Approach to Mining Maximal Contiguous Frequent Patterns from Large DNA Sequence Databases

Directory of Open Access Journals (Sweden)

Md. Rezaul Karim

2012-03-01

Full Text Available Mining interesting patterns from DNA sequences is one of the most challenging tasks in bioinformatics and computational biology. Maximal contiguous frequent patterns are preferable for expressing the function and structure of DNA sequences and hence can capture the common data characteristics among related sequences. Biologists are interested in finding frequent orderly arrangements of motifs that are responsible for similar expression of a group of genes. In order to reduce mining time and complexity, however, most existing sequence mining algorithms either focus on finding short DNA sequences or require explicit specification of sequence lengths in advance. The challenge is to find longer sequences without specifying sequence lengths in advance. In this paper, we propose an efficient approach to mining maximal contiguous frequent patterns from large DNA sequence datasets. The experimental results show that our proposed approach is memory-efficient and mines maximal contiguous frequent patterns within a reasonable time.

Principles of maximally classical and maximally realistic quantum ...

Indian Academy of Sciences (India)

Principles of maximally classical and maximally realistic quantum mechanics. S M ROY. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India. Abstract. Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2N-dimensional phase space, ...

The "1"2C("1"6O,γ"2"8Si) radiative capture reaction at sub-barrier energies

International Nuclear Information System (INIS)

Goasduff, A.; Courtin, S.; Haas, F.; Lebhertz, D.; Jenkins, D.G.; Fallis, J.; Ruiz, C.; Hutcheon, D.A.; Amandruz, P.A.; Davis, C.; Hager, U.; Ottewell, D.; Ruprecht, G.

2014-01-01

The heavy-ion radiative capture "1"2C("1"6O,γ"2"8Si) was measured at the sub-Coulomb barrier bombarding energy E(lab) = 15.7 MeV, which corresponds to the lowest important resonance observed in the "1"2C + "1"6O fusion excitation function. Thanks to combination of the bismuth germanate (BGO) γ-ray array and the 0 degree DRAGON electromagnetic spectrometer at TRIUMF, the γ-decay spectrum from the entrance channel down to the ground state of "2"8Si was measured. Comparisons of the experimental spectrum to γ spectrum extracted from Monte-Carlo simulations of the complete setup suggest a J"π = 2"+ spin-parity assignment to the entrance channel and yield the radiative capture cross section σ(RC) = 0.22 ± 0.04 μb. Combining this present spin assignment with previous data on radiative capture, a J (J + 1) systematics was constructed, and it indicated a moment of inertia commensurate with the "1"2C+"1"6O grazing angular momentum. Strong dipole transitions are observed from the entrance channel to T = 1 states around 11.5 MeV and are found to result from enhanced M1_I_V transitions to states exhausting a large part of the M1 sum rule built on the ground state of "2"8Si. This specific decay was also reported at bombarding energies close to the Coulomb barrier in our previous study of the "1"2C("1"2C,γ"2"4Mg) heavy-ion radiative capture reaction. Similarities between both systems are investigated. (authors)

Study on keV-neutron capture cross sections and capture γ-ray spectra of 117,119Sn

International Nuclear Information System (INIS)

Nishiyama, J.; Igashira, M.; Ohsaki, T.; Kim, G.N.; Chung, W.C.; Ro, T.I.

2006-01-01

The capture cross sections and capture γ-ray spectra of 117,119 Sn were measured in an incident neutron energy region from 10 to 100 keV and at 570 keV, using a 1.5-ns pulsed neutron source by the 7 Li(p,n) 7 Be reaction and a large anti-Compton NaI(Tl) γ-ray spectrometer. A pulse-height weighting technique was applied to observed capture γ-ray pulse-height spectra to derive capture yields. The capture cross sections of 117,119 Sn were obtained with the error of about 5% by using the standard capture cross sections of 197 Au. The present cross sections were compared with previous experimental data and the evaluated values in JENDL-3.3 and ENDF/B-VI. The capture γ-ray spectra of 117,119 Sn were derived by unfolding the observed capture γ-ray pulse-height spectra. The calculations of capture cross sections and capture γ-ray spectra of 117,119 Sn were performed with the EMPIRE-II code. The calculated results were compared with the present experimental ones. (author)

Electron capture in low- and intermediate-energy collisions between completely stripped light ions and metastable H(2s) targets

International Nuclear Information System (INIS)

Blanco, S.A.; Falcon, C.A.; Reinhold, C.O.; Casaubon, J.I.; Piacentini, R.D.

1987-01-01

Total cross sections for electron capture from H(2s) targets by He 2+ ions have been computed in the impact velocity range 0.05-0.5 au. Calculations were performed using a molecular close-coupling approach with inclusion of electron translation factors. A ten-state molecular basis set was considered. A comparison is made with Landau-Zener results for the same system. Intermediate projectile energy classical Monte Carlo capture cross sections are also presented for H + , He 2+ , Li 3+ and C 6+ projectiles. (author)

Robust Weighted Sum Harvested Energy Maximization for SWIPT Cognitive Radio Networks Based on Particle Swarm Optimization.

Science.gov (United States)

Tuan, Pham Viet; Koo, Insoo

2017-10-06

In this paper, we consider multiuser simultaneous wireless information and power transfer (SWIPT) for cognitive radio systems where a secondary transmitter (ST) with an antenna array provides information and energy to multiple single-antenna secondary receivers (SRs) equipped with a power splitting (PS) receiving scheme when multiple primary users (PUs) exist. The main objective of the paper is to maximize weighted sum harvested energy for SRs while satisfying their minimum required signal-to-interference-plus-noise ratio (SINR), the limited transmission power at the ST, and the interference threshold of each PU. For the perfect channel state information (CSI), the optimal beamforming vectors and PS ratios are achieved by the proposed PSO-SDR in which semidefinite relaxation (SDR) and particle swarm optimization (PSO) methods are jointly combined. We prove that SDR always has a rank-1 solution, and is indeed tight. For the imperfect CSI with bounded channel vector errors, the upper bound of weighted sum harvested energy (WSHE) is also obtained through the S-Procedure. Finally, simulation results demonstrate that the proposed PSO-SDR has fast convergence and better performance as compared to the other baseline schemes.

Profit maximization mitigates competition

DEFF Research Database (Denmark)

Dierker, Egbert; Grodal, Birgit

1996-01-01

We consider oligopolistic markets in which the notion of shareholders' utility is well-defined and compare the Bertrand-Nash equilibria in case of utility maximization with those under the usual profit maximization hypothesis. Our main result states that profit maximization leads to less price...... competition than utility maximization. Since profit maximization tends to raise prices, it may be regarded as beneficial for the owners as a whole. Moreover, if profit maximization is a good proxy for utility maximization, then there is no need for a general equilibrium analysis that takes the distribution...... of profits among consumers fully into account and partial equilibrium analysis suffices...

Implications of maximal Jarlskog invariant and maximal CP violation

International Nuclear Information System (INIS)

Rodriguez-Jauregui, E.; Universidad Nacional Autonoma de Mexico

2001-04-01

We argue here why CP violating phase Φ in the quark mixing matrix is maximal, that is, Φ=90 . In the Standard Model CP violation is related to the Jarlskog invariant J, which can be obtained from non commuting Hermitian mass matrices. In this article we derive the conditions to have Hermitian mass matrices which give maximal Jarlskog invariant J and maximal CP violating phase Φ. We find that all squared moduli of the quark mixing elements have a singular point when the CP violation phase Φ takes the value Φ=90 . This special feature of the Jarlskog invariant J and the quark mixing matrix is a clear and precise indication that CP violating Phase Φ is maximal in order to let nature treat democratically all of the quark mixing matrix moduli. (orig.)

Alignment in double capture processes

International Nuclear Information System (INIS)

Moretto-Capelle, P.; Benhenni, M.; Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A.

1993-01-01

The electron spectra emitted when a double capture occurs in N 7+ +He and Ne 8+ +He systems at 10 qkeV collisional energy, allow us to determine the angular distributions of the 3 ell 3 ell ' lines through a special spectra fitting procedure which includes interferences between neighbouring states. It is found that the doubly excited states populated in double capture processes are generally aligned

Long-term energy and climate implications of carbon capture and storage deployment strategies in the US coal-fired electricity fleet.

Science.gov (United States)

Sathre, Roger; Masanet, Eric

2012-09-04

To understand the long-term energy and climate implications of different implementation strategies for carbon capture and storage (CCS) in the US coal-fired electricity fleet, we integrate three analytical elements: scenario projection of energy supply systems, temporally explicit life cycle modeling, and time-dependent calculation of radiative forcing. Assuming continued large-scale use of coal for electricity generation, we find that aggressive implementation of CCS could reduce cumulative greenhouse gas emissions (CO(2), CH(4), and N(2)O) from the US coal-fired power fleet through 2100 by 37-58%. Cumulative radiative forcing through 2100 would be reduced by only 24-46%, due to the front-loaded time profile of the emissions and the long atmospheric residence time of CO(2). The efficiency of energy conversion and carbon capture technologies strongly affects the amount of primary energy used but has little effect on greenhouse gas emissions or radiative forcing. Delaying implementation of CCS deployment significantly increases long-term radiative forcing. This study highlights the time-dynamic nature of potential climate benefits and energy costs of different CCS deployment pathways and identifies opportunities and constraints of successful CCS implementation.

An international partnership approach to clean energy technology innovation: Carbon capture and storage

Science.gov (United States)

Yang, Xiaoliang

Is a global research partnership effective in developing, deploying, and diffusing clean energy technologies? Drawing on and extending innovation system studies, this doctoral dissertation elaborates an analytical model for a global technology learning system; examines the rationales, mechanisms, and effectiveness of the United States-- China Clean Energy Research Center Advanced Coal Technology Consortium (CERC-ACTC); and analyzes government's role in developing and implementing carbon capture and storage technologies in the United States (U.S.) and China. Studies have shown that successful technology innovation leads to economic prosperity and national competence, and prove that technology innovation does not happen in isolation but rather within interactive systems among stakeholders. However, the innovation process itself remains unclear, particularly with regard to interactive learning among and between major institutional actors, including technology developers, regulators, and financial organizations. This study seeks to advance scholarship on the interactive learning from the angle of global interactive learning. This dissertation research project seeks, as well, to inform policy-makers of how to strengthen international collaboration in clean energy technology development. The U.S.--China CERC-ACTC announced by Presidents Obama and Hu in 2009, provided a unique opportunity to close this scholarly gap. ACTC aimed to "advance the coal technology needed to safely, effectively, and efficiently utilize coal resources including the ability to capture, store, and utilize the emissions from coal use in both nations " through the joint research and development by U.S. and Chinese scientists and engineers. This dissertation project included one-year field research in the two countries, with in-depth interviews of key stakeholders, a survey of Consortium participants, analysis of available data, and site visits to collaborative research projects from 2013-2014. This

Single-electron capture for 2-8 keV incident energy and direct scattering at 6 keV in He2+-He collisions

International Nuclear Information System (INIS)

Bordenave-Montesquieu, D.; Dagnac, R.

1992-01-01

We studied the single-electron capture as well as the direct processes occurring when a He 2+ ion is scattered by a He target. Doubly differential cross sections were measured for single-electron capture with a collision energy ranging from 2 to 8 keV and a scattering angle varying from 10' to 3 o 30' (laboratory frame). Single-electron capture into excited states of He + was found to be the dominant process, confirming a previous experimental study. Elastic scattering and ionization differential cross sections were measured for E = 6 keV. (Author)

Profit maximization algorithms for utility companies in an oligopolistic energy market with dynamic prices and intelligent users

Directory of Open Access Journals (Sweden)

Tiansong Cui

2016-01-01

Full Text Available Dynamic energy pricing provides a promising solution for the utility companies to incentivize energy users to perform demand side management in order to minimize their electric bills. Moreover, the emerging decentralized smart grid, which is a likely infrastructure scenario for future electrical power networks, allows energy consumers to select their energy provider from among multiple utility companies in any billing period. This paper thus starts by considering an oligopolistic energy market with multiple non-cooperative (competitive utility companies, and addresses the problem of determining dynamic energy prices for every utility company in this market based on a modified Bertrand Competition Model of user behaviors. Two methods of dynamic energy pricing are proposed for a utility company to maximize its total profit. The first method finds the greatest lower bound on the total profit that can be achieved by the utility company, whereas the second method finds the best response of a utility company to dynamic pricing policies that the other companies have adopted in previous billing periods. To exploit the advantages of each method while compensating their shortcomings, an adaptive dynamic pricing policy is proposed based on a machine learning technique, which finds a good balance between invocations of the two aforesaid methods. Experimental results show that the adaptive policy results in consistently high profit for the utility company no matter what policies are employed by the other companies.

Optimal quantum error correcting codes from absolutely maximally entangled states

Science.gov (United States)

Raissi, Zahra; Gogolin, Christian; Riera, Arnau; Acín, Antonio

2018-02-01

Absolutely maximally entangled (AME) states are pure multi-partite generalizations of the bipartite maximally entangled states with the property that all reduced states of at most half the system size are in the maximally mixed state. AME states are of interest for multipartite teleportation and quantum secret sharing and have recently found new applications in the context of high-energy physics in toy models realizing the AdS/CFT-correspondence. We work out in detail the connection between AME states of minimal support and classical maximum distance separable (MDS) error correcting codes and, in particular, provide explicit closed form expressions for AME states of n parties with local dimension \

Trade-offs between energy maximization and parental care in a central place forager, the sea otter

Science.gov (United States)

Thometz, N M; Staedler, M.M.; Tomoleoni, Joseph; Bodkin, James L.; Bentall, G.B.; Tinker, M. Tim

2016-01-01

Between 1999 and 2014, 126 archival time–depth recorders (TDRs) were used to examine the foraging behavior of southern sea otters (Enhydra lutris nereis) off the coast of California, in both resource-abundant (recently occupied, low sea otter density) and resource-limited (long-occupied, high sea otter density) locations. Following predictions of foraging theory, sea otters generally behaved as energy rate maximizers. Males and females without pups employed similar foraging strategies to optimize rates of energy intake in resource-limited habitats, with some exceptions. Both groups increased overall foraging effort and made deeper, longer and more energetically costly dives as resources became limited, but males were more likely than females without pups to utilize extreme dive profiles. In contrast, females caring for young pups (≤10 weeks) prioritized parental care over energy optimization. The relative importance of parental care versus energy optimization for adult females with pups appeared to reflect developmental changes as dependent young matured. Indeed, contrary to females during the initial stages of lactation, females with large pups approaching weaning once again prioritized optimizing energy intake. The increasing prioritization of energy optimization over the course of lactation was possible due to the physiological development of pups and likely driven by the energetic deficit incurred by females early in lactation. Our results suggest that regardless of resource availability, females at the end of lactation approach a species-specific ceiling for percent time foraging and that reproductive females in the central portion of the current southern sea otter range are disproportionately affected by resource limitation.

Maximizers versus satisficers

Directory of Open Access Journals (Sweden)

Andrew M. Parker

2007-12-01

Full Text Available Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007. Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002, we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions, more avoidance of decision making, and greater tendency to experience regret. Contrary to predictions, self-reported maximizers were more likely to report spontaneous decision making. However, the relationship between self-reported maximizing and worse life outcomes is largely unaffected by controls for measures of other decision-making styles, decision-making competence, and demographic variables.

Energy, complexity and wealth maximization

CERN Document Server

Ayres, Robert

2016-01-01

This book is about the mechanisms of wealth creation, or what we like to think of as evolutionary “progress”. For the modern economy, natural wealth consists of complex physical structures of condensed (“frozen”) energy – mass - maintained in the earth’s crust far from thermodynamic equilibrium. However, we usually perceive wealth as created when mutation or “invention” – a change agent - introduces something different, and fitter, and usually after some part of the natural wealth of the planet has been exploited in an episode of “creative destruction”. Selection out of the resulting diversity is determined by survival in a competitive environment, whether a planet, a habitat, or a market. While human wealth is associated with money and what it can buy, it is ultimately based on natural wealth, both as materials transformed into useful artifacts, and how those artifacts, activated by energy, can create and transmit useful information. Humans have learned how to transform natural wealth i...

P-d capture reactions in muonic molecules

International Nuclear Information System (INIS)

Friar, J.L.

1991-01-01

Capture reactions for very low-energy n-d and p-d systems are calculated and compared with experiment, as are low-energy n-d and p-d scattering. We find excellent agreement for the n-d scattering lengths, but poor agreement for the p-d case, which we believe is a problem with the experimental extrapolation. The n-d radiative capture is sensitive to details of the meson-exchange currents, but reasonable models agree with the data. The latter models are in good agreement with experiment when extended to the p-d case. Our large quartet capture rate resolves a long-standing anomaly. The EO capture matrix element recently obtained from a reanalysis of internal conversion in muonic molecules is in excellent agreement with our predictions. This matrix element is very clean theoretically and provides the best test of the calculations. 33 refs., 3 figs., 1 tab

Performance Analysis of Cold Energy Recovery from CO2 Injection in Ship-Based Carbon Capture and Storage (CCS

Directory of Open Access Journals (Sweden)

Hwalong You

2014-11-01

Full Text Available Carbon capture and storage (CCS technology is one of the practical solutions for mitigating the effects of global warming. When captured CO2 is injected into storage sites, the CO2 is subjected to a heating process. In a conventional CO2 injection system, CO2 cold energy is wasted during this heating process. This study proposes a new CO2 injection system that takes advantage of the cold energy using the Rankine cycle. The study compared the conventional system with the new CO2 injection system in terms of specific net power consumption, exergy efficiency, and life-cycle cost (LCC to estimate the economic effects. The results showed that the new system reduced specific net power consumption and yielded higher exergy efficiency. The LCC of the new system was more economical. Several cases were examined corresponding to different conditions, specifically, discharge pressure and seawater temperature. This information may affect decision-making when CCS projects are implemented.

Alignment in double capture processes

Energy Technology Data Exchange (ETDEWEB)

Moretto-Capelle, P.; Benhenni, M.; Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A. (IRSAMC, URA CNRS 770, Univ. Paul Sabatier, 118 rte de Narbonne, 31062 Toulouse Cedex (France))

1993-06-05

The electron spectra emitted when a double capture occurs in N[sup 7+]+He and Ne[sup 8+]+He systems at 10 qkeV collisional energy, allow us to determine the angular distributions of the 3[ell]3[ell] [prime] lines through a special spectra fitting procedure which includes interferences between neighbouring states. It is found that the doubly excited states populated in double capture processes are generally aligned.

Carbon Capture: A Technology Assessment

Science.gov (United States)

2013-10-21

whereas laboratory-scale experiments typically seek to validate or obtain data for specific components of a system. Laboratory- and bench-scale processes...Plant,” Energy, vol. 35 (2010), pp. 841-850. E. Favre, R. Bounaceur, and D. Roizard, “ Biogas , Membranes and Carbon Dioxide Capture,” Journal of...pp. 1-49. 64 Favre, “ Biogas , Membranes.” Carbon Capture: A Technology Assessment Congressional Research Service 42 materials have pore sizes

Opportunistic Energy-Aware Amplify-and-Forward Cooperative Systems with Imperfect CSI

KAUST Repository

Amin, Osama

2015-07-29

Recently, much attention has been paid to the green design of wireless communication systems using energy efficiency (EE) metrics that should capture all energy consumption sources to deliver the required data. In this paper, we design an energyefficient relay assisted communication system based on estimated channel state information (CSI). It employs amplify-andforward relaying and switches between different communication schemes, which are known as direct-transmission, two-hop and cooperative-transmission schemes, using the estimated CSI in order to maximize the EE. Two estimation strategies are assumed, namely disintegrated channel estimation and cascaded channel estimation. To formulate an accurate EE metric for the proposed opportunistic amplify-and-forward system, the channel estimation cost is reflected on the EE metric by including its impact in the signal-to-noise ratio term and in the energy consumption during the channels estimation phase. Based on the formulated EE metric, we propose an adaptive power allocation algorithm to maximize the EE of the proposed opportunistic amplify-andforward system with channel estimation. Furthermore, we study the impact of the estimation parameters on the proposed system via simulation examples.

Coherent Wave Measurement Buoy Arrays to Support Wave Energy Extraction

Science.gov (United States)

Spada, F.; Chang, G.; Jones, C.; Janssen, T. T.; Barney, P.; Roberts, J.

2016-02-01

Wave energy is the most abundant form of hydrokinetic energy in the United States and wave energy converters (WECs) are being developed to extract the maximum possible power from the prevailing wave climate. However, maximum wave energy capture is currently limited by the narrow banded frequency response of WECs as well as extended protective shutdown requirements during periods of large waves. These limitations must be overcome in order to maximize energy extraction, thus significantly decreasing the cost of wave energy and making it a viable energy source. Techno-economic studies of several WEC devices have shown significant potential to improve wave energy capture efficiency through operational control strategies that incorporate real-time information about local surface wave motions. Integral Consulting Inc., with ARPA-E support, is partnering with Sandia National Laboratories and Spoondrift LLC to develop a coherent array of wave-measuring devices to relay and enable the prediction of wave-resolved surface dynamics at a WEC location ahead of real time. This capability will provide necessary information to optimize power production of WECs through control strategies, thereby allowing for a single WEC design to perform more effectively across a wide range of wave environments. The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000514.

Carbon capture and storage: Fundamental thermodynamics and current technology

International Nuclear Information System (INIS)

Page, S.C.; Williamson, A.G.; Mason, I.G.

2009-01-01

Carbon capture and storage (CCS) is considered a leading technology for reducing CO 2 emissions from fossil-fuelled electricity generation plants and could permit the continued use of coal and gas whilst meeting greenhouse gas targets. However considerable energy is required for the capture, compression, transport and storage steps involved. In this paper, energy penalty information in the literature is reviewed, and thermodynamically ideal and 'real world' energy penalty values are calculated. For a sub-critical pulverized coal (PC) plant, the energy penalty values for 100% capture are 48.6% and 43.5% for liquefied CO 2 , and for CO 2 compressed to 11 MPa, respectively. When assumptions for supercritical plants were incorporated, results were in broad agreement with published values arising from process modelling. However, we show that energy use in existing capture operations is considerably greater than indicated by most projections. Full CCS demonstration plants are now required to verify modelled energy penalty values. However, it appears unlikely that CCS will deliver significant CO 2 reductions in a timely fashion. In addition, many uncertainties remain over the permanence of CO 2 storage, either in geological formations, or beneath the ocean. We conclude that further investment in CCS should be seriously questioned by policy makers.

Ultralow Parasitic Energy for Postcombustion CO ₂ Capture Realized in a Nickel Isonicotinate Metal–Organic Framework with Excellent Moisture Stability

Energy Technology Data Exchange (ETDEWEB)

Nandi, Shyamapada; Collins, Sean [Centre; amp, Department of Chemistry; Chakraborty, Debanjan; Banerjee, Debasis [Physical; Thallapally, Praveen K. [Physical; Woo, Tom K. [Centre; amp, Department of Chemistry; Vaidhyanathan, Ramanathan

2017-01-25

Metal-organic frameworks (MOFs) have attracted significant attention as solid sorbents in gas separation processes for low-energy postcombustion CO₂ capture. The parasitic energy (PE) has been put forward as a holistic parameter that measures how energy efficient (and therefore cost-effective) the CO₂ capture process will be using the material. In this work, we present a nickel isonicotinate based ultramicroporous MOF, 1 [Ni-(4PyC)(2)center dot DMF], that has the lowest PE for postcombustion CO, capture reported to date. We calculate a PE of 655 kJ/kg CO₂, which is lower than that of the best performing material previously reported, Mg-MOF-74. Further, 1 exhibits exceptional hydrolytic stability with the CO₂ adsorption isotherm being unchanged following 7 days of steam-treatment (>85% RH) or 6 months of exposure to the atmosphere. The diffusion coefficient of CO₂ in 1 is also 2 orders of magnitude higher than in zeolites currently used in industrial scrubbers. Breakthrough experiments show that 1 only loses 7% of its maximum CO₂ capacity under humid conditions.

Capture cross-section measurements for different elements at neutron energies between 0.5 and 3.0 MeV

International Nuclear Information System (INIS)

Grenier, Gerard; Voignier, Jacques; Joly, Serge.

1981-03-01

Neutron capture cross-sections have been measured for the nuclides: Rb, Y, Nb, Gd, W, Pt, Tl, and for the isotopes 155 Gd, 156 Gd, 157 Gd, 158 Gd, 160 Gd, 182 W, 183 W, 184 W, 186 W, 203 Tl and 205 Tl in the 0.5 MeV to 3.0 MeV neutron energy range. Neutron capture cross-sections are determined through direct γ-ray spectrum emitted by the sample. The gamma-rays are detected by a NaI scintillator surrounded by an annular NaI detector. The time-of-flight method is used. Our results are compared with previous data, evaluations and statistical model calculations [fr

Low energy electron capture in collisions of C3+ with He

International Nuclear Information System (INIS)

Wu, Y.; Qi, Y.Y.; Yan, J.; Wang, J.G.; Li, Y.; Buenker, R.J.; Kato, D.

2009-06-01

Charge transfer processes due to collisions of ground state C 3+ (1s 2 2s 2 S) ions with He atom are investigated using the quantum-mechanical molecular-orbital close-coupling (QMOCC) method for energies between 10 -4 eV/u and 10 3 eV/u. The ab initio adiabatic potential and radial coupling utilized in the QMOCC calculations are obtained from the multi-reference single- and double-excitation configuration interaction (MRD-CI) approach. Total and state-selective single electron capture (SEC) cross sections and rate coefficients are obtained and compared with the available experimental and theoretical data. Good agreement between the measured SEC cross sections and the present calculation is found, but the previous calculation of total rate coefficient using the Landau-Zener model is one or two orders of magnitude smaller than the present result. (author)

The role of human ankle plantar flexor muscle-tendon interaction and architecture in maximal vertical jumping examined in vivo.

Science.gov (United States)

Farris, Dominic James; Lichtwark, Glen A; Brown, Nicholas A T; Cresswell, Andrew G

2016-02-01

Humans utilise elastic tendons of lower limb muscles to store and return energy during walking, running and jumping. Anuran and insect species use skeletal structures and/or dynamics in conjunction with similarly compliant structures to amplify muscle power output during jumping. We sought to examine whether human jumpers use similar mechanisms to aid elastic energy usage in the plantar flexor muscles during maximal vertical jumping. Ten male athletes performed maximal vertical squat jumps. Three-dimensional motion capture and a musculoskeletal model were used to determine lower limb kinematics that were combined with ground reaction force data in an inverse dynamics analysis. B-mode ultrasound imaging of the lateral gastrocnemius (GAS) and soleus (SOL) muscles was used to measure muscle fascicle lengths and pennation angles during jumping. Our results highlighted that both GAS and SOL utilised stretch and recoil of their series elastic elements (SEEs) in a catapult-like fashion, which likely serves to maximise ankle joint power. The resistance of supporting of body weight allowed initial stretch of both GAS and SOL SEEs. A proximal-to-distal sequence of joint moments and decreasing effective mechanical advantage early in the extension phase of the jumping movement were observed. This facilitated a further stretch of the SEE of the biarticular GAS and delayed recoil of the SOL SEE. However, effective mechanical advantage did not increase late in the jump to aid recoil of elastic tissues. © 2016. Published by The Company of Biologists Ltd.

A survey of the Carbon Capture

International Nuclear Information System (INIS)

Jokrllova, J.; Cik, G.; Takacova, A.; Smolinska, M.

2014-01-01

The concentration of carbon dioxide, one of the most important representatives of greenhouse gases in the atmosphere continues to rise. Fossil fuels burned in thermal power plants currently represent 80% of total energy production around the world and are the largest point sources of CO 2 , accounting for approximately 40% of total CO 2 emissions. There are several options for reducing CO 2 emissions: reducing demand, improving production efficiency and carbon capture and storage (CCS, carbon capture and storage). Capture and storage of carbon dioxide is generally a three-step process: 1 st Capture and compression of combustion products, 2 nd transport (mostly pipeline) and 3 rd utilization (eg. production of urea, beverage industry, production of dry ice, etc.). Technologies for CO 2 capturing used in power plants burning fossil fuels can be divided into four groups, each of which requires a completely different approach to CO 2 capture.

Low-energy parity restoration and unification mass scale within maximal symmetries

Directory of Open Access Journals (Sweden)

Ajaya K. Mohanty

1984-01-01

Full Text Available We investigate the hierarchy of gauge boson masses in the maximal grand unified theory by studying the renormalization group equations for the running coupling constants associated with the symmetry breaking of SU(16viaSU(12 q×SU(4 l×U(1 |B|−|L| chain. Particular attention is given to the contribution of Higgs scalars to these equations. It is found that the intermediate mass scale ML, associated with right-handed gauge bosons could be as low as 10 3 GeV only for sin 2θ w(M L as high as 0.265 with α s(M L=0.13. In this chain of symmetry breaking, we have also examined the lowest unification mass that is allowed by the low-energy data for sin 2θ w(M L and the assumed gauge hierarchy. This has been done in two cases; first for the case where SU(3 c is vectorial, second, for the case where SU(3 c is axial. In both cases the lowest unification mass scales were found to be 10 13, 10 11, 10 8 and 10 7 GeV for sin 2θ w(M L = 0.22, 0.24, 0.26,and0.265 respectively with α s(M L = 0.13. The implication of these low unification masses on baryon non-conserving processes is also discussed.

Single-electron capture in He2+-D2 collisions

International Nuclear Information System (INIS)

Bordenave-Montesquieu, D.; Dagnac, R.

1994-01-01

Doubly differential cross sections of single-electron capture were measured for He 2+ impinging on a molecular deuterium target. The investigated collision energies are 4, 6 and 8 keV and the scattering angles range from 10' to 2 o 30' (laboratory frame). The exothermic capture leading to He + (1s) + D 2 +* was found to be the most important process at low energies and angles, whereas the endothermic channels leading to dissociative capture become the main processes at high scattering angles, i.e. at small impact parameters. (author)

Capture, transformation and conversion of the solar energy by the technologies of concentration; Captation, transformation et conversion de l'energie solaire par les technologies a concentration

Energy Technology Data Exchange (ETDEWEB)

Ferriere, A.; Flamant, G

2003-07-01

The specificities of the solar technologies at concentration are: high energy efficiency with increasing possibilities and the possibility of storage the solar energy by heat for a local and short dated utilization or by chemical storage (hydrogen for instance) for a delayed utilization or far from the capture area. This document takes stock on the concentration solar techniques, the electric power production by concentrated solar energy and the performance of concentrated solar plants, the industrial american experience of the SEGS plants, the hydrogen production by concentrated solar energy and discusses the scientific and technological locks. (A.L.B.)

Neutron radiative capture cross section of 232Th in the energy range 0.1 to 1.2 MeV

International Nuclear Information System (INIS)

Jain, H.M.; Kailas, S.

1987-01-01

Recently reported neutron radiative capture cross section of 232 Th measurements in the energy range 0.1 to 1.2 MeV are compared with the calculations based on the statistical model Hauser-Feshbach theory using the spherical optical model transmission coefficients and simple Fermi gas level density formula. The calculations are in good agreement with the recent experimental data, reproducing both the absolute magnitude and the shape exhibited by the excitation function. The results of this comparative study can be used for improving the evaluation of the neutron radiative capture cross section of 232 Th. 16 refs., 3 tables, 4 figures. (author)

Neutron radiative capture cross section of 232Th in the energy range 0.1 to 1.2 MeV

International Nuclear Information System (INIS)

Jain, H.M.; Kailas, S.

1987-03-01

Recently reported neutron radiative capture cross section of Th-232 measurements in the energy range 0.1 to 1.2 MeV are compared with the calculations based on the statistical model Hauser-Feshbach theory using the spherical optical model transmission coefficients and simple Fermi gas level density formula. The calculations are in good agreement with the recent experimental data, reproducing both the absolute magnitude and the shape exhibited by the excitation function. The results of this comparative study can be used for improving the evaluation of the neutron radiative capture cross section of Th-232. (author)

Simultaneous measurement of neutron-induced fission and capture cross sections for {sup 241}Am at neutron energies below fission threshold

Energy Technology Data Exchange (ETDEWEB)

Hirose, K., E-mail: hirose.kentaro@jaea.go.jp [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Nishio, K.; Makii, H.; Nishinaka, I.; Ota, S. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Nagayama, T. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Graduate School of Science and Engineering, Ibaraki University, Mito 310-0056 (Japan); Tamura, N. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Goto, S. [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Andreyev, A.N. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Vermeulen, M.J. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Gillespie, S.; Barton, C. [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Kimura, A.; Harada, H. [Nuclear Science and Engineering Center, JAEA, Tokai, Ibaraki 319-1195 (Japan); Meigo, S. [J-PARC Center, JAEA, Tokai, Ibaraki 319-1195 (Japan); Chiba, S. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Ohtsuki, T. [Research Reactor Institute, Kyoto University, Kumatori-cho S' ennangun,Osaka 590-0494 (Japan)

2017-06-01

Fission and capture reactions were simultaneously measured in the neutron-induced reactions of {sup 241}Am at the spallation neutron facility of the Japan Proton Accelerator Research Complex (J-PARC). Data for the neutron energy range of E{sub n}=0.1–20 eV were taken with the TOF method. The fission events were observed by detecting prompt neutrons accompanied by fission using liquid organic scintillators. The capture reaction was measured by detecting γ rays emitted in the deexcitation of the compound nuclei using the same detectors, where the prompt fission neutrons and capture γ rays were separated by a pulse shape analysis. The cross sections were obtained by normalizing the relative yields at the first resonance to evaluations or other experimental data. The ratio of the fission to capture cross sections at each resonance is compared with those from an evaluated nuclear data library and other experimental data. Some differences were found between the present values and the library/literature values at several resonances.

Capacitance for carbon capture

International Nuclear Information System (INIS)

Landskron, Kai

2018-01-01

Metal recycling: A sustainable, capacitance-assisted carbon capture and sequestration method (Supercapacitive Swing Adsorption) can turn scrap metal and CO 2 into metal carbonates at an attractive energy cost. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Tracking Progress in Carbon Capture and Storage

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-06

At the second Clean Energy Ministerial in Abu Dhabi, April 2011 (CEM 2), the Carbon Capture, Use and Storage Action Group (CCUS AG) presented seven substantive recommendations to Energy Ministers on concrete, near-term actions to accelerate global carbon capture and storage (CCS) deployment. Twelve CCUS AG governments agreed to advance progress against the 2011 recommendations by the third Clean Energy Ministerial (London, 25-26 April 2012) (CEM 3). Following CEM 2, the CCUS AG requested the IEA and the Global CCS Institute to report on progress made against the 2011 recommendations at CEM 3. Tracking Progress in Carbon Capture and Storage: International Energy Agency/Global CCS Institute report to the third Clean Energy Ministerial responds to that request. The report considers a number of key questions. Taken as a whole, what advancements have committed CCUS AG governments made against the 2011 recommendations since CEM 2? How can Energy Ministers continue to drive progress to enable CCS to fully contribute to climate change mitigation? While urgent further action is required in all areas, are there particular areas that are currently receiving less policy attention than others, where efforts could be redoubled? The report concludes that, despite developments in some areas, significant further work is required. CCS financing and industrial applications continue to represent a particularly serious challenge.

Trade-offs in assessing different energy futures: a regional multi-criteria assessment of the role of carbon dioxide capture and storage

International Nuclear Information System (INIS)

Shackley, Simon; McLachlan, Carly

2006-01-01

We examine the responses of stakeholders from the public and private sectors to future energy scenarios for the year 2050 for the North West of England. The main focus of the paper is to examine the stakeholders' reactions to the mitigation option of capturing CO 2 from power stations and storing it in suitable off-shore geological reservoirs. Five energy scenarios were developed which involved a range of levels of CO 2 capture and storage (CCS): Fossilwise, Nuclear Renaissance, Renewable Generation and Spreading the Load high and low scenarios. A multi-criteria assessment method (MCA) was used as a way of elucidating stakeholders' views on the desirability or otherwise of each scenario against nine stakeholder-derived criteria. We found that stakeholders were either business-focused or environment/society-focused with respect to weighting of the criteria. Scoring of the scenarios did not follow such a straightforward pattern. Most respondents scored and weighted strategically and tended to express a clear preference for a form of energy generation. The results suggest that there is unlikely to be a wide-ranging consensus amongst energy stakeholders on the desirability of specific future forms of energy generation. On balance, the results support the inclusion of CCS within scenarios of a low-carbon energy system

'Mathematical model of K Capture and its implications'

International Nuclear Information System (INIS)

Angus, Andrew C.

2000-01-01

The mechanism of K Capture, the nuclear absorption of electron in the K shell, as induced by electricity, is explained in this article. Furthermore, a mathematical model of K Capture is formulated. Then, K Capture is applied to explain the negative results obtained by Steven Jones and the positive results obtained by Pons-Fleischmann in Deuterium Oxide Electrolysis Experiments. The most important implication of K Capture is the possibility of obtaining nuclear energy by fusion at low temperature from heavy water

Balancing Power Absorption and Structural Loading for an Assymmetric Heave Wave-Energy Converter in Regular Waves: Preprint

Energy Technology Data Exchange (ETDEWEB)

Tom, Nathan M.; Madhi, Farshad; Yeung, Ronald W.

2016-07-01

The aim of this paper is to maximize the power-to-load ratio of the Berkeley Wedge: a one-degree-of-freedom, asymmetrical, energy-capturing, floating breakwater of high performance that is relatively free of viscosity effects. Linear hydrodynamic theory was used to calculate bounds on the expected time-averaged power (TAP) and corresponding surge restraining force, pitch restraining torque, and power take-off (PTO) control force when assuming that the heave motion of the wave energy converter remains sinusoidal. This particular device was documented to be an almost-perfect absorber if one-degree-of-freedom motion is maintained. The success of such or similar future wave energy converter technologies would require the development of control strategies that can adapt device performance to maximize energy generation in operational conditions while mitigating hydrodynamic loads in extreme waves to reduce the structural mass and overall cost. This paper formulates the optimal control problem to incorporate metrics that provide a measure of the surge restraining force, pitch restraining torque, and PTO control force. The optimizer must now handle an objective function with competing terms in an attempt to maximize power capture while minimizing structural and actuator loads. A penalty weight is placed on the surge restraining force, pitch restraining torque, and PTO actuation force, thereby allowing the control focus to be placed either on power absorption or load mitigation. Thus, in achieving these goals, a per-unit gain in TAP would not lead to a greater per-unit demand in structural strength, hence yielding a favorable benefit-to-cost ratio. Demonstrative results in the form of TAP, reactive TAP, and the amplitudes of the surge restraining force, pitch restraining torque, and PTO control force are shown for the Berkeley Wedge example.

EJECTION AND CAPTURE DYNAMICS IN RESTRICTED THREE-BODY ENCOUNTERS

International Nuclear Information System (INIS)

Kobayashi, Shiho; Hainick, Yanir; Sari, Re'em; Rossi, Elena M.

2012-01-01

We study the tidal disruption of binaries by a massive point mass (e.g., the black hole at the Galactic center), and we discuss how the ejection and capture preference between unequal-mass binary members depends on which orbit they approach the massive object. We show that the restricted three-body approximation provides a simple and clear description of the dynamics. The orbit of a binary with mass m around a massive object M should be almost parabolic with an eccentricity of |1 – e| ∼ 1/3 1/3 times the binary rotation velocity, it would be abruptly disrupted, and the energy change at the encounter can be evaluated in a simple disruption model. We evaluate the probability distributions for the ejection and capture of circular binary members and for the final energies. In principle, for any hyperbolic (elliptic) orbit, the heavier member has more chance to be ejected (captured), because it carries a larger fraction of the orbital energy. However, if the orbital energy is close to zero, the difference between the two members becomes small, and there is practically no ejection and capture preferences. The preference becomes significant when the orbital energy is comparable to the typical energy change at the encounter. We discuss its implications to hypervelocity stars and irregular satellites around giant planets.

Direct neutron capture and related mechanisms

International Nuclear Information System (INIS)

Lynn, J.E.; Raman, S.

1990-01-01

We consider the evidence for the role of direct and related mechanisms in neutron capture at low and medium energies. Firstly, we compare the experimental data on the thermal neutron cross sections for El transitions in light nuclei with careful estimates of direct capture. Over the full range of light nuclei with small cross sections direct capture is found to be the predominant mechanism, in some cases being remarkable accurate, but in a few showing evidence for collective effects. When resonance effects become substantial there is evidence for an important contribution from the closely related valence mechanism, but full agreement with the data in such cases appears to require the introduction of a more generalised valence model. The possibility of direct and valence mechanisms playing a role in M1 capture is studied, and it is concluded that in light nuclei at relatively low gamma ray energies, it does indeed play some role. In heavier nuclei it appears that the evidence, especially from the correlations between E1 and M1 transitions to the same final states, favours the hypothesis that the main transition strength is governed by the M1 giant resonance. 31 refs., 2 tabs

Energy Capture Optimization for an Adaptive Wave Energy Converter

NARCIS (Netherlands)

Barradas Berglind, Jose de Jesus; Meijer, Harmen; van Rooij, Marijn; Clemente Pinol, Silvia; Galvan Garcia, Bruno; Prins, Wouter; Vakis, Antonis I.; Jayawardhana, Bayu

2016-01-01

Wave energy has great potential as a renewable energy source, and can therefore contribute significantly to the proportion of renewable energy in the global energy mix. This is especially important since energy mixes with high renewable penetration have become a worldwide priority. One solution to

Subtask 2.18 - Advancing CO₂ Capture Technology: Partnership for CO₂ Capture (PCO₂C) Phase III

Energy Technology Data Exchange (ETDEWEB)

Kay, John; Azenkeng, Alexander; Fiala, Nathan; Jensen, Melanie; Laumb, Jason; Leroux, Kerryanne; McCollor, Donald; Stanislowski, Joshua; Tolbert, Scott; Curran, Tyler

2016-03-31

Industries and utilities continue to investigate ways to decrease their carbon footprint. Carbon capture and storage (CCS) can enable existing power generation facilities to meet the current national CO₂ reduction goals. The Partnership for CO2 Capture Phase III focused on several important research areas in an effort to find ways to decrease the cost of capture across both precombustion and postcombustion platforms. Two flue gas pretreatment technologies for postcombustion capture, an SO₂ reduction scrubbing technology from Cansolv Technologies Inc. and the Tri-Mer filtration technology that combines particulate, NOx, and SO₂ control, were evaluated on the Energy & Environmental Research Center’s (EERC’s) pilot-scale test system. Pretreating the flue gas should enable more efficient, and therefore less expensive, CO₂ capture. Both technologies were found to be effective in pretreating flue gas prior to CO₂ capture. Two new postcombustion capture solvents were tested, one from the Korea Carbon Capture and Sequestration R&D Center (KCRC) and one from CO₂ Solutions Incorporated. Both of these solvents showed the ability to capture CO₂ while requiring less regeneration energy, which would reduce the cost of capture. Hydrogen separation membranes from Commonwealth Scientific and Industrial Research Organisation were evaluated through precombustion testing. They are composed of vanadium alloy, which is less expensive than the palladium alloys that are typically used. Their performance was comparable to that of other membranes that have been tested at the EERC. Aspen Plus® software was used to model the KCRC and CO₂ Solutions solvents and found that they would result in significantly improved overall plant performance. The modeling effort also showed that the parasitic steam load at partial capture of 45% is less than half that of 90% overall capture, indicating savings that

Current status of fast-neutron-capture calculations

International Nuclear Information System (INIS)

Gardner, D.G.

1982-01-01

This work is primarily concerned with the calculation of neutron capture cross sections and capture gamma-ray spectra, in the framework of the Hauser-Feshbach statistical model and for neutrons from the resonance region up to several MeV. An argument is made that, for applied purposes such as constructing evaluated cross-section libraries, nonstatistical capture mechanisms may be completely neglected at low energies and adequately approximated at high energies in a simple way. The use of gamma-ray strength functions to obtain radiation widths is emphasized. Using the reaction 89 Y + n as an example, the problems encountered in trying to construct a case that could be run equivalently on two different nuclear reaction codes are illustrated, and the effects produced by certain parameter variations are discussed

Capacitance for carbon capture

Energy Technology Data Exchange (ETDEWEB)

Landskron, Kai [Department of Chemistry, Lehigh University, Bethlehem, PA (United States)

2018-03-26

Metal recycling: A sustainable, capacitance-assisted carbon capture and sequestration method (Supercapacitive Swing Adsorption) can turn scrap metal and CO{sub 2} into metal carbonates at an attractive energy cost. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Radiative proton capture to the first excited state of sup 29 P nucleus at subbarrier energies

Energy Technology Data Exchange (ETDEWEB)

Matulewicz, T; Dabrowska, M; Decowski, P; Kicinska-Habior, M; Sikora, B [Warsaw Univ. (Poland). Inst. Fizyki Doswiadczalnej; Toke, J [Rochester Univ., NY (USA). Nuclear Structure Research Lab.; Somorjai, E [Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete

1985-08-01

Differential cross sections at 0 deg and 90 deg measured for {sup 28}Si(p,{gamma}{sub 1}){sup 29}P reaction at proton energy range 2.3-2.9 MeV have been analyzed in terms of the direct-semidirect capture model extended by the effective potential approach. Spectroscopic factor of the first excited states of {sup 29}P nucleus was found to be 0.10+-0.05. 9 refs., 1 fig. (author).

New rules of thumb maximizing energy efficiency in street lighting with discharge lamps: The general equations for lighting design

Science.gov (United States)

Peña-García, A.; Gómez-Lorente, D.; Espín, A.; Rabaza, O.

2016-06-01

New relationships between energy efficiency, illuminance uniformity, spacing and mounting height in public lighting installations were derived from the analysis of a large sample of outputs generated with a widely used software application for lighting design. These new relationships greatly facilitate the calculation of basic lighting installation parameters. The results obtained are also based on maximal energy efficiency and illuminance uniformity as a premise, which are not included in more conventional methods. However, these factors are crucial since they ensure the sustainability of the installations. This research formulated, applied and analysed these new equations. The results of this study highlight their usefulness in rapid planning and urban planning in developing countries or areas affected by natural disasters where engineering facilities and computer applications for this purpose are often unavailable.

Algal capture of carbon dioxide; biomass generation as a tool for greenhouse gas mitigation with reference to New Zealand energy strategy and policy

International Nuclear Information System (INIS)

Packer, Mike

2009-01-01

The use of algae to capture carbon dioxide as a method for greenhouse gas mitigation is discussed. A small fraction of the sunlight energy that bathes Earth is captured by photosynthesis and drives most living systems. Life on Earth is carbon-based and the energy is used to fix atmospheric carbon dioxide into biological material (biomass), indeed fossil fuels that we consume today are a legacy of mostly algal photosynthesis. Algae can be thought of as marine and freshwater plants that have higher photosynthetic efficiencies than terrestrial plants and are more efficient capturing carbon (Box 1). They have other favourable characteristics for this purpose. In the context of New Zealand energy strategy and policy I discuss progress in growing algae and seaweeds with emphasis on their application for exhaust flue carbon recycling for possible generation of useful biomass. I also introduce schemes utilising wild oceanic algae for carbon dioxide sequestration and the merits and possible adverse effects of using this approach. This paper is designed as an approachable review of the science and technology for policy makers and a summary of the New Zealand policy environment for those wishing to deploy biological carbon sequestration.

Maximizers versus satisficers

OpenAIRE

Andrew M. Parker; Wandi Bruine de Bruin; Baruch Fischhoff

2007-01-01

Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007). Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002), we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions...

Enzymes in CO2 Capture

DEFF Research Database (Denmark)

Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

Review of the fundamentals of the neutron-capture reaction

International Nuclear Information System (INIS)

Chrien, R.E.

1982-01-01

Fifty years of research into the nature of the radiative capture reaction mechanisms is briefly summarized. A variety of such mechanisms is exploited to explain neutron capture over nine decades of neutron energy

MAXIMIZING MAGNETIC ENERGY STORAGE IN THE SOLAR CORONA

International Nuclear Information System (INIS)

Wolfson, Richard; Drake, Christina; Kennedy, Max

2012-01-01

The energy that drives solar eruptive events such as coronal mass ejections (CMEs) almost certainly originates in coronal magnetic fields. Such energy may build up gradually on timescales of days or longer before its sudden release in an eruptive event, and the presence of free magnetic energy capable of rapid release requires nonpotential magnetic fields and associated electric currents. For magnetic energy to power a CME, that energy must be sufficient to open the magnetic field to interplanetary space, to lift the ejecta against solar gravity, and to accelerate the material to speeds of typically several hundred km s –1 . Although CMEs are large-scale structures, many originate from relatively compact active regions on the solar surface—suggesting that magnetic energy storage may be enhanced when it takes place in smaller magnetic structures. This paper builds on our earlier work exploring energy storage in large-scale dipolar and related bipolar magnetic fields. Here we consider two additional cases: quadrupolar fields and concentrated magnetic bipoles intended to simulate active regions. Our models yield stored energies whose excess over that of the corresponding open field state can be greater than 100% of the associated potential field energy; this contrasts with maximum excess energies of only about 20% for dipolar and symmetric bipolar configurations. As in our previous work, energy storage is enhanced when we surround a nonpotential field with a strong overlying potential field that acts to 'hold down' the nonpotential flux as its magnetic energy increases.

Climate Strategy with CO2 Capture from the Air

Energy Technology Data Exchange (ETDEWEB)

Keith, D.W. [Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB (Canada); Ha-Duong, M. [CNRS-CIRED, Campus du Jardin Tropical, 45 bis, av. de la Belle Gabrielle, 94736 Nogent sur Marne CEDEX (France); Stolaroff, J.K. [Department of Engineering and Public Policy, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA 15213 (United States)

2006-01-15

It is physically possible to capture CO2 directly from the air and immobilize it in geological structures. Air capture differs from conventional mitigation in three key aspects. First, it removes emissions from any part of the economy with equal ease or difficulty, so its cost provides an absolute cap on the cost of mitigation. Second, it permits reduction in concentrations faster than the natural carbon cycle: the effects of irreversibility are thus partly alleviated. Third, because it is weakly coupled to existing energy infrastructure, air capture may offer stronger economies of scale and smaller adjustment costs than the more conventional mitigation technologies. We assess the ultimate physical limits on the amount of energy and land required for air capture and describe two systems that might achieve air capture at prices under 200 and 500 $/tC using current technology. Like geoengineering, air capture limits the cost of a worst-case climate scenario. In an optimal sequential decision framework with uncertainty, existence of air capture decreases the need for near-term precautionary abatement. The long-term effect is the opposite; assuming that marginal costs of mitigation decrease with time while marginal climate change damages increase, then air capture increases long-run abatement. Air capture produces an environmental Kuznets curve, in which concentrations are returned to preindustrial levels.

Pre-Combustion Carbondioxide Capture in Integrated Gasification Combined Cycles

Directory of Open Access Journals (Sweden)

M. Zeki YILMAZOĞLU

2010-02-01

Full Text Available Thermal power plants have a significant place big proportion in the production of electric energy. Thermal power plants are the systems which converts heat energy to mechanical energy and also mechanical energy to electrical energy. Heat energy is obtained from combustion process and as a result of this, some harmful emissions, like CO2, which are the reason for global warming, are released to atmosphere. The contribution of carbondioxide to global warming has been exposed by the previous researchs. Due to this fact, clean energy technologies are growing rapidly all around the world. Coal is generally used in power plants and when compared to other fossil energy sources unit electricity production cost is less than others. When reserve rate is taken into account, coal may be converted to energy in a more efficient and cleaner way. The aim for using the clean coal technologies are to eradicate the harmful emissions of coal and to store the carbondioxide, orginated from combustion, in different forms. In line with this aim, carbondioxide may be captured by either pre-combustion, by O2/CO2 recycling combustion systems or by post combustion. The integrated gasification combined cycles (IGCC are available in pre-combustion capture systems, whereas in O2/CO2 recycling combustion systems there are ultrasuper critical boiler technologies and finally flue gas washing systems by amines exists in post combustion systems. In this study, a pre-combustion CO2 capture process via oxygen blown gasifiers is compared with a conventional power plant in terms of CO2 emissions. Captured carbondioxide quantity has been presented as a result of the calculations made throughout the study.

Modus operandi for maximizing energy efficiency and increasing permeate flux of community scale solar powered reverse osmosis systems

International Nuclear Information System (INIS)

Vyas, Harsh; Suthar, Krunal; Chauhan, Mehul; Jani, Ruchita; Bapat, Pratap; Patel, Pankaj; Markam, Bhupendra; Maiti, Subarna

2015-01-01

Highlights: • Experimental data on energy efficient photovoltaic powered reverse osmosis system. • Synergetic management of electrical, thermal and hydraulic energies. • Use of reflectors, heat exchanger and turgo turbine. - Abstract: Photovoltaic powered reverse osmosis systems can only be made cost effective if they are made highly energy efficient. In this work we describe a protocol to maximize energy efficiency and increase permeate flux in a fully integrated installation of such a system. The improved system consisted of (i) photovoltaic array fitted with suitably positioned and aligned North–South V-trough reflectors to enhance power output from the array; (ii) direct contact heat exchanger fitted on the rear of the photovoltaic modules for active cooling of the same while safeguarding the terminals from short-circuit and corrosion; (iii) use of reverse osmosis feed water as heat exchange medium while taking due care to limit the temperature rise of feed water; (iv) enhancing permeate flux through the rise in feed water temperature; (v) turgo-turbine for conversion of hydraulic energy in reverse osmosis reject water into mechanical energy to provide part of the energy to replace booster pump utilized in the reverse osmosis unit. The V-trough reflectors onto the photovoltaic modules with thermal energy recovery system brought about an increase in power output of 40% and the synergistic effect of (i)–(iv) gave rise to total permeate volume boost of 59%. Integration of (v) resulted in 56% and 26% saving of electrical power when the reverse osmosis plant was operated by battery bank and direct photovoltaic array respectively

Annual Report: Carbon Capture (30 September 2012)

Energy Technology Data Exchange (ETDEWEB)

Luebke, David; Morreale, Bryan; Richards, George; Syamlal, Madhava

2014-04-16

Capture of carbon dioxide (CO{sub 2}) is a critical component in reducing greenhouse gas emissions from fossil fuel-based processes. The Carbon Capture research to be performed is aimed at accelerating the development of efficient, cost-effective technologies which meet the post-combustion programmatic goal of capture of 90% of the CO{sub 2} produced from an existing coal-fired power plant with less than a 35% increase in the cost of electricity (COE), and the pre-combustion goal of 90% CO{sub 2} capture with less than a 10% increase in COE. The specific objective of this work is to develop innovative materials and approaches for the economic and efficient capture of CO{sub 2} from coal-based processes, and ultimately assess the performance of promising technologies at conditions representative of field application (i.e., slip stream evaluation). The Carbon Capture research includes seven core technical research areas: post-combustion solvents, sorbents, and membranes; pre-combustion solvents, sorbents, and membranes; and oxygen (O{sub 2}) production. The goal of each of these tasks is to develop advanced materials and processes that are able to reduce the energy penalty and cost of CO{sub 2} (or O{sub 2}) separation over conventional technologies. In the first year of development, materials will be examined by molecular modeling, and then synthesized and experimentally characterized at lab scale. In the second year, they will be tested further under ideal conditions. In the third year, they will be tested under realistic conditions. The most promising materials will be tested at the National Carbon Capture Center (NCCC) using actual flue or fuel gas. Systems analyses will be used to determine whether or not materials developed are likely to meet the Department of Energy (DOE) COE targets. Materials which perform well and appear likely to improve in performance will be licensed for further development outside of the National Energy Technology Laboratory (NETL

Single-electron capture for 2-8 keV incident energy and direct scattering at 6 keV in He[sup 2+]-He collisions

Energy Technology Data Exchange (ETDEWEB)

Bordenave-Montesquieu, D.; Dagnac, R. (Toulouse-3 Univ., 31 (France). Centre de Physique Atomique)

1992-06-14

We studied the single-electron capture as well as the direct processes occurring when a He[sup 2+] ion is scattered by a He target. Doubly differential cross sections were measured for single-electron capture with a collision energy ranging from 2 to 8 keV and a scattering angle varying from 10' to 3[sup o]30' (laboratory frame). Single-electron capture into excited states of He[sup +] was found to be the dominant process, confirming a previous experimental study. Elastic scattering and ionization differential cross sections were measured for E = 6 keV. (Author).

Recent development of capture of CO2

CERN Document Server

Chavez, Rosa Hilda

2014-01-01

"Recent Technologies in the capture of CO2" provides a comprehensive summary on the latest technologies available to minimize the emission of CO2 from large point sources like fossil-fuel power plants or industrial facilities. This ebook also covers various techniques that could be developed to reduce the amount of CO2 released into the atmosphere. The contents of this book include chapters on oxy-fuel combustion in fluidized beds, gas separation membrane used in post-combustion capture, minimizing energy consumption in CO2 capture processes through process integration, characterization and application of structured packing for CO2 capture, calcium looping technology for CO2 capture and many more. Recent Technologies in capture of CO2 is a valuable resource for graduate students, process engineers and administrative staff looking for real-case analysis of pilot plants. This eBook brings together the research results and professional experiences of the most renowned work groups in the CO2 capture field...

Synovectomy by Neutron capture

International Nuclear Information System (INIS)

Vega C, H.R.; Torres M, C.

1998-01-01

The Synovectomy by Neutron capture has as purpose the treatment of the rheumatoid arthritis, illness which at present does not have a definitive curing. This therapy requires a neutron source for irradiating the articulation affected. The energy spectra and the intensity of these neutrons are fundamental since these neutrons induce nuclear reactions of capture with Boron-10 inside the articulation and the freely energy of these reactions is transferred at the productive tissue of synovial liquid, annihilating it. In this work it is presented the neutron spectra results obtained with moderator packings of spherical geometry which contains in its center a Pu 239 Be source. The calculations were realized through Monte Carlo method. The moderators assayed were light water, heavy water base and the both combination of them. The spectra obtained, the average energy, the neutron total number by neutron emitted by source, the thermal neutron percentage and the dose equivalent allow us to suggest that the moderator packing more adequate is what has a light water thickness 0.5 cm (radius 2 cm) and 24.5 cm heavy water (radius 26.5 cm). (Author)

Optimal Operation of Network-Connected Combined Heat and Powers for Customer Profit Maximization

Directory of Open Access Journals (Sweden)

Da Xie

2016-06-01

Full Text Available Network-connected combined heat and powers (CHPs, owned by a community, can export surplus heat and electricity to corresponding heat and electric networks after community loads are satisfied. This paper proposes a new optimization model for network-connected CHP operation. Both CHPs’ overall efficiency and heat to electricity ratio (HTER are assumed to vary with loading levels. Based on different energy flow scenarios where heat and electricity are exported to the network from the community or imported, four profit models are established accordingly. They reflect the different relationships between CHP energy supply and community load demand across time. A discrete optimization model is then developed to maximize the profit for the community. The models are derived from the intervals determined by the daily operation modes of CHP and real-time buying and selling prices of heat, electricity and natural gas. By demonstrating the proposed models on a 1 MW network-connected CHP, results show that the community profits are maximized in energy markets. Thus, the proposed optimization approach can help customers to devise optimal CHP operating strategies for maximizing benefits.

Polarized proton capture reaction /sup 7/Li(p,. gamma. )/sup 8/Be in the energy range from 380 to 960 keV

Energy Technology Data Exchange (ETDEWEB)

Ulbricht, J; Arnold, W; Berg, H; Huttel, E; Krause, H H; Clausnitzer, G [Giessen Univ. (Germany, F.R.). Abt. Grossgeraete (Angewandte Kernphysik)

1977-09-05

The polarized proton capture in /sup 7/Li was used to study the reaction mechanism and to obtain spectroscopic information on the /sup 8/Be nucleus. Gamma-ray angular distributions of the analyzing power were measured as a function of proton energy from Esub(p) = 380-960 keV with three Ge(Li) detectors simultaneously. The excitation functions of the cross section and the analyzing power are strongly energy dependent. The data were analyzed unambiguously and represented by three R-matrix elements, two M1 and one E1. The energy dependence of the two M1 matrix elements agrees with the well-known two 1/sup +/ resonances at Esub(x) = 17.642 and 18.157 MeV. The energy dependence of the E1 matrix element shows a smooth background presumably caused by a direct-capture mechanism, and furthermore, a resonant contribution, which is a significant suggestion of a new 1/sup -/ state in the /sup 8/Be system at Esub(x) = 17.70 MeV with a width of GAMMAsub(p) = 180 keV.

Recent investigations on electronic capture in atomic collisions

International Nuclear Information System (INIS)

Rivarola, R.D.

1988-01-01

In this work, electron capture processes in ion-atom collisions at various impact energy ranges are dicussed: i) intermediate non-relativistic energy; ii) high energy; iii) high relativistic energy. Much attention is given to the development and use of distorted wave models. (A.C.A.S.) [pt

Dynamic Operation and Simulation of Post-Combustion CO2 Capture

DEFF Research Database (Denmark)

Gaspar, Jozsef; Gladis, Arne; Jørgensen, John Bagterp

2016-01-01

Thermal power need to operate, on a daily basis, with frequent and fast load changes to balance the large variations of intermittent energy sources, such as wind and solar energy. To make the integration of carbon capture to power plants economically and technically feasible, the carbon capture...... process has to be able to follow these fast and large load changes without decreasing the overall performance of the carbon capture plant. Therefore, dynamic models for simulation, optimization and control system design are essential. In this work, we compare the transient behavior of the model against...

Study of thermal neutron capture in 58 Ni

International Nuclear Information System (INIS)

Carbonari, A.W.; Pecequilo, B.R.S.

1988-08-01

The energies and intensities of the primary gamma-rays from 58 Ni (n, γ) 59 Ni reaction have been measured with a Ge(li) pair-spectrometer in the region of 3.7 to 9.3 MeV. The thermal neutron capture cross section of 58 Ni was determined to be 4.52 +- 0.10 by summing the primary transition intensities. The neutron separation energy was found to be 8999.93 +- 0.34 KeV. It is shown that the decay of the capture state is non-statistical and that there is a strong correlation between the strengths of excitation of levels by the (n, γ) and (d,p) reactions. These results are discussed in terms of a direct neutron capture reaction mechanism. (author) [pt

Capture orbits around asteroids by hitting zero-velocity curves

Science.gov (United States)

Wang, Wei; Yang, Hongwei; Zhang, Wei; Ma, Guangfu

2017-12-01

The problem of capturing a spacecraft from a heliocentric orbit into a high parking orbit around binary asteroids is investigated in the current study. To reduce the braking Δ V, a new capture strategy takes advantage of the three-body gravity of the binary asteroid to lower the inertial energy before applying the Δ V. The framework of the circular restricted three-body problem (CR3BP) is employed for the binary asteroid system. The proposed capture strategy is based on the mechanism by which inertial energy can be decreased sharply near zero-velocity curves (ZVCs). The strategy has two steps, namely, hitting the target ZVC and raising the periapsis by a small Δ V at the apoapsis. By hitting the target ZVC, the positive inertial energy decreases and becomes negative. Using a small Δ V, the spacecraft inserts into a bounded orbit around the asteroid. In addition, a rotating mass dipole model is employed for elongated asteroids, which leads to dynamics similar to that of the CR3BP. With this approach, the proposed capture strategy can be applied to elongated asteroids. Numerical simulations validate that the proposed capture strategy is applicable for the binary asteroid 90 Antiope and the elongated asteroid 216 Kleopatra.

Neutron capture and fission cross section of Americium-243 in the energy range from 5 to 250 keV

International Nuclear Information System (INIS)

Wisshak, K.; Kaeppeler, F.

1983-04-01

The neutron capture and subthreshold fission cross section of 243 Am was measured in the energy range from 5 to 250 keV using 197 Au and 235 U as the respective standards. Neutrons were produced via the 7 Li(p,n) and the T(p,n) reaction with the Karlsruhe 3-MV pulsed Van de Graaff accelerator. Capture events were detected by two MoxonRae detectors with graphite and bismuthgraphite converters, respectively. Fission events were registered by a NE-213 liquid scintillator with pulse-shape discriminator equipment. Flight paths as short as 50-70 mm were used to obtain optimum signal-to-background ratio. After correction for the different efficiency of the individual converter materials the capture cross section could be determined with a total uncertainty of 3-6%. The respective values for the fission cross section are 8-12%. The results are compared to predictions of recent evaluations, which in some cases are severely discrepant. (orig.)

Entropy maximization

Indian Academy of Sciences (India)

Abstract. It is shown that (i) every probability density is the unique maximizer of relative entropy in an appropriate class and (ii) in the class of all pdf f that satisfy. ∫ fhi dμ = λi for i = 1, 2,...,...k the maximizer of entropy is an f0 that is pro- portional to exp(. ∑ ci hi ) for some choice of ci . An extension of this to a continuum of.

Capturing method for integral three-dimensional imaging using multiviewpoint robotic cameras

Science.gov (United States)

Ikeya, Kensuke; Arai, Jun; Mishina, Tomoyuki; Yamaguchi, Masahiro

2018-03-01

Integral three-dimensional (3-D) technology for next-generation 3-D television must be able to capture dynamic moving subjects with pan, tilt, and zoom camerawork as good as in current TV program production. We propose a capturing method for integral 3-D imaging using multiviewpoint robotic cameras. The cameras are controlled through a cooperative synchronous system composed of a master camera controlled by a camera operator and other reference cameras that are utilized for 3-D reconstruction. When the operator captures a subject using the master camera, the region reproduced by the integral 3-D display is regulated in real space according to the subject's position and view angle of the master camera. Using the cooperative control function, the reference cameras can capture images at the narrowest view angle that does not lose any part of the object region, thereby maximizing the resolution of the image. 3-D models are reconstructed by estimating the depth from complementary multiviewpoint images captured by robotic cameras arranged in a two-dimensional array. The model is converted into elemental images to generate the integral 3-D images. In experiments, we reconstructed integral 3-D images of karate players and confirmed that the proposed method satisfied the above requirements.

Double electron capture by protons in collisions with H2

International Nuclear Information System (INIS)

Salazar-Zepeda, M.H.; Gleason, Cristian; Gonzalez, Eduardo; Gonzalez-Magana, O.; Hinojosa, Guillermo

2010-01-01

Double electron capture of protons in collisions with molecular hydrogen in the energy range 1.5-10 keV was studied by measuring the resulting H - velocity distributions. In this paper, a technique that provides experimental evidence about double capture mechanisms is proposed. In addition, cross-sections for this process were measured in the energy range of 1-5 keV.

Entropy Maximization

Indian Academy of Sciences (India)

It is shown that (i) every probability density is the unique maximizer of relative entropy in an appropriate class and (ii) in the class of all pdf that satisfy ∫ f h i d = i for i = 1 , 2 , … , … k the maximizer of entropy is an f 0 that is proportional to exp ⁡ ( ∑ c i h i ) for some choice of c i . An extension of this to a continuum of ...

Thermal neutron capture gamma-rays

International Nuclear Information System (INIS)

Tuli, J.K.

1983-01-01

The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,α), E = thermal, reactions for which the residual nucleus mass number is greater than or equal to 45 are included. These correspond to evaluations published in Nuclear Data Sheets. The publication source data are contained in the Evaluated Nuclear Structure Data File (ENSDF). The data presented here do not involve any additional evaluation. Appendix I lists all the residual nuclides for which the data are included here. Appendix II gives a cumulated index to A-chain evaluations including the year of publication. The capture gamma ray data are given in two tables - the Table 1 is the list of all gamma rays seen in (n,#betta#) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide

Review of the neutron capture process in fission reactors

International Nuclear Information System (INIS)

Poenitz, W.P.

1981-07-01

The importance of the neutron capture process and the status of the more important cross section data are reviewed. The capture in fertile and fissile nuclei is considered. For thermal reactors the thermal to epithermal capture ratio for 238 U and 232 Th remains a problem though some improvements were made with more recent measurements. The capture cross section of 238 U in the fast energy range remains quite uncertain and a long standing discrepancy for the calculated versus experimental central reaction rate ratio C28/F49 persists. Capture in structural materials, fission product nuclei and the higher actinides is also considered

Capture of Planetesimals into a Circumterrestrial Swarm

Science.gov (United States)

Weidenschilling, S. J.

1985-01-01

The lunar origin model considered in this report involves processing of protolunar material through a circumterrestrial swarm of particles. Once such a swarm has formed, it can gain mass by capturing infalling planetesimals and ejecta from giant impacts on the Earth, although the angular momentum supply from these sources remains a problem. The first stage of formation of a geocentric swarm by capture of planetesimals from initially heliocentric orbits is examined. The only plausible capture mechanism that is not dependent on very low approach velocities is the mutual collision of planetesimals passing within Earth's sphere of influence. The dissipation of energy in inelastic collisions or accretion events changes the value of the Jacobi parameter, allowing capture into bound geocentric orbits. This capture scenario was tested directly by many body numerical integration of planetesimal orbits in near Earth space.

Electron capture by highly charged ions from surfaces and gases

International Nuclear Information System (INIS)

Allen, F.

2008-01-01

In this study highly charged ions produced in Electron Beam Ion Traps are used to investigate electron capture from surfaces and gases. The experiments with gas targets focus on spectroscopic measurements of the K-shell x-rays emitted at the end of radiative cascades following electron capture into Rydberg states of Ar 17+ and Ar 18+ ions as a function of collision energy. The ions are extracted from an Electron Beam Ion Trap at an energy of 2 keVu -1 , charge-selected and then decelerated down to 5 eVu -1 for interaction with an argon gas target. For decreasing collision energies a shift to electron capture into low orbital angular momentum capture states is observed. Comparative measurements of the K-shell x-ray emission following electron capture by Ar 17+ and Ar 18+ ions from background gas in the trap are made and a discrepancy in the results compared with those from the extraction experiments is found. Possible explanations are discussed. For the investigation of electron capture from surfaces, highly charged ions are extracted from an Electron Beam Ion Trap at energies of 2 to 3 keVu -1 , charge-selected and directed onto targets comprising arrays of nanoscale apertures in silicon nitride membranes. The highly charged ions implemented are Ar 16+ and Xe 44+ and the aperture targets are formed by focused ion beam drilling in combination with ion beam assisted thin film deposition, achieving hole diameters of 50 to 300 nm and aspect ratios of 1:5 to 3:2. After transport through the nanoscale apertures the ions pass through an electrostatic charge state analyzer and are detected. The percentage of electron capture from the aperture walls is found to be much lower than model predictions and the results are discussed in terms of a capillary guiding mechanism. (orig.)

Maximally incompatible quantum observables

Energy Technology Data Exchange (ETDEWEB)

Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ziman, Mario, E-mail: ziman@savba.sk [RCQI, Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 84511 Bratislava (Slovakia); Faculty of Informatics, Masaryk University, Botanická 68a, 60200 Brno (Czech Republic)

2014-05-01

The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

Maximally incompatible quantum observables

International Nuclear Information System (INIS)

Heinosaari, Teiko; Schultz, Jussi; Toigo, Alessandro; Ziman, Mario

2014-01-01

The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

Maximizing Energy Savings for Small Businesses | Buildings | NREL

Science.gov (United States)

energy efficiency of a building: Dollar sign Increase Profits Increase Profits Reduce operating costs and cash flows Understanding the risks and how to manage them Finding financial incentives for energy Transaction Costs and Analysis of Economic Risk, focused on overcoming two barriers to financing energy

Single electron capture in N^+ -(Ne, Kr, Xe) collisions

Science.gov (United States)

Reyes, Pedro G.; Castillo, Fermin; Martinez, Horacio

2001-05-01

Total cross sections for single electron capture of N^+ ions impinging on Ne, Kr and Xe were measured in the energy range of 1.5 to 5.0 keV. The electron capture cross sections for all the targets studied are found to be in excellent agreement with previous data in the low-energy range. The present data together with previous measurements give a general shape of the whole curve of single electron capture cross sections for the N^+ - Ne system. For the cases of N^+ - (Kr, Xe) systems, semiempirical calculation using the two-state approximation are in very good agreement with present cross sections data. Research supported by DGAPA IN-100392 and CONACyT 32175-E

Multiphonon capture processes in self-assembled quantum dots

DEFF Research Database (Denmark)

Magnúsdóttir, Ingibjörg; Uskov, A.; Bischoff, Svend

2001-01-01

We investigate capture of carriers from states in the continuous part of the energy spectrum into the discrete states of self-assembled InAs/GaAs QDs via emission of one or two phonons. We are not aware of any other investigations of two-phonon mediated capture processes in QDs, but we show...

Earth 2075 (CO2) - can Ocean-Amplified Carbon Capture (oacc) Impart Atmospheric CO2-SINKING Ability to CCS Fossil Energy?

Science.gov (United States)

Fry, R.; Routh, M.; Chaudhuri, S.; Fry, S.; Ison, M.; Hughes, S.; Komor, C.; Klabunde, K.; Sethi, V.; Collins, D.; Polkinghorn, W.; Wroobel, B.; Hughes, J.; Gower, G.; Shkolnik, J.

2017-12-01

Previous attempts to capture atmospheric CO2 by algal blooming were stalled by ocean viruses, zooplankton feeding, and/or bacterial decomposition of surface blooms, re-releasing captured CO2 instead of exporting it to seafloor. CCS fossil energy coupling could bypass algal bloom limits—enabling capture of 10 GtC/yr atmospheric CO2 by selective emiliania huxleyi (EHUX) blooming in mid-latitude open oceans, far from coastal waters and polar seas. This could enable a 500 GtC drawdown, 350 ppm restoration by 2050, 280 ppm CO2 by 2075, and ocean pH 8.2. White EHUX blooms could also reflect sunlight back into outer space and seed extra ocean cloud cover, via DMS release, to raise albedo 1.8%—restoring preindustrial temperature (ΔT = 0°C) by 2030. Open oceans would avoid post-bloom anoxia, exclusively a coastal water phenomenon. The EHUX calcification reaction initially sources CO2, but net sinking prevails in follow-up equilibration reactions. Heavier-than-water EHUX sink captured CO2 to the sea floor before surface decomposition occurs. Seeding EHUX high on their nonlinear growth curve could accelerate short-cycle secondary open-ocean blooming—overwhelming mid-latitude viruses, zooplankton, and competition from other algae. Mid-latitude "ocean deserts" exhibit low viral, zooplankton, and bacterial counts. Thermocline prevents nutrient upwelling that would otherwise promote competing algae. Adding nitrogen nutrient would foster exclusive EHUX blooming. Elevated EHUX seed levels could arise from sealed, pH-buffered, floating, seed-production bioreactors infused with 10% CO2 from carbon feedstock supplied by inland CCS fossil power plants capturing 90% of emissions as liquid CO2. Deep-water SPAR platforms extract natural gas from beneath the sea floor. On-platform Haber and pH processing could convert extracted CH4 to buffered NH4+ nutrient, enabling ≥0.7 GtC/yr of bioreactor seed production and 10 GtC/yr of amplified secondary open-ocean CO2 capture—making CCS

Single electron capture differential cross section in H+ + He collisions at intermediate and high collision energies

International Nuclear Information System (INIS)

Abufager, P N; Fainstein, P D; MartInez, A E; Rivarola, R D

2005-01-01

The generalized continuum distorted wave-eikonal initial state (CDW-EIS II) approximation is employed to study differential cross sections (DCS) for single electron capture in H + + He collisions at intermediate and high energies. Present results are compared with theoretical calculations obtained using the previous CDW-EIS formulation in order to show the importance of the description of the bound and continuum target states in the entrance and exit channels, respectively. Both DCS are also shown together with other theoretical results and with experimental data

Algal Turf Scrubbers: Cleaning Water While Capturing Solar Energy

International Nuclear Information System (INIS)

Adey, W.

2009-01-01

Algal Turfs and Algal Turf Scrubbers (ATS) Algal Turfs are bio diverse communities of unicellular to filamentous algae of all major algal phyla. Algal Turf Scrubbers (ATS) are bioengineered ecosystems dominated by algal turfs. They clean water to very high quality, and remove CO 2 from the atmosphere by capturing solar energy at rates 10 times that of agriculture and 50 times that of forestry. ATS was invented at the Smithsonian Institution, by scientist, Walter Adey in the 1980s as a tool for controlling water quality in highly diverse model ecosystems. The technology received extensive R and D for aqua cultural, municipal, and industrial water cleaning by Dr. Adey, using venture capital, through the 1990s. Later, Hydro Mentia, Inc., of Ocala, Florida, engineered ATS to landscape scale of 20-50 Mgpd (it is important to note that this is a modular system, capable of expanding to any size.) A 2005 independent study of ATS, by the South Florida Water Management District and the IFAS Institute of the University of Florida, certified ATS as 5-100 times more cost efficient at removing nutrients from Everglades canal waters than the next competitor, the STA, a managed marsh system. ATS and STA were the final contestants in a 15-year study of nine technologies, and ATS was the only technology that created a use able byproduct.

Energy spectra and asymmetry of charged particle emission in the muon minus capture by nuclei

International Nuclear Information System (INIS)

Balandin, M.P.; Grebenyuk, V.M.; Sinov, V.G.; Konin, A.D.

1978-01-01

Energy spectra of separated-by-mass single-charged particles at the capture of 130 MeV negative muons by carbon, oxygen, magnesium and sulphur have been measured. The experimental results are compared with the theoretical calculations at the assumption of preequilibrium decay of collective states described by the hydrodynamical model. The measurement of asymmetry of charged particle emission in sulphur and megnesium was carried out by hte method of muon spin precession in a magnetic field. Theoretical curves describe correctly the exponential spectra character, but the yields obtained are 2-3 times less than the experimental results

Radiative electron capture by channeled ions

International Nuclear Information System (INIS)

Pitarke, J.M.; Ritchie, R.H.; Tennessee Univ., Knoxville, TN

1989-01-01

Considerable experimental data have been accumulated relative to the emission of photons accompanying electron capture by swift, highly stripped atoms penetrating crystalline matter under channeling conditions. Recent data suggest that the photon energies may be less than that expected from simple considerations of transitions from the valence band of the solid to hydrogenic states on the moving ion. We have studied theoretically the impact parameter dependence of the radiative electron capture (REC) process, the effect of the ion's wake and the effect of capture from inner shells of the solid on the photon emission probability, using a statistical approach. Numerical comparisons of our results with experiment are made. 13 refs., 6 figs

Dryland Agrivoltaics: A novel approach to collocating food production and solar renewable energy to maximize food production, water savings, and energy generation

Science.gov (United States)

Barron-Gafford, G.; Escobedo, E. B.; Smith, J.; Raub, H.; Jimenez, J. R.; Sutter, L., Jr.; Barnett-Moreno, I.; Blackett, D. T.; Thompson, M. S.; Minor, R. L.; Pavao-Zuckerman, M.

2017-12-01

Conventional understanding of land use asserts an inherent "zero-sum-game" of competition between renewable energy and agricultural food production. This discourse is so fundamentally entrenched that it drives most current policy around conservation practices, land and water allotments for agriculture, and permitting for large-scale renewable energy installations. We are investigating a novel approach to solve a problem key to our environment and economy in drylands by creating a hybrid of collocated "green" agriculture and "grey" solar photovoltaic (PV) infrastructure to maximize agricultural production while improving renewable energy production. We are monitoring atmospheric microclimatic conditions, soil moisture, plant ecophysiological function, and biomass production within both this novel "agrivoltaics" ecosystem and in traditional PV installations and agricultural settings (control plot) to quantify tradeoffs associated with this approach. We have found that levels of soil moisture remained higher after each irrigation event within the soils under the agrivoltaics installation than the traditional agricultural setting due to the shading provided by the PV panels overhead. We initiated a drought treatment, which underscored the water-savings under the agrivoltaics installation and increased water use efficiency in this system. We hypothesized that we will see more temperature and drought stresses on photosynthetic capacity and water use efficiency in the control plants relative to the agrivoltaic installation, and we found that several food crops either experienced significantly more production within the agrivoltaics area, whereas others resulted in nearly equal production but at significant water savings. Combined with localized cooling of the PV panels resulting from the transpiration from the vegetative "understory", we are finding a win-win-win at the food-water-energy nexus. photo credit: Bob Demers/UANews

Design and manufacturing rules for maximizing the performance of polycrystalline piezoelectric bending actuators

International Nuclear Information System (INIS)

Jafferis, Noah T; Smith, Michael J; Wood, Robert J

2015-01-01

Increasing the energy and power density of piezoelectric actuators is very important for any weight-sensitive application, and is especially crucial for enabling autonomy in micro/milli-scale robots and devices utilizing this technology. This is achieved by maximizing the mechanical flexural strength and electrical dielectric strength through the use of laser-induced melting or polishing, insulating edge coating, and crack-arresting features, combined with features for rigid ground attachments to maximize force output. Manufacturing techniques have also been developed to enable mass customization, in which sheets of material are pre-stacked to form a laminate from which nearly arbitrary planar actuator designs can be fabricated using only laser cutting. These techniques have led to a 70% increase in energy density and an increase in mean lifetime of at least 15× compared to prior manufacturing methods. In addition, measurements have revealed a doubling of the piezoelectric coefficient when operating at the high fields necessary to achieve maximal energy densities, along with an increase in the Young’s modulus at the high compressive strains encountered—these two effects help to explain the higher performance of our actuators as compared to that predicted by linear models. (paper)

Preliminary carbon dioxide capture technical and economic feasibility study evaluation of carbon dioxide capture from existing fired plants by hybrid sorption using solid sorbents

Energy Technology Data Exchange (ETDEWEB)

Benson, Steven; Envergex, Srivats; Browers, Bruce; Thumbi, Charles

2013-01-01

Barr Engineering Co. was retained by the Institute for Energy Studies (IES) at University of North Dakota (UND) to conduct a technical and economic feasibility analysis of an innovative hybrid sorbent technology (CACHYS™) for carbon dioxide (CO2) capture and separation from coal combustion–derived flue gas. The project team for this effort consists of the University of North Dakota, Envergex LLC, Barr Engineering Co., and Solex Thermal Science, along with industrial support from Allete, BNI Coal, SaskPower, and the North Dakota Lignite Energy Council. An initial economic and feasibility study of the CACHYS™ concept, including definition of the process, development of process flow diagrams (PFDs), material and energy balances, equipment selection, sizing and costing, and estimation of overall capital and operating costs, is performed by Barr with information provided by UND and Envergex. The technology—Capture from Existing Coal-Fired Plants by Hybrid Sorption Using Solid Sorbents Capture (CACHYS™)—is a novel solid sorbent technology based on the following ideas: reduction of energy for sorbent regeneration, utilization of novel process chemistry, contactor conditions that minimize sorbent-CO2 heat of reaction and promote fast CO2 capture, and a low-cost method of heat management. The technology’s other key component is the use of a low-cost sorbent.

Electron-capture ratios in radio-active decay

International Nuclear Information System (INIS)

Pelt, J. van.

1978-01-01

A review of the theory of electron capture is given and expressions for the electron-capture ratios derived. Attention is paid to the calculations of exchange and overlap correction factors. The theoretical results are then compared with experimental values on the basis of two recently published compilations. The experimental set-up used in this investigation is described and the analysis of the scintillation spectra discussed. Measurements on 131 Ba, 106 Agsup(m) and 196 Au are described and values derived for the exchange and overlap corrections and for the atomic electron-capture transition energy Qsub(EC). (Auth.)

Maximal combustion temperature estimation

International Nuclear Information System (INIS)

Golodova, E; Shchepakina, E

2006-01-01

This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

Developing maximal neuromuscular power: part 2 - training considerations for improving maximal power production.

Science.gov (United States)

Cormie, Prue; McGuigan, Michael R; Newton, Robert U

2011-02-01

This series of reviews focuses on the most important neuromuscular function in many sport performances: the ability to generate maximal muscular power. Part 1, published in an earlier issue of Sports Medicine, focused on the factors that affect maximal power production while part 2 explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability to generate maximal power during complex motor skills is of paramount importance to successful athletic performance across many sports. A crucial issue faced by scientists and coaches is the development of effective and efficient training programmes that improve maximal power production in dynamic, multi-joint movements. Such training is referred to as 'power training' for the purposes of this review. Although further research is required in order to gain a deeper understanding of the optimal training techniques for maximizing power in complex, sports-specific movements and the precise mechanisms underlying adaptation, several key conclusions can be drawn from this review. First, a fundamental relationship exists between strength and power, which dictates that an individual cannot possess a high level of power without first being relatively strong. Thus, enhancing and maintaining maximal strength is essential when considering the long-term development of power. Second, consideration of movement pattern, load and velocity specificity is essential when designing power training programmes. Ballistic, plyometric and weightlifting exercises can be used effectively as primary exercises within a power training programme that enhances maximal power. The loads applied to these exercises will depend on the specific requirements of each particular sport and the type of movement being trained. The use of ballistic exercises with loads ranging from 0% to 50% of one-repetition maximum (1RM) and

Basic Research Needs for Carbon Capture: Beyond 2020

Energy Technology Data Exchange (ETDEWEB)

Alivisatos, Paul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Buchanan, Michelle [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2010-03-04

This report is based on a SC/FE workshop on Carbon Capture: Beyond 2020, held March 4–5, 2010, to assess the basic research needed to address the current technical bottlenecks in carbon capture processes and to identify key research priority directions that will provide the foundations for future carbon capture technologies. The problem of thermodynamically efficient and scalable carbon capture stands as one of the greatest challenges for modern energy researchers. The vast majority of US and global energy use derives from fossil fuels, the combustion of which results in the emission of carbon dioxide into the atmosphere. These anthropogenic emissions are now altering the climate. Although many alternatives to combustion are being considered, the fact is that combustion will remain a principal component of the global energy system for decades to come. Today’s carbon capture technologies are expensive and cumbersome and energy intensive. If scientists could develop practical and cost-effective methods to capture carbon, those methods would at once alter the future of the largest industry in the world and provide a technical solution to one of the most vexing problems facing humanity. The carbon capture problem is a true grand challenge for today’s scientists. Postcombustion CO2 capture requires major new developments in disciplines spanning fundamental theoretical and experimental physical chemistry, materials design and synthesis, and chemical engineering. To start with, the CO2 molecule itself is thermodynamically stable and binding to it requires a distortion of the molecule away from its linear and symmetric arrangement. This binding of the gas molecule cannot be too strong, however; the sheer quantity of CO2 that must be captured ultimately dictates that the capture medium must be recycled over and over. Hence the CO2 once bound, must be released with relatively little energy input. Further, the CO2 must be rapidly and selectively pulled out of a mixture

Proceedings of the fourth workshop on radiative capture 1990, October 19--21, 1990

International Nuclear Information System (INIS)

Wender, S.A.; Gossett, C.; Feldman, J.

1991-01-01

The Fourth Workshop on Radiative Capture was held at the Berkeley Conference Center, Berkeley, CA, on October 19--21, 1990. This two-day workshop, which had seventeen presentations, addressed current theoretical and experimental issues in the field of nucleon capture and other nuclear radiative processes. The scientific program was divided into three sessions: (1) radiative capture at low energies; (2) few-nucleon systems and capture at intermediate energies; and (3) nucleon capture and other radiative processes. This proceedings of the conference contains the abstracts of the presented talks and the transparencies used by the speakers. Summary papers of the talks are also included when they were supplied by the speaker

Privacy-preserving screen capture: towards closing the loop for health IT usability.

Science.gov (United States)

Cooley, Joseph; Smith, Sean

2013-08-01

As information technology permeates healthcare (particularly provider-facing systems), maximizing system effectiveness requires the ability to document and analyze tricky or troublesome usage scenarios. However, real-world health IT systems are typically replete with privacy-sensitive data regarding patients, diagnoses, clinicians, and EMR user interface details; instrumentation for screen capture (capturing and recording the scenario depicted on the screen) needs to respect these privacy constraints. Furthermore, real-world health IT systems are typically composed of modules from many sources, mission-critical and often closed-source; any instrumentation for screen capture can rely neither on access to structured output nor access to software internals. In this paper, we present a tool to help solve this problem: a system that combines keyboard video mouse (KVM) capture with automatic text redaction (and interactively selectable unredaction) to produce precise technical content that can enrich stakeholder communications and improve end-user influence on system evolution. KVM-based capture makes our system both application-independent and OS-independent because it eliminates software-interface dependencies on capture targets. Using a corpus of EMR screenshots, we present empirical measurements of redaction effectiveness and processing latency to demonstrate system performances. We discuss how these techniques can translate into instrumentation systems that improve real-world health IT deployments. Copyright © 2013 Elsevier Inc. All rights reserved.

Non-destructive assay of 242Pu by resonance neutron capture

International Nuclear Information System (INIS)

Kane, W.R.; Lu, Ming-Shih; Aronson, A.; Forman, L.; Vanier, P.E.

1995-01-01

For the accurate assay of plutonium by neutron correlation measurements, especially for material derived from high-burnup reactor fuel, the content of 242 Pu in a sample must be determined. Since 242 Pu has a long half-life (387,000 yr) and decays to 238 U by alpha particle emission with the accompanying emission of only weak, low-energy gamma rays, gamma-ray spectrometry methods which are ordinarily employed to determine the isotopic composition of a plutonium sample are not feasible for 242 Pu. The existence of a resonance in the neutron capture cross section of 242 Pu at an energy of 2.67 electron volts (eV) with a large (72, 000 barn) cross section affords the possibility for the quantitative assay of this isotope by epithermal neutron capture. Essential for this purpose is an appropriately designed geometry of neutron moderators and absorbers which will provide maximum flux in the eV region while suppressing thermal neutron capture by the fissile plutonium isotopes. Signatures for neutron capture in 242 Pu include the decay of 243 Pu (4.9 hr), prompt capture gamma rays (total energy 5.034 MeV), and the decay of an isomeric state (330 nanosecond). Experiments to determine the feasibility of this approach are currently in progress

Capture of Heat Energy from Diesel Engine Exhaust

Energy Technology Data Exchange (ETDEWEB)

Chuen-Sen Lin

2008-12-31

Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data

Self-supporting power plant. Capturing evaporated water and save energy a new source of water

Energy Technology Data Exchange (ETDEWEB)

Daal, Ludwin; Vos, Frank de [KEMA Netherlands BV, Arnhem (Netherlands). Process and Cooling Water; KEMA Energy Consulting Co.Ltd, Beijing (China); Wageningen Univ. (Netherlands). Environmental Systems Analysis; Heijboer, Rob [KEMA Netherlands BV, Arnhem (Netherlands). Process and Cooling Water; Bekker, Bert [KEMA Energy Consulting Co.Ltd, Beijing (China); Gao, Xiu Xiu [Wageningen Univ. (Netherlands). Environmental Systems Analysis

2013-07-01

One of the major challenges of this century is the provision of water for a growing population and industry. The shortage in water resources in arid areas requires the availability of more efficient and cheaper water production processes. In some arid regions water is even more important than electricity. A large source of water is found in the form of evaporated water emitted from different industrial processes. If for example 20% of the evaporated water from the flue gas stream of a coal fired power plant would be captured, the plant would be self-supporting from a process water point of view. This is about 30m{sup 3} of water per hour. The results of the proof of principle project (2001-2008) show that >40% recovery can be achieved. Also an overall energy efficiency improvement can be achieved for industrial plants that reheat their flue gases. Calculations show that this can be about 1% overall efficiency for a coal fired power plant utilizing flue gas reheating. With an installed capacity of more than 600GWe in China, this energy saving results in a very large economic and fuel (coal) impact. This energy efficiency will most likely be the driving force to implement the technology in both water rich and water poor regions. For the capture of evaporated water no chemicals are used, there is no waste water formed and corrosion attack in stacks is mitigated. These results have led to the set up of a large international project named CapWa which aims to produce a membrane modular system suitable for industrial applications within 2-3years. The produced demin water from this system should be competitive with existing demin water technologies. The starting point will be the water vapour selective composite membranes that are developed in the proof of principle project. The CapWa project started in 2010 and consists of 14 partners of which 9 from the EU, 3 from the African continent and 2 from the Middle East.

Comparison of the BNAB-78 and ENDF/B-V evaluated 238U radiative capture data in the energy range from 0.5 to 15 MeV

International Nuclear Information System (INIS)

Tolstikov, V.A.

1991-01-01

Evaluations of the 238 U capture cross-section as given in the BNAB-78 and ENDF/B-V evaluated data libraries are intercompared and their values compared to recently published data which had not been included in these evaluations. It is concluded that there is a need to re-assess the earlier experimental data, particularly those based on activation measurements, taking secondary neutron reactions and scattering effects into account. It is recommended that a precision measurement of the capture cross-section and its dependence on energy be done in the 1-7 MeV energy range. (author). 18 refs, 1 fig

Proton capture to the ground and excited states in light nuclei

International Nuclear Information System (INIS)

Anghinolfi, M.; Corvisiero, P.; Guarnone, M.; Ricco, G.; Sanzone, M.; Taiuti, M.; Zucchiatti, A.

1984-01-01

Proton capture experiments, when performed with good resolution, generally provide two different kinds of physical information; the ground-state pγ/sub o/ cross section, which is related, through the detailed balance, to the inverse photonuclear γp/sub o/ reaction; the advantage of capture experiments is the definite kinematics, corresponding to monochromatic photons in γp reactions, and a more precise beam monitoring. The pγ/sub x/ cross section to the various excited states of the final nucleus; this information is typical of capture experiments, since excited nuclear targets are not available. Many laboratories performed extensive capture experiments at excitation energies up to the GDR region, but only recently few groups (Ohio, Triangle and Genova Universities) extended the investigation to energies above the GDR. In fact more severe experimental problems arise at higher energies: since the pγ differential cross sections range in this energy region between 0.1 and 1Γb/sr, while competitive reactions have two or three order of magnitude higher cross sections, the signal-to-background ratio is very low. The data analysis strongly depends on the detector line shape, scarsely known at photon energies above 20 MeV; a very accurate knowledge of the detector response function is therefore necessary

Electron capture by He2+ ions in collisions with H and H2 at impact energies below 10 keV

International Nuclear Information System (INIS)

Nutt, W.L.; McCullough, R.W.; Brady, K.; Shah, M.B.; Gilbody, H.B.

1978-01-01

Total cross sections for the process He 2+ + H(1s) → He + (Σn, 1) + H + involving capture into all final bound states of He + have been determined for 3 He 2+ ions in the range 1.5-9.0 keV using a furnace-target technique previously employed for similar measurements at higher impact energies. Measured cross sections are considerably smaller than those measured previously by Fite et al (Proc. R.Soc.; A268:527 (1962)) and are in better accord with recent theoretical estimates. A likely explanation for the discrepancy is given in terms of the corresponding cross sections for electron capture in He 2+ -H 2 collisions which have also been determined. (author)

The effects of low energy electron capture collisions (H0 + Csup(n+)) on the particle and energy balance of Tokamak plasmas

International Nuclear Information System (INIS)

Hogan, J.T.

1982-01-01

To illustrate the way in which atomic data provides enlightenment in the search for understandable (and thus extrapolable) confinement models, the scope of the paper is restricted to electron capture collisions involving H 0 and multiply-charged ions. Many such foreign (impurity) multiply-charged ion species are found in plasma discharges, as a result of gas recycling and damage to the surrounding surfaces by energetic plasma particles. Typical 'low-Z' ions are carbon and oxygen; the major constituents of the stainless steel wall (Fe, Ni, Cr) are intermediate impurities, while 'high-Z' impurities (Mo, W) enter from 'limiter' plates which constrict the hot plasma zone to reduce direct plasma-wall contact. In this discussion, however, attention is given only to applications of data involving H 0 + Csup(n+) → H + + Csup((n-1)+) reactions with energy 10 eV to 2 keV. This energy range is typical of the plasma edge in present devices. (Auth.)

Neutron capture cross section of ^243Am

Science.gov (United States)

Jandel, M.

2009-10-01

The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for neutron capture cross section measurement on ^243Am. The high granularity of DANCE (160 BaF2 detectors in a 4π geometry) enables the efficient detection of prompt gamma-rays following neutron capture. DANCE is located on the 20.26 m neutron flight path 14 (FP14) at the Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center (LANSCE). The methods and techniques established in [1] were used for the determination of the ^243Am neutron capture cross section. The cross sections were obtained in the range of neutron energies from 0.02 eV to 400 keV. The resonance region was analyzed using SAMMY7 and resonance parameters were extracted. The results will be compared to existing evaluations and calculations. Work was performed under the auspices of the U.S. Department of Energy at Los Alamos National Laboratory by the Los Alamos National Security, LLC under Contract No. DE-AC52-06NA25396 and at Lawrence Livermore National Laboratory by the Lawrence Livermore National Security, LLC under Contract No. DE-AC52-07NA27344. [4pt] [1] M. Jandel et al., Phys. Rev. C78, 034609 (2008)

Nonlinear model dynamics for closed-system, constrained, maximal-entropy-generation relaxation by energy redistribution

International Nuclear Information System (INIS)

Beretta, Gian Paolo

2006-01-01

We discuss a nonlinear model for relaxation by energy redistribution within an isolated, closed system composed of noninteracting identical particles with energy levels e i with i=1,2,...,N. The time-dependent occupation probabilities p i (t) are assumed to obey the nonlinear rate equations τ dp i /dt=-p i ln p i -α(t)p i -β(t)e i p i where α(t) and β(t) are functionals of the p i (t)'s that maintain invariant the mean energy E=Σ i=1 N e i p i (t) and the normalization condition 1=Σ i=1 N p i (t). The entropy S(t)=-k B Σ i=1 N p i (t)ln p i (t) is a nondecreasing function of time until the initially nonzero occupation probabilities reach a Boltzmann-like canonical distribution over the occupied energy eigenstates. Initially zero occupation probabilities, instead, remain zero at all times. The solutions p i (t) of the rate equations are unique and well defined for arbitrary initial conditions p i (0) and for all times. The existence and uniqueness both forward and backward in time allows the reconstruction of the ancestral or primordial lowest entropy state. By casting the rate equations in terms not of the p i 's but of their positive square roots √(p i ), they unfold from the assumption that time evolution is at all times along the local direction of steepest entropy ascent or, equivalently, of maximal entropy generation. These rate equations have the same mathematical structure and basic features as the nonlinear dynamical equation proposed in a series of papers ending with G. P. Beretta, Found. Phys. 17, 365 (1987) and recently rediscovered by S. Gheorghiu-Svirschevski [Phys. Rev. A 63, 022105 (2001);63, 054102 (2001)]. Numerical results illustrate the features of the dynamics and the differences from the rate equations recently considered for the same problem by M. Lemanska and Z. Jaeger [Physica D 170, 72 (2002)]. We also interpret the functionals k B α(t) and k B β(t) as nonequilibrium generalizations of the thermodynamic-equilibrium Massieu

Capture cross sections for Cr, Fe and Ni

International Nuclear Information System (INIS)

Corvi, F.

1990-01-01

Since stainless steel represents about 25% of the volume of a fast power reactor, its constituent elements strongly influence its two main neutronic parameters: critical enrichment and breeding gain. Also, capture in the narrow p and d-wave resonances of Cr, Fe and Ni contributes as much as 10 to 15% of the Doppler coefficient of reactivity. Following sensitivity calculations, typical accuracy requirements in the energy range 0.1-100 keV are 5-10% for capture in Fe and 10-20% for capture in Ni and Cr. 11 refs, 2 tabs

Maximizing Lifetime of Wireless Sensor Networks with Mobile Sink Nodes

Directory of Open Access Journals (Sweden)

Yourong Chen

2014-01-01

Full Text Available In order to maximize network lifetime and balance energy consumption when sink nodes can move, maximizing lifetime of wireless sensor networks with mobile sink nodes (MLMS is researched. The movement path selection method of sink nodes is proposed. Modified subtractive clustering method, k-means method, and nearest neighbor interpolation method are used to obtain the movement paths. The lifetime optimization model is established under flow constraint, energy consumption constraint, link transmission constraint, and other constraints. The model is solved from the perspective of static and mobile data gathering of sink nodes. Subgradient method is used to solve the lifetime optimization model when one sink node stays at one anchor location. Geometric method is used to evaluate the amount of gathering data when sink nodes are moving. Finally, all sensor nodes transmit data according to the optimal data transmission scheme. Sink nodes gather the data along the shortest movement paths. Simulation results show that MLMS can prolong network lifetime, balance node energy consumption, and reduce data gathering latency under appropriate parameters. Under certain conditions, it outperforms Ratio_w, TPGF, RCC, and GRND.

Automatic optimization of core loading patterns to maximize cycle energy production within operational constraints

International Nuclear Information System (INIS)

Hobson, G.H.; Turinsky, P.J.

1986-01-01

Computational capability has been developed to automatically determine the core loading pattern which minimizes fuel cycle costs for a pressurized water reactor. Equating fuel cycle cost minimization with core reactivity maximization, the objective is to determine the loading pattern which maximizes core reactivity at end-of-cycle while satisfying the power peaking constraint throughout the cycle and region average discharge burnup limit. The method utilizes a two-dimensional, coarse mesh, finite difference scheme to evaluate core reactivity and fluxes for an initial reference loading pattern as a function of cycle burnup. First order perturbation theory is applied to determine the effects of assembly shuffling on reactivity, power distribution, and end-of-cycle burnup

Computational Modeling of Mixed Solids for CO2 CaptureSorbents

Energy Technology Data Exchange (ETDEWEB)

Duan, Yuhua

2015-01-01

Since current technologies for capturing CO2 to fight global climate change are still too energy intensive, there is a critical need for development of new materials that can capture CO2 reversibly with acceptable energy costs. Accordingly, solid sorbents have been proposed to be used for CO2 capture applications through a reversible chemical transformation. By combining thermodynamic database mining with first principles density functional theory and phonon lattice dynamics calculations, a theoretical screening methodology to identify the most promising CO2 sorbent candidates from the vast array of possible solid materials has been proposed and validated. The calculated thermodynamic properties of different classes of solid materials versus temperature and pressure changes were further used to evaluate the equilibrium properties for the CO2 adsorption/desorption cycles. According to the requirements imposed by the pre- and post- combustion technologies and based on our calculated thermodynamic properties for the CO2 capture reactions by the solids of interest, we were able to screen only those solid materials for which lower capture energy costs are expected at the desired pressure and temperature conditions. Only those selected CO2 sorbent candidates were further considered for experimental validations. The ab initio thermodynamic technique has the advantage of identifying thermodynamic properties of CO2 capture reactions without any experimental input beyond crystallographic structural information of the solid phases involved. Such methodology not only can be used to search for good candidates from existing database of solid materials, but also can provide some guidelines for synthesis new materials. In this presentation, we apply our screening methodology to mixing solid systems to adjust the turnover temperature to help on developing CO2 capture Technologies.

Single-electron capture in He[sup 2+]-D[sub 2] collisions

Energy Technology Data Exchange (ETDEWEB)

Bordenave-Montesquieu, D.; Dagnac, R. (Toulouse-3 Univ., 31 (France))

1994-02-14

Doubly differential cross sections of single-electron capture were measured for He[sup 2+] impinging on a molecular deuterium target. The investigated collision energies are 4, 6 and 8 keV and the scattering angles range from 10' to 2[sup o]30' (laboratory frame). The exothermic capture leading to He[sup +] (1s) + D[sub 2][sup +*] was found to be the most important process at low energies and angles, whereas the endothermic channels leading to dissociative capture become the main processes at high scattering angles, i.e. at small impact parameters. (author).

Electron capture by highly charged ions from surfaces and gases

Energy Technology Data Exchange (ETDEWEB)

Allen, F.

2008-01-11

In this study highly charged ions produced in Electron Beam Ion Traps are used to investigate electron capture from surfaces and gases. The experiments with gas targets focus on spectroscopic measurements of the K-shell x-rays emitted at the end of radiative cascades following electron capture into Rydberg states of Ar{sup 17+} and Ar{sup 18+} ions as a function of collision energy. The ions are extracted from an Electron Beam Ion Trap at an energy of 2 keVu{sup -1}, charge-selected and then decelerated down to 5 eVu{sup -1} for interaction with an argon gas target. For decreasing collision energies a shift to electron capture into low orbital angular momentum capture states is observed. Comparative measurements of the K-shell x-ray emission following electron capture by Ar{sup 17+} and Ar{sup 18+} ions from background gas in the trap are made and a discrepancy in the results compared with those from the extraction experiments is found. Possible explanations are discussed. For the investigation of electron capture from surfaces, highly charged ions are extracted from an Electron Beam Ion Trap at energies of 2 to 3 keVu{sup -1}, charge-selected and directed onto targets comprising arrays of nanoscale apertures in silicon nitride membranes. The highly charged ions implemented are Ar{sup 16+} and Xe{sup 44+} and the aperture targets are formed by focused ion beam drilling in combination with ion beam assisted thin film deposition, achieving hole diameters of 50 to 300 nm and aspect ratios of 1:5 to 3:2. After transport through the nanoscale apertures the ions pass through an electrostatic charge state analyzer and are detected. The percentage of electron capture from the aperture walls is found to be much lower than model predictions and the results are discussed in terms of a capillary guiding mechanism. (orig.)

AUC-Maximizing Ensembles through Metalearning.

Science.gov (United States)

LeDell, Erin; van der Laan, Mark J; Petersen, Maya

2016-05-01

Area Under the ROC Curve (AUC) is often used to measure the performance of an estimator in binary classification problems. An AUC-maximizing classifier can have significant advantages in cases where ranking correctness is valued or if the outcome is rare. In a Super Learner ensemble, maximization of the AUC can be achieved by the use of an AUC-maximining metalearning algorithm. We discuss an implementation of an AUC-maximization technique that is formulated as a nonlinear optimization problem. We also evaluate the effectiveness of a large number of different nonlinear optimization algorithms to maximize the cross-validated AUC of the ensemble fit. The results provide evidence that AUC-maximizing metalearners can, and often do, out-perform non-AUC-maximizing metalearning methods, with respect to ensemble AUC. The results also demonstrate that as the level of imbalance in the training data increases, the Super Learner ensemble outperforms the top base algorithm by a larger degree.

Measurements of Capture Efficiency of Range Hoods in Homes

DEFF Research Database (Denmark)

Simone, Angela; Sherman, Max H.; Walker, Iain S.

2015-01-01

mapped the pollution distribution in the room, and showed that the pollutants escape more at the sides of the cooktop. These preliminary results suggest that more measurements should be conducted investigating the capture efficiency at different pollutant source temperature, size and location...... want a range hood to use little energy and have high capture efficiency to minimize the required air flow to capture the cooking pollutants. Currently there are no standards for rating range hoods for capture efficiency In this study, measurements of range hood capture efficiency were made a tight...... kitchen-room built in a laboratory chamber, and a methodology for standardizing measurement of capture efficiency was developed. The results for a wall mounted range hood, showed that up to half of the cooking pollutants were not captured at a flow rate of 230 m3/h. A more detailed set of measurements...

Maximization of primary energy savings of solar heating and cooling systems by transient simulations and computer design of experiments

International Nuclear Information System (INIS)

Calise, F.; Palombo, A.; Vanoli, L.

2010-01-01

In this paper, the simulation of the performance of solar-assisted heating and cooling systems is analyzed. Three different plant layouts are considered: (i) the first one consists of evacuated solar collectors and a single-stage LiBr-H 2 O absorption chiller; here in order to integrate the system in case of insufficient solar radiation, an electric water-cooled chiller is activated; (ii) configuration of the secondly considered system is similar to the first one, but the absorption chiller and the solar collector area are sized for balancing about 30% of the building cooling load only; (iii) the layout of the thirdly considered system differs from the first one since the auxiliary electric chiller is replaced by a gas-fired heater. Such system configurations also include: circulation pumps, storage tanks, feedback controllers, mixers, diverters and on/off hysteresis controllers. All such devices are modelled for maximizing the system energy efficiency. In order to simulate the systems' performance for dynamic heating/cooling loads, a single-lumped capacitance building is also modelled and implemented in the computer code. A cost model is also developed in order to calculate the systems' operating and capital costs. All the models and the relative simulations are carried out by TRNSYS. A design of experiment procedure is also included. By such tool the effects of the system operating parameters' variation on the relative energy efficiency are analyzed. In addition, the set of synthesis/design variables maximizing the system's energetic performance can be also identified. The annual primary energy saving is chosen as the optimization objective function, whereas collector slope, pump flows, set-point temperatures and tank volume are selected as optimizing system design variables. A case study was developed for an office building located in South Italy. Here, the energetic and the economic analysis for all the three considered system layouts are carried out. The

State selective single-electron capture in O6++Nacollisions

NARCIS (Netherlands)

Knoop, S; Keim, M; Ludde, HJ; Kirchner, T; Morgenstern, [No Value; Hoekstra, R

2005-01-01

Single-electron capture in O6+ + Na collisions at 1-9 keV/amu collision energy has been studied both experimentally and theoretically. Partial cross sections for electron capture into n = 5, 6, 7, 8 and n >= 9 have been obtained from target recoil momenta measured by the technique of MOTRIMS and are

Electron capture from H(2s) by H+ at low energies

International Nuclear Information System (INIS)

Blanco, S.A.; Falcon, C.A.; Piacentini, R.D.

1986-01-01

Total cross sections for resonant electron capture by protons from metastable H(2s) targets have been computed in a six-state molecular close-coupling formalism. Transitions between degenerate sublevels of the L shell of the target occurring at large internuclear distances have been taken into account in the impact parameter approximation. Cross sections are presented for impact velocities between 0.05 and 0.3 au. The results are compared with theoretical calculations for capture from H(2s) by Li 3+ , C 6+ and N 7+ . (author)

Physiological reactions to capture in hibernating brown bears.

Science.gov (United States)

Evans, Alina L; Singh, Navinder J; Fuchs, Boris; Blanc, Stéphane; Friebe, Andrea; Laske, Timothy G; Frobert, Ole; Swenson, Jon E; Arnemo, Jon M

2016-01-01

Human disturbance can affect animal life history and even population dynamics. However, the consequences of these disturbances are difficult to measure. This is especially true for hibernating animals, which are highly vulnerable to disturbance, because hibernation is a process of major physiological changes, involving conservation of energy during a resource-depleted time of year. During the winters of 2011-15, we captured 15 subadult brown bears ( Ursus arctos ) and recorded their body temperatures ( n  = 11) and heart rates ( n = 10) before, during and after capture using biologgers. We estimated the time for body temperature and heart rate to normalize after the capture event. We then evaluated the effect of the captures on the pattern and depth of hibernation and the day of den emergence by comparing the body temperature of captured bears with that of undisturbed subadult bears ( n  = 11). Both body temperature and heart rate increased during capture and returned to hibernation levels after 15-20 days. We showed that bears required 2-3 weeks to return to hibernation levels after winter captures, suggesting high metabolic costs during this period. There were also indications that the winter captures resulted in delayed den emergence.

CO{sub 2} capture and utilization for enhanced oil recovery

Energy Technology Data Exchange (ETDEWEB)

Vilhelmsen, P.J.; Well, W. van; Nielsen, Charles [DONG Energy Generation, Fredericia (Denmark); Harrar, W.; Reffstrup, J. [DONG Energy Exploration and Production, Hoersholm (Denmark)

2007-05-15

CO{sub 2} is an international theme and the cap-and-trade systems under implementation will lead to significant alterations in the energy market and in the energy system altogether. A possible technical step to reduce atmospheric emissions is CO{sub 2} capture and the utilisation of the CO{sub 2} for Enhanced Oil Recovery (EOR). CO{sub 2} capture is to some extent a know technology but has not yet been optimised and commercialised for power plant utilisation. Correspondingly CO{sub 2} utilisation for EOR is a known method in other areas of the world where the reservoir conditions are different from those of the North Sea. For several years Elsam and Energi E2, part of DONG Energy, have worked on reducing CO{sub 2} emissions through increased efficiency at the coal-fired power plants, and this work has now been extended to also include capture and utilisation of CO{sub 2}. DONG E and P within DONG Energy has started work on the utilisation of CO{sub 2} for EOR at the company's fields in the North Sea. Based on DONG Energy's interest in working through the whole value chain from power plants to EOR utilisation in the North Sea, this paper describes our experience with CO{sub 2} capture at the trial plant CASTOR at Esbjerg power plant and the actual work of investigating and preparing the pilot test of CO{sub 2} for EOR in the North Sea. The paper also illustrates the perspectives of retrofitting the existing fleet of super critical coal-fired power plants close to the North Sea with CO{sub 2} capture and the utilisation of the CO{sub 2} for EOR in the North Sea. DONG Energy's perspective is that CO{sub 2} for EOR can contribute to materialising the vision that the central power plant can be developed into an energy refinery. The development work presented will be carried out in cooperation with leading international players and Danish universities and knowledge centres Technical University of Denmark (DTU), The Danish Geotechnical Institute (GEO) and Geological

Is CP violation maximal

International Nuclear Information System (INIS)

Gronau, M.

1984-01-01

Two ambiguities are noted in the definition of the concept of maximal CP violation. The phase convention ambiguity is overcome by introducing a CP violating phase in the quark mixing matrix U which is invariant under rephasing transformations. The second ambiguity, related to the parametrization of U, is resolved by finding a single empirically viable definition of maximal CP violation when assuming that U does not single out one generation. Considerable improvement in the calculation of nonleptonic weak amplitudes is required to test the conjecture of maximal CP violation. 21 references

Neutron Capture Gamma-Ray Spectroscopy. Proceedings of the International Symposium on Neutron Capture Gamma-Ray Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

NONE

1969-11-15

Experimental capabilities in the field of neutron capture gamma-ray spectroscopy have expanded greatly in the last few years; this has been due in large part to the advent of high-quality Ge(Li) detectors, improvements in electronic data processing, and improvements in bent-crystal spectrometers. Previously unsuspected phenomena, such as the '5. 5-MeV1 anomaly, have appeared and new research tools, such as neutron guide tubes, have been brought into use. Equally exciting developments have occurred in the theory of neutron capture. Complex spectra have yielded to analysis after account had been taken of such effects as vibration, rotation and Coriolis forces, and the theoretical prediction of capture spectra seems to be a future possibility. In view of the International Atomic Energy Agency's close interest in this subject and the need for an international exchange of ideas to analyse and study the latest developments, the organizers of the Symposium felt that work on neutron capture gamma-ray spectroscopy had achieved such valuable and significant results that the time had come for this information to be presented, examined and discussed internationally.

Neutron Capture Gamma-Ray Spectroscopy. Proceedings of the International Symposium on Neutron Capture Gamma-Ray Spectroscopy

International Nuclear Information System (INIS)

1969-01-01

Experimental capabilities in the field of neutron capture gamma-ray spectroscopy have expanded greatly in the last few years; this has been due in large part to the advent of high-quality Ge(Li) detectors, improvements in electronic data processing, and improvements in bent-crystal spectrometers. Previously unsuspected phenomena, such as the '5. 5-MeV1 anomaly, have appeared and new research tools, such as neutron guide tubes, have been brought into use. Equally exciting developments have occurred in the theory of neutron capture. Complex spectra have yielded to analysis after account had been taken of such effects as vibration, rotation and Coriolis forces, and the theoretical prediction of capture spectra seems to be a future possibility. In view of the International Atomic Energy Agency's close interest in this subject and the need for an international exchange of ideas to analyse and study the latest developments, the organizers of the Symposium felt that work on neutron capture gamma-ray spectroscopy had achieved such valuable and significant results that the time had come for this information to be presented, examined and discussed internationally

The capture of dark matter particles through the evolution of low-mass stars

International Nuclear Information System (INIS)

Lopes, Ilidio; Casanellas, Jordi; Eugenio, Daniel

2011-01-01

We studied the rate at which stars capture dark matter (DM) particles, considering different assumptions regarding the DM characteristics and, in particular, investigating how the stellar physics influences the capture rate. Two scenarios were considered: first, we assumed the maximal values for the spin-dependent and spin-independent DM particle-nucleon scattering cross sections allowed by the limits from direct detection experiments. Second, we considered that both scattering cross sections are of the same order, with the aim of studying the dependencies of the capture rate on stellar elements other than hydrogen. We found that the characteristics of the capture rate are very different in the two scenarios. Furthermore, we quantified the uncertainties on the computed capture rate (C χ ) and on the ratio between the luminosities from DM annihilations and thermonuclear reactions (L χ /L nuc ) derived from an imprecise knowledge of the stellar structure and DM parameters. For instance, while an uncertainty of 10% on the typical DM velocity leads to similar errors on the computed C χ and L χ /L nuc , the same uncertainty on the stellar mass becomes more relevant and duplicates the errors. Our results may be used to evaluate the reliability of the computed capture rate for the hypothetical use of stars other than the Sun as DM probes.

Shareholder, stakeholder-owner or broad stakeholder maximization

OpenAIRE

Mygind, Niels

2004-01-01

With reference to the discussion about shareholder versus stakeholder maximization it is argued that the normal type of maximization is in fact stakeholder-owner maxi-mization. This means maximization of the sum of the value of the shares and stake-holder benefits belonging to the dominating stakeholder-owner. Maximization of shareholder value is a special case of owner-maximization, and only under quite re-strictive assumptions shareholder maximization is larger or equal to stakeholder-owner...

Energy trading and pricing in microgrids with uncertain energy supply

DEFF Research Database (Denmark)

Ma, Kai; Hu, Shubing; Yang, Jie

2017-01-01

This paper studies an energy trading and pricing problem for microgrids with uncertain energy supply. The energy provider with the renewable energy (RE) generation (wind power) determines the energy purchase from the electricity markets and the pricing strategy for consumers to maximize its profi....... In particular, the uncertainty of the energy supply from the energy provider is considered. Simulation results show that the energy provider can obtain more profit using the proposed decision-making scheme.......This paper studies an energy trading and pricing problem for microgrids with uncertain energy supply. The energy provider with the renewable energy (RE) generation (wind power) determines the energy purchase from the electricity markets and the pricing strategy for consumers to maximize its profit...

Electron-capture process and ion mobility spectra in plasma chromatography

International Nuclear Information System (INIS)

Karasek, F.W.; Spangler, G.E.

1981-01-01

The basic principles of plasma chromatography are introduced and ion mobility relationships presented. The relationships of plasma chromatography to electron-capture detector mechanisms are discussed, including electron energy considerations and electron-capture reactions. A number of experimental studies by plasma chromatography are described. (C.F.)

Capture, Electron-Cooling and Compression of Antiprotons in a Large Penning-Trap for Physics Experiments with an Ultra-Low Energy Extracted Antiproton Beam

CERN Multimedia

2002-01-01

% PS200 \\\\ \\\\The availability of ultra-low energy antiprotons is a crucial ingredient for the execution of the gravity measurements PS200. We have developed a method to provide such low energy antiprotons based on a large Penning trap (the PS200 catching trap). This system can accept a fast-extracted pulse from LEAR, reduce the energy of the antiprotons in the pulse from 5.9~MeV to several tens of kilovolts using a degrading foil, and then capture the antiprotons in a large Penning trap. These antiprotons are cooled by electrons previously admitted to the trap and are collected in a small region at the center of the trap. We have demonstrated our capability to capture up to 1~million antiprotons from LEAR in a single shot, electron cool these antiprotons, and transfer up to 95\\% of them into the inner, harmonic region. A storage time in excess of 1 hour was observed. These results have been obtained with the cryogenic trap vacuum coupled to a room temperature vacuum at about l0$ ^- ^{1} ^0 $ Torr, which is an...

Algal Turf Scrubbers: Cleaning Water while Capturing Solar Energy for Bio fuel Production

International Nuclear Information System (INIS)

Jeffrey Bannon, J.; Adey, W.

2010-01-01

Algal Turfs are bio diverse communities of unicellular to filamentous algae of all major algal phyla. Algal Turf Scrubbers (ATS) are bioengineered ecosystems dominated by algal turfs. They clean water to very high quality, and remove CO 2 from the atmosphere by capturing solar energy at rates 10 times that of agriculture and 50 times that of forestry. Since they are controlled ecosystems, using local algae, ATS does not suffer the major disadvantages of agricultural crops, which for maximum efficiency require fertilizers, herbicides and pesticides. ATS removes CO 2 from water and the atmosphere, and can be configured to remove CO 2 from power plant stack gases. As a normal part of operations, ATS removes heavy metals, break down toxic hydrocarbons, and oxygenates treated waters. ATS systems are capable of removing nitrogen and phosphorous from surface waters in the mid latitude US at $0.60/kg and $10.60/kg respectively (10% of the cost certified by the Chesapeake Bay Commission), and independently producing an energy product at $0.85/gallon. Given a nutrient credit system for rewarding nutrient removal from rivers and lakes, this price can be driven down to below $.40/gallon. Conservatively ATS can produce the equivalent of US imported oil on less than 30 M acres of land along major rivers

Effect of fossil fuels on the parameters of CO2 capture.

Science.gov (United States)

Nagy, Tibor; Mizsey, Peter

2013-08-06

The carbon dioxide capture is a more and more important issue in the design and operation of boilers and/or power stations because of increasing environmental considerations. Such processes, absorber desorber should be able to cope with flue gases from the use of different fossil primary energy sources, in order to guarantee a flexible, stable, and secure energy supply operation. The changing flue gases have significant influence on the optimal operation of the capture process, that is, where the required heating of the desorber is the minimal. Therefore special considerations are devoted to the proper design and control of such boiler and/or power stations equipped with CO2 capture process.

Task-oriented maximally entangled states

International Nuclear Information System (INIS)

Agrawal, Pankaj; Pradhan, B

2010-01-01

We introduce the notion of a task-oriented maximally entangled state (TMES). This notion depends on the task for which a quantum state is used as the resource. TMESs are the states that can be used to carry out the task maximally. This concept may be more useful than that of a general maximally entangled state in the case of a multipartite system. We illustrate this idea by giving an operational definition of maximally entangled states on the basis of communication tasks of teleportation and superdense coding. We also give examples and a procedure to obtain such TMESs for n-qubit systems.

Electron capture by highly charged low-velocity ions

International Nuclear Information System (INIS)

Cocke, C.L.; Dubois, R.; Justiniano, E.; Gray, T.J.; Can, C.

1982-01-01

This paper describes the use of a fast heavy ion beam to produce, by bombardment of gaseous targets, highly-charged low-velocity recoil ions, and the use of these secondary ions in turn as projectiles in studies of electron capture and ionization in low-energy collision systems. The interest in collisions involving low-energy highly-charged projectiles comes both from the somewhat simplifying aspects of the physics which attend the long-range capture and from applications to fusion plasmas, astrophysics and more speculative technology such as the production of X-ray lasers. The ions of interest in such applications should have both electronic excitation and center-of-mass energies in the keV range and cannot be produced by simply stripping fast heavy ion beams. Several novel types of ion source have been developed to produce low-energy highly-charged ions, of which the secondary ion recoil source discussed in this paper is one. (Auth.)

Latching and Declutching Control of the Solo Duck Wave-Energy Converter with Different Load Types

Directory of Open Access Journals (Sweden)

Jinming Wu

2017-12-01

Full Text Available The solo duck wave-energy converter (WEC captures power in a point absorber manner, hence it exhibits high power-capture efficiency within only a narrow bandwidth. Passive control is characterized by a unidirectional power flow, and thus its engineering implementation can be simplified. In this paper, two typical passive control strategies, latching and declutching control, are applied to the solo duck WEC to improve its power-capture performance at wave periods larger and smaller than the natural period of the WEC, respectively. Special attention is paid to the peak value of instantaneous WEC performance parameters, including the peak motion excursion, the peak power take-off (PTO moment, and the peak-to-average power ratio, when the captured power is maximized. Performance differences between the linear and coulomb loads are also investigated. Results show that both latching and declutching control can effectively improve captured power, but also incidentally increase the peak motion excursion and peak-to-average power ratio. When under latching and declutching control, the coulomb load leads to the same maximum relative capture width and peak motion excursion as the linear load, but presents smaller peak PTO moment and peak-to-average power ratio than the linear load, hence making the coulomb load the better choice for the solo duck WEC.

Coal and energy security for India: Role of carbon dioxide (CO2) capture and storage (CCS)

International Nuclear Information System (INIS)

Garg, Amit; Shukla, P.R.

2009-01-01

Coal is the abundant domestic energy resource in India and is projected to remain so in future under a business-as-usual scenario. Using domestic coal mitigates national energy security risks. However coal use exacerbates global climate change. Under a strict climate change regime, coal use is projected to decline in future. However this would increase imports of energy sources like natural gas (NG) and nuclear and consequent energy security risks for India. The paper shows that carbon dioxide (CO 2 ) capture and storage (CCS) can mitigate CO 2 emissions from coal-based large point source (LPS) clusters and therefore would play a key role in mitigating both energy security risks for India and global climate change risks. This paper estimates future CO 2 emission projections from LPS in India, identifies the potential CO 2 storage types at aggregate level and matches the two into the future using Asia-Pacific Integrated Model (AIM/Local model) with a Geographical Information System (GIS) interface. The paper argues that clustering LPS that are close to potential storage sites could provide reasonable economic opportunities for CCS in future if storage sites of different types are further explored and found to have adequate capacity. The paper also indicates possible LPS locations to utilize CCS opportunities economically in future, especially since India is projected to add over 220,000 MW of thermal power generation capacity by 2030.

Dual Competing Photovoltaic Supply Chains: A Social Welfare Maximization Perspective

Science.gov (United States)

Su, Shong-Iee Ivan

2017-01-01

In the past decades, the inappropriate subsidy policies in many nations have caused problems such as serious oversupply, fierce competition and subpar social welfare in the photovoltaic (PV) industry in many nations. There is a clear shortage in the PV industry literature regarding how dual supply chains compete and the key decision issues regarding the competition between dual PV supply chains. It is critical to develop effective subsidy policies for the competing PV supply chains to achieve social welfare maximization. This study has explored the dual PV supply chain competition under the Bertrand competition assumption by three game-theoretical modeling scenarios (or supply chain strategies) considering either the public subsidy or no subsidy from a social welfare maximization perspective. A numerical analysis complemented by two sensitivity analyses provides a better understanding of the pricing and quantity decision dynamics in the dual supply chains under three different supply chain strategies and the corresponding outcomes regarding the total supply chain profits, the social welfare and the required total subsidies. The key findings disclose that if there are public subsidies, the dual PV supply chains have the strongest intention to pursue the decentralized strategy to achieve their maximal returns rather than the centralized strategy that would achieve the maximal social welfare; however, the government would need to pay for the maximal subsidy budget. Thus, the best option for the government would be to encourage the dual PV supply chains to adopt a centralized strategy since this will not only maximize the social welfare but also, at the same time, minimize the public subsidy. With a smart subsidy policy, the PV industry can make the best use of the subsidy budget and grow in a sustainable way to support the highly demanded solar power generation in many countries trying very hard to increase the proportion of their clean energy to combat the global

Dual Competing Photovoltaic Supply Chains: A Social Welfare Maximization Perspective

Directory of Open Access Journals (Sweden)

Zhisong Chen

2017-11-01

Full Text Available In the past decades, the inappropriate subsidy policies in many nations have caused problems such as serious oversupply, fierce competition and subpar social welfare in the photovoltaic (PV industry in many nations. There is a clear shortage in the PV industry literature regarding how dual supply chains compete and the key decision issues regarding the competition between dual PV supply chains. It is critical to develop effective subsidy policies for the competing PV supply chains to achieve social welfare maximization. This study has explored the dual PV supply chain competition under the Bertrand competition assumption by three game-theoretical modeling scenarios (or supply chain strategies considering either the public subsidy or no subsidy from a social welfare maximization perspective. A numerical analysis complemented by two sensitivity analyses provides a better understanding of the pricing and quantity decision dynamics in the dual supply chains under three different supply chain strategies and the corresponding outcomes regarding the total supply chain profits, the social welfare and the required total subsidies. The key findings disclose that if there are public subsidies, the dual PV supply chains have the strongest intention to pursue the decentralized strategy to achieve their maximal returns rather than the centralized strategy that would achieve the maximal social welfare; however, the government would need to pay for the maximal subsidy budget. Thus, the best option for the government would be to encourage the dual PV supply chains to adopt a centralized strategy since this will not only maximize the social welfare but also, at the same time, minimize the public subsidy. With a smart subsidy policy, the PV industry can make the best use of the subsidy budget and grow in a sustainable way to support the highly demanded solar power generation in many countries trying very hard to increase the proportion of their clean energy to

Dual Competing Photovoltaic Supply Chains: A Social Welfare Maximization Perspective.

Science.gov (United States)

Chen, Zhisong; Su, Shong-Iee Ivan

2017-11-20

In the past decades, the inappropriate subsidy policies in many nations have caused problems such as serious oversupply, fierce competition and subpar social welfare in the photovoltaic (PV) industry in many nations. There is a clear shortage in the PV industry literature regarding how dual supply chains compete and the key decision issues regarding the competition between dual PV supply chains. It is critical to develop effective subsidy policies for the competing PV supply chains to achieve social welfare maximization. This study has explored the dual PV supply chain competition under the Bertrand competition assumption by three game-theoretical modeling scenarios (or supply chain strategies) considering either the public subsidy or no subsidy from a social welfare maximization perspective. A numerical analysis complemented by two sensitivity analyses provides a better understanding of the pricing and quantity decision dynamics in the dual supply chains under three different supply chain strategies and the corresponding outcomes regarding the total supply chain profits, the social welfare and the required total subsidies. The key findings disclose that if there are public subsidies, the dual PV supply chains have the strongest intention to pursue the decentralized strategy to achieve their maximal returns rather than the centralized strategy that would achieve the maximal social welfare; however, the government would need to pay for the maximal subsidy budget. Thus, the best option for the government would be to encourage the dual PV supply chains to adopt a centralized strategy since this will not only maximize the social welfare but also, at the same time, minimize the public subsidy. With a smart subsidy policy, the PV industry can make the best use of the subsidy budget and grow in a sustainable way to support the highly demanded solar power generation in many countries trying very hard to increase the proportion of their clean energy to combat the global

FLOUTING MAXIMS IN INDONESIA LAWAK KLUB CONVERSATION

Directory of Open Access Journals (Sweden)

Rahmawati Sukmaningrum

2017-04-01

Full Text Available This study aims to identify the types of maxims flouted in the conversation in famous comedy show, Indonesia Lawak Club. Likewise, it also tries to reveal the speakers‘ intention of flouting the maxim in the conversation during the show. The writers use descriptive qualitative method in conducting this research. The data is taken from the dialogue of Indonesia Lawak club and then analyzed based on Grice‘s cooperative principles. The researchers read the dialogue‘s transcripts, identify the maxims, and interpret the data to find the speakers‘ intention for flouting the maxims in the communication. The results show that there are four types of maxims flouted in the dialogue. Those are maxim of quality (23%, maxim of quantity (11%, maxim of manner (31%, and maxim of relevance (35. Flouting the maxims in the conversations is intended to make the speakers feel uncomfortable with the conversation, show arrogances, show disagreement or agreement, and ridicule other speakers.

Spin-polarized electron capture for the Na+3He2+ system at a 3He2+ impact energy of 5.33--9.33 keV/amu

International Nuclear Information System (INIS)

Tanaka, M.; Shimakura, N.; Ohshima, T.; Katori, K.; Fujiwara, M.; Ogata, H.; Kondo, M.

1994-01-01

3 He + atomic polarizations following the spin-polarized electron capture process for the N rvec a(3s)+ 3 He 2+ system were measured at 3 He 2+ impact energies from 5.33 to 9.33 keV/amu. The magnitude of the 3 He + atomic polarizations was deduced from the 3 He + nuclear polarization measured by means of beam-foil spectroscopy. The observed polarization transfer coefficient P T defined by the ratio of the 3 He + atomic polarization to the sodium one showed a pronounced reduction from unity, which was qualitatively explained by the prediction of a simple cascade photon decay model. Evidence for a further reduction of P T from the above model and a possible impact energy dependence of P T suggested an excessive depolarization due to the presence of the collision alignment parameter A 0 col of 3 He + formed by the electron capture process. In order to see this more closely, the observed P T 's were examined theoretically using the semiclassical impact parameter method, in which an 18-state molecular expansion was employed, and atomic-type electron translation effects were rigorously taken into account. Ensuring that both the absolute values and the impact energy dependence of the observed capture cross sections were remarkably well reproduced by the calculations in which the states up to 4f in 3 He + were introduced, it was demonstrated that the calculated results for P T qualitatively reproduced not only the absolute values of the observed P T 's but also their gentle decrease with increasing impact energy. Production of nuclear polarizations resulting from the polarized electron capture processes between multicharged heavy ions and alkaline-earth-metal atoms is an example of one use of the future project of universal polarized heavy-ion sources

Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps

KAUST Repository

Li, Baiyan; Dong, Xinglong; Wang, Hao; Ma, Dingxuan; Tan, Kui; Jensen, Stephanie; Deibert, Benjamin J.; Butler, Joseph; Cure, Jeremy; Shi, Zhan; Thonhauser, Timo; Chabal, Yves J.; Han, Yu; Li, Jing

2017-01-01

capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li

Maximizing recovery of energy and nutrients from urban wastewaters

International Nuclear Information System (INIS)

Selvaratnam, T.; Henkanatte-Gedera, S.M.; Muppaneni, T.; Nirmalakhandan, N.; Deng, S.; Lammers, P.J.

2016-01-01

Historically, UWWs (urban wastewaters) that contain high levels of organic carbon, N (nitrogen), and P (phosphorous) have been considered an environmental burden and have been treated at the expense of significant energy input. With the advent of new pollution abatement technologies, UWWs are now being regarded as a renewable resource from which, useful chemicals and energy could be harvested. This study proposes an integrated, algal-based system that has the potential to treat UWWs to the desired discharge standards in a sustainable manner while recovering high fraction of its energy content as well as its N- and P-contents for use as fertilizers. Key embodiments of the system being proposed are: i) cultivation of an extremophile microalga, Galdieria sulphuraria, in UWW for removal of carbon, N, and P via single-step by mixotrophic metabolism; ii) extraction of energy-rich biocrude and biochar from the cultivated biomass via hydrothermal processing; and, iii) enhancement of biomass productivity via partial recycling of the nutrient-rich AP (aqueous product) from hydrothermal-processed biomass to the cultivation step to optimize productivity, and formulation of fertilizers from the remaining AP. This paper presents a process model to simulate this integrated system, identify the optimal process conditions, and establish ranges for operational parameters. - Highlights: • Developed model for algal system for wastewater treatment/energy production. • Evaluated energy efficiency in algal wastewater treatment/energy production. • Optimized algal wastewater treatment/energy production. • Demonstrated feasibility of energy-positive wastewater treatment.

Amine Solvent Regeneration for CO2 Capture Using Geothermal Energy with Advanced Stripper Configurations

International Nuclear Information System (INIS)

Van Wagener, D.H.; Rochelle, G.T.; Gupta, A.; Bryant, S.L.

2014-01-01

Absorption/stripping using alkanol-amine solvents for removing CO 2 from the flue gas of coal-fired power plants requires a substantial amount of energy. Typical designs anticipate the use of steam extraction between the Intermediate Pressure (IP) and Low Pressure (LP) turbines to provide heat for the re-boiler. Geothermal energy in the form of hot brine offers an alternative to this large parasitic load on the power generation cycle. We investigate the requirements (number and spacing of extraction/injection well pairs) to provide heat at 150 deg. C for a pilot scale (60 MWe) and a full scale (900 MWe) capture process for thirty years. The calculations are based on properties of a geopressured/geothermal aquifer near the Texas Gulf Coast. In the vicinity of a large coal-fired power plant in South Texas, this aquifer lies between 3 050 and 3 350 m (10 000 and 11 000 ft) below the surface. We present a novel design of the stripper/regenerator process based on heat exchange with the brine, discharging the brine at 100 deg. C. The results indicate that the overall process is feasible and that costs are of similar magnitude to standard designs. (authors)

Carbon capture and storage at scale: Lessons from the growth of analogous energy technologies

International Nuclear Information System (INIS)

Rai, Varun; Victor, David G.; Thurber, Mark C.

2010-01-01

At present carbon capture and storage (CCS) is very expensive and its performance is highly uncertain at the scale of commercial power plants. Such challenges to deployment, though, are not new to students of technological change. Several successful technologies, including energy technologies, have faced similar challenges as CCS faces now. To draw lessons for the CCS industry from the history of other energy technologies that, as with CCS today, were risky and expensive early in their commercial development, we have analyzed the development of the US nuclear-power industry, the US SO 2 -scrubber industry, and the global liquefied natural gas (LNG) industry. Through analyzing the development of the analogous industries we arrive at three principal observations. First, government played a decisive role in the development of all of these analogous technologies. Second, diffusion of these technologies beyond the early demonstration and niche projects hinged on the credibility of incentives for industry to invest in commercial-scale projects. Third, the conventional wisdom that experience with technologies inevitably reduces costs does not necessarily hold. Risky and capital-intensive technologies may be particularly vulnerable to diffusion without accompanying reductions in cost.

Carbon capture and storage at scale. Lessons from the growth of analogous energy technologies

Energy Technology Data Exchange (ETDEWEB)

Rai, Varun; Thurber, Mark C. [Program on Energy and Sustainable Development, Stanford University, Stanford, 616 Serra St., Encina Hall, Room E419, CA 94305 (United States); Victor, David G. [School of International Relations and Pacific Studies, University of California, San Diego, La Jolla, CA 92093-0519 (United States)

2010-08-15

At present carbon capture and storage (CCS) is very expensive and its performance is highly uncertain at the scale of commercial power plants. Such challenges to deployment, though, are not new to students of technological change. Several successful technologies, including energy technologies, have faced similar challenges as CCS faces now. To draw lessons for the CCS industry from the history of other energy technologies that, as with CCS today, were risky and expensive early in their commercial development, we have analyzed the development of the US nuclear-power industry, the US SO{sub 2}-scrubber industry, and the global liquefied natural gas (LNG) industry. Through analyzing the development of the analogous industries we arrive at three principal observations. First, government played a decisive role in the development of all of these analogous technologies. Second, diffusion of these technologies beyond the early demonstration and niche projects hinged on the credibility of incentives for industry to invest in commercial-scale projects. Third, the conventional wisdom that experience with technologies inevitably reduces costs does not necessarily hold. Risky and capital-intensive technologies may be particularly vulnerable to diffusion without accompanying reductions in cost. (author)

Carbon capture and storage at scale: Lessons from the growth of analogous energy technologies

Energy Technology Data Exchange (ETDEWEB)

Rai, Varun, E-mail: varun@stanford.ed [Program on Energy and Sustainable Development, Stanford University, Stanford, 616 Serra St., Encina Hall, Room E419, CA 94305 (United States); Victor, David G. [School of International Relations and Pacific Studies, University of California, San Diego, La Jolla, CA 92093-0519 (United States); Thurber, Mark C. [Program on Energy and Sustainable Development, Stanford University, Stanford, 616 Serra St., Encina Hall, Room E419, CA 94305 (United States)

2010-08-15

At present carbon capture and storage (CCS) is very expensive and its performance is highly uncertain at the scale of commercial power plants. Such challenges to deployment, though, are not new to students of technological change. Several successful technologies, including energy technologies, have faced similar challenges as CCS faces now. To draw lessons for the CCS industry from the history of other energy technologies that, as with CCS today, were risky and expensive early in their commercial development, we have analyzed the development of the US nuclear-power industry, the US SO{sub 2}-scrubber industry, and the global liquefied natural gas (LNG) industry. Through analyzing the development of the analogous industries we arrive at three principal observations. First, government played a decisive role in the development of all of these analogous technologies. Second, diffusion of these technologies beyond the early demonstration and niche projects hinged on the credibility of incentives for industry to invest in commercial-scale projects. Third, the conventional wisdom that experience with technologies inevitably reduces costs does not necessarily hold. Risky and capital-intensive technologies may be particularly vulnerable to diffusion without accompanying reductions in cost.

Theory of inelastic multiphonon scattering and carrier capture by defects in semiconductors: Application to capture cross sections

Science.gov (United States)

Barmparis, Georgios D.; Puzyrev, Yevgeniy S.; Zhang, X.-G.; Pantelides, Sokrates T.

2015-12-01

Inelastic scattering and carrier capture by defects in semiconductors are the primary causes of hot-electron-mediated degradation of power devices, which holds up their commercial development. At the same time, carrier capture is a major issue in the performance of solar cells and light-emitting diodes. A theory of nonradiative (multiphonon) inelastic scattering by defects, however, is nonexistent, while the theory for carrier capture by defects has had a long and arduous history. Here we report the construction of a comprehensive theory of inelastic scattering by defects, with carrier capture being a special case. We distinguish between capture under thermal equilibrium conditions and capture under nonequilibrium conditions, e.g., in the presence of an electrical current or hot carriers where carriers undergo scattering by defects and are described by a mean free path. In the thermal-equilibrium case, capture is mediated by a nonadiabatic perturbation Hamiltonian, originally identified by Huang and Rhys and by Kubo, which is equal to linear electron-phonon coupling to first order. In the nonequilibrium case, we demonstrate that the primary capture mechanism is within the Born-Oppenheimer approximation (adiabatic transitions), with coupling to the defect potential inducing Franck-Condon electronic transitions, followed by multiphonon dissipation of the transition energy, while the nonadiabatic terms are of secondary importance (they scale with the inverse of the mass of typical atoms in the defect complex). We report first-principles density-functional-theory calculations of the capture cross section for a prototype defect using the projector-augmented wave, which allows us to employ all-electron wave functions. We adopt a Monte Carlo scheme to sample multiphonon configurations and obtain converged results. The theory and the results represent a foundation upon which to build engineering-level models for hot-electron degradation of power devices and the performance

VIOLATION OF CONVERSATION MAXIM ON TV ADVERTISEMENTS

Directory of Open Access Journals (Sweden)

Desak Putu Eka Pratiwi

2015-07-01

Full Text Available Maxim is a principle that must be obeyed by all participants textually and interpersonally in order to have a smooth communication process. Conversation maxim is divided into four namely maxim of quality, maxim of quantity, maxim of relevance, and maxim of manner of speaking. Violation of the maxim may occur in a conversation in which the information the speaker has is not delivered well to his speaking partner. Violation of the maxim in a conversation will result in an awkward impression. The example of violation is the given information that is redundant, untrue, irrelevant, or convoluted. Advertisers often deliberately violate the maxim to create unique and controversial advertisements. This study aims to examine the violation of maxims in conversations of TV ads. The source of data in this research is food advertisements aired on TV media. Documentation and observation methods are applied to obtain qualitative data. The theory used in this study is a maxim theory proposed by Grice (1975. The results of the data analysis are presented with informal method. The results of this study show an interesting fact that the violation of maxim in a conversation found in the advertisement exactly makes the advertisements very attractive and have a high value.

Finding Maximal Quasiperiodicities in Strings

DEFF Research Database (Denmark)

Brodal, Gerth Stølting; Pedersen, Christian N. S.

2000-01-01

of length n in time O(n log n) and space O(n). Our algorithm uses the suffix tree as the fundamental data structure combined with efficient methods for merging and performing multiple searches in search trees. Besides finding all maximal quasiperiodic substrings, our algorithm also marks the nodes......Apostolico and Ehrenfeucht defined the notion of a maximal quasiperiodic substring and gave an algorithm that finds all maximal quasiperiodic substrings in a string of length n in time O(n log2 n). In this paper we give an algorithm that finds all maximal quasiperiodic substrings in a string...... in the suffix tree that have a superprimitive path-label....

The Effects of Hypobaric Hypoxia on Erythropoiesis, Maximal Oxygen Uptake and Energy Cost of Exercise Under Normoxia in Elite Biathletes

Directory of Open Access Journals (Sweden)

Milosz Czuba

2014-12-01

Full Text Available The aim of the present study was to evaluate the effects of 3 weeks altitude training according to the HiHiLo (live high-base train high-interval train low procedure as described by Chapman et al. (1998, on erythropoiesis, maximal oxygen uptake and energy cost of exercise under normoxia in elite biathletes. Fifteen male elite biathletes randomly divided into an experimental (H group (n = 7; age 27.1 ± 4.6 years; maximal oxygen uptake (VO2max 66.9 ± 3.3 ml·kg–1·min–1; body height (BH 1.81 ± 0.06 m; body mass (BM 73.1 ± 5.4kg, and a control (C group (n = 8; age 23.2 ± 0.9 years; VO2max 68.2 ± 4.1 ml·kg–1·min–1; BH 1.75 ± 0.03 m; BM 63.1 ± 1.5 kg took part in the study. The H group stayed for 3 weeks at an altitude of 2015 m and performed endurance training on skis four times per week at 3000 m. Additionally, the training protocol included three high-intensity interval sessions at an altitude of 1000 m. The C group followed the same training protocol with skirollers in normoxia at an altitude of 600 m. The HiHiLo protocol applied in our study did not change VO2max or maximal workload (WRmax significantly during the incremental treadmill test in group H. However, the energy cost for selected submaximal workloads in group H was significantly (p < 0.01 reduced compared to group C (-5.7%, -4.4%, -6% vs. -3.5%, -2.1%, -2.4%. Also a significant (p < 0.001 increase in serum EPO levels during the first two weeks of HiHiLo training at 2015 m was observed, associated with a significant (p < 0.05 increase in hemoglobin mass, number of erythrocytes, hematocrit value and percent of reticulocytes compared with initial values (by 6.4%, 5%, 4.6% and 16,6%, respectively. In group C, changes in these variables were not observed. These positive changes observed in our study led to a conclusion that the HiHiLo training method could improve endurance in normoxia, since most of the biathlon competitions are performed at submaximal intensities.

A Game Theoretic Approach for Balancing Energy Consumption in Clustered Wireless Sensor Networks.

Science.gov (United States)

Yang, Liu; Lu, Yinzhi; Xiong, Lian; Tao, Yang; Zhong, Yuanchang

2017-11-17

Clustering is an effective topology control method in wireless sensor networks (WSNs), since it can enhance the network lifetime and scalability. To prolong the network lifetime in clustered WSNs, an efficient cluster head (CH) optimization policy is essential to distribute the energy among sensor nodes. Recently, game theory has been introduced to model clustering. Each sensor node is considered as a rational and selfish player which will play a clustering game with an equilibrium strategy. Then it decides whether to act as the CH according to this strategy for a tradeoff between providing required services and energy conservation. However, how to get the equilibrium strategy while maximizing the payoff of sensor nodes has rarely been addressed to date. In this paper, we present a game theoretic approach for balancing energy consumption in clustered WSNs. With our novel payoff function, realistic sensor behaviors can be captured well. The energy heterogeneity of nodes is considered by incorporating a penalty mechanism in the payoff function, so the nodes with more energy will compete for CHs more actively. We have obtained the Nash equilibrium (NE) strategy of the clustering game through convex optimization. Specifically, each sensor node can achieve its own maximal payoff when it makes the decision according to this strategy. Through plenty of simulations, our proposed game theoretic clustering is proved to have a good energy balancing performance and consequently the network lifetime is greatly enhanced.

State-selective electron capture

International Nuclear Information System (INIS)

Dunford, R.W.; Liu, C.J.; Berry, H.G.; Pardo, R.C.; Raphaelian, M.L.A.

1988-01-01

We report results from a new atomic physics program using the Argonne PII ECR ion source which is being built as part of the upgrade of the Argonne Tandem-Linear Accelerator (ATLAS). Our initial experiments have been aimed at studying state-selective electron capture in ion-atom collisions using the technique of Photon Emission Spectroscopy. We are extending existing cross section measurements at low energy ( 6+ and O 7+ on He and H 2 targets in the energy range from 1-105 keV/amu. We also present uv spectra obtained in collisions of O 6+ , O 5+ and N 5+ on a sodium target. 4 refs., 2 figs., 1 tab

Deliberative decarbonisation? Assessing the potential of an ethical governance framework for low-carbon energy through the case of carbon dioxide capture and storage

OpenAIRE

Leslie Mabon; Simon Shackley; Samuela Vercelli; Jonathan Anderlucci; Kelvin Boot

2015-01-01

In this paper we explore the potential of a framework of ethical governance for low-carbon energy. Developing mainly in the field of information and communications technology, ethical governance is concerned with the marginalisation of ethical and moral issues during development and deployment of new technologies. Focusing on early carbon dioxide capture and storage (CCS) projects, we argue that a focus on technical arguments in the governance of low-carbon energy similarly risks sidelining d...

A Life Cycle Assessment Case Study of Coal-Fired Electricity Generation with Humidity Swing Direct Air Capture of CO2 versus MEA-Based Postcombustion Capture.

Science.gov (United States)

van der Giesen, Coen; Meinrenken, Christoph J; Kleijn, René; Sprecher, Benjamin; Lackner, Klaus S; Kramer, Gert Jan

2017-01-17

Most carbon capture and storage (CCS) envisions capturing CO 2 from flue gas. Direct air capture (DAC) of CO 2 has hitherto been deemed unviable because of the higher energy associated with capture at low atmospheric concentrations. We present a Life Cycle Assessment of coal-fired electricity generation that compares monoethanolamine (MEA)-based postcombustion capture (PCC) of CO 2 with distributed, humidity-swing-based direct air capture (HS-DAC). Given suitable temperature, humidity, wind, and water availability, HS-DAC can be largely passive. Comparing energy requirements of HS-DAC and MEA-PCC, we find that the parasitic load of HS-DAC is less than twice that of MEA-PCC (60-72 kJ/mol versus 33-46 kJ/mol, respectively). We also compare other environmental impacts as a function of net greenhouse gas (GHG) mitigation: To achieve the same 73% mitigation as MEA-PCC, HS-DAC would increase nine other environmental impacts by on average 38%, whereas MEA-PCC would increase them by 31%. Powering distributed HS-DAC with photovoltaics (instead of coal) while including recapture of all background GHG, reduces this increase to 18%, hypothetically enabling coal-based electricity with net-zero life-cycle GHG. We conclude that, in suitable geographies, HS-DAC can complement MEA-PCC to enable CO 2 capture independent of time and location of emissions and recapture background GHG from fossil-based electricity beyond flue stack emissions.

New Maxwellian averaged neutron capture cross sections for 35,37Cl

International Nuclear Information System (INIS)

Guber, K.H.; Sayer, R.O.; Valentine, T.E.; Leal, L.C.; Spencer, R.R.; Harvey, J.A.; Koehler, P.E.; Rauscher, T.

2002-01-01

The Oak Ridge Electron Linear Accelerator (ORELA) was used to measure neutron total and capture cross sections of natural chlorine in the energy range from 100 eV to 600 keV. We performed an R-matrix analysis of our new capture and transmission data up to 500 keV. From these resonance parameters new (n,γ) astrophysical reaction rates were determined over the entire energy range needed by the latest stellar models of the s process

Shareholder, stakeholder-owner or broad stakeholder maximization

DEFF Research Database (Denmark)

Mygind, Niels

2004-01-01

With reference to the discussion about shareholder versus stakeholder maximization it is argued that the normal type of maximization is in fact stakeholder-owner maxi-mization. This means maximization of the sum of the value of the shares and stake-holder benefits belonging to the dominating...... including the shareholders of a company. Although it may be the ultimate goal for Corporate Social Responsibility to achieve this kind of maximization, broad stakeholder maximization is quite difficult to give a precise definition. There is no one-dimensional measure to add different stakeholder benefits...... not traded on the mar-ket, and therefore there is no possibility for practical application. Broad stakeholder maximization instead in practical applications becomes satisfying certain stakeholder demands, so that the practical application will be stakeholder-owner maximization un-der constraints defined...

Power-law inter-spike interval distributions infer a conditional maximization of entropy in cortical neurons.

Directory of Open Access Journals (Sweden)

Yasuhiro Tsubo

Full Text Available The brain is considered to use a relatively small amount of energy for its efficient information processing. Under a severe restriction on the energy consumption, the maximization of mutual information (MMI, which is adequate for designing artificial processing machines, may not suit for the brain. The MMI attempts to send information as accurate as possible and this usually requires a sufficient energy supply for establishing clearly discretized communication bands. Here, we derive an alternative hypothesis for neural code from the neuronal activities recorded juxtacellularly in the sensorimotor cortex of behaving rats. Our hypothesis states that in vivo cortical neurons maximize the entropy of neuronal firing under two constraints, one limiting the energy consumption (as assumed previously and one restricting the uncertainty in output spike sequences at given firing rate. Thus, the conditional maximization of firing-rate entropy (CMFE solves a tradeoff between the energy cost and noise in neuronal response. In short, the CMFE sends a rich variety of information through broader communication bands (i.e., widely distributed firing rates at the cost of accuracy. We demonstrate that the CMFE is reflected in the long-tailed, typically power law, distributions of inter-spike intervals obtained for the majority of recorded neurons. In other words, the power-law tails are more consistent with the CMFE rather than the MMI. Thus, we propose the mathematical principle by which cortical neurons may represent information about synaptic input into their output spike trains.

On the maximal superalgebras of supersymmetric backgrounds

International Nuclear Information System (INIS)

Figueroa-O'Farrill, Jose; Hackett-Jones, Emily; Moutsopoulos, George; Simon, Joan

2009-01-01

In this paper we give a precise definition of the notion of a maximal superalgebra of certain types of supersymmetric supergravity backgrounds, including the Freund-Rubin backgrounds, and propose a geometric construction extending the well-known construction of its Killing superalgebra. We determine the structure of maximal Lie superalgebras and show that there is a finite number of isomorphism classes, all related via contractions from an orthosymplectic Lie superalgebra. We use the structure theory to show that maximally supersymmetric waves do not possess such a maximal superalgebra, but that the maximally supersymmetric Freund-Rubin backgrounds do. We perform the explicit geometric construction of the maximal superalgebra of AdS 4 X S 7 and find that it is isomorphic to osp(1|32). We propose an algebraic construction of the maximal superalgebra of any background asymptotic to AdS 4 X S 7 and we test this proposal by computing the maximal superalgebra of the M2-brane in its two maximally supersymmetric limits, finding agreement.

Evaluation of Maxim Module-Integrated Electronics at the DOE Regional Test Centers: Preprint

Energy Technology Data Exchange (ETDEWEB)

Deline, C.; Sekulic, B.; Stein, J.; Barkaszi, S.; Yang, J.; Kahn, S.

2014-07-01

Module-embedded power electronics developed by Maxim Integrated are under evaluation through a partnership with the Department of Energy's Regional Test Center (RTC) program. Field deployments of both conventional modules and electronics-enhanced modules are designed to quantify the performance advantage of Maxim's products under different amounts of inter-row shading, and their ability to be deployed at a greater ground-coverage-ratio than conventional modules. Simulations in PVSYST have quantified the predicted performance difference between conventional modules and Maxim's modules from inter-row shading. Initial performance results have identified diffuse irradiance losses at tighter row spacing for both the Maxim and conventional modules. Comparisons with published models show good agreement with models predicting the greatest diffuse irradiance losses. At tighter row spacing, all of the strings equipped with embedded power electronics outperformed their conventional peers. An even greater performance advantage is predicted to occur in the winter months when the amount of inter-row shading mismatch is at a maximum.

Gadolinium neutron capture therapy

International Nuclear Information System (INIS)

Akine, Yasuyuki; Tokita, Nobuhiko; Tokuuye, Koichi; Satoh, Michinao; Churei, Hisahiko

1993-01-01

Gadolinium neutron capture therapy makes use of photons and electrons produced by nuclear reactions between gadolinium and lower-energy neutrons which occur within the tumor. The results of our studies have shown that its radiation effect is mostly of low LET and that the electrons are the significant component in the over-all dose. The dose from gadolinium neutron capture reactions does not seem to increase in proportion to the gadolinium concentration, and the Gd-157 concentration of about 100 μg/ml appears most optimal for therapy. Close contact between gadolinium and the cell is not necessarily required for cell inactivation, however, the effect of electrons released from intracellular gadolinium may be significant. Experimental studies on tumor-bearing mice and rabbits have shown that this is a very promising modality though further improvements in gadolinium delivery to tumors are needed. (author)

Preclinical studies on gadolinium neutron capture therapy

International Nuclear Information System (INIS)

Akine, Yasuyuki

1994-01-01

Gadolinium neutron capture therapy is based on radiations (photons and electrons) produced in the tumor by a nuclear reaction between gadolinium and lower-energy neutrons. Studies with Chinese hamster cells have shown that the radiation effect resulting from gadolinium neutron capture reactions is mostly of low LET and that released electrons are the significant component in the over-all dose. Biological dosimetry revealed that the dose does not seem to increase in proportion to the gadolinium concentration, leading to a conclusion that there is a range of gadolinium concentrations most efficient for gadolinium neutron capture therapy. The in vivo studies with transplantable tumors in mice and rabbits have revealed that close contact between gadolinium and the cell is not necessarily required for cell inactivation and that gadolinium delivery selective to tumors is crucial. The results show that the potential of gadolinium neutron capture therapy as a therapeutic modality appears very promising. (author)

Field Testing of Cryogenic Carbon Capture

Energy Technology Data Exchange (ETDEWEB)

Sayre, Aaron [Sustainable Energy Solutions, LLC; Frankman, Dave [Sustainable Energy Solutions, LLC; Baxter, Andrew [Sustainable Energy Solutions, LLC; Stitt, Kyler [Sustainable Energy Solutions, LLC; Baxter, Larry [Sustainable Energy Solutions, LLC; Brigham Young Univ., Provo, UT (United States)

2017-07-17

Sustainable Energy Solutions has been developing Cryogenic Carbon Capture™ (CCC) since 2008. In that time two processes have been developed, the External Cooling Loop and Compressed Flue Gas Cryogenic Carbon Capture processes (CCC ECL™ and CCC CFG™ respectively). The CCC ECL™ process has been scaled up to a 1TPD CO2 system. In this process the flue gas is cooled by an external refrigerant loop. SES has tested CCC ECL™ on real flue gas slip streams from subbituminous coal, bituminous coal, biomass, natural gas, shredded tires, and municipal waste fuels at field sites that include utility power stations, heating plants, cement kilns, and pilot-scale research reactors. The CO2 concentrations from these tests ranged from 5 to 22% on a dry basis. CO2 capture ranged from 95-99+% during these tests. Several other condensable species were also captured including NO2, SO2 and PMxx at 95+%. NO was also captured at a modest rate. The CCC CFG™ process has been scaled up to a .25 ton per day system. This system has been tested on real flue gas streams including subbituminous coal, bituminous coal and natural gas at field sites that include utility power stations, heating plants, and pilot-scale research reactors. CO2 concentrations for these tests ranged from 5 to 15% on a dry basis. CO2 capture ranged from 95-99+% during these tests. Several other condensable species were also captured including NO2, SO2 and PMxx at 95+%. NO was also captured at 90+%. Hg capture was also verified and the resulting effluent from CCC CFG™ was below a 1ppt concentration. This paper will focus on discussion of the capabilities of CCC, the results of field testing and the future steps surrounding the development of this technology.

Electron capture in collisions of S4+ with helium

International Nuclear Information System (INIS)

Wang, J.G.; Stancil, P.C.; Turner, A.R.; Cooper, D.L.; Schultz, D.R.; Rakovic, M.J.; Fritsch, W.; Zygelman, B.

2002-01-01

Charge transfer due to collisions of ground-state S 4+ (3s 2 1 S) ions with helium is investigated for energies between 0.1 meV u -1 and 10 MeV u -1 . Total and state-selective single electron capture (SEC) cross sections and rate coefficients are obtained utilizing the quantum mechanical molecular-orbital close-coupling (MOCC), atomic-orbital close-coupling (AOCC), classical trajectory Monte Carlo (CTMC) and continuum distorted wave methods. The MOCC calculations utilize ab initio adiabatic potentials and nonadiabatic radial coupling matrix elements obtained with the spin-coupled valence-bond approach. Previous data are limited to a calculation of the total SEC rate coefficient using the Landau-Zener model that is, in comparison to the results presented here, three orders of magnitude smaller. The MOCC SEC cross sections at low energy reveal a multichannel interference effect. True double capture is also investigated with the AOCC and CTMC approaches while autoionizing double capture and transfer ionization (TI) is explored with CTMC. SEC is found to be the dominant process except for E>200 keV u -1 when TI becomes the primary capture channel. Astrophysical implications are briefly discussed. (author)

Electron capture in collisions of S4+ with helium

Science.gov (United States)

Wang, J. G.; Turner, A. R.; Cooper, D. L.; Schultz, D. R.; Rakovic, M. J.; Fritsch, W.; Stancil, P. C.; Zygelman, B.

2002-07-01

Charge transfer due to collisions of ground-state S4+(3s2 1S) ions with helium is investigated for energies between 0.1 meV u-1 and 10 MeV u-1. Total and state-selective single electron capture (SEC) cross sections and rate coefficients are obtained utilizing the quantum mechanical molecular-orbital close-coupling (MOCC), atomic-orbital close-coupling (AOCC), classical trajectory Monte Carlo (CTMC) and continuum distorted wave methods. The MOCC calculations utilize ab initio adiabatic potentials and nonadiabatic radial coupling matrix elements obtained with the spin-coupled valence-bond approach. Previous data are limited to a calculation of the total SEC rate coefficient using the Landau-Zener model that is, in comparison to the results presented here, three orders of magnitude smaller. The MOCC SEC cross sections at low energy reveal a multichannel interference effect. True double capture is also investigated with the AOCC and CTMC approaches while autoionizing double capture and transfer ionization (TI) is explored with CTMC. SEC is found to be the dominant process except for E>200 keV u-1 when TI becomes the primary capture channel. Astrophysical implications are briefly discussed.

Ab initio Thermodynamic Approach to Identify Mixed Solid Sorbents for CO2 Capture Technology

Directory of Open Access Journals (Sweden)

Yuhua eDuan

2015-10-01

Full Text Available Because the current technologies for capturing CO2 are still too energy intensive, new materials must be developed that can capture CO2 reversibly with acceptable energy costs. At a given CO2 pressure, the turnover temperature (Tt of the reaction of an individual solid that can capture CO2 is fixed. Such Tt may be outside the operating temperature range (ΔTo for a practical capture technology. To adjust Tt to fit the practical ΔTo, in this study, three scenarios of mixing schemes are explored by combining thermodynamic database mining with first principles density functional theory and phonon lattice dynamics calculations. Our calculated results demonstrate that by mixing different types of solids, it’s possible to shift Tt to the range of practical operating temperature conditions. According to the requirements imposed by the pre- and post- combustion technologies and based on our calculated thermodynamic properties for the CO2 capture reactions by the mixed solids of interest, we were able to identify the mixing ratios of two or more solids to form new sorbent materials for which lower capture energy costs are expected at the desired pressure and temperature conditions.

Maximal locality and predictive power in higher-dimensional, compactified field theories

International Nuclear Information System (INIS)

Kubo, Jisuke; Nunami, Masanori

2004-01-01

To realize maximal locality in a trivial field theory, we maximize the ultraviolet cutoff of the theory by fine tuning the infrared values of the parameters. This optimization procedure is applied to the scalar theory in D + 1 dimensional (D ≥ 4) with one extra dimension compactified on a circle of radius R. The optimized, infrared values of the parameters are then compared with the corresponding ones of the uncompactified theory in D dimensions, which is assumed to be the low-energy effective theory. We find that these values approximately agree with each other as long as R -1 > approx sM is satisfied, where s ≅ 10, 50, 50, 100 for D = 4,5,6,7, and M is a typical scale of the D-dimensional theory. This result supports the previously made claim that the maximization of the ultraviolet cutoff in a nonrenormalizable field theory can give the theory more predictive power. (author)

Energy-efficient power allocation of two-hop cooperative systems with imperfect channel estimation

KAUST Repository

Amin, Osama

2015-06-08

Recently, much attention has been paid to the green design of wireless communication systems using energy efficiency (EE) metrics that should capture all energy consumption sources to deliver the required data. In this paper, we formulate an accurate EE metric for cooperative two-hop systems that use the amplify-and-forward relaying scheme. Different from the existing research that assumes the availability of perfect channel state information (CSI) at the communication cooperative nodes, we assume a practical scenario, where training pilots are used to estimate the channels. The estimated CSI can be used to adapt the available resources of the proposed system in order to maximize the EE. Two estimation strategies are assumed namely disintegrated channel estimation, which assumes the availability of channel estimator at the relay, and cascaded channel estimation, where the relay is not equipped with channel estimator and only forwards the received pilot(s) in order to let the destination estimate the cooperative link. The channel estimation cost is reflected on the EE metric by including the estimation error in the signal-to-noise term and considering the energy consumption during the estimation phase. Based on the formulated EE metric, we propose an energy-aware power allocation algorithm to maximize the EE of the cooperative system with channel estimation. Furthermore, we study the impact of the estimation parameters on the optimized EE performance via simulation examples.

Capturing of staphylococcus aureus onto an interface containing graft chains

International Nuclear Information System (INIS)

Lee, W.; Furusaki, Shintaro; Saito, Kyoichi; Sugo, Takanobu; Makuuchi, Keizo.

1995-01-01

A microbial-cell-capturing material was prepared by radiation-induced grafting of glycidyl methacrylate onto a polyethylene-based fiber before the introduction of diethylamine. The prepared fiber was tested against a Staphylococcus aureus and Escherichia coli solution. The results showed that the grafted-type fiber had a capturing rate constant 1000-fold higher than the commercial crosslinked-type bead for S. aureus and that an activation energy of 39 kJ/mol was obtained for the microbial-cell-capturing action. (author)

Hydrogen production by reforming of fossil and biomass fuels accompanied by carbon dioxide capture process is the energy source for the near future

International Nuclear Information System (INIS)

Aboudheir, Ahmed; Idem, Raphael; Tontiwachwuthikul, Paitoon; Wilson, Malcolm; Kambietz, Lionel

2006-01-01

Hydrogen has a significant future potential as an alternative energy source for the transportation sector as well as in residential homes and offices, H 2 in fuel cell power systems provides an alternative to direct fossil fuel and biomass combustion based technologies and offer the possibility for a significant reduction in greenhouse gas emission based on improved H 2 yield per unit of fossil fuel and biomass, compatibility with renewable energies and motivation to convert to a H 2 -based energy economy. Several practical techniques for H 2 production to service H 2 refuelling stations as well as homes and offices, all of which need to be located at the end of the energy distribution network, include: (1) the carbon dioxide reforming of natural gas; (2) reforming of gasoline; (3) reforming of crude ethanol. Locating the H 2 production at the end of the energy distribution network solves the well-known problems of metal fatigue and high cost of H 2 compression for long distance transportation if H 2 is produced in a large centralized plant. In addition, the ratification of the Kyoto Protocol and the need to reduce emissions of CO 2 to the atmosphere has prompted the capture and utilization of the CO 2 produced from the reforming process. In this research: (1) new efficient catalysts for each reforming process was developed; (2) a new efficient catalyst for our version of the water gas shift reaction to convert carbon monoxide to carbon dioxide was developed; (3) a new membrane separation process for production of high purity, fuel cell-grade H 2 was designed; (4) a numerical model for optimum process design and optimum utilization of resources both at the laboratory and industrial scales was developed; (5) various processes for CO 2 capture were investigated experimentally in order to achieve a net improvement in the absorption process; (6) the utilization of captured CO 2 for enhanced oil recovery and/or storage in an aging oil field were investigated; (7

Maximally multipartite entangled states

Science.gov (United States)

Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio

2008-06-01

We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.

Maximally Symmetric Composite Higgs Models.

Science.gov (United States)

Csáki, Csaba; Ma, Teng; Shu, Jing

2017-09-29

Maximal symmetry is a novel tool for composite pseudo Goldstone boson Higgs models: it is a remnant of an enhanced global symmetry of the composite fermion sector involving a twisting with the Higgs field. Maximal symmetry has far-reaching consequences: it ensures that the Higgs potential is finite and fully calculable, and also minimizes the tuning. We present a detailed analysis of the maximally symmetric SO(5)/SO(4) model and comment on its observational consequences.

Carbon Capture and Storage and Carbon Capture and Utilization: What Do They Offer to Indonesia?

Energy Technology Data Exchange (ETDEWEB)

Adisaputro, Didi, E-mail: didiadisaputro@gmail.com [Department of Chemical and Biological Engineering, University of Sheffield, Sheffield (United Kingdom); Department of Energy Security, Indonesian Defence University, Bogor (Indonesia); Saputra, Bastian [Department of Chemical and Biological Engineering, University of Sheffield, Sheffield (United Kingdom)

2017-03-30

Indonesia is a developing country with abundance resource of fossil fuel in the world, and this fossil fuel will remain as the main source of energy over the next few decades. However, the Indonesian Government has committed to reducing greenhouse gas emissions from fossil fuel consumption as an effort to mitigate climate change. In view of this, two possible energy scenarios are envisioned to honor this commitment: “business as usual” (BaU) and the National Energy Policy (NEP) scenario (National Energy Council, 2014). The NEP scenario reduces CO{sub 2} emissions by up to 26% through an improved energy mix, less reliance on carbon-based fuels, and the deployment of renewable energy sources from 2020 to 2050. However, these actions are considered insufficient to further reduce the CO{sub 2} emission target, leading to an initiative to implement carbon capture and storage (CCS) technology.

Gas permeation process for post combustion CO2 capture

International Nuclear Information System (INIS)

Pfister, Marc

2017-01-01

CO 2 Capture and Storage (CCS) is a promising solution to separate CO 2 from flue gas, to reduce the CO 2 emissions in the atmosphere, and hence to reduce global warming. In CCS, one important constraint is the high additional energy requirement of the different capture processes. That statement is partly explained by the low CO 2 fraction in the inlet flue gas and the high output targets in terms of CO 2 capture and purity (≥90%). Gas permeation across dense membrane can be used in post combustion CO 2 capture. Gas permeation in a dense membrane is ruled by a mass transfer mechanism and separation performance in a dense membrane are characterized by component's effective permeability and selectivity. One of the newest and encouraging type of membrane in terms of separation performance is the facilitated transport membrane. Each particular type of membrane is defined by a specific mass transfer law. The most important difference to the mass transfer behavior in a dense membrane is related to the facilitated transport mechanism and the solution diffusion mechanism and its restrictions and limitations. Permeation flux modelling across a dense membrane is required to perform a post combustion CO 2 capture process simulation. A CO 2 gas permeation separation process is composed of a two-steps membrane process, one drying step and a compression unit. Simulation on the energy requirement and surface area of the different membrane modules in the global system are useful to determine the benefits of using dense membranes in a post combustion CO 2 capture technology. (author)

Room-temperature ionic liquids and composite materials: platform technologies for CO(2) capture.

Science.gov (United States)

Bara, Jason E; Camper, Dean E; Gin, Douglas L; Noble, Richard D

2010-01-19

Clean energy production has become one of the most prominent global issues of the early 21st century, prompting social, economic, and scientific debates regarding energy usage, energy sources, and sustainable energy strategies. The reduction of greenhouse gas emissions, specifically carbon dioxide (CO(2)), figures prominently in the discussions on the future of global energy policy. Billions of tons of annual CO(2) emissions are the direct result of fossil fuel combustion to generate electricity. Producing clean energy from abundant sources such as coal will require a massive infrastructure and highly efficient capture technologies to curb CO(2) emissions. Current technologies for CO(2) removal from other gases, such as those used in natural gas sweetening, are also capable of capturing CO(2) from power plant emissions. Aqueous amine processes are found in the vast majority of natural gas sweetening operations in the United States. However, conventional aqueous amine processes are highly energy intensive; their implementation for postcombustion CO(2) capture from power plant emissions would drastically cut plant output and efficiency. Membranes, another technology used in natural gas sweetening, have been proposed as an alternative mechanism for CO(2) capture from flue gas. Although membranes offer a potentially less energy-intensive approach, their development and industrial implementation lags far behind that of amine processes. Thus, to minimize the impact of postcombustion CO(2) capture on the economics of energy production, advances are needed in both of these areas. In this Account, we review our recent research devoted to absorptive processes and membranes. Specifically, we have explored the use of room-temperature ionic liquids (RTILs) in absorptive and membrane technologies for CO(2) capture. RTILs present a highly versatile and tunable platform for the development of new processes and materials aimed at the capture of CO(2) from power plant flue gas and

Carbon Capture and Storage: legal issues

Energy Technology Data Exchange (ETDEWEB)

Mace, M.J.

2006-10-15

Carbon dioxide Capture and Storage (CCS) describes the process of capturing CO2 emissions from industrial and energy-related processes, compressing the gas to a liquid form, transporting it to a storage site (by pipeline, ship, truck or rail), and injecting it into a geological cavity – to isolate it from the atmosphere. CCS has been described as one option in the 'portfolio' of mitigation options - useful as a bridging technology to address the most prevalent greenhouse gases by volume in the short term, while economies make the shift from fossil fuels to low-carbon energy sources, including renewables. The IPCC has estimated that CCS has the potential to contribute 15-55% of the cumulative mitigation effort worldwide until 2100. However, for this to occur, the IPCC estimates that several hundreds or thousands of CO2 capture systems would need to be installed over the next century. Such a prospect raises a host of legal and regulatory issues and concerns. CCS activities will have to be undertaken in a manner consistent with the range of existing regulatory frameworks developed at the national level to address environmental and health and safety risks. But consistency with international law will also be essential where transboundary impacts are possible, transboundary transportation is involved, or offshore storage activities are contemplated.

Plastic scintillation dosimetry for radiation therapy: minimizing capture of Cerenkov radiation noise

International Nuclear Information System (INIS)

Beddar, A Sam; Suchowerska, Natalka; Law, Susan H

2004-01-01

Over the last decade, there has been an increased interest in scintillation dosimetry using small water-equivalent plastic scintillators, because of their favourable characteristics when compared with other more commonly used detector systems. Although plastic scintillators have been shown to have many desirable dosimetric properties, as yet there is no successful commercial detector system of this type available for routine clinical use in radiation oncology. The main factor preventing this new technology from realizing its full potential in commercial applications is the maximization of signal coupling efficiency and the minimization of noise capture. A principal constituent of noise is Cerenkov radiation. This study reports the calculated capture of Cerenkov radiation by an optical fibre in the special case where the radiation is generated by a relativistic particle on the fibre axis and the fibre axis is parallel to the Cerenkov cone. The fraction of radiation captured is calculated as a function of the fibre core refractive index and the refractive index difference between the core and the cladding of the fibre for relativistic particles. This is then used to deduce the relative intensity captured for a range of fibre core refractive indices and fibre core-cladding refractive index differences. It is shown that the core refractive index has little effect on the amount of radiation captured compared to the refractive index difference. The implications of this result for the design of radiation therapy plastic scintillation dosimeters are considered

Production of sustainable methane from renewable energy and captured carbon dioxide with the use of Solid Oxide Electrolyzer: A thermodynamic assessment

International Nuclear Information System (INIS)

Stempien, Jan Pawel; Ni, Meng; Sun, Qiang; Chan, Siew Hwa

2015-01-01

A possible pathway for renewable and sustainable methane production from captured carbon dioxide, water (or seawater) and renewable electricity is proposed and analysed. The proposed system includes Solid Oxide Electrolyzer Cell combined with ex-situ methane synthesis reactor comprising Sabatier, Methanation and Water-Gas Shift reactions. A well validated electrochemical model is used to describe the behaviour of the electrolyzer for steam/carbon dioxide co-electrolysis. The methane synthesis reactor is modelled by a set of equations based on thermodynamic equilibrium reaction constants. Effects of current density, temperature, pressure and initial steam to carbon dioxide ratio on system performance are analysed and their effects are discussed. It is found that a simple, single-pass system without heat recuperation could achieve a maximum overall energy efficiency of 60.87% (based on lower heating value), a maximum electrical energy efficiency of 81.08% (based on lower heating value), and a maximum amount of methane production of ∼1.52 Nm 3  h −1  m −2 of electrolyzer. It is also found that conversion of ∼100% captured carbon dioxide is possible in the proposed system. - Highlights: • Analysis of Solid Oxide Electrolyzer combined with methane synthesis process. • Efficiency of converting water and carbon dioxide into synthetic, renewable methane above 81%. • Effects of process temperature, pressure, gas flux and compositions were analysed. • Methane production of ∼1.52 [Nm 3 h −1 m −2 of electrolyzer]. • Conversion of ∼100% of captured CO 2 is possible

Operating considerations of ultrafiltration in enzyme enhanced carbon capture

DEFF Research Database (Denmark)

Deslauriers, Maria Gundersen; Gladis, Arne; Fosbøl, Philip Loldrup

2017-01-01

capture capacity of 1 MTonn CO2/year, and is here operated for one year continuously. This publication compares soluble enzymes dissolved in a capture solvent with and without the use of ultrafiltration membranes. The membranes used here have an enzyme retention of 90%, 99% and 99.9%. Enzyme retention......Today, enzyme enhanced carbon capture and storage (CCS) is gaining interest, since it can enable the use of energy efficient solvents, and thus potentially reduce the carbon footprint of CCS. However, a limitation of this technology is the high temperatures encountered in the stripper column, which...

Investigations of 1-(4-propylamino-3-ethyl imidazolium tetrafluoroborate ionic liquid capturing CO2

Directory of Open Access Journals (Sweden)

Yang Lijuan

2013-01-01

Full Text Available 1-(4-propylamino-3-ethyl imidazolium ([Paeim]+ Tetrafluoroborate([BF4]- Ionic liquid (IL, capturing CO2, was explored systematically at B3LYP/6-311++G** and mp2/6-311++G** level. The stable geometries of ILs and capture products were optimized, the energies of these geometries were obtained and corrected by Zero-point-vibration-energy and basis set superposition error correction. The results show that the interactions between [Paeim]+and [BF4]-are mainly displayed as hydrogen bonds, but the interaction energies exceeds -328 kJ/mol. Further analysis found that the interactions are reinforced by charge dispersion and charge redistribution of ion-pair, and that electrostatic attraction contributes much to the interaction energies. This IL system capturing CO2belongs to the class of physical sorption with 1:1 molar absorption ratio, the absorption energy is nearly -18kJ/moland thus this IL may have low energy consumption when regenerated from IL-CO2.

Integrated assessment of IGCC power generation technology with carbon capture and storage (CCS)

International Nuclear Information System (INIS)

Cormos, Calin-Cristian

2012-01-01

IGCC (Integrated Gasification Combined Cycle) is a power generation technology in which the solid feedstock is partially oxidized with oxygen and steam to produce syngas. In a conventional IGCC design without carbon capture, the syngas is purified for dust and hydrogen sulphide removal and then it is sent to a CCGT (Combined Cycle Gas Turbine) for power generation. CCS (Carbon capture and storage) technologies are expected to play a significant role in the coming decades for reducing the greenhouse gas emissions. IGCC is one of the power generation technologies having the highest potential to capture CO 2 with low penalties in term of plant energy efficiency, capital and operational costs. This paper investigates the most important techno-economic and environmental indicators (e.g. power output, ancillary consumption, energy efficiency, CW consumption, normalised mass and energy balances and plant construction materials, capital and O and M (operational and maintenance) costs, specific CO 2 emissions, cost of electricity, CO 2 removal and avoidance costs etc.) for IGCC with CCS. Coal-based IGCC cases produce around 400–450 MW net electricity with 90% carbon capture rate. Similar IGCC plants without CCS were presented as references. Future IGCC developments for energy vectors poly-generation were also presented. -- Highlights: ► Techno-economical evaluations of coal-based IGCC power generation with CCS. ► Model development for capital, O and M, CO 2 capture costs and cash flow estimations. ► Technical and economic investigations of key plant design characteristics. ► Evaluations of carbon capture options for IGCC power generation technology.

Maximal quantum Fisher information matrix

International Nuclear Information System (INIS)

Chen, Yu; Yuan, Haidong

2017-01-01

We study the existence of the maximal quantum Fisher information matrix in the multi-parameter quantum estimation, which bounds the ultimate precision limit. We show that when the maximal quantum Fisher information matrix exists, it can be directly obtained from the underlying dynamics. Examples are then provided to demonstrate the usefulness of the maximal quantum Fisher information matrix by deriving various trade-off relations in multi-parameter quantum estimation and obtaining the bounds for the scalings of the precision limit. (paper)

Understanding Violations of Gricean Maxims in Preschoolers and Adults

Directory of Open Access Journals (Sweden)

Mako eOkanda

2015-07-01

Full Text Available This study used a revised Conversational Violations Test to examine Gricean maxim violations in 4- to 6-year-old Japanese children and adults. Participants’ understanding of the following maxims was assessed: be informative (first maxim of quantity, avoid redundancy (second maxim of quantity, be truthful (maxim of quality, be relevant (maxim of relation, avoid ambiguity (second maxim of manner, and be polite (maxim of politeness. Sensitivity to violations of Gricean maxims increased with age: 4-year-olds’ understanding of maxims was near chance, 5-year-olds understood some maxims (first maxim of quantity and maxims of quality, relation, and manner, and 6-year-olds and adults understood all maxims. Preschoolers acquired the maxim of relation first and had the greatest difficulty understanding the second maxim of quantity. Children and adults differed in their comprehension of the maxim of politeness. The development of the pragmatic understanding of Gricean maxims and implications for the construction of developmental tasks from early childhood to adulthood are discussed.

Interpretation of second Born amplitudes in electron capture

International Nuclear Information System (INIS)

McGuire, J.H.; Simony, P.R.; Weaver, O.L.; Macek, J.

1982-01-01

Exact sound Born amplitudes for 1s-1s electron capture are presented and interpreted in terms of contributions from intermediate states off the energy shell and on the energy shell. The classical model of Thomas corresponds to two-step scattering via one particular on-shell intermediate state. In the high-velocity limit for 1s-1s capture, this on-shell intermediate state of the Thomas model accounts for one-half of the total cross section, i.e., the second Born cross section. The other half comes from off-energy-shell intermediate states near the on-shell Thomas state. Above 5 MeV both the off-shell and on-shell amplitudes have a simple structure near the Thomas peak. Below 1 MeV, contributions from a broader range of intermediate states are evident in the amplitudes. Although the contribution from the Thomas state is not large below 1 MeV, other second Born effects are significant

Fast-neutron capture in fissile and fertile nuclides

International Nuclear Information System (INIS)

Peelle, R.W.

1982-01-01

Extensive graphical and numerical presentations, available to the working group, assisted us in exploring the rich data base established through the labors of many skilled persons. Consistent with the meeting setting, the working group discussion concentrated on data for fast-breeder reactor (FBR) applications. All but 1 to 3% of the magnitude of cross section sensitivities of FBR parameters come from the energy region below approx. = 1.5 MeV, so the statistical model is the relevant theoretical concept. The Meeting emphasizes energies above approx. = 10 keV where resonance fluctuations are not a dominant factor. However, we should remember that approximately half the FBR sensitivity to 238 U capture data, as relfected in integral parameters, lies below 25 keV where resonance fluctuations are strong and resonance self-protection is a most important consideration in reactor physics. There are similar low-energy aspects to 239 Pu capture in that approx. = 30% of the FBR-parameter data sensitivity lies below approx. = 4 keV. Even with the discussion largely cofined to the approx. = 10 to 1500 keV region, the working group could only scratch the surface of the available body of information. The reader is referred to the papers presented at the Meeting and to the references contained therein in order to obtain a more detailed understanding of current issues related to fissile and fertile fast-neutron capture

Energy Equivalence of Information in the Mitochondrion and the Thermodynamic Efficiency of ATP Synthase.

Science.gov (United States)

Matta, Chérif F; Massa, Lou

2015-09-01

Half a century ago, Johnson and Knudsen resolved the puzzle of the apparent low efficiency of the kidney (∼ 0.5%) compared to most other bodily organs (∼ 40%) by taking into account the entropic cost of ion sorting, the principal function of this organ. Similarly, it is shown that the efficiency of energy transduction of the chemiosmotic proton-motive force by ATP synthase is closer to 90% instead of the oft-quoted textbook value of only 60% when information theoretic considerations are applied to the mitochondrion. This high efficiency is consistent with the mechanical energy transduction of ATP synthase known to be close to the 100% thermodynamic limit. It would have been wasteful for evolution to maximize the mechanical energy transduction to 100% while wasting 40% of the chemiosmotic free energy in the conversion of the proton-motive force into mechanical work before being captured as chemical energy in adenosine 5'-triphosphate.

Magnetar crust electron capture for {sup 55}Co and {sup 56}Ni

Energy Technology Data Exchange (ETDEWEB)

Liu, Jing-Jing; Liu, Dong-Mei [Hainan Tropical Ocean University, College of Marine Science and Technology, Sanya (China)

2018-01-15

Based on the relativistic mean-field effective interaction principle and random phase approximation theory in superstrong magnetic fields (SMFs), we present an analysis of the influence of SMFs on the electron Fermi energy, nuclear blinding energy, single-particle level structure and electron capture for {sup 55}Co, and {sup 56}Ni by the shell-model Monte Carlo method in the magnetar's crust. The electron capture rates increase by two orders of magnitude due to an increase in the electron Fermi energy and a change in single-particle level structure by SMFs. Then the rates decrease by more than two orders of magnitude due to an increase in the nuclear binding energy and a reduction in the electron Fermi energy by SMFs. (orig.)

Experimental Neutron Capture Rate Constraint Far from Stability.

Science.gov (United States)

Liddick, S N; Spyrou, A; Crider, B P; Naqvi, F; Larsen, A C; Guttormsen, M; Mumpower, M; Surman, R; Perdikakis, G; Bleuel, D L; Couture, A; Crespo Campo, L; Dombos, A C; Lewis, R; Mosby, S; Nikas, S; Prokop, C J; Renstrom, T; Rubio, B; Siem, S; Quinn, S J

2016-06-17

Nuclear reactions where an exotic nucleus captures a neutron are critical for a wide variety of applications, from energy production and national security, to astrophysical processes, and nucleosynthesis. Neutron capture rates are well constrained near stable isotopes where experimental data are available; however, moving far from the valley of stability, uncertainties grow by orders of magnitude. This is due to the complete lack of experimental constraints, as the direct measurement of a neutron-capture reaction on a short-lived nucleus is extremely challenging. Here, we report on the first experimental extraction of a neutron capture reaction rate on ^{69}Ni, a nucleus that is five neutrons away from the last stable isotope of Ni. The implications of this measurement on nucleosynthesis around mass 70 are discussed, and the impact of similar future measurements on the understanding of the origin of the heavy elements in the cosmos is presented.

Bench-Scale Silicone Process for Low-Cost CO{sub 2} Capture

Energy Technology Data Exchange (ETDEWEB)

Wood, Benjamin; Genovese, Sarah; Perry, Robert; Spiry, Irina; Farnum, Rachael; Sing, Surinder; Wilson, Paul; Buckley, Paul; Acharya, Harish; Chen, Wei; McDermott, John; Vipperia, Ravikumar; Yee, Michael; Steele, Ray; Fresia, Megan; Vogt, Kirk

2013-12-31

A bench-scale system was designed and built to test an aminosilicone-based solvent. A model was built of the bench-scale system and this model was scaled up to model the performance of a carbon capture unit, using aminosilicones, for CO{sub 2} capture and sequestration (CCS) for a pulverized coal (PC) boiler at 550 MW. System and economic analysis for the carbon capture unit demonstrates that the aminosilicone solvent has significant advantages relative to a monoethanol amine (MEA)-based system. The CCS energy penalty for MEA is 35.9% and the energy penalty for aminosilicone solvent is 30.4% using a steam temperature of 395 °C (743 °F). If the steam temperature is lowered to 204 °C (400 °F), the energy penalty for the aminosilicone solvent is reduced to 29%. The increase in cost of electricity (COE) over the non-capture case for MEA is ~109% and increase in COE for aminosilicone solvent is ~98 to 103% depending on the solvent cost at a steam temperature of 395 °C (743 °F). If the steam temperature is lowered to 204 °C (400 °F), the increase in COE for the aminosilicone solvent is reduced to ~95-100%.

Technology Roadmaps: Carbon Capture and Storage in Industrial Applications

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

A new technology roadmap on Carbon Capture and Storage in Industrial Applications, released today in Beijing, shows that carbon capture and storage (CCS) has the potential to reduce CO2 emissions from industrial applications by 4 gigatonnes in 2050. Such an amount is equal to roughly one-tenth of the total emission cuts needed from the energy sector by the middle of the century. This requires a rapid deployment of CCS technologies in various industrial sectors, and across both OECD and non-OECD countries. The roadmap, a joint report from the International Energy Agency (IEA) and the United Nations Industrial Development Organization (UNIDO), says that over 1800 industrial-scale projects are required over the next 40 years.

Model independent spectroscopic information from an analysis of peripheral direct radiative capture reaction and its application for an extrapolation of an astrophysical S-factor to stellar energies

International Nuclear Information System (INIS)

Igamov, S.B.; Tursunmuratov, T.M.; Yarmukhamedov, R.

2003-01-01

In this work, within the framework of the cluster potential approach we develop a method which can be used an independent source of getting information on the value of the nuclear vertex constant (NVC) (or respective asymptotical normalization coefficient (ANC)) from the analysis of the direct radiative capture cross section σ(E)(or the astrophysical S-factor S(E)) at extremely low energies by a model independent way as possible. The main idea of the proposed method is that at stellar energies peripheral direct radiative capture reaction of astrophysical interest proceeds mainly through the tail of the overlap integral, which is completely determined by the binding energy and the respective ANC (or NVC). The main advantage of the proposed method is that it allows us to determine both the absolute value of NVC (or ANC) and the astrophysical S-factor S(E) at solar energies (0-50 keV) by means of the analysis of the same experimental astrophysical S-factor S exp (E) in a correct self consistent way using the same potential both for the bound state and for scattering state. The method has been applied for an investigation of the direct radiative capture t(α, γ) 7 Li and 3 He(α, γ) 7 Be reactions at extremely low energies. At first, this method was used for analysis of the S exp (E) to determine values of the modulus squared of the NVC's (or the respective ANC's). The values of NVC's are presented. Then, the obtained NVC's are used by us for extrapolation of the S(E) of the reactions considered to stellar energies (E=0-50 keV) for the 3 He(α, γ) 7 Be reaction and for the t(α, γ) 7 Li reaction. The obtained results are compared with those other authors

An Innovative Configuration for CO2 Capture by High Temperature Fuel Cells

Directory of Open Access Journals (Sweden)

Federico Rossi

2014-09-01

Full Text Available Many technological solutions have been proposed for CO2 capture in the last few years. Most of them are characterized by high costs in terms of energy consumption and, consequently, higher fossil fuel use and higher economic costs. High temperature fuel cells are technological solutions currently developed for energy production with low environmental impact. In CIRIAF—University of Perugia labs, cylindrical geometry, small-sized molten carbonate fuel cell (MCFC prototypes were built and tested with good energy production and lifetime performances. In the present work, an innovative application for MCFCs is proposed, and an innovative configuration for CO2 capture/separation is investigated. The plant scheme is based on a reformer and a cylindrical MCFC. MCFCs are the most suitable solutions, because CO2 is used in their operating cycle. An analysis in terms of energy consumption/kgCO2 captured is made by coupling the proposed configuration with a gas turbine plant. The proposed configuration is characterized by a theoretical energy consumption of about 500 kJ/kgCO2, which is quite lower than actual sequestration technologies. An experimental campaign will be scheduled to verify the theoretical findings.

Differences and implications in biogeochemistry from maximizing entropy production locally versus globally

Directory of Open Access Journals (Sweden)

J. J. Vallino

2011-06-01

Full Text Available In this manuscript we investigate the use of the maximum entropy production (MEP principle for modeling biogeochemical processes that are catalyzed by living systems. Because of novelties introduced by the MEP approach, many questions need to be answered and techniques developed in the application of MEP to describe biological systems that are responsible for energy and mass transformations on a planetary scale. In previous work we introduce the importance of integrating entropy production over time to distinguish abiotic from biotic processes under transient conditions. Here we investigate the ramifications of modeling biological systems involving one or more spatial dimensions. When modeling systems over space, entropy production can be maximized either locally at each point in space asynchronously or globally over the system domain synchronously. We use a simple two-box model inspired by two-layer ocean models to illustrate the differences in local versus global entropy maximization. Synthesis and oxidation of biological structure is modeled using two autocatalytic reactions that account for changes in community kinetics using a single parameter each. Our results show that entropy production can be increased if maximized over the system domain rather than locally, which has important implications regarding how biological systems organize and supports the hypothesis for multiple levels of selection and cooperation in biology for the dissipation of free energy.

Power maximization method for land-transportable fully passive lead–bismuth cooled small modular reactor systems

Energy Technology Data Exchange (ETDEWEB)

Cho, Jaehyun, E-mail: chojh@kaeri.re.kr [Korea Atomic Energy Research Institute, 1405 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Shin, Yong-Hoon; Hwang, Il Soon [Seoul National University, Sillim-dong, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

2015-08-15

Highlights: • The power maximization method for LBE natural circulation cooled SMRs was developed. • The two powers in view of neutronics and thermal-hydraulics were considered. • The limitations for designing of LBE natural circulation cooled SMRs were summarized. • The necessary conditions for safety shutdown in accidents were developed. • The maximized power in the case study is 206 MW thermal. - Abstract: Although current pressurized water reactors (PWRs) have significantly contributed to global energy supply, PWR technology has not been considered a trustworthy energy solution owing to its problems of spent nuclear fuels (SNFs), nuclear safety, and nuclear economy. In order to overcome these problems, a lead–bismuth eutectic (LBE) fully passive cooling small modular reactor (SMR) system is suggested. This technology can not only provide the solution for the problems of SNFs through the transmutation feature of the LBE coolant, but also strengthen safety and economy through the concept of natural circulation cooling SMRs. It is necessary to maximize the advantages, namely safety and economy, of this type of nuclear power plants for broader applications in the future. Accordingly, the objective of this study is to maximize the reactor core power while satisfying the limitations of shipping size, materials endurance, and criticality of a long-burning core as well as safety under beyond design basis events. To achieve these objectives, the design limitations of natural circulating LBE-cooling SMRs are derived. Then, the power maximization method is developed based on obtaining the design limitations. The results of this study are expected to contribute to the effectiveness of the reactor design stage by providing insights to designers, as well as by formulating methods for the power maximization of other types of SMRs.

Neutron radiative capture by the 241Am nucleus in the energy range 1 keV-20 MeV

International Nuclear Information System (INIS)

Zolotarev, K.I.; Ignatyuk, A.V.; Tolstikov, V.A.; Tertychnyj, G.Ya.

1998-01-01

Production of high actinides leads to many technological problems in the nuclear power. The 241 Am(n,γ) 242 Am reaction is one of the sources of high actinide buildup. So a knowledge of the radiative capture cross-section of 241 Am for neutron energies up to 20 MeV is of considerable important for present day fission reactors and future advanced reactors. The main goal of this paper is the evaluation of the excitation function for the reaction 241 Am(n,γ) 242 Am in the energy range 1 keV-20 MeV. The evaluation was done on the basis of analysed experimental data, data from theoretical model calculations and systematic predictions for 14.5 MeV and 20 MeV. Data from the present evaluation are compared with the cross-section values given in the evaluations carried out earlier. (author)

Energy Systems Integration Facility Videos | Energy Systems Integration

Science.gov (United States)

Facility | NREL Energy Systems Integration Facility Videos Energy Systems Integration Facility Integration Facility NREL + SolarCity: Maximizing Solar Power on Electrical Grids Redefining What's Possible for Renewable Energy: Grid Integration Robot-Powered Reliability Testing at NREL's ESIF Microgrid

Experimental determination of neutron capture cross sections of fast reactor structure materials integrated in intermediate energy spectra. Vol. 2: description of experimental structure

International Nuclear Information System (INIS)

Tassan, S.

1978-01-01

A selection of technical documents is given concerning the experimental determination of the neutron capture cross-sections of fast reactor structural materials (Fe, Cr, Ni...) integrated over the intermediate energy spectra. The experimental structure project and modifications of the reactor RB2 for this experiment, together with criticality and safety calculations, are presented

Energy Technology Investments: Maximizing Efficiency Through a Maritime Energy Portfolio Interface and Decision Aid

Science.gov (United States)

2012-02-09

Investment (ROI) and Break Even Point ( BEP ). These metrics are essential for determining whether an initiative would be worth pursuing. Balanced...is Unlimited Energy Decision Framework Identify Inefficiencies 2. Perform Analyses 3. Examine Technology Candidates 1. Improve Energy...Unlimited Energy Decision Framework Identify Inefficiencies 2. Perform Analyses 3. Examine Technology Candidates 1. Improve Energy Efficiency 4

Simultaneous electron capture and excitation in ion-atom collisions

International Nuclear Information System (INIS)

Tanis, J.A.; Bernstein, E.M.; Graham, W.G.; Clark, M.; Shafroth, S.M.; Johnson, B.M.; Jones, K.; Meron, M.

1982-01-01

A review of recent efforts to observe simultaneous electron capture-and-K-shell excitation in ion-atom collisions is presented. This process which has been referred to as resonant-transfer-and-excitation (RTE), is qualitatively analogous to dielectronic recombination (inverse Auger transition) in free-electron-ion collisions, and, hence, is expected to be resonant. Experimentally, events having the correct signature for simultaneous capture-and-excitation are isolated by detecting projectile K x rays in coincidence with ions which capture a single electron. In a recent experiment involving 70-160 MeV S 13+ ions incident on Ar, a maximum was observed in the yield of projectile K x rays associated with electron capture. This maximum is attributed to simultaneous capture - and excitation. The position (120 MeV) and width (60 MeV) of the observed maximum are in good agreement with theoretical calculations. The data indicate that RTE is an important mechanism for inner-shell vacancy production in the energy range studied

Measurements of Pair Production and Electron Capture from the Continuum in Heavy Particle Collisions

CERN Multimedia

2002-01-01

Large transient Coulomb fields, which are generated in collisions of high-Z systems at sufficiently high energies, lead to copious production of electron-positron pairs. It has been suggested that these lepton pairs might mask signals arising from plasma phase interaction. Pair-production cross sections have been calculated by several authors with results which differ significantly from each other. Some of the electrons produced may be captured into bound states of the ion, thereby, reducing its charge state by one unit. This process which has been termed ``Electron Capture from Pair Production``, represents the only electron capture pro which increases with energy, and as such, will dominate all others in the ultrarelativistic energy regime. Ions having undergone this process would be lost from storage-type accelerators. The absolute cross sections for capture have been calculated with results which differ by as much as an order of magnitude. If as large as some of the calculations predict, Relativistic Heav...

Shifts in electron capture to the continuum at low collision energies: Enhanced role of target postcollision interactions

International Nuclear Information System (INIS)

Shah, M. B.; McGrath, C.; Luna, H.; Crothers, D.S.F.; O'Rourke, S.F.C.; Gilbody, H.B.; Illescas, Clara; Riera, A.; Pons, B.

2003-01-01

Measurements of electron velocity distributions emitted at 0 deg. for collisions of 10- and 20-keV H + incident ions on H 2 and He show that the electron capture to the continuum cusp formation, which is still possible at these low impact energies, is shifted to lower momenta than its standard position (centered on the projectile velocity), as recently predicted. Classical trajectory Monte Carlo calculations reproduce the observations remarkably well, and indicate that a long-range residual interaction of the electron with the target ion after ionization is responsible for the shifts, which is a general effect that is enhanced at low nuclear velocities

Recommended data for capture cross sections in B5+ + H collisions

International Nuclear Information System (INIS)

Errea, L F; Guzman, F; Illescas, Clara; Mendez, L; Pons, B; Riera, A; Suarez, J

2006-01-01

Recommended values for state selective capture cross sections are presented for the collision B 5+ + H(1s) in the energy range from 0.05 to 1000 keV amu -1 . Special attention is focused on capture processes to n = 7 states of B 4+ , which play an important role in spectral diagnostics in fusion plasmas. In order to completely cover the intermediate impact energy domain, quantal, semi-classical and classical treatments have been employed for low, low-intermediate and intermediate-high energies, respectively. We also give some guidelines about the domain of accuracy of the methodologies employed. Additionally, preliminary cross sections of the B 5+ + H(2s) collision are also provided

On maximal massive 3D supergravity

OpenAIRE

Bergshoeff , Eric A; Hohm , Olaf; Rosseel , Jan; Townsend , Paul K

2010-01-01

ABSTRACT We construct, at the linearized level, the three-dimensional (3D) N = 4 supersymmetric " general massive supergravity " and the maximally supersymmetric N = 8 " new massive supergravity ". We also construct the maximally supersymmetric linearized N = 7 topologically massive supergravity, although we expect N = 6 to be maximal at the non-linear level. (Bergshoeff, Eric A) (Hohm, Olaf) (Rosseel, Jan) P.K.Townsend@da...

Measurements of neutron capture cross sections of wolfram and thulium

International Nuclear Information System (INIS)

Xia Yijun; Wang Chunhao; Yang Jingfu; Yang Zhihua; Luo Xiaobing

1992-01-01

The neutron capture cross sections of wolfram and thulium were measured in the energy range from 10 to 100 KeV using gold as the standard. Kinematically collimated neutrons were produced via the 7 Li(p, n) 7 Be reaction with a 2.5 MV pulsed Van de Graaff accelerator at Sichuan University. The capture events were detected by a pair of Moxon-Rae detectors. Time-of-flight technique was used to improve the signal-background ratio. The present results are compared with data by other authors. The capture cross section were calculated from 10 to 100 KeV for two nuclides by the Hauser-Feshbach statistical theory with width fluctuation correction. The nonstatistical effects such as potential capture and radiative capture in elastic and inelastic channels of a compound nucleus were included in the calculations. The calculated results show that the nonstatistical contribution to the capture cross sections is negligible compared with that of the statistical effects

Formation of double galaxies by tidal capture

International Nuclear Information System (INIS)

Alladin, S.M.; Potdar, A.; Sastry, K.S.

1975-01-01

The conditions under which double galaxies may be formed by tidal capture are considered. Estimates for the increase in the internal energy of colliding galaxies due to tidal effects are used to determine the magnitudes Vsub(cap) and Vsub(dis) of the maximum relative velocities at infinite separation required for tidal capture and tidal disruption respectively. A double galaxy will be formed by tidal capture without tidal disruption of a component if Vsub(cap)>Vsub(i) and Vsub(cap)>Vsub(dis) where Vsub(i) is the initial relative speed of the two galaxies at infinite separation. If the two galaxies are of the same dimension, formulation of double galaxies by tidal capture is possible in a close collision either if the two galaxies do not differ much in mass and density distribution or if the more massive galaxy is less centrally concentrated than the other. If it is assumed as statistics suggest, that the mass of a galaxy is proportional to the square of its radius, it follows that the probability of the formation of double galaxies by tidal capture increases with the increase in mass of the galaxies and tidal distribution does not occur in a single collision for any distance of closest approach of the two galaxies. (Auth.)

Two-step rapid sulfur capture. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-04-01

The primary goal of this program was to test the technical and economic feasibility of a novel dry sorbent injection process called the Two-Step Rapid Sulfur Capture process for several advanced coal utilization systems. The Two-Step Rapid Sulfur Capture process consists of limestone activation in a high temperature auxiliary burner for short times followed by sorbent quenching in a lower temperature sulfur containing coal combustion gas. The Two-Step Rapid Sulfur Capture process is based on the Non-Equilibrium Sulfur Capture process developed by the Energy Technology Office of Textron Defense Systems (ETO/TDS). Based on the Non-Equilibrium Sulfur Capture studies the range of conditions for optimum sorbent activation were thought to be: activation temperature > 2,200 K for activation times in the range of 10--30 ms. Therefore, the aim of the Two-Step process is to create a very active sorbent (under conditions similar to the bomb reactor) and complete the sulfur reaction under thermodynamically favorable conditions. A flow facility was designed and assembled to simulate the temperature, time, stoichiometry, and sulfur gas concentration prevalent in the advanced coal utilization systems such as gasifiers, fluidized bed combustors, mixed-metal oxide desulfurization systems, diesel engines, and gas turbines.

Proton capture and loss in ion-molecule collisions

International Nuclear Information System (INIS)

Ibanez, S; Alessi, M; Zimmerman, V; Fregenal, D; Focke, P; Bernardi, G; Suarez, S

2007-01-01

We have measured proton distributions from the collision systems Ar + , Kr + on CH 4 molecular targets, searching for atom capture into the projectile continuum. Within the studied energy range (100 to 300 eV/u) we have not distinctive evidence of capture. A small contamination of ion beams with molecular ions as ArH + or KrH + , have shown to be enough to produce peak shaped structures at the projectile velocity. We, therefore, concentrate our study on proton loss from molecular ions in collision with several targets

Integration of the steam cycle and CO2 capture process in a decarbonization power plant

International Nuclear Information System (INIS)

Xu, Gang; Hu, Yue; Tang, Baoqiang; Yang, Yongping; Zhang, Kai; Liu, Wenyi

2014-01-01

A new integrated system with power generation and CO 2 capture to achieve higher techno-economic performance is proposed in this study. In the new system, three measures are adopted to recover the surplus energy from the CO 2 capture process. The three measures are as follows: (1) using a portion of low-pressure steam instead of high-pressure extracted steam by installing the steam ejector, (2) mixing a portion of flash-off water with the extracted steam to utilize the superheat degree of the extracted steam, and (3) recycling the low-temperature waste heat from the CO 2 capture process to heat the condensed water. As a result, the power output of the new integrated system is 107.61 MW higher than that of a decarbonization power plant without integration. The efficiency penalty of CO 2 capture is expected to decrease by 4.91%-points. The increase in investment produced by the new system is 3.25 M$, which is only 0.88% more than the total investment of a decarbonization power plant without integration. Lastly, the cost of electricity and CO 2 avoided is 15.14% and 33.1% lower than that of a decarbonization power generation without integration, respectively. The promising results obtained in this study provide a new approach for large-scale CO 2 removal with low energy penalty and economic cost. - Highlights: • Energy equilibrium in CO 2 capture process is deeply analyzed in this paper. • System integration is conducted in a coal-fired power plant with CO 2 capture. • The steam ejector is introduced to utilize the waste energy from CO 2 capture process. • Thermodynamic, exergy and techno-economic analyses are quantitatively conducted. • Energy-saving effects are found in the new system with minimal investment

Inclusive fitness maximization: An axiomatic approach.

Science.gov (United States)

Okasha, Samir; Weymark, John A; Bossert, Walter

2014-06-07

Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function. Here we develop this idea and place it on a firm footing by employing a standard decision-theoretic methodology. We show how the principle of inclusive fitness maximization and a related principle of quasi-inclusive fitness maximization can be derived from axioms on an individual׳s 'as if preferences' (binary choices) for the case in which phenotypic effects are additive. Our results help integrate evolutionary theory and rational choice theory, help draw out the behavioural implications of inclusive fitness maximization, and point to a possible way in which evolution could lead organisms to implement it. Copyright © 2014 Elsevier Ltd. All rights reserved.

Capture of exogenous attention modulates the attentional blink

DEFF Research Database (Denmark)

Nielsen, Simon; Andersen, Tobias

2011-01-01

When two targets (T1 & T2) are presented in rapid succession, observers often fail to report T2 if they attend to T1. Bottleneck theories propose that this attentional blink (AB) is due to T1 occupying a slow processing stage when T2 is presented. Accordingly, if increasing T1 difficulty increases...... T1 processing time, this should cause a greater AB. Attention capture hypotheses suggest that T1 captures attention, which cannot be reallocated to T2 in time. Accordingly, if increasing T1 difficulty, decreases saliency, this should cause a smaller AB. Studies examining how T1 difficulty affects...... with T1 contrast energy. Our results indicate that T1 capture modulates the AB. We suggest that this effect has confounded previous studies on the effect of T1 difficulty. In an electrophysiological version of the study we will further examine the implied relation between attention capture and the AB....

Bleaching threshold of cationic radicals of alkanes and capture energy of the positive hole of these ions in irradiated solid matrix

International Nuclear Information System (INIS)

Van den Bosch, A.; Strobbe, M.; Ceulemans, J.

1984-01-01

Gamma irradiated Cl 3 CCF 3 shows an absorption band at about 360 nm, and another band, at 600 nm. The band at 600 nm disappears completely by irradiation with light of lambda>610 nm. Cl 3 CCF 3 containing 1% of decane irradiated at 77 K presents the some phenomena. Selective bleaching by photons of increasing energy allows the determination of the threshold for bleaching of cationic radicals of decane trapped in Cl 3 CCF 3 . Distinction between photoinduced charge transfer and photodissociation is obtained by addition of tetramethyl-p-phenylenediame. Showing that bleaching threshold corresponds to the capture energy of the positive hole on decane cationic radical [fr

CO2 Capture from the Air: Technology Assessment and Implications for Climate Policy

Science.gov (United States)

Keith, D. W.

2002-05-01

It is physically possible to capture CO2 directly from the air and immobilize it in geological structures. Today, there are no large-scale technologies that achieve air capture at reasonable cost. Yet, strong arguments suggest that it will comparatively easy to develop practical air capture technologies on the timescales relevant to climate policy [1]. This paper first analyzes the cost of air capture and then assesses the implications for climate policy. We first analyze the lower bound on the cost needed for air capture, describing the thermodynamic and physical limits to the use of energy and land. We then compare the costs of air capture to the cost of capture from combustion exhaust streams. While the intrinsic minimum energy requirement is larger for air capture, we argue that air capture has important structural advantages, such as the reduction of transport costs and the larger potential for economies of scale. These advantages suggest that, in the long-run air capture be competitive with other methods of achieving deep emissions reductions. We provide a preliminary engineering-economic analysis of an air capture system based on CaO to CaCO3 chemical looping [1]. We analyze the possibility of doing the calcination in a modified pressurized fluidized bed combustor (PFBC) burning coal in a CO2 rich atmosphere with oxygen supplied by an air separation unit. The CaCO3-to-coal ratio would be ~2:1 and the system would be nearly thermally neutral. PFBC systems have been demonstrated at capacities of over 100 MW. Such systems already include CaCO3 injection for sulfur control, and operate at suitable temperatures and pressures for calcination. We assess the potential to recover heat from the dissolution of CaO in order to reduce the overall energy requirements. We analyze the possibility of adapting existing large water/air heat exchangers for use as contacting systems to capture CO2 from the air using the calcium hydroxide solution. The implications of air capture

Electron capture cross-section of Au-Fe complex in silicon

International Nuclear Information System (INIS)

Ali, Akbar; Shafi, M; Majid, Abdul

2006-01-01

A deep level transient spectroscopy technique is applied to study the capture cross-section of an iron-gold complex. The thermal ionization energy obtained from emission rate data is found to be E c -0.36 eV. The Au-Fe complex is a single defect having a capture cross-section of 2.48x10 -16 cm 2 for electrons which is independent of temperature

Terminal altitude maximization for Mars entry considering uncertainties

Science.gov (United States)

Cui, Pingyuan; Zhao, Zeduan; Yu, Zhengshi; Dai, Juan

2018-04-01

Uncertainties present in the Mars atmospheric entry process may cause state deviations from the nominal designed values, which will lead to unexpected performance degradation if the trajectory is designed merely based on the deterministic dynamic model. In this paper, a linear covariance based entry trajectory optimization method is proposed considering the uncertainties presenting in the initial states and parameters. By extending the elements of the state covariance matrix as augmented states, the statistical behavior of the trajectory is captured to reformulate the performance metrics and path constraints. The optimization problem is solved by the GPOPS-II toolbox in MATLAB environment. Monte Carlo simulations are also conducted to demonstrate the capability of the proposed method. Primary trading performances between the nominal deployment altitude and its dispersion can be observed by modulating the weights on the dispersion penalty, and a compromised result referring to maximizing the 3σ lower bound of the terminal altitude is achieved. The resulting path constraints also show better satisfaction in a disturbed environment compared with the nominal situation.

Maximization of wave motion within a hydrocarbon reservoir for wave-based enhanced oil recovery

KAUST Repository

Jeong, C.; Kallivokas, L.F.; Kucukcoban, S.; Deng, W.; Fathi, A.

2015-01-01

the mathematical framework necessary for identifying optimal wave source signals that can maximize a desired motion metric (kinetic energy, particle acceleration, etc.) at the target region of interest. We use the apparatus of partial-differential-equation (PDE

Theoretical treatment of electron capture and excitation in two-electron system ion-atom, atom-atom collisions at low to intermediate energy

International Nuclear Information System (INIS)

Kimura, M.

1986-01-01

A review of various theoretical treatments which have been used to study electron-capture and excitation processes in two-electron-system ion-atom, atom-atom collisions at low to intermediate energy is presented. Advantages as well as limitations associated with these theoretical models in application to practical many-electron ion-atom, atom-atom collisions are specifically pointed out. Although a rigorous theoretical study of many-electron systems has just begun so that reports of theoretical calculations are scarce to date in comparison to flourishing experimental activities, some theoretical results are of great interest and provide important information for understanding collision dynamics of the system which contains many electrons. Selected examples are given for electron capture in a multiply charged ion-He collision, ion-pair formation in an atom-atom collision and alignment and orientation in a Li + + He collision. (Auth.)

Framing and bias in CO2 capture and storage communication films: Reflections from a CO2 capture and storage research group.

Science.gov (United States)

Maynard, Carly M; Shackley, Simon

2017-03-01

There has been a growing trend towards incorporating short, educational films as part of research funding and project proposals. Researchers and developers in CO 2 capture and storage are using films to communicate outcomes, but such films can be influenced by experiences and values of the producers. We document the content and presentation of seven online CO 2 capture and storage films to determine how framing occurs and its influence on the tone of films. The core frame presents CO 2 capture and storage as a potential solution to an imminent crisis in climatic warming and lack of a sustainable energy supply. Three subsidiary frames represent CO 2 capture and storage as (1) the only option, (2) a partial option or (3) a scientific curiosity. The results demonstrate that an understanding of the nuanced explicit and implicit messages portrayed by films is essential both for effective framing according to one's intention and for wider public understanding of a field.

Probabilities and energies to obtain the counting efficiency of electron-capture nuclides. KLMN model; Probabilidades y energias de reestructuracion atomica subsiguientes a la captura electronica. Modelo KLMN

Energy Technology Data Exchange (ETDEWEB)

Galiano, G.; Grau, A.

1994-07-01

An intelligent computer program has been developed to obtain the mathematical formulae to compute the probabilities and reduced energies of the different atomic rearrangement pathways following electron-capture decay. Creation and annihilation operators for Auger and X processes have been introduced. Taking into account the symmetries associated with each process, 262 different pathways were obtained. This model allows us to obtain the influence of the M-electro capture in the counting efficiency when the atomic number of the nuclide is high. (Author)

MAXIMIZING HYDROPOWER PRODUCTION FROM RESERVOIRS:THE CASE STUDY OF MARKABA

International Nuclear Information System (INIS)

Jaafar, H.

2014-01-01

Hydropower is a form of renewable energy that is clean and cheap. Under uncertain climatic conditions, maximization of hydropower production becomes a challenging task.Stochastic Dynamic programming (SDP) is a promising optimization algorithm that is usedfor complex non-linear reservoir operational policies and strategies.In this research, a combined simulation-SDPoptimization model isdeveloped andverified for maximizing large-scale hydropower production in a monthly time step. The model isdeveloped to generate optimal operational policies for the Qarawn reservoir in Lebanon and test these policies in real time conditions. The model isused to derive operational regimes for the Qarawn reservoirunder varying flows using transitional probability matrices. Simulating the derived rules and the generated operational policies proved effective in maximizingthe hydropower production from the Markaba power plant. The model could be successfully applied to other hydropower dams in the region. (author)

Selection of the optimum condition for electron capture detector operation

International Nuclear Information System (INIS)

Lasa, J.; Korus, A.

1974-01-01

A method of determination of the optimal work conditions for the electron capture detector is presented in the paper. Physical phenomena which occur in the detector, as well as the energetic dependence of the electron attachment process are taken into consideration. The influence of the kind of carrier gas, temperature, and the parameters of the supplied voltage in both direct and pulse methods on average values of electron energy is described. Dependence of the sensitivity of the electron capture detector on the carrier gas and the polarizing voltage is illustrated for the Model DNW-300 electron capture detector produced in Poland. Practical indications for selecting optimal conditions of electron capture detector operation are given at the end of the paper. (author)

Atom capture and loss in ion molecule collisions

International Nuclear Information System (INIS)

Breinig, M.; Lasley, S.E.; Gaither, C.C. III.

1985-01-01

Progress is reported in measuring the energy and angular distribution of protons emerging with velocity close to the beam velocity from the target region when Ar + beams collide with a CH 4 target and ArH + beams collide with a He target at asymptotically high speeds. The protons result from the transfer of a target constituent to the projectile (atom capture) or from the dissociation of the projectile molecule in the collision (atom loss). For atom capture processes the Thomas peak is clearly observed. 10 refs., 3 figs

Optimized capture section for a muon accelerator front end

Directory of Open Access Journals (Sweden)

Hisham Kamal Sayed

2014-07-01

Full Text Available In a muon accelerator complex, a target is bombarded by a multi-MW proton beam to produce pions, which decay into the muons which are thereafter bunched, cooled, and accelerated. The front end of the complex captures those pions, then manipulates their phase space, and that of the muons into which they decay, to maximize the number of muons within the acceptance of the downstream systems. The secondary pion beam produced at the target is captured by a high field target solenoid that tapers down to a constant field throughout the rest of the front end. In this study we enhance the useful muon flux by introducing a new design of the longitudinal profile of the solenoid field at, and downstream of, the target. We find that the useful muon flux exiting the front end is larger when the field at the target is higher, the distance over which the field tapers down is shorter, and the field at the end of the taper is higher. We describe how the solenoid field profile impacts the transverse and longitudinal phase space of the beam and thereby leads to these dependencies.

Multi-fuel multi-product operation of IGCC power plants with carbon capture and storage (CCS)

International Nuclear Information System (INIS)

Cormos, Ana-Maria; Dinca, Cristian; Cormos, Calin-Cristian

2015-01-01

This paper investigates multi-fuel multi-product operation of IGCC plants with carbon capture and storage (CCS). The investigated plant designs co-process coal with different sorts of biomass (e.g. sawdust) and solid wastes, through gasification, leading to different decarbonised energy vectors (power, hydrogen, heat, substitute natural gas etc.) simultaneous with carbon capture. Co-gasification of coal with different renewable energy sources coupled with carbon capture will pave the way towards zero emissions power plants. The energy conversions investigated in the paper were simulated using commercial process flow modelling package (ChemCAD) in order to produce mass and energy balances necessary for the proposed evaluation. As illustrative cases, hydrogen and power co-generation and Fischer–Tropsch fuel synthesis (both with carbon capture), were presented. The case studies investigated in the paper produce a flexible ratio between power and hydrogen (in the range of 400–600 MW net electricity and 0–200 MW th hydrogen considering the lower heating value) with at least 90% carbon capture rate. Special emphasis were given to fuel selection criteria for optimisation of gasification performances (fuel blending), to the selection criteria for gasification reactor in a multi-fuel multi-product operation scenario, modelling and simulation of whole process, to thermal and power integration of processes, flexibility analysis of the energy conversion processes, in-depth techno-economic and environmental assessment etc. - Highlights: • Assessment of IGCC-based energy vectors poly-generation systems with CCS. • Optimisation of gasification performances and CO 2 emissions by fuel blending. • Multi-fuel multi-product operation of gasification plants

A current controlled matrix converter for wind energy conversion systems based on permanent magnet synchronous generator

Directory of Open Access Journals (Sweden)

Naggar H. Saad

2016-05-01

Full Text Available The main challenges of wind energy conversion systems (WECS are to maximize the energy capture from the wind and injecting reactive power during the fault. This paper presents a current controlled matrix converter to interface Permanent Magnet Synchronous Generators (PMSG based WECS with the grid. To achieve fast dynamic response with reduced current ripples, a hysteresis current control is utilized. The proposed control system decouples the active and reactive components of the PMSG current to extract the maximum power from the wind at a given wind velocity and to inject reactive power to the grid. Reactive power injection during the fault satisfying the grid-codes requirement. The proposed WECS has been modeled and simulated using PSCAD/EMTDC software package.

Upscaling of enzyme enhanced CO2 capture

DEFF Research Database (Denmark)

Gladis, Arne Berthold

Fossil fuels are the backbone of the energy generation in the coming decades for USA, China, India and Europe, hence high greenhouse gas emissions are expected in future. Carbon capture and storage technology (CCS) is the only technology that can mitigate greenhouse gas emissions from fossil fuel...... the mass transfer of CO2 with slow-capturing but energetically favorable solvents can open up a variety of new process options for this technology. The ubiquitous enzyme carbonic anhydrase (CA), which enhances the mass transfer of CO2 in the lungs by catalyzing the reversible hydration of CO2, is one very...... enhanced CO2 capture technology by identifying the potentials and limitations in lab and in pilot scale and benchmarking the process against proven technologies. The main goal was to derive a realistic process model for technical size absorbers with a wide range of validity incorporating a mechanistic...

Maximal Inequalities for Dependent Random Variables

DEFF Research Database (Denmark)

Hoffmann-Jorgensen, Jorgen

2016-01-01

Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X-k. Then a......Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X......-k. Then a maximal inequality gives conditions ensuring that the maximal partial sum M-n = max(1) (...

An ethical justification of profit maximization

DEFF Research Database (Denmark)

Koch, Carsten Allan

2010-01-01

In much of the literature on business ethics and corporate social responsibility, it is more or less taken for granted that attempts to maximize profits are inherently unethical. The purpose of this paper is to investigate whether an ethical argument can be given in support of profit maximizing...... behaviour. It is argued that some form of consequential ethics must be applied, and that both profit seeking and profit maximization can be defended from a rule-consequential point of view. It is noted, however, that the result does not apply unconditionally, but requires that certain form of profit (and...... utility) maximizing actions are ruled out, e.g., by behavioural norms or formal institutions....

Effect of Ramadan observance on maximal muscular performance of trained men.

Science.gov (United States)

Bouhlel, Hatem; Shephard, Roy J; Gmada, Nebil; Aouichaoui, Chirine; Peres, Gilbert; Tabka, Zouhair; Bouhlel, Ezdine

2013-05-01

To assess the influence of Ramadan fasting on maximal performance of moderately trained young men using various tests of muscle performance. Comparison of Ramadan fasting (n = 10) versus control group (n = 10) over 3 test sessions, before Ramadan (B), at the end of the first week of Ramadan (R-1), and during the fourth week of Ramadan (R-4). At each 2-day test session, 4 tests were performed in the same order: measurement of vertical jump height (VJH) and a force-velocity test using the arms on day 1, and measurement of handgrip force (HGF), and a force-velocity test using the legs on day 2. Twenty trained men. Maximal power of the arms and of the legs (force-velocity testing), vertical jump performance, HGF, anthropometric data, dietary intake, hemoglobin, and hematocrit. Two-way analyses of variance (group × time) showed Ramadan fasters with decreased maximal anaerobic power of the arms (Wmax-A) and legs (Wmax-L) at R-1, with a partial return of arm data to initial values at R-4. Vertical jump height and HGF remained unchanged throughout. Other changes in Ramadan observers were a decreased energy intake and a decrease of plasma volume at R-1. These results suggest that Ramadan observance initially had detrimental effects on Wmax-A, and Wmax-L, with a tendency to recovery by week 4 of Ramadan. Reductions of total energy intake and intramuscular glycogen may contribute to the reduced Wmax-A and Wmax-L during Ramadan fasting.

12C+16O sub-barrier radiative capture cross-section measurements

International Nuclear Information System (INIS)

Goasduff, A.; Courtin, S.; Haas, F.; Beck, C.; Lebhertz, D.; Jenkins, D.G.; Fallis, J.; Ruiz, C.; Hutcheon, D.A.; Amandruz, P.A.; Davis, C.; Hager, U.; Ottewell, D.; Ruprecht, G.

2011-01-01

We have performed a heavy ion radiative capture reaction between two light heavy ions, 12 C and 16 O, leading to 28 Si. The present experiment has been performed below Coulomb barrier energies in order to reduce the phase space and to try to shed light on structural effects. Obtained γ-spectra display a previously unobserved strong feeding of intermediate states around 11 MeV at these energies. This new decay branch is not fully reproduced by statistical nor semi-statistical decay scenarios and may imply structural effects. Radiative capture cross-sections are extracted from the data. (authors)

Energy Decision Science and Informatics | Integrated Energy Solutions |

Science.gov (United States)

NREL Decision Science and Informatics Energy Decision Science and Informatics NREL utilizes and advances state-of-the-art decision science and informatics to help partners make well-informed energy decisions backed by credible, objective data analysis and insights to maximize the impact of energy

Electron capture cross-section of Au-Fe complex in silicon

Energy Technology Data Exchange (ETDEWEB)

Ali, Akbar; Shafi, M; Majid, Abdul [Advance Materials Physics Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad (Pakistan)

2006-10-15

A deep level transient spectroscopy technique is applied to study the capture cross-section of an iron-gold complex. The thermal ionization energy obtained from emission rate data is found to be E{sub c} -0.36 eV. The Au-Fe complex is a single defect having a capture cross-section of 2.48x10{sup -16} cm{sup 2} for electrons which is independent of temperature.

Measurement of neutron captured cross-sections in 1-2 MeV

Energy Technology Data Exchange (ETDEWEB)

Kim, Gi Dong; Kim, Young Sek; Kim, Jun Kon; Yang, Tae Keun [Korea Institutes of Geoscience and Mineral Resources, Taejeon (Korea)

2001-04-01

The measurement of neutron captured reaction cross sections was performed to build the infra system for the production of nuclear data. MeV neutrons were produced with TiT target and {sup 3}T(p,n){sup 3}He reaction. The characteristics of TiT thin film was analyzed with ERD-TOF and RBS. The results was published at Journal of the Korea Physical Society (SCI registration). The energy, the energy spread and the flux of the produced neutron were measured. The neutron excitation functions of {sup 12}C and {sup 16}O were obtained to confirm the neutron energy and neutron energy spread. The neutron energy spread found to be 1.3 % at the neutron energy of 2.077 MeV. The {sup 197}Au(n,{gamma}) reaction was performed to obtain the nerutron flux. The maximum neutron flux found to be 1 x 10{sup 8} neutrons/sec at the neutron energy of 2 MeV. The absolute efficiency of liquid scintillation detector was obtained in the neutron energy of 1 - 2 MeV. The fast neutron total reaction cross sections of Cu, Fe, and Au were measured with sample in-out method. Also the neutron captured reaction cross sections of {sup 63}Cu were measured with fast neutron activation method. The measurement of neutron total reaction cross sections and the neutron captured reaction cross sections with fast neutrons were first tried in Korea. The beam pulsing system was investigated and the code of calculating the deposition spectrums for primary gamma rays was made to have little errors at nuclear data. 25 refs., 28 figs., 14 tabs. (Author)

Inclusive Fitness Maximization:An Axiomatic Approach

OpenAIRE

Okasha, Samir; Weymark, John; Bossert, Walter

2014-01-01

Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function. Here we develop this idea and place it on a firm footing by employing a standard decision-theoretic methodology. We show how the principle of inclusive fitness maximization and a related principle of qu...

Dynamics of fragment capture for cluster structures of weakly bound 7Li

Directory of Open Access Journals (Sweden)

Shrivastava A.

2013-12-01

Full Text Available Role of cluster structures of 7Li on reaction dynamics have been studied by performing exclusive measurements of prompt-γ rays from residues with scattered particles at energy, E/Vb = 1.6, with 198Pt target. Yields of the residues resulting after capture of t and 4,5,6He, corresponding to different excitation energies of the composite system were estimated. The results were compared with three body classical-dynamical model for breakup fusion, constrained by the measured fusion, α and t capture cross-sections. The cross-section of residues from capture of α and t agreed well with the prediction of the model showing dominance of the two step process - breakup fusion, while those from tightly bound 6He showed massive transfer to be the dominant mechanism.

Does mental exertion alter maximal muscle activation?

Directory of Open Access Journals (Sweden)

Vianney eRozand

2014-09-01

Full Text Available Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 minutes each: i high mental exertion (incongruent Stroop task, ii moderate mental exertion (congruent Stroop task, iii low mental exertion (watching a movie. In each condition, mental exertion was combined with ten intermittent maximal voluntary contractions of the knee extensor muscles (one maximal voluntary contraction every 3 minutes. Neuromuscular function was assessed using electrical nerve stimulation. Maximal voluntary torque, maximal muscle activation and other neuromuscular parameters were similar across mental exertion conditions and did not change over time. These findings suggest that mental exertion does not affect neuromuscular function during intermittent maximal voluntary contractions of the knee extensors.

Approaching maximal performance of longitudinal beam compression in induction accelerator drivers

International Nuclear Information System (INIS)

Mark, J.W.K.; Ho, D.D.M.; Brandon, S.T.; Chang, C.L.; Drobot, A.T.; Faltens, A.; Lee, E.P.; Krafft, G.A.

1986-01-01

Longitudinal beam compression occurs before final focus and fusion chamber beam transport and is a key process determining initial conditions for final focus hardware. Determining the limits for maximal performance of key accelerator components is an essential element of the effort to reduce driver costs. Studies directed towards defining the limits of final beam compression including considerations such as maximal available compression, effects of longitudinal dispersion and beam emittance, combining pulse-shaping with beam compression to reduce the total number of beam manipulators, etc., are given. Several possible techniques are illustrated for utilizing the beam compression process to provide the pulse shapes required by a number of targets. Without such capabilities to shape the pulse, an additional factor of two or so of beam energy would be required by the targets

Modulational estimate for the maximal Lyapunov exponent in Fermi-Pasta-Ulam chains

Science.gov (United States)

Dauxois, Thierry; Ruffo, Stefano; Torcini, Alessandro

1997-12-01

In the framework of the Fermi-Pasta-Ulam (FPU) model, we show a simple method to give an accurate analytical estimation of the maximal Lyapunov exponent at high energy density. The method is based on the computation of the mean value of the modulational instability growth rates associated to unstable modes. Moreover, we show that the strong stochasticity threshold found in the β-FPU system is closely related to a transition in tangent space, the Lyapunov eigenvector being more localized in space at high energy.

A projection of energy consumption and carbon dioxide emissions in the electricity sector for Saudi Arabia: The case for carbon capture and storage and solar photovoltaics

International Nuclear Information System (INIS)

Mansouri, Noura Y.; Crookes, Roy J.; Korakianitis, Theodosios

2013-01-01

The paper examined the case study of the Saudi electricity sector and provided projections for energy use and respective carbon dioxide (CO 2 ) emissions for the period 2010–2025 with and without cleaner energy technologies. Based on two sets of 20 life cycle assessment studies for carbon capture and storage and solar photovoltaic technologies, CO 2 emission reduction rates were used for projecting future CO 2 emissions. Results showed enormous savings in CO 2 emissions, for the most likely case, year 2025 reported savings that range from 136 up to 235 MtCO 2 . Including low growth and high growth cases, these savings could range from 115 up to 468 MtCO 2 presenting such an unrivalled opportunity for Saudi Arabia. These projections were developed as a way of translating the inherent advantages that cleaner energy technologies could provide for CO 2 emissions savings. It is hoped that the results of this paper would inform energy policymaking in Saudi Arabia. - Highlights: • Electricity use in Saudi Arabia is predicted in the period 2010–2025. • Use of photovoltaic plants and carbon capture and storage are considered. • Life cycle assessment of the options is conducted. • Carbon emissions with and without the renewable energy are estimated. • The projections showcase the CO 2 emissions savings

Lovelock black holes with maximally symmetric horizons

Energy Technology Data Exchange (ETDEWEB)

Maeda, Hideki; Willison, Steven; Ray, Sourya, E-mail: hideki@cecs.cl, E-mail: willison@cecs.cl, E-mail: ray@cecs.cl [Centro de Estudios CientIficos (CECs), Casilla 1469, Valdivia (Chile)

2011-08-21

We investigate some properties of n( {>=} 4)-dimensional spacetimes having symmetries corresponding to the isometries of an (n - 2)-dimensional maximally symmetric space in Lovelock gravity under the null or dominant energy condition. The well-posedness of the generalized Misner-Sharp quasi-local mass proposed in the past study is shown. Using this quasi-local mass, we clarify the basic properties of the dynamical black holes defined by a future outer trapping horizon under certain assumptions on the Lovelock coupling constants. The C{sup 2} vacuum solutions are classified into four types: (i) Schwarzschild-Tangherlini-type solution; (ii) Nariai-type solution; (iii) special degenerate vacuum solution; and (iv) exceptional vacuum solution. The conditions for the realization of the last two solutions are clarified. The Schwarzschild-Tangherlini-type solution is studied in detail. We prove the first law of black-hole thermodynamics and present the expressions for the heat capacity and the free energy.

Electron capture in collisions of S{sup 4+} with helium

Energy Technology Data Exchange (ETDEWEB)

Wang, J.G.; Stancil, P.C. [Department of Physics and Astronomy and Center for Simulational Physics, University of Georgia, Athens, GA (United States)]. E-mails: wangjg@physast.uga.edu; stancil@physast.uga.edu; Turner, A.R.; Cooper, D.L. [Department of Chemistry, University of Liverpool (United Kingdom)]. E-mail: dlc@liv.ac.uk; Schultz, D.R.; Rakovic, M.J. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)]. E-mails: schultzd@ornl.gov; milun@mail.phy.ornl.gov; Fritsch, W. [Abteilung Theoretische Physik, Hahn-Meitner-Institut Berlin, Berlin (Germany)]. E-mail: fritsch@hmi.de; Zygelman, B. [Department of Physics, University of Nevada, Las Vegas, NV (United States)]. E-mail: bernard@physics.unlv.edu

2002-07-28

Charge transfer due to collisions of ground-state S{sup 4+}(3s{sup 2} {sup 1}S) ions with helium is investigated for energies between 0.1 meV u{sup -1} and 10 MeV u{sup -1}. Total and state-selective single electron capture (SEC) cross sections and rate coefficients are obtained utilizing the quantum mechanical molecular-orbital close-coupling (MOCC), atomic-orbital close-coupling (AOCC), classical trajectory Monte Carlo (CTMC) and continuum distorted wave methods. The MOCC calculations utilize ab initio adiabatic potentials and nonadiabatic radial coupling matrix elements obtained with the spin-coupled valence-bond approach. Previous data are limited to a calculation of the total SEC rate coefficient using the Landau-Zener model that is, in comparison to the results presented here, three orders of magnitude smaller. The MOCC SEC cross sections at low energy reveal a multichannel interference effect. True double capture is also investigated with the AOCC and CTMC approaches while autoionizing double capture and transfer ionization (TI) is explored with CTMC. SEC is found to be the dominant process except for E>200 keV u{sup -1} when TI becomes the primary capture channel. Astrophysical implications are briefly discussed. (author)

Analytical and computational modelling for wave energy systems: the example of oscillating wave surge converters

Science.gov (United States)

Dias, Frédéric; Renzi, Emiliano; Gallagher, Sarah; Sarkar, Dripta; Wei, Yanji; Abadie, Thomas; Cummins, Cathal; Rafiee, Ashkan

2017-08-01

The development of new wave energy converters has shed light on a number of unanswered questions in fluid mechanics, but has also identified a number of new issues of importance for their future deployment. The main concerns relevant to the practical use of wave energy converters are sustainability, survivability, and maintainability. Of course, it is also necessary to maximize the capture per unit area of the structure as well as to minimize the cost. In this review, we consider some of the questions related to the topics of sustainability, survivability, and maintenance access, with respect to sea conditions, for generic wave energy converters with an emphasis on the oscillating wave surge converter. New analytical models that have been developed are a topic of particular discussion. It is also shown how existing numerical models have been pushed to their limits to provide answers to open questions relating to the operation and characteristics of wave energy converters.

Analytical and computational modelling for wave energy systems: the example of oscillating wave surge converters.

Science.gov (United States)

Dias, Frédéric; Renzi, Emiliano; Gallagher, Sarah; Sarkar, Dripta; Wei, Yanji; Abadie, Thomas; Cummins, Cathal; Rafiee, Ashkan

2017-01-01

The development of new wave energy converters has shed light on a number of unanswered questions in fluid mechanics, but has also identified a number of new issues of importance for their future deployment. The main concerns relevant to the practical use of wave energy converters are sustainability, survivability, and maintainability. Of course, it is also necessary to maximize the capture per unit area of the structure as well as to minimize the cost. In this review, we consider some of the questions related to the topics of sustainability, survivability, and maintenance access, with respect to sea conditions, for generic wave energy converters with an emphasis on the oscillating wave surge converter. New analytical models that have been developed are a topic of particular discussion. It is also shown how existing numerical models have been pushed to their limits to provide answers to open questions relating to the operation and characteristics of wave energy converters.

Assessing socio-technical mindsets: Public deliberations on carbon capture and storage in the context of energy sources and climate change

International Nuclear Information System (INIS)

Einsiedel, Edna F.; Boyd, Amanda D.; Medlock, Jennifer; Ashworth, Peta

2013-01-01

The adaptation and transition to new configurations of energy systems brought on by challenges of climate change, energy security, and sustainability have encouraged more integrative approaches that bring together the social and technical dimensions of technology. The perspectives of energy systems and climate change play an important role in the development and implementation of emerging energy technologies and attendant policies on greenhouse gas reduction. This research examines citizens’ views on climate change and a number of energy systems, with a specific focus on the use of carbon capture and storage (CCS) as a technology to address greenhouse gas emissions. An all-day workshop with 82 local participants was held in the city of Calgary in Alberta, Canada to explore the views of climate change, energy and CCS. Participants were provided the opportunity to ask experts questions and discuss in small groups their views of climate change policy and energy systems. Results demonstrate that participants’ assessments of energy systems are influenced by social–political–institutional–economic contexts such as trust in industry and government, perception of parties benefiting from the technology, and tradeoffs between energy systems. We discuss our findings in the context of understanding social learning processes as part of socio-technical systems change. - Highlight: ► Energy systems are judged in the context of wider socio-technical system dimensions. ► Skepticism about climate change may affect support for CCS. ► Concerns about CCS include: CO 2 leaks, accuracy of monitoring and costs.

Boron neutron capture therapy using mixed epithermal and thermal neutron beams in patients with malignant glioma-correlation between radiation dose and radiation injury and clinical outcome

International Nuclear Information System (INIS)

Kageji, Teruyoshi; Nagahiro, Shinji; Matsuzaki, Kazuhito; Mizobuchi, Yoshifumi; Toi, Hiroyuki; Nakagawa, Yoshinobu; Kumada, Hiroaki

2006-01-01

Purpose: To clarify the correlation between the radiation dose and clinical outcome of sodium borocaptate-based intraoperative boron neutron capture therapy in patients with malignant glioma. Methods and Materials: The first protocol (P1998, n = 8) prescribed a maximal gross tumor volume (GTV) dose of 15 Gy. In 2001, a dose-escalated protocol was introduced (P2001, n 11), which prescribed a maximal vascular volume dose of 15 Gy or, alternatively, a clinical target volume (CTV) dose of 18 Gy. Results: The GTV and CTV doses in P2001 were 1.1-1.3 times greater than those in P1998. The maximal vascular volume dose of those with acute radiation injury was 15.8 Gy. The mean GTV and CTV dose in long-term survivors with glioblastoma was 26.4 and 16.5 Gy, respectively. A statistically significant correlation between the GTV dose and median survival time was found. In the 11 glioblastoma patients in P2001, the median survival time was 19.5 months and 1- and 2-year survival rate was 60.6% and 37.9%, respectively. Conclusion: Dose escalation contributed to the improvement in clinical outcome. To avoid radiation injury, the maximal vascular volume dose should be <12 Gy. For long-term survival in patients with glioblastoma after boron neutron capture therapy, the optimal mean dose of the GTV and CTV was 26 and 16 Gy, respectively

Doped phosphorene for hydrogen capture: A DFT study

Science.gov (United States)

Zhang, Hong-ping; Hu, Wei; Du, Aijun; Lu, Xiong; Zhang, Ya-ping; Zhou, Jian; Lin, Xiaoyan; Tang, Youhong

2018-03-01

Hydrogen capture and storage is the core of hydrogen energy application. With its high specific surface area, direct bandgap, and variety of potential applications, phosphorene has attracted much research interest. In this study, density functional theory (DFT) is utilized to study the interactions between doped phosphorenes and hydrogen molecules. The effects of different dopants and metallic or nonmetallic atoms on phosphorene/hydrogen interactions is systematically studied by adsorption energy, electron density difference, partial density of states analysis, and Hirshfeld population. Our results indicate that the metallic dopants Pt, Co, and Ni can help to improve the hydrogen capture ability of phosphorene, whereas the nonmetallic dopants have no effect on it. Among the various metallic dopants, Pt performs very differently, such that it can help to dissociate H2 on phosphorene. Specified doped phosphorene could be a promising candidate for hydrogen storage, with behaviors superior to those of intrinsic graphene sheet.

On maximal surfaces in asymptotically flat space-times

International Nuclear Information System (INIS)

Bartnik, R.; Chrusciel, P.T.; O Murchadha, N.

1990-01-01

Existence of maximal and 'almost maximal' hypersurfaces in asymptotically flat space-times is established under boundary conditions weaker than those considered previously. We show in particular that every vacuum evolution of asymptotically flat data for Einstein equations can be foliated by slices maximal outside a spatially compact set and that every (strictly) stationary asymptotically flat space-time can be foliated by maximal hypersurfaces. Amongst other uniqueness results, we show that maximal hypersurface can be used to 'partially fix' an asymptotic Poincare group. (orig.)

The hybrid MPC-MINLP algorithm for optimal operation of coal-fired power plants with solvent based post-combustion CO2 capture

Directory of Open Access Journals (Sweden)

Norhuda Abdul Manaf

2017-03-01

Full Text Available This paper presents an algorithm that combines model predictive control (MPC with MINLP optimization and demonstrates its application for coal-fired power plants retrofitted with solvent based post-combustion CO2 capture (PCC plant. The objective function of the optimization algorithm works at a primary level to maximize plant economic revenue while considering an optimal carbon capture profile. At a secondary level, the MPC algorithm is used to control the performance of the PCC plant. Two techno-economic scenarios based on fixed (capture rate is constant and flexible (capture rate is variable operation modes are developed using actual electricity prices (2011 with fixed carbon prices ($AUD 5, 25, 50/tonne-CO2 for 24 h periods. Results show that fixed operation mode can bring about a ratio of net operating revenue deficit at an average of 6% against the superior flexible operation mode.

Chemistry of sustainable energy

CERN Document Server

Carpenter, Nancy E

2014-01-01

Energy BasicsWhat Is Energy?Energy, Technology, and SustainabilityEnergy Units, Terms, and AbbreviationsElectricity Generation and StorageOther ResourcesReferencesFossil FuelsFormation of Oil and GasExtraction of Fossil FuelsRefiningCarbon Capture and StorageSummaryOther ResourcesOnline Resources Related to Carbon Capture andSequestrationReferencesThermodynamicsIntroductionThe First Law of ThermodynamicsThe Second Law and Thermodynamic Cycles: the Carnot EfficiencyExerg

Insulin resistance and maximal oxygen uptake

DEFF Research Database (Denmark)

Seibaek, Marie; Vestergaard, Henrik; Burchardt, Hans

2003-01-01

BACKGROUND: Type 2 diabetes, coronary atherosclerosis, and physical fitness all correlate with insulin resistance, but the relative importance of each component is unknown. HYPOTHESIS: This study was undertaken to determine the relationship between insulin resistance, maximal oxygen uptake......, and the presence of either diabetes or ischemic heart disease. METHODS: The study population comprised 33 patients with and without diabetes and ischemic heart disease. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp; maximal oxygen uptake was measured during a bicycle exercise test. RESULTS......: There was a strong correlation between maximal oxygen uptake and insulin-stimulated glucose uptake (r = 0.7, p = 0.001), and maximal oxygen uptake was the only factor of importance for determining insulin sensitivity in a model, which also included the presence of diabetes and ischemic heart disease. CONCLUSION...

Application of optimal design methodologies in retrofitting natural gas combined cycle power plants with CO_2 capture

International Nuclear Information System (INIS)

Pan, Ming; Aziz, Farah; Li, Baohong; Perry, Simon; Zhang, Nan; Bulatov, Igor; Smith, Robin

2016-01-01

Highlights: • A new approach is proposed for retrofitting NGCC power plants with CO2 capture. • HTI techniques are developed for improving heat recovery in NGCC power plants. • EGR techniques are developed to increase the process overall energy efficiency. • The proposed methods are efficient for practical application. - Abstract: Around 21% of the world’s power production is based on natural gas. Energy production is considered to be the significant sources of carbon dioxide (CO_2) emissions. This has a significant effect on the global warming. Improving power plant efficiency and adding a CO_2 capture unit into power plants, have been suggested to be a promising countermeasure against global warming. This paper presents a new insight to the application of energy efficient technologies in retrofitting natural gas combined cycle (NGCC) power plants with CO_2 capture. High fidelity models of a 420 MW NGCC power plant and a CO_2 capture plant with CO_2 compression train have been built and integrated for 90% capture level. These models have been then validated by comparisons with practical operating data and literature results. The novelty of the paper is to propose optimal retrofitting strategies to minimize the efficiency penalty caused by integrating carbon capture units into the power plant, including (1) implementing heat transfer intensification techniques to increase energy saving in the heat recovery steam generator (HRSG) of the power plant; (2) extracting suitable steam from the HRSG to supply the heat required by the capture process, thus on external heat is purchased; (3) employing exhaust gas recirculation (EGR) to increase the overall energy efficiency of the integrated process, which can benefit both power plant (e.g. increasing power plant efficiency) and capture process (e.g. reducing heat demands). Compared with the base case without using any integrating and retrofitting strategies, the optimal solution based on the proposed approaches

A low energy aqueous ammonia CO₂ capture process

DEFF Research Database (Denmark)

Gaspar, Jozsef; Waseem Arshad, Muhammad; Blaker, Eirik Ask

2014-01-01

of the process. The present capture alternative is especially convenient for power plants but is also beneficial for the cement, steel and aluminum industry. Special attention is given to the ammonia slip prediction. The calculations substantiate that the slip above the absorber is 0.1 mol % after washing...

Stellar Neutron Capture Cross Sections of the Lu and Hf Isotopes

International Nuclear Information System (INIS)

Wisshak, K.; Voss, F.; Kaeppeler, F.; Kazakov, L.; Krticka, M.

2005-01-01

The neutron capture cross sections of 175,176Lu and 176,177,178,179,180Hf have been measured in the energy range from 3 to 225 keV at the Karlsruhe 3.7 MV Van de Graaff accelerator relative to the gold standard. Neutrons were produced by the 7Li(p,n)7Be reaction and capture events were detected by the Karlsruhe 4πBaF2 detector. The cross section ratios could be determined with uncertainties between 0.9 and 1.8% about a factor of five more accurate than previous data. A strong population of isomeric states was found in neutron capture of the Hf isotopes, which are only partially explained by CASINO/GEANT simulations based on the known level schemes.Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT = 8 keV and 100 keV. Severe differences up to40% were found to the data of a recent evaluation based on existing experimental results. The new data allow for a much more reliable analysis of the important branching in the s-process synthesis path at 176Lu which can be interpreted as an s-process thermometer

POLITENESS MAXIM OF MAIN CHARACTER IN SECRET FORGIVEN

Directory of Open Access Journals (Sweden)

Sang Ayu Isnu Maharani

2017-06-01

Full Text Available Maxim of Politeness is an interesting subject to be discussed, since politeness has been criticized from our childhood. We are obliques to be polite to anyone either in speaking or in acting. Somehow we are manage to show politeness in our spoken expression though our intention might be not so polite. For example we must appriciate others opinion although we feel objection toward the opinion. In this article the analysis of politeness is based on maxim proposes by Leech. He proposed six types of politeness maxim. The discussion shows that the main character (Kristen and Kami use all types of maxim in their conversation. The most commonly used are approbation maxim and agreement maxim

CO₂ Capture Membrane Process for Power Plant Flue Gas

Energy Technology Data Exchange (ETDEWEB)

Toy, Lora [Research Triangle Inst. International, Research Triangle Park, NC (United States); Kataria, Atish [Research Triangle Inst. International, Research Triangle Park, NC (United States); Gupta, Raghubir [Research Triangle Inst. International, Research Triangle Park, NC (United States)

2012-04-01

Because the fleet of coal-fired power plants is of such importance to the nation's energy production while also being the single largest emitter of CO₂, the development of retrofit, post-combustion CO₂ capture technologies for existing and new, upcoming coal power plants will allow coal to remain a major component of the U.S. energy mix while mitigating global warming. Post-combustion carbon capture technologies are an attractive option for coal-fired power plants as they do not require modification of major power-plant infrastructures, such as fuel processing, boiler, and steam-turbine subsystems. In this project, the overall objective was to develop an advanced, hollow-fiber, polymeric membrane process that could be cost-effectively retrofitted into current pulverized coal-fired power plants to capture at least 90% of the CO₂ from plant flue gas with 95% captured CO₂ purity. The approach for this project tackled the technology development on three different fronts in parallel: membrane materials R&D, hollow-fiber membrane module development, and process development and engineering. The project team consisted of RTI (prime) and two industrial partners, Arkema, Inc. and Generon IGS, Inc. Two CO₂-selective membrane polymer platforms were targeted for development in this project. For the near term, a next-generation, high-flux polycarbonate membrane platform was spun into hollow-fiber membranes that were fabricated into both lab-scale and larger prototype (~2,200 ft²) membrane modules. For the long term, a new fluoropolymer membrane platform based on poly(vinylidene fluoride) [PVDF] chemistry was developed using a copolymer approach as improved capture membrane materials with superior chemical resistance to flue-gas contaminants (moisture, SO₂, NO_x, etc.). Specific objectives were: - Development of new, highly chemically resistant, fluorinated polymers as membrane materials with minimum selectivity of 30 for CO₂ over N₂ and CO�

Optimal topology of urban buildings for maximization of annual solar irradiation availability using a genetic algorithm

International Nuclear Information System (INIS)

Conceição António, Carlos A.; Monteiro, João Brasileiro; Afonso, Clito Félix

2014-01-01

An approach based on the optimal placement of buildings that favors the use of solar energy is proposed. By maximizing the area of exposure to incident solar irradiation on roofs and facades of buildings, improvements on the energy performance of the urban matrix are reached, contributing decisively to reduce dependence on other less environmentally friendly energy options. A mathematical model is proposed to optimize the annual solar irradiation availability where the placement of the buildings in urban environment favors the use of solar energy resource. Improvements on the solar energy potential of the urban grid are reached by maximizing the exposure of incident solar irradiation on roofs and facades of buildings. The proposed model considers predominant, the amount of direct solar radiation, omitting the components of the solar irradiation diffused and reflected. The dynamic interaction of buildings on exposure to sunlight is simulated aiming to evaluate the shadowing zones. The incident solar irradiation simulation and the dynamic shading model were integrated in an optimization approach implemented numerically. The search for optimal topological solutions for urban grid is based on a Genetic Algorithm. The objective is to generate optimal scenarios for the placement of buildings into the urban grid in the pre-design phase, which enhances the use of solar irradiation. - Highlights: • A mathematical model is proposed to optimize annual solar irradiation availability. • Maximization of incident solar irradiation on roofs and facades of buildings. • Dynamic interaction of buildings is simulated aiming to evaluate shadowing zones. • Search for optimal topological solutions for urban grid based on genetic algorithm. • Solutions are compared with the conventional configurations for urban grid

Clean Coal: myth or reality? At the heart of the energy-climate equation, capturing and storing CO2 - Proceedings of the 2007 Le Havre's international meetings

International Nuclear Information System (INIS)

Rufenacht, Antoine; Brodhag, Christian; Mocilnikar, Antoine-Tristan; Bennaceur, Kamel; Esseid, Ablaziz; Lemoine, Stephane; Prevot, Henri; Diercks, Thorsten; Jaclot, Francois; Fache, Dominique; Coulon, Pierre-Jean; Capris, Renaud; TRANIE, Jean-Pascal; Le Thiez, Pierre; Marliave, Luc de; Perrin, Nicolas; Paelinck, Philippe; Clodic, Denis; Thabussot, Laurent; Alf, Martin; Boon, Gustaaf; Giger, Francois; Bisseaud, Jean-Michel; Michel, Patrick; Poyer, Luc; Biebuyck, Christian; Kalaydjian, Francois; Roulet, Claude; Bonijoly, Didier; Gresillon, Francois Xavier; Bonneville, Alain; Tauziede, Christian; Munier, Gilles; Moncomble, Jean-Eudes; Frois, Bernard; Charmant, Marcel; Thybaud, Nathalie; Fares, Tewfik; Lacave, Jean-Marc; Duret, Benoit; Gerard, Bernard

2007-03-01

This document comprises the French and English versions of the executive summary of the RIH 2007 meetings, followed by the available presentations (slides). Content: - Symposium Opening: Government and the Coal Issue; 1 - First Session - Energy, Climate, Coal: - Scenarios for energy technologies and CO 2 emissions: Energy outlooks, CO 2 emissions, Technologies (Kamel BENNACEUR); - The global situation of coal: The situation of the international steam coal market, Change in this market, Total's position in this business, Major challenges for the future (Ablaziz ESSEID); - Coal markets: availability, competitiveness, and growing maturity (Stephane LEMOINE); - Coal in the geopolitics of greenhouse gases (Henri PREVOT); - Questions; 2 - Second Session - Coal Economy: - Opportunities and challenges for coal in the European energy mix: the Commission's energy package: The European situation, The European energy mix, The role of EURACOAL (Thorsten DIERCKS); - The development of a coal bed in Lucenay-les-Aix and Cossaye in the Massif Central (Francois JACLOT); - The Russian view of coal's place in the energy mix (Dominique FACHE); - Coal, a key to development in Niger (Pierre-Jean COULON); - The energy and environmental efficiency of coal-fired power plants associated with heating networks (Renaud CAPRIS); - The Valorca project: efficient and immediate use of coal, and strong outlooks for the future (Jean-Pascal TRANIE); - Questions; 3 - Third and Forth Sessions - Clean Power Plants: - CO 2 capture systems (Pierre LE THIEZ); - CO 2 geological capture and storage in the Lacq basin (Luc de MARLIAVE); - Clean coal: Air Liquide technology developments and industrial solutions (Nicolas PERRIN); - Clean combustion and CO 2 (Philippe PAELINCK); - CO 2 capture by freezing/defrosting at low temperatures (Denis CLODIC); - Questions; - Using the experience of a large corporation (ENDESA), to develop clean energy: coal (Laurent THABUSSOT); - Pathways to reduce CO 2

Neutron Capture Reactions on Fe and Ni Isotopes for the Astrophysical s-process

Energy Technology Data Exchange (ETDEWEB)

Lederer, C., E-mail: claudia.lederer@ed.ac.uk [University of Vienna, Faculty of Physics, 1090 Vienna (Austria); Johann-Wolfgang-Goethe Universität, 60438 Frankfurt (Germany); Giubrone, G. [Instituto de Física Corpuscular, CSIC-Universidad de Valencia, 46071 Valencia (Spain); Massimi, C. [Dipartimento di Fisica, Università di Bologna, and Sezione INFN di Bologna, 40100 Bologna (Italy); Žugec, P. [Department of Physics, Faculty of Science, University of Zagreb, 10002 Zagreb (Croatia); Barbagallo, M.; Colonna, N. [Istituto Nazionale di Fisica Nucleare, 70125 Bari (Italy); Domingo-Pardo, C. [Instituto de Física Corpuscular, CSIC-Universidad de Valencia, 46071 Valencia (Spain); Guerrero, C. [European Organization for Nuclear Research (CERN), CH-1211 Geneva (Switzerland); Gunsing, F. [Commissariat à l' Énergie Atomique (CEA) Saclay – Irfu, 91191 Gif-sur-Yvette (France); Käppeler, F. [Karlsruhe Institute of Technology, Campus Nord, Institut für Kernphysik, 76021 Karlsruhe (Germany); Tain, J.L. [Instituto de Física Corpuscular, CSIC-Universidad de Valencia, 46071 Valencia (Spain); Altstadt, S. [Johann-Wolfgang-Goethe Universität, 60438 Frankfurt (Germany); Andrzejewski, J. [Uniwersytet Łódzki, 90131 Lodz (Poland); Audouin, L. [Centre National de la Recherche Scientifique/IN2P3 – IPN, 91406 Orsay (France); Bécares, V. [Centro de Investigaciones Energeticas Medioambientales y Tecnológicas (CIEMAT), 28040 Madrid (Spain); Bečvář, F. [Faculty of Mathematics and Physics, Charles University, CZ-180 00 Prague (Czech Republic); and others

2014-06-15

Neutron capture cross sections in the keV neutron energy region are the key nuclear physics input to study the astrophysical slow neutron capture process. In the past years, a series of neutron capture cross section measurements has been performed at the neutron time-of-flight facility n{sub T}OF at CERN focussing on the Fe/Ni mass region. Recent results and future developments in the neutron time-of-flight technique are discussed.

Implementing Workload Postponing In Cloudsim to Maximize Renewable Energy Utilization

OpenAIRE

Enida Sheme; Neki Frashëri

2016-01-01

Green datacenters has become a major research area among researchers in academy and industry. One of the recent approaches getting higher attention is supplying datacenters with renewable sources of energy, leading to cleaner and more sustainable datacenters. However, this path poses new challenges. The main problem with existing renewable energy technologies is high variability, which means high fluctuation of available energy during different time periods on a day, month or year...

Captures of Boll Weevils (Coleoptera: Curculionidae) in Relation to Trap Orientation and Distance From Brush Lines.

Science.gov (United States)

Spurgeon, Dale W

2016-04-01

Eradication programs for the boll weevil (Anthonomus grandis grandis Boheman) rely on pheromone-baited traps to trigger insecticide treatments and monitor program progress. A key objective of monitoring in these programs is the timely detection of incipient weevil populations to limit or prevent re-infestation. Therefore, improvements in the effectiveness of trapping would enhance efforts to achieve and maintain eradication. Association of pheromone traps with woodlots and other prominent vegetation are reported to increase captures of weevils, but the spatial scale over which this effect occurs is unknown. The influences of trap distance (0, 10, and 20 m) and orientation (leeward or windward) to brush lines on boll weevil captures were examined during three noncropping seasons (October to February) in the Rio Grande Valley of Texas. Differences in numbers of captured weevils and in the probability of capture between traps at 10 or 20 m from brush, although often statistically significant, were generally small and variable. Variations in boll weevil population levels, wind directions, and wind speeds apparently contributed to this variability. In contrast, traps closely associated with brush (0 m) generally captured larger numbers of weevils, and offered a higher probability of weevil capture compared with traps away from brush. These increases in the probability of weevil capture were as high as 30%. Such increases in the ability of traps to detect low-level boll weevil populations indicate trap placement with respect to prominent vegetation is an important consideration in maximizing the effectiveness of trap-based monitoring for the boll weevil.