Horacio Coral-Enriquez; John Cortés-Romero; Germán A. Ramos
2013-01-01
This paper proposes an alternative robust observer-based linear control technique to maximize energy capture in a 4.8 MW horizontal-axis variable-speed wind turbine. The proposed strategy uses a generalized proportional integral (GPI) observer to reconstruct the aerodynamic torque in order to obtain a generator speed optimal trajectory. Then, a robust GPI observer-based controller supported by an active disturbance rejection (ADR) approach allows asymptotic tracking of the generator speed opt...
Horacio Coral-Enriquez
2013-01-01
Full Text Available This paper proposes an alternative robust observer-based linear control technique to maximize energy capture in a 4.8 MW horizontal-axis variable-speed wind turbine. The proposed strategy uses a generalized proportional integral (GPI observer to reconstruct the aerodynamic torque in order to obtain a generator speed optimal trajectory. Then, a robust GPI observer-based controller supported by an active disturbance rejection (ADR approach allows asymptotic tracking of the generator speed optimal trajectory. The proposed methodology controls the power coefficient, via the generator angular speed, towards an optimum point at which power coefficient is maximum. Several simulations (including an actuator fault are performed on a 4.8 MW wind turbine benchmark model in order to validate the proposed control strategy and to compare it to a classical controller. Simulation and validation results show that the proposed control strategy is effective in terms of power capture and robustness.
Energy, complexity and wealth maximization
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...
Algal Energy Conversion and Capture
Hazendonk, P.
2015-12-01
We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.
Measurable Maximal Energy and Minimal Time Interval
Dahab, Eiman Abou El
2014-01-01
The possibility of finding the measurable maximal energy and the minimal time interval is discussed in different quantum aspects. It is found that the linear generalized uncertainty principle (GUP) approach gives a non-physical result. Based on large scale Schwarzshild solution, the quadratic GUP approach is utilized. The calculations are performed at the shortest distance, at which the general relativity is assumed to be a good approximation for the quantum gravity and at larger distances, as well. It is found that both maximal energy and minimal time have the order of the Planck time. Then, the uncertainties in both quantities are accordingly bounded. Some physical insights are addressed. Also, the implications on the physics of early Universe and on quantized mass are outlined. The results are related to the existence of finite cosmological constant and minimum mass (mass quanta).
Maximal energy extraction under discrete diffusive exchange
Hay, M. J., E-mail: hay@princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States); Schiff, J. [Department of Mathematics, Bar-Ilan University, Ramat Gan 52900 (Israel); Fisch, N. J. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States); Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)
2015-10-15
Waves propagating through a bounded plasma can rearrange the densities of states in the six-dimensional velocity-configuration phase space. Depending on the rearrangement, the wave energy can either increase or decrease, with the difference taken up by the total plasma energy. In the case where the rearrangement is diffusive, only certain plasma states can be reached. It turns out that the set of reachable states through such diffusive rearrangements has been described in very different contexts. Building upon those descriptions, and making use of the fact that the plasma energy is a linear functional of the state densities, the maximal extractable energy under diffusive rearrangement can then be addressed through linear programming.
Maximal energy extraction under discrete diffusive exchange
Hay, Michael J; Fisch, Nathaniel J
2015-01-01
Waves propagating through a bounded plasma can rearrange the densities of states in the six-dimensional velocity-configuration phase space. Depending on the rearrangement, the wave energy can either increase or decrease, with the difference taken up by the total plasma energy. In the case where the rearrangement is diffusive, only certain plasma states can be reached. It turns out that the set of reachable states through such diffusive rearrangements has been described in very different contexts. Building upon those descriptions, and making use of the fact that the plasma energy is a linear functional of the state densities, the maximal extractable energy under diffusive rearrangement can then be addressed through linear programming.
Maximally reliable Markov chains under energy constraints.
Escola, Sean; Eisele, Michael; Miller, Kenneth; Paninski, Liam
2009-07-01
Signal-to-noise ratios in physical systems can be significantly degraded if the outputs of the systems are highly variable. Biological processes for which highly stereotyped signal generations are necessary features appear to have reduced their signal variabilities by employing multiple processing steps. To better understand why this multistep cascade structure might be desirable, we prove that the reliability of a signal generated by a multistate system with no memory (i.e., a Markov chain) is maximal if and only if the system topology is such that the process steps irreversibly through each state, with transition rates chosen such that an equal fraction of the total signal is generated in each state. Furthermore, our result indicates that by increasing the number of states, it is possible to arbitrarily increase the reliability of the system. In a physical system, however, an energy cost is associated with maintaining irreversible transitions, and this cost increases with the number of such transitions (i.e., the number of states). Thus, an infinite-length chain, which would be perfectly reliable, is infeasible. To model the effects of energy demands on the maximally reliable solution, we numerically optimize the topology under two distinct energy functions that penalize either irreversible transitions or incommunicability between states, respectively. In both cases, the solutions are essentially irreversible linear chains, but with upper bounds on the number of states set by the amount of available energy. We therefore conclude that a physical system for which signal reliability is important should employ a linear architecture, with the number of states (and thus the reliability) determined by the intrinsic energy constraints of the system.
Energy Band Calculations for Maximally Even Superlattices
Krantz, Richard; Byrd, Jason
2007-03-01
Superlattices are multiple-well, semiconductor heterostructures that can be described by one-dimensional potential wells separated by potential barriers. We refer to a distribution of wells and barriers based on the theory of maximally even sets as a maximally even superlattice. The prototypical example of a maximally even set is the distribution of white and black keys on a piano keyboard. Black keys may represent wells and the white keys represent barriers. As the number of wells and barriers increase, efficient and stable methods of calculation are necessary to study these structures. We have implemented a finite-element method using the discrete variable representation (FE-DVR) to calculate E versus k for these superlattices. Use of the FE-DVR method greatly reduces the amount of calculation necessary for the eigenvalue problem.
Maximizing energy transfer in vibrofluidized granular systems
Windows-Yule, C.R.K.; Rosato, A.D.; Parker, D.J.; Thornton, A.R.
2015-01-01
Using discrete particle simulations validated by experimental data acquired using the positron emission particle tracking technique, we study the efficiency of energy transfer from a vibrating wall to a system of discrete, macroscopic particles. We demonstrate that even for a fixed input energy from
Integral circulant graphs of prime power order with maximal energy
Sander, Jürgen W; 10.1016/j.laa.2011.05.039
2011-01-01
The energy of a graph is the sum of the moduli of the eigenvalues of its adjacency matrix. We study the energy of integral circulant graphs, also called gcd graphs, which can be characterized by their vertex count n and a set D of divisors of n in such a way that they have vertex set Zn and edge set {{a, b} : a, b in Zn; gcd(a - b, n) in D}. Using tools from convex optimization, we study the maximal energy among all integral circulant graphs of prime power order ps and varying divisor sets D. Our main result states that this maximal energy approximately lies between s(p - 1)p^(s-1) and twice this value. We construct suitable divisor sets for which the energy lies in this interval. We also characterize hyperenergetic integral circulant graphs of prime power order and exhibit an interesting topological property of their divisor sets.
Green Energy in New Construction: Maximize Energy Savings and Minimize Cost
Ventresca, Joseph
2010-01-01
People often use the term "green energy" to refer to alternative energy technologies. But green energy doesn't guarantee maximum energy savings at a minimum cost--a common misconception. For school business officials, green energy means getting the lowest energy bills for the lowest construction cost, which translates into maximizing green energy…
The maximal energy of classes of integral circulant graphs
Sander, Jürgen W
2012-01-01
The energy of a graph is the sum of the moduli of the eigenvalues of its adjacency matrix. We study the energy of integral circulant graphs, also called gcd graphs, which can be characterized by their vertex count $n$ and a set $\\cal D$ of divisors of $n$ in such a way that they have vertex set $\\mathbb{Z}_n$ and edge set ${{a,b}: a,b\\in\\mathbb{Z}_n, \\gcd(a-b,n)\\in {\\cal D}}$. For a fixed prime power $n=p^s$ and a fixed divisor set size $|{\\cal D}| =r$, we analyze the maximal energy among all matching integral circulant graphs. Let $p^{a_1} < p^{a_2} < ... < p^{a_r}$ be the elements of ${\\cal D}$. It turns out that the differences $d_i=a_{i+1}-a_{i}$ between the exponents of an energy maximal divisor set must satisfy certain balance conditions: (i) either all $d_i$ equal $q:=\\frac{s-1}{r-1}$, or at most the two differences $[q]$ and $[q+1]$ may occur; %(for a certain $d$ depending on $r$ and $s$) (ii) there are rules governing the sequence $d_1,...,d_{r-1}$ of consecutive differences. For particular ...
Optimal weight based on energy imbalance and utility maximization
Sun, Ruoyan
2016-01-01
This paper investigates the optimal weight for both male and female using energy imbalance and utility maximization. Based on the difference of energy intake and expenditure, we develop a state equation that reveals the weight gain from this energy gap. We construct an objective function considering food consumption, eating habits and survival rate to measure utility. Through applying mathematical tools from optimal control methods and qualitative theory of differential equations, we obtain some results. For both male and female, the optimal weight is larger than the physiologically optimal weight calculated by the Body Mass Index (BMI). We also study the corresponding trajectories to steady state weight respectively. Depending on the value of a few parameters, the steady state can either be a saddle point with a monotonic trajectory or a focus with dampened oscillations.
Maximizing Utilization of Energy from Crop By-products
Budi Haryanto
2014-03-01
Full Text Available The availability of crop by-products is huge during harvesting times as related to the vast agricultural land area; however, their utilization is still limited due to lack of knowledge and handling problem. Seasonal effect is obvious especially during wet season when high rainfall hinders proper management of crop by-products. Crop by-products are energy rich feedstuffs in the form of chemical substance such as cellulose and hemicellulose. The utilization of cellulose and hemicellulose as sources of energy can be maximized by the application of technologies to increase the digestibility. Cellulose is polymer of glucose while hemicellulose is polymer of xylose which both can be converted to volatile fatty acids by rumen microbial enzyme activities and subsequently used by the host animal as source of energy. In addition, cellulose and hemicellulose can also be used as substrates for bioethanol production leaving behind residual matter with higher concentration of protein which is also appropriate for ruminant feeds. The fat content of crop by-products such as those in rice bran and corn germ can be extracted for oil production that can be used for human consumption with concomitant production of high nutritive value of residues for ruminant feeds. The oil extraction technologies are available; however the high cost of ethanol and oil production should obtain high attention to make the technologies more applicable at farmers’ level.
Paracellular epithelial sodium transport maximizes energy efficiency in the kidney.
Pei, Lei; Solis, Glenn; Nguyen, Mien T X; Kamat, Nikhil; Magenheimer, Lynn; Zhuo, Min; Li, Jiahua; Curry, Joshua; McDonough, Alicia A; Fields, Timothy A; Welch, William J; Yu, Alan S L
2016-07-01
Efficient oxygen utilization in the kidney may be supported by paracellular epithelial transport, a form of passive diffusion that is driven by preexisting transepithelial electrochemical gradients. Claudins are tight-junction transmembrane proteins that act as paracellular ion channels in epithelial cells. In the proximal tubule (PT) of the kidney, claudin-2 mediates paracellular sodium reabsorption. Here, we used murine models to investigate the role of claudin-2 in maintaining energy efficiency in the kidney. We found that claudin-2-null mice conserve sodium to the same extent as WT mice, even during profound dietary sodium depletion, as a result of the upregulation of transcellular Na-K-2Cl transport activity in the thick ascending limb of Henle. We hypothesized that shifting sodium transport to transcellular pathways would lead to increased whole-kidney oxygen consumption. Indeed, compared with control animals, oxygen consumption in the kidneys of claudin-2-null mice was markedly increased, resulting in medullary hypoxia. Furthermore, tubular injury in kidneys subjected to bilateral renal ischemia-reperfusion injury was more severe in the absence of claudin-2. Our results indicate that paracellular transport in the PT is required for efficient utilization of oxygen in the service of sodium transport. We speculate that paracellular permeability may have evolved as a general strategy in epithelial tissues to maximize energy efficiency.
Capturing Waste Gas: Saves Energy, Lower Costs
None
2013-07-12
In June 2009, ArcelorMittal learned about the potential to receive a 50% cost-matching grant from the American Recovery and Reinvestment Act (ARRA) administered by the U.S. Department of Energy (DOE). ArcelorMittal applied for the competitive grant and, in November, received $31.6 million as a DOE cost-sharing award. By matching the federal funding, ArcelorMittal was able to construct a new, high efficiency Energy Recovery & Reuse 504 Boiler and supporting infrastructure.
Optimal Energy Management for a Smart Grid using Resource-Aware Utility Maximization
Abegaz, Brook W.; Mahajan, Satish M.; Negeri, Ebisa O.
2016-06-01
Heterogeneous energy prosumers are aggregated to form a smart grid based energy community managed by a central controller which could maximize their collective energy resource utilization. Using the central controller and distributed energy management systems, various mechanisms that harness the power profile of the energy community are developed for optimal, multi-objective energy management. The proposed mechanisms include resource-aware, multi-variable energy utility maximization objectives, namely: (1) maximizing the net green energy utilization, (2) maximizing the prosumers' level of comfortable, high quality power usage, and (3) maximizing the economic dispatch of energy storage units that minimize the net energy cost of the energy community. Moreover, an optimal energy management solution that combines the three objectives has been implemented by developing novel techniques of optimally flexible (un)certainty projection and appliance based pricing decomposition in an IBM ILOG CPLEX studio. A real-world, per-minute data from an energy community consisting of forty prosumers in Amsterdam, Netherlands is used. Results show that each of the proposed mechanisms yields significant increases in the aggregate energy resource utilization and welfare of prosumers as compared to traditional peak-power reduction methods. Furthermore, the multi-objective, resource-aware utility maximization approach leads to an optimal energy equilibrium and provides a sustainable energy management solution as verified by the Lagrangian method. The proposed resource-aware mechanisms could directly benefit emerging energy communities in the world to attain their energy resource utilization targets.
Energy Capture Optimization for an Adaptive Wave Energy Converter
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 f
Maximizing Cloud Providers Revenues via Energy Aware Allocation Policies
Mazzucco, Michele; Deters, Ralph
2011-01-01
Cloud providers, like Amazon, offer their data centers' computational and storage capacities for lease to paying customers. High electricity consumption, associated with running a data center, not only reflects on its carbon footprint, but also increases the costs of running the data center itself. This paper addresses the problem of maximizing the revenues of Cloud providers by trimming down their electricity costs. As a solution allocation policies which are based on the dynamic powering servers on and off are introduced and evaluated. The policies aim at satisfying the conflicting goals of maximizing the users' experience while minimizing the amount of consumed electricity. The results of numerical experiments and simulations are described, showing that the proposed scheme performs well under different traffic conditions.
Detecting energy dependent neutron capture distributions in a liquid scintillator
Balmer, Matthew J.I., E-mail: m.balmer@lancaster.ac.uk [Department of Engineering, Lancaster University, LA1 4YR (United Kingdom); Gamage, Kelum A.A. [Department of Engineering, Lancaster University, LA1 4YR (United Kingdom); Taylor, Graeme C. [Neutron Metrology Group, National Physical Laboratory, Teddington, TW11 0LW (United Kingdom)
2015-03-11
A novel technique is being developed to estimate the effective dose of a neutron field based on the distribution of neutron captures in a scintillator. Using Monte Carlo techniques, a number of monoenergetic neutron source energies and locations were modelled and their neutron capture response was recorded. Using back propagation Artificial Neural Networks (ANN) the energy and incident direction of the neutron field was predicted from the distribution of neutron captures within a {sup 6}Li-loaded liquid scintillator. Using this proposed technique, the effective dose of {sup 252}Cf, {sup 241}AmBe and {sup 241}AmLi neutron fields was estimated to within 30% for four perpendicular angles in the horizontal plane. Initial theoretical investigations show that this technique holds some promise for real-time estimation of the effective dose of a neutron field.
A low energy aqueous ammonia CO2 capture process
Gaspar, Jozsef; Waseem Arshad, Muhammad; Blaker, Eirik Ask
2014-01-01
The most pressing challenges regarding the use of ammonia for CO2 capture are the precipitation limitation and the energy penalty of solvent regeneration. Precipitation-free operation is a vital task since solids may cause the shutdown of the plant. Precipitation and slurry formation can be avoided...... by increasing temperature and L/G ratio but this leads to higher heat consumption, jeopardizing the economic feasibility. Here we developed, investigated, and optimized a novel CO2 capture process design using aqueous ammonia as solvent. The proposed configuration replaces the traditional stripper for solvent...... based CO2 capture with a thermal decomposition reactor. The overall energy penalty is reduced at the expense of introducing a solid handling section which consists of a saturation reactor, a crystallizer and a belt filter. The feasibility of the present approach is demonstrated by simulation. Flow...
Implementing Workload Postponing In Cloudsim to Maximize Renewable Energy Utilization
Enida Sheme
2016-08-01
Full Text Available 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. In our paper, we address the issue of better managing datacenter workload in order to achieve higher utilization of available renewable energy. We implement an algorithm in CloudSim simulator which decides to postpone or urgently run a specific job asking for datacenter resources, based on job’s deadline and available solar energy. The aim of this algorithm is to make workload energy consumption through 24 hours match as much as possible the solar energy availability in 24 hours. Two typical, clear and cloudy days, are taken in consideration for simulation. The results from our experiments show that, for the chosen workload model, jobs are better managed by postponing or urgently running them, in terms of leveraging available solar energy. This yields up to 17% higher utilization of daily solar energy.
Inventing a Better Way to Capture the Energy of Waves
2016-06-01
NREL's ocean energy research team's efforts to develop more robust and cost-effective wave energy converters have yielded a record of invention titled, 'Wave Energy Conversion Devices with Actuated Geometry.' This innovative wave device features a wave converter with controlled geometry that increases energy capture and prevents large waves from overloading the generator. The invention's control system actuates flaps that open and close depending on wave conditions. Better control of the wave forces acting on wave energy conversion devices provides a solution to one of wave energy's biggest challenges -- and could cut the cost of wave energy in half.
Study Pelamis system to capture energy of ocean wave
Gobato, Ricardo; Fedrigo, Desire Francine Gobato
2015-01-01
Over the years, energy has become vital for humans, enabling us to comfort, leisure, mobility and other factors. The quest for cheap energy sources, renewable and clean has grown in recent years, mainly for the reduction of effects that comes degrading nature, allowing scientists and engineers to search for new technologies. Many energy sources have been researched for proper funding where some stand out for their ease of obtaining, by other low cost and others by being renewable. The main objective of this work is to study one of these energy sources - wave energy, whose capture is still in development. This energy comes from the waves of the sea and is 100% renewable and with minimal environmental impact when compared to hydro, nuclear, coal, thermal, etc. The system studied here is the Pelamis system.
NWTC Aerodynamics Studies Improve Energy Capture and Lower Costs of Wind-Generated Electricity
2015-08-01
Researchers at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) have expanded wind turbine aerodynamic research from blade and rotor aerodynamics to wind plant and atmospheric inflow effects. The energy capture from wind plants is dependent on all of these aerodynamic interactions. Research at the NWTC is crucial to understanding how wind turbines function in large, multiple-row wind plants. These conditions impact the cumulative fatigue damage of turbine structural components that ultimately effect the useful lifetime of wind turbines. This work also is essential for understanding and maximizing turbine and wind plant energy production. Both turbine lifetime and wind plant energy production are key determinants of the cost of wind-generated electricity.
The effects of variable speed and drive train component efficiencies on wind turbine energy capture
Fingersh, L.J.; Robinson, M.C.
1998-05-01
A wind turbine rotor achieves optimal aerodynamic efficiency at a single tip-speed ratio (TSR). To maintain that optimal TSR and maximize energy capture in the stochastic wind environment, it is necessary to employ variable-speed operation. Conventional constant-speed wind turbines have, in the past, been converted into variable-speed turbines by attaching power electronics to the conventional induction generator and gearbox drive train. Such turbines have shown marginal, if any, improvement in energy capture over their constant-speed counterparts. These discrepancies have been shown to be the result of drive train components that are not optimized for variable-speed operation. Traditional drive trains and power electronic converters are designed to achieve maximum efficiency at full load and speed. However, the main energy producing winds operate the turbine at light load for long periods of time. Because of this, significant losses to efficiency occur. This investigation employs a quasi-static model to demonstrate the dramatic effect that component efficiency curves can have on overall annual energy capture.
Flow Structures and Energy Capture from an Oscillating Hydrofoil
Franck, Jennifer; Frank, Sarah; Mandre, Shreyas
2013-11-01
The flow surrounding an oscillating hydrofoil in a uniform freestream is computationally investigated for hydrokinetic energy capture. Simulations are performed on an elliptical hydrofoil using 2D Direct Numerical Simulation (DNS) for low Reynolds number and 3D Large-Eddy Simulations (LES) for high Reynolds number simulations at 80,000. A non-inertial reference frame is utilized for rigid-body motion of the hydrofoil, which is prescribed a sinusoidal motion in pitch and heave. The kinematic parameters are varied and the resulting flow features are correlated with positive or negative energy capture. In an effort to optimize the stroke, variations in the sinusoidal heave and pitch signals are systematically explored and analyzed for future closed-loop control.
Spin observables in deuteron proton radiative capture at intermediate energies
Mehmandoost-Khajeh-Dad, A. A.; Amir-Ahmadi, H. R.; Bacelar, J. C. S.; van den Berg, A. M.; Castelijns, R.; Deltuva, A.; van Garderen, E. D.; Glöckle, W.; Golak, J.; Kalantar-Nayestanaki, N.; Kamada, H.; Kiš, M.; Koohi-Fayegh-Dehkordi, R.; Löhner, H.; Mahjour-Shafiei, M.; Mardanpour, H.; Messchendorp, J. G.; Nogga, A.; Sauer, P.; Shende, S. V.; Skibinski, R.; Witała, H.; Wörtche, H. J.
2005-06-01
A radiative deuteron-proton capture experiment was carried out at KVI using polarized-deuteron beams at incident energies of 55, 66.5, and 90 MeV/nucleon. Vector and tensor-analyzing powers were obtained for a large angular range. The results are interpreted with the help of Faddeev calculations, which are based on modern two- and three-nucleon potentials. Our data are described well by the calculations, and disagree significantly with the observed tensor anomaly at RCNP.
Power maximization for pyroelectric, piezoelectric, and hybrid energy harvesting
Shaheen, Murtadha A.
The goal of this dissertation consists of improving the efficiency of energy harvesting using pyroelectric and piezoelectric materials in a system by the proper characterization of electrical parameters, widening frequency, and coupling of both effects with the appropriate parameters. A new simple stand-alone method of characterizing the impedance of a pyroelectric cell has been demonstrated. This method utilizes a Pyroelectric single pole low pass filter technique, PSLPF. Utilizing the properties of a PSLPF, where a known input voltage is applied and capacitance C p and resistance Rp can be calculated at a frequency of 1 mHz to 1 Hz. This method demonstrates that for pyroelectric materials the impedance depends on two major factors: average working temperature, and the heating rate. Design and implementation of a hybrid approach using multiple piezoelectric cantilevers is presented. This is done to achieve mechanical and electrical tuning, along with bandwidth widening. In addition, a hybrid tuning technique with an improved adjusting capacitor method was applied. An toroid inductor of 700 mH is shunted in to the load resistance and shunt capacitance. Results show an extended frequency range up to 12 resonance frequencies (300% improvement) with improved power up to 197%. Finally, a hybrid piezoelectric and pyroelectric system is designed and tested. Using a voltage doubler, circuit for rectifying and collecting pyroelectric and piezoelectric voltages individually is proposed. The investigation showed that the hybrid energy is possible using the voltage doubler circuit from two independent sources for pyroelectrictity and piezoelectricity due to marked differences of optimal performance.
Location Based Throughput Maximization Routing in Energy Constrained Mobile Ad-hoc Network
V. Sumathy
2006-01-01
Full Text Available In wireless Ad-hoc network, power consumption becomes an important issue due to limited battery power. One of the reasons for energy expenditure in this network is irregularly distributed node pattern, which impose large interference range in certain area. To maximize the lifetime of ad-hoc mobile network, the power consumption rate of each node must be evenly distributed and the over all transmission range of each node must be minimized. Our protocol, Location based throughput maximization routing in energy constrained Ad-hoc network finds routing paths, which maximize the lifetime of individual nodes and minimize the total transmission energy consumption. The life of the entire network is increased and the network throughput is also increased. The reliability of the path is also increased. Location based energy constrained routing finds the distance between the nodes. Based on the distance the transmission power required is calculated and dynamically reduces the total transmission energy.
The radiative proton capture on 16O at satrophysical energies
Dubovichenko, Sergey
2016-01-01
The possibility of description of the experimental data for the astrophysical S-factor of the proton radiative capture on 16O to the ground state of 17F was considered in the frame of the modified potential cluster model with forbidden states and classification of the states according to Young tableaux. It was shown that on the basis of the E1 transitions from the states of p16O scattering to the ground state of 17F in the p16O channel generally succeed to explain the value of measured cross sections at astrophysical energies.
Energy analysis of the cryogenic CO2 capture process based on Stirling coolers
Song, Chunfeng; Kitamura, Yutaka; Li, Shuhong
2014-01-01
In the existing coal-fired power plants, the energy penalty associated with CO2 capture process is an important challenge. For this reason, energy analysis has been widely used as a powerful tool to optimize the capture efficiency and reduce energy consumption. In our previous work, a Stirling cooler based cryogenic CO2 capture system was outlined. Process simulation and energy analysis of the system were undertaken in this research. The whole CO2 capture process is composed of three sections...
Is energy expenditure taken into account in human sub-maximal jumping?--A simulation study.
Vanrenterghem, Jos; Bobbert, Maarten F; Casius, L J Richard; De Clercq, Dirk
2008-02-01
This paper presents a simulation study that was conducted to investigate whether the stereotyped motion pattern observed in human sub-maximal jumping can be interpreted from the perspective of energy expenditure. Human sub-maximal vertical countermovement jumps were compared to jumps simulated with a forward dynamic musculo-skeletal model. This model consisted of four interconnected rigid segments, actuated by six Hill-type muscle actuators. The only independent input of the model was the stimulation of muscles as a function of time. This input was optimized using an objective function, in which targeting a specific sub-maximal height value was combined with minimizing the amount of muscle work produced. The characteristic changes in motion pattern observed in humans jumping to different target heights were reproduced by the model. As the target height was lowered, two major changes occurred in the motion pattern. First, the countermovement amplitude was reduced; this helped to save energy because of reduced dissipation and regeneration of energy in the contractile elements. Second, the contribution of rotation of the heavy proximal segments of the lower limbs to the vertical velocity of the centre of gravity at take-off was less; this helped to save energy because of reduced ineffective rotational energies at take-off. The simulations also revealed that, with the observed movement adaptations, muscle work was reduced through improved relative use of the muscle's elastic properties in sub-maximal jumping. According to the results of the simulations, the stereotyped motion pattern observed in sub-maximal jumping is consistent with the idea that in sub-maximal jumping, subjects are trying to achieve the targeted jump height with minimal energy expenditure.
Low Mass Printable Devices for Energy Capture, Storage, and Use
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
Harne, R. L.; Zhang, Chunlin; Li, Bing; Wang, K. W.
2016-07-01
Impulsive energies are abundant throughout the natural and built environments, for instance as stimulated by wind gusts, foot-steps, or vehicle-road interactions. In the interest of maximizing the sustainability of society's technological developments, one idea is to capture these high-amplitude and abrupt energies and convert them into usable electrical power such as for sensors which otherwise rely on less sustainable power supplies. In this spirit, the considerable sensitivity to impulse-type events previously uncovered for bistable oscillators has motivated recent experimental and numerical studies on the power generation performance of bistable vibration energy harvesters. To lead to an effective and efficient predictive tool and design guide, this research develops a new analytical approach to estimate the electroelastic response and power generation of a bistable energy harvester when excited by an impulse. Comparison with values determined by direct simulation of the governing equations shows that the analytically predicted net converted energies are very accurate for a wide range of impulse strengths. Extensive experimental investigations are undertaken to validate the analytical approach and it is seen that the predicted estimates of the impulsive energy conversion are in excellent agreement with the measurements, and the detailed structural dynamics are correctly reproduced. As a result, the analytical approach represents a significant leap forward in the understanding of how to effectively leverage bistable structures as energy harvesting devices and introduces new means to elucidate the transient and far-from-equilibrium dynamics of nonlinear systems more generally.
Maximizing the spectral and energy efficiency of ARQ with a fixed outage probability
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.
Digestive capacity and toxicity cause mixed diets in red knots that maximize energy intake rate
Oudman, Thomas; Onrust, Jeroen; de Fouw, Jimmy; Spaans, Bernard; Piersma, Theunis; van Gils, Jan A
Among energy-maximizing animals, preferences for different prey can be explained by ranking the prey according to their energetic content. However, diet choice also depends on characteristics of the predator, such as the need to ingest necessary nutrients and the constraints imposed by digestion and
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.
Power maximization of a point absorber wave energy converter using improved model predictive control
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.
Yanjie Dong
2013-01-01
Full Text Available The capacity of Multiple Input Multiple Output (MIMO system is highly related to the number of active antennas. But as the active antenna number increases, the MIMO system will consume more energy. To maximize the energy efficiency of MIMO system, we propose an antenna selection scheme which can maximize the energy efficiency of BS cluster. In the scheme, ergodic energy efficiency is derived according to large scale channel state information (CSI. Based on this ergodic energy efficiency, we introduce a cost function varied with the number of antennas, in which the effect to the energy efficiency of both the serving BS and the neighbor BS is considered. With this function, we can transform the whole system optimization problem to a sectional optimization problem and obtain a suboptimal antenna set using a heuristic algorithm. Simulation results verify that the proposed approach performs better than the comparison schemes in terms of network energy efficiency and achieves 98% network energy efficiency of the centralized antenna selection scheme. Besides, since the proposed scheme does not need the complete CSI of the neighbor BS, it can effectively reduce the signaling overhead.
A solid solution to a conjecture on the maximal energy of bipartite bicyclic graphs
Huo, Bofeng; Li, Xueliang; Shi, Yongtang
2011-01-01
The energy of a simple graph $G$, denoted by $E(G)$, is defined as the sum of the absolute values of all eigenvalues of its adjacency matrix. Let $C_n$ denote the cycle of order $n$ and $P^{6,6}_n$ the graph obtained from joining two cycles $C_6$ by a path $P_{n-12}$ with its two leaves. Let $\\mathscr{B}_n$ denote the class of all bipartite bicyclic graphs but not the graph $R_{a,b}$, which is obtained from joining two cycles $C_a$ and $C_b$ ($a, b\\geq 10$ and $a \\equiv b\\equiv 2\\, (\\,\\textmd{mod}\\, 4)$) by an edge. In [I. Gutman, D. Vidovi\\'{c}, Quest for molecular graphs with maximal energy: a computer experiment, {\\it J. Chem. Inf. Sci.} {\\bf41}(2001), 1002--1005], Gutman and Vidovi\\'{c} conjectured that the bicyclic graph with maximal energy is $P^{6,6}_n$, for $n=14$ and $n\\geq 16$. In [X. Li, J. Zhang, On bicyclic graphs with maximal energy, {\\it Linear Algebra Appl.} {\\bf427}(2007), 87--98], Li and Zhang showed that the conjecture is true for graphs in the class $\\mathscr{B}_n$. However, they could not...
Zhang, Chi; Wang, Long-Fei; Yue, Yuan; Yu, Lian-Chun
2015-01-01
Energy efficiency is closely related to the evolution of biological systems and is important to their information processing. In this paper, we calculated the excitation probability of a simple model of a bistable biological unit in response to pulsatile inputs, and its spontaneous excitation rate due to noise perturbation. Then we analytically calculated the mutual information, energy cost, and energy efficiency of an array of these bistable units. We found that the optimal number of units could maximize this array's energy efficiency in encoding pulse inputs, which depends on the fixed energy cost. We conclude that demand for energy efficiency in biological systems may strongly influence the size of these systems under the pressure of natural selection.
Herrmann, Michael
2010-01-01
We study focussing discrete nonlinear Schr\\"{o}dinger equations and present a new variational existence proof for homoclinic standing waves (bright solitons). Our approach relies on the constrained maximization of an energy functional and provides the existence of two one-parameter families of waves with unimodal and even profile function for a wide class of nonlinearities. Finally, we illustrate our results by numerical simulations.
Effect of red bull energy drink on auditory reaction time and maximal voluntary contraction.
Goel, Vartika; Manjunatha, S; Pai, Kirtana M
2014-01-01
The use of "Energy Drinks" (ED) is increasing in India. Students specially use these drinks to rejuvenate after strenuous exercises or as a stimulant during exam times. The most common ingredient in EDs is caffeine and a popular ED available and commonly used is Red Bull, containing 80 mg of caffeine in 250 ml bottle. The primary aim of this study was to investigate the effects of Red Bull energy drink on Auditory reaction time and Maximal voluntary contraction. A homogeneous group containing twenty medical students (10 males, 10 females) participated in a crossover study in which they were randomized to supplement with Red Bull (2 mg/kg body weight of caffeine) or isoenergetic isovolumetric noncaffeinated control drink (a combination of Appy Fizz, Cranberry juice and soda) separated by 7 days. Maximal voluntary contraction (MVC) was recorded as the highest of the 3 values of maximal isometric force generated from the dominant hand using hand grip dynamometer (Biopac systems). Auditory reaction time (ART) was the average of 10 values of the time interval between the click sound and response by pressing the push button using hand held switch (Biopac systems). The energy and control drinks after one hour of consumption significantly reduced the Auditory reaction time in males (ED 232 ± 59 Vs 204 ± 34 s and Control 223 ± 57 Vs 210 ± 51 s; p caffeine in the beneficial effect seen after the drinks.
Capture of Heat Energy from Diesel Engine Exhaust
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
Throughput Maximization for Sensor-Aided Cognitive Radio Networks with Continuous Energy Arrivals.
Nguyen, Thanh-Tung; Koo, Insoo
2015-11-27
We consider a Sensor-Aided Cognitive Radio Network (SACRN) in which sensors capable of harvesting energy are distributed throughout the network to support secondary transmitters for sensing licensed channels in order to improve both energy and spectral efficiency. Harvesting ambient energy is one of the most promising solutions to mitigate energy deficiency, prolong device lifetime, and partly reduce the battery size of devices. So far, many works related to SACRN have considered single secondary users capable of harvesting energy in whole slot as well as short-term throughput. In the paper, we consider two types of energy harvesting sensor nodes (EHSN): Type-I sensor nodes will harvest ambient energy in whole slot duration, whereas type-II sensor nodes will only harvest energy after carrying out spectrum sensing. In the paper, we also investigate long-term throughput in the scheduling window, and formulate the throughput maximization problem by considering energy-neutral operation conditions of type-I and -II sensors and the target detection probability. Through simulations, it is shown that the sensing energy consumption of all sensor nodes can be efficiently managed with the proposed scheme to achieve optimal long-term throughput in the window.
The exact maximal energy of integral circulant graphs with prime power order
Sander, J W
2011-01-01
The energy of a graph was introduced by {\\sc Gutman} in 1978 as the sum of the absolute values of the eigenvalues of its adjacency matrix. We study the energy of integral circulant graphs, also called gcd graphs, which can be characterized by their vertex count $n$ and a set $\\cal D$ of divisors of $n$ in such a way that they have vertex set $\\mathbb{Z}/n\\mathbb{Z}$ and edge set $\\{\\{a,b\\}:\\, a,b\\in\\mathbb{Z}/n\\mathbb{Z},\\, \\gcd(a-b,n)\\in {\\cal D}\\}$. Given an arbitrary prime power $p^s$, we determine all divisor sets maximising the energy of an integral circulant graph of order $p^s$. This enables us to compute the maximal energy $\\Emax{p^s}$ among all integral circulant graphs of order $p^s$.
Energy Efficiency Maximization for WSNs with Simultaneous Wireless Information and Power Transfer.
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.
Maximizing Residential Energy Savings: Net Zero Energy House (ZEH) Technology Pathways
Anderson, R.; Roberts, D.
2008-11-01
To meet current U.S. Department of Energy zero-energy home performance goals, new technologies and solutions must increase whole-house efficiency savings by an additional 40% relative to those provided by best available components and systems.
Worst-Case Energy Efficiency Maximization in a 5G Massive MIMO-NOMA System.
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.
Maximization of Energy Efficiency in Wireless ad hoc and Sensor Networks With SERENA
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.
Bison distribution under conflicting foraging strategies: site fidelity vs. energy maximization.
Merkle, Jerod A; Cherry, Seth G; Fortin, Daniel
2015-07-01
Foraging strategies based on site fidelity and maximization of energy intake rate are two adaptive forces shaping animal behavior. Whereas these strategies can both be evolutionarily stable, they predict conflicting optimal behaviors when population abundance is in decline. In such a case, foragers employing an energy-maximizing strategy should reduce their use of low-quality patches as interference competition becomes less intense for high-quality patches. Foragers using a site fidelity strategy, however, should continue to use familiar patches. Because natural fluctuations in population abundance provide the only non-manipulative opportunity to evaluate adaptation to these evolutionary forces, few studies have examined these foraging strategies simultaneously. Using abundance and space use data from a free-ranging bison (Bison bison) population living in a meadow-forest matrix in Prince Albert National Park, Canada, we determined how individuals balance the trade-off between site fidelity and energy-maximizing patch choice strategies with respect to changes in population abundance. From 1996 to 2005, bison abundance increased from 225 to 475 and then decreased to 225 by 2013. During the period of population increase, population range size increased. This expansion involved the addition of relatively less profitable areas and patches, leading to a decrease in the mean expected profitability of the range. Yet, during the period of population decline, we detected neither a subsequent retraction in population range size nor an increase in mean expected profitability of the range. Further, patch selection models. during the population decline indicated that, as density decreased, bison portrayed stronger fidelity to previously visited meadows, but no increase in selection strength for profitable meadows. Our analysis reveals that an energy-maximizing patch choice strategy alone cannot explain the distribution ofindividuals and populations, and site fidelity is an
Luo, Hanjiang; Guo, Zhongwen; Wu, Kaishun; Hong, Feng; Feng, Yuan
2009-01-01
Underwater acoustic sensor networks (UWA-SNs) are envisioned to perform monitoring tasks over the large portion of the world covered by oceans. Due to economics and the large area of the ocean, UWA-SNs are mainly sparsely deployed networks nowadays. The limited battery resources is a big challenge for the deployment of such long-term sensor networks. Unbalanced battery energy consumption will lead to early energy depletion of nodes, which partitions the whole networks and impairs the integrity of the monitoring datasets or even results in the collapse of the entire networks. On the contrary, balanced energy dissipation of nodes can prolong the lifetime of such networks. In this paper, we focus on the energy balance dissipation problem of two types of sparsely deployed UWA-SNs: underwater moored monitoring systems and sparsely deployed two-dimensional UWA-SNs. We first analyze the reasons of unbalanced energy consumption in such networks, then we propose two energy balanced strategies to maximize the lifetime of networks both in shallow and deep water. Finally, we evaluate our methods by simulations and the results show that the two strategies can achieve balanced energy consumption per node while at the same time prolong the networks lifetime.
Hanjiang Luo
2009-08-01
Full Text Available Underwater acoustic sensor networks (UWA-SNs are envisioned to perform monitoring tasks over the large portion of the world covered by oceans. Due to economics and the large area of the ocean, UWA-SNs are mainly sparsely deployed networks nowadays. The limited battery resources is a big challenge for the deployment of such long-term sensor networks. Unbalanced battery energy consumption will lead to early energy depletion of nodes, which partitions the whole networks and impairs the integrity of the monitoring datasets or even results in the collapse of the entire networks. On the contrary, balanced energy dissipation of nodes can prolong the lifetime of such networks. In this paper, we focus on the energy balance dissipation problem of two types of sparsely deployed UWA-SNs: underwater moored monitoring systems and sparsely deployed two-dimensional UWA-SNs. We first analyze the reasons of unbalanced energy consumption in such networks, then we propose two energy balanced strategies to maximize the lifetime of networks both in shallow and deep water. Finally, we evaluate our methods by simulations and the results show that the two strategies can achieve balanced energy consumption per node while at the same time prolong the networks lifetime.
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.
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.
More Energy-Efficient CO2 Capture from IGCC GE Flue Gases
Rakpong Peampermpool
2017-03-01
Full Text Available Carbon dioxide (CO2 emissions are one of the main reasons for the increase in greenhouse gasses in the earth’s atmosphere and carbon capture and sequestration (CCS is known as an effective method to reduce CO2 emissions on a larger scale, such as for fossil energy utilization systems. In this paper, the feasibility of capturing CO2 using cryogenic liquefaction and improving the capture rate by expansion will be discussed. The main aim was to design an energy-saving scheme for an IGCC (integrated gasification combined cycle power plant with CO2 cryogenic liquefaction capture. The experimental results provided by the authors, using the feed gas specification of a 740 MW IGCC General Electric (GE combustion power plant, demonstrated that using an orifice for further expanding the vent gas after cryogenic capture from 57 bar to 24 bar gave an experimentally observed capture rate up to 65%. The energy-saving scheme can improve the overall CO2 capture rate, and hence save energy. The capture process has also been simulated using Aspen HYSYS simulation software to evaluate its energy penalty. The results show that a 92% overall capture rate can be achieved by using an orifice.
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.
Wei, Wei; Wang, Jianhui; Mei, Shengwei
2016-09-23
In this paper, we consider dispatchability as the set of all admissible nodal wind power injections that will not cause infeasibility in real-time dispatch (RTD). Our work reveals that the dispatchability of the affine policy based RTD (AF-RTD) is a polytope whose coefficients are linear functions of the generation schedule and the gain matrix of affine policy. Two mathematical formulations of the dispatchability maximized energy and reserve dispatch (DM-ERD) are proposed. The first one maximizes the distance from the forecast to the boundaries of the dispatchability polytope subject to the available production cost or reserve cost. Provided the forecast value and variance of wind power, the generalized Gauss inequality (GGI) is adopted to evaluate the probability of infeasible RTD without the exact probability distribution of wind power. Combining the first formulation and the GGI approach, the second one minimizes the total cost subject to a desired reliability level through dispatchability maximization. Efficient convex optimization based algorithms are developed to solve these two models. Different from the conventional robust optimization method, our model does not rely on the specific uncertainty set of wind generation and directly optimizes the uncertainty accommodation capability of the power system. The proposed method is also compared with the affine policy based robust energy and reserve dispatch (AR-ERD). Case studies on the PJM 5-bus system illustrate the proposed concept and method. Experiments on the IEEE 118-bus system demonstrate the applicability of our method on moderate sized systems and its scalability to large dimensional uncertainty.
Energy Efficiency and SINR Maximization Beamformers for Spectrum Sharing With Sensing Information
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.
Du, Sijun; Jia, Yu; Seshia, Ashwin
2015-12-01
A resonant vibration energy harvester typically comprises of a clamped anchor and a vibrating shuttle with a proof mass. Piezoelectric materials are embedded in locations of high strain in order to transduce mechanical deformation into electric charge. Conventional design for piezoelectric vibration energy harvesters (PVEH) usually utilizes piezoelectric material and metal electrode layers covering the entire surface area of the cantilever with no consideration provided to examining the trade-off involved with respect to maximizing output power. This paper reports on the theory and experimental verification underpinning optimization of the active electrode area of a cantilevered PVEH in order to maximize output power. The analytical formulation utilizes Euler-Bernoulli beam theory to model the mechanical response of the cantilever. The expression for output power is reduced to a fifth order polynomial expression as a function of the electrode area. The maximum output power corresponds to the case when 44% area of the cantilever is covered by electrode metal. Experimental results are also provided to verify the theory.
Meinrenken, Christoph
2015-03-01
Capture of CO2, whether from a flue gas source (PCC) or from distributed sources via ambient air (DAC), is a key enabling technology to provide carbon for sustainable synthetic energy carriers such as solar fuels. Based on thermodynamic minimum considerations, DAC is often expected to require about 3 times more energy (per ton CO2 captured) than PCC because CO2 in ambient air is more dilute. Here, we calculate the energy required for a humidity swing-based DAC installation that uses an anionic exchange resin as sorbent. The calculation uses recently measured equilibrium CO2 loadings of the sorbent as function of partial CO2 pressure, temperature, and humidity. We calculate the installation's electricity consumption to be about 45 kJ per mole of pure CO2 at 1 bar (scenario-dependent). Furthermore, we estimate the amount of heat provided by ambient air and thus provide context of the overall energy and entropy balance and thermodynamic minimum views. The electricity consumption is competitive with typical parasitic loads of PCC-equipped coal-fired power plants (40-50 kJ per mole at same pressure) and significantly lower than predicted for other DAC installations such as Na(OH) sorbent-based systems. Our analyses elucidate why DAC is not always more energy-intensive that PCC, thus alleviating often cited concerns of significant cost impediments. Financial support by ABB for research presented herein is gratefully acknowledged.
A study to maximize the crash energy absorption efficiency within the limits of crash space
Kim, Bae Young; Jeong, Choong Min; Suh, Myung Won [Sungkyunkwan University, Suwon (Korea, Republic of); Kim, Si Woo [Korea Automobile Testing and Research Institute, Hwaseong (Korea, Republic of)
2012-04-15
The design of an engine room is important to protect the passenger from a crash impact by improving the absorption of the crash impact energy. The side member in the engine room absorbs most of the crash impact energy when the vehicle experiences a frontal crash. The side member is of two types: hat and 'U.' Analysis of the extent of energy absorption and the mechanism of the side member are necessary through a collapse mode in various load conditions. In this study, the design of experiments was used for evaluating the characteristics of the absorption of crash energy by side members through design variables. First, crash analysis was performed by experiment number extracted from the design of the experiment. Then, using the results of crash analysis, multiple regressions were conducted and sensitivity analysis performed for each design variable. Finally, the optimum design was developed for maximizing the absorption energy per unit weight considering various boundary conditions. In the present study, as a basic step for modeling the fatigue behavior of an extruded Al alloy cylinder, the fatigue crack growth data of the alloy was collected in two orientations. Microstructural analysis revealed that the material had recrystallized grains and clusters of constituent particles aligned in the direction of extrusion. Fatigue life of the samples revealed a shorter fatigue life representing a higher fatigue crack growth rate in the transverse direction.
Effect of energy expenditure and training status on leptin response to sub-maximal cycling.
Bouassida, Anissa; Chatard, Jean-Claude; Chamari, Karim; Zaouali, Monia; Feki, Youssef; Gharbi, Najoua; Zbidi, Abdelkarim; Tabka, Zouhaïr
2009-01-01
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 energy
Process simulation of oxy-combustion for maximization of energy output using ASPEN plus
Subhodeep Banerjee, Xiao Zhang, Suraj K. Puvvada, Ramesh K. Agarwal
2014-01-01
Full Text Available Oxy-fuel combustion is a next-generation combustion technology that shows promise to address the need of low-cost carbon capture from fossil fueled power plants. Oxy-fuel combustion requires expensive pre-processing in an air separation unit to separate pure oxygen from air for the combustion process, which reduces the overall efficiency of the process. This paper employs ASPEN Plus process simulation software to model a simple oxy-fuel combustor and investigates the effect of various parameters on the energy output. The composition of the flue gas is carefully examined. The results of this study provide a starting point for optimized oxy-fuel combustion operation for maximum energy output, which will be crucial for future deployment of oxy-fuel combustion technology.
Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.
2012-01-01
Future integrated gasification combined cycle (IGCC) power plants with CO{sub 2} capture will face stricter operational and environmental constraints. Accurate values of relevant states/outputs/disturbances are needed to satisfy these constraints and to maximize the operational efficiency. Unfortunately, a number of these process variables cannot be measured while a number of them can be measured, but have low precision, reliability, or signal-to-noise ratio. In this work, a sensor placement (SP) algorithm is developed for optimal selection of sensor location, number, and type that can maximize the plant efficiency and result in a desired precision of the relevant measured/unmeasured states. In this work, an SP algorithm is developed for an selective, dual-stage Selexol-based acid gas removal (AGR) unit for an IGCC plant with pre-combustion CO{sub 2} capture. A comprehensive nonlinear dynamic model of the AGR unit is developed in Aspen Plus Dynamics® (APD) and used to generate a linear state-space model that is used in the SP algorithm. The SP algorithm is developed with the assumption that an optimal Kalman filter will be implemented in the plant for state and disturbance estimation. The algorithm is developed assuming steady-state Kalman filtering and steady-state operation of the plant. The control system is considered to operate based on the estimated states and thereby, captures the effects of the SP algorithm on the overall plant efficiency. The optimization problem is solved by Genetic Algorithm (GA) considering both linear and nonlinear equality and inequality constraints. Due to the very large number of candidate sets available for sensor placement and because of the long time that it takes to solve the constrained optimization problem that includes more than 1000 states, solution of this problem is computationally expensive. For reducing the computation time, parallel computing is performed using the Distributed Computing Server (DCS®) and the Parallel
Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.
2012-01-01
Future integrated gasification combined cycle (IGCC) power plants with CO{sub 2} capture will face stricter operational and environmental constraints. Accurate values of relevant states/outputs/disturbances are needed to satisfy these constraints and to maximize the operational efficiency. Unfortunately, a number of these process variables cannot be measured while a number of them can be measured, but have low precision, reliability, or signal-to-noise ratio. In this work, a sensor placement (SP) algorithm is developed for optimal selection of sensor location, number, and type that can maximize the plant efficiency and result in a desired precision of the relevant measured/unmeasured states. In this work, an SP algorithm is developed for an selective, dual-stage Selexol-based acid gas removal (AGR) unit for an IGCC plant with pre-combustion CO{sub 2} capture. A comprehensive nonlinear dynamic model of the AGR unit is developed in Aspen Plus Dynamics® (APD) and used to generate a linear state-space model that is used in the SP algorithm. The SP algorithm is developed with the assumption that an optimal Kalman filter will be implemented in the plant for state and disturbance estimation. The algorithm is developed assuming steady-state Kalman filtering and steady-state operation of the plant. The control system is considered to operate based on the estimated states and thereby, captures the effects of the SP algorithm on the overall plant efficiency. The optimization problem is solved by Genetic Algorithm (GA) considering both linear and nonlinear equality and inequality constraints. Due to the very large number of candidate sets available for sensor placement and because of the long time that it takes to solve the constrained optimization problem that includes more than 1000 states, solution of this problem is computationally expensive. For reducing the computation time, parallel computing is performed using the Distributed Computing Server (DCS®) and the Parallel
Determination and production of an optimal neutron energy spectrum for boron neutron capture therapy
Bleuel, Darren Leo
An accelerator-based neutron irradiation facility employing an electrostatic quadrupole (ESQ) accelerator for Boron Neutron Capture Therapy (BNCT) has been proposed at Lawrence Berkeley National Laboratory. In this dissertation, the properties of an ideal neutron beam for delivering a maximized dose to a glioblastoma multiforme tumor in a reasonable time while minimizing the dose to healthy tissue is examined. A variety of materials, beam shaping assemblies, and neutron sources were considered to deliver a neutron spectrum as close to the calculated idealized spectrum as possible. Several optimization studies were performed to determine the best proton energy and moderator material to maximize the efficacy of an accelerator-based BNCT facility utilizing the 7Li(p,n)7Be reaction as a neutron source. A new, faster method of performing such an optimization was developed, known as the "Ubertally" method, in which data from a single Monte Carlo simulation is reweighted to produce results for any neutron spatial, energy and angular source distribution. Results were confirmed experimentally at Lawrence Berkeley National Laboratory's 88″ cyclotron. Thermal fluxes in this experiment were found to be approximately 30% lower than expected, but the depth-dose profile was confirmed to within 8% maximum deviation. A final beam shaping assembly is then recommended. Utilizing a material known as Fluental as a moderating material, deep-seated tumor doses 50% higher than that delivered by clinical trials at the Brookhaven Medical Research Reactor (BMRR) are predicted. The final recommended design should contain a 37 cm thickness of Fluental(TM) moderator, a 1--2 cm gamma shield, an Al2O3 reflector, a V-shaped aluminum-backed or copper-backed source with heavy water cooling, and a 13 cm lithiated polyethylene delimiter. This design would be operated at 2.4 MeV proton energy at 20 mA to conduct treatments in less than an hour and a half. However, this design may be easily altered
EFFECT OF ENERGY EXPENDITURE AND TRAINING STATUS ON LEPTIN RESPONSE TO SUB-MAXIMAL CYCLING
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
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
On Maximizing the Lifetime of Wireless Sensor Networks by Optimally Assigning Energy Supplies
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.
Rosenkilde Larsen, Mads; Morville, Thomas; Riis Andersen, Peter
2015-01-01
.02) after cycling. CONCLUSIONS: Older male cyclists sustained near-maximal rates of EE during prolonged cycling but were unable to upregulate EI to maintain energy balance. Despite the presence of increased motivation to eat, a more profound counteracting physiologic stimulus inhibiting increases in EI...
PROFIT MAXIMIZATION AND OPTIMAL SIZING OF RENEWABLE ENERGY SOURCES IN A HYBRID SYSTEM
YAJVENDER PAL VERMA
2010-09-01
Full Text Available The renewable energy sources wind, solar etc. have become very essential and important in the generation mix as a result of rising energy demand and environmental reasons. In addition tax is being imposed on high carbon emission. But the uncertainty and variability associated with renewable such as wind may result in economical andtechnical problems in the power system. In order to compensate wind intermittency, generation resources such as gas plant, pumped storage unit etc. are employed due to their lesser start up time, lower operating cost and good ramping capabilities. This paper proposes a model which investigates the combined operation of thermal, wind andpumped storage units for the profit maximization in varying wind, load, and price scenarios. The optimal size of the pumped storage unit to be used has been obtained after putting the system to different operating conditions such as varying wind power and load demand, imposing tax on carbon emission and varying ramping limits etc. The model has been applied on IEEE-30 bus test data and satisfactory results have been obtained for optimal hybrid systemoperation.
Understanding Low Energy Gamma Emission from Fission and Capture with DANCE
Wilburn, Grey; Couture, Aaron; Mosby, Shea
2012-10-01
Los Alamos National Laboratory's Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 barium fluoride (BaF2) detectors in a 4π array used to study cross-section measurements from neutron capture reactions. Further, recent studies have taken advantage of DANCE to study the gamma emission from fission, which is not well characterized. Neutron capture is studied because of its relevance to nuclear astrophysics (almost all elements heavier than iron are formed via neutron capture) and nuclear energy, where neutron capture is a poison in the reactor. Gamma ray cascades following neutron capture and fission include photons with energies between 100 keV and 10 MeV. DANCE uses a ^6LiH sphere to attenuate scattered neutrons, the primary background in DANCE. Unfortunately, it also attenuates low energy gamma rays. In order to quantify this effect and validate simulations, direct measurements of low energy gammas were made with a high purity germanium (HPGe) crystal. HPGe's allow for high resolution measurements of low energy gamma rays that are not possible using the BaF2 crystals. The results and their agreement with simulations will be discussed.
Contribution of neutron-capture reactions in energy release in the fuel core of BN-600
Bahdanovich, R. B.; Romanenko, V. I.; Tikhomirov, G. V.
2017-01-01
The use of modern computing powers and calculation methods allows to get closer to reality results of modelling, as well as to explore areas inaccessible to the experiment. Until now, the calculation of the energy released from the capture of neutrons in the reactor core has been given little attention. The method for calculation of the effective energy release components in a nuclear reactor allows to specify the values used by engineering programs for capture energy release in fast reactors. The paper presents improved method and the results of calculation of three models of the reactor BN-600. It is shown that the contribution of capture energy release in effective energy release for fresh fuel is equal to 4%, which is more than for VVER reactors. During the calculation we created a simple calculation model of the fast reactor, considering its features.
Economic viability of a simple tidal stream energy capture device
NONE
2007-02-15
This tidal stream energy project has compared the overall economics of two horizontal axis tidal turbine devices: a fixed pitch, bidirectional, variable speed turbine generator device with a variable pitch, variable speed turbine generator device that rotates to face into the tidal flow. The project has established, theoretically, the extent to which the loss in energy conversion efficiency of the simpler to construct fixed pitch device is counterbalanced by a reduction in capital and Operation and Maintenance (OM) costs and whether the system is technically feasible and sufficiently economic to warrant further development. The conclusion is that the simple fixed pitch, bi-directional device is competitive on a life cycle cost basis and worthy of further consideration. This collaborative project involves the Wolfson Unit for Marine Technology and Industrial Aerodynamics (WUMTIA) of the University of Southampton, ALSTOM Power Ltd - Technology Centre and LOG+1. While not party to the grant arrangements with the DTI, E.ON UK Power Technology Ltd. on behalf of E.ON UK Renewables Developments Ltd., has provided a utility perspective and Converteam Ltd has provided information on generators and power conversion aspects. The agreed project scope was limited to horizontal axis tidal turbines (HATT), and did not include consideration of alternative approaches such as vertical axis turbines or oscillating hydrofoil systems. The (OM) element of the lifetime cost of a tidal stream concept may well be greater than the significant contribution of O and M costs to the cost per kWh anticipated for offshore wind energy, and be a major determinant in the commercial viability of tidal stream energy. A commercially successful HATT system will need a very high level of reliability and accessibility, with the longest periods between routine maintenance inspections consistent with optimum whole-life economies. The premise is that the lowest capital and operating costs are more likely to
Proton-deuteron radiative capture cross sections at intermediate energies
Mehmandoost-Khajeh-Dad, A A; Amir-Ahmadi, H R; Bacelar, J C S; Berg, A M van den; Castelijns, R; van Garderen, E D; Kalantar-Nayestanaki, N; Kiš, M; Löhner, H; Messchendorp, J G; Wörtche, H J
2011-01-01
Differential cross sections of the reaction $p(d,^3{\\rm He})\\gamma$ have been measured at deuteron laboratory energies of 110, 133 and 180 MeV. The data were obtained with a coincidence setup measuring both the outgoing $^3$He and the photon. The data are compared with modern calculations including all possible meson-exchange currents and two- and three- nucleon forces in the potential. The data clearly show a preference for one of the models, although the shape of the angular distribution cannot be reproduced by any of the presented models.
Process simulation and maximization of energy output in chemical-looping combustion using ASPEN plus
Xiao Zhang, Subhodeep Banerjee, Ling Zhou, Ramesh Agarwal
2015-01-01
Full Text Available Chemical-looping combustion (CLC is currently considered as a leading technology for reducing the economic cost of CO2 capture. In this paper, several process simulations of chemical-looping combustion are conducted using the ASPEN Plus software. The entire CLC process from the beginning of coal gasification to the reduction and oxidation of the oxygen carrier is modeled and validated against experimental data. The energy balance of each major component of the CLC process, e.g., the fuel and air reactors and air/flue gas heat exchangers is examined. Different air flow rates and oxygen carrier feeding rates are used in the simulations to obtain the optimum ratio of coal, air, and oxygen carrier that produces the maximum power. Two scaled-up simulations are also conducted to investigate the influence of increase in coal feeding on power generation. It is demonstrated that the optimum ratio of coal, air supply, and oxygen carrier for maximum power generation remains valid for scaled-up cases with substantially larger coal feeding rates; the maximum power generation scales up linearly by using the process simulation models in ASPEN Plus. The energy output from four different types of coals is compared, and the optimum ratio of coal, air supply and oxygen carrier for maximum power generation for each type of coal is determined.
Nuclear halo effect on nucleon capture reaction rates at stellar energies
Liu Zu-Hua; Zhou Hong-Yu
2005-01-01
The capture cross sections at stellar energies are very difficult to measure directly. Hence, data are usually evaluated by using indirect methods or extrapolations from the experimental data obtained at the lowest possible energies. The asymptotic normalization coefficient (ANC) approach of the transfer reactions provides a reliable way for the determination of the capture cross sections at stellar energies. By virtue of its reliability, we have calculated the capture cross sections of the 10Be(n,γ)11Be reaction by using nuclear ANC method. 11Be is a well-known neutron halo nucleus with two weakly bound states. As a typical example, we have shown that the radiative cross sections for a nucleon captured into a halo state are obviously enhanced. The enormous enhancement of the capture cross section is just due to the large overlap of the incident neutron wave with the extended tail of the halo. The 10Be(n,γ)11Be capture reaction is involved in the inhomogeneous big-bang nucleosynthesis. We have evaluated its reaction rates at stellar energies with the nuclear ANC method.
The role of Carbon Capture and Storage in a future sustainable energy system
Lund, Henrik; Mathiesen, Brian Vad
2012-01-01
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...
2012-02-14
...The proposed information collection requirement described below has been submitted to the Office of Management and Budget (OMB) for review, as required by the Paperwork Reduction Act. The Department is soliciting public comments on the subject proposal. HUD is creating the Capture Energy Efficiency Measures for PIH (CEEMP) data system to track the amount and types of Energy Conservation......
Energy and material balance of CO2 capture from ambient air.
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.
Double-electron capture by highly-ionized atoms isolated at very low energy
Fogwell Hoogerheide, Shannon; Dreiling, Joan M.; Sahiner, Arda; Tan, Joseph N.
2016-05-01
Charge exchange with background gases, also known as electron capture processes, is important in the study of comets, controlled fusion energy, anti-matter atoms, and proposed one-electron ions in Rydberg states. However, there are few experiments in the very low energy regime that could be useful for further theoretical development. At NIST, highly-charged ions extracted from an electron-beam ion trap can be isolated with energy state. Analysis using a system of rate equations yields information about the ion cloud expansion and single-electron capture rates. A substantial amount of double-electron capture is also observed. We present the relative rates and discuss the error budget. SFH and JMD were funded by National Research Council Research Associateship Awards during some of this work.
Pelarigo, Jailton Gregório; Machado, Leandro; Fernandes, Ricardo Jorge; Greco, Camila Coelho; Vilas-Boas, João Paulo
2017-01-01
The purpose of this study was to examine the oxygen uptake ([Formula: see text]) kinetics and the energy systems' contribution at 97.5, 100 and 102.5% of the maximal lactate steady state (MLSS) swimming intensity. Ten elite female swimmers performed three-to-five 30 min submaximal constant swimming bouts at imposed paces for the determination of the swimming velocity (v) at 100%MLSS based on a 7 x 200 m intermittent incremental protocol until voluntary exhaustion to find the v associated at the individual anaerobic threshold. [Formula: see text] kinetics (cardiodynamic, primary and slow component phases) and the aerobic and anaerobic energy contributions were assessed during the continuous exercises, which the former was studied for the beginning and second phase of exercise. Subjects showed similar time delay (TD) (mean = 11.5-14.3 s) and time constant (τp) (mean = 13.8-16.3 s) as a function of v, but reduced amplitude of the primary component for 97.5% (35.7 ± 7.3 mL.kg.min-1) compared to 100 and 102.5%MLSS (41.0 ± 7.0 and 41.3 ± 5.4 mL.kg.min-1, respectively), and τp decreased (mean = 9.6-10.8 s) during the second phase of exercise. Despite the slow component did not occur for all swimmers at all swim intensities, when observed it tended to increase as a function of v. Moreover, the total energy contribution was almost exclusively aerobic (98-99%) at 97.5, 100 and 102.5%MLSS. We suggest that well-trained endurance swimmers with a fast TD and τp values may be able to adjust faster the physiological requirements to minimize the amplitude of the slow component appearance, parameter associated with the fatigue delay and increase in exhaustion time during performance, however, these fast adjustments were not able to control the progressive fatigue occurred slightly above MLSS, and most of swimmers reached exhaustion before 30min swam.
Machado, Leandro; Fernandes, Ricardo Jorge; Greco, Camila Coelho
2017-01-01
The purpose of this study was to examine the oxygen uptake (V˙O2) kinetics and the energy systems’ contribution at 97.5, 100 and 102.5% of the maximal lactate steady state (MLSS) swimming intensity. Ten elite female swimmers performed three-to-five 30 min submaximal constant swimming bouts at imposed paces for the determination of the swimming velocity (v) at 100%MLSS based on a 7 x 200 m intermittent incremental protocol until voluntary exhaustion to find the v associated at the individual anaerobic threshold. V˙O2 kinetics (cardiodynamic, primary and slow component phases) and the aerobic and anaerobic energy contributions were assessed during the continuous exercises, which the former was studied for the beginning and second phase of exercise. Subjects showed similar time delay (TD) (mean = 11.5–14.3 s) and time constant (τp) (mean = 13.8–16.3 s) as a function of v, but reduced amplitude of the primary component for 97.5% (35.7 ± 7.3 mL.kg.min-1) compared to 100 and 102.5%MLSS (41.0 ± 7.0 and 41.3 ± 5.4 mL.kg.min-1, respectively), and τp decreased (mean = 9.6–10.8 s) during the second phase of exercise. Despite the slow component did not occur for all swimmers at all swim intensities, when observed it tended to increase as a function of v. Moreover, the total energy contribution was almost exclusively aerobic (98–99%) at 97.5, 100 and 102.5%MLSS. We suggest that well-trained endurance swimmers with a fast TD and τp values may be able to adjust faster the physiological requirements to minimize the amplitude of the slow component appearance, parameter associated with the fatigue delay and increase in exhaustion time during performance, however, these fast adjustments were not able to control the progressive fatigue occurred slightly above MLSS, and most of swimmers reached exhaustion before 30min swam. PMID:28245246
Scaling and low energy constants in lattice QCD with N_f=2 maximally twisted Wilson quarks
Dimopoulos, P; Herdoiza, G; Urbach, C; Wenger, U
2007-01-01
We report on the scaling of basic hadronic observables in lattice QCD with N_f=2 maximally twisted Wilson dynamical quarks. We give preliminary results for some of the Gasser-Leutwyler low energy constants, the chiral condensate and the average mass of u and d quarks.
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.
Direct capture of low-energy neutrons by {sup 16}O
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)
Accelerating progress toward operational excellence of fossil energy plants with CO2 capture
Zitney, S.; Liese, E.; Mahapatra, P.; Turton, R. Bhattacharyya, D.
2012-01-01
To address challenges in attaining operational excellence for clean energy plants, the National Energy Technology Laboratory has launched a world-class facility for Advanced Virtual Energy Simulation Training And Research (AVESTARTM). The AVESTAR Center brings together state-of-the-art, real-time, high-fidelity dynamic simulators with operator training systems and 3D virtual immersive training systems into an integrated energy plant and control room environment. This paper will highlight the AVESTAR Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of an integrated gasification combined cycle power plant (IGCC) with carbon dioxide capture.
Diego-Ayala, U.; Martinez-Gonzalez, P.; McGlashan, N; Pullen, K. R.
2008-01-01
Capturing braking energy by regeneration into an onboard energy storage unit offers the potential to reduce significantly the fuel consumption of vehicles. A common technique is to generate electricity in the motors of a hybrid electric vehicle when braking, and to use this to charge an onboard electrochemical battery. However, such batteries are costly, bulky, and generally not amenable to fast charging as this affects battery life and capacity. In order to overcome these problems, a mechani...
Analytical sensitivities and energies of thermal-neutron-capture gamma rays
Duffey, D.; El-Kady, A.; Senftle, F.E.
1970-01-01
A table of the analytical sensitivities of the principal lines in the thermal-neutron-capture gamma ray spectrum has been compiled for most of the elements. In addition a second table of the full-energy, single-escape, and double-escape peaks has been compiled according to energy for all significant lines above 3 MeV. Lines that contrast well with adjacent lines are noted as prominent. The tables are useful for spectral interpretation and calibration. ?? 1970.
Analytical sensitivities and energies of thermal neutron capture gamma rays II
Senftle, F.E.; Moore, H.D.; Leep, D.B.; El-Kady, A.; Duffey, D.
1971-01-01
A table of the analytical sensitivities of the principal lines in the thermal neutron capture gamma-ray spectrum from 0 to 3 MeV has been compiled for most of the elements. A tabulation of the full-energy, single-escape, and double-escape peaks has also been made according to energy. The tables are useful for spectral interpretation and calibration. ?? 1971.
Beam neutron energy optimization for boron neutron capture therapy using Monte Carlo method
Ali Pazirandeh; Elham Shekarian
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 gliobelastoma multiform (GBM) requires beam of neutrons of higher energy that can penetrate deeply into the brain and thermalize in the proximity of the tumor. Dosage...
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.
Energy Capture from Thermolytic Solutions in Microbial Reverse-Electrodialysis Cells
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%.
Tsai, Tein-Shun; Lee, How-Jing; Tu, Ming-Chung
2009-11-01
With bioenergetic modeling, we tested the hypothesis that reptiles maximize net energy gain by postprandial thermal selection. Previous studies have shown that Chinese green tree vipers (Trimeresurus s. stejnegeri) have postprandial thermophily (mean preferred temperature T(p) for males =27.8 degrees C) in a linear thigmothermal gradient when seclusion sites and water existed. With some published empirical models of digestion associated factors for this snake, we calculated the average rate (E(net)) and efficiency (K(net)) of net energy gain from possible combinations of meal size, activity level, and feeding frequency at each temperature. The simulations consistently revealed that E(net) maximizes at the T(p) of these snakes. Although the K(net) peaks at a lower temperature than E(net), the value of K(net) remains high (>=0.85 in ratio to maximum) at the peak temperature of E(net). This suggested that the demands of both E(net) and K(net) can be attained by postprandial thermal selection in this snake. In conclusion, the data support our prediction that postprandial thermal selection may maximize net energy gain.
Neutrino energy loss by electron capture in magnetic field at the crusts of neutron stars
LIU Jing-Jing; LUO Zhi-Quan
2008-01-01
Based on the p-f shell model,the effect of strong magnetic field on neutrino energy loss rates by electron capture is investigated.The calculations show that the magnetic field has only a slight effect on the neutrino energy loss rates in the range of 108-1013 G on the surfaces of most neutron stars.But for some magnetars,the range of the magnetic field is 1013-1018 G,and the neutrino energy loss rates are greatly reduced,even by more than four orders of magnitude due to the strong magnetic field.
Fuzzy neural network output maximization control for sensorless wind energy conversion system
Lin, Whei-Min; Hong, Chih-Ming [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung (China); Cheng, Fu-Sheng [Department of Electrical Engineering, Cheng-Shiu University, Kaohsiung (China)
2010-02-15
This paper presents the design of an online training fuzzy neural network (FNN) controller with a high-performance speed observer for the induction generator (IG). The proposed output maximization control is achieved without mechanical sensors such as the wind speed or position sensor, and the new control system will deliver maximum electric power with light weight, high efficiency, and high reliability. The estimation of the rotor speed is designed on the basis of the sliding mode control theory. (author)
Nils Johnson; Joan Ogden
2010-12-31
In this final report, we describe research results from Phase 2 of a technical/economic study of fossil hydrogen energy systems with carbon dioxide (CO{sub 2}) capture and storage (CCS). CO{sub 2} capture and storage, or alternatively, CO{sub 2} capture and sequestration, involves capturing CO{sub 2} from large point sources and then injecting it into deep underground reservoirs for long-term storage. By preventing CO{sub 2} emissions into the atmosphere, this technology has significant potential to reduce greenhouse gas (GHG) emissions from fossil-based facilities in the power and industrial sectors. Furthermore, the application of CCS to power plants and hydrogen production facilities can reduce CO{sub 2} emissions associated with electric vehicles (EVs) and hydrogen fuel cell vehicles (HFCVs) and, thus, can also improve GHG emissions in the transportation sector. This research specifically examines strategies for transitioning to large-scale coal-derived energy systems with CCS for both hydrogen fuel production and electricity generation. A particular emphasis is on the development of spatially-explicit modeling tools for examining how these energy systems might develop in real geographic regions. We employ an integrated modeling approach that addresses all infrastructure components involved in the transition to these energy systems. The overall objective is to better understand the system design issues and economics associated with the widespread deployment of hydrogen and CCS infrastructure in real regions. Specific objectives of this research are to: Develop improved techno-economic models for all components required for the deployment of both hydrogen and CCS infrastructure, Develop novel modeling methods that combine detailed spatial data with optimization tools to explore spatially-explicit transition strategies, Conduct regional case studies to explore how these energy systems might develop in different regions of the United States, and Examine how the
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
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.
Collision energy dependence of He and Ne capture by C sup + sub 60
Campbell, E.E.B.; Ehlich, R.; Hielscher, A.; Frazao, J.M.A.; Hertel, I.V. (Freiburg Univ. (Germany). Fakultaet fuer Physik Freiburg Univ. (Germany). Freiburger Materialforschungszentrum (FMF))
1992-04-01
Recently, reports of the formation of endohedral cluster compounds He{alpha}C{sup +}{sub n} and Ne{alpha}C{sup +}{sub n-4} (n even and {<=}60) have been published for high energy collisions between C{sup +}{sub 60} and rare gases. Here we present the collision energy dependence for the formation of He{alpha}C{sup +}{sub 60} and Ne{alpha}C{sup +}{sub 60} in the region of the energetic threshold for the capture process. The threshold for He capture lies at 6{+-}2 eV in the centre of mass reference frame whereas that for Ne lies somewhat higher at 9{+-}1 eV. ({alpha} means endohedral fulleren compounds.) (orig.).
Ulmer, W
2011-01-01
The conventional treatment of the Bethe-Bloch equation for protons accounts for electron capture at the end of the projectile track by the small Barkas correction. This is only a possible way for protons, whereas for light and heavier charged nuclei the exchange of energy and charge along the track has to be accounted for by regarding the projectile charge q as a function of the residual energy. This leads to a significant modification of the Bethe-Bloch equation, otherwise the range in a medium is incorrectly determined. The LET in the Bragg peak domain and distal end is significantly influenced by the electron capture. A rather significant result is that in the domain of the Bragg peak the superiority of carbon ions is reduced compared to protons.
Spin observables in deuteron-proton radiative capture at intermediate energies
Mehmandoost-Khajeh-Dad, A A; Bacelar, J C S; Van den Berg, A M; Castelijns, R; Deltuva, A; Van Garderen, E; Glöckle, W; Golak, J; Kalantar-Nayestanaki, N; Kamada, H; Koohi-Fayegh-Dehkordi, R; L"ohner, H; Mahjour-Shafiei, M; Mardanpur, H; Messchendorp, J G; Nogga, A; Sauer, P; Shende, S V; Skibinski, R; Witala, H; W"ortche, H J
2005-01-01
A radiative deuteron-proton capture experiment was carried out at KVI using polarized-deuteron beams at incident energies of 55, 66.5, and 90 MeV/nucleon. Vector and tensor-analyzing powers were obtained for a large angular range. The results are interpreted with the help of Faddeev calculations, which are based on modern two- and three-nucleon potentials. Our data are described well by the calculations, and disagree significantly with the observed tensor anomaly at RCNP.
Electron capture collisions involving low-energy highly-stripped projectiles
Cocke, C.L.; Gray, T.J.; Justiniano, E.; Can, C.; Waggoner, B.; Varghese, S.L.; Mann, R. (Kansas State Univ., Manhattan (USA). Dept. of Physics)
1983-01-01
Recoil ions produced by fast-ion bombardment of dilute gases are in use at Kansas State University as a source of low-energy highly-charged ions to study electron capture by these projectiles on neutral targets in the 10/sup 6/-10/sup 7/ cm s/sup -1/ velocity range. A progress report on several phases of this program is summarized.
Variable-speed wind power system with improved energy capture via multilevel conversion
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.
Microbial Electrolytic Carbon Capture for Carbon Negative and Energy Positive Wastewater Treatment.
Lu, Lu; Huang, Zhe; Rau, Greg H; Ren, Zhiyong Jason
2015-07-07
Energy and carbon neutral wastewater management is a major goal for environmental sustainability, but current progress has only reduced emission rather than using wastewater for active CO2 capture and utilization. We present here a new microbial electrolytic carbon capture (MECC) approach to potentially transform wastewater treatment to a carbon negative and energy positive process. Wastewater was used as an electrolyte for microbially assisted electrolytic production of H2 and OH(-) at the cathode and protons at the anode. The acidity dissolved silicate and liberated metal ions that balanced OH(-), producing metal hydroxide, which transformed CO2 in situ into (bi)carbonate. Results using both artificial and industrial wastewater show 80-93% of the CO2 was recovered from both CO2 derived from organic oxidation and additional CO2 injected into the headspace, making the process carbon-negative. High rates and yields of H2 were produced with 91-95% recovery efficiency, resulting in a net energy gain of 57-62 kJ/mol-CO2 captured. The pH remained stable without buffer addition and no toxic chlorine-containing compounds were detected. The produced (bi)carbonate alkalinity is valuable for wastewater treatment and long-term carbon storage in the ocean. Preliminary evaluation shows promising economic and environmental benefits for different industries.
Proton capture cross section of 7Be and the flux of high energy solar neutrinos
Filippone, B.W.; Elwyn, A. J.; Davids, C. N.; Koetke, D.D.
1983-01-01
The low energy cross section for the 7Be(p, γ)8B reaction has been measured by detecting the delayed α particles from the 8B beta decay. Detailed discussion is presented of the analysis of the radioactive 7Be target including the use of two independent methods to determine the 7Be areal density. The direct capture part of the cross section is subtracted from the total cross section to deduce resonance parameters for the 1+ first excited state in 8B. The zero-energy astrophysical S factor infe...
Low energy behavior of astrophysical S factor in radiative captures to loosely bound final states
Mukhamedzhanov, A M
2002-01-01
The low-energy behavior of the astrophysical S-factor for E1 direct radiative captures a(p,gamma)b leading to loosely bound final states (b=a+p) is investigated. We derive a first-order integral representation for S(E) and focus on the properties around zero energy. We show that it is the competition between various effects, namely the remnant Coulomb barrier, the initial and final centrifugal barriers and the binding energy, that defines the behavior of the S(E->0). Contrary to previous findings, we prove that S(E->0) is not determined by the pole corresponding to the bound state. The derivative S'(0) increases with the increase of the centrifugal barrier, while it decreases with the charge of the target. For l_i=l_f+1 the increase of the binding energy of the final nucleus increases the derivative S'(0) while for l_i=l_f-1 the opposite effect is found. We make use of our findings to explain the low energy behavior of the S-factors related to some notorious capture reactions: 7Be(p, gamma)8B, 14N(p,gamma)15O...
Noris, Federico [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Vermeer, Kimberly [Urban Habitat Initiatives Inc., Boston, MA (United States); Adamkiewicz, Gary [Harvard School of Public Health, Boston, MA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2013-06-01
The current focus on building energy retrofit provides an opportunity to simultaneously improve indoor environmental quality (IEQ). Toward this end, we developed a protocol for selecting packages of retrofits that both save energy and improve IEQ in apartments. The protocol specifies the methodology for selecting retrofits from a candidate list while addressing expected energy savings, IEQ impacts, and costs in an integrated manner. Interviews, inspections and measurements are specified to collect the needed input information. The protocol was applied to 17 apartments in three buildings in two different climates within California. Diagnostic measurements and surveys conducted before and after retrofit implementation indicate enhanced apartment performance.
Feasibility of low energy radiative capture experiments at the LUNA underground accelerator facility
Bemmerer, D; Lemut, A; Bonetti, R; Broggini, C; Corvisiero, P; Costantini, H; Cruz, J; Formicola, A; Fülöp, Z; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, G; Imbriani, G; Jesus, A P; Junker, M; Limata, B; Menegazzo, R; Prati, P; Roca, V; Rogalla, D; Rolfs, C; Romano, M; Alvarez, C R; Schumann, F; Somorjai, E; Straniero, O; Strieder, F; Terrasi, F; Trautvetter, H P; Vomiero, A; Fulop, Zs.; Gyurky, Gy.
2005-01-01
The LUNA (Laboratory Underground for Nuclear Astrophysics) facility has been designed to study nuclear reactions of astrophysical interest. It is located deep underground in the Gran Sasso National Laboratory, Italy. Two electrostatic accelerators, with 50 and 400 kV maximum voltage, in combination with solid and gas target setups allowed to measure the total cross sections of the radiative capture reactions $^2$H(p,$\\gamma$)3He and $^{14}$N(p,$\\gamma$)$^{15}$O within their relevant Gamow peaks. We report on the gamma background in the Gran Sasso laboratory measured by germanium and bismuth germanate detectors, with and without an incident proton beam. A method to localize the sources of beam induced background using the Doppler shift of emitted gamma rays is presented. The feasibility of radiative capture studies at energies of astrophysical interest is discussed for several experimental scenarios.
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.
Hopewell Beneficial CO2 Capture for Production of Fuels, Fertilizer and Energy
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
Self-suspended vibration-driven energy harvesting chip for power density maximization
Murillo, Gonzalo; Agustí, Jordi; Abadal, Gabriel
2015-11-01
This work introduces a new concept to integrate energy-harvesting devices with the aim of improving their throughput, mainly in terms of scavenged energy density and frequency tunability. This concept, named energy harvester in package (EHiP), is focused on the heterogeneous integration of a MEMS die, dedicated to scavenging energy, with an auxiliary chip, which can include the control and power management circuitry, sensors and RF transmission capabilities. The main advantages are that the whole die can be used as an inertial mass and the chip area usage is optimized. Based on this concept, in this paper we describe the development and characterization of a MEMS die fully dedicated to harvesting mechanical energy from ambient vibrations through an electrostatic transduction. A test PCB has been fabricated to perform the assembly that allows measurement of the resonance motion of the whole system at 289 Hz. An estimated maximum generated power of around 11 μW has been obtained for an input vibration acceleration of ˜10 m s-2 when the energy harvester operates in a constant-charge cycle for the best-case scenario. Therefore, a maximum scavenged power density of 0.85 mW cm-3 is theoretically expected for the assembled system. These results demonstrate that the generated power density of any vibration-based energy harvester can be significantly increased by applying the EHiP concept, which could become an industrial standard for manufacturing this kind of system, independently of the transduction type, fabrication technology or application.
Vessally, Esmail; Aryana, Soma
2016-01-01
The purpose of this research is to study the solar energy storage in norbornadiene ( 1)/quadricyclane ( 2) system by four direct attachments of substituents at two carbon atoms on both sides of the double bonds C2=C3 and C5=C6 in 1 X and 2 X; calculating the relative energies at B3LYP/6-311++G** level of theory. The solar energy storage of four electron donating substituents, (push-push effect), X (X =-NH2,-OH) and four electron withdrawing substituents, (pull-pull effect) X (X =-CO2H,-CONH2,-NO2 and CN) were examined. The solar absorption bands were calculated for 1 X. The DFT calculations reveal that the bands were shifted to the visible spectrum region when the electron withdrawing substituents were used rather than the electron donating substituents.
Mohammed, K; Ahammad, S Z; Sallis, P J; Mota, C R
2014-01-01
Algal based wastewater treatment (WWT) technologies are attracting renewed attention because they couple energy-efficient sustainable treatment with carbon capture, and reduce the carbon footprint of the process. A low-cost energy-efficient mixed microalgal culture-based pilot WWT system, coupled with carbon dioxide (CO2) sequestration, was investigated. The 21 L stirred-tank photobioreactors (STPBR) used light-emitting diodes as the light source, resulting in substantially reduced operational costs. The STPBR were operated at average optimal light intensity of 582.7 μmol.s(-1).m(-2), treating synthetic municipal wastewater containing approximately 250, 90 and 10 mg.L(-1) of soluble chemical oxygen demand (SCOD), ammonium (NH4-N), and phosphate, respectively. The STPBR were maintained for 64 days without oxygen supplementation, but had a supply of CO2 (25 mL.min(-1), 25% v/v in N2). Relatively high SCOD removal efficiency (>70%) was achieved in all STPBR. Low operational cost was achieved by eliminating the need for mechanical aeration, with microalgal photosynthesis providing all oxygenation. The STPBR achieved an energy saving of up to 95%, compared to the conventional AS system. This study demonstrates that microalgal photobioreactors can provide effective WWT and carbon capture, simultaneously, in a system with potential for scaling-up to municipal WWT plants.
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.
Rahnama, Nader; Gaeini, Abbas Ali; Kazemi, Fahimeh
2010-05-01
Consumption of energy drinks has become widespread among athletes. The effectiveness of Red Bull and Hype energy drinks on selected indices of maximal cardiorespiratory fitness and blood lactate levels in male athletes was examined in this study. TEN MALE STUDENT ATHLETES (AGE: 22.4 ± 2.1 years, height: 180.8 ± 7.7 cm, weight: 74.2 ± 8.5 kg) performed three randomized maximal oxygen consumption tests on a treadmill. Each test was separated by four days and participants were asked to ingest Red Bull, Hype or placebo drinks 40 minutes before the exercise bout. The VO (2max), time to exhaustion, heart rate and lactate were measured to determine if the caffeine-based beverages influence performance. ANOVA test was used for analyzing data. A greater value was observed in VO (2max)and time to exhaustion for the Red Bull and Hype trial compared to the placebo trial (p drinks (p > 0.05). For blood lactate levels no significant changes were observed before and two minute after the test (p > 0.05). Ingestion of Red Bull and Hype prior to exercise testing is effective on some indices of cardiorespiratory fitness but not on the blood lactate levels.
Nader Rahnama
2010-01-01
Full Text Available Background: Consumption of energy drinks has become widespread among athletes. The effectiveness of Red Bull and Hype energy drinks on selected indices of maximal cardiorespiratory fitness and blood lactate levels in male athletes was examined in this study. Methods: Ten male student athletes (age: 22.4 ± 2.1 years, height: 180.8 ± 7.7 cm, weight: 74.2 ± 8.5 kg performed three randomized maximal oxygen consumption tests on a treadmill. Each test was separated by four days and participants were asked to ingest Red Bull, Hype or placebo drinks 40 minutes before the exercise bout. The VO 2max , time to exhaustion, heart rate and lactate were measured to determine if the caffeine-based beverages influence performance. ANOVA test was used for analyzing data. Results: A greater value was observed in VO 2max and time to exhaustion for the Red Bull and Hype trial compared to the placebo trial (p 0.05. For blood lactate levels no significant changes were observed before and two minute after the test (p > 0.05. Conclusions: Ingestion of Red Bull and Hype prior to exercise testing is effective on some indices of cardiorespira-tory fitness but not on the blood lactate levels.
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.
Post combustion CO2 capture as energy penalty in real power plant by retrofiting exergy efficiency
Parvandad Asadollahi, Maryam [Department of Mechanics, University of Manchester (United Kingdom)], e-mail: maryamassadollahi@yahoo.com
2011-07-01
Carbon dioxide (CO2) capture and storage is the only way the world to continue to enjoy the benefits of using coal while drastically reducing the emissions associated with coal combustion. CO2 is a component of the flue gas in a coal-fired power plant. The total pressure of the flue gas is 1 atm and the CO2 concentration is typically 10-15%. The process of transforming this low pressure, low concentration CO2 into a relatively pure CO2 stream is referred to as post-combustion capture. Present-day post-combustion capture plants currently use chemical absorption processes. Three systems based on amine-, carbonate- and ammonia-based process are discussed and presented in this paper. Use of other solvents with lower binding energy is suggested to decrease the exergy loss at the reboiler section. By adding flash for desalinating saline water, exergy loss is reduced significantly and extraction of steam at various pressures is possible through the heat recovery steam generator.
Nabi, Jameel-Un; 10.1103/PhysRevC.77.055802
2011-01-01
Proton-neutron quasi-particle random phase approximation (pn-QRPA) theory has recently being used for calculation of stellar weak interaction rates of $fp$-shell nuclide with success. Neutrino losses from proto-neutron stars play a pivotal role to decide if these stars would be crushed into black holes or explode as supernovae. The product of abundance and positron capture rates on $^{55}$Co is substantial and as such can play a role in fine tuning of input parameters of simulation codes specially in the presupernova evolution. Recently we introduced our calculation of capture rates on $^{55}$Co, in a luxurious model space of $7 \\hbar \\omega$, employing the pn-QRPA theory with a separable interaction. Simulators, however, may require these rates on a fine scale. Here we present for the first time an expanded calculation of the neutrino energy loss rates and positron capture rates on $^{55}$Co on an extensive temperature-density scale. These type of scale is appropriate for interpolation purposes and of greate...
Impact of kiln thermal energy demand and false air on cement kiln flue gas CO2 capture
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.
Beam neutron energy optimization for boron neutron capture therapy using Monte Carlo method
Ali Pazirandeh
2006-06-01
Full Text Available 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 gliobelastoma multiform (GBM requires beam of neutrons of higher energy that can penetrate deeply into the brain and thermalize 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 optimal neutron energy for deep seated tumors depends on the size 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
Gao, Z J; Merlitz, H; Pagni, P J; Chen, Z
2014-01-01
Transient processes generally constitute part of energy-system cycles. If skillfully manipulated, they actually are capable of assisting systems to behave beneficially to suit designers' needs. In the present study, behaviors related to both thermal conductivities ($\\kappa$) and heat capacities ($c_{v}$) are analyzed. Along with solutions of the temperature and the flow velocity obtained by means of theories and simulations, three findings are reported herein: $(1)$ effective $\\kappa$ and effective $c_{v}$ can be controlled to vary from their intrinsic material-property values to a few orders of magnitude larger; $(2)$ a parameter, tentatively named as "nonlinear thermal bias", is identified and can be used as a criterion in estimating energies transferred into the system during heating processes and effective operating ranges of system temperatures; $(3)$ When a body of water, such as the immense ocean, is subject to the boundary condition of cold bottom and hot top, it may be feasible to manipulate transien...
The use of social media to maximize energy performance in the United States Marine Corps
Reed, Matthew B.; McIntyre, Donald M.; Gatchalian, Nomer I.
2014-01-01
Approved for public release; distribution is unlimited This research identified social media strategies that could be useful for influencing energy consumption behavior in the United States Marine Corps. We reviewed literature on social learning and media choice that allowed us to develop a media fit/social learning interaction framework for analysis purposes. Using this framework, we conducted a comparative case analysis of eight social media campaigns that varied on factors such as organ...
Kimizuka, Nobuo; Yanai, Nobuhiro; Morikawa, Masa-Aki
2016-11-29
The self-assembly of functional molecules into ordered molecular assemblies and the fulfillment of potentials unique to their nanotomesoscopic structures have been one of the central challenges in chemistry. This Feature Article provides an overview of recent progress in the field of molecular self-assembly with the focus on the triplet-triplet annihilation-based photon upconversion (TTA-UC) and supramolecular storage of photon energy. On the basis of the integration of molecular self-assembly and photon energy harvesting, triplet energy migration-based TTA-UC has been achieved in varied molecular systems. Interestingly, some molecular self-assemblies dispersed in solution or organogels revealed oxygen barrier properties, which allowed TTA-UC even under aerated conditions. The elements of molecular self-assembly were also introduced to the field of molecular solar thermal fuel, where reversible photoliquefaction of ionic crystals to ionic liquids was found to double the molecular storage capacity with the simultaneous pursuit of switching ionic conductivity. A future prospect in terms of innovating molecular self-assembly toward molecular systems chemistry is also discussed.
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)
Kuramochi, T.|info:eu-repo/dai/nl/304838683; Ramirez, C.A.|info:eu-repo/dai/nl/284852414; Turkenburg, W.C.|info:eu-repo/dai/nl/073416355; Faaij, A.P.C.|info:eu-repo/dai/nl/10685903X
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
Tan, Qing [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Yu, Sha [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Evans, Meredydd [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mathur, Jyotirmay [Malaviya National Institute of Technology, Jaipur (India); Vu, Linh D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2016-05-01
India adopted the Energy Conservation Building Code (ECBC) in 2007. Rajasthan is the first state to make ECBC mandatory at the state level. In collaboration with Malaviya National Institute of Technology (MNIT) Jaipur, Pacific Northwest National Laboratory (PNNL) has been working with Rajasthan to facilitate the implementation of ECBC. This report summarizes milestones made in Rajasthan and PNNL's contribution in institutional set-ups, capacity building, compliance enforcement and pilot building construction.
Capturing Inter-Annual Variability of PV Energy Production in South Asia
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.
Comparison of energy cost of maximal strength and local muscle endurance training in young women
Márcio Antonio Gonsalves Sindorf
2013-04-01
Full Text Available The aim of this study was to compare the energy cost (EC of two weight training protocols in young women. Twelve women between 18 and 29 years old participated in the study. All the volunteers were under one maximum repetition test (1RM, protocols of maximum strength training (MS, and local muscle endurance training (LME. At rest, during of the training session and 30 minutes of recovery, the measures of the expired air were made through metabolic gases analyzer and module of telemetry. There were not significant differences (p > .05 in EC at rest before MS session and LME session, the EC in kcal/min was higher (p < .01 during LME than MS, and the total EC of MS was higher (p > .05 than LME session. The energy expenditure returned to resting values before 30 minutes in both sessions. It was concluded that the MS and LME weight training sessions resulted in a low EC.
Liu, Gang; Bao, Jie
2017-08-21
Energy consumption and wastewater generation in cellulosic ethanol production are among the determinant factors on overall cost and technology penetration into fuel ethanol industry. This study analyzed the energy consumption and wastewater generation by the new biorefining process technology, dry acid pretreatment and biodetoxification (DryPB), as well as by the current mainstream technologies. DryPB minimizes the steam consumption to 8.63GJ and wastewater generation to 7.71tons in the core steps of biorefining process for production of one metric ton of ethanol, close to 7.83GJ and 8.33tons in corn ethanol production, respectively. The relatively higher electricity consumption is compensated by large electricity surplus from lignin residue combustion. The minimum ethanol selling price (MESP) by DryPB is below $2/gal and falls into the range of corn ethanol production cost. The work indicates that the technical and economical gap between cellulosic ethanol and corn ethanol has been almost filled up. Copyright © 2017 Elsevier Ltd. All rights reserved.
Low Mass Printable Devices for Energy Capture, Storage, and Use for Space Exploration Missions
Frazier, Donald O.; Singer, Christopher E.; 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 -Technologies Worldwide, Inc., and the National Aeronautics and Space Administration s (NASA s) Marshall Space Flight Center (MSFC). This work combines semiconductor and printing technologies to advance lightweight electronic and photonic devices having excellent potential for commercial and exploration applications, and is an example of industry and government cooperation that leads to novel inventions. Device development involves three energy generation and consumption projects: 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 supercapacitors. 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 will be useful for lightweight power generation that enables inner planetary missions using smaller launch vehicles and facilitates surface operations. 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. All three components may be printed in line by printing sequential layers on a standard screen or flexographic direct impact press using the threedimensional printing technique (3DFM) patented by NthDegree. MSFC is testing the robustness of prototype devices in the harsh space and lunar surface environments, and available results will be reported. Unlike many traditional light sources, this device does not contain toxic compounds, and the LED component has passed stringent off-gassing tests required for potential manifesting on spacecraft such as the International Space
Neutrino energy loss by electron capture on strongly screened iron group nuclei
Liu Jing-Jing; Luo Zhi-Quan
2007-01-01
The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that at a temperature of 15 × 109 K, the neutrino energy loss rates which come from the electron capture processfor most iron group nuclei decrease no more than 2 orders of magnitude but for the others (such as 53,55,56,57,58,59,60Co, 56,59Ni) they can decrease about 3 orders of magnitude due to strong electron screening (SES), whereas, at a temperature of 109K the neutrino energy loss rates of the most iron group nuclei can be diminished greatly due to the SES. For example, 61Fe, 60Fe,and 62Ni the neutrino energy loss rates decrease about 4, 15 and 16 orders of magnitude and for 57Cr, 58Cr, and 60Cr decrease about 18, 12, and 10 orders of magnitude respectively. According to our calculations the neutrino energy loss rates of nuclei 58Mn, 59Mn, 60Mn, and 62Mn may decrease about 13 orders of magnitude at a temperature of 109 K due to the SES.
Advanced Low Energy Enzyme Catalyzed Solvent for CO{sub 2} Capture
Zaks, Alex; Reardon, John
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 Nm{sup 3}/hr (dry basis); and ~ 80% CO{sub 2} capture was demonstrated at ~ 30 Nm{sup 3}/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 CO{sub 2} for this solvent, which was below the target of <2.1 GJ/t CO{sub 2}. 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 CO{sub 2} including all CO{sub 2} 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 CO{sub 2} by ~10% below reference NETL Case-12. Based on these results, a directional plan was identified to reduce the cost of CO{sub 2} capture in future work.
Trade-offs between energy maximization and parental care in a central place forager, the sea otter
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.
Skylarks trade size and energy content in weed seeds to maximize total ingested lipid biomass.
Gaba, Sabrina; Collas, Claire; Powolny, Thibaut; Bretagnolle, François; Bretagnolle, Vincent
2014-10-01
The trade-off between forage quality and quantity has been particularly studied in herbivore organisms, but much less for seed eating animals, in particular seed-eating birds which constitute the bulk of wintering passerines in European farmlands. The skylark is one of the commonest farmland birds in winter, mainly feeding on seeds. We focus on weed seeds for conservation and management purposes. Weed seeds form the bulk of the diet of skylarks during winter period, and although this is still a matter for discussion, weed seed predation by granivorous has been suggested as an alternative to herbicides used to regulate weed populations in arable crops. Our objectives were to identify whether weed seed traits govern foraging decisions of skylarks, and to characterize key seed traits with respect to size, which is related to searching and handling time, and lipid content, which is essential for migratory birds. We combined a single-offer experiment and a multiple-offer one to test for feeding preferences of the birds by estimating seed intake on weed seed species differing in their seed size and seed lipid content. Our results showed (1) a selective preference for smaller seeds above a threshold of seed size or seed size difference in the pair and, (2) a significant effect of seed lipid biomass suggesting a trade-off between foraging for smaller seeds and selecting seeds rich in lipids. Skylarks foraging decision thus seems to be mainly based on seed size, that is presumably a 'proxy' for weed seed energy content. However, there are clearly many possible combinations of morphological and physiological traits that must play crucial role in the plant-bird interaction such as toxic compound or seed coat. Copyright © 2014 Elsevier B.V. All rights reserved.
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.
Resonant antineutrino induced electron capture with low energy bound-beta beams
Oldeman, R G C; Saitta, B
2009-01-01
Antineutrino induced electron capture is a resonant process that can have a larg e cross-section for beams of monochromatic antineutrinos. We calculate the cross-section of this process and investigate an experimental setup where monochromatic antineutrinos are produced from the bound-beta decay of fully ionized radioactive atoms in a storage ring. If the energy between the source and the target is well matched, the cross-sections can be significantly larger than the cross-sections of commonly used non-resonant processes. The rate that can be achieved at a small distance between the source and two targets of $10^3$ kg is up to one interaction per $8 .3\\cdot10^{18}$ decaying atoms. For a source-target distance corresponding to the first atmospheric neutrino osc illation maximum, the largest rate is one interaction per $3.2\\cdot10^{21}$ decaying atoms.
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
Advanced virtual energy simulation training and research: IGCC with CO2 capture power plant
Zitney, S.; Liese, E.; Mahapatra, P.; Bhattacharyya, D.; Provost, G.
2011-01-01
In this presentation, we highlight the deployment of a real-time dynamic simulator of an integrated gasification combined cycle (IGCC) power plant with CO{sub 2} capture at the Department of Energy's (DOE) National Energy Technology Laboratory's (NETL) Advanced Virtual Energy Simulation Training and Research (AVESTARTM) Center. The Center was established as part of the DOE's accelerating initiative to advance new clean coal technology for power generation. IGCC systems are an attractive technology option, generating low-cost electricity by converting coal and/or other fuels into a clean synthesis gas mixture in a process that is efficient and environmentally superior to conventional power plants. The IGCC dynamic simulator builds on, and reaches beyond, conventional power plant simulators to merge, for the first time, a 'gasification with CO{sub 2} capture' process simulator with a 'combined-cycle' power simulator. Fueled with coal, petroleum coke, and/or biomass, the gasification island of the simulated IGCC plant consists of two oxygen-blown, downward-fired, entrained-flow, slagging gasifiers with radiant syngas coolers and two-stage sour shift reactors, followed by a dual-stage acid gas removal process for CO{sub 2} capture. The combined cycle island consists of two F-class gas turbines, steam turbine, and a heat recovery steam generator with three-pressure levels. The dynamic simulator can be used for normal base-load operation, as well as plant start-up and shut down. The real-time dynamic simulator also responds satisfactorily to process disturbances, feedstock blending and switchovers, fluctuations in ambient conditions, and power demand load shedding. In addition, the full-scope simulator handles a wide range of abnormal situations, including equipment malfunctions and failures, together with changes initiated through actions from plant field operators. By providing a comprehensive IGCC operator training system, the
Brendle, Joerg
2016-01-01
We show that, consistently, there can be maximal subtrees of P (omega) and P (omega) / fin of arbitrary regular uncountable size below the size of the continuum. We also show that there are no maximal subtrees of P (omega) / fin with countable levels. Our results answer several questions of Campero, Cancino, Hrusak, and Miranda.
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
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 post-combust
Kim, Hyuk Joon; Lee, Seul-Yi; Sinh, Le Hoang; Yeo, Chang Su; Son, Yeong Rae; Cho, Kang Rae; Song, YoonKyu; Ju, Sanghyun; Shin, Min Kyoon; Park, Soo-Jin; Park, SangYoon
2017-04-01
Graphene has attracted widespread attention for supercapacitor applications thank to their excellent conductivity, mechanical flexibility, chemical stability and extremely high specific surface area. Here, all-graphene-oxide-supercapacitors were developed from two reduced graphene oxide (rGO) films as electrodes and one graphene oxide (GO) film as separator. The supercapacitors were then treated with 4M sulfuric acid at temperatures around 80 °C. By this treatment, the sulfuric acid molecules were physically intercalated into both rGO and GO films, which were confirmed by significant decrease intensity of characteristic peaks of sulfuric acid in Raman spectra. These sulfuric-acid-intercalated GO films can function as both quasi-solid-state electrolytes and separators. The average capacitance values measured at 100 mV s-1 of the thermally wetted supercapacitor at 84 °C is improved 93.7 times higher than that of the as-prepared all-graphene-oxide-supercapacitor. The maximum capacitance of 266 F cm-3 is obtained at scan rate 10 mV s-1 for the thermally wetted supercapacitor at 84 °C. To the best of our knowledge, this is the highest specific capacitance that has ever been reported for a graphene oxide-based supercapacitor. Importantly, being in a quasi-solid-state, the energy storage performance of supercapacitors are persistent over several thousand cycles, making it very much unlike other carbon-based supercapacitors.
Self-supporting power plant. Capturing evaporated water and save energy a new source of water
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.
Van Wagener D.H.
2014-11-01
Full Text Available Absorption/stripping using alkanolamine solvents for removing CO2 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 reboiler. 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°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°C. The results indicate that the overall process is feasible and that costs are of similar magnitude to standard designs.
McCall, Shakira Renee
In an effort to stress the benefits of the application of renewable energy to the next generation of science, technology, engineering, arts, and mathematics (STEAM) professionals, instructional modules on energy and biogas were integrated into a summer camp curriculum that challenged students to apply STEAM concepts in the design and development of chain reaction machines. Each module comprised an interactive presentations and a hands-on component where students operated a manipulative relevant to the content. During summer 2013, this camp was implemented at two high schools in Arizona and one in Trinidad and Tobago. Assessments showed that the overall modules were effective in helping students learn and retain the information presented on energy and biogas production. To improve future implementations of these modules, specifically the module on biogas production, the anaerobic digester was redesigned. In addition, a designed experiment was conducted to determine how to optimize the influent and operational environment that is available in an average high school classroom to generate maximum biogas yield. Eight plug-flow anaerobic digesters made of PVC piping and fixtures were used in a 2x3 factorial design assessing: co-digestion (20mL or 50mL) used cooking oil, temperature (25°C or 40°C), and addition of inoculum (0mL or 200mL). Biogas production was captured at two intervals over a 30-day period, and the experiments were replicated three times. Results showed that temperature at 40°C significantly increased biogas production and should be used over 25°C when using anaerobic digesters. Other factors that may potentially increase biogas production are combination of temperature at 40°C and 50mL of used cooking oil. In the future, the improvements made in the design of the anaerobic digester, and the applications of the finding from the experimental design, are expected to lead to an improved manipulative for teaching students about biogas production.
Goldberg, David S; Lackner, Klaus S; Han, Patrick; Slagle, Angela L; Wang, Tao
2013-07-02
Reducing atmospheric CO2 using a combination of air capture and offshore geological storage can address technical and policy concerns with climate mitigation. Because CO2 mixes rapidly in the atmosphere, air capture could operate anywhere and in principle reduce CO2 to preindustrial levels. We investigate the Kerguelen plateau in the Indian Ocean, which offers steady wind resources, vast subseafloor storage capacities, and minimal risk of economic damages or human inconvenience and harm. The efficiency of humidity swing driven air capture under humid and windy conditions is tested in the laboratory. Powered by wind, we estimate ∼75 Mt CO2/yr could be collected using air capture and sequestered below seafloor or partially used for synfuel. Our analysis suggests that Kerguelen offers a remote and environmentally secure location for CO2 sequestration using renewable energy. Regional reservoirs could hold over 1500 Gt CO2, sequestering a large fraction of 21st century emissions.
Du, Guanyao; Yu, Jianjun
2016-01-01
This paper investigates the system achievable rate for the multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system with an energy harvesting (EH) relay. Firstly we propose two protocols, time switching-based decode-and-forward relaying (TSDFR) and a flexible power splitting-based DF relaying (PSDFR) protocol by considering two practical receiver architectures, to enable the simultaneous information processing and energy harvesting at the relay. In PSDFR protocol, we introduce a temporal parameter to describe the time division pattern between the two phases which makes the protocol more flexible and general. In order to explore the system performance limit, we discuss the system achievable rate theoretically and formulate two optimization problems for the proposed protocols to maximize the system achievable rate. Since the problems are non-convex and difficult to solve, we first analyze them theoretically and get some explicit results, then design an augmented Lagrangian penalty function (ALPF) based algorithm for them. Numerical results are provided to validate the accuracy of our analytical results and the effectiveness of the proposed ALPF algorithm. It is shown that, PSDFR outperforms TSDFR to achieve higher achievable rate in such a MIMO-OFDM relaying system. Besides, we also investigate the impacts of the relay location, the number of antennas and the number of subcarriers on the system performance. Specifically, it is shown that, the relay position greatly affects the system performance of both protocols, and relatively worse achievable rate is achieved when the relay is placed in the middle of the source and the destination. This is different from the MIMO-OFDM DF relaying system without EH. Moreover, the optimal factor which indicates the time division pattern between the two phases in the PSDFR protocol is always above 0.8, which means that, the common division of the total transmission time into two equal phases in
Co-location of air capture, sub-ocean CO2 storage and energy production on the Kerguelen plateau
Goldberg, D.; Han, P.; Lackner, K.; Wang, T.
2011-12-01
How can carbon capture and storage activities be sustained from an energy perspective while keeping the entire activity out of sight and away from material risk and social refrain near populated areas? In light of reducing the atmospheric CO2 level to mitigate its effect on climate change, the combination of new air-capture technologies and large offshore storage reservoirs, supplemented by carbon neutral renewable energy, could address both of these engineering and public policy concerns. Because CO2 mixes rapidly in the atmosphere, air capture scrubbers could be located anywhere in the world. Although the power requirements for this technology may reduce net efficiencies, the local availability of carbon-neutral renewable energy for this purpose would eliminate some net energy loss. Certain locations where wind speeds are high and steady, such as those observed at high latitude and across the open ocean, appeal as carbon-neutral energy sources in close proximity to immense and secure reservoirs for geological sequestration of captured CO2. In particular, sub-ocean basalt flows are vast and carry minimal risks of leakage and damages compared to on-land sites. Such implementation of a localized renewable energy source coupled with carbon capture and storage infrastructure could result in a global impact of lowered CO2 levels. We consider an extreme location on the Kerguelen plateau in the southern Indian Ocean, where high wind speeds and basalt storage reservoirs are both plentiful. Though endowed with these advantages, this mid-ocean location incurs clear material and economic challenges due to its remoteness and technological challenges for CO2 capture due to constant high humidity. We study the wind energy-air capture power balance and consider related factors in the feasibility of this location for carbon capture and storage. Other remote oceanic sites where steady winds blow and near large geological reservoirs may be viable as well, although all would require
Kim, Huiyong; Hwang, Sung June; Lee, Kwang Soon
2015-02-03
Among various CO2 capture processes, the aqueous amine-based absorption process is considered the most promising for near-term deployment. However, the performance evaluation of newly developed solvents still requires complex and time-consuming procedures, such as pilot plant tests or the development of a rigorous simulator. Absence of accurate and simple calculation methods for the energy performance at an early stage of process development has lengthened and increased expense of the development of economically feasible CO2 capture processes. In this paper, a novel but simple method to reliably calculate the regeneration energy in a standard amine-based carbon capture process is proposed. Careful examination of stripper behaviors and exploitation of energy balance equations around the stripper allowed for calculation of the regeneration energy using only vapor-liquid equilibrium and caloric data. Reliability of the proposed method was confirmed by comparing to rigorous simulations for two well-known solvents, monoethanolamine (MEA) and piperazine (PZ). The proposed method can predict the regeneration energy at various operating conditions with greater simplicity, greater speed, and higher accuracy than those proposed in previous studies. This enables faster and more precise screening of various solvents and faster optimization of process variables and can eventually accelerate the development of economically deployable CO2 capture processes.
Impact of kiln thermal energy demand and false air on cement kiln flue gas CO2 capture
Udara S. P. R. Arachchige, Dinesh Kawan, Lars-André Tokheim, Morten C. Melaaen
2014-01-01
Full Text Available 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.
ZHOU Chun-Mei; WU Zhen-Dong; HUANG Xiao-Long
2005-01-01
Calculations of energies and absolute intensities of Auger electron and X-ray arising from electron capture are introduced briefly. The calculation codes and main process are also presented. The application is also given by taking 55Fe ε decay as an example.
Koelbl, B.S.
2016-01-01
This thesis investigates the deployment potential of Carbon Capture and Storage (CCS) under stringent climate policy targets and the possible macro-economic implications. First, we look at the use of CCS in scenarios of different Energy-Economy and Integrated Assessment Models. These scenarios look
Rivard, Mark Joseph
Examination of neutron dosimetry for 252Cf has been conducted using calculative and experimental means. Monte Carlo N-Particle (MCNP) transport code was used in a distributed computing environment as a parallel virtual machine (PVM) to determine the absorbed neutron dose and neutron energy spectrum from 252Cf in a variety of clinically relevant materials. Herein, a Maxwellian spectrum was used to model the 252Cf neutron emissions within these materials. 252Cf mixed-field dosimetry of Applicator Tube (AT) type sources was measured using 1.0 and 0.05 cm3 tissue-equivalent ion chambers and a miniature GM counter. A dosimetry protocol was formulated similar that of ICRU 45. The 252Cf AT neutron dosimetry was determined in the cylindrical coordinate system formalism recommended by the AAPM Task Group 43. These results demonstrated the overwhelming dependence of dosimetry on the source geometry factor as there was no significant neutron attenuation within the source or encapsulation. Gold foils and TLDs were used to measure the thermal flux in the vicinity of 252Cf AT sources to compare with the results calculated using MCNP. As the fast neutron energy spectrum did not markedly changed at increasing distances from the AT source, neutron dosimetry results obtained with paired ion chambers using fixed sensitivity factors agreed well with MCNP results and those in the literature. Calculations of moderated 252Cf neutron energy spectrum with various loadings of 10B and 157Gd were performed, in addition to analysis of neutron capture therapy dosimetry with these isotopes. Radiological concerns such as personnel exposure and shielding of 252Cf emissions were examined. Feasibility of a high specific-activity 252Cf HDR source was investigated through radiochemical and metallurgical studies using stand-ins such as Tb, Gd and 249Cf. Issues such as capsule burst strength due to helium production for a variety of proposed HDR sources were addressed. A recommended 252Cf source
K B Athreya
2009-09-01
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 $\\int fh_id_=_i$ for $i=1,2,\\ldots,\\ldots k$ the maximizer of entropy is an $f_0$ that is proportional to $\\exp(\\sum c_i h_i)$ for some choice of $c_i$. An extension of this to a continuum of constraints and many examples are presented.
Gao Hongtao
2015-09-01
Full Text Available Floating-type wave energy converter has the advantages of high wave energy conversion efficiency, strong shock resistance ability in rough sea and stable output power. So it is regarded as a promising energy utilization facility. The research on hydrodynamic performance of wave capture buoys is the precondition and key to the wave energy device design and optimization. A simplified motion model of the buoys in the waves is established. Based on linear wave theory, the equations of motion of buoys are derived according to Newton’s second law. The factors of wave and buoys structural parameters on wave energy absorption efficiency are discussed in the China’s Bohai Sea with short wave period and small wave height. The results show that the main factor which affects the dynamic responses of wave capture buoys is the proximity of the natural frequency of buoys to the wave period. And the incoming wave power takes a backseat role to it at constant wave height. The buoys structural parameters such as length, radius and immersed depth, influence the wave energy absorption efficiency, which play significant factors in device design. The effectiveness of this model is validated by the sea tests with small-sized wave energy devices. The establishment methods of motion model and analysis results are expected to be helpful for designing and manufacturing of floating-type wave energy converter.
Liu, Jing-Jing
2016-01-01
Based on the relativistic mean-field effective interactions theory, and Lai dong model \\citep{b37, b38, b39}, we discuss the influences of superstrong magnetic fields (SMFs) on electron Fermi energy, nuclear blinding energy, and single-particle level structure in magnetars surface. By using the method of Shell-Model Monte Carlo (SMMC), and the Random Phase Approximation (RPA) theory, we detailed analyze the neutrino energy loss rates(NELRs) by electron capture (EC) for iron group nuclei in SMFs.
Voiantis, Stefanos; Secher, Niels H.; Quistorff, Bjørn
2010-01-01
Maximal exercise elicits systemic acidosis where venous pH can drop to 6.74 and here we assessed how much lower the intracellular value (pHi) might be. The wrist flexor muscles are intensively involved in rowing and 31P-magnetic resonance spectroscopy allows for calculation of forearm pHi and ene......Maximal exercise elicits systemic acidosis where venous pH can drop to 6.74 and here we assessed how much lower the intracellular value (pHi) might be. The wrist flexor muscles are intensively involved in rowing and 31P-magnetic resonance spectroscopy allows for calculation of forearm p...
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.)
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.
Bochon, Krzysztof; Chmielniak, Tadeusz
2015-03-01
In the study an accurate energy and economic analysis of the carbon capture installation was carried out. Chemical absorption with the use of monoethanolamine (MEA) and ammonia was adopted as the technology of carbon dioxide (CO2) capture from flue gases. The energy analysis was performed using a commercial software package to analyze the chemical processes. In the case of MEA, the demand for regeneration heat was about 3.5 MJ/kg of CO2, whereas for ammonia it totalled 2 MJ/kg CO2. The economic analysis was based on the net present value (NPV) method. The limit price for CO2 emissions allowances at which the investment project becomes profitable (NPV = 0) was more than 160 PLN/Mg for MEA and less than 150 PLN/Mg for ammonia. A sensitivity analysis was also carried out to determine the limit price of CO2 emissions allowances depending on electricity generation costs at different values of investment expenditures.
Application of modern smokeless biomass pyrolysis for biochar and biofuel production is potentially a revolutionary approach for global carbon capture and sequestration at gigatons of carbon (GtC) scales. A conversion of about 7% of the annual terrestrial gross photosynthetic product (120 GtC y-1) i...
Molina, F; Aguilera, P; Romero-Barrientos, J; Arellano, H F; Agramunt, J; Medel, J; Morales, J R; Zambra, M
2017-08-04
We present a methodology to obtain the energy distribution of the neutron flux of an experimental nuclear reactor, using multi-foil activation measurements and the Expectation Maximization unfolding algorithm, which is presented as an alternative to well known unfolding methods such as GRAVEL. Self-shielding flux corrections for energy bin groups were obtained using MCNP6 Monte Carlo simulations. We have made studies at the at the Dry Tube of RECH-1 obtaining fluxes of 1.5(4)×10(13)cm(-2)s(-1) for the thermal neutron energy region, 1.9(5)×10(12)cm(-2)s(-1) for the epithermal neutron energy region, and 4.3(11)×10(11)cm(-2)s(-1) for the fast neutron energy region. Copyright © 2017 Elsevier Ltd. All rights reserved.
Design of low-energy neutron beams for boron neutron capture synovectomy
Yanch, Jacquelyn C.; Shefer, Ruth E.; Binello, E.
1997-02-01
A novel application of the 10B(n, (alpha) )7Li nuclear reaction for the treatment of rheumatoid arthritis is under development. this application, called Boron Neutron Capture Synovectomy (BNCS), is briefly described here and the differences between BNCS and Boron Neutron Capture Therapy (BNCT) are discussed in detail. These differences lead to substantially altered demands on neutron beam design for each therapy application. In this paper the considerations for neutron beam design for the treatment of arthritic joints via BNCS are discussed, and comparisons with the design requirements for BNCT are made. This is followed by a description of potential moderator/reflector assemblies that are calculated to produce intense, high- quality neutron beams based on the 7Li(p,n) accelerator- based reactions. Total therapy time and therapeutic ratios are given as a function of both moderator length and boron concentration. Finally, a means of carrying out multi- directional irradiations of arthritic joints is proposed.
Capture cross sections of 15N(n, {\\gamma})16N at astrophysical energies
Fan, Guang-wei; Sheng, Zong-qiang; Tian, Feng; Wang, Jun; Zhang, Chao
2016-01-01
We have reanalyzed reaction cross sections of 16N on 12C target. The nucleon density distribution of 16N, especially surface density distribution, was extracted using the modified Glauber model. On the basis of dilute surface densities, the discussion of 15N(n, {\\gamma})16N reaction was performed within the framework of the direct capture reaction mechanism. The calculations agreed quite well with the experimental data.
Social group utility maximization
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
Thomas E. Sather
2016-06-01
Conclusions: A lower age of first energy drink use suggests higher risk of single-occasion heavy episodic consumption in this military population. Researchers should further explore the relationship of early onset energy drink consumption and potential future health risks.
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.
An Agent-Based Infrastructure for Energy Profile Capture and Management
Padget, J.; Riat, H.; Warnier, M.E.; Brazier, F.M.T.; Natarajan, S.
2010-01-01
Accurately and dynamically monitoring energy usage patterns in households forms a first requirement for more efficient and ecofriendly energy management in the future. Monitored energy usage data can be used by power systems engineering—to inform demand-side management systems in the near future ter
Li, Sheng; Jin, Hongguang; Gao, Lin; Mumford, Kathryn Anne; Smith, Kathryn; Stevens, Geoff
2014-12-16
Energy and exergy analyses were studied for an integrated gasification combined cycle (IGCC) power plant with CO2 capture using hot potassium carbonate solvent. The study focused on the combined impact of the CO conversion ratio in the water gas shift (WGS) unit and CO2 recovery rate on component exergy destruction, plant efficiency, and energy penalty for CO2 capture. A theoretical limit for the minimal efficiency penalty for CO2 capture was also provided. It was found that total plant exergy destruction increased almost linearly with CO2 recovery rate and CO conversion ratio at low CO conversion ratios, but the exergy destruction from the WGS unit and the whole plant increased sharply when the CO conversion ratio was higher than 98.5% at the design WGS conditions, leading to a significant decrease in plant efficiency and increase in efficiency penalty for CO2 capture. When carbon capture rate was over around 70%, via a combination of around 100% CO2 recovery rate and lower CO conversion ratios, the efficiency penalty for CO2 capture was reduced. The minimal efficiency penalty for CO2 capture was estimated to be around 5.0 percentage points at design conditions in an IGCC plant with 90% carbon capture. Unlike the traditional aim of 100% CO conversion, it was recommended that extremely high CO conversion ratios should not be considered in order to decrease the energy penalty for CO2 capture and increase plant efficiency.
Capture cross sections of 15N(n, γ)16N at astrophysical energies
Fan, Guang-Wei; Ma, Jun-Bing; Sheng, Zong-Qiang; Shi, Guo-Zhu; Tian, Feng; Wang, Jun; Zhang, Chao
2016-12-01
We have reanalyzed reaction cross sections of 16N on a 12C target. The nucleon density distribution of 16N, especially surface density distribution, was extracted using the modified Glauber model. On the basis of dilute surface densities, the 15N(n, γ)16N reaction is discussed within the framework of the direct capture reaction mechanism. The calculations agree quite well with the experimental data. Support given by National Natural Science Foundation of China (11447236, 11505002, 11247001) and Foundation of Anhui University of Science and Technology (11130, 12608)
Kölle, V; Braitmayer, S E; Mohr, P J; Wilmes, S; Staudt, G; Hammer, J W; Jäger, M; Knee, H; Kunz, R; Mayer, A
1999-01-01
Several resonances of the capture reaction sup 2 sup 0 Ne(alpha, gamma) sup 2 sup 4 Mg were measured using an extended windowless gas target system. Detailed GEANT simulations were performed to derive the strength and the total width of the resonances from the measured yield curve. The crucial experimental parameters, which are mainly the density profile in the gas target and the efficiency of the gamma-ray detector, were analyzed by a comparison between the measured data and the corresponding simulation calculations. The excellent agreement between the experimental data and the simulations gives detailed insight into these parameters. (author)
D. I. Komar
2016-01-01
Full Text Available Medical, and technological linear particle accelerators, and nuclear reactors are vastly widespread worldwide today. These facility generate fields of secondary gamma radiation with energy to 10 MeV. Therefore, we have a need to calibrate spectrometric and dosimetric ionization measurement instruments for the energies to 10 MeV. The aim of this work is to determine possibility to use thermal neutron collimator of АТ140 Neutron Calibration Facility with 238Pu-Be fast neutron source (IBN-8-6 for this. Below 3 MeV we use a set of point gamma standard spectrometry sources OSGI. We can acquire gamma rays with energies above 3 MeV using radioactive thermal neutron capture on target, i.e. (n, γ-nuclear reaction. We can use neutron capture gamma-ray from titanium target (to 7 MeV or nickel target (to 10 MeV situated in thermal neutron field for calibration. We can use thermal neutron collimator of АТ140 Neutron Calibration Facility with 238Pu-Be fast neutron source (IBN-8-6 for slowing down neutrons from radionuclide fast neutron sources to thermal energies in polyethylene. Thermal neutron collimator forms a beam from radionuclide source with a significant amount of neutrons with thermal energies. We placed Ti and Ni targets in collimator’s canal. We got experimental spectral data on detection unit BDKG-19M NaI(Tl 63 × 160 mm with nonlinear channel-energy conversion characteristic in range to 10 MeV. For additional filtration we proposed to use polyethylene neutron reflector and lead discs. We experimentally determined that placement of lead discs in collimator in front of the target allows to filter all spectrum while insignificantly weakening target’s emission. Using theoretical and experimental data we proved the ability to calibrate gamma-ray spectrometers in the range to 10 MeV.
Carbon capture and storage as central modules of a strategy toward a sustainable energy supply
Schiffer, Hans-Wilhelm
2010-09-15
Sustainable energy supply must do justice to the equal-ranking goals of economic, environmental and social compatibility. A balance must be sought between the degrees of achievement for these aims. In climate protection, approaches must be pursued that promise achievement at the lowest cost. An approximation of energy-management development to climate-policy necessities is only possible if all cost-efficient options are used. CCS can be regarded as a bridging technology toward an energy sector that is increasingly based almost entirely on electricity from renewables. On the road there, the expansion of renewables and power generation based on fossil energies with CCS complement one another.
Zhang, C J; Hua, J F; Xu, X L; Li, F; Pai, C-H; Wan, Y; Wu, Y P; Gu, Y Q; Mori, W B; Joshi, C; Lu, W
2016-07-11
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.
Zhang, C. J.; Hua, J. F.; Xu, X. L.; Li, F.; Pai, C.-H.; Wan, Y.; Wu, Y. P.; Gu, Y. Q.; Mori, W. B.; Joshi, C.; Lu, W.
2016-07-01
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.
Bolinger, Mark
2014-04-09
This report compares the relative costs, benefits, and implications of capturing the value of renewable energy tax benefits in these three different ways – applying them against outside income , carrying them forward in time until they can be fully absorbed internally, or monetizing them through third-party tax equity investors – to see which method is most competitive under various scenarios. It finds that under current law and late-2013 market conditions, monetization makes sense for all but the most tax-efficient project sponsors. In other words, for most project sponsors, bringing in third-party tax equity currently provides net benefits to a project.
Cabrera-Trujillo, R. [Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611-8435 (United States); Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, Cuernavaca, Morelos, 62251 (Mexico); Sabin, John R. [Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611-8435 (United States)]. E-mail: sabin@qtp.ufl.edu; Deumens, Erik [Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611-8435 (United States); Ohrn, Yngve [Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611-8435 (United States)
2007-08-15
The subject of the work presented here is related to damage caused by energetic, charged particle radiation such as electrons, protons, and alpha particles to prebiotic matter such as that found in interstellar space. The calculations are carried out using an all electron, all nuclei, scheme that explicitly treats the electron-nuclear coupling. We present results for the no-capture, as well as the single and double electron capture probabilities, as well as for the 1s and 2l (l = s, p) contributions to the electron capture cross-sections of {sup 3}He{sup 2+} projectiles on formaldehyde molecules. We find that the summed cross-section peaks at 10 keV/amu, and has a plateau between 0.1 and 1 keV/amu. We also present preliminary results for the nuclear, ro-vibrational and electronic stopping cross-section. We find a large contribution to the electronic stopping cross-section and a maximum shifted towards higher energies in the nuclear stopping cross-section, when compared to SRIM results. We interpret this to be a consequence of molecular bonding.
Pazirandeh, Ali; Azizi, Maryam; Farhad Masoudi, S
2006-01-01
Among many conventional techniques, nuclear techniques have shown to be faster, more reliable, and more effective in detecting explosives. In the present work, neutrons from a 5 Ci Am-Be neutron source being in water tank are captured by elements of soil and landmine (TNT), namely (14)N, H, C, and O. The prompt capture gamma-ray spectrum taken by a NaI (Tl) scintillation detector indicates the characteristic photo peaks of the elements in soil and landmine. In the high-energy region of the gamma-ray spectrum, besides 10.829 MeV of (15)N, single escape (SE) and double escape (DE) peaks are unmistakable photo peaks, which make the detection of concealed explosive possible. The soil has the property of moderating neutrons as well as diffusing the thermal neutron flux. Among many elements in soil, silicon is more abundant and (29)Si emits 10.607 MeV prompt capture gamma-ray, which makes 10.829 MeV detection difficult. The Monte Carlo simulation was used to adjust source-target-detector distances and soil moisture content to yield the best result. Therefore, we applied MCNP4C for configuration very close to reality of a hidden landmine in soil.
Matsuo, Tomoaki; Ohkawara, Kazunori; Seino, Satoshi; Shimojo, Nobutake; Yamada, Shin; Ohshima, Hiroshi; Tanaka, Kiyoji; Mukai, Chiaki
2013-02-01
Maximal oxygen consumption decreases during spaceflight, and astronauts also experience controversial weight loss. Future space missions require a more efficient exercise program to maintain work efficiency and to control increased energy expenditure (EE). We have been developing two types of original exercise training protocols which are better suited to astronauts’ daily routine exercise during long-term spaceflight: sprint interval training (SIT) and high-intensity interval aerobic training (HIAT). In this study, we compared the total EE, including excess post-exercise energy expenditure (EPEE), induced by our interval cycling protocols with the total EE of a traditional, continuous aerobic training (CAT). In the results, while the EPEEs after the SIT and HIAT were greater than after the CAT, the total EE for an entire exercise/rest session with the CAT was the greatest of our three exercise protocols. The SIT and HIAT would be potential protocols to control energy expenditure for long space missions.
Gebraad, Pieter [National Renewable Energy Laboratory, Golden CO USA; Thomas, Jared J. [Brigham Young University, Provo UT USA; Ning, Andrew [Brigham Young University, Provo UT USA; Fleming, Paul [National Renewable Energy Laboratory, Golden CO USA; Dykes, Katherine [National Renewable Energy Laboratory, Golden CO USA
2016-05-24
This paper presents a wind plant modeling and optimization tool that enables the maximization of wind plant annual energy production (AEP) using yaw-based wake steering control and layout changes. The tool is an extension of a wake engineering model describing the steady-state effects of yaw on wake velocity profiles and power productions of wind turbines in a wind plant. To make predictions of a wind plant's AEP, necessary extensions of the original wake model include coupling it with a detailed rotor model and a control policy for turbine blade pitch and rotor speed. This enables the prediction of power production with wake effects throughout a range of wind speeds. We use the tool to perform an example optimization study on a wind plant based on the Princess Amalia Wind Park. In this case study, combined optimization of layout and wake steering control increases AEP by 5%. The power gains from wake steering control are highest for region 1.5 inflow wind speeds, and they continue to be present to some extent for the above-rated inflow wind speeds. The results show that layout optimization and wake steering are complementary because significant AEP improvements can be achieved with wake steering in a wind plant layout that is already optimized to reduce wake losses.
Characterization of Qatar's surface carbonates for CO2 capture and thermochemical energy storage
Kakosimos, Konstantinos E.; Al-Haddad, Ghadeer; Sakellariou, Kyriaki G.; Pagkoura, Chrysa; Konstandopoulos, Athanasios G.
2017-06-01
Samples of surface carbonates were collected from three different areas of the Qatar peninsula. We employed material characterization techniques to examine the morphology and composition of the samples, while their CO2 capture capacity was assessed via multiple successive calcination-carbonation cycles. Our samples were mainly calcite and dolomite based. Calcite samples showed higher initial capacity of around 11 mmol CO2 g-1 which decayed rapidly to less than 2 mmol CO2 g-1. On the other hand, dolomite samples showed an excellent stability (˜15 cycles) with a capacity of 6 mmol CO2 g-1. The performance of the dolomite samples is better compared to other similar natural samples, from literature. A promising result for future studies towards improving their performance by physical and chemical modification.
Agnihotri, Neha
2016-11-01
Five potential push-pull porphyrin dyes (PR1-PR5) substituted with extended rylene anhydride units (n = 1-5) as electron acceptors and (4-dimethylamino) phenyl ethynylene as an electron donor have been investigated computationally using density functional theory and time dependent-density functional theory. Their molecular orbital energies are reported together with their singlet and triplet electronic transition energies, oscillator strengths and charge transfer characteristics. These sensitizers are panchromatic, their fully-allowed charge transfer transitions extend well into the near infrared and their HOMO and LUMO energies appear well-matched to the band gap and electrochemical potential requirements of dye-sensitized solar cells (DSSCs).
COD capture: a feasible option towards energy self-sufficient domestic wastewater treatment
Wan, Junfeng; Gu, Jun; Zhao, Qian; Liu, Yu
2016-04-01
Although the activated sludge process, one of the most remarkable engineering inventions in the 20th century, has made significant contribution to wastewater reclamation in the past 100 years, its high energy consumption is posing a serious impact and challenge on the current wastewater industry worldwide and is also inevitably linked to the issue of global climate change. In this study, we argued that substantial improvement in the energy efficiency might be no longer achievable through further optimization of the activated sludge process. Instead, we should devote more effort to the development or the adoption of novel treatment configurations and emerging technologies. Of which an example is A-B process which can significantly improve the energy recovery potential at A-stage, while markedly reduces energy consumption at B-stage. Various configurations of A-B process with energy analysis are thus discussed. It appears highly possible to achieve an overall energy gain in WWTPs with A-B process as a core.
Sutter, Daniel; Gazzani, Matteo; Mazzotti, Marco
2016-10-20
A new ammonia-based process for CO2 capture from flue gas has been developed, which utilizes the formation of solid ammonium bicarbonate to increase the CO2 concentration in the regeneration section of the process. Precipitation, separation, and dissolution of the solid phase are realized in a dedicated process section, while the packed absorption and desorption columns remain free of solids. Additionally, the CO2 wash section applies solid formation to enable a reduction of the wash water consumption. A rigorous performance assessment employing the SPECCA index (Specific Primary Energy Consumption for CO2 Avoided) has been implemented to allow for a comparison of the overall energy penalty between the new process and a standard ammonia-based capture process without solid formation. A thorough understanding of the relevant solid-solid-liquid-vapor phase equilibria and an accurate modeling of them have enabled the synthesis of the process, and have inspired the development of the optimization algorithm used to screen a wide range of operating conditions in equilibrium-based process simulations. Under the assumptions on which the analysis is based, the new process with controlled solid formation achieved a SPECCA of 2.43 MJ kgCO2(-1), corresponding to a reduction of 17% compared to the process without solid formation (with a SPECCA of 2.93 MJ kgCO2(-1)). Ways forward to confirm this significant improvement, and to increase the accuracy of the optimization are also discussed.
Japaridze, George
2015-01-01
I discuss an upper bound on the boost and the energy of elementary particles. The limit is derived utilizing the core principle of relativistic quantum mechanics stating that there is a lower limit for localization of an elementary quantum system and the suggestion that when the localization scale reaches the Planck length, elementary particles are removed from observables. The limit for the boost and energy, $M_{Planck}/m$ and $M_{Planck}c^{2}\\approx\\,8.6* 10^{27}$ eV, is defined in terms of fundamental constants and the mass of elementary particle and does not involve any dynamic scale. These bounds imply that the cosmic ray flux of any flavor may stretch up to energies of order $10^{18}$ GeV and will cut off at this value.
Zhang, C J; Xu, X L; Li, F; Pai, C -H; Wan, Y; Wu, Y P; Gu, Y Q; Mori, W B; Joshi, C; Lu, W
2016-01-01
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime...
Capturing RNA Folding Free Energy with Coarse-Grained Molecular Dynamics Simulations
Bell, David R.; Cheng, Sara Y.; Salazar, Heber; Ren, Pengyu
2017-01-01
We introduce a coarse-grained RNA model for molecular dynamics simulations, RACER (RnA CoarsE-gRained). RACER achieves accurate native structure prediction for a number of RNAs (average RMSD of 2.93 Å) and the sequence-specific variation of free energy is in excellent agreement with experimentally measured stabilities (R2 = 0.93). Using RACER, we identified hydrogen-bonding (or base pairing), base stacking, and electrostatic interactions as essential driving forces for RNA folding. Also, we found that separating pairing vs. stacking interactions allowed RACER to distinguish folded vs. unfolded states. In RACER, base pairing and stacking interactions each provide an approximate stability of 3–4 kcal/mol for an A-form helix. RACER was developed based on PDB structural statistics and experimental thermodynamic data. In contrast with previous work, RACER implements a novel effective vdW potential energy function, which led us to re-parameterize hydrogen bond and electrostatic potential energy functions. Further, RACER is validated and optimized using a simulated annealing protocol to generate potential energy vs. RMSD landscapes. Finally, RACER is tested using extensive equilibrium pulling simulations (0.86 ms total) on eleven RNA sequences (hairpins and duplexes). PMID:28393861
Joan M. Ogden
2005-11-29
In this final progress report, we describe research results from Phase I of a technical/economic study of fossil hydrogen energy systems with CO{sub 2} sequestration. This work was performed under NETL Award No. DE-FC26-02NT41623, during the period September 2002 through August 2005 The primary objective of the study is to better understand system design issues and economics for a large-scale fossil energy system co-producing H{sub 2} and electricity with CO{sub 2} sequestration. This is accomplished by developing analytic and simulation methods for studying the entire system in an integrated way. We examine the relationships among the different parts of a hydrogen energy system, and identify which variables are the most important in determining both the disposal cost of CO{sub 2} and the delivered cost of H{sub 2}. A second objective is to examine possible transition strategies from today's energy system toward one based on fossil-derived H{sub 2} and electricity with CO{sub 2} sequestration. We carried out a geographically specific case study of development of a fossil H{sub 2} system with CO{sub 2} sequestration, for the Midwestern United States, where there is presently substantial coal conversion capacity in place, coal resources are plentiful and potential sequestration sites in deep saline aquifers are widespread.
Ng, Kim Choon
2017-08-31
The adsorbate-adsorbent thermodynamics are complex as it is influenced by the pore size distributions, surface heterogeneity and site energy distribution, as well as the adsorbate properties. Together, these parameters defined the adsorbate uptake forming the state diagrams, known as the adsorption isotherms, when the sorption site energy on the pore surfaces are favorable. The available adsorption models for describing the vapor uptake or isotherms, hitherto, are individually defined to correlate to a certain type of isotherm patterns. There is yet a universal approach in developing these isotherm models. In this paper, we demonstrate that the characteristics of all sorption isotherm types can be succinctly unified by a revised Langmuir model when merged with the concepts of Homotattic Patch Approximation (HPA) and the availability of multiple sets of site energy accompanied by their respective fractional probability factors. The total uptake (q/q*) at assorted pressure ratios (P/P s ) are inextricably traced to the manner the site energies are spread, either naturally or engineered by scientists, over and across the heterogeneous surfaces. An insight to the porous heterogeneous surface characteristics, in terms of adsorption site availability has been presented, describing the unique behavior of each isotherm type.
Joan M. Ogden
2003-12-01
In this second semi-annual progress report, we describe research results from an ongoing study of fossil hydrogen energy systems with CO{sub 2} sequestration. This work was performed under NETL Award No. DE-FC26-02NT41623, during the six-month period March 2003 through September 2003. The primary objective of the study is to better understand system design issues and economics for a large-scale fossil energy system co-producing H{sub 2} and electricity with CO{sub 2} sequestration. This is accomplished by developing analytic and simulation methods for studying the entire system in an integrated way. We examine the relationships among the different parts of a hydrogen energy system, and attempt to identify which variables are the most important in determining both the disposal cost of CO{sub 2} and the delivered cost of H{sub 2}. A second objective is to examine possible transition strategies from today's energy system toward one based on fossil-derived H{sub 2} and electricity with CO{sub 2} sequestration. We are carrying out a geographically specific case study of development of a fossil H{sub 2} system with CO{sub 2} sequestration, for the Midwestern United States, where there is presently substantial coal conversion capacity in place, coal resources are plentiful and potential sequestration sites in deep saline aquifers are widespread.
Meerburg, Francis A; Boon, Nico; Van Winckel, Tim; Vercamer, Jensen A R; Nopens, Ingmar; Vlaeminck, Siegfried E
2015-03-01
The conventional activated sludge process is widely used for wastewater treatment, but to progress toward energy self-sufficiency, the wastewater treatment scheme needs to radically improve energy balances. We developed a high-rate contact stabilization (HiCS) reactor system at high sludge-specific loading rates (>2 kg bCOD kg(-1)TSS d(-1)) and low sludge retention times (organics than high-rate conventional activated sludge (HiCAS) and the low-rate variants of HiCS and HiCAS. The best HiCS system recovered 36% of the influent chemical energy as methane, due to the combined effects of low production of CO2, high sludge yield, and high methane yield of the produced sludge. The HiCS system imposed a feast-famine cycle and a putative selection pressure on the sludge micro-organisms toward substrate adsorption and storage. Given further optimization, it is a promising process for energy recovery from wastewater.
Macroalgae for CO_{2} Capture and Renewable Energy - A Pilot Project
Wiley, Kristine [Gas Technology Inst., Des Plaines, IL (United States)
2011-01-31
The objective of this project was to demonstrate, at a pilot scale, the beneficial use of carbon dioxide (CO_{2}) through a technology designed to capture CO_{2} from fossil-fuel fired power plant stack gas, generating macroalgae and converting the macroalgae at high efficiency to renewable methane that can be utilized in the power plant or introduced into a natural gas pipeline. The proposed pilot plant would demonstrate the cost-effectiveness and CO_{2}/ NO_{x} flue-gas removal efficiency of an innovative algal scrubber technology where seaweeds are grown out of water on specially-designed supporting structures contained within greenhouses where the plants are constantly bathed by recycled nutrient sprays enriched by flue gas constituents. The work described in this document addresses Phase 1 of the project only. The scope of work for Phase 1 includes the completion of a preliminary design package; the collection of additional experimental data to support the preliminary and detailed design for a pilot scale utilization of CO_{2} to cultivate macroalage and to process that algae to produce methane; and a technological and economic analysis to evaluate the potential of the system. Selection criteria for macroalgae that could survive the elevated temperatures and potential periodic desiccation of near desert project sites were identified. Samples of the selected macroalgae species were obtained and then subjected to anaerobic digestion to determine conversions and potential methane yields. A Process Design Package (PDP) was assembled that included process design, process flow diagram, material balance, instrumentation, and equipment list, sizes, and cost for the Phase 2 pilot plant. Preliminary economic assessments were performed under the various assumptions made, which are purposely conservative. Based on the results, additional development work should be conducted to delineate the areas for improving efficiency, reducing
Margheritini, Lucia; Victor, L.; Kofoed, Jens Peter
2009-01-01
In multi-level wave energy converters the water from incoming waves is stored in reservoirs one on top of the other. Prevision formula for the overtopping flow rates in the individual reservoirs is fundamental for dimensioning correctly the turbines and optimizing the device. Having a number...... words, the opening between two consecutive reservoirs. 13 different geometries have been tested in 2D irregular waves and a new formulation for prediction of overtopping in multilevel structures is presented....
Exploiting stiffness nonlinearities to improve flow energy capture from the wake of a bluff body
Alhadidi, Ali H.; Abderrahmane, Hamid; Daqaq, Mohammed F.
2016-12-01
Fluid-structure coupling mechanisms such as wake galloping have been recently utilized to develop scalable flow energy harvesters. Unlike traditional rotary-type generators which are known to suffer serious scalability issues because their efficiency drops significantly as their size decreases; wake-galloping flow energy harvesters (FEHs) operate using a very simple motion mechanism, and, hence can be scaled down to fit the desired application. Nevertheless, wake-galloping FEHs have their own shortcomings. Typically, a wake-galloping FEH has a linear restoring force which results in a very narrow lock-in region. As a result, it does not perform well under the broad range of shedding frequencies normally associated with a variable flow speed. To overcome this critical problem, this article demonstrates theoretically and experimentally that, a bi-stable restoring force can be used to broaden the steady-state bandwidth of wake galloping FEHs and, thereby to decrease their sensitivity to variations in the flow speed. An experimental case study is carried out in a wind tunnel to compare the performance of a bi-stable and a linear FEH under single- and multi-frequency vortex street. An experimentally-validated lumped-parameters model of the bi-stable harvester is also introduced, and solved using the method of multiple scales to study the influence of the shape of the potential energy function on the output voltage.
Capturing the Energy Absorbing Mechanisms of Composite Structures under Crash Loading
Wade, Bonnie
As fiber reinforced composite material systems become increasingly utilized in primary aircraft and automotive structures, the need to understand their contribution to the crashworthiness of the structure is of great interest to meet safety certification requirements. The energy absorbing behavior of a composite structure, however, is not easily predicted due to the great complexity of the failure mechanisms that occur within the material. Challenges arise both in the experimental characterization and in the numerical modeling of the material/structure combination. At present, there is no standardized test method to characterize the energy absorbing capability of composite materials to aide crashworthy structural design. In addition, although many commercial finite element analysis codes exist and offer a means to simulate composite failure initiation and propagation, these models are still under development and refinement. As more metallic structures are replaced by composite structures, the need for both experimental guidelines to characterize the energy absorbing capability of a composite structure, as well as guidelines for using numerical tools to simulate composite materials in crash conditions has become a critical matter. This body of research addresses both the experimental characterization of the energy absorption mechanisms occurring in composite materials during crushing, as well as the numerical simulation of composite materials undergoing crushing. In the experimental investigation, the specific energy absorption (SEA) of a composite material system is measured using a variety of test element geometries, such as corrugated plates and tubes. Results from several crush experiments reveal that SEA is not a constant material property for laminated composites, and varies significantly with the geometry of the test specimen used. The variation of SEA measured for a single material system requires that crush test data must be generated for a range of
Capturing Thoughts, Capturing Minds?
Nielsen, Janni
2004-01-01
Think Aloud is cost effective, promises access to the user's mind and is the applied usability technique. But 'keep talking' is difficult, besides, the multimodal interface is visual not verbal. Eye-tracking seems to get around the verbalisation problem. It captures the visual focus of attention...
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.
A Demonstration System for Capturing Geothermal Energy from Mine Waters beneath Butte, Montana
Blackketter, Donald [Montana Tech of the Univ. of Montana, Butte, MT (United States)
2015-06-01
Executive Summary An innovative 50-ton ground-source heat pump (GSHP) system was installed to provide space heating and cooling for a 56,000 square foot (5,200 square meter) building in Butte Montana, in conjunction with its heating and chiller systems. Butte is a location with winter conditions much colder than the national average. The GSHP uses flooded mine waters at 78F (25C) as the heat source and heat sink. The heat transfer performance and efficiency of the system were analyzed using data from January through July 2014. This analysis indicated that for typical winter conditions in Butte, Montana, the GSHP could deliver about 88% of the building’s annual heating needs. Compared with a baseline natural-gas/electric system, the system demonstrated at least 69% site energy savings, 38% source energy savings, 39% carbon dioxide emissions reduction, and a savings of $17,000 per year (40%) in utility costs. Assuming a $10,000 per ton cost for installing a production system, the payback period at natural gas costs of $9.63/MMBtu and electricity costs of $0.08/kWh would be in the range of 40 to 50 years. At higher utility prices, or lower installation costs, the payback period would obviously be reduced.
Popcorn-Derived Porous Carbon for Energy Storage and CO2 Capture.
Liang, Ting; Chen, Chunlin; Li, Xing; Zhang, Jian
2016-08-16
Porous carbon materials have drawn tremendous attention due to its applications in energy storage, gas/water purification, catalyst support, and other important fields. However, producing high-performance carbons via a facile and efficient route is still a big challenge. Here we report the synthesis of microporous carbon materials by employing a steam-explosion method with subsequent potassium activation and carbonization of the obtained popcorn. The obtained carbon features a large specific surface area, high porosity, and doped nitrogen atoms. Using as an electrode material in supercapacitor, it displays a high specific capacitance of 245 F g(-1) at 0.5 A g(-1) and a remarkable stability of 97.8% retention after 5000 cycles at 5 A g(-1). The product also exhibits a high CO2 adsorption capacity of 4.60 mmol g(-1) under 1066 mbar and 25 °C. Both areal specific capacitance and specific CO2 uptake are directly proportional to the surface nitrogen content. This approach could thus enlighten the batch production of porous nitrogen-doped carbons for a wide range of energy and environmental applications.
Gather, Malte C; Yun, Seok Hyun
2014-12-08
Bioluminescent organisms are likely to have an evolutionary drive towards high radiance. As such, bio-optimized materials derived from them hold great promise for photonic applications. Here, we show that biologically produced fluorescent proteins retain their high brightness even at the maximum density in solid state through a special molecular structure that provides optimal balance between high protein concentration and low resonance energy transfer self-quenching. Dried films of green fluorescent protein show low fluorescence quenching (-7 dB) and support strong optical amplification (gnet=22 cm(-1); 96 dB cm(-1)). Using these properties, we demonstrate vertical cavity surface emitting micro-lasers with low threshold (lasers) and self-assembled all-protein ring lasers. Moreover, solid-state blends of different proteins support efficient Förster resonance energy transfer, with sensitivity to intermolecular distance thus allowing all-optical sensing. The design of fluorescent proteins may be exploited for bio-inspired solid-state luminescent molecules or nanoparticles.
Boron Subphthalocyanine Based Molecular Triad Systems for the Capture of Solar Energy.
Storm, Freja E; Olsen, Stine T; Hansen, Thorsten; De Vico, Luca; Jackson, Nicholas E; Ratner, Mark A; Mikkelsen, Kurt V
2016-10-06
In this study a number of chromophores based on boron subphthalocyanines are investigated for use in the future design of organic photovoltaic devices based on molecular triad systems. The computational study is performed at the TD-DFT CAM-B3LYP/6-311G(d) level of theory. The absorption spectra of these chromophores are simulated using TD-DFT and compared to experimental results. All investigated chromophores absorb light in the visible range and thus are suitable for absorption of sunlight in solar cell applications. On the basis of energy-level alignments, suitable combinations of moieties for a molecular triad system are proposed. The molecular triads will be used in future work as the functional part of organic photovoltaic devices, where the chromophore will be used both to absorb the incoming solar radiation and to increase the distance between the separated charges on donor and acceptor units to increase the lifetime of the charge-separated state.
Resource capture by single leaves
Long, S.P.
1992-05-01
Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.
WU Kai-Su; CHEN Yong-Shou; LIU Zu-Hua; LIN Cheng-Jian; ZHANG Huan-Qiao
2003-01-01
The cross section of the direct neutron capture reaction 12C(n,7)13C(l/2+) is calculated with the asymptotic normalization coefficient method. The result is in good agreement with a recent experiment at low energy. An enormous enhancement of cross section is found for this direct neutron capture in which a p-wave neutron is captured into an 2?i/2 orbit with neutron halo. The possible effect of the neutron halo structure presented in this reaction on the s-process in astrophysics is discussed in general.
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).
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%.
Nakaten, Natalie Christine
2014-11-15
Underground coal gasification (UCG) allows for exploitation of deep-seated coal seams not economically exploitable by conventional coal mining. Aim of the present study is to examine UCG economics based on coal conversion into a synthesis gas to fuel a combined cycle gas turbine power plant (CCGT) with CO2 capture and storage (CCS). Thereto, a techno-economic model is developed for UCG-CCGT-CCS costs of electricity (COE) determination which, considering sitespecific data of a selected target area in Bulgaria, sum up to 72 Euro/MWh in total. To quantify the impact of model constraints on COE, sensitivity analyses are undertaken revealing that varying geological model constraints impact COE with 0.4% to 4%, chemical with 13%, technical with 8% to 17% and market-dependent with 2% to 25%. Besides site-specific boundary conditions, UCG-CCGT-CCS economics depend on resources availability and infrastructural characteristics of the overall energy system. Assessing a model based implementation of UCG-CCGT-CCS and CCS power plants into the Bulgarian energy network revealed that both technologies provide essential and economically competitive options to achieve the EU environmental targets and a complete substitution of gas imports by UCG synthesis gas production.
Nannan eSun
2015-03-01
Full Text Available CO2 capture represents the key technology for CO2 reduction within the framework of CO2 capture, utilization, and storage (CCUS. In fact, the implementation of CO2 capture extends far beyond CCUS since it will link the CO2 emission and recycling sectors, and when renewables are used to provide necessary energy input, CO2 capture would enable a profitable zero- or even negative-emitting and integrated energy-chemical solution. To this end, highly efficient CO2 capture technologies are needed, and adsorption using solid adsorbents has the potential to be one of the ideal options. Currently, the greatest challenge in this area is the development of adsorbents with high performance that balances a range of optimization-needed factors, those including costs, efficiency, and engineering feasibility. In this review, recent advances on the development of carbon-based and immobilized organic amines-based CO2 adsorbents are summarized, the selection of these particular categories of materials is because they are among the most developed low temperature (<100 oC CO2 adsorbents up to date, which showed important potential for practical deployment at pilot-scale in the near future. Preparation protocols, adsorption behaviors as well as pros and cons of each type of the adsorbents are presented, it was concluded that encouraging results have been achieved already, however, the development of more effective adsorbents for CO2 capture remains challenging and further innovations in the design and synthesis of adsorbents are needed.
Gaussian maximally multipartite entangled states
Facchi, Paolo; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio
2009-01-01
We introduce the notion of maximally multipartite entangled states (MMES) in the context of Gaussian continuous variable quantum systems. These are bosonic multipartite states that are maximally entangled over all possible bipartitions of the system. By considering multimode Gaussian states with constrained energy, we show that perfect MMESs, 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 MMESs and their frustration for n <= 7.
Masaaki Teramoto; Satoshi Kitada; Satoshi Shimizu; Nobuaki Ohnishi; Hideto Matsuyama; Norifumi Matsumiya; Miho Nakamura; Kazuhiro Okabe; Hiroshi Mano [Kyoto Institute of Technology, Kyoto (Japan)
2005-07-01
A novel facilitated transport membrane module for gas separation is proposed in which a carrier solution is forced to permeate the membrane. Both a feed gas and a carrier solution are supplied to the feed side (high pressure side) of the capillary ultrafiltration membrane module and flow upward. Most of the carrier solution which contains dissolved CO{sub 2} permeates the membrane to the permeate side (low-pressure side), where the solution liberates CO{sub 2} to become a lean solution, and the lean solution is returned to the lumen of the capillary module by a pump. In this study, we performed experiments at several operational conditions by using diethanolamine (DEA) and 2,3-diaminopropionic acid (DAPA) as carriers. The feed side pressure was about 1 atm and the permeate side pressure was about 0.05 atm. CO{sub 2} in the feed gas was successfully enriched to 97.1-99.9% by one-stage separation. When the CO{sub 2} mole fraction in the feed was 0.05, the CO{sub 2} permeance and the CO{sub 2}/N{sub 2} selectivity were 8.9-9.4 x 10{sup -4} mol m{sup -2} s{sup -1} kPa{sup -1} and 1020-2320, respectively, and the CO{sub 2} recovery was 72-76 %. The energy required for CO{sub 2} capture, enrichment and liquefaction was about 0.27kWh kgCO{sub 2}{sup -1}, which is much lower than those by using polymeric membranes, conventional gas absorption processes consisting of absorption and stripping column. The proposed process is promising for the CO{sub 2} recovery with low energy consumption. 6 refs., 4 figs., 1 tab.
Pickard, Paul S.; Kataoka, Dawn; Reno, Marissa Devan; Malczynski, Leonard A.; Peplinski, William J.; Roach, Jesse D.; Brainard, James Robert; West, Todd H.; Schoenwald, David Alan
2009-12-01
An initial version of a Systems Dynamics (SD) modeling framework was developed for the analysis of a broad range of energy technology and policy questions. The specific question selected to demonstrate this process was 'what would be the carbon and import implications of expanding nuclear electric capacity to provide power for plug in hybrid vehicles?' Fifteen SNL SD energy models were reviewed and the US Energy and Greenhouse gas model (USEGM) and the Global Nuclear Futures model (GEFM) were identified as the basis for an initial modeling framework. A basic U.S. Transportation model was created to model U.S. fleet changes. The results of the rapid adoption scenario result in almost 40% of light duty vehicles being PHEV by 2040 which requires about 37 GWy/y of additional electricity demand, equivalent to about 25 new 1.4 GWe nuclear plants. The adoption rate of PHEVs would likely be the controlling factor in achieving the associated reduction in carbon emissions and imports.
Profit maximization mitigates competition
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...
Knoop, S; Morgenstern, R; Hoekstra, R
2004-01-01
One-electron removal in the p+Na collision system has been investigated at low energy (4-25 keV) by means of recoil ion momentum spectroscopy. The focus will be on the contribution of one-electron capture from the Na 2p inner shell into the hydrogen ground state, thereby leaving the Na+ target ion
Cho, H J; Yamanoto, S; Fujita, Y; Kim, G Y; Ko, I S; Cho, M H; Namkung, W; Chang, J H; Ko, S K
1999-01-01
The capture cross-sections of Dy and Hf were measured in the energy region from 0.003 eV to 50 keV by using the neutron time-of-flight method at the 46 MeV electron linear accelerator of the Research Reactor Institute, Kyoto University. An assembly of Bi sub 4 Ge sub 3 O sub 1 sub 2 (BGO) scintillators, which was placed at a distance of 12.7 +- 0.02 m from the neutron source, was employed as a total absorption detector for the prompt capture gamma-ray measurement on the sample. In order to determine the neutron flux impinging on a capture sample, we used a Sm(n,gamma) reaction for thermal neutrons and the sup 1 sup 0 B(n,alpha gamma) reaction for neutrons from 0.003 eV to 50 keV. The absolute capture yield for the sample was obtained from the saturated resonance data at a large resonance of the sample. For the capture cross-section of Dy, the existing experimental data and the evaluated data in ENDF/B-VI and JEF-2.2 are closed to the present result. For the Hf capture cross-section, the previous experimental ...
Liu, Jing-Jing; Gu, Wei-Min
2016-06-01
Based on the relativistic mean-field effective interactions theory, and the Lai dong model, we discuss the influences of superstrong magnetic fields (SMFs) on electron Fermi energy, nuclear blinding energy, and single-particle level structure in magnetar surfaces. Using the Shell-Model Monte Carlo method and the Random Phase Approximation theory, we analyze the neutrino energy loss rates (NELRs) by electron capture for iron group nuclei in SMFs. First, when B 12 100, the NELRs decrease by more than three orders of magnitude (e.g., at T 9 = 15.53 for 52-61Fe, 55-60Co, and 56-63Ni). Second, for a certain value of magnetic field and temperature, the NELRs increase by more than four orders of magnitude when {ρ }7≤slant {10}3, but as the density increases (i.e., when {ρ }7\\gt {10}3), there is almost no influence on the density of NELRs. For the density around {ρ }7={10}2, there is an abrupt increase in NELRs when B 12 ≥ 103.5. Such jumps are an indication that the underlying shell structure has changed due to single-particle behavior by SMFs. Finally, we compare our NELRs with those of Fuller et al. (FFN) and Nabi & Klapdor-Kleingrothaus (NKK). For the case without SMFs, one finds that our rates for certain nuclei are close to about five orders of magnitude lower than FFN and NKK at relativistic low temperatures (e.g., T 9 = 1). However, at a relativistic high temperature (e.g., T 9 = 3), our results are in good agreement with NKK, but about one order of magnitude lower than FFN. For the case with SMFs, our NELRs for some iron group nuclei can be about five orders of magnitude higher than those of FFN and NKK. (Note that B 12, T 9, and ρ 7 are in units of 1012 G, 109 K, and {10}7 {{g}} {{cm}}-3, respectively.)
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)
Optimising the Target and Capture Sections of the Neutrino Factory
Hansen, Ole Martin
2016-01-01
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 accel...
Maximally incompatible quantum observables
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.
Nandi, Shyamapada; Collins, Sean; Chakraborty, Debanjan; Banerjee, Debasis; Thallapally, Praveen K; Woo, Tom K; Vaidhyanathan, Ramanathan
2017-02-08
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·DMF], that has the lowest PE for postcombustion CO2 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.
LIU Jing-Jing; LUO Zhi-Quan
2007-01-01
Based on the p-f shell model, the neutrino energy loss rates for nucleus 56Mn, 56Fe, 56Co and 56Ni in the electron capture process are canvassed in and not in a strong electron screening. The results show that the neutrino energy loss rates for 56Mn, 56Fe, 56Co and 56Ni decrease about 15%, 10%, 60% and 1 order of magnitude correspondinglyat the temperature T9 = 15 and even debase 2 orders of magnitude at the temperature T9 = 1.
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.
Endt, P.M.
1956-01-01
Capture reactions will be considered here from the viewpoint of the nuclear spectroscopist. Especially important to him are the capture of neutrons, protons, and alpha particles, which may proceed through narrow resonances, offering a well defined initial state for the subsequent deexcitation proces
Parker, Andrew M.; 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...
Maximization, learning, and economic behavior.
Erev, Ido; Roth, Alvin E
2014-07-22
The rationality assumption that underlies mainstream economic theory has proved to be a useful approximation, despite the fact that systematic violations to its predictions can be found. That is, the assumption of rational behavior is useful in understanding the ways in which many successful economic institutions function, although it is also true that actual human behavior falls systematically short of perfect rationality. We consider a possible explanation of this apparent inconsistency, suggesting that mechanisms that rest on the rationality assumption are likely to be successful when they create an environment in which the behavior they try to facilitate leads to the best payoff for all agents on average, and most of the time. Review of basic learning research suggests that, under these conditions, people quickly learn to maximize expected return. This review also shows that there are many situations in which experience does not increase maximization. In many cases, experience leads people to underweight rare events. In addition, the current paper suggests that it is convenient to distinguish between two behavioral approaches to improve economic analyses. The first, and more conventional approach among behavioral economists and psychologists interested in judgment and decision making, highlights violations of the rational model and proposes descriptive models that capture these violations. The second approach studies human learning to clarify the conditions under which people quickly learn to maximize expected return. The current review highlights one set of conditions of this type and shows how the understanding of these conditions can facilitate market design.
Fleming, P.; Scholbrock, A.; Wright, A.
2014-11-01
Presented at the Nordic Wind Power Conference on November 5, 2014. This presentation describes field-test campaigns performed at the National Wind Technology Center in which lidar technology was used to improve the yaw alignment of the Controls Advanced Research Turbine (CART) 2 and CART3 wind turbines. The campaigns demonstrated that whether by learning a correction function to the nacelle vane, or by controlling yaw directly with the lidar signal, a significant improvement in power capture was demonstrated.
Ming Yi WANG; Guo ZHAO
2005-01-01
A right R-module E over a ring R is said to be maximally injective in case for any maximal right ideal m of R, every R-homomorphism f : m → E can be extended to an R-homomorphism f' : R → E. In this paper, we first construct an example to show that maximal injectivity is a proper generalization of injectivity. Then we prove that any right R-module over a left perfect ring R is maximally injective if and only if it is injective. We also give a partial affirmative answer to Faith's conjecture by further investigating the property of maximally injective rings. Finally, we get an approximation to Faith's conjecture, which asserts that every injective right R-module over any left perfect right self-injective ring R is the injective hull of a projective submodule.
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.
Brüstle, Thomas; Pérotin, Matthieu
2012-01-01
Maximal green sequences are particular sequences of quiver mutations which were introduced by Keller in the context of quantum dilogarithm identities and independently by Cecotti-Cordova-Vafa in the context of supersymmetric gauge theory. Our aim is to initiate a systematic study of these sequences from a combinatorial point of view. Interpreting maximal green sequences as paths in various natural posets arising in representation theory, we prove the finiteness of the number of maximal green sequences for cluster finite quivers, affine quivers and acyclic quivers with at most three vertices. We also give results concerning the possible numbers and lengths of these maximal green sequences. Finally we describe an algorithm for computing maximal green sequences for arbitrary valued quivers which we used to obtain numerous explicit examples that we present.
Belkic, Dzevad
1989-01-01
Total cross sections are computed for electron capture from the ground states of H and He by fast protons using the Corrected first-Born (CB1) approximation. Particular emphasis is given to the formation of atomic hydrogen in excited states 2s, 2p, 3s, 3p, 3d and 4s for which experimental data are available. Detailed comparisons with the measurements are carried out, with the purpose of assessing the validity and utility of the CB1 method for prediction of state-selective cross sections.
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...
Uddin, M.S. [Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, GPO Box No. 3787, Savar, Dhaka 1000 (Bangladesh)], E-mail: shuza88@yahoo.co.in; Chowdhury, M.H. [Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, GPO Box No. 3787, Savar, Dhaka 1000 (Bangladesh); Department of Physics, Jahangirnagar University, Savar, Dhaka (Bangladesh); Hossain, S.M.; Latif, Sk.A.; Hafiz, M.A.; Islam, M.A.; Zakaria, A.K.M.; Yunus, S.M. [Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, GPO Box No. 3787, Savar, Dhaka 1000 (Bangladesh); Azharul Islam, S.M. [Department of Physics, Jahangirnagar University, Savar, Dhaka (Bangladesh)
2008-08-15
The neutron capture cross-section for the {sup 71}Ga(n, {gamma}){sup 72}Ga reaction at 0.0536 eV energy was measured using activation technique based on TRIGA Mark-II research reactor. The {sup 197}Au(n, {gamma}){sup 198}Au monitor reaction was used to determine the effective neutron flux. Neutron absorption and {gamma}-ray attenuation in gallium oxide pellet were corrected in determination of cross-section. The cross-section for the above reaction at 0.0536 eV amounts to 2.75 {+-} 0.14 b. As far as we know there are no experimental data available at our investigated energy. So far we are the first, who carried out experiment with 0.0536 eV neutrons for cross-section measurement. The present result is larger than that of JENDL-3.3, but consistent within the uncertainty range. The value of ENDF/B-VII is higher than this work. The result of this work will be useful to observe energy dependence of neutron capture cross-sections.
Novel Flow Sheet for Low Energy CO_{2} Capture Enabled by Biocatalyst Delivery System
Reardon, John; Shaffer, Alex; Vaysman, Vladimir
2015-02-01
This report documents a preliminary Techno-Economic Assessment (TEA) for processes utilizing Akermin’s second generation biocatalyst delivery system to enhance AKM24, a non- volatile salt solution for CO_{2} capture. Biocatalyst enhanced AKM24 offers the potential to reduce the cost of CO_{2} capture in flue gas applications due to its improved equilibrium and stoichiometric properties that result in double the absorption capacity relative to previously demonstrated biocatalyst enhanced solvents. The study assumes a new supercritical pulverized coal fired power plant with a net output of 550 MWe after 90% CO_{2} capture and uses the June 2011 cost basis (August 2012 update of Bituminous Baseline Study, or BBS). Power plant modeling, capital cost review, and economic calculations were provided by WorleyParsons. Rate-based CO2 capture process modeling and equipment sizing was performed by Akermin using AspenPlus® V8.4, customized to accurately predict thermodynamics, kinetics, and physical properties of the AKM-24 solvent based on available laboratory data. Equipment capital costs were estimated using Aspen Process Economic Analyzer™ which compared well with published baseline cost estimates. Quotes of equipment costs and power consumption for vacuum blower and CO_{2} compression equipment were also provided by Man Diesel & Turbo. Three process scenarios were examined for Akermin biocatalyst enhanced solvent systems including: Case-1A: an absorption-desorption system operated with a reboiler pressure of 0.16 bara (60°C); Case-2A: an absorption-desorption system with moderate vacuum assisted regeneration at 0.40 bara (80°C); and finally, Case-2B: a conventional absorption-desorption system with near atmospheric pressure regeneration at 1.07 bara (105°C). The estimated increases in cost of electricity (ICOE) for these cases were $58.1/MWh, $47.3/MWh and $46.4/MWh, respectively. Case 2B had the best results for this analysis
Pazirandeh, Ali [Physics Department, University of Tehran, Tehran (Iran, Islamic Republic of) and Institute for Theoretical and Applied Physics, Tabriz (Iran, Islamic Republic of)]. E-mail: paziran@ut.ac.ir; Azizi, Maryam [Physics Department, University of Tehran, Tehran (Iran, Islamic Republic of); Institute for Theoretical and Applied Physics, Tabriz (Iran, Islamic Republic of); Farhad Masoudi, S. [Physics Department, University of Tehran, Tehran (Iran, Islamic Republic of); Institute for Theoretical and Applied Physics, Tabriz (Iran, Islamic Republic of)
2006-01-01
Among many conventional techniques, nuclear techniques have shown to be faster, more reliable, and more effective in detecting explosives. In the present work, neutrons from a 5 Ci Am-Be neutron source being in water tank are captured by elements of soil and landmine (TNT), namely {sup 14}N, H, C, and O. The prompt capture gamma-ray spectrum taken by a NaI (Tl) scintillation detector indicates the characteristic photo peaks of the elements in soil and landmine. In the high-energy region of the gamma-ray spectrum, besides 10.829 MeV of {sup 15}N, single escape (SE) and double escape (DE) peaks are unmistakable photo peaks, which make the detection of concealed explosive possible. The soil has the property of moderating neutrons as well as diffusing the thermal neutron flux. Among many elements in soil, silicon is more abundant and {sup 29}Si emits 10.607 MeV prompt capture gamma-ray, which makes 10.829 MeV detection difficult. The Monte Carlo simulation was used to adjust source-target-detector distances and soil moisture content to yield the best result. Therefore, we applied MCNP4C for configuration very close to reality of a hidden landmine in soil.
Radosz, M.; Hu, X.D.; Krutkramelis, K.; Shen, Y.Q. [University of Wyoming, Laramie, WY (United States)
2008-05-15
A low-pressure Carbon Filter Process (patent pending) is proposed to capture carbon dioxide (CO{sub 2}) from flue gas. This filter is filled with a low-cost carbonaceous sorbent, such as activated carbon or charcoal, which has a high affinity (and, hence, high capacity) to CO{sub 2} but not to nitrogen (N{sub 2}). This, in turn, leads to a high CO{sub 2}/N{sub 2} selectivity, especially at low pressures. The Carbon Filter Process proposed in this work can recover at least 90% of flue-gas CO{sub 2} of 90%+ purity at a fraction of the cost normally associated with the conventional amine absorption process. The Carbon Filter Process requires neither expensive materials nor flue-gas compression or refrigeration, and it is easy to heat integrate with an existing or grassroots power plant without affecting the cost of the produced electricity too much. An abundant supply of low-cost CO{sub 2} from electricity producers is good news for enhanced oil recovery (EOR) and enhanced coal-bed methane recovery (ECBMR) operators, because it will lead to higher oil and gas recovery rates in an environmentally sensitive manner. A CO{sub 2}-rich mixture that contains some nitrogen is much less expensive to separate from flue-gas than pure CO{sub 2}; therefore, mixed CO{sub 2}/N{sub 2}-EOR and CO{sub 2}/N{sub 2}-ECBMR methods are proposed to maximize the overall carbon capture and utilization efficiency.
Zhang, S.
2016-01-01
As global energy consumption increased to 389 EJ by 2013, while the global energy-related CO2 emissions increased by over 50%, to 32.2 Gt in 2014. This growth is driven mostly by increased industrial production in developing countries. By now already two thirds of CO2 emissions budget for limiting
Zhang, S.
2016-01-01
As global energy consumption increased to 389 EJ by 2013, while the global energy-related CO2 emissions increased by over 50%, to 32.2 Gt in 2014. This growth is driven mostly by increased industrial production in developing countries. By now already two thirds of CO2 emissions budget for limiting g
Salmon, Sonja [Novozymes North America, Inc., Franklinton, NC (United States); House, Alan [Novozymes North America, Inc., Franklinton, NC (United States); Liu, Kun [Univ. of Kentucky, Lexington, KY (United States); Frimpong, Reynolds [Univ. of Kentucky, Lexington, KY (United States); Liu, Kunlei [Univ. of Kentucky, Lexington, KY (United States); Freeman, Charles [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Whyatt, Greg [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Slater, Jonathan [Doosan Babcock, Renfew (United Kingdom); Fitzgerald, David [Doosan Babcock, Renfew (United Kingdom)
2015-08-31
An integrated bench-scale system combining the attributes of the bio-renewable enzyme carbonic anhydrase (CA) with low-enthalpy CO2 absorption solvents and vacuum regeneration was designed, built and operated for 500 hours using simulated flue gas. The objective was to develop a CO2 capture process with improved efficiency and sustainability when compared to NETL Case 10 monoethanolamine (MEA) scrubbing technology. The use of CA accelerates inter-conversion between dissolved CO2 and bicarbonate ion to enhance CO2 absorption, and the use of low enthalpy CO2 absorption solvents makes it possible to regenerate the solvent at lower temperatures relative to the reference MEA-based solvent. The vacuum regeneration-based integrated bench-scale system operated successfully for an accumulated 500 hours using aqueous 23.5 wt% K2CO3-based solvent containing 2.5 g/L enzyme to deliver an average 84% CO2 capture when operated with a 20% enzyme replenishment rate per ~7 hour steady-state run period. The total inlet gas flow was 30 standard liters per minute with 15% CO2 and 85% N2. The absorber temperature was 40°C and the stripper operated under 35 kPa pressure with an approximate 77°C stripper bottom temperature. Tests with a 30°C absorber temperature delivered >90% capture. On- and off-line operational measurements provided a full process data set, with recirculating enzyme, that allowed for enzyme replenishment and absorption/desorption kinetic parameter calculations. Dissolved enzyme replenishment and conventional process controls were demonstrated as straightforward approaches to maintain system performance. Preliminary evaluation of a novel flow-through ultrasonically enhanced regeneration system was also conducted, yet resulted in CO2 release within the range of temperature-dependent release, and further work would be needed to validate the benefits of ultrasonic enhanced stripping. A full technology assessment was completed in which four techno-economic cases for
Rudiger Bubner
1998-12-01
Full Text Available Even though the maxims' theory is not at thecenter of Kant's ethics, it is the unavoidable basis of the categoric imperative's formulation. Kant leanson the transmitted representations of modem moral theory. During the last decades, the notion of maxims has deserved more attention, due to the philosophy of language's debates on rules, and due to action theory's interest in this notion. I here by brietly expound my views in these discussions.
Power Generation Technology Using CO2 Capture Energy Storage%利用捕捉的 CO2贮能发电技术研究
金家敏
2016-01-01
碳捕捉技术是指通过一定的方法，将工业生产中产生的CO2分离出来进行储存和利用的工艺和技术。论述了利用捕捉的二氧化碳贮能发电和生产煤气的技术，包括生产流程、电热煤气发生炉、技术可行性、经济效益等，并对碳气化贮能经济效益进行估算，得到碳气化贮能不仅不要外电补足，而且还有多余的电能供应它用，有很大的优越性。%Carbon‐capture technology is to separate CO2 generated during the industrial production for storage and utilization .This paper discusses the technology of applying the captured CO2 for power generation and coal gas production ,including production process ,electric gas furnace ,technical feasibility and economic benefit etc .,and estimates the economic benefit of carbon gasification energy storage .And it is concluded that carbon gasification energy storage can not only need no redundant power supply ,but also exhibits great advantages .
Hatzell, Marta C.
2014-01-01
Currently, there is an enormous amount of energy available from salinity gradients, which could be used for clean hydrogen production. Through the use of a favorable oxygen reduction reaction (ORR) cathode, the projected electrical energy generated by a single pass ammonium bicarbonate reverse electrodialysis (RED) system approached 78 W h m-3. However, if RED is operated with the less favorable (higher overpotential) hydrogen evolution electrode and hydrogen gas is harvested, the energy recovered increases by as much ∼1.5× to 118 W h m-3. Indirect hydrogen production through coupling an RED stack with an external electrolysis system was only projected to achieve 35 W h m-3 or ∼1/3 of that produced through direct hydrogen generation.
Hatzell, Marta C; Ivanov, Ivan; Cusick, Roland D; Zhu, Xiuping; Logan, Bruce E
2014-01-28
Currently, there is an enormous amount of energy available from salinity gradients, which could be used for clean hydrogen production. Through the use of a favorable oxygen reduction reaction (ORR) cathode, the projected electrical energy generated by a single pass ammonium bicarbonate reverse electrodialysis (RED) system approached 78 W h m(-3). However, if RED is operated with the less favorable (higher overpotential) hydrogen evolution electrode and hydrogen gas is harvested, the energy recovered increases by as much ~1.5× to 118 W h m(-3). Indirect hydrogen production through coupling an RED stack with an external electrolysis system was only projected to achieve 35 W h m(-3) or ~1/3 of that produced through direct hydrogen generation.
Oliver, A.; Wootton, L.R. [City Univ., London (United Kingdom); Prats, J. [Ecotecnia SCC Ltd. (United Kingdom)
1997-06-01
City University and Ecotecnia have recently completed a project funded by the European Union Joule II programme on the optimisation and control of wind turbines. The blade set of a 150 kW stall regulated wind turbine was modified with air jet vortex generators and tested at full scale. This was done primarily to increase its energy yield by reducing energy loss in the region of the power curve `knee`, but also to allow a degree of power regulation in high wind speeds. Of these, the former has so far been demonstrated successfully. (author)
王蕾; 李娜; 曾鸣
2013-01-01
Energy storage systems play an important role in taking full advantage of renewable energy and improving the economic benefits of microgrids.Effective energy strategies need to be applied to realize the profit maximization.Considering the uncertainty and volatility of the electricity prices,the objective function of decision-making process is established,and the dynamic programming model to maximize the profits by energy storage systems is presented.The results show that the model can promote the development of energy storage technologies and provide greater profit margins.The impacts of price and energy storage strategy on the profits are analyzed by taking an energy storage system in microgrid as an example,and the feasibility and rationality of the proposed method are proven.%微网储能系统对于充分利用可再生能源、提高微网经济效益发挥着重要作用,为实现经济利润的最大化,需采取合理有效的储能策略.在考虑电价不确定性和波动性的基础上,建立决策过程的目标函数,并提出通过储能系统实现利润最大化的动态规划模型.研究结果表明,采用该模型能更好地推进储能技术发展,提供更大的利润空间.以一个微网储能系统为例,分析价格和储能策略对系统利润的影响,验证了所建立模型的可行性和合理性.
2011-12-07
... proposed information collection requirement described below will be submitted to the Office of Management... green retrofits and creating energy efficient units. In addition to the direct support of HUD APG 13... (2577-New) and should be sent to: HUD Desk Officer Office of Management and Budget, New Executive...
Prokhorova, E V; Itkis, M G; Kondratev, N A; Kozulin, E M; Krupa, L; Oganessian, Yu T; Pashkevich, V V; Pokrovsky, I V; Rusanov, A Ya; Oganessian, Yu.Ts.
2003-01-01
The capture-fission cross-sections in an energy range of 206-242 MeV of 48Ca-projectiles and mass-energy distributions (MEDs) of reaction products in an energy range of 211-242 MeV have been measured in the 48Ca+208Pb reaction using the double-arm time-of-flight spectrometer CORSET. The MEDs of fragments for heated fission were shown to consist of two components. One component, which is due to classical fusion-fission, is associated with the symmetric fission of the 256No compound nucleus. The other component, which appears as ''shoulders'', is associated with the quasi-fission process and can be named ''quasi-fission shoulders''. Those quasi-fission shoulders enclose light fragments whose masses are 60-90 a.m.u. The total kinetic energy (TKE) of the fragments that belong to the shoulders is higher than the value expected for a classical fusion-fission process. We have come to the conclusion that in quasi-fission, spherical shells with Z=28 and N=50 play a great role. It has also been demonstrated that the pr...
Rushmeier, Holly E.
2005-01-01
For computer graphics applications, capturing the appearance parameters of objects (reflectance, transmittance and small scale surface structures), is as important as capturing the overall shape. We briefly review recent approaches developed by the computer graphics community to solve this problem. Excellent results have been obtained by various researchers measuring spatially varying reflectance functions for some classes of objects. We will consider some challenges from two of the remaining problematic classes of objects. First we will describe our experience scanning and modeling the throne of Tutankhamen. The major difficulties in this case were that the base shape was a highly detailed non-convex geometry with complex topology, and the shape was covered by optically uncooperative gold and silver. Then we will discuss some observations from our ongoing project to scan and model historic buildings on the Yale campus. The major difficulties in this second case are quantity of data and the lack of control over acquisition conditions.
Salahinejad, Maryam; Le, Tu C; Winkler, David A
2013-01-28
Accurate computational prediction of melting points and aqueous solubilities of organic compounds would be very useful but is notoriously difficult. Predicting the lattice energies of compounds is key to understanding and predicting their melting behavior and ultimately their solubility behavior. We report robust, predictive, quantitative structure-property relationship (QSPR) models for enthalpies of sublimation, crystal lattice energies, and melting points for a very large and structurally diverse set of small organic compounds. Sparse Bayesian feature selection and machine learning methods were employed to select the most relevant molecular descriptors for the model and to generate parsimonious quantitative models. The final enthalpy of sublimation model is a four-parameter multilinear equation that has an r(2) value of 0.96 and an average absolute error of 7.9 ± 0.3 kJ.mol(-1). The melting point model can predict this property with a standard error of 45° ± 1 K and r(2) value of 0.79. Given the size and diversity of the training data, these conceptually transparent and accurate models can be used to predict sublimation enthalpy, lattice energy, and melting points of organic compounds in general.
Cowlin, S.; Cochran, J.; Cox, S.; Davison, C.; van der Gaast, Y.
2012-08-01
Low emission development strategies (LEDS) articulate policies and implementation plans that enable countries to advance sustainable, climate-resilient development and private sector growth while significantly reducing the greenhouse gas (GHG) emissions traditionally associated with economic growth. In creating a LEDS, policy makers often have access to information on abatement potential and costs for clean energy technologies, but there is a scarcity of economy-wide approaches for evaluating and presenting information on other dimensions of importance to development, such as human welfare, poverty alleviation, and energy security. To address this shortcoming, this paper proposes a new tool for communicating development benefits to policy makers as part of a LEDS process. The purpose of this tool is two-fold: 1. Communicate development benefits associated with each clean energy-related intervention; 2. Facilitate decision-making on which combination of interventions best contributes to development goals. To pilot this tool, the authors created a visual using data on developmental impacts identified through the Technology Needs Assessment (TNA) project in Montenegro. The visual will then be revised to reflect new data established through the TNA that provides information on cost, GHG mitigation, as well as the range and magnitude of developmental impacts.
Smith, Peter F
2016-01-01
Sterile neutrinos in the keV mass range may constitute the galactic dark matter. Various proposed direct detection and laboratory searches are reviewed. The most promising method in the near future is complete energy-momentum reconstruction of individual beta-decay or K-capture events, using atoms suspended in a magneto-optical trap. A survey of suitable isotopes is presented, together with the measurement precision required in a typical experimental configuration. It is concluded that among the most promising are the K-capture isotopes 131Cs, which requires measurement of an X-ray and several Auger electrons in addition to the atomic recoil, and 7Be which has only a single decay product but needs development work to achieve a trapped source. A number of background effects are discussed. It is concluded that sterile neutrinos with masses down to the 5-10 keV region would be detectable, together with relative couplings down to the level 10-10-10-11 in a 1-2 year running time.
Beretta, G P
2001-01-01
In view of the recent quest for well-behaved nonlinear extensions of the traditional Schroedinger-von Neumann unitary dynamics that could provide fundamental explanations of recent experimental evidence of loss of quantum coherence at the microscopic level, in this paper, together with a review of the general features of the nonlinear quantum (thermo)dynamics I proposed in a series of papers [see references in G.P. Beretta, Found.Phys. 17, 365 (1987)], I show its exact equivalence with the maximal-entropy-production variational-principle formulation recently derived in S. Gheorghiu-Svirschevski, Phys.Rev. A 63, 022105 (2001). In addition, based on the formalism of general interest I developed for the analysis of composite systems, I show how the variational derivation can be extended to the case of a composite system to obtain the general form of my equation of motion, that turns out to be consistent with the demanding requirements of strong separability. Moreover, I propose a new intriguing fundamental ansat...
Xiao, Yan; Li, Yaoyu; Rotea, Mario A.
2016-09-01
The primary objective in below rated wind speed (Region 2) is to maximize the turbine's energy capture. Due to uncertainty, variability of turbine characteristics and lack of inexpensive but precise wind measurements, model-free control strategies that do not use wind measurements such as Extremum Seeking Control (ESC) have received significant attention. Based on a dither-demodulation scheme, ESC can maximize the wind power capture in real time despite uncertainty, variabilities and lack of accurate wind measurements. The existing work on ESC based wind turbine control focuses on power capture only. In this paper, a multi-objective extremum seeking control strategy is proposed to achieve nearly optimum wind energy capture while decreasing structural fatigue loads. The performance index of the ESC combines the rotor power and penalty terms of the standard deviations of selected fatigue load variables. Simulation studies of the proposed multi-objective ESC demonstrate that the damage-equivalent loads of tower and/or blade loads can be reduced with slight compromise in energy capture.
Rafiq, Muhammad Khalid; Bachmann, Robert Thomas; Rafiq, Muhammad Tariq; Shang, Zhanhuan; Joseph, Stephen; Long, Ruijun
2016-01-01
This study examined the influence of pyrolysis temperature on biochar characteristics and evaluated its suitability for carbon capture and energy production. Biochar was produced from corn stover using slow pyrolysis at 300, 400 and 500°C and 2 hrs holding time. The experimental biochars were characterized by elemental analysis, BET, FTIR, TGA/DTA, NMR (C-13). Higher heating value (HHV) of feedstock and biochars was measured using bomb calorimeter. Results show that carbon content of corn stover biochar increased from 45.5% to 64.5%, with increasing pyrolysis temperatures. A decrease in H:C and O:C ratios as well as volatile matter, coupled with increase in the concentration of aromatic carbon in the biochar as determined by FTIR and NMR (C-13) demonstrates a higher biochar carbon stability at 500°C. It was estimated that corn stover pyrolysed at 500°C could provide of 10.12 MJ/kg thermal energy. Pyrolysis is therefore a potential technology with its carbon-negative, energy positive and soil amendment benefits thus creating win- win scenario.
Muhammad Khalid Rafiq
Full Text Available This study examined the influence of pyrolysis temperature on biochar characteristics and evaluated its suitability for carbon capture and energy production. Biochar was produced from corn stover using slow pyrolysis at 300, 400 and 500°C and 2 hrs holding time. The experimental biochars were characterized by elemental analysis, BET, FTIR, TGA/DTA, NMR (C-13. Higher heating value (HHV of feedstock and biochars was measured using bomb calorimeter. Results show that carbon content of corn stover biochar increased from 45.5% to 64.5%, with increasing pyrolysis temperatures. A decrease in H:C and O:C ratios as well as volatile matter, coupled with increase in the concentration of aromatic carbon in the biochar as determined by FTIR and NMR (C-13 demonstrates a higher biochar carbon stability at 500°C. It was estimated that corn stover pyrolysed at 500°C could provide of 10.12 MJ/kg thermal energy. Pyrolysis is therefore a potential technology with its carbon-negative, energy positive and soil amendment benefits thus creating win- win scenario.
Rafiq, Muhammad Khalid; Bachmann, Robert Thomas; Rafiq, Muhammad Tariq; Shang, Zhanhuan; Joseph, Stephen; Long, Ruijun
2016-01-01
This study examined the influence of pyrolysis temperature on biochar characteristics and evaluated its suitability for carbon capture and energy production. Biochar was produced from corn stover using slow pyrolysis at 300, 400 and 500°C and 2 hrs holding time. The experimental biochars were characterized by elemental analysis, BET, FTIR, TGA/DTA, NMR (C-13). Higher heating value (HHV) of feedstock and biochars was measured using bomb calorimeter. Results show that carbon content of corn stover biochar increased from 45.5% to 64.5%, with increasing pyrolysis temperatures. A decrease in H:C and O:C ratios as well as volatile matter, coupled with increase in the concentration of aromatic carbon in the biochar as determined by FTIR and NMR (C-13) demonstrates a higher biochar carbon stability at 500°C. It was estimated that corn stover pyrolysed at 500°C could provide of 10.12 MJ/kg thermal energy. Pyrolysis is therefore a potential technology with its carbon-negative, energy positive and soil amendment benefits thus creating win- win scenario. PMID:27327870
Dias, S. [Engiciclo - Environmental Engineering Ltd, Avenida Capitao Melecas 99 C/V Esq, 2815-099 Alverca (Portugal); Teixeira, E.; Kroff, P. [Simbiente - Environmental Engineering and Management Ltd, Praca Paulo Vidal, n 21, 4715-245 Braga (Portugal); Laia, C. [CEEETA - Centro de Estudos em Economia da Energia dos Transportes e do Ambiente, Rua Dr. Antonio Candido, n10 - 1, 1050-076 Lisboa (Portugal); Nogueira, R.; Brito, A.G. [Institute of Biotechnology and Bioengineering, Department of Biological Engineering, University of Minho, Campus de Gualtar 4710-057 Braga, (Portugal)
2008-07-01
The present work presents some of the results of five reports developed in the scope of optimization feasibility studies carried out at 6 small- and medium-sized wastewater treatment plants (WWTP) in Portugal. These 6 WWTP are operated by five companies that belong to the Aguas de Portugal holding. The objective of the studies was twofold: to assess to which extent the production of biogas could be increased by means of operational modifications and/or by the implementation of co-digestion regimes; and also to simulate different scenarios for feed-in tariff of electricity taking in account energy prices calculated based upon the DL n. 225/2007 of 11th May. In this way, several codigestion scenarios were defined based upon standard available organic residues. The results obtained showed that the implementation of co-digestion regimes represent a significative potential to increase the production of biogas, in some cases, over 600%. Even though, it was concluded that in some cases the costs of introducing new regimes of energy management were not supported by the increase of energy production, so a scale factor is associated to the revenues. This study contributed to the establishment of specific needs in terms of information management (digester operation, energy production/consumption, strategy for optimisation).
Research and advanced breeding have demonstrated that energy cane possesses all of the attributes desirable in a biofuel feedstock: extremely good biomass yield in a small farming footprint; negative/neutral carbon footprint; maximum outputs from minimum inputs; well-established growing model for fa...
Ricci, P.; Truhlík, E.; Mosconi, B.; Smejkal, J.
2010-06-01
Model dependence of the capture rates of the negative muon capture in deuterium is studied starting from potential models and the weak two-body meson exchange currents constructed in the tree approximation and also from an effective field theory. The tree one-boson exchange currents are derived from the hard pion chiral Lagrangians of the NΔπρωa system. If constructed in conjunction with the one-boson exchange potentials, the capture rates can be calculated consistently. On the other hand, the effective field theory currents, constructed within the heavy baryon chiral perturbation theory, contain a low energy constant d that cannot be extracted from data at the one-particle level nor determined from the first principles. Comparative analysis of the results for the doublet transition rate allows us to extract the constant d.
Park, Hea Jung; So, Monica C; Gosztola, David; Wiederrecht, Gary P; Emery, Jonathan D; Martinson, Alex B F; Er, Süleyman; Wilmer, Christopher E; Vermeulen, Nicolaas A; Aspuru-Guzik, Alán; Stoddart, J Fraser; Farha, Omar K; Hupp, Joseph T
2016-09-28
We demonstrate that thin films of metal-organic framework (MOF)-like materials, containing two perylenediimides (PDICl4, PDIOPh2) and a squaraine dye (S1), can be fabricated by layer-by-layer assembly (LbL). Interestingly, these LbL films absorb across the visible light region (400-750 nm) and facilitate directional energy transfer. Due to the high spectral overlap and oriented transition dipole moments of the donor (PDICl4 and PDIOPh2) and acceptor (S1) components, directional long-range energy transfer from the bluest to reddest absorber was successfully demonstrated in the multicomponent MOF-like films. These findings have significant implications for the development of solar energy conversion devices based on MOFs.
On neutrinoless double electron capture
Drukarev, E G
2016-01-01
We found the probability for the neutrinoless double electron capture in the case of $KK$ capture. We clarified the mechanism of the energy transfer from the nucleus to the bound electrons. This enabled us to obtain the equations for the probability of the $2EC0\
Janusz Brzozowski
2014-05-01
Full Text Available The atoms of a regular language are non-empty intersections of complemented and uncomplemented quotients of the language. Tight upper bounds on the number of atoms of a language and on the quotient complexities of atoms are known. We introduce a new class of regular languages, called the maximally atomic languages, consisting of all languages meeting these bounds. We prove the following result: If L is a regular language of quotient complexity n and G is the subgroup of permutations in the transition semigroup T of the minimal DFA of L, then L is maximally atomic if and only if G is transitive on k-subsets of 1,...,n for 0 <= k <= n and T contains a transformation of rank n-1.
Zafiris, George
2010-08-24
Presentation describes United Technologies Research Center's recent work in green energy systems, including APRA-E project content to create a synthetic analogue of the carbonic anhydrase enzyme and incorporate it into a membrane for CO2 separation from the flue gas of a coal power plant.
Andersen, Klaus Ejner
1985-01-01
Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline with...... to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions....
Winter, Peter
2010-01-01
Measuring the rate of muon capture in hydrogen provides one of the most direct ways to study the axial current of the nucleon. The MuCap experiment uses a negative muon beam stopped in a time projection chamber operated with ultra-pure hydrogen gas. Surrounded by a decay electron detector, the lifetime of muons in hydrogen can be measured to determine the singlet capture rate Lambda_s to a final precision of 1%. The capture rate determines the nucleon's pseudoscalar form factor g_p. A first result, g_p = 7.3 +- 1.1, has been published and the final analysis of the full statistics will reduce the error by a factor of up to 3. Muon capture on the deuteron probes the weak axial current in the two-nucleon system. Within the framework of effective field theories the calculation of such two-nucleon processes involving the axial current requires the knowledge of one additional low energy constant which can be extracted from the doublet capture rate Lambda_d. The same constant then allows to model-independently calcu...
Zak, Michail
2008-01-01
A report discusses an algorithm for a new kind of dynamics based on a quantum- classical hybrid-quantum-inspired maximizer. The model is represented by a modified Madelung equation in which the quantum potential is replaced by different, specially chosen 'computational' potential. As a result, the dynamics attains both quantum and classical properties: it preserves superposition and entanglement of random solutions, while allowing one to measure its state variables, using classical methods. Such optimal combination of characteristics is a perfect match for quantum-inspired computing. As an application, an algorithm for global maximum of an arbitrary integrable function is proposed. The idea of the proposed algorithm is very simple: based upon the Quantum-inspired Maximizer (QIM), introduce a positive function to be maximized as the probability density to which the solution is attracted. Then the larger value of this function will have the higher probability to appear. Special attention is paid to simulation of integer programming and NP-complete problems. It is demonstrated that the problem of global maximum of an integrable function can be found in polynomial time by using the proposed quantum- classical hybrid. The result is extended to a constrained maximum with applications to integer programming and TSP (Traveling Salesman Problem).
On the maximal efficiency of the collisional Penrose process
Leiderschneider, Elly
2015-01-01
The center of mass (CM) energy in a collisional Penrose process - a collision taking place within the ergosphere of a Kerr black hole - can diverge under suitable extreme conditions (maximal Kerr, near horizon collision and suitable impact parameters). We present an analytic expression for the CM energy, refining expressions given in the literature. Even though the CM energy diverges, we show that the maximal energy attained by a particle that escapes the black hole's gravitational pull and reaches infinity is modest. We obtain an analytic expression for the energy of an escaping particle resulting from a collisional Penrose process, and apply it to derive the maximal energy and the maximal efficiency for several physical scenarios: pair annihilation, Compton scattering, and the elastic scattering of two massive particles. In all physically reasonable cases (in which the incident particles initially fall from infinity towards the black hole) the maximal energy (and the corresponding efficiency) are only one o...
Peters, Catherine; Fitts, Jeffrey; Wilson, Elizabeth; Pollak, Melisa; Bielicki, Jeffrey; Bhatt, Vatsal
2013-03-13
This three-year project, performed by Princeton University in partnership with the University of Minnesota and Brookhaven National Laboratory, examined geologic carbon sequestration in regard to CO{sub 2} leakage and potential subsurface liabilities. The research resulted in basin-scale analyses of CO{sub 2} and brine leakage in light of uncertainties in the characteristics of leakage processes, and generated frameworks to monetize the risks of leakage interference with competing subsurface resources. The geographic focus was the Michigan sedimentary basin, for which a 3D topographical model was constructed to represent the hydrostratigraphy. Specifically for Ottawa County, a statistical analysis of the hydraulic properties of underlying sedimentary formations was conducted. For plausible scenarios of injection into the Mt. Simon sandstone, leakage rates were estimated and fluxes into shallow drinking-water aquifers were found to be less than natural analogs of CO{sub 2} fluxes. We developed the Leakage Impact Valuation (LIV) model in which we identified stakeholders and estimated costs associated with leakage events. It was found that costs could be incurred even in the absence of legal action or other subsurface interference because there are substantial costs of finding and fixing the leak and from injection interruption. We developed a model framework called RISCS, which can be used to predict monetized risk of interference with subsurface resources by combining basin-scale leakage predictions with the LIV method. The project has also developed a cost calculator called the Economic and Policy Drivers Module (EPDM), which comprehensively calculates the costs of carbon sequestration and leakage, and can be used to examine major drivers for subsurface leakage liabilities in relation to specific injection scenarios and leakage events. Finally, we examined the competiveness of CCS in the energy market. This analysis, though qualitative, shows that financial
魏炜; 陈嘉; 罗凤章
2016-01-01
In the distribution network island due to faults,in order to improve the power supply capability of intermit⁃tent power generation for important load,some energy storage system with reasonable power path for load is a solution. This paper proposes an optimal capacity allocation method for energy storage based on island searching strategy. The performance of traditional searching method is improved,which is employed to maximize the load value and obtain the sets of all best power paths in the island structure. In the capacity allocation of energy storage,this paper maximizes the power supply efficiency of energy storage by referring to the sets of best power paths. Moreover,the probability distribu⁃tion of load value supported by energy storage is also determined according to the power output duration curve. The sim⁃ulation example verifies that the proposed method can effectively determine the optimal energy storage capacity when the energy storage capacity per unit supports the maximum load value.%在配电网因故障出现的孤岛内，为提高间歇性电源对重要负荷的供电能力，配置一定容量的储能系统并选择合理的供电路径支撑负荷。该文提出了基于孤岛搜索的有源配电网储能容量优化配置方法。在孤岛搜索中对常规方法改进，求得孤岛拓扑约束下所有使得支撑负荷价值最大的供电路径集合，在储能容量优化配置中结合供电路径最大化储能支撑效果，依据电源出力持续曲线确定储能支撑负荷价值的概率分布。仿真算例验证所提方法能有效确定单位储能出力支撑负荷价值最大时的最佳储能容量。
黎灿兵; 王煌; 耿英会; 孙良; 曹一家; 石海清
2014-01-01
Reducing the content of carbon dioxide in air is the key to addressing climate change.Carbon capture and storage is an important measure to reduce carbon dioxide emission.Capturing carbon from ambient air directly needs large amounts of energy.The loads on carbon capture devices are flexible,which to some extent can be driven by intermittent energy. Renewable energy such as wind power and solar energy has great potential for development,which has the characteristics of fluctuation.Using renewable energy to capture carbon from ambient air directly can reduce the concentration of carbon dioxide in the atmosphere.It is a promising way to address global climate change.This paper analyzes the potential of using renewable energy to capture carbon from ambient air directly,and proposes the key technologies of using renewable energy to capture carbon.The planning of using renewable energy to capture carbon is preliminarily studied,and the development trend of carbon capture driven by renewable energy is discussed.%降低空气中二氧化碳的含量是应对气候变化的关键。碳捕集与封存是减少二氧化碳排放量的重要措施。从空气中直接捕碳需要消耗大量能源。捕碳装置负荷是柔性负荷，可以在一定程度上接受波动性能源驱动。风能、太阳能等新能源开发潜力巨大，具有波动性的特点。利用其驱动捕碳装置从空气中直接捕碳，可以降低大气中二氧化碳的浓度，可望成为解决全球气候变化问题的关键途径。文中分析了利用新能源驱动的从空气中直接捕碳的潜力，提出了新能源捕碳的关键技术。对新能源捕碳的规划进行了初步研究，并对利用新能源捕碳的发展趋势进行了展望。
Savitha, D; Sejil, T V; Rao, Shwetha; Roshan, C J; Roshan, C J
2013-01-01
The purpose of the study was to investigate the effect of vocal and instrumental music on various physiological parameters during submaximal exercise. Each subject underwent three sessions of exercise protocol without music, with vocal music, and instrumental versions of same piece of music. The protocol consisted of 10 min treadmill exercise at 70% HR(max) and 20 min of recovery. Minute to minute heart rate and breath by breath recording of respiratory parameters, rate of energy expenditure and perceived exertion levels were measured. Music, irrespective of the presence or absence of lyrics, enabled the subjects to exercise at a significantly lower heart rate and oxygen consumption, reduced the metabolic cost and perceived exertion levels of exercise (P Music having a relaxant effect could have probably increased the parasympathetic activation leading to these effects.
Harris, Michelle A; Jiang, Jianbing; Niedzwiedzki, Dariusz M; Jiao, Jieying; Taniguchi, Masahiko; Kirmaier, Christine; Loach, Paul A; Bocian, David F; Lindsey, Jonathan S; Holten, Dewey; Parkes-Loach, Pamela S
2014-07-01
Biohybrid antennas built upon chromophore-polypeptide conjugates show promise for the design of efficient light-capturing modules for specific purposes. Three new designs, each of which employs analogs of the β-polypeptide from Rhodobacter sphaeroides, have been investigated. In the first design, amino acids at seven different positions on the polypeptide were individually substituted with cysteine, to which a synthetic chromophore (bacteriochlorin or Oregon Green) was covalently attached. The polypeptide positions are at -2, -6, -10, -14, -17, -21, and -34 relative to the 0-position of the histidine that coordinates bacteriochlorophyll a (BChl a). All chromophore-polypeptides readily formed LH1-type complexes upon combination with the α-polypeptide and BChl a. Efficient energy transfer occurs from the attached chromophore to the circular array of 875 nm absorbing BChl a molecules (denoted B875). In the second design, use of two attachment sites (positions -10 and -21) on the polypeptide affords (1) double the density of chromophores per polypeptide and (2) a highly efficient energy-transfer relay from the chromophore at -21 to that at -10 and on to B875. In the third design, three spectrally distinct bacteriochlorin-polypeptides were prepared (each attached to cysteine at the -14 position) and combined in an ~1:1:1 mixture to form a heterogeneous mixture of LH1-type complexes with increased solar coverage and nearly quantitative energy transfer from each bacteriochlorin to B875. Collectively, the results illustrate the great latitude of the biohybrid approach for the design of diverse light-harvesting systems.
Brandes, U; Gaertler, M; Goerke, R; Hoefer, M; Nikoloski, Z; Wagner, D
2006-01-01
Several algorithms have been proposed to compute partitions of networks into communities that score high on a graph clustering index called modularity. While publications on these algorithms typically contain experimental evaluations to emphasize the plausibility of results, none of these algorithms has been shown to actually compute optimal partitions. We here settle the unknown complexity status of modularity maximization by showing that the corresponding decision version is NP-complete in the strong sense. As a consequence, any efficient, i.e. polynomial-time, algorithm is only heuristic and yields suboptimal partitions on many instances.
Maximizing without difficulty: A modified maximizing scale and its correlates
Linda Lai
2010-01-01
This article presents several studies that replicate and extend previous research on maximizing. A modified scale for measuring individual maximizing tendency is introduced. The scale has adequate psychometric properties and reflects maximizers' aspirations for high standards and their preference for extensive alternative search, but not the decision difficulty aspect included in several previous studies. Based on this scale, maximizing is positively correlated with optimism, need for cogniti...
Yanch, Jacquelyn C. (Cambridge, MA); Shefer, Ruth E. (Newton, MA); Klinkowstein, Robert E. (Winchester, MA)
1999-01-01
In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.
Yanch, J.C.; Shefer, R.E.; Klinkowstein, R.E.
1999-11-02
In one embodiment there is provided an application of the {sup 10}B(n,{alpha}){sup 7}Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.
Valverde, Jose Manuel; Medina, Santiago
2017-03-02
This work reports an in situ XRD analysis of whether the calcination/carbonation behavior of natural limestone (CaCO3) is affected by the addition of H2O to the calciner at a very low concentration under relevant Calcium-Looping (CaL) conditions for CO2 capture in coal fired power plants (CFPP) and Thermochemical Energy Storage (TCES) in Concentrated Solar Power plants (CSP). Previous studies have demonstrated that the presence of steam in the calciner at a high concentration yields a significant increase in the reaction rate. However, a further undesired consequence is the serious deterioration of the CaO mechanical strength, which would lead to particle attrition and mass loss in any CaL process based on the use of circulating fluidized beds. The results presented in this manuscript on the time evolution of the wt% and crystallite size of the phases involved in the calcination/carbonation reactions indicate that the calcination rate is still notably increased by the presence of H2O at very low concentrations whereas the reactivity toward carbonation and crystal structure of the formed CaO are not essentially affected, which suggests that the CaO mechanical strength is not impaired. Thus, the benefit of using steam for calcination in the CaL process could be still retained while at the same time particle attrition would not be promoted.
Nease, Jake; Adams, Thomas A.
2014-04-01
In this study, a coal-fuelled integrated solid oxide fuel cell (SOFC) and compressed air energy storage (CAES) system in a load-following power production scenario is discussed. Sixteen SOFC-based plants with optional carbon capture and sequestration (CCS) and syngas shifting steps are simulated and compared to a state-of-the-art supercritical pulverised coal (SCPC) plant. Simulations are performed using a combination of MATLAB and Aspen Plus v7.3. It was found that adding CAES to a SOFC-based plant can provide load-following capabilities with relatively small effects on efficiencies (1-2% HHV depending on the system configuration) and levelized costs of electricity (∼0.35 ¢ kW-1 h-1). The load-following capabilities, as measured by least-squares metrics, show that this system may utilize coal and achieve excellent load-tracking that is not adversely affected by the inclusion of CCS. Adding CCS to the SOFC/CAES system reduces measurable direct CO2 emission to zero. A seasonal partial plant shutdown schedule is found to reduce fuel consumption by 9.5% while allowing for cleaning and maintenance windows for the SOFC stacks without significantly affecting the performance of the system (∼1% HHV reduction in efficiency). The SOFC-based systems with CCS are found to become economically attractive relative to SCPC above carbon taxes of 22 ton-1.
HEMI: Hyperedge Majority Influence Maximization
Gangal, Varun; Narayanam, Ramasuri
2016-01-01
In this work, we consider the problem of influence maximization on a hypergraph. We first extend the Independent Cascade (IC) model to hypergraphs, and prove that the traditional influence maximization problem remains submodular. We then present a variant of the influence maximization problem (HEMI) where one seeks to maximize the number of hyperedges, a majority of whose nodes are influenced. We prove that HEMI is non-submodular under the diffusion model proposed.
Andersen, Klaus Ejner
1985-01-01
Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline...... with 30% (v/v) ethanol or saline, respectively. Relative viscosity was used as one measure of physical properties of the emulsion. Higher degrees of sensitization (but not rates) were obtained at the 48 h challenge reading with the oil/propylene glycol and oil/saline + ethanol emulsions compared...... to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions....
Maximal workload capacity on moving platforms
Heus, R.; Wertheim, A.H.
1996-01-01
Physical tasks on a moving platform required more energy than the same tasks on a non-moving platform. In this study the maximum aerobic performance (defined as V_O2max) of people working on a moving floor was established compared to the maximal aerobic performance on a non-moving floor. The main
Maximal workload capacity on moving platforms
Heus, R.; Wertheim, A.H.
1996-01-01
Physical tasks on a moving platform required more energy than the same tasks on a non-moving platform. In this study the maximum aerobic performance (defined as V_O2max) of people working on a moving floor was established compared to the maximal aerobic performance on a non-moving floor. The main qu
Trapp, C.
2014-01-01
Pre-combustion CO2 capture applied to integrated gasification combined cycle (IGCC) power plants is a promising technical solution to reduce CO2 emissions due to fossil-fuelled electricity generation in order to meet environmental targets in a carbon-constrained future. The pre-combustion capture
Trapp, C.
2014-01-01
Pre-combustion CO2 capture applied to integrated gasification combined cycle (IGCC) power plants is a promising technical solution to reduce CO2 emissions due to fossil-fuelled electricity generation in order to meet environmental targets in a carbon-constrained future. The pre-combustion capture pr
Farthing, G. A.; Rimpf, L. M.
2014-04-30
The overall goal of this project, as originally proposed, was to optimize the formulation of a novel solvent as a critical enabler for the cost-effective, energy-efficient, environmentally-friendly capture of CO{sub 2} at coal-fired utility plants. Aqueous blends of concentrated piperazine (PZ) with other compounds had been shown to exhibit high rates of CO{sub 2} absorption, low regeneration energy, and other desirable performance characteristics during an earlier 5-year development program conducted by B&W. The specific objective of this project was to identify PZ-based solvent formulations that globally optimize the performance of coal-fired power plants equipped with CO{sub 2} scrubbing systems. While previous solvent development studies have tended to focus on energy consumption and absorber size, important issues to be sure, the current work seeks to explore, understand, and optimize solvent formulation across the full gamut of issues related to commercial application of the technology: capital and operating costs, operability, reliability, environmental, health and safety (EH&S), etc. Work on the project was intended to be performed under four budget periods. The objective of the work in the first budget period has been to identify several candidate formulations of a concentrated PZ-based solvent for detailed characterization and evaluation. Work in the second budget period would generate reliable and comprehensive property and performance data for the identified formulations. Work in the third budget period would quantify the expected performance of the selected formulations in a commercial CO{sub 2} scrubbing process. Finally, work in the fourth budget period would provide a final technology feasibility study and a preliminary technology EH&S assessment. Due to other business priorities, however, B&W has requested that this project be terminated at the end of the first budget period. This document therefore serves as the final report for this project. It
Sums of magnetic eigenvalues are maximal on rotationally symmetric domains
Laugesen, Richard S; Roy, Arindam
2011-01-01
The sum of the first n energy levels of the planar Laplacian with constant magnetic field of given total flux is shown to be maximal among triangles for the equilateral triangle, under normalization of the ratio (moment of inertia)/(area)^3 on the domain. The result holds for both Dirichlet and Neumann boundary conditions, with an analogue for Robin (or de Gennes) boundary conditions too. The square similarly maximizes the eigenvalue sum among parallelograms, and the disk maximizes among ellipses. More generally, a domain with rotational symmetry will maximize the magnetic eigenvalue sum among all linear images of that domain. These results are new even for the ground state energy (n=1).
MAXIMS VIOLATIONS IN LITERARY WORK
Widya Hanum Sari Pertiwi
2015-12-01
Full Text Available This study was qualitative research action that focuses to find out the flouting of Gricean maxims and the functions of the flouting in the tales which are included in collection of children literature entitled My Giant Treasury of Stories and Rhymes. The objective of the study is generally to identify the violation of maxims of quantity, quality, relevance, and manner in the data sources and also to analyze the use of the flouting in the tales which are included in the book. Qualitative design using categorizing strategies, specifically coding strategy, was applied. Thus, the researcher as the instrument in this investigation was selecting the tales, reading them, and gathering every item which reflects the violation of Gricean maxims based on some conditions of flouting maxims. On the basis of the data analysis, it was found that the some utterances in the tales, both narration and conversation, flouting the four maxims of conversation, namely maxim of quality, maxim of quantity, maxim of relevance, and maxim of manner. The researcher has also found that the flouting of maxims has one basic function that is to encourage the readers’ imagination toward the tales. This one basic function is developed by six others functions: (1 generating specific situation, (2 developing the plot, (3 enlivening the characters’ utterance, (4 implicating message, (5 indirectly characterizing characters, and (6 creating ambiguous setting. Keywords: children literature, tales, flouting maxims
Methane capture from livestock manure.
Tauseef, S M; Premalatha, M; Abbasi, Tasneem; Abbasi, S A
2013-03-15
It has been estimated that livestock manure contributes about 240 million metric tons of carbon dioxide equivalent of methane to the atmosphere and represents one of the biggest anthropogenic sources of methane. Considering that methane is the second biggest contributor to global warming after carbon dioxide, it is imperative that ways and means are developed to capture as much of the anthropogenic methane as possible. There is a major associated advantage of methane capture: its use as a source of energy which is comparable in 'cleanness' to natural gas. The present review dwells upon the traditional ways of methane capture used in India, China, and other developing countries for providing energy to the rural poor. It then reviews the present status of methane capture from livestock manure in developed countries and touches upon the prevalent trends.
Swanepoel, Konrad J
2011-01-01
A subset of a normed space X is called equilateral if the distance between any two points is the same. Let m(X) be the smallest possible size of an equilateral subset of X maximal with respect to inclusion. We first observe that Petty's construction of a d-dimensional X of any finite dimension d >= 4 with m(X)=4 can be generalised to show that m(X\\oplus_1\\R)=4 for any X of dimension at least 2 which has a smooth point on its unit sphere. By a construction involving Hadamard matrices we then show that both m(\\ell_p) and m(\\ell_p^d) are finite and bounded above by a function of p, for all 1 1 such that m(X) <= d+1 for all d-dimensional X with Banach-Mazur distance less than c from \\ell_p^d. Using Brouwer's fixed-point theorem we show that m(X) <= d+1 for all d-\\dimensional X with Banach-Mazur distance less than 3/2 from \\ell_\\infty^d. A graph-theoretical argument furthermore shows that m(\\ell_\\infty^d)=d+1. The above results lead us to conjecture that m(X) <= 1+\\dim X.
Unified Maximally Natural Supersymmetry
Huang, Junwu
2016-01-01
Maximally Natural Supersymmetry, an unusual weak-scale supersymmetric extension of the Standard Model based upon the inherently higher-dimensional mechanism of Scherk-Schwarz supersymmetry breaking (SSSB), possesses remarkably good fine tuning given present LHC limits. Here we construct a version with precision $SU(2)_{\\rm L} \\times U(1)_{\\rm Y} $ unification: $\\sin^2 \\theta_W(M_Z) \\simeq 0.231$ is predicted to $\\pm 2\\%$ by unifying $SU(2)_{\\rm L} \\times U(1)_{\\rm Y} $ into a 5D $SU(3)_{\\rm EW}$ theory at a Kaluza-Klein scale of $1/R_5 \\sim 4.4\\,{\\rm TeV}$, where SSSB is simultaneously realised. Full unification with $SU(3)_{\\rm C}$ is accommodated by extending the 5D theory to a $N=4$ supersymmetric $SU(6)$ gauge theory on a 6D rectangular orbifold at $1/R_6 \\sim 40 \\,{\\rm TeV}$. TeV-scale states beyond the SM include exotic charged fermions implied by $SU(3)_{\\rm EW}$ with masses lighter than $\\sim 1.2\\,{\\rm TeV}$, and squarks in the mass range $1.4\\,{\\rm TeV} - 2.3\\,{\\rm TeV}$, providing distinct signature...
Alignment in double capture processes
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.
Dubovichenko, Sergey
2014-01-01
We have studied the neutron-capture reactions 10,11B(n, g) and the role of the 11B(n, g) reaction in seeding r-process nucleosynthesis. The possibility of the description of the available experimental data for cross sections of the neutron capture reaction on 10B at thermal and astrophysical energies, taking into account the resonance at 475 keV, was considered within the framework of the modified potential cluster model (MPCM) with forbidden states and accounting for the resonance behavior of the scattering phase shifts. In the framework of the same model the possibility of describing the available experimental data for the total cross sections of the neutron radiative capture on 11B at thermal and astrophysical energies were considered with taking into account the 21 and 430 keV resonances. Description of the available experimental data on the total cross sections and astrophysical S-factor of the radiative proton capture on 11B to the ground state of 12C was treated at astrophysical energies. The possibili...
Gosselin, A.; Husson, X.; Hennecart, D.; Hicham, S.; Kucal, H.; Lecler, D. [Caen Univ., 14 (France); Cassimi, A.; Grandin, J.P.; Jardin, P.; Lepoutre, A. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France)
1993-12-31
The Ar{sup 8+} ions are delivered by a recoil ion source (GANIL), the helium target consists in a supersonic jet. Three energy gain spectra were obtained for 400, 1600 and 2400 eV energy collision; each spectrum exhibits two peaks, the left one corresponds to an electron capture in the 5s level of Ar{sup 7+}, the right one corresponds to an electron capture in 4f and 4d levels. The difference between observed and expected energy position is due to the scattering angle which values allow for corrections and partial cross sections determination. Results are compared to the Landau-Zener calculation of Benmeuraien. 2 figs., 1 tab., 4 refs.
Baoyin, Hexi; CHEN Yang; Li, Junfeng
2011-01-01
Recently, Near Earth Objects (NEOs) have been attracting great attention, and thousands of NEOs have been found to date. This paper examines the NEOs' orbital dynamics using the framework of an accurate solar system model and a Sun-Earth-NEO three-body system when the NEOs are close to Earth to search for NEOs with low-energy orbits. It is possible for such an NEO to be temporarily captured by Earth; its orbit would thereby be changed and it would become an Earth-orbiting object after a small...
Hashimoto, Y; Hiraga, F; Kiyanagi, Y
2015-12-01
We evaluated the accelerator beam power and the neutron-induced radioactivity of (9)Be(p, n) boron neutron capture therapy (BNCT) neutron sources having a MgF2, CaF2, or AlF3 moderator and driven by protons with energy from 8 MeV to 30 MeV. The optimal moderator materials were found to be MgF2 for proton energies less than 10 MeV because of lower required accelerator beam power and CaF2 for higher proton energies because of lower photon dose rate at the treatment position after neutron irradiation.
Maximal subgroups of finite groups
S. Srinivasan
1990-01-01
Full Text Available In finite groups maximal subgroups play a very important role. Results in the literature show that if the maximal subgroup has a very small index in the whole group then it influences the structure of the group itself. In this paper we study the case when the index of the maximal subgroups of the groups have a special type of relation with the Fitting subgroup of the group.
Goncalez, O L
1998-01-01
Neutron photoproduction studies for sup 2 sup 3 sup 2 Th and sup 2 sup 3 sup 8 U were carried out from 5.6 to 10.8 MeV, using neutron capture gamma-rays with high resolution in energy (3 to 21 eV), produced by 30 target materials, placed inside a tangential beam port, near the core of the IPEN/CNEN-SP IEA-R1 2 MW research reactor. The samples (17.76 g of U sub 3 sub O sub 8 depleted to 0.349% in sup 2 sup 3 sup 5 U and 19.93 g of natural Th O sub 2) have been irradiated inside a 4 pi geometry neutron detector system sup L ong Counter sup , 520.5 cm away from the capture target. The capture gamma-ray flux was determined by means of the analysis of the gamma spectrum obtained by using a Ge(Li) solid-state detector (E G and G Ortec, 25 cm sup 3 , 5%), previously calibrated with capture gamma-rays from a standard target of Nitrogen (Melamine). The neutron photoproduction cross section has been measured for each target capture gamma-ray spectrum (compound cross section). A methodology for unfolding the set of expe...
Finding Maximal Quasiperiodicities in Strings
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...
Maximizing Entropy over Markov Processes
Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis
2013-01-01
computation reduces to finding a model of a specification with highest entropy. Entropy maximization for probabilistic process specifications has not been studied before, even though it is well known in Bayesian inference for discrete distributions. We give a characterization of global entropy of a process...... as a reward function, a polynomial algorithm to verify the existence of an system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...
Maximizing entropy over Markov processes
Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis
2014-01-01
computation reduces to finding a model of a specification with highest entropy. Entropy maximization for probabilistic process specifications has not been studied before, even though it is well known in Bayesian inference for discrete distributions. We give a characterization of global entropy of a process...... as a reward function, a polynomial algorithm to verify the existence of a system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...
Domínguez-Gutiérrez, F. J.; Cabrera-Trujillo, R.
2016-01-01
The electron capture process plays an important role as a diagnostic tool for measuring the temperature, plasma rotation, and impurity densities of plasma in tokamaks. In this work we report the electron capture and excitation cross-sections for Li+, Be{}2+, and {{{B}}}3+ colliding with atomic hydrogen in the collision energy range 0.25-25 keV/amu. For this, we solve numerically the time dependent Schrödinger equation by using a finite difference approach. We model the ion projectile interaction with the target using a pseudopotential obtained within a Hartree-Fock method. We use classical trajectories, obtained self-consistently, for the projectile at collision energies lower than 2 keV/amu and a straight line trajectory at high collision energies. We report new results for the total, n=2,3, and 4 state projectile electron capture cross-section, as well as the n = 2-state target excitation cross-section. We find a good agreement between our cross-section results when compared with available theoretical and experimental data found in the literature. Finally, we find that the electron capture probability, as a function of the impact parameter, shows Stückelberg oscillations at low collision energies for the n = 2 of Be+ and n = 3 of {{{B}}}2+, in the radial range (large impact parameters). Our results assess the validity of the adiabatic basis set at low collision energies and confirm the use of a finite difference method as an accurate approach to study a time-dependent process in charge exchange collisions. A discussion of our results is provided.
Maximum Wind Energy Capture Algorithm Based on Adaptive Variable Step Size%自适应变步长最大风能捕获算法
李树江; 蔡海锋; 邓金鹏; 孔丽新
2012-01-01
风能具有随机性、不稳定性的特点,为了提高风力发电系统中风能的利用效率,在比较各种最大风能捕获算法的基础上,分析了爬山搜索法和叶尖速比法的不足,提出了自适应变步长搜索算法来捕获最大风能.通过改进爬山搜索法的变步长策略,明显加快了搜索速度,通过引入初始估计叶尖速比值,大大缩小了搜索范围.该算法不需要实时检测准确风速,不依赖风力机最佳功率曲线,有效地降低了成本,提高风力发电的效率.文中重点分析了算法的自适应性和变步长策略,仿真结果表明,该算法能够使风力机更快速到达最大功率点,动态响应快,收敛性好.%Wind power has the characteristics of randomness and instability, to improve the using efficiency of the wind energy, the lack of HCS algorithm and TSR algorithm are analysed based on the comparison of different maximum algorithm, and an adaptive variable step search algorithm is proposed to capture the maximum wind power. The search speed is significantly accelerated by improving? Step size strategy of HCS, the search scope is greatly narrowed through the introduction of TSR of the initial estimates. Real-time detection speed isn' t required in this algorithm, which does not rely on the best wind turbine power curve, effectively reducing the cost and improve the efficiency of wind power. The adaptive and variable step size strategy of this algorithm is analysed in this paper, simulation results show that the algorithm can make wind turbines more quickly reach the maximum power point, fast dynamic response, good convergence.
Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj
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......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 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...
Gonzalez-Sanchez, Jon
2010-01-01
Let $w = w(x_1,..., x_n)$ be a word, i.e. an element of the free group $F =$ on $n$ generators $x_1,..., x_n$. The verbal subgroup $w(G)$ of a group $G$ is the subgroup generated by the set $\\{w (g_1,...,g_n)^{\\pm 1} | g_i \\in G, 1\\leq i\\leq n \\}$ of all $w$-values in $G$. We say that a (finite) group $G$ is $w$-maximal if $|G:w(G)|> |H:w(H)|$ for all proper subgroups $H$ of $G$ and that $G$ is hereditarily $w$-maximal if every subgroup of $G$ is $w$-maximal. In this text we study $w$-maximal and hereditarily $w$-maximal (finite) groups.
Maximizing without difficulty: A modified maximizing scale and its correlates
Lai, Linda
2010-01-01
... included in several previous studies. Based on this scale, maximizing is positively correlated with optimism, need for cognition, desire for consistency, risk aversion, intrinsic motivation, self-efficacy and perceived workload, whereas...
Maximizing and customer loyalty: Are maximizers less loyal?
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.
Are maximizers really unhappy? The measurement of maximizing tendency,
Dalia L. Diab
2008-06-01
Full Text Available Recent research suggesting that people who maximize are less happy than those who satisfice has received considerable fanfare. The current study investigates whether this conclusion reflects the construct itself or rather how it is measured. We developed an alternative measure of maximizing tendency that is theory-based, has good psychometric properties, and predicts behavioral outcomes. In contrast to the existing maximization measure, our new measure did not correlate with life (dissatisfaction, nor with most maladaptive personality and decision-making traits. We conclude that the interpretation of maximizers as unhappy may be due to poor measurement of the construct. We present a more reliable and valid measure for future researchers to use.
Principles of maximally classical and maximally realistic quantum mechanics
S M Roy
2002-08-01
Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2-dimensional phase space, a maximally realistic quantum mechanics can have quantum probabilities of no more than + 1 complete commuting cets (CCS) of observables coexisting as marginals of one positive phase space density. Here I formulate a stationary principle which gives a nonperturbative deﬁnition of a maximally classical as well as maximally realistic phase space density. I show that the maximally classical trajectories are in fact exactly classical in the simple examples of coherent states and bound states of an oscillator and Gaussian free particle states. In contrast, it is known that the de Broglie–Bohm realistic theory gives highly nonclassical trajectories.
吴忠强; 庄述燕; 韩延光
2013-01-01
针对风速多变及外界干扰情况下风电系统出现的风能利用率低、鲁棒性差及安全可靠性差等问题,提出了一种基于能量成形的直驱永磁风电系统最大风能捕获算法.该算法采用能量成形及端口受控哈密顿(PCH)系统方法,从能量平衡的角度,建立永磁发电机(PMSG) PCH系统的非线性模型,设计了PCH系统反馈控制器.通过基于PCH系统控制器和H∞控制器的叠加反馈,设计出能跟踪最佳转矩且具有扰动抑制的PCH系统H∞控制器.实验结果表明,该控制策略实现了风电系统的变速恒频运行、最大风能利用,验证了理论模型和控制策略的正确性、可行性.%Aiming at the problems of wind power system under variable wind speed and external disturbances, such as low wind energy utilization, poor robustness, low security and reliability, an algorithm is proposed based on energy shaping control method for direct-drive permanent-magnet wind power system to capture maximum wind power. The algorithm adopts energy shaping method and port-controlled Hamiltonian (PCH) system theory;and the PCH nonlinear model of permanent magnet synchronous generator (PMSG) is established from the energy-balancing point of view. The PCH feedback controller was designed. With the superposition feedback of PCH feedback controller and H∞ controller,a PCH system H∞ controller was designed to track optimal torque and suppress disturbance. The test result shows that this control strategy realizes variable speed constant frequency operation and maximum wind power utilization of wind power system,which verifies the validity and feasibility of theoretical model and control strategy.
10 CFR 63.312 - Required characteristics of the reasonably maximally exposed individual.
2010-01-01
... 10 Energy 2 2010-01-01 2010-01-01 false Required characteristics of the reasonably maximally exposed individual. 63.312 Section 63.312 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF... characteristics of the reasonably maximally exposed individual. The reasonably maximally exposed individual is...
Electron capture by bare ions on water molecules
Rivarola, Roberto; Montenegro, Pablo; Monti, Juan; Fojón, Omar
2016-05-01
Single electron capture from water molecules by impact of bare ions is theoretically investigated at intermediate and high collision energies. This reaction is of fundamental importance to determine the deposition of energy in biological matter irradiated with ion beams (hadrontherapy), dominating other ionizing processes of the target at low-intermediate impact velocities and giving principal contributions to the energetic region where electronic stopping power maximizes. The dynamics of the interaction between the aggregates is described within the one active-electron continuum distorted wave-eikonal initial state theory. The orbitals of the target in the ground state are represented using the approximate self-consistent complete neglect of differential orbitals (SC-CNDO) model. The contribution of different molecular orbitals on the partial cross sections to selected n-principal quantum number projectile states is discriminated as well as the collaboration of these n-states on total cross sections. The latter ones are dominated by capture to n=1 states at high enough energies decreasing their contribution as n increases.
Optimising the Target and Capture Sections of the Neutrino Factory
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 ...
Maximizing ROI with yield management
Neil Snyder
2001-01-01
.... the technology is based on the concept of yield management, which aims to sell the right product to the right customer at the right price and the right time therefore maximizing revenue, or yield...
Are CEOs Expected Utility Maximizers?
John List; Charles Mason
2009-01-01
Are individuals expected utility maximizers? This question represents much more than academic curiosity. In a normative sense, at stake are the fundamental underpinnings of the bulk of the last half-century's models of choice under uncertainty. From a positive perspective, the ubiquitous use of benefit-cost analysis across government agencies renders the expected utility maximization paradigm literally the only game in town. In this study, we advance the literature by exploring CEO's preferen...
All maximally entangling unitary operators
Cohen, Scott M. [Department of Physics, Duquesne University, Pittsburgh, Pennsylvania 15282 (United States); Department of Physics, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213 (United States)
2011-11-15
We characterize all maximally entangling bipartite unitary operators, acting on systems A and B of arbitrary finite dimensions d{sub A}{<=}d{sub B}, when ancillary systems are available to both parties. Several useful and interesting consequences of this characterization are discussed, including an understanding of why the entangling and disentangling capacities of a given (maximally entangling) unitary can differ and a proof that these capacities must be equal when d{sub A}=d{sub B}.
Salvio, Alberto; Strumia, Alessandro; Urbano, Alfredo
2016-01-01
Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal width into $\\gamma\\gamma$ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.
Capturing the Daylight Dividend
Peter Boyce; Claudia Hunter; Owen Howlett
2006-04-30
Capturing the Daylight Dividend conducted activities to build market demand for daylight as a means of improving indoor environmental quality, overcoming technological barriers to effective daylighting, and informing and assisting state and regional market transformation and resource acquisition program implementation efforts. The program clarified the benefits of daylight by examining whole building systems energy interactions between windows, lighting, heating, and air conditioning in daylit buildings, and daylighting's effect on the human circadian system and productivity. The project undertook work to advance photosensors, dimming systems, and ballasts, and provided technical training in specifying and operating daylighting controls in buildings. Future daylighting work is recommended in metric development, technology development, testing, training, education, and outreach.
Maximal temperature in a simple thermodynamical system
Dai, De-Chang
2016-01-01
Temperature in a simple thermodynamical system is not limited from above. It is also widely believed that it does not make sense talking about temperatures higher than the Planck temperature in the absence of the full theory of quantum gravity. Here, we demonstrate that there exist a maximal achievable temperature in a system where particles obey the laws of quantum mechanics and classical gravity before we reach the realm of quantum gravity. Namely, if two particles with a given center of mass energy come at the distance shorter than the Schwarzschild diameter apart, according to classical gravity they will form a black hole. It is possible to calculate that a simple thermodynamical system will be dominated by black holes at a critical temperature which is about three times lower than the Planck temperature. That represents the maximal achievable temperature in a simple thermodynamical system.
Swaminathan, Saravanan; Kuczynska, Agnieszka; Hume, Scott; Mulgundmath, Vinay; Freeman, Charles; Bearden, Mark; Remias, Joe; Ambedkar, Balraj; Salmon, Sonja; House, Alan
2012-11-01
The results of the preliminary techno-economic assessment for integrating a process utilizing low-energy solvents for carbon dioxide (CO2) capture enabled by a combination of enzymes and ultrasonics with a subcritical pulverized coal (PC) power plant are presented. Four cases utilizing the enzyme-activated solvent are compared using different methodologies of regeneration against the DOE/NETL reference MEA case. The results are shown comparing the energy demand for post-combustion CO2 capture and the net higher heating value (HHV) efficiency of the power plant integrated with the post-combustion capture (PCC) plant. A levelized cost of electricity (LCOE) assessment was performed showing the costs of the options presented in the study. The key factors contributing to the reduction of LCOE were identified as enzyme make-up rate and the capability of the ultrasonic regeneration process. The net efficiency of the integrated PC power plant with CO2 capture changes from 24.9% with the reference Case 10 plant to between 24.34% and 29.97% for the vacuum regeneration options considered, and to between 26.63% and 31.41% for the ultrasonic regeneration options. The evaluation also shows the effect of the critical parameters on the LCOE, with the main variable being the initial estimation of enzyme dosing rate. The LCOE ($/MWh) values range from 112.92 to 125.23 for the vacuum regeneration options and from 108.9 to 117.50 for the ultrasonic regeneration cases considered in comparison to 119.6 for the reference Case 10. A sensitivity analysis of the effect of critical parameters on the LCOE was also performed. The results from the preliminary techno-economic assessment show that the proposed technology can be investigated further with a view to being a viable alternative to conventional CO2 scrubbing technologies.
Dunbar, Laura
2014-01-01
This article is an introduction to video screen capture. Basic information of two software programs, QuickTime for Mac and BlueBerry Flashback Express for PC, are also discussed. Practical applications for video screen capture are given.
A. Garmroodi Asil
2017-09-01
To further reduce the sulfur dioxide emission of the entire refining process, two scenarios of acid gas or air preheats are investigated when either of them is used simultaneously with the third enrichment scheme. The maximum overall sulfur recovery efficiency and highest combustion chamber temperature is slightly higher for acid gas preheats but air preheat is more favorable because it is more benign. To the best of our knowledge, optimization of the entire GTU + enrichment section and SRU processes has not been addressed previously.
Mingrone, F.; Massimi, C.; Vannini, G.; Colonna, N.; Gunsing, F.; Žugec, P.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Domingo-Pardo, C.; Duran, I.; Dressler, R.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A. R.; Giubrone, G.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Hernández-Prieto, A.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Krtička, M.; Kroll, J.; Lampoudis, C.; Langer, C.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Leong, L. S.; Lo Meo, S.; Losito, R.; Mallick, A.; Manousos, A.; Marganiec, J.; Martínez, T.; Mastinu, P. F.; Mastromarco, M.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mirea, M.; Mondalaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Plompen, A.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego, A.; Robles, M. S.; Rubbia, C.; Sabaté-Gilarte, M.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J. L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Variale, V.; Vaz, P.; Ventura, A.; Vermeulen, M. J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T.; n TOF Collaboration
2017-03-01
The aim of this work is to provide a precise and accurate measurement of the 238U(n ,γ ) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behavior of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross section of 238U should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were proposed and carried out within the 7th Framework Project ANDES of the European Commission. The results of one of these 238U(n ,γ ) measurements performed at the n_TOF CERN facility are presented in this work. The γ -ray cascade following the radiative neutron capture has been detected exploiting a setup of two C6D6 liquid scintillators. Resonance parameters obtained from this work are on average in excellent agreement with the ones reported in evaluated libraries. In the unresolved resonance region, this work yields a cross section in agreement with evaluated libraries up to 80 keV, while for higher energies our results are significantly higher.
Algebraic curves of maximal cyclicity
Caubergh, Magdalena; Dumortier, Freddy
2006-01-01
The paper deals with analytic families of planar vector fields, studying methods to detect the cyclicity of a non-isolated closed orbit, i.e. the maximum number of limit cycles that can locally bifurcate from it. It is known that this multi-parameter problem can be reduced to a single-parameter one, in the sense that there exist analytic curves in parameter space along which the maximal cyclicity can be attained. In that case one speaks about a maximal cyclicity curve (mcc) in case only the number is considered and of a maximal multiplicity curve (mmc) in case the multiplicity is also taken into account. In view of obtaining efficient algorithms for detecting the cyclicity, we investigate whether such mcc or mmc can be algebraic or even linear depending on certain general properties of the families or of their associated Bautin ideal. In any case by well chosen examples we show that prudence is appropriate.
BOUNDEDNESS OF MAXIMAL SINGULAR INTEGRALS
CHEN JIECHENG; ZHU XIANGRONG
2005-01-01
The authors study the singular integrals under the Hormander condition and the measure not satisfying the doubling condition. At first, if the corresponding singular integral is bounded from L2 to itseff, it is proved that the maximal singu lar integral is bounded from L∞ to RBMO except that it is infinite μ-a.e. on Rd. A sufficient condition and a necessary condition such that the maximal singular integral is bounded from L2 to itself are also obtained. There is a small gap between the two conditions.
Harput, Sevan; Cowell, David M J; Freear, Steven
2016-01-01
The importance of the excitation bandwidth is well known in diagnostic ultrasound imaging. However, the effect of excitation bandwidth in therapeutic applications of microbubbles has been mostly overlooked. A majority of contrast agent production techniques generate polydisperse microbubble populations, so a wide range of resonance frequencies exist. Therefore, wideband excitation is necessary to fully utilize microbubble resonance behavior and maximize the reradiated energy from a microbubble population, both for imaging and therapy. Oscillations of sixty SonoVue microbubbles in proximity of a rigid boundary were captured on a high speed camera at 3 Mfps, excited with a peak negative pressure of 50 kPa at 1 MHz. Measurements were analyzed according to their peak radiated pressure, radial oscillations, root mean squared pressure, and shear stress generated by microbubbles. Results showed that long duration and wideband excitation at low intensity levels was preferable for sonoporation, where microbubbles can ...
Understanding maximal repetitions in strings
Crochemore, Maxime
2008-01-01
The cornerstone of any algorithm computing all repetitions in a string of length n in O(n) time is the fact that the number of runs (or maximal repetitions) is O(n). We give a simple proof of this result. As a consequence of our approach, the stronger result concerning the linearity of the sum of exponents of all runs follows easily.
Mingrone, F.
2017-01-01
The aim of this work is to provide a precise and accurate measurement of the 238U(n,g) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behaviour of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross-section of 238U should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were proposed and carrie...
Mingrone, F; Vannini, G; Colonna, N; Gunsing, F; Zugec, P; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Becares, V; Becvavr, F; Belloni, F; Berthoumieux, E; Billowes, J; Bosnar, D; Brugger, M; Calviani, M; Calvino, F; Cano-Ott, D; Carrapico, C; Cerutti, F; Chiaveri, E; Chin, M; Cortes, G; Cortes-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; Garcia, A R; Giubrone, G; Goncalves, I F; Gonzalez-Romero, E; Griesmayer, E; Guerrero, C; Hernandez-Prieto, A; Jenkins, D G; Jericha, E; Kadi, Y; Kappeler, F; Karadimos, D; Kivel, N; Koehler, P; Kokkoris, M; Krticka, M; Kroll, J; Lampoudis, C; Langer, C; Leal-Cidoncha, E; Lederer, C; Leeb, H; Leong, L S; Lo Meo, S; Losito, R; Mallick, A; Manousos, A; Marganiec, J; Martinez, T; Mastinu, P F; Mastromarco, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mirea Horia, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Robles, M S; Rubbia, C; Sabate-Gilarte, M; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; LTain, J; Tarrio, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Variale, V; Vaz, P; Ventura, A; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiss, C; Wright, T
2016-01-01
The aim of this work is to provide a precise and accurate measurement of the $^{238}$U(n,$\\gamma$) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behaviour of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross-section of $^{238}$U should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were pr...
Neutron Capture Nucleosynthesis
Kiss, Miklos
2016-01-01
Heavy elements (beyond iron) are formed in neutron capture nucleosynthesis processes. We have proposed a simple unified model to investigate the neutron capture nucleosynthesis in arbitrary neutron density environment. We have also investigated what neutron density is required to reproduce the measured abundance of nuclei assuming equilibrium processes. We found both of these that the medium neutron density has a particularly important role at neutron capture nucleosynthesis. About these results most of the nuclei can formed at medium neutron capture density environment e.g. in some kind of AGB stars. Besides these observations our model is capable to use educational purpose.
Note on maximal distance separable codes
YANG Jian-sheng; WANG De-xiu; JIN Qing-fang
2009-01-01
In this paper, the maximal length of maximal distance separable(MDS)codes is studied, and a new upper bound formula of the maximal length of MDS codes is obtained. Especially, the exact values of the maximal length of MDS codes in some parameters are given.
Neutron capture cross section and capture gamma-ray spectra of 89Y
Katabuchi Tatsuya
2016-01-01
Full Text Available The neutron capture cross section of 89Y was measured by the time-of-flight method in an energy range from 15 to 100 keV. A pulse-height weighting technique was applied to derive the capture yield. The absolute cross section was determined based on the standard reaciotn 197 Au(n, γ198 Au reaction. The neutron capture γ-ray spectrum was derived by unfolding the pulse-height spectrum with detector response functions.
Minchener, A.
2007-07-15
There are a large number of ways in which the capture of carbon as carbon dioxide (CO{sub 2}) can be integrated into fossil fuel power stations, most being applicable for both gas and coal feedstocks. To add to the choice of technology is the question of whether an existing plant should be retrofitted for capture, or whether it is more attractive to build totally new. This miscellany of choices adds considerably to the commercial risk of investing in a large power station. An intermediate stage between the non-capture and full capture state would be advantageous in helping to determine the best way forward and hence reduce those risks. In recent years the term 'carbon capture ready' or 'capture ready' has been coined to describe such an intermediate stage plant and is now widely used. However a detailed and all-encompassing definition of this term has never been published. All fossil fuel consuming plant produce a carbon dioxide gas byproduct. There is a possibility of scrubbing it with an appropriate CO{sub 2} solvent. Hence it could be said that all fossil fuel plant is in a condition for removal of its CO{sub 2} effluent and therefore already in a 'capture ready' state. Evidently, the practical reality of solvent scrubbing could cost more than the rewards offered by such as the ETS (European Trading Scheme). In which case, it can be said that although the possibility exists of capturing CO{sub 2}, it is not a commercially viable option and therefore the plant could not be described as ready for CO{sub 2} capture. The boundary between a capture ready and a non-capture ready condition using this definition cannot be determined in an objective and therefore universally acceptable way and criteria must be found which are less onerous and less potentially contentious to assess. 16 refs., 2 annexes.
Optimal bounded control for maximizing reliability of Duhem hysteretic systems
Ming XU; Xiaoling JIN; Yong WANG; Zhilong HUANG
2015-01-01
The optimal bounded control of stochastic-excited systems with Duhem hysteretic components for maximizing system reliability is investigated. The Duhem hysteretic force is transformed to energy-depending damping and stiffness by the energy dissipation balance technique. The controlled system is transformed to the equivalent non-hysteretic system. Stochastic averaging is then implemented to obtain the Itˆo stochastic equation associated with the total energy of the vibrating system, appropriate for eval-uating system responses. Dynamical programming equations for maximizing system re-liability are formulated by the dynamical programming principle. The optimal bounded control is derived from the maximization condition in the dynamical programming equa-tion. Finally, the conditional reliability function and mean time of first-passage failure of the optimal Duhem systems are numerically solved from the Kolmogorov equations. The proposed procedure is illustrated with a representative example.
Synchronous generator wind energy conversion control system
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.
CAPTURED India Country Evaluation
O'Donoghue, R.; Brouwers, J.H.A.M.
2012-01-01
This report provides the findings of the India Country Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the End Evaluation has assessed that results are commendable. I-AIM was able to design an approach in which health fol
Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.
2012-01-01
Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2
Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.
2012-01-01
Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2
CAPTURED India Country Evaluation
O'Donoghue, R.; Brouwers, J.H.A.M.
2012-01-01
This report provides the findings of the India Country Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the End Evaluation has assessed that results are commendable. I-AIM was able to design an approach in which health
Uddin, M.S. [Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Savar, GPO Box No. 3787, Dhaka-1000 (Bangladesh)], E-mail: shuza88@yahoo.co.in; Chowdhury, M.H. [Department of Physics, Comilla Victoria Government College, Comilla (Bangladesh); Department of Physics, Jahangirnagar University, Savar, Dhaka (Bangladesh); Hossain, S.M.; Latif, Sk.A.; Hafiz, M.A.; Islam, M.A.; Zakaria, A.K.M. [Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Savar, GPO Box No. 3787, Dhaka-1000 (Bangladesh); Azharul Islam, S.M. [Department of Physics, Jahangirnagar University, Savar, Dhaka (Bangladesh)
2008-09-15
The thermal neutron-induced activation cross section for the {sup 186}W(n,{gamma}){sup 187}W reaction was measured at 0.0536 eV neutron energy using TRIGA Mark-II research reactor, Atomic Energy Research Establishment, Savar, Dhaka, Bangladesh. The {sup 197}Au(n,{gamma}){sup 198}Au monitor reaction induced in a high-purity gold foil was used to determine the effective neutron beam intensity. The activities induced in sample and monitor foils were measured nondestructively by a high-resolution HPGe {gamma}-ray detector. The present experimental cross-section value is the first one at 0.0536 eV. The obtained new cross section that amounts to 26.6{+-}1.6 b is 2% higher than the recently reported data in ENDF/B-VII and 5% lower than that of JENDL-3.3.
Xia Yi Jun; Yang Zhi Hua
2001-01-01
The cross sections for the sup 1 sup 7 sup 4 Hf( n, gamma) sup 1 sup 7 sup 5 Hf reaction were measured relatively to the sup 1 sup 9 sup 7 Au(n, gamma) sup 1 sup 9 sup 8 Au reaction for neutron energies from 162 to 1200 keV, using the activation technique with high resolution HPGE gamma ray spectroscopy. Some experimental data were given for the first time
Langhout, Rob; Weber, Marvin; Tak, Igor; Lenssen, Ton
2016-01-01
The first aim of this study was to describe duration and relative timing of the phases of the maximal instep kick. The second aim was to describe the concurrence of maximal range of motion, maximal angular acceleration, maximal angular deceleration and maximal angular velocity of body segments with four key points. Twenty experienced football players performed three maximal instep kicks. The kicks were analysed using a full body, three-dimensional motion capture system. Camera recordings determined kicking leg events. The concurrence of peak kinematics of body segments with four key points was calculated. Duration and timing of five phases were identified. Key point maximal hip extension (51.4±5.0%) concurred significantly with maximal range of motion (ROM) of shoulder extension. Key point maximal knee flexion (63.6±5.2%) concurred significantly with maximal angular acceleration of spine flexion and pelvis posterior tilt. Key point knee flexion 90 degrees (69.3±4.9%) concurred significantly with maximal angular velocity of shoulder flexion and spine flexion, maximal angular deceleration of hip flexion and maximal angular acceleration of knee extension. Key point ball impact (75.2±5.2%) concurred significantly with maximal ROM of hip deflexion and pelvis anterior rotation and with maximal angular deceleration of spine flexion and pelvis anterior rotation. This study demonstrated that eleven peak kinematics of upper body and kicking leg segments, significantly concurred with four kicking leg positions. These results provide Key points for kicking coordination and stress the importance of dynamical coupling as a kicking mechanism.
Tondeur, D
2005-07-01
In the framework of the global warming resulting of the greenhouse gases emission increase, the carbon dioxide capture and storage in deep underground cavities of old petroleum and gas deposits, are studied. This report presents the researches realized by the CNRS (France) in the domain: technology and knowledge assessment concerning the carbon dioxide capture and storage, active coals for the CO{sub 2} capture, methodology of thermo-economical optimization of the combined cycle, global simulation of an IGCC (Integrated gasification combined cycle) with CO{sub 2} capture and integration in the process scheme, petroleum recovery-aided by CO{sub 2} injection, storage in geological deposits. (A.L.B.)
Encapsulated liquid sorbents for carbon dioxide capture.
Vericella, John J; Baker, Sarah E; Stolaroff, Joshuah K; Duoss, Eric B; Hardin, James O; Lewicki, James; Glogowski, Elizabeth; Floyd, William C; Valdez, Carlos A; Smith, William L; Satcher, Joe H; Bourcier, William L; Spadaccini, Christopher M; Lewis, Jennifer A; Aines, Roger D
2015-02-05
Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.
Pascale, J. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche sur l`Etat Condense, les Atomes et les Molecules; Jacquet, E. [Caen Univ., 14 (France). Lab. de Spectroscopie Atomique
1994-12-31
The effect of the electronic core of the projectile ion on the single capture electron n1 final states during collisions between X{sup 8+} ions (X= Ne, Ar, Kr) and Li(2s). Experimental cross sections are obtained from X{sup 7+} emission line measurements and are compared to calculations using the Monte Carlo type classical trajectory method. 3 figs., 6 refs.
Asymptotics of robust utility maximization
Knispel, Thomas
2012-01-01
For a stochastic factor model we maximize the long-term growth rate of robust expected power utility with parameter $\\lambda\\in(0,1)$. Using duality methods the problem is reformulated as an infinite time horizon, risk-sensitive control problem. Our results characterize the optimal growth rate, an optimal long-term trading strategy and an asymptotic worst-case model in terms of an ergodic Bellman equation. With these results we propose a duality approach to a "robust large deviations" criterion for optimal long-term investment.
Multivariate residues and maximal unitarity
Søgaard, Mads; Zhang, Yang
2013-12-01
We extend the maximal unitarity method to amplitude contributions whose cuts define multidimensional algebraic varieties. The technique is valid to all orders and is explicitly demonstrated at three loops in gauge theories with any number of fermions and scalars in the adjoint representation. Deca-cuts realized by replacement of real slice integration contours by higher-dimensional tori encircling the global poles are used to factorize the planar triple box onto a product of trees. We apply computational algebraic geometry and multivariate complex analysis to derive unique projectors for all master integral coefficients and obtain compact analytic formulae in terms of tree-level data.
Beeping a Maximal Independent Set
Afek, Yehuda; Alon, Noga; Bar-Joseph, Ziv; Cornejo, Alejandro; Haeupler, Bernhard; Kuhn, Fabian
2012-01-01
We consider the problem of computing a maximal independent set (MIS) in an extremely harsh broadcast model that relies only on carrier sensing. The model consists of an anonymous broadcast network in which nodes have no knowledge about the topology of the network or even an upper bound on its size. Furthermore, it is assumed that an adversary chooses at which time slot each node wakes up. At each time slot a node can either beep, that is, emit a signal, or be silent. At a particular time slot...
Maximal Congruences on Some Semigroups
Jintana Sanwong; R.P. Sullivan
2007-01-01
In 1976 Howie proved that a finite congruence-free semigroup is a simple group if it has at least three elements but no zero elementInfinite congruence-free semigroups are far more complicated to describe, but some have been constructed using semigroups of transformations (for example, by Howie in 1981 and by Marques in 1983)Here, forcertain semigroups S of numbers and of transformations, we determine all congruences p on S such that S/p is congruence-free, that is, we describe all maximal congruences on such semigroups S.
Selective particle capture by asynchronously beating cilia
Ding, Yang; Kanso, Eva
2015-12-01
Selective particle filtration is fundamental in many engineering and biological systems. For example, many aquatic microorganisms use filter feeding to capture food particles from the surrounding fluid, using motile cilia. One of the capture strategies is to use the same cilia to generate feeding currents and to intercept particles when the particles are on the downstream side of the cilia. Here, we develop a 3D computational model of ciliary bands interacting with flow suspended particles and calculate particle trajectories for a range of particle sizes. Consistent with experimental observations, we find optimal particle sizes that maximize capture rate. The optimal size depends nonlinearly on cilia spacing and cilia coordination, synchronous vs. asynchronous. These parameters affect the cilia-generated flow field, which in turn affects particle trajectories. The low capture rate of smaller particles is due to the particles' inability to cross the flow streamlines of neighboring cilia. Meanwhile, large particles have difficulty entering the sub-ciliary region once advected downstream, also resulting in low capture rates. The optimal range of particle sizes is enhanced when cilia beat asynchronously. These findings have potentially important implications on the design and use of biomimetic cilia in processes such as particle sorting in microfluidic devices.
Knowledge discovery by accuracy maximization.
Cacciatore, Stefano; Luchinat, Claudio; Tenori, Leonardo
2014-04-01
Here we describe KODAMA (knowledge discovery by accuracy maximization), an unsupervised and semisupervised learning algorithm that performs feature extraction from noisy and high-dimensional data. Unlike other data mining methods, the peculiarity of KODAMA is that it is driven by an integrated procedure of cross-validation of the results. The discovery of a local manifold's topology is led by a classifier through a Monte Carlo procedure of maximization of cross-validated predictive accuracy. Briefly, our approach differs from previous methods in that it has an integrated procedure of validation of the results. In this way, the method ensures the highest robustness of the obtained solution. This robustness is demonstrated on experimental datasets of gene expression and metabolomics, where KODAMA compares favorably with other existing feature extraction methods. KODAMA is then applied to an astronomical dataset, revealing unexpected features. Interesting and not easily predictable features are also found in the analysis of the State of the Union speeches by American presidents: KODAMA reveals an abrupt linguistic transition sharply separating all post-Reagan from all pre-Reagan speeches. The transition occurs during Reagan's presidency and not from its beginning.
Inapproximability of maximal strip recovery
Jiang, Minghui
2009-01-01
In comparative genomic, the first step of sequence analysis is usually to decompose two or more genomes into syntenic blocks that are segments of homologous chromosomes. For the reliable recovery of syntenic blocks, noise and ambiguities in the genomic maps need to be removed first. Maximal Strip Recovery (MSR) is an optimization problem proposed by Zheng, Zhu, and Sankoff for reliably recovering syntenic blocks from genomic maps in the midst of noise and ambiguities. Given $d$ genomic maps as sequences of gene markers, the objective of \\msr{d} is to find $d$ subsequences, one subsequence of each genomic map, such that the total length of syntenic blocks in these subsequences is maximized. For any constant $d \\ge 2$, a polynomial-time 2d-approximation for \\msr{d} was previously known. In this paper, we show that for any $d \\ge 2$, \\msr{d} is APX-hard, even for the most basic version of the problem in which all gene markers are distinct and appear in positive orientation in each genomic map. Moreover, we provi...
Maximal right smooth extension chains
Huang, Yun Bao
2010-01-01
If $w=u\\alpha$ for $\\alpha\\in \\Sigma=\\{1,2\\}$ and $u\\in \\Sigma^*$, then $w$ is said to be a \\textit{simple right extension}of $u$ and denoted by $u\\prec w$. Let $k$ be a positive integer and $P^k(\\epsilon)$ denote the set of all $C^\\infty$-words of height $k$. Set $u_{1},\\,u_{2},..., u_{m}\\in P^{k}(\\epsilon)$, if $u_{1}\\prec u_{2}\\prec ...\\prec u_{m}$ and there is no element $v$ of $P^{k}(\\epsilon)$ such that $v\\prec u_{1}\\text{or} u_{m}\\prec v$, then $u_{1}\\prec u_{2}\\prec...\\prec u_{m}$ is said to be a \\textit{maximal right smooth extension (MRSE) chains}of height $k$. In this paper, we show that \\textit{MRSE} chains of height $k$ constitutes a partition of smooth words of height $k$ and give the formula of the number of \\textit{MRSE} chains of height $k$ for each positive integer $k$. Moreover, since there exist the minimal height $h_1$ and maximal height $h_2$ of smooth words of length $n$ for each positive integer $n$, we find that \\textit{MRSE} chains of heights $h_1-1$ and $h_2+1$ are good candidates t...
National Oceanic and Atmospheric Administration, Department of Commerce — To estimate abundance, growth, and survival rate and to collect tissue samples, marine turtles are captured at nesting beaches and foraging grounds through various...
Daniel P. Schrag
2007-01-01
.... Scientific and economic challenges still exist, but none are serious enough to suggest that carbon capture and storage will not work at the scale required to offset trillions of tons of carbon...
Statistical mechanics of influence maximization with thermal noise
Lynn, Christopher W.; Lee, Daniel D.
2017-03-01
The problem of optimally distributing a budget of influence among individuals in a social network, known as influence maximization, has typically been studied in the context of contagion models and deterministic processes, which fail to capture stochastic interactions inherent in real-world settings. Here, we show that by introducing thermal noise into influence models, the dynamics exactly resemble spins in a heterogeneous Ising system. In this way, influence maximization in the presence of thermal noise has a natural physical interpretation as maximizing the magnetization of an Ising system given a budget of external magnetic field. Using this statistical mechanical formulation, we demonstrate analytically that for small external-field budgets, the optimal influence solutions exhibit a highly non-trivial temperature dependence, focusing on high-degree hub nodes at high temperatures and on easily influenced peripheral nodes at low temperatures. For the general problem, we present a projected gradient ascent algorithm that uses the magnetic susceptibility to calculate locally optimal external-field distributions. We apply our algorithm to synthetic and real-world networks, demonstrating that our analytic results generalize qualitatively. Our work establishes a fruitful connection with statistical mechanics and demonstrates that influence maximization depends crucially on the temperature of the system, a fact that has not been appreciated by existing research.
D2-brane Chern-Simons theories: F-maximization = a-maximization
Fluder, Martin
2015-01-01
We study a system of N D2-branes probing a generic Calabi-Yau three-fold singularity in the presence of a non-zero quantized Romans mass n. We argue that the low-energy effective N = 2 Chern-Simons quiver gauge theory flows to a superconformal fixed point in the IR, and construct the dual AdS_4 solution in massive IIA supergravity. We compute the free energy F of the gauge theory on S^3 using localization. In the large N limit we find F = c(nN)^{1/3}a^{2/3}, where c is a universal constant and a is the a-function of the "parent" four-dimensional N = 1 theory on N D3-branes probing the same Calabi-Yau singularity. It follows that maximizing F over the space of admissible R-symmetries is equivalent to maximizing a for this class of theories. Moreover, we show that the gauge theory result precisely matches the holographic free energy of the supergravity solution, and provide a similar matching of the VEV of a BPS Wilson loop operator.
The maximal D = 4 supergravities
Wit, Bernard de [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, Postbus 80.195, NL-3508 TD Utrecht (Netherlands); Samtleben, Henning [Laboratoire de Physique, ENS Lyon, 46 allee d' Italie, F-69364 Lyon CEDEX 07 (France); Trigiante, Mario [Dept. of Physics, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy)
2007-06-15
All maximal supergravities in four space-time dimensions are presented. The ungauged Lagrangians can be encoded in an E{sub 7(7)}-Sp(56; R)/GL(28) matrix associated with the freedom of performing electric/magnetic duality transformations. The gauging is defined in terms of an embedding tensor {theta} which encodes the subgroup of E{sub 7(7)} that is realized as a local invariance. This embedding tensor may imply the presence of magnetic charges which require corresponding dual gauge fields. The latter can be incorporated by using a recently proposed formulation that involves tensor gauge fields in the adjoint representation of E{sub 7(7)}. In this formulation the results take a universal form irrespective of the electric/magnetic duality basis. We present the general class of supersymmetric and gauge invariant Lagrangians and discuss a number of applications.
Maximizing profit using recommender systems
Das, Aparna; Ricketts, Daniel
2009-01-01
Traditional recommendation systems make recommendations based solely on the customer's past purchases, product ratings and demographic data without considering the profitability the items being recommended. In this work we study the question of how a vendor can directly incorporate the profitability of items into its recommender so as to maximize its expected profit while still providing accurate recommendations. Our approach uses the output of any traditional recommender system and adjust them according to item profitabilities. Our approach is parameterized so the vendor can control how much the recommendation incorporating profits can deviate from the traditional recommendation. We study our approach under two settings and show that it achieves approximately 22% more profit than traditional recommendations.
The maximal D=5 supergravities
de Wit, Bernard; Trigiante, M; Wit, Bernard de; Samtleben, Henning; Trigiante, Mario
2007-01-01
The general Lagrangian for maximal supergravity in five spacetime dimensions is presented with vector potentials in the \\bar{27} and tensor fields in the 27 representation of E_6. This novel tensor-vector system is subject to an intricate set of gauge transformations, describing 3(27-t) massless helicity degrees of freedom for the vector fields and 3t massive spin degrees of freedom for the tensor fields, where the (even) value of t depends on the gauging. The kinetic term of the tensor fields is accompanied by a unique Chern-Simons coupling which involves both vector and tensor fields. The Lagrangians are completely encoded in terms of the embedding tensor which defines the E_6 subgroup that is gauged by the vectors. The embedding tensor is subject to two constraints which ensure the consistency of the combined vector-tensor gauge transformations and the supersymmetry of the full Lagrangian. This new formulation encompasses all possible gaugings.
Constraint Propagation as Information Maximization
Abdallah, A Nait
2012-01-01
Dana Scott used the partial order among partial functions for his mathematical model of recursively defined functions. He interpreted the partial order as one of information content. In this paper we elaborate on Scott's suggestion of regarding computation as a process of information maximization by applying it to the solution of constraint satisfaction problems. Here the method of constraint propagation can be interpreted as decreasing uncertainty about the solution -- that is, as gain in information about the solution. As illustrative example we choose numerical constraint satisfaction problems to be solved by interval constraints. To facilitate this approach to constraint solving we formulate constraint satisfaction problems as formulas in predicate logic. This necessitates extending the usual semantics for predicate logic so that meaning is assigned not only to sentences but also to formulas with free variables.
Uddin, M.S. [Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Savar, GPO Box No. 3787, Dhaka 1000 (Bangladesh)], E-mail: shuza88@yahoo.co.in; Chowdhury, M.H. [Department of Physics, Comilla Victoria Government College, Comilla (Bangladesh); Department of Physics, Jahangirnagar University, Savar, Dhaka (Bangladesh); Hossain, S.M.; Latif, Sk.A.; Islam, M.A.; Hafiz, M.A.; Mubin, S.H.; Zakaria, A.K.M.; Yunus, S.M. [Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Savar, GPO Box No. 3787, Dhaka 1000 (Bangladesh); Azharul Islam, S.M. [Department of Physics, Jahangirnagar University, Savar, Dhaka (Bangladesh)
2008-11-15
The neutron capture cross sections for the {sup 152}Sm(n,{gamma}){sup 153}Sm and {sup 154}Sm(n,{gamma}){sup 155}Sm reactions at 0.0536 eV neutron energy were measured using an activation technique based on the TRIGA Mark-II research reactor, relative to the reference reaction {sup 197}Au(n,{gamma}){sup 198}Au. The activity was measured nondestructively using gamma-ray spectroscopy. Our measured values at this neutron energy are the first ones and are compared with 1/v based evaluated cross sections reported in the ENDF/B-VII and JENDL-3.3 libraries. The measured value for the {sup 152}Sm(n,{gamma}){sup 153}Sm reaction is 0.28% lower than JENDL-3.3 and 0.48% higher than ENDF/B-VII. Our value for the production of {sup 155}Sm is about 3% and 2.3% higher than the evaluated value with ENDF/B-VII and JENDL-3.3 at 0.0536 eV, respectively.
Iodine neutron capture therapy
Ahmed, Kazi Fariduddin
A new technique, Iodine Neutron Capture Therapy (INCT) is proposed to treat hyperthyroidism in people. Present thyroid therapies, surgical removal and 131I treatment, result in hypothyroidism and, for 131I, involve protracted treatment times and excessive whole-body radiation doses. The new technique involves using a low energy neutron beam to convert a fraction of the natural iodine stored in the thyroid to radioactive 128I, which has a 24-minute half-life and decays by emitting 2.12-MeV beta particles. The beta particles are absorbed in and damage some thyroid tissue cells and consequently reduce the production and release of thyroid hormones to the blood stream. Treatment times and whole-body radiation doses are thus reduced substantially. This dissertation addresses the first of the several steps needed to obtain medical profession acceptance and regulatory approval to implement this therapy. As with other such programs, initial feasibility is established by performing experiments on suitable small mammals. Laboratory rats were used and their thyroids were exposed to the beta particles coming from small encapsulated amounts of 128I. Masses of 89.0 mg reagent-grade elemental iodine crystals have been activated in the ISU AGN-201 reactor to provide 0.033 mBq of 128I. This activity delivers 0.2 Gy to the thyroid gland of 300-g male rats having fresh thyroid tissue masses of ˜20 mg. Larger iodine masses are used to provide greater doses. The activated iodine is encapsulated to form a thin (0.16 cm 2/mg) patch that is then applied directly to the surgically exposed thyroid of an anesthetized rat. Direct neutron irradiation of a rat's thyroid was not possible due to its small size. Direct in-vivo exposure of the thyroid of the rat to the emitted radiation from 128I is allowed to continue for 2.5 hours (6 half-lives). Pre- and post-exposure blood samples are taken to quantify thyroid hormone levels. The serum T4 concentration is measured by radioimmunoassay at
US Spacesuit Knowledge Capture
Chullen, Cinda; Thomas, Ken; McMann, Joe; Dolan, Kristi; Bitterly, Rose; Lewis, Cathleen
2011-01-01
The ability to learn from both the mistakes and successes of the past is vital to assuring success in the future. Due to the close physical interaction between spacesuit systems and human beings as users, spacesuit technology and usage lends itself rather uniquely to the benefits realized from the skillful organization of historical information; its dissemination; the collection and identification of artifacts; and the education of those in the field. The National Aeronautics and Space Administration (NASA), other organizations and individuals have been performing United States (U.S.) Spacesuit Knowledge Capture since the beginning of space exploration. Avenues used to capture the knowledge have included publication of reports; conference presentations; specialized seminars; and classes usually given by veterans in the field. More recently the effort has been more concentrated and formalized whereby a new avenue of spacesuit knowledge capture has been added to the archives in which videotaping occurs engaging both current and retired specialists in the field presenting technical scope specifically for education and preservation of knowledge. With video archiving, all these avenues of learning can now be brought to life with the real experts presenting their wealth of knowledge on screen for future learners to enjoy. Scope and topics of U.S. spacesuit knowledge capture have included lessons learned in spacesuit technology, experience from the Gemini, Apollo, Skylab and Shuttle programs, hardware certification, design, development and other program components, spacesuit evolution and experience, failure analysis and resolution, and aspects of program management. Concurrently, U.S. spacesuit knowledge capture activities have progressed to a level where NASA, the National Air and Space Museum (NASM), Hamilton Sundstrand (HS) and the spacesuit community are now working together to provide a comprehensive closed-looped spacesuit knowledge capture system which includes
Beeping a Maximal Independent Set
Afek, Yehuda; Bar-Joseph, Ziv; Cornejo, Alejandro; Haeupler, Bernhard; Kuhn, Fabian
2012-01-01
We consider the problem of computing a maximal independent set (MIS) in an extremely harsh broadcast model that relies only on carrier sensing. The model consists of an anonymous broadcast network in which nodes have no knowledge about the topology of the network or even an upper bound on its size. Furthermore, it is assumed that an adversary chooses at which time slot each node wakes up. At each time slot a node can either beep, that is, emit a signal, or be silent. At a particular time slot, beeping nodes receive no feedback, while silent nodes can only differentiate between none of its neighbors beeping, or at least one of its neighbors beeping. We start by proving a lower bound that shows that in this model, it is not possible to locally converge to an MIS in sub-polynomial time. We then study four different relaxations of the model which allow us to circumvent the lower bound and find an MIS in polylogarithmic time. First, we show that if a polynomial upper bound on the network size is known, it is possi...
Maximal switchability of centralized networks
Vakulenko, Sergei; Morozov, Ivan; Radulescu, Ovidiu
2016-08-01
We consider continuous time Hopfield-like recurrent networks as dynamical models for gene regulation and neural networks. We are interested in networks that contain n high-degree nodes preferably connected to a large number of N s weakly connected satellites, a property that we call n/N s -centrality. If the hub dynamics is slow, we obtain that the large time network dynamics is completely defined by the hub dynamics. Moreover, such networks are maximally flexible and switchable, in the sense that they can switch from a globally attractive rest state to any structurally stable dynamics when the response time of a special controller hub is changed. In particular, we show that a decrease of the controller hub response time can lead to a sharp variation in the network attractor structure: we can obtain a set of new local attractors, whose number can increase exponentially with N, the total number of nodes of the nework. These new attractors can be periodic or even chaotic. We provide an algorithm, which allows us to design networks with the desired switching properties, or to learn them from time series, by adjusting the interactions between hubs and satellites. Such switchable networks could be used as models for context dependent adaptation in functional genetics or as models for cognitive functions in neuroscience.
A Maximally Supersymmetric Kondo Model
Harrison, Sarah; Kachru, Shamit; Torroba, Gonzalo; /Stanford U., Phys. Dept. /SLAC
2012-02-17
We study the maximally supersymmetric Kondo model obtained by adding a fermionic impurity to N = 4 supersymmetric Yang-Mills theory. While the original Kondo problem describes a defect interacting with a free Fermi liquid of itinerant electrons, here the ambient theory is an interacting CFT, and this introduces qualitatively new features into the system. The model arises in string theory by considering the intersection of a stack of M D5-branes with a stack of N D3-branes, at a point in the D3 worldvolume. We analyze the theory holographically, and propose a dictionary between the Kondo problem and antisymmetric Wilson loops in N = 4 SYM. We perform an explicit calculation of the D5 fluctuations in the D3 geometry and determine the spectrum of defect operators. This establishes the stability of the Kondo fixed point together with its basic thermodynamic properties. Known supergravity solutions for Wilson loops allow us to go beyond the probe approximation: the D5s disappear and are replaced by three-form flux piercing a new topologically non-trivial S3 in the corrected geometry. This describes the Kondo model in terms of a geometric transition. A dual matrix model reflects the basic properties of the corrected gravity solution in its eigenvalue distribution.
Sub-barrier capture with quantum diffusion approach
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.
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.
The F-Theorem and F-Maximization
Pufu, Silviu S
2016-01-01
This contribution contains a review of the role of the three-sphere free energy F in recent developments related to the F-theorem and F-maximization. The F-theorem states that for any Lorentz-invariant RG trajectory connecting a conformal field theory CFT_UV in the ultraviolet to a conformal field theory CFT_IR, the F-coefficient decreases: F_UV > F_IR. I provide many examples of CFTs where one can compute F, approximately or exactly, and discuss various checks of the F-theorem. F-maximization is the principle that in an N=2 SCFT, viewed as the deep IR limit of an RG trajectory preserving N=2 supersymmetry, the superconformal R-symmetry maximizes F within the set of all R-symmetries preserved by the RG trajectory. I review the derivation of this result and provide examples.
Ramaswami, Rama
2009-01-01
Digital lecture capture and broadcast solutions have been around for only about 10 years, but are poised for healthy growth. Frost & Sullivan research analysts estimate that the market (which amounts to $25 million currently) will quadruple by 2013. It's still dominated by a few key players, however: Sonic Foundry holds a hefty 40 percent-plus…
A New Algorithm to Optimize Maximal Information Coefficient.
Yuan Chen
Full Text Available The maximal information coefficient (MIC captures dependences between paired variables, including both functional and non-functional relationships. In this paper, we develop a new method, ChiMIC, to calculate the MIC values. The ChiMIC algorithm uses the chi-square test to terminate grid optimization and then removes the restriction of maximal grid size limitation of original ApproxMaxMI algorithm. Computational experiments show that ChiMIC algorithm can maintain same MIC values for noiseless functional relationships, but gives much smaller MIC values for independent variables. For noise functional relationship, the ChiMIC algorithm can reach the optimal partition much faster. Furthermore, the MCN values based on MIC calculated by ChiMIC can capture the complexity of functional relationships in a better way, and the statistical powers of MIC calculated by ChiMIC are higher than those calculated by ApproxMaxMI. Moreover, the computational costs of ChiMIC are much less than those of ApproxMaxMI. We apply the MIC values tofeature selection and obtain better classification accuracy using features selected by the MIC values from ChiMIC.
State selective electron capture at low energies
Bliek, Frederik Willem
1997-01-01
Zolang de mensheid al bestaat, vraagt men zich af hoe de sterren zijn ontstaan die we tijdens een heldere nacht aan de hemel zien staan. Om een antwoord te kunnen geven op deze vraag moeten we ons eerst afvragen hoe we iets kunnen leren over een ster die vaak vele duizenden lichtjaren van ons verwij
State selective electron capture at low energies
Bliek, Frederik Willem
1997-01-01
Zolang de mensheid al bestaat, vraagt men zich af hoe de sterren zijn ontstaan die we tijdens een heldere nacht aan de hemel zien staan. Om een antwoord te kunnen geven op deze vraag moeten we ons eerst afvragen hoe we iets kunnen leren over een ster die vaak vele duizenden lichtjaren van ons verwij
CAPTURED End Evaluation Synthesis Report
Brouwers, J.H.A.M.
2012-01-01
This report provides the findings of the Synthesis Study of the CAPTURED Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the three CAPTURED partners have achieved commendable results. Ten lessons learned are formulated th
Boyer, S
2004-10-15
The Thorium cycle Th{sup 232}/U{sup 233} may face brilliant perspectives through advanced concepts like molten salt reactors or accelerator driven systems but it lacks accurate nuclear data concerning some nuclei. Pa{sup 233} is one of these nuclei, its high activity makes the direct measurement of its radiative neutron capture cross-section almost impossible. This difficulty has been evaded by considering the transfer reaction Th{sup 232}(He{sup 3},p)Pa{sup 234}* in which the Pa{sup 234} nucleus is produced in various excited states according to the amount of energy available in the reaction. The first chapter deals with the thorium cycle and its assets to contribute to the quenching of the fast growing world energy demand. The second chapter gives a detailed description of the experimental setting. A scintillation detector based on deuterated benzene (C{sub 6}D{sub 6}) has been used to counter gamma ray cascades. The third chapter is dedicated to data analysis. In the last chapter we compare our experimental results with ENDF and JENDL data and with computed values from 2 statistical models in the 0-1 MeV neutron energy range. Our results disagree clearly with evaluated data: our values are always above ENDF and JENDL data but tend to near computed values. We have also perform the measurement of the radiative neutron cross-section of Pa{sup 231} for a 110 keV neutron: {sigma}(n,{gamma}) 2.00 {+-} 0.14 barn. (A.C.)
Neutron transmission and capture of 241Am
Sage C.
2013-03-01
Full Text Available A set of neutron transmission and capture experiments based on the Time Of Flight (TOF technique, were performed in order to determine the 241Am capture cross section in the energy range from 0.01 eV to 1 keV. The GELINA facility of the Institute for Reference Materials and Measurements (IRMM served as the neutron source. A pair of C6D6 liquid scintillators was used to register the prompt gamma rays emerging from the americium sample, while a Li-glass detector was used in the transmission setup. Results from the capture and transmission data acquired are consistent with each other, but appear to be inconsistent with the evaluated data files. Resonance parameters have been derived for the data up to the energy of 100 eV.
Maximal inequalities for demimartingales and their applications
WANG XueJun; HU ShuHe
2009-01-01
In this paper,we establish some maximal inequalities for demimartingales which generalize and improve the results of Christofides.The maximal inequalities for demimartingales are used as key inequalities to establish other results including Doob's type maximal inequality for demimartingales,strong laws of large numbers and growth rate for demimartingales and associated random variables.At last,we give an equivalent condition of uniform integrability for demisubmartingales.
Maximal inequalities for demimartingales and their applications
无
2009-01-01
In this paper, we establish some maximal inequalities for demimartingales which generalize and improve the results of Christofides. The maximal inequalities for demimartingales are used as key inequalities to establish other results including Doob’s type maximal inequality for demimartingales, strong laws of large numbers and growth rate for demimartingales and associated random variables. At last, we give an equivalent condition of uniform integrability for demisubmartingales.
Maximizing hydrogen production by cyanobacteria
Bothe, H.; Winkelmann, S.; Boison, G. [Botanical Inst., The Univ. of Cologne, Cologne (Germany)
2008-03-15
When incubated anaerobically, in the light, in the presence of C{sub 2}H{sub 2} and high concentrations of H{sub 2}, both Mo-grown Anabaena variabilis and either Mo- or V-grown Anabaena azotica produce large amounts of H{sub 2} in addition to the H{sub 2} initially added. In contrast, C{sub 2}H{sub 2}-reduction is diminished under these conditions. The additional H{sub 2}-production mainly originates from nitrogenase with the V-enzyme being more effective than the Mo-protein. This enhanced H{sub 2}-production in the presence of added H{sub 2} and C{sub 2}H{sub 2} should be of interest in approaches to commercially exploit solar energy conversion by cyanobacterial photosynthesis for the generation of molecular hydrogen as a clean energy source. (orig.)
Task-oriented maximally entangled states
Agrawal, Pankaj; Pradhan, B, E-mail: agrawal@iopb.res.i, E-mail: bpradhan@iopb.res.i [Institute of Physics, Sachivalaya Marg, Bhubaneswar, Orissa 751 005 (India)
2010-06-11
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.
Inflation in maximal gauged supergravities
Kodama, Hideo [Theory Center, KEK,Tsukuba 305-0801 (Japan); Department of Particles and Nuclear Physics,The Graduate University for Advanced Studies,Tsukuba 305-0801 (Japan); Nozawa, Masato [Dipartimento di Fisica, Università di Milano, and INFN, Sezione di Milano,Via Celoria 16, 20133 Milano (Italy)
2015-05-18
We discuss the dynamics of multiple scalar fields and the possibility of realistic inflation in the maximal gauged supergravity. In this paper, we address this problem in the framework of recently discovered 1-parameter deformation of SO(4,4) and SO(5,3) dyonic gaugings, for which the base point of the scalar manifold corresponds to an unstable de Sitter critical point. In the gauge-field frame where the embedding tensor takes the value in the sum of the 36 and 36’ representations of SL(8), we present a scheme that allows us to derive an analytic expression for the scalar potential. With the help of this formalism, we derive the full potential and gauge coupling functions in analytic forms for the SO(3)×SO(3)-invariant subsectors of SO(4,4) and SO(5,3) gaugings, and argue that there exist no new critical points in addition to those discovered so far. For the SO(4,4) gauging, we also study the behavior of 6-dimensional scalar fields in this sector near the Dall’Agata-Inverso de Sitter critical point at which the negative eigenvalue of the scalar mass square with the largest modulus goes to zero as the deformation parameter s approaches a critical value s{sub c}. We find that when the deformation parameter s is taken sufficiently close to the critical value, inflation lasts more than 60 e-folds even if the initial point of the inflaton allows an O(0.1) deviation in Planck units from the Dall’Agata-Inverso critical point. It turns out that the spectral index n{sub s} of the curvature perturbation at the time of the 60 e-folding number is always about 0.96 and within the 1σ range n{sub s}=0.9639±0.0047 obtained by Planck, irrespective of the value of the η parameter at the critical saddle point. The tensor-scalar ratio predicted by this model is around 10{sup −3} and is close to the value in the Starobinsky model.
Lifetime maximization routing with network coding in wireless multihop networks
DING LiangHui; WU Ping; WANG Hao; PAN ZhiWen; YOU XiaoHu
2013-01-01
In this paper, we consider the lifetime maximization routing with network coding in wireless mul- tihop networks. We first show that lifetime maximization with network coding is different from pure routing, throughput maximization with network coding and energy minimization with network coding. Then we formulate lifetime maximization problems in three different cases of （i） no network coding, （ii） two-way network coding, and （iii） overhearing network coding. To solve these problems, we use flow augmenting routing （FA） for the first case, and then extend the FA with network coding （FANC） by using energy minimized one-hop network coding. After that, we investigate the influence of parameters of FANC, evaluate the performance of FANC with two-way and overhearing network coding schemes and compare it with that without network coding under two different power control models, namely, protocol and physical ones. The results show that the lifetime can be improved significantly by using network coding, and the performance gain of network coding decreases with the increase of flow asymmetry and the power control ability.
Supernova electron capture rates
Martínez-Pinedo, G
1999-01-01
We have calculated the Gamow-Teller strength distributions for the ground states and low lying states of several nuclei that play an important role in the precollapse evolution of supernova. The calculations reproduce the experimental GT distributions nicely. The GT distribution are used to calculate electron capture rates for typical presupernova conditions. The computed rates are noticeably smaller than the presently adopted rates. The possible implications for the supernova evolution are discussed.
Cutting the cost of carbon capture: a case for carbon capture and utilization.
Joos, Lennart; Huck, Johanna M; Van Speybroeck, Veronique; Smit, Berend
2016-10-20
A significant part of the cost for carbon capture and storage (CCS) is related to the compression of captured CO2 to its supercritical state, at 150 bar and typically 99% purity. These stringent conditions may however not always be necessary for specific cases of carbon capture and utilization (CCU). In this manuscript, we investigate how much the parasitic energy of an adsorbent-based carbon capture process may be lowered by utilizing CO2 at 1 bar and adapting the final purity requirement for CO2 from 99% to 70% or 50%. We compare different CO2 sources: the flue gases of coal-fired or natural gas-fired power plants and ambient air. We evaluate the carbon capture performance of over 60 nanoporous materials and determine the influence of the initial and final CO2 purity on the parasitic energy of the carbon capture process. Moreover, we demonstrate the underlying principles of the parasitic energy minimization in more detail using the commercially available NaX zeolite. Finally, the calculated utilization cost of CO2 is compared with the reported prices for CO2 and published costs for CCS.
Tracking Progress in Carbon Capture and Storage
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.
Computing Maximally Supersymmetric Scattering Amplitudes
Stankowicz, James Michael, Jr.
This dissertation reviews work in computing N = 4 super-Yang--Mills (sYM) and N = 8 maximally supersymmetric gravity (mSUGRA) scattering amplitudes in D = 4 spacetime dimensions in novel ways. After a brief introduction and overview in Ch. 1, the various techniques used to construct amplitudes in the remainder of the dissertation are discussed in Ch. 2. This includes several new concepts such as d log and pure integrand bases, as well as how to construct the amplitude using exactly one kinematic point where it vanishes. Also included in this chapter is an outline of the Mathematica package on shell diagrams and numerics.m (osdn) that was developed for the computations herein. The rest of the dissertation is devoted to explicit examples. In Ch. 3, the starting point is tree-level sYM amplitudes that have integral representations with residues that obey amplitude relations. These residues are shown to have corresponding residue numerators that allow a double copy prescription that results in mSUGRA residues. In Ch. 4, the two-loop four-point sYM amplitude is constructed in several ways, showcasing many of the techniques of Ch. 2; this includes an example of how to use osdn. The two-loop five-point amplitude is also presented in a pure integrand representation with comments on how it was constructed from one homogeneous cut of the amplitude. On-going work on the two-loop n-point amplitude is presented at the end of Ch. 4. In Ch. 5, the three-loop four-point amplitude is presented in the d log representation and in the pure integrand representation. In Ch. 6, there are several examples of four- through seven-loop planar diagrams that illustrate how considerations of the singularity structure of the amplitude underpin dual-conformal invariance. Taken with the previous examples, this is additional evidence that the structure known to exist in the planar sector extends to the full theory. At the end of this chapter is a proof that all mSUGRA amplitudes have a pole at
Foland, Andrew Dean
2007-01-01
Energy is the central concept of physics. Unable to be created or destroyed but transformable from one form to another, energy ultimately determines what is and isn''t possible in our universe. This book gives readers an appreciation for the limits of energy and the quantities of energy in the world around them. This fascinating book explores the major forms of energy: kinetic, potential, electrical, chemical, thermal, and nuclear.
Neutron Capture Cross Sections of 236U and 234U
Rundberg, R. S.; Bredeweg, T. A.; Bond, E. M.; Haight, R. C.; Hunt, L. F.; Kronenberg, A.; O'Donnell, J. M.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.
2006-03-01
Accurate neutron capture cross sections of the actinide elements at neutron energies up to 1 MeV are needed to better interpret archived nuclear test data, for post-detonation nuclear attribution, and the Advanced Fuel Cycle Initiative. The Detector for Advance Neutron Capture Experiments, DANCE, has unique capabilities that allow the differentiation of capture gamma rays from fission gamma rays and background gamma rays from scattered neutrons captured by barium isotopes in the barium fluoride scintillators. The DANCE array has a high granularity, 160 scintillators, high efficiency, and nearly 4-π solid angle. Through the use of cuts in cluster multiplicity and calorimetric energy the capture gamma-rays are differentiated from other sources of gamma rays. The preliminary results for the capture cross sections of 236U are in agreement with the ENDF/B-VI evaluation. The preliminary results for 234U lower are than ENDF/B-VI evaluation and are closer to older evaluations.
Are all maximally entangled states pure?
Cavalcanti, D; Terra-Cunha, M O
2005-01-01
In this Letter we study if all maximally entangled states are pure through several entanglement monotones. Our conclusions allow us to generalize the idea of monogamy of entanglement. Then we propose a polygamy of entanglement, which express that if a general multipartite state is maximally entangled it is necessarily factorized by any other system.
Sampling and Representation Complexity of Revenue Maximization
Dughmi, Shaddin; Han, Li; Nisan, Noam
2014-01-01
We consider (approximate) revenue maximization in auctions where the distribution on input valuations is given via "black box" access to samples from the distribution. We observe that the number of samples required -- the sample complexity -- is tightly related to the representation complexity of an approximately revenue-maximizing auction. Our main results are upper bounds and an exponential lower bound on these complexities.
Lisonek, Petr
1996-01-01
our classifications confirmthe maximality of previously known sets, the results in E^7 and E^8are new. Their counterpart in dimension larger than 10is a set of unit vectors with only two values of inner products in the Lorentz space R^{d,1}.The maximality of this set again follows from a bound due...
An ethical justification of profit maximization
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 b...
Alternative trailer configurations for maximizing payloads
Jason D. Thompson; Dana Mitchell; John Klepac
2017-01-01
In order for harvesting contractors to stay ahead of increasing costs, it is imperative that they employ all options to maximize productivity and efficiency. Transportation can account for half the cost to deliver wood to a mill. Contractors seek to maximize truck payload to increase productivity. The Forest Operations Research Unit, Southern Research Station, USDA...
Cohomology of Weakly Reducible Maximal Triangular Algebras
董浙; 鲁世杰
2000-01-01
In this paper, we introduce the concept of weakly reducible maximal triangular algebras φwhich form a large class of maximal triangular algebras. Let B be a weakly closed algebra containing 5φ, we prove that the cohomology spaces Hn(φ, B) (n≥1) are trivial.
Inclusive fitness maximization: An axiomatic approach.
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.
Maximal Hypersurfaces in Spacetimes with Translational Symmetry
Bulawa, Andrew
2016-01-01
We consider four-dimensional vacuum spacetimes which admit a free isometric spacelike R-action. Taking a quotient with respect to the R-action produces a three-dimensional quotient spacetime. We establish several results regarding maximal hypersurfaces (spacelike hypersurfaces of zero mean curvature) in quotient spacetimes. First, we show that complete noncompact maximal hypersurfaces must either be flat cylinders S^1 x R or conformal to the Euclidean plane. Second, we establish a positive mass theorem for certain maximal hypersurfaces. Finally, while it is meaningful to use a bounded lapse when adopting the maximal hypersurface gauge condition in the four-dimensional (asymptotically flat) setting, it is shown here that nontrivial quotient spacetimes admit the maximal hypersurface gauge only with an unbounded lapse.
Capturing the Future: Direct and Indirect Probes of Neutron Capture
Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-08-31
This report documents aspects of direct and indirect neutron capture. The importance of neutron capture rates and methods to determine them are presented. The following conclusions are drawn: direct neutron capture measurements remain a backbone of experimental study; work is being done to take increased advantage of indirect methods for neutron capture; both instrumentation and facilities are making new measurements possible; more work is needed on the nuclear theory side to understand what is needed furthest from stability.
Thermal-neutron capture gamma rays from natural calcium
Gruppelaar, H.; Spilling, P.
1967-01-01
Gamma rays from thermal-neutron capture in natural Ca and enriched 40Ca were investigated with a 5 cm3 Ge(Li) detector. Many low-energy γ-lines have been found. More than 90% of the γ-rays result from capture in 40Ca and about 5% from capture in 44Ca. From the data a decay scheme of 41Ca and a parti
Modeling post-combustion CO2 capture with amine solvents
Léonard, Grégoire; Heyen, Georges
2010-01-01
In order to avoid the emission of large amounts of greenhouse gas, CO2 capture in fossil fuel power plants and subsequent underground CO2 sequestration is studied. The capture occurs by reactive CO2 absorption into chemical solvent systems at moderate temperature (~50°C) followed by solvent regeneration at higher temperature (~120°C). So far, the most employed solvent for acid gas capture is monoethanolamine (MEA). One main drawback of this technology is the high energy consumption necessary ...
Astrophysical S factor for {alpha}-capture on {sup 115}Sn
Filipescu, D.; Cata-Danil, I.; Ivascu, M.; Bucurescu, D.; Zamfir, N.V.; Glodariu, T.; Stroe, L.; Mihai, C.; Marginean, N.; Ghita, D.G.; Marginean, R.; Suliman, G.; Sava, T.; Pascu, S. [Horia-Hulubei National Institute for Physics and Nuclear Engineering, Magurele-Ilfov (Romania); Cata-Danil, G. [Physics Department, University Politehnica, Bucharest (Romania)
2009-07-01
The s and r processes calculations can only account for 50% of the {sup 115}Sn abundance, and recent p process calculations cannot explain the remaining fraction. For this reason, the experimental measurement of the S factor of {alpha} capture on {sup 115}Sn is of high importance in explaining the origin of {sup 115}Sn. The cross section of {sup 115}Sn({alpha}, {gamma}){sup 119}Te reaction has been measured in the effective center of mass energy from 9.5 to 14.7 MeV. Enriched self-supporting {sup 115}Sn (56%) foils were bombarded with {alpha} beam delivered by the Bucharest IFIN-HH Tandem Accelerator. The induced activity of {sup 119}Te was measured with two large volume GeHP detectors in close geometry to maximize the detector efficiency. The experimental cross section and astrophysical S factor are compared with statistical model predictions for different global {alpha}-nucleus optical potential.
Lunar Sulfur Capture System Project
National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to capture greater than 90 percent of sulfur gases evolved during thermal treatment of lunar soils....
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.
Habibi, Hamed; Rahimi Nohooji, Hamed; Howard, Ian
2017-04-01
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.
Single ionization and electron capture in He2++Na collisions
Knoop, S; Olson, RE; Ott, H; Hasan, VG; Morgenstern, R; Hoekstra, R
2005-01-01
Single-electron capture and ionization in He2+ + Na collisions at energies around the matching velocity (2-13 keV amu(-1)) have been studied both experimentally and theoretically. State-selective cross section for capture into the n = 2, 3, 4 and n >= 5, and the ionization cross section as well as d
Multiphonon capture processes in self-assembled quantum dots
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 that ...
Neutron resonance capture applied to some prehistoric bronze axes
Postma, H.; Butler, J. J.; Schillebeeckx, P.; van Eijk, C. W. E.
2007-01-01
The elemental analysis of materials and objects on the basis of neutron resonance capture by nuclei as a function of neutron energy is briefly explained. The feasibility of neutron resonance capture analysis (NRCA) is demonstrated with five prehistoric '' bronze '' axes of different kinds and comple
Feasibility study of CO2 capture by anti-sublimation
Schach, M.O.; Oyarzun, B.A.; Schramm, H.; Schneider, R.; Repke, J.U.
2011-01-01
Processes for carbon capture and storage have the drawback of high energy demand. In this work the application of CO2 capture by anti-sublimation is analyzed. The process was simulated using Aspen Plus. Process description is accomplished by phase equilibria models which are able to reproduce the
Feasibility study of CO2 capture by anti-sublimation
Schach, M.O.; Oyarzun, B.A.; Schramm, H.; Schneider, R.; Repke, J.U.
2011-01-01
Processes for carbon capture and storage have the drawback of high energy demand. In this work the application of CO2 capture by anti-sublimation is analyzed. The process was simulated using Aspen Plus. Process description is accomplished by phase equilibria models which are able to reproduce the va
Are all maximally entangled states pure?
Cavalcanti, D.; Brandão, F. G. S. L.; Terra Cunha, M. O.
2005-10-01
We study if all maximally entangled states are pure through several entanglement monotones. In the bipartite case, we find that the same conditions which lead to the uniqueness of the entropy of entanglement as a measure of entanglement exclude the existence of maximally mixed entangled states. In the multipartite scenario, our conclusions allow us to generalize the idea of the monogamy of entanglement: we establish the polygamy of entanglement, expressing that if a general state is maximally entangled with respect to some kind of multipartite entanglement, then it is necessarily factorized of any other system.
An ethical justification of profit maximization
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...
Robust utility maximization in a discontinuous filtration
Jeanblanc, Monique; Ngoupeyou, Armand
2012-01-01
We study a problem of utility maximization under model uncertainty with information including jumps. We prove first that the value process of the robust stochastic control problem is described by the solution of a quadratic-exponential backward stochastic differential equation with jumps. Then, we establish a dynamic maximum principle for the optimal control of the maximization problem. The characterization of the optimal model and the optimal control (consumption-investment) is given via a forward-backward system which generalizes the result of Duffie and Skiadas (1994) and El Karoui, Peng and Quenez (2001) in the case of maximization of recursive utilities including model with jumps.
Robertson, William C
2002-01-01
Confounded by kinetic energy? Suspect that teaching about simple machines isn t really so simple? Exasperated by electricity? If you fear the study of energy is beyond you, this entertaining book will do more than introduce you to the topic. It will help you actually understand it. At the book s heart are easy-to-grasp explanations of energy basics work, kinetic energy, potential energy, and the transformation of energy and energy as it relates to simple machines, heat energy, temperature, and heat transfer. Irreverent author Bill Robertson suggests activities that bring the basic concepts of energy to life with common household objects. Each chapter ends with a summary and an applications section that uses practical examples such as roller coasters and home heating systems to explain energy transformations and convection cells. The final chapter brings together key concepts in an easy-to-grasp explanation of how electricity is generated. Energy is the second book in the Stop Faking It! series published by NS...
Laser capture microdissection: Arcturus(XT) infrared capture and UV cutting methods.
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.
HEALTH INSURANCE: CONTRIBUTIONS AND REIMBURSEMENT MAXIMAL
HR Division
2000-01-01
Affected by both the salary adjustment index on 1.1.2000 and the evolution of the staff members and fellows population, the average reference salary, which is used as an index for fixed contributions and reimbursement maximal, has changed significantly. An adjustment of the amounts of the reimbursement maximal and the fixed contributions is therefore necessary, as from 1 January 2000.Reimbursement maximalThe revised reimbursement maximal will appear on the leaflet summarising the benefits for the year 2000, which will soon be available from the divisional secretariats and from the AUSTRIA office at CERN.Fixed contributionsThe fixed contributions, applicable to some categories of voluntarily insured persons, are set as follows (amounts in CHF for monthly contributions):voluntarily insured member of the personnel, with complete coverage:815,- (was 803,- in 1999)voluntarily insured member of the personnel, with reduced coverage:407,- (was 402,- in 1999)voluntarily insured no longer dependent child:326,- (was 321...
Maximizing throughput by evaluating critical utilization paths
Weeda, P.J.
1991-01-01
Recently the relationship between batch structure, bottleneck machine and maximum throughput has been explored for serial, convergent and divergent process configurations consisting of two machines and three processes. In three of the seven possible configurations a multiple batch structure maximize
Relationship between maximal exercise parameters and individual ...
Relationship between maximal exercise parameters and individual time trial ... It is widely accepted that the ventilatory threshold (VT) is an important ... This study investigated whether the physiological responses during a 20km time trial (TT) ...
Neutron capture strategy and technique developments for GNEP
Couture, Aaron Joseph [Los Alamos National Laboratory
2008-01-01
The initial three years of neutron capture measurements have been very successful in providing data for the Advanced Fuel Cycle Initiative/Global Nuclear Energy Partnership (AFCI/GNEP) program. Now that the most straightforward measurements have been completed, additional technical challenges face future measurements. In particular, techniques are needed to perform measurements that exhibit at least one of three major problems -- large fission:capture ratios, large capture:capture ratios, and high intrinsic activity samples. This paper will set forward a plan for attacking these technical challenges and moving forward with future measurements.
Neutron capture reactions at DANCE
Bredeweg, T. A.
2008-05-01
The Detector for Advanced Neutron Capture Experiments (DANCE) is a 4π BaF2 array consisting of 160 active detector elements. The primary purpose of the array is to perform neutron capture cross section measurements on small (>~100 μg) and/or radioactive (DANCE we have performed neutron capture cross section measurements on a wide array of medium to heavy mass nuclides. Measurements to date include neutron capture cross sections on 241,243Am, neutron capture and neutron-induced fission cross sections and capture-to-fission ratio (α = σγ/σf) for 235U using a new fission-tagging detector as well as neutron capture cross sections for several astrophysics branch-point nuclei. Results from several of these measurements will be presented along with a discussion of additional physics information that can be extracted from the DANCE data.
Simple technique for maximal thoracic muscle harvest.
Marshall, M Blair; Kaiser, Larry R; Kucharczuk, John C
2004-04-01
We present a modification of technique for standard muscle flap harvest, the placement of cutaneous traction sutures. This technique allows for maximal dissection of the thoracic muscles even through minimal incisions. Through improved exposure and traction, complete dissection of the muscle bed can be performed and the tissue obtained maximized. Because more muscle bulk is obtained with this technique, the need for a second muscle may be prevented.
MAXIMAL POINTS OF A REGULAR TRUTH FUNCTION
Every canonical linearly separable truth function is a regular function, but not every regular truth function is linearly separable. The most...promising method of determining which of the regular truth functions are linearly separable r quires finding their maximal and minimal points. In this...report is developed a quick, systematic method of finding the maximal points of any regular truth function in terms of its arithmetic invariants. (Author)
Maximal Subgroups of Skew Linear Groups
M. Mahdavi-Hezavehi
2002-01-01
Let D be an infinite division algebra of finite dimension over its centre Z(D) = F, and n a positive integer. The structure of maximal subgroups of skew linear groups are investigated. In particular, assume N is a normal subgroup of GLn(D) and M is a maximal subgroup of N containing Z(N). It is shown that if M/Z(N) is finite, then N is central.
Additive Approximation Algorithms for Modularity Maximization
Kawase, Yasushi; Matsui, Tomomi; Miyauchi, Atsushi
2016-01-01
The modularity is a quality function in community detection, which was introduced by Newman and Girvan (2004). Community detection in graphs is now often conducted through modularity maximization: given an undirected graph $G=(V,E)$, we are asked to find a partition $\\mathcal{C}$ of $V$ that maximizes the modularity. Although numerous algorithms have been developed to date, most of them have no theoretical approximation guarantee. Recently, to overcome this issue, the design of modularity max...
Robust automated knowledge capture.
Stevens-Adams, Susan Marie; Abbott, Robert G.; Forsythe, James Chris; Trumbo, Michael Christopher Stefan; Haass, Michael Joseph; Hendrickson, Stacey M. Langfitt
2011-10-01
This report summarizes research conducted through the Sandia National Laboratories Robust Automated Knowledge Capture Laboratory Directed Research and Development project. The objective of this project was to advance scientific understanding of the influence of individual cognitive attributes on decision making. The project has developed a quantitative model known as RumRunner that has proven effective in predicting the propensity of an individual to shift strategies on the basis of task and experience related parameters. Three separate studies are described which have validated the basic RumRunner model. This work provides a basis for better understanding human decision making in high consequent national security applications, and in particular, the individual characteristics that underlie adaptive thinking.
Capturing the uncultivated majority
Green, Brian D.; Keller, Martin
2007-04-02
The metagenomic analysis of environmental microbialcommunities continues to be a rapidly developing area of study. DNAisolation, the first step in capturing the uncultivated majority, hasseen many advances in recent years. Protocols have been developed todistinguish DNA from live versus dead cells and to separate extracellularfrom intracellular DNA. Looking to increase our understanding of the rolethat members of a microbial community play in ecological processes,several techniques have been developed that are enabling greater indepthanalysis of environmental metagenomes. These include the development ofenvironmental gene tags and the serial analysis of 16S rRNA gene sequencetags. In addition, new screening methods have been designed to select forspecific functional genes within metagenomic libraries. Finally, newcultivation methods continue to be developed to improve our ability tocapture a greater diversity of microorganisms within theenvironment.
Smith, James P; Lannin, Timothy B; Syed, Yusef; Santana, Steven M; Kirby, Brian J
2014-02-01
The enrichment and isolation of rare cells from complex samples, such as circulating tumor cells (CTCs) from whole blood, is an important engineering problem with widespread clinical applications. One approach uses a microfluidic obstacle array with an antibody surface functionalization to both guide cells into contact with the capture surface and to facilitate adhesion; geometrically enhanced differential immunocapture is a design strategy in which the array is designed to promote target cell–obstacle contact and minimize other interactions (Gleghorn et al. 2010; Kirby et al. 2012). We present a simulation that uses capture experiments in a simple Hele-Shaw geometry (Santana et al. 2012) to inform a target-cell-specific capture model that can predict capture probability in immunocapture microdevices of any arbitrary complex geometry. We show that capture performance is strongly dependent on the array geometry, and that it is possible to select an obstacle array geometry that maximizes capture efficiency (by creating combinations of frequent target cell–obstacle collisions and shear stress low enough to support capture), while simultaneously enhancing purity by minimizing nonspecific adhesion of both smaller contaminant cells (with infrequent cell–obstacle collisions) and larger contaminant cells (by focusing those collisions into regions of high shear stress).
Synthesis of optimal adsorptive carbon capture processes.
chang, Y.; Cozad, A.; Kim, H.; Lee, A.; Vouzis, P.; Konda, M.; Simon, A.; Sahinidis, N.; Miller, D.
2011-01-01
Solid sorbent carbon capture systems have the potential to require significantly lower regeneration energy compared to aqueous monoethanol amine (MEA) systems. To date, the majority of work on solid sorbents has focused on developing the sorbent materials themselves. In order to advance these technologies, it is necessary to design systems that can exploit the full potential and unique characteristics of these materials. The Department of Energy (DOE) recently initiated the Carbon Capture Simulation Initiative (CCSI) to develop computational tools to accelerate the commercialization of carbon capture technology. Solid sorbents is the first Industry Challenge Problem considered under this initiative. An early goal of the initiative is to demonstrate a superstructure-based framework to synthesize an optimal solid sorbent carbon capture process. For a given solid sorbent, there are a number of potential reactors and reactor configurations consisting of various fluidized bed reactors, moving bed reactors, and fixed bed reactors. Detailed process models for these reactors have been modeled using Aspen Custom Modeler; however, such models are computationally intractable for large optimization-based process synthesis. Thus, in order to facilitate the use of these models for process synthesis, we have developed an approach for generating simple algebraic surrogate models that can be used in an optimization formulation. This presentation will describe the superstructure formulation which uses these surrogate models to choose among various process alternatives and will describe the resulting optimal process configuration.
Capture-Gated Fast Neutron Spectroscopy
Mumm, H. P.; Abdurashitov, J. N.; Beise, E. J.; Breuer, H.; Gavrin, V. N.; Heimbach, C. R.; Langford, T. J.; Mendenhall, M.; Nico, J. S.; Shikhin, A. A.
2015-10-01
We present recent developments in fast neutron detection using segmented spectrometers based on the principle of capture-gating. Our approach employs an organic scintillator to detect fast neutrons through their recoil interaction with protons in the scintillator. The neutrons that thermalize and are captured produce a signal indicating that the event was due to a neutron recoil and that the full energy of the neutron was deposited. The delayed neutron capture also serves to discriminate against uncorrelated background events. The segmentation permits reconstruction of the initial neutron energy despite the nonlinear response of the scintillator. We have constructed spectrometers using both He-3 proportional counters and Li-6 doping as capture agents in plastic and liquid organic scintillators. We discuss the operation of the spectrometers for the measurement of low levels of fast neutrons for several applications, including the detection of very low-activity neutron sources and the characterization of the flux and spectrum of fast neutrons at the Earth's surface and in the underground environment.
Maximal Frequent Itemset Generation Using Segmentation Apporach
M.Rajalakshmi
2011-09-01
Full Text Available Finding frequent itemsets in a data source is a fundamental operation behind Association Rule Mining.Generally, many algorithms use either the bottom-up or top-down approaches for finding these frequentitemsets. When the length of frequent itemsets to be found is large, the traditional algorithms find all thefrequent itemsets from 1-length to n-length, which is a difficult process. This problem can be solved bymining only the Maximal Frequent Itemsets (MFS. Maximal Frequent Itemsets are frequent itemsets whichhave no proper frequent superset. Thus, the generation of only maximal frequent itemsets reduces thenumber of itemsets and also time needed for the generation of all frequent itemsets as each maximal itemsetof length m implies the presence of 2m-2 frequent itemsets. Furthermore, mining only maximal frequentitemset is sufficient in many data mining applications like minimal key discovery and theory extraction. Inthis paper, we suggest a novel method for finding the maximal frequent itemset from huge data sourcesusing the concept of segmentation of data source and prioritization of segments. Empirical evaluationshows that this method outperforms various other known methods.
Natural selection and the maximization of fitness.
Birch, Jonathan
2016-08-01
The notion that natural selection is a process of fitness maximization gets a bad press in population genetics, yet in other areas of biology the view that organisms behave as if attempting to maximize their fitness remains widespread. Here I critically appraise the prospects for reconciliation. I first distinguish four varieties of fitness maximization. I then examine two recent developments that may appear to vindicate at least one of these varieties. The first is the 'new' interpretation of Fisher's fundamental theorem of natural selection, on which the theorem is exactly true for any evolving population that satisfies some minimal assumptions. The second is the Formal Darwinism project, which forges links between gene frequency change and optimal strategy choice. In both cases, I argue that the results fail to establish a biologically significant maximization principle. I conclude that it may be a mistake to look for universal maximization principles justified by theory alone. A more promising approach may be to find maximization principles that apply conditionally and to show that the conditions were satisfied in the evolution of particular traits.
Climate Strategy with CO2 Capture from the Air
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.
Jois, Manjunath Holaykoppa Nanjunda
The conventional Influence Maximization problem is the problem of finding such a team (a small subset) of seed nodes in a social network that would maximize the spread of influence over the whole network. This paper considers a lottery system aimed at maximizing the awareness spread to promote energy conservation behavior as a stochastic Influence Maximization problem with the constraints ensuring lottery fairness. The resulting Multi-Team Influence Maximization problem involves assigning the probabilities to multiple teams of seeds (interpreted as lottery winners) to maximize the expected awareness spread. Such a variation of the Influence Maximization problem is modeled as a Linear Program; however, enumerating all the possible teams is a hard task considering that the feasible team count grows exponentially with the network size. In order to address this challenge, we develop a column generation based approach to solve the problem with a limited number of candidate teams, where new candidates are generated and added to the problem iteratively. We adopt a piecewise linear function to model the impact of including a new team so as to pick only such teams which can improve the existing solution. We demonstrate that with this approach we can solve such influence maximization problems to optimality, and perform computational study with real-world social network data sets to showcase the efficiency of the approach in finding lottery designs for optimal awareness spread. Lastly, we explore other possible scenarios where this model can be utilized to optimally solve the otherwise hard to solve influence maximization problems.
Effects of nonstatistical hyperfine populations in muon capture by polarized nuclei
Hambro, L
1975-01-01
The nonstatistical populations of the hyperfine (HF) levels in muonic atoms brought about by the polarization of the nuclear targets and their influence on the nuclear muon capture probability are considered. The nuclear-capture rates from the upper and lower HF states of the 1s atomic orbit can be markedly different. The usefulness of muon capture by polarized nuclei to probe qualitatively, and possible quantitatively, the difference between the hyperfine capture rates is demonstrated. The best targets to exploit this effect are those for which the hyperfine conversion rate is small in comparison to muon disappearance rate, and which can be polarized maximally to a degree reliably determinable. (18 refs).
Thermal neutron capture gamma-rays
Tuli, J.K.
1983-01-01
The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,..cap alpha..), 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,..gamma..) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide.
Annual Report: Carbon Capture (30 September 2012)
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
Optimal Design of Piezoelectric Materials for Maximal Energy Harvesting
2015-06-01
Ak cos(ωt−φ) = mY0ω2 cos(ωt) . (2.5) Utilizing the trigonometric identities cos(ωt − φ) = cos(ωt)cos(φ) + sin(ωt)sin(φ) and sin(ωt−φ) = sin(ωt)cos(φ... trigonometric identities cos(x− y)= cosxcosy+ sinxsiny and sin(x− y) = sinxcosy− cosxsiny we can rewrite Equation (3.18) as −AUωbase cos(ωbaset)+C0Vpωbase [ cos...3.32) Using Equations (3.30) and (3.32) and the trigonometric identity cos2(φbase)+sin2(φbase)= 1, we find−ωbase2 + [ wSC2 ] + C0A 2ωbase2R2 (1
Neutron capture cross sections from Surrogate measurements
Scielzo N.D.
2010-03-01
Full Text Available The prospects for determining cross sections for compound-nuclear neutron-capture reactions from Surrogate measurements are investigated. Calculations as well as experimental results are presented that test the Weisskopf-Ewing approximation, which is employed in most analyses of Surrogate data. It is concluded that, in general, one has to go beyond this approximation in order to obtain (n,γ cross sections of sufficient accuracy for most astrophysical and nuclear-energy applications.
Welfare-maximizing and revenue-maximizing tariffs with a few domestic firms
Bruno Larue; Jean-Philippe Gervais
2002-01-01
In this paper we compare the orthodox optimal tariff formula with the appropriate welfare-maximizing tariff when there are a few producing or importing firms. The welfare-maximizing tariff can be very low, voire negative in some cases, while in others it can even exceed the maximum-revenue tariff. The relationship between the welfare-maximizing tariff and the number of firms need not be monotonically increasing, because the tariff is not strictly used to internalize terms of trade externality...
Thermal Propulsion Capture System Heat Exchanger Design
Richard, Evan M.
2016-01-01
One of the biggest challenges of manned spaceflight beyond low earth orbit and the moon is harmful radiation that astronauts would be exposed to on their long journey to Mars and further destinations. Using nuclear energy has the potential to be a more effective means of propulsion compared to traditional chemical engines (higher specific impulse). An upper stage nuclear engine would allow astronauts to reach their destination faster and more fuel efficiently. Testing these engines poses engineering challenges due to the need to totally capture the engine exhaust. The Thermal Propulsion Capture System is a concept for cost effectively and safely testing Nuclear Thermal Engines. Nominally, hydrogen exhausted from the engine is not radioactive, but is treated as such in case of fuel element failure. The Thermal Propulsion Capture System involves injecting liquid oxygen to convert the hydrogen exhaust into steam. The steam is then cooled and condensed into liquid water to allow for storage. The Thermal Propulsion Capture System concept for ground testing of a nuclear powered engine involves capturing the engine exhaust to be cooled and condensed before being stored. The hydrogen exhaust is injected with liquid oxygen and burned to form steam. That steam must be cooled to saturation temperatures before being condensed into liquid water. A crossflow heat exchanger using water as a working fluid will be designed to accomplish this goal. Design a cross flow heat exchanger for the Thermal Propulsion Capture System testing which: Eliminates the need for water injection cooling, Cools steam from 5800 F to saturation temperature, and Is efficient and minimizes water requirement.
Reconciling Coulomb breakup and neutron radiative capture
Capel, P.; Nollet, Y.
2017-07-01
The Coulomb-breakup method to extract the cross section for neutron radiative capture at astrophysical energies is analyzed in detail. In particular, its sensitivity to the description of the neutron-core continuum is ascertained. We consider the case of 14C(n ,γ )15C for which both the radiative capture at low energy and the Coulomb breakup of 15C into 14C+n on Pb at 68 MeV/nucleon have been measured with accuracy. We confirm the direct proportionality of the cross section for both reactions to the square of the asymptotic normalization constant of 15C observed by Summers and Nunes [Phys. Rev. C 78, 011601(R) (2008), 10.1103/PhysRevC.78.011601], but we also show that the 14C-n continuum plays a significant role in the calculations. Fortunately, the method proposed by Summers and Nunes can be improved to absorb that continuum dependence. We show that a more precise radiative-capture cross section can be extracted selecting the breakup data at forward angles and low 14C-n relative energies.
Trojan capture by terrestrial planets
Schwarz, Richard
2016-01-01
The paper is devoted to investigate the capture of asteroids by Venus, Earth and Mars into the 1:1 mean motion resonance especially into Trojan orbits. Current theoretical studies predict that Trojan asteroids are a frequent by-product of the planet formation. This is not only the case for the outer giant planets, but also for the terrestrial planets in the inner Solar System. By using numerical integrations, we investigated the capture efficiency and the stability of the captured objects. We found out that the capture efficiency is larger for the planets in the inner Solar System compared to the outer ones, but most of the captured Trojan asteroids are not long term stable. This temporary captures caused by chaotic behaviour of the objects were investigated without any dissipative forces. They show an interesting dynamical behaviour of mixing like jumping from one Lagrange point to the other one.
Achenbach, Joel
2000-03-01
Captured by Aliens is a long and twisted voyage from science to the supernatural and back again. I hung out in Roswell, N.M., spent time with the Mars Society, met a guy who was figuring out the best way to build a spaceship to go to Alpha Centauri. I visited the set of the X-Files and talked to Mulder and Scully. One day over breakfast I was told by NASA administrator Dan Goldin, We live in a fog, man! He wants the big answers to the big questions. I spent a night in the base of a huge radio telescope in the boondocks of West Virginia, awaiting the signal from the aliens. I was hypnotized in a hotel room by someone who suspected that I'd been abducted by aliens and that this had triggered my interest in the topic. In the last months of his life, I talked to Carl Sagan, who believed that the galaxy riots with intelligent civilizations. He's my hero, for his steadfast adherence to the scientific method. What I found in all this is that the big question that needs immediate attention is not what's out THERE, but what's going on HERE, on Earth, and why we think the way we do, and how we came to be here in the first place.
Welcomme, Robin L; Cowx, Ian G; Coates, David; Béné, Christophe; Funge-Smith, Simon; Halls, Ashley; Lorenzen, Kai
2010-09-27
The reported annual yield from inland capture fisheries in 2008 was over 10 million tonnes, although real catches are probably considerably higher than this. Inland fisheries are extremely complex, and in many cases poorly understood. The numerous water bodies and small rivers are inhabited by a wide range of species and several types of fisher community with diversified livelihood strategies for whom inland fisheries are extremely important. Many drivers affect the fisheries, including internal fisheries management practices. There are also many drivers from outside the fishery that influence the state and functioning of the environment as well as the social and economic framework within which the fishery is pursued. The drivers affecting the various types of inland water, rivers, lakes, reservoirs and wetlands may differ, particularly with regard to ecosystem function. Many of these depend on land-use practices and demand for water which conflict with the sustainability of the fishery. Climate change is also exacerbating many of these factors. The future of inland fisheries varies between continents. In Asia and Africa the resources are very intensely exploited and there is probably little room for expansion; it is here that resources are most at risk. Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production.
Gould, William R.; Kendall, William L.
2013-01-01
Capture-recapture methods were initially developed to estimate human population abundance, but since that time have seen widespread use for fish and wildlife populations to estimate and model various parameters of population, metapopulation, and disease dynamics. Repeated sampling of marked animals provides information for estimating abundance and tracking the fate of individuals in the face of imperfect detection. Mark types have evolved from clipping or tagging to use of noninvasive methods such as photography of natural markings and DNA collection from feces. Survival estimation has been emphasized more recently as have transition probabilities between life history states and/or geographical locations, even where some states are unobservable or uncertain. Sophisticated software has been developed to handle highly parameterized models, including environmental and individual covariates, to conduct model selection, and to employ various estimation approaches such as maximum likelihood and Bayesian approaches. With these user-friendly tools, complex statistical models for studying population dynamics have been made available to ecologists. The future will include a continuing trend toward integrating data types, both for tagged and untagged individuals, to produce more precise and robust population models.
Maximizing Complementary Quantities by Projective Measurements
M. Souza, Leonardo A.; Bernardes, Nadja K.; Rossi, Romeu
2017-04-01
In this work, we study the so-called quantitative complementarity quantities. We focus in the following physical situation: two qubits ( q A and q B ) are initially in a maximally entangled state. One of them ( q B ) interacts with a N-qubit system ( R). After the interaction, projective measurements are performed on each of the qubits of R, in a basis that is chosen after independent optimization procedures: maximization of the visibility, the concurrence, and the predictability. For a specific maximization procedure, we study in detail how each of the complementary quantities behave, conditioned on the intensity of the coupling between q B and the N qubits. We show that, if the coupling is sufficiently "strong," independent of the maximization procedure, the concurrence tends to decay quickly. Interestingly enough, the behavior of the concurrence in this model is similar to the entanglement dynamics of a two qubit system subjected to a thermal reservoir, despite that we consider finite N. However, the visibility shows a different behavior: its maximization is more efficient for stronger coupling constants. Moreover, we investigate how the distinguishability, or the information stored in different parts of the system, is distributed for different couplings.
The Generic Data Capture Facility
Connell, Edward B.; Barnes, William P.; Stallings, William H.
The Generic Data Capture Facility, which can provide data capture support for a variety of different types of spacecraft while enabling operations costs to be carefully controlled, is discussed. The data capture functions, data protection, isolation of users from data acquisition problems, data reconstruction, and quality and accounting are addressed. The TDM and packet data formats utilized by the system are described, and the development of generic facilities is considered.
2003-01-01
Canada, Britain, and Spain. We found that the energy industry is not in crisis ; however, U.S. government policies, laws, dollars, and even public...CEIMAT (Centro de Investagaciones Energeticas , Medioambeintales y Tecnologicas) Research and development Page 3 of 28ENERGY 8/10/04http://www.ndu.edu...meet an emerging national crisis (war), emergency (natural disaster), or major impact event (Y2K). Certain resources are generally critical to the
Muon capture for the front end of a muon collider
Neuffer, D
2011-01-01
We discuss the design of the muon capture front end for a \\mu+-\\mu- Collider. In the front end, a proton bunch on a target creates secondary pions that drift into a capture transport channel, decaying into muons. A sequence of rf cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. The muons are then cooled and accelerated to high energy into a storage ring for high-energy high luminosity collisions. Our initial design is based on the somewhat similar front end of the International Design Study (IDS) neutrino factory.
Muscle trade-offs in a power-amplified prey capture system.
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.
Polyploidy Induction of Pteroceltis tatarinowii Maxim
Lin ZHANG; Feng WANG; Zhongkui SUN; Cuicui ZHU; Rongwei CHEN
2015-01-01
3%Objective] This study was conducted to obtain tetraploid Pteroceltis tatari-nowi Maxim. with excel ent ornamental traits. [Method] The stem apex growing points of Pteroceltis tatarinowi Maxim. were treated with different concentrations of colchicine solution for different hours to figure out a proper method and obtain poly-ploids. [Result] The most effective induction was obtained by treatment with 0.6%-0.8% colchicine for 72 h with 34.2% mutation rate. Flow cytometry and chromosome observation of the stem apex growing point of P. tatarinowi Maxim. proved that the tetraploid plants were successful y obtained with chromosome number 2n=4x=36. [Conclusion] The result not only fil s the blank of polyploid breeding of P. tatarinowi , but also provides an effective way to broaden the methods of cultivation of fast-growing, high-quality, disease-resilience, new varieties of Pteroceltis.
Quantum theory allows for absolute maximal contextuality
Amaral, Barbara; Cunha, Marcelo Terra; Cabello, Adán
2015-12-01
Contextuality is a fundamental feature of quantum theory and a necessary resource for quantum computation and communication. It is therefore important to investigate how large contextuality can be in quantum theory. Linear contextuality witnesses can be expressed as a sum S of n probabilities, and the independence number α and the Tsirelson-like number ϑ of the corresponding exclusivity graph are, respectively, the maximum of S for noncontextual theories and for the theory under consideration. A theory allows for absolute maximal contextuality if it has scenarios in which ϑ /α approaches n . Here we show that quantum theory allows for absolute maximal contextuality despite what is suggested by the examination of the quantum violations of Bell and noncontextuality inequalities considered in the past. Our proof is not constructive and does not single out explicit scenarios. Nevertheless, we identify scenarios in which quantum theory allows for almost-absolute-maximal contextuality.
The maximal process of nonlinear shot noise
Eliazar, Iddo; Klafter, Joseph
2009-05-01
In the nonlinear shot noise system-model shots’ statistics are governed by general Poisson processes, and shots’ decay-dynamics are governed by general nonlinear differential equations. In this research we consider a nonlinear shot noise system and explore the process tracking, along time, the system’s maximal shot magnitude. This ‘maximal process’ is a stationary Markov process following a decay-surge evolution; it is highly robust, and it is capable of displaying both a wide spectrum of statistical behaviors and a rich variety of random decay-surge sample-path trajectories. A comprehensive analysis of the maximal process is conducted, including its Markovian structure, its decay-surge structure, and its correlation structure. All results are obtained analytically and in closed-form.
Absence of parasympathetic reactivation after maximal exercise.
de Oliveira, Tiago Peçanha; de Alvarenga Mattos, Raphael; da Silva, Rhenan Bartels Ferreira; Rezende, Rafael Andrade; de Lima, Jorge Roberto Perrout
2013-03-01
The ability of the human organism to recover its autonomic balance soon after physical exercise cessation has an important impact on the individual's health status. Although the dynamics of heart rate recovery after maximal exercise has been studied, little is known about heart rate variability after this type of exercise. The aim of this study is to analyse the dynamics of heart rate and heart rate variability recovery after maximal exercise in healthy young men. Fifteen healthy male subjects (21·7 ± 3·4 years; 24·0 ± 2·1 kg m(-2) ) participated in the study. The experimental protocol consisted of an incremental maximal exercise test on a cycle ergometer, until maximal voluntary exhaustion. After the test, recovery R-R intervals were recorded for 5 min. From the absolute differences between peak heart rate values and the heart rate values at 1 and 5 min of the recovery, the heart rate recovery was calculated. Postexercise heart rate variability was analysed from calculations of the SDNN and RMSSD indexes, in 30-s windows (SDNN(30s) and RMSSD(30s) ) throughout recovery. One and 5 min after maximal exercise cessation, the heart rate recovered 34·7 (±6·6) and 75·5 (±6·1) bpm, respectively. With regard to HRV recovery, while the SDNN(30s) index had a slight increase, RMSSD(30s) index remained totally suppressed throughout the recovery, suggesting an absence of vagal modulation reactivation and, possibly, a discrete sympathetic withdrawal. Therefore, it is possible that the main mechanism associated with the fall of HR after maximal exercise is sympathetic withdrawal or a vagal tone restoration without vagal modulation recovery. © 2012 The Authors Clinical Physiology and Functional Imaging © 2012 Scandinavian Society of Clinical Physiology and Nuclear Medicine.
Maximizing band gaps in plate structures
Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard
2006-01-01
Band gaps, i.e., frequency ranges in which waves cannot propagate, can be found in elastic structures for which there is a certain periodic modulation of the material properties or structure. In this paper, we maximize the band gap size for bending waves in a Mindlin plate. We analyze an infinite...... periodic plate using Bloch theory, which conveniently reduces the maximization problem to that of a single base cell. Secondly, we construct a finite periodic plate using a number of the optimized base cells in a postprocessed version. The dynamic properties of the finite plate are investigated...
Maximal and Minimal Congruences on Some Semigroups
Jintana SANWONG; Boorapa SINGHA; R.P.SULLIVAN
2009-01-01
In 2006,Sanwong and Sullivan described the maximal congruences on the semigroup N consisting of all non-negative integers under standard multiplication,and on the semigroup T(X) consisting of all total transformations of an infinite set X under composition. Here,we determine all maximal congruences on the semigroup Zn under multiplication modulo n. And,when Y X,we do the same for the semigroup T(X,Y) consisting of all elements of T(X) whose range is contained in Y. We also characterise the minimal congruences on T(X,Y).
Maximizing oil yields may not optimize economics
1987-03-01
The Los Alamos National Laboratory has used the ASPEN computer code to calculate the economics of different hydroretorting conditions. When the oil yield was maximized and a oil shale plant designed around this process, the costs turned out much higher than expected. However, calculations based on runs of less than maximum yields showed lower cost estimates. It is recommended that future efforts should be concentrated on minimizing production costs rather than maximizing yields. An oil shale plant has been designed around minimum production cost, but has not been able to be tested experimentally.
Maximal Inequalities for Dependent Random Variables
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...
Singularity Structure of Maximally Supersymmetric Scattering Amplitudes
Arkani-Hamed, Nima; Bourjaily, Jacob L.; Cachazo, Freddy
2014-01-01
We present evidence that loop amplitudes in maximally supersymmetric (N=4) Yang-Mills theory (SYM) beyond the planar limit share some of the remarkable structures of the planar theory. In particular, we show that through two loops, the four-particle amplitude in full N=4 SYM has only logarithmic ...... singularities and is free of any poles at infinity—properties closely related to uniform transcendentality and the UV finiteness of the theory. We also briefly comment on implications for maximal (N=8) supergravity theory (SUGRA)....
Nuclear capture at rest of Ξ hyperons
Aoki, S.; Bahk, S. Y.; Chung, S. H.; Funahashi, H.; Hahn, C. H.; Hanabata, M.; Hara, T.; Hirata, S.; Hoshino, K.; Ieiri, M.; Iijima, T.; Imai, K.; Itow, Y.; Jin-ya, T.; Kazuno, M.; Kim, C. O.; Kim, J. Y.; Kim, S. H.; Kodama, K.; Kuze, T.; Maeda, Y.; Masaike, A.; Masuoka, A.; Matsuda, Y.; Matsui, A.; Nagase, Y.; Nagoshi, C.; Nakamura, M.; Nakanishi, S.; Nakano, T.; Nakazawa, K.; Niwa, K.; Oda, H.; Okabe, H.; Ono, S.; Ozaki, R.; Park, B. D.; Park, I. G.; Sakai, K.; Sasaki, T.; Sato, Y.; Shibuya, H.; Shimizu, H. M.; Song, J. S.; Sugimoto, M.; Tajima, H.; Takahashi, H.; Takashima, R.; Takeutchi, F.; Tanaka, K. H.; Teranaka, M.; Tezuka, I.; Togawa, H.; Tsunemi, T.; Ukai, M.; Ushida, N.; Watanabe, T.; Yasuda, N.; Yokota, J.; Yoon, C. S.; KEK E176 Collaboration
2009-09-01
An emulsion-counter hybrid experiment (KEK E176) was carried out to search for double strangeness systems such as double- Λ hypernuclei and H-dibaryons. More than 10% of Ξ hyperons produced in the (K -, K +) reaction were brought to rest in the nuclear emulsion. We have obtained 98 candidate events of nuclear capture at rest of Ξ hyperons which are described in this report. Among those, four events were identified as sequential weak decay of double- Λ hypernuclei. The binding energies of Ξ-( 12C, 14N and 16O) states have been estimated for two events which emit twin single- Λ hypernuclei back to back from the capture point. The Σp decay vertex of an H-dibaryon was searched for near the capture point and no evidence was observed. Upper limits for the branching ratio of H emission are 5-10% for a lifetime less than 0.1 ns at the 90% confidence level. The trapping probabilities of single and double strangeness to a nuclear fragment following Ξ capture at rest have been studied.
Adam, J; Tater, M; Truhlik, E; Epelbaum, E; Machleidt, R; Ricci, P
2011-01-01
The doublet capture rate of the negative muon capture in deuterium is calculated employing the nuclear wave functions generated from accurate nucleon-nucleon potentials constructed at next-to-next-to-next-to-leading order of heavy-baryon chiral perturbation theory and the weak meson exchange current operator derived within the same formalism. All but one of the low-energy constants that enter the calculation were fixed from pion-nucleon and nucleon-nucleon scattering data. The low-energy constant d^R (c_D), which cannot be determined from the purely two-nucleon data, was extracted recently from the triton beta-decay and the binding energies of the three-nucleon systems. The calculated values of the doublet capture rates show a rather large spread for the used values of the d^R. Precise measurement of the doublet capture rate in the future will not only help to constrain the value of d^R, but also provide a highly nontrivial test of the nuclear chiral EFT framework. Besides, the precise knowledge of the consta...
Analytical solution and optimal design for galloping-based piezoelectric energy harvesters
Tan, T.; Yan, Z.
2016-12-01
The performance of the galloping-based piezoelectric energy harvester is usually investigated numerically. Instead of performing case studies by numerical simulations, analytical solutions of the nonlinear distributed parameter model are derived to capture the intrinsic effects of the physical parameters on the performance of such energy harvesters. The analytical solutions are confirmed with the numerical solutions. Optimal performance of such energy harvesters is therefore revealed theoretically. The electric damping due to the electromechanical coupling is defined. The design at the optimal electrical damping with smaller onset speed to galloping, higher harvested power, and acceptable tip displacement is superior than the design at the maximal electrical damping, as long as the optimal electrical damping can be achieved. Otherwise, the design at the maximal electrical damping should be then adopted. As the wind speed and aerodynamic empirical coefficients increase, the tip displacement and harvested power increase. This study provides a theoretical design and optimization procedure for galloping-based piezoelectric energy harvesters.
Maximizing Lifetime of Wireless Sensor Networks with Mobile Sink Nodes
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.
Load Mitigation and Optimal Power Capture for Variable Speed Wind Turbine in Region 2
Saravanakumar Rajendran
2015-01-01
Full Text Available This paper proposes the two nonlinear controllers for variable speed wind turbine (VSWT operating at below rated wind speed. The objective of the controller is to maximize the energy capture from the wind with reduced oscillation on the drive train. The conventional controllers such as aerodynamic torque feedforward (ATF and indirect speed control (ISC are adapted initially, which introduce more power loss, and the dynamic aspects of WT are not considered. In order to overcome the above drawbacks, modified nonlinear static state with feedback estimator (MNSSFE and terminal sliding mode controller (TSMC based on Modified Newton Raphson (MNR wind speed estimator are proposed. The proposed controllers are simulated with nonlinear FAST (fatigue, aerodynamics, structures, and turbulence WT dynamic simulation for different mean wind speeds at below rated wind speed. The frequency analysis of the drive train torque is done by taking the power spectral density (PSD of low speed shaft torque. From the result, it is found that a trade-off is to be maintained between the transient load on the drive train and maximum power capture.
Light Meson Physics from Maximally Twisted Mass Lattice QCD
Baron, R; Dimopoulos, P; Farchioni, F; Frezzotti, R; Gimenez, V; Herdoiza, G; Jansen, K; Lubicz, V; Michael, C; Muenster, G; Palao, D; Rossi, G C; Scorzato, L; Shindler, A; Simula, S; Sudmann, T; Urbach, C; Wenger, U
2009-01-01
We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for two mass-degenerate quark flavours. By employing four values of the lattice spacing, spatial lattice extents ranging from 2.0 fm to 2.5 fm and pseudo scalar masses in the range 280 MeV to 650 MeV we control the major systematic effects of our calculation. This enables us to confront our data with chiral perturbation theory and extract low energy constants of the effective chiral Lagrangian and derived quantities, such as the light quark mass, with high precision.
Arole, S; Gorringe, T P; Hasinoff, M D; Kovash, M A; Kuzmin, V; Moftah, B A; Sedlar, R; Stocki, T J; Tetereva, T
2002-01-01
We report measurements of $\\gamma$--ray spectra from muon capture on $^{35}$Cl. For the allowed Gamow--Teller transitions to the $^{35}$S$(2939, 3/2^+)$ state and the $^{35}$S$(3421, 5/2^+)$ state we obtained their capture rates, hyperfine dependences and $\\gamma$--$\
Cycle-maximal triangle-free graphs
Durocher, Stephane; Gunderson, David S.; Li, Pak Ching;
2015-01-01
Abstract We conjecture that the balanced complete bipartite graph K ⌊ n / 2 ⌋ , ⌈ n / 2 ⌉ contains more cycles than any other n -vertex triangle-free graph, and we make some progress toward proving this. We give equivalent conditions for cycle-maximal triangle-free graphs; show bounds...
Gradient dynamics and entropy production maximization
Janečka, Adam
2016-01-01
Gradient dynamics describes irreversible evolution by means of a dissipation potential, which leads to several advantageous features like Maxwell--Onsager relations, distinguishing between thermodynamic forces and fluxes or geometrical interpretation of the dynamics. Entropy production maximization is a powerful tool for predicting constitutive relations in engineering. In this paper, both approaches are compared and their shortcomings and advantages are discussed.
Robust Utility Maximization Under Convex Portfolio Constraints
Matoussi, Anis, E-mail: anis.matoussi@univ-lemans.fr [Université du Maine, Risk and Insurance institut of Le Mans Laboratoire Manceau de Mathématiques (France); Mezghani, Hanen, E-mail: hanen.mezghani@lamsin.rnu.tn; Mnif, Mohamed, E-mail: mohamed.mnif@enit.rnu.tn [University of Tunis El Manar, Laboratoire de Modélisation Mathématique et Numérique dans les Sciences de l’Ingénieur, ENIT (Tunisia)
2015-04-15
We study a robust maximization problem from terminal wealth and consumption under a convex constraints on the portfolio. We state the existence and the uniqueness of the consumption–investment strategy by studying the associated quadratic backward stochastic differential equation. We characterize the optimal control by using the duality method and deriving a dynamic maximum principle.
Maximizing the Motivated Mind for Emergent Giftedness.
Rea, Dan
2001-01-01
This article explains how the theory of the motivated mind conceptualizes the productive interaction of intelligence, creativity, and achievement motivation and how this theory can help educators to maximize students' emergent potential for giftedness. It discusses the integration of cold-order thinking and hot-chaotic thinking into fluid-adaptive…
The Winning Edge: Maximizing Success in College.
Schmitt, David E.
This book offers college students ideas on how to maximize their success in college by examining the personal management techniques a student needs to succeed. Chapters are as follows: "Getting and Staying Motivated"; "Setting Goals and Tapping Your Resources"; "Conquering Time"; "Think Yourself to College Success"; "Understanding and Remembering…
MAXIMAL ELEMENTS AND EQUILIBRIUM OF ABSTRACT ECONOMY
刘心歌; 蔡海涛
2001-01-01
An existence theorem of maximal elements for a new type of preference correspondences which are Qθ-majorized is given. Then some existence theorems of equilibrium for abstract economy and qualitative game in which the constraint or preference correspondences are Qθ-majorized are obtained in locally convex topological vector spaces.
DNA solution of the maximal clique problem.
Ouyang, Q; Kaplan, P D; Liu, S; Libchaber, A
1997-10-17
The maximal clique problem has been solved by means of molecular biology techniques. A pool of DNA molecules corresponding to the total ensemble of six-vertex cliques was built, followed by a series of selection processes. The algorithm is highly parallel and has satisfactory fidelity. This work represents further evidence for the ability of DNA computing to solve NP-complete search problems.
Maximizing Resource Utilization in Video Streaming Systems
Alsmirat, Mohammad Abdullah
2013-01-01
Video streaming has recently grown dramatically in popularity over the Internet, Cable TV, and wire-less networks. Because of the resource demanding nature of video streaming applications, maximizing resource utilization in any video streaming system is a key factor to increase the scalability and decrease the cost of the system. Resources to…
Maximizing throughput in an automated test system
朱君
2007-01-01
@@ Overview This guide is collection of whitepapers designed to help you develop test systems that lower your cost, increase your test throughput, and can scale with future requirements. This whitepaper provides strategies for maximizing system throughput. To download the complete developers guide (120 pages), visit ni. com/automatedtest.
The gaugings of maximal D=6 supergravity
Bergshoeff, E.; Samtleben, H.; Sezgin, E.
2008-01-01
We construct the most general gaugings of the maximal D = 6 supergravity. The theory is ( 2, 2) supersymmetric, and possesses an on-shell SO( 5, 5) duality symmetry which plays a key role in determining its couplings. The field content includes 16 vector fields that carry a chiral spinor representat
WEIGHTED BOUNDEDNESS OF A ROUGH MAXIMAL OPERATOR
无
2000-01-01
In this note the authors give the weighted Lp-boundedness fora class of maximal singular integral operators with rough kernel.The result in this note is an improvement and extension ofthe result obtained by Chen and Lin in 1990.
Maximizing the Range of a Projectile.
Brown, Ronald A.
1992-01-01
Discusses solutions to the problem of maximizing the range of a projectile. Presents three references that solve the problem with and without the use of calculus. Offers a fourth solution suitable for introductory physics courses that relies more on trigonometry and the geometry of the problem. (MDH)
Ehrenfest's Lottery--Time and Entropy Maximization
Ashbaugh, Henry S.
2010-01-01
Successful teaching of the Second Law of Thermodynamics suffers from limited simple examples linking equilibrium to entropy maximization. I describe a thought experiment connecting entropy to a lottery that mixes marbles amongst a collection of urns. This mixing obeys diffusion-like dynamics. Equilibrium is achieved when the marble distribution is…
Testing maximality in muon neutrino flavor mixing
Choubey, S; Choubey, Sandhya; Roy, Probir
2003-01-01
The small difference between the survival probabilities of muon neutrino and antineutrino beams, traveling through earth matter in a long baseline experiment such as MINOS, is shown to be an important measure of any possible deviation from maximality in the flavor mixing of those states.
Average utility maximization: A preference foundation
A.V. Kothiyal (Amit); V. Spinu (Vitalie); P.P. Wakker (Peter)
2014-01-01
textabstractThis paper provides necessary and sufficient preference conditions for average utility maximization over sequences of variable length. We obtain full generality by using a new algebraic technique that exploits the richness structure naturally provided by the variable length of the sequen
On the Hardy-Littlewood maximal theorem
Shinji Yamashita
1982-01-01
Full Text Available The Hardy-Littlewood maximal theorem is extended to functions of class PL in the sense of E. F. Beckenbach and T. Radó, with a more precise expression of the absolute constant in the inequality. As applications we deduce some results on hyperbolic Hardy classes in terms of the non-Euclidean hyperbolic distance in the unit disk.
Maximal Cartel Pricing and Leniency Programs
Houba, H.E.D.; Motchenkova, E.; Wen, Q.
2008-01-01
For a general class of oligopoly models with price competition, we analyze the impact of ex-ante leniency programs in antitrust regulation on the endogenous maximal-sustainable cartel price. This impact depends upon industry characteristics including its cartel culture. Our analysis disentangles the
How to Generate Good Profit Maximization Problems
Davis, Lewis
2014-01-01
In this article, the author considers the merits of two classes of profit maximization problems: those involving perfectly competitive firms with quadratic and cubic cost functions. While relatively easy to develop and solve, problems based on quadratic cost functions are too simple to address a number of important issues, such as the use of…
Ehrenfest's Lottery--Time and Entropy Maximization
Ashbaugh, Henry S.
2010-01-01
Successful teaching of the Second Law of Thermodynamics suffers from limited simple examples linking equilibrium to entropy maximization. I describe a thought experiment connecting entropy to a lottery that mixes marbles amongst a collection of urns. This mixing obeys diffusion-like dynamics. Equilibrium is achieved when the marble distribution is…
Maximally entangled mixed states made easy
Aiello, A; Voigt, D; Woerdman, J P
2006-01-01
We show that, contrarily to a recent claim [M. Ziman and V. Bu\\v{z}ek, Phys. Rev. A. \\textbf{72}, 052325 (2005)], it is possible to achieve maximally entangled mixed states of two qubits from the singlet state via the action of local nonunital quantum channels. Moreover, we present a simple, feasible linear optical implementation of one of such channels.
Maximizing Resource Utilization in Video Streaming Systems
Alsmirat, Mohammad Abdullah
2013-01-01
Video streaming has recently grown dramatically in popularity over the Internet, Cable TV, and wire-less networks. Because of the resource demanding nature of video streaming applications, maximizing resource utilization in any video streaming system is a key factor to increase the scalability and decrease the cost of the system. Resources to…
Maximizing scientific knowledge from randomized clinical trials
Gustafsson, Finn; Atar, Dan; Pitt, Bertram
2010-01-01
Trialists have an ethical and financial responsibility to plan and conduct clinical trials in a manner that will maximize the scientific knowledge gained from the trial. However, the amount of scientific information generated by randomized clinical trials in cardiovascular medicine is highly...
Maximal Heat Generation in Nanoscale Systems
ZHOU Li-Ling; LI Shu-Shen; ZENG Zhao-Yang
2009-01-01
We investigate the heat generation in a nanoscale system coupled to normal leads and find that it is maximal when the average occupation of the electrons in the nanoscale system is 0.5,no matter what mechanism induces the heat generation.
Understanding violations of Gricean maxims in preschoolers and adults.
Okanda, Mako; Asada, Kosuke; Moriguchi, Yusuke; Itakura, Shoji
2015-01-01
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.
Understanding Violations of Gricean Maxims in Preschoolers and Adults
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.
Materials For Gas Capture, Methods Of Making Materials For Gas Capture, And Methods Of Capturing Gas
Polshettiwar, Vivek
2013-06-20
In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure, in one aspect, relate to materials that can be used for gas (e.g., CO.sub.2) capture, methods of making materials, methods of capturing gas (e.g., CO.sub.2), and the like, and the like.
Bicarbonate produced from carbon capture for algae culture.
Chi, Zhanyou; O'Fallon, James V; Chen, Shulin
2011-11-01
Using captured CO(2) to grow microalgae is limited by the high cost of CO(2) capture and transportation, as well as significant CO(2) loss during algae culture. Moreover, algae grow poorly at night, but CO(2) cannot be temporarily stored until sunrise. To address these challenges, we discuss a process where CO(2) is captured as bicarbonate and used as feedstock for algae culture, and the carbonate regenerated by the culture process is used as an absorbent to capture more CO(2). This process would significantly reduce carbon capture costs because it does not require additional energy for carbonate regeneration. Furthermore, not only would transport of the aqueous bicarbonate solution cost less than for that of compressed CO(2), but using bicarbonate would also provide a superior alternative for CO(2) delivery to an algae culture system.
Neutron Capture Experiments Using the DANCE Array at Los Alamos
Dashdorj, D.; Mitchell, G. E.; Baramsai, B.; Chyzh, A.; Walker, C.; Agvaanluvsan, U.; Becker, J. A.; Parker, W.; Sleaford, B.; Wu, C. Y.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wouters, J. M.; Krtička, M.; Bečvář, F.
2009-03-01
The Detector for Advanced Neutron Capture Experiments (DANCE) is designed for neutron capture measurements on very small and/or radioactive targets. The DANCE array of 160 BaF2 scintillation detectors is located at the Lujan Center at the Los Alamos Neutron Science Center (LANSCE). Accurate measurements of neutron capture data are important for many current applications as well as for basic understanding of neutron capture. The gamma rays following neutron capture reactions have been studied by the time-of-flight technique using the DANCE array. The high granularity of the array allows measurements of the gamma-ray multiplicity. The gamma-ray multiplicities and energy spectra for different multiplicities can be measured and analyzed for spin and parity determination of the resolved resonances.
Corrections to nucleon capture cross sections computed in truncated Hilbert spaces
Acharya, B; Odell, D; Papenbrock, T; Platter, L
2016-01-01
Nucleon capture cross sections enter various astrophysical processes. The measurement of proton capture on nuclei at astrophysically relevant low energies is a challenge, and the precise theoretical computation in this long-wavelength regime requires us to understand the corrections due to finite Hilbert spaces. We derive extrapolation formulas that relate the infrared regularized capture amplitudes to the infinite basis limit and demonstrate their efficacy for proton-proton fusion. Our results are thus relevant to current calculations of few-body capture reactions such as proton-proton fusion or proton capture on the deuteron, and also open the way for a more precise understanding of nucleon capture on heavier nuclei.
Basic Research Needs for Carbon Capture: Beyond 2020
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
Study of thermal neutron capture in /sup 23/Na
Zhang Ming; Shi Zongren; Zeng Xiantang; Li Guohua; Ding Dazhao
1987-11-01
Energies and intensities of 117 gamma-rays produced by the capture of thermal neutron in /sup 23/Na are measured by using a single Ge(Li) detector and a pair spectrometer. 107 gamma-rays are placed in the decay scheme consisting of 35 levels. The neutron binding energy is found to be 6959.51 (21) keV. The parameters of /sup 24/Na energy level density are determined with the Back-Shift Fermi Gas Model. The /sup 23/Na(n, ..gamma..)/sup 24/Na reaction is mainly a statistical process from the resonance capture of 2.85 keV state.
Study of thermal neutron capture in /sup 23/Na
Zhang Ming; Shi Zongren; Zeng Xiantang; Li Guohua; Ding Dazhao
1989-04-01
Energies and intensities of 117 gamma-rays produced by the capture of thermal neutrons in /sup 23/Na are measured by using a single Ge(Li) detector and a pair spectrometer. 107 gamma-rays are placed in a decay scheme consisting of 35 levels. The neutron binding energy is found to be 6959.51 (21) keV. The parameters of /sup 24/Na energy-level density are determined with the Back-Shift Fermi Gas Model. The /sup 23/Na(/ital n/,..gamma..) /sup 24/Na reaction is mainly a statistical process from the resonance capture of the 2.85 keV state.
Provenance Datasets Highlighting Capture Disparities
2014-01-01
the Web pages of the universities and institutes.1 Notes are made and links pasted in a variety of formats. Files are saved on a shared drive. When...institutions/ 3. Capture Methods There are several capture methods that are available for use [4]: • Manual capture. • Scraping of logs or...the high-level user desktop. Save links App: Word, SharePoint User: Alice Web Data Web Data Web Data Web Data Web Data Web Data Notes.txt Create
Li, Xueliang; Gutman, Ivan
2012-01-01
This book is about graph energy. The authors have included many of the important results on graph energy, such as the complete solution to the conjecture on maximal energy of unicyclic graphs, the Wagner-Heuberger's result on the energy of trees, the energy of random graphs or the approach to energy using singular values. It contains an extensive coverage of recent results and a gradual development of topics and the inclusion of complete proofs from most of the important recent results in the area. The latter fact makes it a valuable reference for researchers looking to get into the field of g