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1

Enhanced Kerr electro-optic nonlinearity through cascaded Pockels effects  

E-Print Network [OSTI]

We demonstrated a large enhancement of Kerr electro-optic nonlinearity through cascaded Pockels effects in a domain inversion ferroelectric crystal. We designed a structure that can implement the cascaded Pockels effects and second-harmonic generation simultaneously. The energy coupling between the fundamental lights of different polarizations led to a large nonlinear phase shift, and thus an effective electro-optic nonlinear refractive index. The effective nonlinearity can be either positive or negative, causing the second-harmonic spectra to move towards the coupling center, which in turn, offered us a way to measure the effective electro-optic nonlinear refractive index. The corresponding enhanced Kerr electro-optic nonlinearity is more than three orders of magnitude higher than the intrinsic value. These results open a door to manipulate the nonlinear phase by applying external electric field instead of light intensity in noncentrosymmetric crystals.

Li, Guang-Zhen; Jiang, Hao-Wei; Chen, Xian-Feng

2015-01-01T23:59:59.000Z

2

Recent results from parton cascade and microscopic transport  

E-Print Network [OSTI]

Parton cascade is a microscopic transport approach for the study of the space-time evolution of the Quark-Gluon Plasma produced in relativistic heavy ion collisions and its experimental manifestations. In the following, parton cascade calculations on elliptic flow and thermalization will be discussed. Dynamical evolution is shown to be important for the production of elliptic flow including the scaling and the breaking of the scaling of elliptic flow. The degree of thermalization is estimated using both an elastic parton cascade and a radiative transport model. A longitudinal to transverse pressure ratio, $P_L/P_T\\approx 0.8$, is shown to be expected in the central cell in central collisions. This provides information on viscous corrections to the ideal hydrodynamical approach.

Bin Zhang

2008-09-02T23:59:59.000Z

3

E-Print Network 3.0 - acid cascade enzymes Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Biology and Medicine 38 Computational Modelling of Kinase Signalling Cascades David Gilbert, Monika Heiner, Rainer Breitling, and Richard Orton Summary: of Kinase Signalling...

4

Numerical calculations of cosmic ray cascade in the Earth's atmosphere Results for nucleon spectra  

E-Print Network [OSTI]

such as production of cosmogenic nuc- lides, radiation dosimetry and single event upsets in the microelec- tronics [1 in the atmosphere. Some of the particles produced in the cascade can reach the Earth's surface and induce nuclear

5

Assessing Water Deprivation at the Sub-river Basin Scale in LCA Integrating Downstream Cascade Effects  

Science Journals Connector (OSTI)

Assessing Water Deprivation at the Sub-river Basin Scale in LCA Integrating Downstream Cascade Effects ... Although these indicators represent a great step forward in the assessment of water-use-related impacts in LCA, significant challenges still remain in improving their accuracy and relevance. ...

Philippe Loubet; Philippe Roux; Montserrat Núñez; Gilles Belaud; Véronique Bellon-Maurel

2013-11-20T23:59:59.000Z

6

Near-infrared induced optical quenching effects on mid-infrared quantum cascade lasers  

SciTech Connect (OSTI)

In space communications, atmospheric absorption and Rayleigh scattering are the dominant channel impairments. Transmission using mid-infrared (MIR) wavelengths offers the benefits of lower loss and less scintillation effects. In this work, we report the telecom wavelengths (1.55??m and 1.3??m) induced optical quenching effects on MIR quantum cascade lasers (QCLs), when QCLs are operated well above their thresholds. The QCL output power can be near 100% quenched using 20?mW of near-infrared (NIR) power, and the quenching effect depends on the input NIR intensity as well as wavelength. Time resolved measurement was conducted to explore the quenching mechanism. The measured recovery time is around 14?ns, which indicates that NIR generated electron-hole pairs may play a key role in the quenching process. The photocarrier created local field and band bending can effectively deteriorate the dipole transition matrix element and quench the QCL. As a result, MIR QCLs can be used as an optical modulator and switch controlled by NIR lasers. They can also be used as “converters” to convert telecom optical signals into MIR optical signals.

Guo, Dingkai, E-mail: dingk1@umbc.edu; Talukder, Muhammad Anisuzzaman; Chen, Xing [Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Cai, Hong [Center of Advanced Studies in Photonics Research (CASPR), University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Johnson, Anthony M.; Choa, Fow-Sen [Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Center of Advanced Studies in Photonics Research (CASPR), University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (United States); Khurgin, Jacob B. [Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

2014-06-23T23:59:59.000Z

7

Nonlinear effects in collision cascades and high energy shock waves during ta-C:H growth  

SciTech Connect (OSTI)

The surface topography of hydrogenated tetrahedral amorphous carbon (ta-C:H) is critical for various applications such as microelectromechanical devices, magnetic and optical storage devices, and medical implants. The surface topography of ta-C:H films deposited by distributed electron cyclotron resonance plasma from C{sub 2}H{sub 2} gas precursor was investigated. The effects of pressure, together with ion flux and energy, are studied by atomic force microscopy in relation to the structural evolution of the films. The results are compared with the predictions of the Edward-Wilkinson model [Proc. R. Soc. London, Ser. A 44, 1039 (1966)] recently proposed to account for ta-C:H growth and with previous interpretations based on hypersonic shock waves. The random hillocks observed on the smooth surfaces of ta-C:H films deposited at high pressure are thought to result from the interference of high energy shock waves triggered by C{sub 4}H{sub x}{sup +} ions that produce overlapping collision cascades and induce nonlinear effects.

Piazza, F.; Resto, O.; Morell, G. [Department of Physics, University of Puerto Rico, P.O. Box 23343, San Juan, 00931 (Puerto Rico)

2007-07-01T23:59:59.000Z

8

MATCASC: A tool to analyse cascading line outages in power grids  

E-Print Network [OSTI]

Blackouts in power grids typically result from cascading failures. The key importance of the electric power grid to society encourages further research into sustaining power system reliability and developing new methods to manage the risks of cascading blackouts. Adequate software tools are required to better analyze, understand, and assess the consequences of the cascading failures. This paper presents MATCASC, an open source MATLAB based tool to analyse cascading failures in power grids. Cascading effects due to line overload outages are considered. The applicability of the MATCASC tool is demonstrated by assessing the robustness of IEEE test systems and real-world power grids with respect to cascading failures.

Koç, Yakup; Araujo, Nuno A M; Warnier, Martijn

2013-01-01T23:59:59.000Z

9

Aeolian tones of a plate cascade  

Science Journals Connector (OSTI)

A model for the aeroacoustic resonance effects (aeolian tones) excited around a plate cascade in a gas flow is suggested. Methods of calculating the frequencies of natural acoustic oscillations near the cascade a...

S. V. Sukhinin

10

Effects of temporal correlations on cascades: Threshold models on temporal networks  

Science Journals Connector (OSTI)

A person's decision to adopt an idea or product is often driven by the decisions of peers, mediated through a network of social ties. A common way of modeling adoption dynamics is to use threshold models, where a node may become an adopter given a high enough rate of contacts with adopted neighbors. We study the dynamics of threshold models that take both the network topology and the timings of contacts into account, using empirical contact sequences as substrates. The models are designed such that adoption is driven by the number of contacts with different adopted neighbors within a chosen time. We find that while some networks support cascades leading to network-level adoption, some do not: the propagation of adoption depends on several factors from the frequency of contacts to burstiness and timing correlations of contact sequences. More specifically, burstiness is seen to suppress cascade sizes when compared to randomized contact timings, while timing correlations between contacts on adjacent links facilitate cascades.

Ville-Pekka Backlund; Jari Saramäki; Raj Kumar Pan

2014-06-26T23:59:59.000Z

11

CASCADE OPTIMIZATION AND CONTROL OF BATCH REACTORS  

E-Print Network [OSTI]

CASCADE OPTIMIZATION AND CONTROL OF BATCH REACTORS Xiangming Hua, Sohrab Rohani and Arthur Jutan ajutan@uwo.ca Abstract: In this study, a cascade closed-loop optimization and control strategy for batch reactor. Using model reduction a cascade system is developed, which can effectively combine optimization

Jutan, Arthur

12

Comparative performance evaluation of cascaded air-source hydronic heat pumps  

Science Journals Connector (OSTI)

Abstract The results are reported of an investigation of the effects of cascading air-source heat pumps on performance for hydronic residential systems. Three heat pump systems are modeled as single-stage, single-refrigerant cascaded, and two-refrigerant cascaded. Energy and exergy analyses are performed, and a comparative performance analysis is carried out, considering energy efficiency, refrigerant mass flow rates, evaporator pressure, exergy efficiency, and several other criteria. Three sets of source and supply temperatures, representing different climates and different water sink systems (low, medium and high temperature), are used to provide more comprehensive behavior assessments of the systems. Additionally, the optimum intermediate pressure of the cascaded systems for all working temperature pairs is found for the highest energetic COP and exergetic COP. Compared to a single stage heat pump, cascading improves the overall energy efficiency of the system for low-ambient temperatures, but not for high-ambient temperatures. Although this improvement is minor, the exergetic COP is increased by 67% for the single refrigerant cascaded system and 70% for a two-refrigerant cascaded system, at low ambient temperatures. Using refrigerant R404A in the low-pressure cycle marginally improves the energetic COP of the cascaded heat pump, but increases the evaporator working pressure, making it possible to use smaller compressors. However, the overall refrigerant mass flow rates increase with cascading. The two cascaded systems have higher exergy destructions (by almost four times) compared to the single stage system, mainly due to having more components, including an intermediate heat exchanger. Also, cascading shifts the major exergy destruction centers from the compressors and expansion valves to the evaporators. A comparison of cascaded and single-stage heat pumps shows that the exergy analysis results exhibit a different trend than energy analysis results with source and supply temperatures, highlighting the advantages of exergy methods in determining if cascading is appropriate for a given application.

R. Soltani; I. Dincer; M.A. Rosen

2015-01-01T23:59:59.000Z

13

Cascades Geothermal Region | Open Energy Information  

Open Energy Info (EERE)

Cascades Geothermal Region Cascades Geothermal Region Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Cascades Geothermal Region Details Areas (21) Power Plants (0) Projects (3) Techniques (5) Map: {{{Name}}} The Cascade Range is part of a vast mountain chain that extends from British Columbia to northern California and has been volcanically active for ~ 40 million years as a result of the convergence of the of the Juan de Fuca and Pacific plates. Two physiographic sub-provinces make up the Cascade Range; the Western Cascades and the High Cascades on the east. Middle Eocene to early Pliocene (40 - 5 million years) thick mafic lava flows, primarily of andesitic composition are associated with ash flows, tuffs, and silicic intrusive bodies and stocks that decrease in age eastward to the High Cascades. Miocene to Holocene volcanic rocks make up

14

Cascades Geothermal Region | Open Energy Information  

Open Energy Info (EERE)

Cascades Geothermal Region Cascades Geothermal Region (Redirected from Cascades) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Cascades Geothermal Region Details Areas (21) Power Plants (0) Projects (3) Techniques (5) Map: {{{Name}}} The Cascade Range is part of a vast mountain chain that extends from British Columbia to northern California and has been volcanically active for ~ 40 million years as a result of the convergence of the of the Juan de Fuca and Pacific plates. Two physiographic sub-provinces make up the Cascade Range; the Western Cascades and the High Cascades on the east. Middle Eocene to early Pliocene (40 - 5 million years) thick mafic lava flows, primarily of andesitic composition are associated with ash flows, tuffs, and silicic intrusive bodies and stocks that decrease in age

15

Effect of Doppler broadening on Autler-Townes splitting in the molecular cascade excitation scheme  

Science Journals Connector (OSTI)

Theoretical analysis of the Autler-Townes splitting pattern in a three-level cascade excitation of a Doppler-broadened sample reveals that the observed Autler-Townes splitting is not only a function of the coupling-laser Rabi frequency, as in the homogeneously broadened case, but can also strongly depend on the wavenumber ratio of the coupling and probe lasers. Utilizing a steady-state density matrix formalism, we derive exact expressions for the populations of the intermediate and upper levels for a homogeneously broadened system. In the limit of a weak probe field, analytical expressions for Doppler-broadened excitation spectra from the intermediate and upper levels are derived. Using these expressions, we investigate the critical role of Doppler broadening on the observation of Autler-Townes splitting and its asymptotic behavior as a function of the coupling Rabi frequency for counterpropagating and copropagating configurations for different wavenumber ratios of the lasers.

E. Ahmed and A. M. Lyyra

2007-11-09T23:59:59.000Z

16

Terahertz quantum cascade lasers  

Science Journals Connector (OSTI)

...Michael Pepper Terahertz quantum cascade lasers Jerome Faist 1 Lassaad Ajili...developments in terahertz quantum cascade lasers are reviewed. Structures...magnetic confinement| Terahertz quantum cascade lasers. | Recent developments in...

2004-01-01T23:59:59.000Z

17

Improving the aerodynamic efficiency of blade profile cascade used in a cooled turbine  

Science Journals Connector (OSTI)

Good effect from using rotor blade cascades, the pressure side’s profile of which has a bend near the trailing edge at an angle of no larger than 15°, is confirmed from the results of experimental studies.

B. I. Mamaev; M. R. Valeev

2010-09-01T23:59:59.000Z

18

Strain-balanced quantum cascade lasers: influence of growth temperature on interface roughness and laser performance  

Science Journals Connector (OSTI)

Effect of substrate temperature on the performances of quantum cascade lasers operating at 4.6um is presented. Using a density matrix model results for different growth temperatures...

Bismuto, Alfredo; Terazzi, Romain; Beck, Mattias; Faist, Jerome

19

Cascading and local-field effects in non-linear optics revisited: A quantum-field picture based on exchange of photons  

SciTech Connect (OSTI)

The semi-classical theory of radiation-matter coupling misses local-field effects that may alter the pulse time-ordering and cascading that leads to the generation of new signals. These are then introduced macroscopically by solving Maxwell's equations. This procedure is convenient and intuitive but ad hoc. We show that both effects emerge naturally by including coupling to quantum modes of the radiation field that are initially in the vacuum state to second order. This approach is systematic and suggests a more general class of corrections that only arise in a QED framework. In the semi-classical theory, which only includes classical field modes, the susceptibility of a collection of N non-interacting molecules is additive and scales as N. Second-order coupling to a vacuum mode generates an effective retarded interaction that leads to cascading and local field effects both of which scale as N{sup 2}.

Bennett, Kochise, E-mail: kcbennet@uci.edu; Mukamel, Shaul, E-mail: smukamel@uci.edu [Chemistry Department, University of California, Irvine, California 92697-2025 (United States)] [Chemistry Department, University of California, Irvine, California 92697-2025 (United States)

2014-01-28T23:59:59.000Z

20

A relativistic cascade for heavy ion collisions  

SciTech Connect (OSTI)

Au on Au collisions at the BNL/AGS (11.6 GeV-A/c) are expected to produce a short-lived state of matter at high baryon density. If the baryons reach sufficiently high density, they may produce a quark-gluon plasma (QGP). The signals from a QGP phase may be difficult to distinguish from those of ordinary hadronic matter. The authors have constructed a relativistic cascade (ARC) for hadrons in an attempt to model the dynamics of ordinary hadronic matter in a heavy ion collision, in the hopes that deviations from the cascade results may indicate new physics. In this contribution the authors discuss the formation of high baryon density matter, and its effect on antiproton production.

Schlagel, T.J.; Pang, Y.; Kahana, S.H.

1994-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Definition: Cascading Outage | Open Energy Information  

Open Energy Info (EERE)

Cascading Outage Cascading Outage Jump to: navigation, search Dictionary.png Cascading Outage The uncontrolled successive loss of system elements triggered by an incident at any location. Cascading results in widespread electric service interruption that cannot be restrained from sequentially spreading beyond an area predetermined by studies.[1] View on Wikipedia Wikipedia Definition A cascading failure is a failure in a system of interconnected parts in which the failure of a part can trigger the failure of successive parts. Such a failure may happen in many types of systems, including power transmission, computer networking, finance and bridges. Cascading failures usually begin when one part of the system fails. When this happens, nearby nodes must then take up the slack for the failed component. This overloads

22

Lethal control of an apex predator has unintended cascading effects on forest mammal assemblages  

Science Journals Connector (OSTI)

...known about the dingo's ecological role in the forests of southeastern...continents suggest that dingoes ecological effects may be weaker or more...m intervals along unpaved vehicle tracks with washed sand spread...seated in a four-wheel drive vehicle visually scanned the habitat...

2014-01-01T23:59:59.000Z

23

MOLECULAR DYNAMICS SIMULATIONS OF DISPLACEMENT CASCADES IN MOLYBDENUM  

SciTech Connect (OSTI)

Molecular dynamics calculations have been employed to simulate displacement cascades in neutron irradiated Mo. A total of 90 simulations were conducted for PKA energies between 1 and 40 keV and temperatures from 298 to 923K. The results suggest very little effect of temperature on final defect count and configuration, but do display a temperature effect on peak defect generation prior to cascade collapse. Cascade efficiency, relative to the NRT model, is computed to lie between 1/4 and 1/3 in agreement with simulations performed on previous systems. There is a tendency for both interstitials and vacancies to cluster together following cascade collapse producing vacancy rich regions surrounded by interstitials. Although coming to rest in close proximity, the point defects comprising the clusters generally do not lie within the nearest neighbor positions of one another, except for the formation of dumbbell di-interstitials. Cascades produced at higher PKA energies (20 or 40 keV) exhibit the formation of subcascades.

Smith, Richard Whiting

2003-09-08T23:59:59.000Z

24

Superlattice cascade solar cell  

SciTech Connect (OSTI)

This paper reports progress toward realization of a new cascade solar cell structure whose chief advantages over other present concepts are: use of silicon for the substrate and low bandgap cell; avoidance of the necessity of lattice matching; and incorporation of a GaAs/GaP superlattice to enhance efficiency and provide a low-resistance connecting junction. Details of the design and operation of an OMCVD system for growing this structure are presented. Results of experiments to optimize layer thickness, compositional uniformity, and surface morphology are described.

Wanlass, M.W.; Blakeslee, A.E.

1982-09-01T23:59:59.000Z

25

Contingency Analysis of Cascading Line Outage Events  

SciTech Connect (OSTI)

As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.

Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

2011-03-01T23:59:59.000Z

26

Cascade Model of an Anomaly in Blazar Spectra at Very High Energy  

E-Print Network [OSTI]

It is well known that the effect of gamma-ray absorption on extragalactic background light (EBL) is weakly expressed in the spectra of some blazars. It is shown that a secondary component generated by electromagnetic cascades might considerably decrease the statistical significance of this anomaly. Observational results indicate the existence of the cascade component in the spectra of extragalactic gamma-ray sources, thus supporting the proposed model.

Dzhatdoev, Timur

2015-01-01T23:59:59.000Z

27

Engineering Light: Quantum Cascade Lasers  

ScienceCinema (OSTI)

Quantum cascade lasers are ideal for environmental sensing and medical diagnostic applications. Gmachl discusses how these lasers work, and their applications, including their use as chemical trace gas sensors. As examples of these applications, she briefly presents results from her field campaign at the Beijing Olympics, and ongoing campaigns in Texas, Maryland, and Ghana.

Claire Gmachl

2010-09-01T23:59:59.000Z

28

Multiperiod quantum-cascade nanoheterostructures: Epitaxy and diagnostics  

SciTech Connect (OSTI)

Advances in the production technology of multiperiod nanoheterostructures of quantum-cascade lasers with 60 cascades by molecular-beam epitaxy (MBE) on an industrial multiple-substrate MBE machine are discussed. The results obtained in studying the nanoheterostructures of quantum-cascade lasers by transmission electron microscopy, high-resolution X-ray diffraction analysis, and photoluminescence mapping are presented.

Egorov, A. Yu., E-mail: Anton@beam.ioffe.ru; Brunkov, P. N.; Nikitina, E. V.; Pirogov, E. V.; Sobolev, M. S.; Lazarenko, A. A. [Russian Academy of Sciences, St. Petersburg Academic University, Nanotechnology Research and Education Center (Russian Federation); Baidakova, M. V.; Kirilenko, D. A.; Konnikov, S. G. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

2014-12-15T23:59:59.000Z

29

Cascade Organic Solar Cells  

Science Journals Connector (OSTI)

Cascade Organic Solar Cells ... Multiple factors control the efficiency of organic solar cells, making it difficult to use single donor or acceptor materials to balance the, often opposing, material properties required to optimize device performance. ... We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C60/bathocuproine/Al. ...

Cody W. Schlenker; Vincent S. Barlier; Stephanie W. Chin; Matthew T. Whited; R. Eric McAnally; Stephen R. Forrest; Mark E. Thompson

2011-09-02T23:59:59.000Z

30

Terahertz Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We provide an overview of terahertz quantum cascade lasers based on resonant-phonon depopulation and metal-metal waveguides, including two-phonon resonant-phonon depopulation...

Williams, Benjamin; Kumar, Sushil; Qin, Qi; Lee, Alan Wei Min; Hu, Qing; Reno, John L; Wasilewski, Z R; Liu, H C

31

Sub-Doppler Spectra of Infrared Hyperfine Transitions of Nitric Oxide Using a Pulse Modulated Quantum Cascade Laser: Rapid Passage, Free Induction Decay and the AC Stark Effect  

SciTech Connect (OSTI)

Using a low power, rapid (nsec) pulse-modulated quantum cascade (QC) laser, collective coherent effects in the 5 {micro}m spectrum of nitric oxide have been demonstrated by the observation of sub-Doppler hyperfine splitting and also Autler-Townes splitting of Doppler broadened lines. For nitrous oxide, experiments and model calculations have demonstrated that two main effects occur with ulsemodulated (chirped) quantum cascade lasers: free induction decay signals, and signals induced by rapid passage during the laser chirp. In the open shell molecule, NO, in which both {Lambda}-doubling splitting and hyperfine structure occur, laser field-induced coupling between the hyperfine levels of the two {Lambda}-doublet components can induce a large AC Stark effect. This may be observed as sub-Doppler structure, field-induced splittings, or Autler-Townes splitting of a Doppler broadened line. These represent an extension of the types of behaviour observed in the closed shell molecule nitrous oxide, using the same apparatus, when probed with an 8 {micro}m QC laser.

Duxbury, Geoffrey; Kelly, James F.; Blake, Thomas A.; Langford, Nigel

2012-05-07T23:59:59.000Z

32

Terahertz quantum cascade lasers  

E-Print Network [OSTI]

The development of the terahertz frequency range has long been impeded by the relative dearth of compact, coherent radiation sources of reasonable power. This thesis details the development of quantum cascade lasers (QCLs) ...

Williams, Benjamin S. (Benjamin Stanford), 1974-

2003-01-01T23:59:59.000Z

33

Unsteady aerodynamic analysis of subsonic oscillating cascade  

SciTech Connect (OSTI)

This paper describes the development of the source-doublet-based potential paneling method for oscillating cascade unsteady aerodynamic load predictions. By using the integral influence coefficient method and by using the interblade phase angles, the unsteady loads on an oscillating cascade can be accurately predicted at a minimum cost. As the grids are placed only on the blade surfaces, the blades are allowed to vibrate without grid deformation problems. Four notable subsonic oscillating cascade test cases that cover most important parameters, e.g., blade geometry, interblade phase angle, flow coefficient, flow speed, frequency, etc., are studied in this paper. The agreement between the present solutions and other numerical/experimental results demonstrates the robustness of the present model. Applicability of the method for realistic compressible flow cascades is also discussed.

Chen, S.H.; Eastland, A.H.; Jackson, E.D. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.)

1994-07-01T23:59:59.000Z

34

Colliding cascades model for earthquake prediction  

E-Print Network [OSTI]

cascades: a direct cascade of loading, which is applied to the top (largest) ... on a direct cascade that would deliver energy from the largest ...... Forest fires: an.

2000-10-12T23:59:59.000Z

35

Rhodium-catalyzed epoxide-opening cascades toward brevisin and hemibrevetoxin B  

E-Print Network [OSTI]

CHAPTER I. Rhodium-Catalyzed Epoxide-Opening Cascades: Formal Synthesis of (-)-Brevisin [chemical formula inserted] [Rh(CO)?Cl]? was found to be an effective catalyst for endo-selective cyclizations and cascades of ...

Armbrust, Kurt W. (Kurt Willes)

2014-01-01T23:59:59.000Z

36

Soliton compression to high-quality few-cycle pulses by engineering cascaded quadratic nonlinearities  

E-Print Network [OSTI]

We propose an efficient approach to improve few-cycle soliton compression with cascaded quadratic nonlinearities by using an engineered multi-section structure of the nonlinear crystal. By exploiting engineering of the cascaded quadratic nonlinearities, in each section soliton compression with a low effective order is realized, and high-quality few-cycle pulses with large compression factors are feasible. Each subsequent section is designed so that the compressed pulse exiting the previous section experiences an overall effective self-defocusing cubic nonlinearity corresponding to a modest soliton order, which is kept larger than unity to ensure further compression. This is done by increasing the cascaded quadratic nonlinearity in the new section with an engineered reduced residual phase mismatch. The low soliton orders in each section ensure excellent pulse quality and high efficiency. Numerical results show that compressed pulses with less than three-cycle duration can be achieved even when the compression ...

Zeng, Xianglong; Zhou, Binbin; Bache, Morten

2012-01-01T23:59:59.000Z

37

Delay time calculation for dual-wavelength quantum cascade lasers  

SciTech Connect (OSTI)

In this paper, we calculate the turn-on delay (t{sub th}) and buildup (?t) times of a midinfrared quantum cascade laser operating simultaneously on two laser lines having a common upper level. The approach is based on the four-level rate equations model describing the variation of the electron number in the states and the photon number present within the cavity. We obtain simple analytical formulae for the turn-on delay and buildup times that determine the delay times and numerically apply our results to both the single and bimode states of a quantum cascade laser, in addition the effects of current injection on t{sub th} and ?t are explored.

Hamadou, A., E-mail: abd-hamado@yahoo.fr [Département des Sciences et Techniques, Faculté des Sciences et de la Technologie, Université de Bordj Bou Arreridj 34000 (Algeria); Laboratoire d’étude des surfaces et interfaces des matériaux solides (LESIMS), Sétif 19000 (Algeria); Lamari, S. [Laboratoire d’étude des surfaces et interfaces des matériaux solides (LESIMS), Sétif 19000 (Algeria); Département de Physique, Faculté des Sciences, Université Sétif 1, 19000 (Algeria); Thobel, J.-L. [Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), UMR 8520, Université Lille1, Avenue Poincaré, BP 60069, 59652 Villeneuve d'Ascq Cédex (France)

2013-11-28T23:59:59.000Z

38

Quantum dot cascade laser  

Science Journals Connector (OSTI)

We demonstrated an unambiguous quantum dot cascade laser based on InGaAs/GaAs/InAs/InAlAs heterostructure by making use of self-assembled quantum dots in the Stranski-Krastanow growth mode...??~?6.15 ?m and a bro...

Ning Zhuo; Feng Qi Liu; Jin Chuan Zhang; Li Jun Wang…

2014-03-01T23:59:59.000Z

39

Quantum Cascade Lasers: New Resonant Tunnelling Light Sources for the Mid-Infrared  

Science Journals Connector (OSTI)

15 October 1996 research-article Quantum Cascade Lasers: New Resonant Tunnelling Light Sources...Hutchinson A. Y. Cho Recent results on quantum cascade lasers are reviewed. In these quantum devices based on resonant tunnelling the...

1996-01-01T23:59:59.000Z

40

Classical Radiative Cascade in Antiproton Atoms  

SciTech Connect (OSTI)

An interrelation between radiative cascade transitions and annihilation rates in antiproton atoms is considered. The population of antiproton atom energy levels is described by a classical distribution function f(n,l), determining intensities of spectral lines in antiproton atoms. A strong dependence of spectral line intensities on the nuclear size is shown which could be used for the determination of effective nuclear radius.

Bureyeva, L. [Institute of Spectroscopy of the RAS, Troitsk, Moscow Reg., 142190 (Russian Federation); Lisitsa, V. [Nuclear Fusion Institute, Russian Research Center 'Kurchatov Institute' Moscow (Russian Federation); Putlitz, G. zu [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany)

2005-10-26T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Cascaded frequency doublers for broadband laser radiation  

SciTech Connect (OSTI)

A new scheme of a cascaded converter of the first harmonic of broadband cw laser radiation into the second harmonic (SH) with compensation for the group walk-off in cascades is proposed and investigated. The conditions under which high conversion coefficients of broadband ({approx}33 cm{sup -1}) single-mode fibre laser radiation with low peak power ({approx}300 W) into the SH are determined for frequency doublers based on the most promising LBO crystal. Conversion of cw radiation with an average power of 300 W and efficiency {eta} = 4.5 % into the SH is obtained in a single LBO crystal. Effect of coherent addition of SH radiation excited in different cascades is demonstrated for two- and three-stage schemes. The expected conversion efficiencies, calculated disregarding loss but taking into account real aberrations of elements, are 18 % and 38 %, respectively. The effect of pumping depletion begins to manifest itself in the third cascade of a three-stage converter; it may reduce the latter value to {approx}30 %. (nonlinear optical phenomena)

Andreev, N F; Vlasova, K V; Davydov, V S; Kulikov, S M; Makarov, A I; Sukharev, Stanislav A; Freidman, Gennadii I; Shubin, S V

2012-10-31T23:59:59.000Z

42

Plasmonic Quantum Cascade Laser Antenna  

Science Journals Connector (OSTI)

We demonstrate the plasmonic quantum cascade laser antenna, that can confine mid-infrared radiation beyond the diffraction limit, by integrating gold optical antennas on the laser...

Yu, Nanfang; Cubukcu, Ertugrul; Diehl, Laurent; Crozier, Kenneth; Capasso, Federico

43

Cascade and breakdown in scale-free networks with community structure  

Science Journals Connector (OSTI)

The cascade failures in scale-free networks with community structure are studied and cascade propagation of such networks with different modularity parameters is simulated. It is found that the network with small modularity is much easier to trigger cascade failures than that of the larger one. Furthermore, different removal strategies have some what large effects on the cascade failures aftereffect. The simulations also show that larger modularity and reserve capacity coefficient will delay the breakdown caused by a cascade of network. This is particularly important for such real networks with community as traffic networks, distribution networks, and electrical power grids.

Jian-jun Wu; Zi-you Gao; Hui-jun Sun

2006-12-19T23:59:59.000Z

44

Superconvergence of period doubling cascade in trapezoid maps  

E-Print Network [OSTI]

In the symmetric and the asymmetric trapezoid maps, as a slope of the trapezoid is increased, the period doubling cascade occurs and the symbolic sequence of periodic points is the Metropolis-Stein-Stein sequence and the convergence of the onset point of the period 2^m solution to the accumulation point is exponentially fast. We reported these results previously. In this paper, we give the detailed description of the proof on the results. Further, we study the period doubling cascade starting from period p solution and show the superconvergence of the period doubling cascade.

T. Uezu

2000-01-12T23:59:59.000Z

45

Compact Quantum Cascade Laser Transmitter  

SciTech Connect (OSTI)

): In this paper we present design considerations, thermal and optical modeling results, and device performance for a ruggedized, compact laser transmitter that utilizes a room temperature quantum cascade (QC) laser source. The QC laser transmitter is intended for portable mid-infrared (3-12 µm) spectroscopy applications, where the atmospheric transmission window is relatively free of water vapor interference and where the molecular rotational vibration absorption features can be used to detect and uniquely identify chemical compounds of interest. Initial QC laser-based sensor development efforts were constrained by the complications of cryogenic operation. However, improvements in both QC laser designs and fabrication processes have provided room-temperature devices that now enable significant miniaturization and integration potential for national security, environmental monitoring, atmospheric science, and industrial safety applications.

Anheier, Norman C.; Hatchell, Brian K.; Gervais, Kevin L.; Wojcik, Michael D.; Krishnaswami, Kannan; Bernacki, Bruce E.

2009-04-01T23:59:59.000Z

46

Multi-stage Cascaded Stirling Refrigerator  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Multi-stage Cascaded Stirling Refrigerator Multi-stage Cascaded Stirling Refrigerator Los Alamos National Laboratory (LANL) researchers have developed a multi-stage refrigerator,...

47

Theoretical and computational design of terahertz frequency quantum cascade lasers  

Science Journals Connector (OSTI)

Modeling of terahertz frequency quantum cascade lasers has become increasingly complex theoretically resulting in burdensome computational requirements. While more comprehensive treatment permits further insight and increased accuracy the modeling of ...

Adam T. Cooney / A.M. Sarangan

2009-01-01T23:59:59.000Z

48

The Cascaded Humidified Advanced Turbine (CHAT)  

SciTech Connect (OSTI)

This paper introduces the Cascaded Humidified Advanced Turbine (CHAT) plant, a gas turbine based power generation plant utilizing intercooling, reheat, and humidification. It is based upon the integration of an existing heavy duty gas turbine with an additional shaft comprising industrial compressors and high pressure expander. CHAT capitalizes on the latest proven gas turbine technology, which, combined with a sophisticated thermal cycle configuration, results in substantial improvement in gas turbine efficiency, compared to a simple cycle, while still maintaining typical advantages and merits of a combustion turbine plant. Built with a commercial combustion turbine and available industrial compressors and expanders, the CHAT plant does not require extensive product development and testing. As a result, the CHAT power plant can be offered with specific capital costs up to 20 percent lower than the combined cycle plant, and with competing efficiency. Compared to a combined cycle plant, the CHAT plant offers lower emissions (due to air humidification) and other significant operating advantages with regard to start-up time and costs, better efficiency at part load, lower power degradation at higher ambient temperatures, and simpler operations and maintenance due to elimination of the complexities and costs associated with steam production. The CHAT plant also integrates very effectively with coal gasification and particularly well with the water quench design. This feature has been discussed in previous publications.

Nakhamkin, M.; Swensen, E.C. [Energy Storage and Power Consultants, Inc., Mountainside, NJ (United States); Wilson, J.M.; Gaul, G. [Westinghouse Electric Corp., Orlando, FL (United States); Polsky, M. [Polsky Energy Corp., Northbrook, IL (United States)

1996-07-01T23:59:59.000Z

49

Electromagnetic cascades and cascade nucleosynthesis in the early Universe  

Science Journals Connector (OSTI)

We describe a calculation of electromagnetic cascading in radiation and matter in the early Universe initiated by the decay of massive particles or by some other process. We have used a combination of Monte Carlo and numerical techniques which enables us to use exact cross sections, where known, for all the relevant processes. In cascades initiated after the epoch of big bang nucleosynthesis ? rays in the cascades will photodisintegrate He4, producing He3 and deuterium. Using the observed He3 and deuterium abundances we are able to place constraints on the cascade energy deposition as a function of cosmic time. In the case of the decay of massive primordial particles we place limits on the density of massive primordial particles as a function of their mean decay time, and on the expected intensity of decay neutrinos.

R. J. Protheroe; T. Stanev; V. S. Berezinsky

1995-04-15T23:59:59.000Z

50

Further results on gender and cognitive differences in help effectiveness  

E-Print Network [OSTI]

Further results on gender and cognitive differences in help effectiveness Ivon Arroyo1 , Tom Murray, Amherst Abstract. We explored the effectiveness of help for 350 students of different genders sensitive to the amounts of help fitting their needs than to the level of abstraction. On the other hand

Arroyo, Ivon M.

51

Spectral analysis for cascade-emission-based quantum communication in atomic ensembles  

E-Print Network [OSTI]

The ladder configuration of atomic levels provides a source for telecom photons (signal) from the upper atomic transition. \\ For rubidium and cesium atoms, the signal field has the range around 1.3-1.5 $\\mu$m that can be coupled to an optical fiber and transmitted to a remote location. \\ Cascade emission may result in pairs of photons, the signal entangled with the subsequently emitted infrared photon (idler) from the lower atomic transition.\\ This correlated two-photon source is potentially useful in the (Duan-Lukin-Cirac-Zoller) DLCZ protocol for the quantum repeater.\\ We implement the cascade emission to construct a modified DLCZ quantum repeater and investigate the role of time-frequency entanglement in the protocol.\\ The dependence of protocol on photon-number resolving and non-resolving detectors is also studied.\\ We find that frequency entanglement deteriorates the performance but the harmful effect can be diminished by using shorter pump pulses to generate the cascade emission.\\ An optimal cascade-emission-based DLCZ scheme is realized by applying a pure two-photon source in addition to using detectors of perfect quantum efficiency.

H. H. Jen

2014-03-11T23:59:59.000Z

52

Mathematical modeling for a thermionic-AMTEC cascade system  

SciTech Connect (OSTI)

A mathematical modeling of a system consisting of a cascade of a thermionic energy conversion (TIEC) device and an alkali metal thermal to electrical conversion (AMTEC) device has been performed. The TIEC is heated by electron bombardment which converts heat partially into electricity and rejects the remaining. The AMTEC utilizes this reject heat of the TIEC. A mathematical thermal model of the cascade converter has been developed to analyze effects of key parameters such as power level, heat fluxes, temperatures, cascade geometry, etc. In this effort, a 9-node system of nonlinear simultaneous equations has been constructed which is solved by MATHCAD predicting the temperatures of the principal components and the heat flow. Through this study, a better understanding of the thermal coupling of the two converters was gained which helps to produce a more efficient cascade. {copyright} {ital 1996 American Institute of Physics.}

Lodhi, M.A. [Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Schuller, M.; Hausgen, P. [Phillips Laboratory, Kirtland AFB, New Mexico 87117 (United States)

1996-03-01T23:59:59.000Z

53

Enantioselectivity in Organocatalytic Cascade Double Michael Addition Reaction: A Theoretical Study  

Science Journals Connector (OSTI)

(38, 39) To consider the solvent effect on reaction, single-point PCM//B3LYP/6-311++G(d,p) calculations with self-consistent reaction field(40-42) based on polarizable continuum model (PCM)(43, 44) were applied for all gas-phase optimized structures. ... The application of cascade reactions to natural products synthesis represents a particularly demanding task, but the results can be both stunning and instructive. ...

Nan Lu; Lin Meng; Dezhan Chen; Guiqiu Zhang

2011-10-10T23:59:59.000Z

54

Cascade redox flow battery systems  

DOE Patents [OSTI]

A reduction/oxidation ("redox") flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

Horne, Craig R.; Kinoshita, Kim; Hickey, Darren B.; Sha, Jay E.; Bose, Deepak

2014-07-22T23:59:59.000Z

55

Atomistic Modeling of Displacement Cascades in La2Zr2O7 Pyrochlore...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

point defects, such as cations antisites configurations, various interstitials, and vacancies. There is no evidence for direct amorphization within the cascades. The results are...

56

MHK Technologies/Oscillating Cascade Power System OCPS | Open Energy  

Open Energy Info (EERE)

Oscillating Cascade Power System OCPS Oscillating Cascade Power System OCPS < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Oscillating Cascade Power System OCPS.jpg Technology Profile Primary Organization New Energy Solutions LLC Technology Resource Click here Current Technology Type Click here Oscillating Wave Surge Converter Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description The OCPS generator consists of a cascade of vertical hydrofoils submerged in moving water This array of hydrofoils oscillates in antiphase at resonance flutter in a slow swimming motion resulting in maximum power transfer from flowing water to electricity The system efficiently converts the oscillating mechanical energy into a steady electric current A 60 overall water to wire efficiency was demonstrated at the proof of concept test and 65 or better overall efficiency is projected using the new engineering advances incorporated since the test in the commercial model

57

Optimization of control of long-term operating conditions of hydroelectric stations with special reference to the Angara-Enisei cascade of hydroelectric stations  

Science Journals Connector (OSTI)

1. To increase the effectiveness of using water and energy resources by cascades of reservoirs, it is necessary ...

A. Yu. Aleksandrovskii; G. F. Chernenko; N. K. Litvin

1989-08-01T23:59:59.000Z

58

Collision cascades and sputtering induced by larger cluster ions  

SciTech Connect (OSTI)

Recent experimental work on larger cluster impact on solid surfaces suggests large deviations from the standard case of additive sputter yields both in the nuclear and electronic stopping regime. The paper concentrates on elastic collision cascades. In addition to very pronounced spike effects, two phenomena are pointed out that are specific to cluster bombardment. Multiple hits of cluster atoms on one and the same target atom may result in recoil atoms that move faster than the maximum recoil speed for monomer bombardment at the same projectile speed. This effect is important when the atomic mass of a beam atom is less than that of a target atom, M1 << M2. In the opposite case, M1 >> M2, collisions between beam particles may accelerate some beam particles and slow down others. Some consequences are mentioned. Remarks on the nuclear stopping power of larger clusters and on electronic sputtering by cluster bombardment conclude the paper. 38 refs., 2 figs.

Sigmund, P.

1988-01-01T23:59:59.000Z

59

Performance and Reliability of Quantum Cascade Lasers  

SciTech Connect (OSTI)

We present the burn-in behavior and power stability of multiple quantum cascade lasers (QCLs) that were measured to investigate their long-term performance. For these experiments, the current to the QCL was cycled every ten minutes, and the output power was monitored over time for durations as long as two months. A small increase in power for a given injection current is observed for almost all of the QCLs tested during the burn-in period. The data from these experiments will be presented along with the effects of packaging the QCLs to determine the impact on performance and reliability.

Myers, Tanya L.; Cannon, Bret D.; Taubman, Matthew S.; Bernacki, Bruce E.

2013-05-01T23:59:59.000Z

60

Synthesis of Cascade Refrigeration and Liquefaction Systems  

Science Journals Connector (OSTI)

Synthesis of Cascade Refrigeration and Liquefaction Systems ... Current Status and Perspectives of Liquefied Natural Gas (LNG) Plant Design ...

Francisco J. Barnés; C. Judson King

1974-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Interactive Synthesis of Cascade Refrigeration Systems  

Science Journals Connector (OSTI)

Interactive Synthesis of Cascade Refrigeration Systems ... Current Status and Perspectives of Liquefied Natural Gas (LNG) Plant Design ...

Wai Biu Cheng; Richard S. H. Mah

1980-07-01T23:59:59.000Z

62

Aeration efficiency over stepped cascades: Better predictions from flow regimes  

Science Journals Connector (OSTI)

Abstract Stepped cascades are recognized as high potential air–water gas exchangers. In natural rivers, these structures enhance oxygen transfer to water by creating turbulence at interface with increasing air entrainment in water and air–water surface exchange. Stepped cascades could be really useful to improve the natural self-purification process by providing oxygen to aerobic micro-organisms. The aeration performance of these structures depends on several operating and geometrical parameters. In the literature, several empirical correlations for aeration efficiency prediction on stepped cascades exist. Most of these correlations are only applicable for operating and geometrical parameters in the range of which they have been developed. In this paper, 398 experimental sets of data (from our experiments and collected from literature) were used to develop a correlation for aeration prediction over stepped cascades derived from dimensional analysis and parameterized for each individual flow regime in order to consider change in flow regime effect on oxygen transfer. This new correlation allowed calculating the whole set of data obtained for cascades with steps heights between 0.05 m and 0.254 m, cascade total height between 0.25 m and 2.5 m, for discharges per unit of width ranging from 0.28 10?3 m2/s to 600 10?3 m2/s and for cascade steps number between 3 and 25. In these ranges of parameters, standard deviation for aeration efficiency estimation was found to be less than 17%. Finally, advices were proposed to help and improve the structure design in order to improve aeration.

Hatem Khdhiri; Olivier Potier; Jean-Pierre Leclerc

2014-01-01T23:59:59.000Z

63

GaAs–based quantum cascade lasers  

Science Journals Connector (OSTI)

...N. Murdin GaAs-based quantum cascade lasers Sirtori H. Page C. Becker...state-of-the-art of GaAs-based quantum cascade lasers. These new light sources...2000.0739 GaAs-based quantum cascade lasers By C. Sirtori, H. Page...

2001-01-01T23:59:59.000Z

64

Reducing Cascading Failure Risk by Increasing Infrastructure Network Interdependency  

E-Print Network [OSTI]

Increased coupling between critical infrastructure networks, such as power and communications, has important implications for the reliability and security of these networks. To understand the implications of power-communications coupling, researchers have studied interdependent network models and reported that increased coupling can increase system vulnerability [1, 2]. However, these results come from models that have substantially different mechanisms of cascading, relative to those found in actual power and communications networks. This paper reports on two sets of experiments that compare the network vulnerability implications resulting from simple topological models and models that more accurately capture the dynamics of cascading in power systems. In the first set of experiments, we compare a simple model of intra-network cascading to a power grid model and find that the power grid model reveals that power grids have a higher level of vulnerability, relative to what would be inferred from a topological ...

Korkali, Mert; Tivnan, Brian F; Hines, Paul D H

2014-01-01T23:59:59.000Z

65

Village of Cascade | Open Energy Information  

Open Energy Info (EERE)

Cascade Cascade Jump to: navigation, search Name Village of Cascade Facility Village of Cascade Sector Wind energy Facility Type Community Wind Facility Status In Service Owner Village of Cascade Energy Purchaser Village of Cascade Location Cascade WI Coordinates 43.65868218°, -87.99709797° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.65868218,"lon":-87.99709797,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

66

A quantum cascade laser fabricated using planar native-oxide layers C. D. Farmera)  

E-Print Network [OSTI]

of quantum cascade lasers. The native oxide of the Al0.48In0.52As upper cladding layer was formed and usedA quantum cascade laser fabricated using planar native-oxide layers C. D. Farmera) Department to provide electrical and optical confinement for lasers operating at 5 m. Initial results include 1.4 W peak

67

Ugi post-condensation copper-triggered oxidative cascade towards pyrazoles  

E-Print Network [OSTI]

1310 Ugi post-condensation copper-triggered oxidative cascade towards pyrazoles Aurélie Dos Santos-component Ugi coupling, the resulting hydrazone was engaged in a copper triggered [3 + 2] cycloaddition/aerobic oxidation cascade. 1310 Introduction In the last twenty years, the Ugi reaction coupled with its various

Paris-Sud XI, Université de

68

Rapid Cascade Synthesis of Poly-Heterocyclic Architectures from Indigo  

Science Journals Connector (OSTI)

Bubbling CO2 gas through a standard reaction (entry 3) resulted in a 6% yield of 8, however, the most significant outcome from this reaction is the notably reduced yields of 4, 5, 6, and 7, and a dramatic increase in the production of noncharacterizable baseline material. ... There have been reported syntheses of these natural products including the silver-catalyzed cascade synthesis of their parent compound and analogs, with this approach involving the initial intermolecular reaction of two components of similar molecular complexity, however, this necessitated the prior synthesis of these two components. ... Branching Cascades: A Concise Synthetic Strategy Targeting Diverse and Complex Molecular Frameworks ...

Alireza Shakoori; John B. Bremner; Anthony C. Willis; Rachada Haritakun; Paul A. Keller

2013-06-26T23:59:59.000Z

69

Seed size strongly affects cascades on random networks  

Science Journals Connector (OSTI)

The average avalanche size in the Watts model of threshold dynamics on random networks of arbitrary degree distribution is determined analytically. Existence criteria for global cascades are shown to depend sensitively on the size of the initial seed disturbance. The dependence of cascade size upon the mean degree z of the network is known to exhibit several transitions—these are typically continuous at low z and discontinuous at high z; here it is demonstrated that the low-z transition may in fact be discontinuous in certain parameter regimes. Connections between these results and the zero-temperature random-field Ising model on random graphs are discussed.

James P. Gleeson and Diarmuid J. Cahalane

2007-05-03T23:59:59.000Z

70

Josephson cascade micromaser  

SciTech Connect (OSTI)

The possibility of maser action using a current-biased {ital mesoscopic} Josephson junction in a high-{ital Q} {ital microcavity} is discussed. A mesoscopic Josephson junction behaves like an artificial atom as far as the interaction with the photon field is concerned. Under a certain bias current, the Josephson {open_quote}{open_quote}atom{close_quote}{close_quote} is resonantly excited or pumped by quantum-mechanical fluctuations of the Josephson phase, i.e., macroscopic resonant tunneling. When the pumping overcomes the loss of photons from the cavity, maser action is possible. Quantum statistical properties of photons are also investigated numerically, taking into acount the microcavity effect on the basis of a Jaynes-Cummings model with pumping and cavity damping. We found that a mesoscopic Josephson junction within the high-{ital Q} microcavity acts as a thresholdless maser with sub-Poissonian photon statstics. {copyright} {ital 1996 The American Physical Society.}

Hatakenaka, N.; Kurihara, S. [NTT Basic Research Laboratories, Atsugi, Kanagawa 243-01 (Japan)] [NTT Basic Research Laboratories, Atsugi, Kanagawa 243-01 (Japan)

1996-08-01T23:59:59.000Z

71

Power Grid Defense Against Malicious Cascading Failure  

E-Print Network [OSTI]

An adversary looking to disrupt a power grid may look to target certain substations and sources of power generation to initiate a cascading failure that maximizes the number of customers without electricity. This is particularly an important concern when the enemy has the capability to launch cyber-attacks as practical concerns (i.e. avoiding disruption of service, presence of legacy systems, etc.) may hinder security. Hence, a defender can harden the security posture at certain power stations but may lack the time and resources to do this for the entire power grid. We model a power grid as a graph and introduce the cascading failure game in which both the defender and attacker choose a subset of power stations such as to minimize (maximize) the number of consumers having access to producers of power. We formalize problems for identifying both mixed and deterministic strategies for both players, prove complexity results under a variety of different scenarios, identify tractable cases, and develop algorithms f...

Shakarian, Paulo; Lindelauf, Roy

2014-01-01T23:59:59.000Z

72

Multiplexity-facilitated cascades in networks  

Science Journals Connector (OSTI)

Elements of networks interact in many ways, so modeling them with graphs requires multiple types of edges (or network layers). Here we show that such multiplex networks are generically more vulnerable to global cascades than simplex networks. We generalize the threshold cascade model [Watts, Proc. Natl. Acad. Sci. USA 99, 5766 (2002)] to multiplex networks, in which a node activates if a sufficiently large fraction of neighbors in any layer are active. We show that both combining layers (i.e., realizing other interactions play a role) and splitting a network into layers (i.e., recognizing distinct kinds of interactions) facilitate cascades. Notably, layers unsusceptible to global cascades can cooperatively achieve them if coupled. On one hand, this suggests fundamental limitations on predicting cascades without full knowledge of a system's multiplexity; on the other hand, it offers feasible means to control cascades by introducing or removing sparse layers in an existing network.

Charles D. Brummitt; Kyu-Min Lee; K.-I. Goh

2012-04-27T23:59:59.000Z

73

Cascade-induced synchrony in stochastically driven neuronal networks  

Science Journals Connector (OSTI)

Perfect spike-to-spike synchrony is studied in all-to-all coupled networks of identical excitatory, current-based, integrate-and-fire neurons with delta-impulse coupling currents and Poisson spike-train external drive. This synchrony is induced by repeated cascading “total firing events,” during which all neurons fire at once. In this regime, the network exhibits nearly periodic dynamics, switching between an effectively uncoupled state and a cascade-coupled total firing state. The probability of cascading total firing events occurring in the network is computed through a combinatorial analysis conditioned upon the random time when the first neuron fires and using the probability distribution of the subthreshold membrane potentials for the remaining neurons in the network. The probability distribution of the former is found from a first-passage-time problem described by a Fokker-Planck equation, which is solved analytically via an eigenfunction expansion. The latter is found using a central limit argument via a calculation of the cumulants of a single neuronal voltage. The influence of additional physiological effects that hinder or eliminate cascade-induced synchrony are also investigated. Conditions for the validity of the approximations made in the analytical derivations are discussed and verified via direct numerical simulations.

Katherine A. Newhall; Gregor Kova?i?; Peter R. Kramer; David Cai

2010-10-01T23:59:59.000Z

74

Multiwavelength and supercontinuum quantum cascade lasers  

Science Journals Connector (OSTI)

Bandstructure engineering of intersubband optical transitions has led to a new class of quantum cascade lasers (QCL) that simultaneously emit multiple wavelengths by suitable...

Capasso, Federico; Gmachl, Claire; Sivco, Deborah; Cho, Al

75

Quantum Cascade Lasers: Coming of Age  

Science Journals Connector (OSTI)

The quantum cascade laser, first realized in 1994, has now demonstrated operation over an extremely wide wavelength range extending from the mid-infrared to the...

Faist, Jerome

76

Electrically tunable terahertz quantum cascade lasers  

E-Print Network [OSTI]

In this thesis, microelectromechanical systems (MEMS) assisted electrically tunable terahertz quantum cascade lasers (THz QCLs) are designed and demonstrated. Two MEMS tuner devices are proposed to achieve electrically ...

Han, Ningren

2013-01-01T23:59:59.000Z

77

Cascade Control and Defense in Complex Networks  

Science Journals Connector (OSTI)

Complex networks with a heterogeneous distribution of loads may undergo a global cascade of overload failures when highly loaded nodes or edges are removed due to attacks or failures. Since a small attack or failure has the potential to trigger a global cascade, a fundamental question regards the possible strategies of defense to prevent the cascade from propagating through the entire network. Here we introduce and investigate a costless strategy of defense based on a selective further removal of nodes and edges, right after the initial attack or failure. This intentional removal of network elements is shown to drastically reduce the size of the cascade.

Adilson E. Motter

2004-08-26T23:59:59.000Z

78

High-resolution emission spectra of pulsed terahertz quantum-cascade lasers  

SciTech Connect (OSTI)

The spectra of pulsed terahertz quantum-cascade lasers were measured with high spectral resolution. The characteristic line width at half maximum was 0.01 cm{sup -1}; it is controlled by laser temperature variations during the supply voltage pulse. It was shown that an increase in the laser temperature leads to a decrease in the emission frequency, which is caused by an increase in the effective refractive index of the active region. It was also found that a decrease in the supply voltage results in a decrease in the emission frequency, which is caused by a change in the energy of diagonal transitions between lasing levels.

Ikonnikov, A. V., E-mail: antikon@ipm.sci-nnov.ru; Antonov, A. V.; Lastovkin, A. A.; Gavrilenko, V. I. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Sadof'ev, Yu. G.; Samal, N. [Trion Technology (United States)

2010-11-15T23:59:59.000Z

79

Counterintuitive MCNPX Results for Scintillator Surface Roughness Effect  

SciTech Connect (OSTI)

We have reported on our recent MCNPX simulation results of energy deposition for a group of 8 scintillation detectors, coupled with various rough surface patterns. The MCNPX results generally favored the detectors with various rough surface patterns. The observed MCNPX results are not fully explained by this work.

None

2012-08-12T23:59:59.000Z

80

Dynamical Distribution of Capacities Strategy for Suppressing Cascading Failure in Power Grid  

Science Journals Connector (OSTI)

This paper studies the suppressing effect of Dynamical distribution of capacities (DDC) strategy in cascading failure of power grid. This strategy is proposed based on load characteristics and transmission method...

Zhi-Juan Jia; Yu Zhang; Cong Feng; Ming-Sheng Hu

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

The Influence of Doping on the Performance of Terahertz Quantum-Cascade-Lasers  

Science Journals Connector (OSTI)

We present the effects of the doping concentration on a set of terahertz quantum-cascade-lasers emitting around 2.75 THz. The threshold current density decreases linearly with the...

Benz, Alexander; Fasching, Gernot; Andrews, Aaron Maxwell; Unterrainer, Karl; Roch, Tomas; Schrenk, Werner; Strasser, Gottfried

82

Quantum Cascade Laser Technology for the Ultrasensitive Detection of Low-Level Nitric Oxide  

Science Journals Connector (OSTI)

Several spectroscopic methods based on mid-infrared quantum cascade lasers for the ultrasensitive detection of nitric oxide ... the most effective techniques, i.e., laser absorption spectroscopy, cavity-enhanced ...

Angela Elia; Pietro Mario Lugarà; Cinzia Di Franco; Vincenzo Spagnolo

2011-01-01T23:59:59.000Z

83

Dynamic theory of cascades on finite clustered random networks with a threshold rule  

Science Journals Connector (OSTI)

Cascade dynamics on networks are usually analyzed statically to determine existence criteria for cascades. Here, the Watts model of threshold dynamics on random Erd?s-Rényi networks is analyzed to determine the dynamic time evolution of cascades. The network is assumed to have a specific finite number of nodes n and is not assumed to be treelike. All combinations of threshold ?, network average nodal degree z, and seed sizes |S| from a single node up are included. The analysis permits study of network size effects and increased clustering coefficient. Several size effects not found by infinite network theory are predicted by the analysis and confirmed by simulations. In the region of ? and z where a single node can start a cascade, cascades are expanding, in the sense that each step flips a larger group than the previous step did. We show that this region extends to larger values of z than predicted by infinite network analyses. In the region where larger seeds are needed (size proportional to n), cascades begin by contracting: at the outset, each step flips fewer nodes than the previous step, but eventually the process reverses and becomes expanding. A critical mass that grows during the cascade beyond an easily-calculated threshold is identified as the cause of this reversal.

Daniel E. Whitney

2010-12-08T23:59:59.000Z

84

Simulation Modeling of an Enhanced Low-Emission Swirl-Cascade Burner  

SciTech Connect (OSTI)

''Cascade-burners'' is a passive technique to control the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. Cascade-burners have shown advantages over other techniques; its reliability, flexibility, safety, and cost makes it more attractive and desirable. On the other hand, the application of ''Swirl-burners'' has shown superiority in producing a stable flame under a variety of operating conditions and fuel types. The basic idea is to impart swirl to the air or fuel stream, or both. This not only helps to stabilize the flame but also enhances mixing in the combustion zone. As a result, nonpremixed (diffusion) swirl burners have been increasingly used in industrial combustion systems such as gas turbines, boilers, and furnaces, due to their advantages of safety and stability. Despite the advantages of cascade and swirl burners, both are passive control techniques, which resulted in a moderate pollutant emissions reduction compared to SCR, SNCR and FGR (active) methods. The present investigation will study the prospects of combining both techniques in what to be named as ''an enhanced swirl-cascade burner''. Natural gas jet diffusion flames in baseline, cascade, swirl, and swirl-cascade burners were numerically modeled using CFDRC package. The thermal, composition, and flow (velocity) fields were simulated. The numerical results showed that swirl and cascade burners have a more efficient fuel/air mixing, a shorter flame, and a lower NOx emission levels, compared to the baseline case. The results also revealed that the optimal configurations of the cascaded and swirling flames have not produced an improved performance when combined together in a ''swirl-cascade burner''. The non-linearity and complexity of the system accounts for such a result, and therefore, all possible combinations, i.e. swirl numbers (SN) versus venturi diameter ratios (D/d), need to be considered.

Ala Qubbaj

2004-09-01T23:59:59.000Z

85

Exergy analysis of a vapour compression-absorption cascaded refrigeration system using modified Gouy-Stodola equation  

Science Journals Connector (OSTI)

In the present study, the performance of vapour compression-absorption cascaded refrigeration system (VCACRS) is studied with modified Gouy-Stodola equation and the results are compared with the classical approach of exergy evaluation. The quantitative difference in two approaches is presented which necessitates the need to employ modified approach. The expressions are formulated for effective temperature and real irreversible loss for different components of VCACRS. The overall performance of system can be improved by increasing the evaporator and generator temperature and by decreasing the absorber, cascade condenser and condenser temperature. Coefficient of structural bonds (CSB) analysis shows evaporator is relatively more sensitive to change in its temperature as compared with the other components.

Vaibhav Jain; Surendra Singh Kachhwaha; Gulshan Sachdeva

2014-01-01T23:59:59.000Z

86

Short-term cascaded hydroelectric system scheduling based on chaotic particle swarm optimization using improved logistic map  

Science Journals Connector (OSTI)

In order to solve the model of short-term cascaded hydroelectric system scheduling, a novel chaotic particle swarm optimization (CPSO) algorithm using improved logistic map is introduced, which uses the water discharge as the decision variables combined with the death penalty function. According to the principle of maximum power generation, the proposed approach makes use of the ergodicity, symmetry and stochastic property of improved logistic chaotic map for enhancing the performance of particle swarm optimization (PSO) algorithm. The new hybrid method has been examined and tested on two test functions and a practical cascaded hydroelectric system. The experimental results show that the effectiveness and robustness of the proposed CPSO algorithm in comparison with other traditional algorithms.

Yaoyao He; Shanlin Yang; Qifa Xu

2013-01-01T23:59:59.000Z

87

Atomic-Scale Simulations of Cascade Overlap and Damage Evolution...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Atomic-Scale Simulations of Cascade Overlap and Damage Evolution in Silicon Carbide. Atomic-Scale Simulations of Cascade Overlap and Damage Evolution in Silicon Carbide. Abstract:...

88

Multiple-junction quantum cascade photodetectors for thermophotovoltaic energy conversion  

Science Journals Connector (OSTI)

The use of intersubband transitions in quantum cascade structures for thermophotovoltaic energy conversion is investigated numerically. The intrinsic cascading scheme, spectral...

Yin, Jian; Paiella, Roberto

2010-01-01T23:59:59.000Z

89

Recent progress in high precision atmospheric trace gas instruments using mid-infrared quantum cascade lasers  

Science Journals Connector (OSTI)

We report results from high precision spectroscopic instruments for atmospheric trace gases using with mid-IR quantum cascade lasers. Numerous gases can be measured with 1s absorption...

McManus, John B; Zahniser, Mark; Nelson, David; McGovern, Ryan; Agnese, Mike

90

Akermanite in the Cascade Slide xenolith and its significance for regional metamorphism in the Adirondacks  

Science Journals Connector (OSTI)

Akermanite (Ak90) coexists with monticellite (Mo92) and wollastonite (Wo99...) in an unusual calc-silicate xenolith in anorthosite at Cascade Slide in the Adirondack Mountains, New York. Experimental results bear...

J. W. Valley; E. J. Essene

1980-01-01T23:59:59.000Z

91

External cavity quantum cascade laser  

Science Journals Connector (OSTI)

In this paper we review the progress of the development of mid-infrared quantum cascade lasers (QCLs) operated in an external cavity configuration. We concentrate on QCLs based on the bound-to-continuum design, since this design is especially suitable for broadband applications. Since they were first demonstrated, these laser-based tunable sources have improved in performance in terms of output power, duty cycle, operation temperature and tuneability. Nowadays they are an interesting alternative to FTIRs for some applications. They operate at room temperature, feature a high spectral resolution while being small in size. They were successfully used in different absorption spectroscopy techniques. Due to their vast potential for applications in industry, medicine, security and research, these sources enjoy increasing interest within the research community as well as in industry.

Andreas Hugi; Richard Maulini; Jérôme Faist

2010-01-01T23:59:59.000Z

92

Does removal of an alien predator from small islands in the Baltic Sea induce a trophic cascade?  

E-Print Network [OSTI]

Does removal of an alien predator from small islands in the Baltic Sea induce a trophic cascade known as a trophic cascade. Because alien predators can have a disproportionate impact, compared communities than native predators. We studied the indirect effects of the removal of an alien predator

Oksanen, Lauri

93

SIMULATION MODELING OF AN ENHANCED LOW-EMISSION SWIRL-CASCADE BURNER  

SciTech Connect (OSTI)

Based on the physical and computational models outlined in the previous technical progress reports, Natural gas jet diffusion flames in baseline, cascade, swirl, and swirlcascade burners were numerically modeled. The thermal, composition, and flow (velocity) fields were simulated. The temperature, CO{sub 2} and O{sub 2} concentrations, as well as the axial and radial velocity profiles were computed and analyzed. The numerical results showed that swirl and cascade burners have a more efficient fuel/air mixing, a shorter flame, and a lower NOx emission levels, compared to the baseline case. The results also revealed that the optimal configurations of the cascaded and swirling flames have not produced an improved performance when combined together in a ''swirl-cascade burner''.

Ala Qubbaj

2004-04-01T23:59:59.000Z

94

Heat Flow From Four New Research Drill Holes In The Western Cascades,  

Open Energy Info (EERE)

From Four New Research Drill Holes In The Western Cascades, From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Details Activities (1) Areas (1) Regions (0) Abstract: Conceptual models of the thermal structure of the Oregon Cascade Range propose either (1) a narrow zone of magmatic heat sources, flanked by shallow heat-flow anomalies caused by lateral ground-water flow; or (2) a wide zone of magmatic heat sources, with localized, generally negligible ground-water effects. The proposed narrow heat source coincides with the Quaternary volcanic arc, whereas the wider heat source would extend 10-30 km west of the arc. To test the models, four new heat-flow holes were sited

95

The Impact of the Topology on Cascading Failures in Electric Power Grids  

E-Print Network [OSTI]

Cascading failures are one of the main reasons for blackouts in power transmission grids. The topology of a power grid, together with its operative state determine, for the most part, the robustness of the power grid against cascading failures. Secure electrical power supply requires, together with careful operation, a robust design of the electrical power grid topology. This paper investigates the impact of a power grid topology on its robustness against cascading failures. Currently, the impact of the topology on a grid robustness is mainly assessed by using purely topological approaches that fail to capture the essence of electric power flow. This paper proposes a metric, the effective graph resistance, that relates the topology of a power grid to its robustness against cascading failures by deliberate attacks, while also taking the fundamental characteristics of the electric power grid into account such as power flow allocation according to Kirchoff Laws. Experimental verification shows that the proposed ...

Koç, Yakup; Van Mieghem, Piet; Kooij, Robert E; Brazier, Frances M T

2014-01-01T23:59:59.000Z

96

US geothermal database and Oregon cascade thermal studies: (Final report)  

SciTech Connect (OSTI)

This report describes two tasks of different nature. The first of these tasks was the preparation of a data base for heat flow and associated ancillary information for the United States. This data base is being used as the basis for preparation of the United States portion of a geothermal map of North America. The ''Geothermal Map of North America'' will be published as part of the Decade of North American Geology (DNAG) series of the Geological Society of America. The second of these tasks was to make a geothermal evaluation of holes drilled in the Cascade Range as part of a Department of Energy (DOE)/Industry co-sponsored deep drilling project. This second task involved field work, making temperature logs in the holes, and laboratory work, measuring thermal conductivity measurements on an extensive set of samples from these holes. The culmination of this task was an interpretation of heat flow values in terms of the regional thermal conditions; implications for geothermal systems in the Cascade Range; evaluation of the effect of groundwater flow on the depths that need to be drilled for successful measurements in the Cascade Range; and investigation of the nature of the surface groundwater effects on the temperature-depth curves. 40 refs., 7 figs., 7 tabs.

Blackwell, D.D.; Steele, J.L.; Carter, L.

1988-05-01T23:59:59.000Z

97

Product Lifecycle Approach to Cascade Impaction Measurements  

Science Journals Connector (OSTI)

During development of an orally inhaled product (OIP), its full-resolution Aerodynamic Particle Size...in vitro performance (1,2). The pharmacopeial eight-stage Andersen Cascade Impactor (ACI) or Next-Generation ...

Terrence P. Tougas; Dave Christopher; Jolyon Mitchell…

2011-03-01T23:59:59.000Z

98

Modeling techniques for quantum cascade lasers  

E-Print Network [OSTI]

Quantum cascade lasers are unipolar semiconductor lasers covering a wide range of the infrared and terahertz spectrum. Lasing action is achieved by using optical intersubband transitions between quantized states in specifically designed multiple-quantum-well heterostructures. A systematic improvement of quantum cascade lasers with respect to operating temperature, efficiency and spectral range requires detailed modeling of the underlying physical processes in these structures. Moreover, the quantum cascade laser constitutes a versatile model device for the development and improvement of simulation techniques in nano- and optoelectronics. This review provides a comprehensive survey and discussion of the modeling techniques used for the simulation of quantum cascade lasers. The main focus is on the modeling of carrier transport in the nanostructured gain medium, while the simulation of the optical cavity is covered at a more basic level. Specifically, the transfer matrix and finite difference methods for solvin...

Jirauschek, Christian

2014-01-01T23:59:59.000Z

99

Quantum Cascade Lasers Emitting below 3 µm  

Science Journals Connector (OSTI)

First quantum cascade lasers emitting below 3 µm are demonstrated. The lasers based on the InAs/AlSb material system emit at 2.95-2.97 µm at 83 K and operate up to room temperature.

Devenson, Jan; Teissier, Roland; Cathabard, Olivier; Baranov, Alexei N

100

Emission spectra of terahertz quantum cascade laser  

Science Journals Connector (OSTI)

We calculated energy levels, wave functions, and energies of radiative transitions in terahertz quantum cascade lasers based on GaAs/Al0.15Ga0.85As heterostructures. Current-voltage characteristics and current de...

A. V. Antonov; V. I. Gavrilenko; A. V. Ikonnikov…

2009-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Frequency tuning of THz quantum cascade lasers  

Science Journals Connector (OSTI)

Tunable single-mode THz quantum cascade lasers are crucial for spectroscopy applications. Current and temperature tuning are limited to a few GHz and other solutions have to be...

Tredicucci, Alessandro

102

The critical tension in the 6D Cascading DGP model  

E-Print Network [OSTI]

We investigate the presence of ghosts in the Cascading DGP model. We start by discussing the problem of the cosmological late time acceleration, and we introduce the modified gravity approach. We then focus on brane induced gravity models and in particular on the Cascading DGP model. We consider a specific realization of the latter model, and we study first order perturbations around pure tension solutions. In the scalar sector of a 4D scalar-vector-tensor decomposition, the dynamics on the 4D brane can be described by a master equation where a critical tension emerges in a suitable 4D limit. We give a geometrical interpretation of this critical tension, and explain its relevance for the presence of ghosts in the theory. We comment on the difference between our result and the one present in the literature, and stress its importance regarding the phenomenological viability of the model. We finally provide a numerical check which confirms the validity of our analysis.

Sbisa', Fulvio

2014-01-01T23:59:59.000Z

103

Finite-time cascaded tracking control approach for mobile robots  

Science Journals Connector (OSTI)

Abstract This paper develops a new control approach for trajectory tracking of mobile robots. For the purpose of tracking trajectory, the error dynamics of a mobile robot are divided into a first-order subsystem and a second-order subsystem by using a cascaded control design. Firstly, a global finite-time control law of the angular velocity is designed for the first-order system in order to stabilize the angle error of mobile robots. Subsequently, a finite-time sliding mode control law of forward velocity is synthesized, which guarantees the global stability of the second-order subsystem. Furthermore, the global uniform stability of the whole closed-loop system is analyzed by employing cascaded control theory, and some sufficient conditions are derived. Finally, the proposed control algorithm is applied to mobile robots, where simulation results demonstrate good convergence and performance.

Yangming Zhang; Guorong Liu; Biao Luo

2014-01-01T23:59:59.000Z

104

CP-violation in SUSY cascades at the LHC  

E-Print Network [OSTI]

We study the potential to observe CP-violating effects in SUSY cascade decay chains at the LHC. Asymmetries composed by triple products of momenta of the final state particles are sensitive to CP-violating effects. Due to large boosts that dilute the asymmetries, these can be difficult to observe. Extending the methods of momentum reconstruction we show that the original size of these asymmetries may be measurable. A study is done at the hadronic level with backgrounds to estimate the expected sensitivity at the LHC.

Jamie Tattersall; Gudrid Moortgat-Pick; Krzysztof Rolbiecki

2010-09-01T23:59:59.000Z

105

E-Print Network 3.0 - anti cancer effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

cancer effects Search Powered by Explorit Topic List Advanced Search Sample search results for: anti cancer effects Page: << < 1 2 3 4 5 > >> 1 Scientific American: News In Brief:...

106

Cascade Municipal Utilities | Open Energy Information  

Open Energy Info (EERE)

Cascade Municipal Utilities Cascade Municipal Utilities Jump to: navigation, search Name Cascade Municipal Utilities Place Iowa Utility Id 3137 Utility Location Yes Ownership M NERC Location MRO NERC MRO Yes ISO MISO Yes Operates Generating Plant Yes Activity Generation Yes Activity Transmission Yes Activity Distribution Yes References EIA Form EIA-861 Final Data File for 2010 - File1_a[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Utility Rate Schedules Grid-background.png All Electric Rate Residential City/Interdept. Rate Commercial Commercial Rate 3-phase Commercial Commercial Rate Single-phase Commercial Demand Rate Industrial Residential Rates Residential Average Rates Residential: $0.1040/kWh

107

E-Print Network 3.0 - adverse health effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Powered by Explorit Topic List Advanced Search Sample search results for: adverse health effects Page: << < 1 2 3 4 5 > >> 1 Regulation of Animal Health Products FDACVM:...

108

Influence of nonparabolicity on electronic structure of quantum cascade laser  

Science Journals Connector (OSTI)

Abstract We analyze the influence of nonparabolicity on the bound electronic states in the conduction-band of quantum wells in external electric field. Numerical results, obtained by transfer matrix method are presented for active region of GaAs/Al0.3Ga0.7As quantum cascade laser. The structure was initially optimized by genetic algorithm, using Kane's model of nonparabolicity, with emission wavelength set to ? ? 15.1 ?m . However, our numerical results indicate the change in lasing wavelength to 14.04 ?m when using a more comprehensive description of nonparabolicity.

Nikola Vukovi?; Vitomir Milanovi?; Jelena Radovanovi?

2014-01-01T23:59:59.000Z

109

Hydrothermal monitoring data from the Cascade Range, northwestern United States  

E-Print Network [OSTI]

Hydrothermal monitoring data from the Cascade Range, northwestern United States By S.E. Ingebritsen., and Evans, W.C., 2014, Hydrothermal monitoring data from the Cascade Range, northwestern United States: U ...................................................................................................................................27 (8) Carbonate springs

110

Energy Cascading Combined with Thermal Energy Storage in Industry  

Science Journals Connector (OSTI)

The opportunities for energy conservation through the application of storage cascades has not previously been examined in...

R. J. Wood; D. T. Baldwin; P. W. O’Callaghan…

1983-01-01T23:59:59.000Z

111

Data Acquisition-Manipulation At Cascades Region (Ingebritsen...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Data Acquisition-Manipulation At Cascades Region (Ingebritsen & Mariner, 2010) Exploration...

112

An experimental and computational study of transonic three-dimensional flow in a turbine cascade  

SciTech Connect (OSTI)

Detailed experimental measurements of the flow in a cascade of turbine rotor blades with a nonplanar end wall are reported. The cascade geometry was chosen to model as closely as possible that of a H.P. gas turbine rotor blade. The blade section is designed for supersonic flow with an exit Mach number of 1.15 and the experiments covered a range of exit Mach numbers from 0.7-1.2. Significant three-dimensional effects were observed and the origin of these is discussed. The measurements are compared with data for the same blade section in a two-dimensional cascade and also with the predictions of two different fully three-dimensional inviscid flow calculation methods. It is found that both these calculations predict the major threedimensional effects on the flow correctly.

Camus, J.J.; Denton, J.D.; Scrivener, C.T.J.; Soulis, J.V.

1984-04-01T23:59:59.000Z

113

Cascade of elimination and emergence of pure cooperation in coevolutionary games on networks  

Science Journals Connector (OSTI)

We propose a coevolutionary game to study cooperative behavior in the presence of catastrophic phenomenon. We incorporate tolerance to elimination of individuals in network games where individuals update their strategies synchronously, and there are no birth of individuals and stochastic effects. We find that an avalanchelike death process can arise when defection strategies exist and individuals are vulnerable to deficiency of profits. Strikingly, we observe that, after such a cascading process terminates, cooperators are the sole survivors regardless of the game types and of the connection patterns among individuals as determined by the network topology. Cooperation thus becomes the optimal strategy and absolutely outperforms defection. Our results can yield insights into evolution of cooperation in the presence of catastrophic events in social and natural systems.

Wen-Xu Wang; Rui Yang; Ying-Cheng Lai

2010-03-30T23:59:59.000Z

114

Emission Measurement with Quantum Cascade Laser  

Science Journals Connector (OSTI)

With the Mexa-1400QL-NX Horiba offers a new exhaust gas measurement solution which is based on the Quantum Cascade Laser technology. The new method is able to...2, N2O and NH3 emissions and is a tool for research...

Matthias Schröder; Dipl.-Phys. Daniel Scheder; Werner Czika

2011-05-01T23:59:59.000Z

115

Sequential resonant tunneling in quantum cascade lasers  

SciTech Connect (OSTI)

A model of sequential resonant tunneling transport among two-dimensional subbands that takes into account explicitly elastic scattering is investigated. It is compared to transport measurements performed on quantum cascade lasers, where resonant tunneling processes are known to be dominating. Excellent agreement is found between experiment and theory over a large range of current, temperature, and device structures.

Terazzi, Romain; Gresch, Tobias; Wittmann, Andreas; Faist, Jerome [Quantum Optoelectronics Group, Institute for Quantum Electronics, ETH, 8086 Zuerich (Switzerland)

2008-10-15T23:59:59.000Z

116

13 - Terahertz (THz) quantum cascade lasers  

Science Journals Connector (OSTI)

Abstract: This chapter is dedicated to terahertz (THz) quantum cascade laser technology. After a brief introduction that contains a description of the current state of the art in terms of performance, the following important technological aspects are reviewed in more detail: waveguide and photonic structures, frequency and phase stabilisation, and active mode-locking.

S. Barbieri; S. Kumar

2013-01-01T23:59:59.000Z

117

STATEMENT OF CONSIDERATIONS REQUEs·r BY CASCADE ENGINEERI NG, INC. (CASCADE) FOR AN ADVANCE  

Broader source: Energy.gov (indexed) [DOE]

REQUEs·r BY CASCADE ENGINEERI REQUEs·r BY CASCADE ENGINEERI NG, INC. (CASCADE) FOR AN ADVANCE WA IVER OF DOMESTIC AND FORE IGN PATENT RIGHTS UNDER DOE AWARD NO. DE-EE0005440; W(A) 201 1-070 CASCAD E has requested a waiver of domesti c and fore ign patent rights of the United States of America in all subject inventions arising from its participation under the above refe renced cooperative agreeme nt entitl ed " Innovative Ballasted Flat Roof Solar PV Racking System." According to the Statement o f Project Objectives, the objectives of the project funded by the cooperative agreement arc to " [ dlesign, develop, engineer, manufacture, and market a flat roof so lar PV racking sys tem. This racking system will o±Ier a cost advantage from a materials and installation labor (mechanical and electrical) perspective. It will be flexible enough to

118

Broadband Distributed Feedback Quantum Cascade Laser Array Using a Heterogeneous Cascade  

Science Journals Connector (OSTI)

We demonstrated an array of distributed feedback quantum cascade lasers covering a spectral range of 220cm-1. The variability in threshold current and slope efficiency is explained in...

Diehl, Laurent; Lee, Benjamin G; Zhang, Haifei A; Pflügl, Christian; Belkin, Mikhail; Fisher, Milan; Wittman, Andreas; Faist, Jerome; Capasso, Federico

119

Delayed MeV-GeV Gamma-Ray Photons in Gamma-Ray Bursts: An Effect of Electromagnetic Cascades of Very High Energy Gamma Rays in the Infrared/Microwave Background  

Science Journals Connector (OSTI)

We show that the electromagnetic cascade of very high energy gamma-rays from gamma-ray bursts in the IR/microwave background will produce delayed MeV-GeV photons. Monte Carlo simulations have been performed to study this process. The distance of GB 940217 is estimated to be not less than 120 Mpc using our model, which supports a cosmological origin for this source. We also show that the time delays of gamma-ray photons are inversely proportional to their energy. Our model does not require the presence of intergalactic magnetic fields.

L. X. Cheng; K.

1996-01-01T23:59:59.000Z

120

Self-consistent thermal simulation of GaAs/Al0.45Ga0.55As quantum cascade lasers  

Science Journals Connector (OSTI)

This paper presents a self-consistent thermal model for quantum cascade lasers (QCLs) that takes into account the nonuniform heat generation distribution in the active region as well as the temperature dependences of the heat generation rate and thermal ... Keywords: Heating, Monte Carlo, Nonlinear effects, Phonon transport, Quantum cascade lasers, Thermal model

Y. B. Shi; Z. Aksamija; I. Knezevic

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

DETAILED COMPARISON BETWEEN PARTON CASCADE AND HADRONIC CASCADE AT SPS AND RHIC.  

SciTech Connect (OSTI)

The authors study the importance of the partonic phase produced in relativistic heavy ion collision by comparing the parton cascade model and the hadronic cascade model. Hadron yield, baryon stopping and transverse momentum distribution are calculated with JAM and discussions are given comparing with VNI. Both of these models give good description of experimental data. They also discuss the strangeness production mechanism and the directed transverse flow.

NARA,Y.

1998-10-23T23:59:59.000Z

122

Thermodynamic analysis of a transcritical CO2/propylene (R744–R1270) cascade system for cooling and heating applications  

Science Journals Connector (OSTI)

Abstract In this paper natural refrigerant propylene (R1270) has been proposed for transcritical cascade refrigeration system and analyzed. Propylene is used in the low temperature (LT) cycle and carbon dioxide is used in the high temperature (HT) cycle of the cascade transcritical refrigeration system. The proposed transcritical cascade cycle can be used for simultaneous cooling and heating applications. Thermal performance of the cascade cycle is evaluated for different combinations of design and operating variables and optimum performance parameters such as Topt, \\{COPmax\\} and mass flow of propylene and CO2 have been predicted. Design parameters include the evaporator temperature of LT cycle (TE), gas cooler outlet temperature (TC) and cascade heat exchanger temperature difference (DT). The results of the analysis show better thermal performance of CO2–propylene transcritical cycle than subcritical cascade cycle and also better than N2O–CO2 transcritical cycle. A methodology to obtain relevant performance diagrams and regression correlations to serve as a guideline for the design and optimization of transcritical CO2–propylene cascade system has been developed.

Alok Manas Dubey; Suresh Kumar; Ghanshyam Das Agrawal

2014-01-01T23:59:59.000Z

123

Effect of penetration rate and filter location on piezocone test results  

Science Journals Connector (OSTI)

The effects of penetration rate on the piezocone penetration and dissipation test results with filter element...K o...condition using a well-calibrated chamber system. The chamber tests were condu...

Dae Kyu Kim

2004-05-01T23:59:59.000Z

124

E-Print Network 3.0 - air pollutant effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Search Sample search results for: air pollutant effects Page: << < 1 2 3 4 5 > >> 1 Air Pollution Physics and Chemistry EAS 6790 Monday, Wednesday, Friday 2:05 to 2:55...

125

Inverse Kirkendall mixing in collision cascades K. Nordlund* and R. S. Averback  

E-Print Network [OSTI]

in reactor mate- rials, and processing of materials by high strain conditions. Theoretical approaches as Co, but has a much smaller heat of mixing with Cu, comparison of cascade mixing in Ni effect,7 in which a vacancy flux drives a net solute flux in the opposite direction. Classical molecular

Nordlund, Kai

126

Cascade Apartments: Deep Energy Multifamily Retrofit  

SciTech Connect (OSTI)

In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

Gordon, A.; Mattheis, L.; Kunkle, R.; Howard, L.; Lubliner, M.

2014-02-01T23:59:59.000Z

127

Quantum-cascade lasers enable infrared sensors  

SciTech Connect (OSTI)

Quantum-cascade lasers (QCLs) are semiconductor-injection lasers based on intersubband transitions in a multiple-quantum-well heterostructure. They are designed using band-structure engineering and grown by molecular beam epitaxy. The emission wavelength of a QCL is primarily a function of quantum-well thickness--thinner quantum wells lead to shorter wavelengths--and is essentially independent of the material bandgap. Quantum-cascade lasers can be designed to operate at any wavelength from 3.5 m (infrared) to 67 m (terahertz region) and are continuously tunable through ranges of a few inverse centimeters.1, 2, 3 This capability makes them well suited for spectroscopy in the infrared (see Laser Focus World, August 1999, p. 40).

Schultz, John F. (BATTELLE (PACIFIC NW LAB))

2003-05-01T23:59:59.000Z

128

Cascade-based attacks on complex networks  

Science Journals Connector (OSTI)

We live in a modern world supported by large, complex networks. Examples range from financial markets to communication and transportation systems. In many realistic situations the flow of physical quantities in the network, as characterized by the loads on nodes, is important. We show that for such networks where loads can redistribute among the nodes, intentional attacks can lead to a cascade of overload failures, which can in turn cause the entire or a substantial part of the network to collapse. This is relevant for real-world networks that possess a highly heterogeneous distribution of loads, such as the Internet and power grids. We demonstrate that the heterogeneity of these networks makes them particularly vulnerable to attacks in that a large-scale cascade may be triggered by disabling a single key node. This brings obvious concerns on the security of such systems.

Adilson E. Motter and Ying-Cheng Lai

2002-12-20T23:59:59.000Z

129

Cascade Training Technique for Particle Identification  

E-Print Network [OSTI]

The cascade training technique which was developed during our work on the MiniBooNE particle identification has been found to be a very efficient way to improve the selection performance, especially when very low background contamination levels are desired. The detailed description of this technique is presented here based on the MiniBooNE detector Monte Carlo simulations, using both artifical neural networks and boosted decision trees as examples.

Yong Liu; Ion Stancu

2006-11-27T23:59:59.000Z

130

The Effects of Search Engines and Query Operators on Top Ranked Results Bernard J. Jansen  

E-Print Network [OSTI]

The Effects of Search Engines and Query Operators on Top Ranked Results Bernard J. Jansen School of the advanced query operators. Jansen (2000) examines the changes in results when different searching operators queries [3, 4, 8]. Jansen et al. [3] reports a Boolean operator usage of about 8%. Silverstein et al. [8

Jansen, James

131

Criticality safety concerns of uranium deposits in cascade equipment  

SciTech Connect (OSTI)

The Paducah and Portsmouth Gaseous Diffusion Plants enrich uranium in the {sup 235}U isotope by diffusing gaseous uranium hexafluoride (UF{sub 6}) through a porous barrier. The UF{sub 6} gaseous diffusion cascade utilized several thousand {open_quotes}stages{close_quotes} of barrier to produce highly enriched uranium (HEU). Historically, Portsmouth has enriched the Paducah Gaseous Diffusion Plant`s product (typically 1.8 wt% {sup 235}U) as well as natural enrichment feed stock up to 97 wt%. Due to the chemical reactivity of UF{sub 6}, particularly with water, the formation of solid uranium deposits occur at a gaseous diffusion plant. Much of the equipment operates below atmospheric pressure, and deposits are formed when atmospheric air enters the cascade. Deposits may also be formed from UF{sub 6} reactions with oil, UF{sub 6} reactions with the metallic surfaces of equipment, and desublimation of UF{sub 6}. The major deposits form as a result of moist air in leakage due to failure of compressor casing flanges, blow-off plates, seals, expansion joint convolutions, and instrument lines. This report describes criticality concerns and deposit disposition.

Plaster, M.J. [Lockheed Martin Utility Services, Inc., Piketon, OH (United States)

1996-12-31T23:59:59.000Z

132

Modified gravity, the Cascading DGP model and its critical tension  

E-Print Network [OSTI]

We investigate the presence of instabilities in the Cascading DGP model. We start by discussing the problem of the cosmological late time acceleration, and we introduce the modified gravity approach. We then focus on brane induced gravity models and in particular on the Cascading DGP model. We consider configurations of the latter model where the source term is given simply by vacuum energy (pure tension), and we study perturbations at first order around these configurations. We perform a four-dimensional scalar-vector-tensor decomposition of the perturbations, and show that, regarding the scalar sector, the dynamics in a suitable limit can be described by a master equation. This master equation contains an energy scale (critical tension) which is related in a non-trivial way to the parameters of the model. We give a geometrical interpretation of why this scale emerges, and explain its relevance for the presence of ghost instabilities in the theory. We comment on the difference between our result and the one present in the literature, and stress its importance regarding the phenomenological viability of the model. We finally provide a numerical check which confirms the validity of our analysis.

Fulvio Sbisa'

2014-12-17T23:59:59.000Z

133

The Role of Damage Cascade in the Nanocrystallization of Metallic Glass  

E-Print Network [OSTI]

was performed, enabling a link between the damage cascade event to the subsequent heat transfer. Modeling results indicate that for 1 MeV Ni ion irradiation in Ni52.5Nb10Zr15Ti15Pt7.5, the heat transfer rate is too large for direct crystallization. Although...

Myers, Michael T.

2011-08-08T23:59:59.000Z

134

INVESTIGATION OF PERIODIC BOUNDARY CONDITIONS IN MULTIPASSAGE CASCADE FLOWS USING OVERSET GRIDS  

E-Print Network [OSTI]

. Computational results are presented for two and four passage, subsonic and tran­ sonic flows through a turbine and a compressor cascade. The overset grid solutions over the multi­passage periodic domains agree well in Refers to inflow exit Refers to outflow a Acoustic speed A Max. amplitude of the plunging motion c Blade

Tuncer, Ismail H.

135

Linking Marketing and Engineering Product Design Decisions via Analytical Target Cascading  

E-Print Network [OSTI]

Linking Marketing and Engineering Product Design Decisions via Analytical Target CascadingÃ? Jeremy to consumers and are feasible to produce. The resulting marketing and engineering design goals are driven decisions when the two problems are interrelated. A meth- od new to the marketing community, analytical

Papalambros, Panos

136

Innovative biomass to power conversion systems based on cascaded supercritical CO2 Brayton cycles  

Science Journals Connector (OSTI)

Abstract In the small to medium power range the main technologies for the conversion of biomass sources into electricity are based either on reciprocating internal combustion or organic Rankine cycle engines. Relatively low energy conversion efficiencies are obtained in both systems due to the thermodynamic losses in the conversion of biomass into syngas in the former, and to the high temperature difference in the heat transfer between combustion gases and working fluid in the latter. The aim of this paper is to demonstrate that higher efficiencies in the conversion of biomass sources into electricity can be obtained using systems based on the supercritical closed CO2 Brayton cycles (s-CO2). The s-CO2 system analysed here includes two cascaded supercritical CO2 cycles which enable to overcome the intrinsic limitation of the single cycle in the effective utilization of the whole heat available from flue gases. Both part-flow and simple supercritical CO2 cycle configurations are considered and four boiler arrangements are investigated to explore the thermodynamic performance of such systems. These power plant configurations, which were never explored in the literature for biomass conversion into electricity, are demonstrated here to be viable options to increase the energy conversion efficiency of small-to-medium biomass fired power plants. Results of the optimization procedure show that a maximum biomass to electricity conversion efficiency of 36% can be achieved using the cascaded configuration including a part flow topping cycle, which is approximately 10%-points higher than that of the existing biomass power plants in the small to medium power range.

Giovanni Manente; Andrea Lazzaretto

2014-01-01T23:59:59.000Z

137

EM to Proceed with Demolition Following Completion of Cascade Cleanout  

Broader source: Energy.gov (indexed) [DOE]

to Proceed with Demolition Following Completion of Cascade to Proceed with Demolition Following Completion of Cascade Cleanout Operations EM to Proceed with Demolition Following Completion of Cascade Cleanout Operations July 1, 2012 - 12:00pm Addthis X-326 Facility Manager Jack Tully, left to right, DOE Site Lead Joel Bradburne and Operator Russ Nickell stand in the local control room after the last processing equipment that had been operating in the uranium enrichment cascade at the Portsmouth site in Piketon was shut down. X-326 Facility Manager Jack Tully, left to right, DOE Site Lead Joel Bradburne and Operator Russ Nickell stand in the local control room after the last processing equipment that had been operating in the uranium enrichment cascade at the Portsmouth site in Piketon was shut down. The last equipment that had been operating in the uranium enrichment cascade at the Portsmouth site in Piketon was powered off May 30 after more than 57 years of operation.

138

SPONTANEOUS CURRENT-LAYER FRAGMENTATION AND CASCADING RECONNECTION IN SOLAR FLARES. I. MODEL AND ANALYSIS  

SciTech Connect (OSTI)

Magnetic reconnection is commonly considered to be a mechanism of solar (eruptive) flares. A deeper study of this scenario reveals, however, a number of open issues. Among them is the fundamental question of how the magnetic energy is transferred from large, accumulation scales to plasma scales where its actual dissipation takes place. In order to investigate this transfer over a broad range of scales, we address this question by means of a high-resolution MHD simulation. The simulation results indicate that the magnetic-energy transfer to small scales is realized via a cascade of consecutively smaller and smaller flux ropes (plasmoids), analogous to the vortex-tube cascade in (incompressible) fluid dynamics. Both tearing and (driven) 'fragmenting coalescence' processes are equally important for the consecutive fragmentation of the magnetic field (and associated current density) into smaller elements. At the later stages, a dynamic balance between tearing and coalescence processes reveals a steady (power-law) scaling typical of cascading processes. It is shown that cascading reconnection also addresses other open issues in solar-flare research, such as the duality between the regular large-scale picture of (eruptive) flares and the observed signatures of fragmented (chaotic) energy release, as well as the huge number of accelerated particles. Indeed, spontaneous current-layer fragmentation and the formation of multiple channelized dissipative/acceleration regions embedded in the current layer appear to be intrinsic to the cascading process. The multiple small-scale current sheets may also facilitate the acceleration of a large number of particles. The structure, distribution, and dynamics of the embedded potential acceleration regions in a current layer fragmented by cascading reconnection are studied and discussed.

Barta, Miroslav; Buechner, Joerg [Max Planck Institute for Solar System Research, D-37191 Katlenburg-Lindau (Germany); Karlicky, Marian; Skala, Jan, E-mail: barta@mps.mpg.de [Astronomical Institute of the Academy of Sciences of the Czech Republic, CZ-25165 Ondrejov (Czech Republic)

2011-08-10T23:59:59.000Z

139

Cascading Failures in Power Grid under Three Node Attack Strategies  

Science Journals Connector (OSTI)

This paper studies cascading failures of power grid under three node attack strategies based on...k is k ? , and ?...is a tunable parameter. We investigated the...

Sui-Min Jia; Yun-Ye Wang; Cong Feng; Zhi-Juan Jia…

2014-01-01T23:59:59.000Z

140

Building America Whole-House Solutions for Existing Homes: Cascade...  

Broader source: Energy.gov (indexed) [DOE]

Building America Whole-House Solutions for Existing Homes: Cascade Apartments - Deep Energy Multifamily Retrofit (Fact Sheet) Building America Whole-House Solutions for Existing...

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Identifying two steps in the internal wave energy cascade  

E-Print Network [OSTI]

1.1.1 The internal wave energy cascade . . . . . . .? ? , which contain only wave energy trav- eling upward anddistinction is made between wave energy propagating upward

Sun, Oliver Ming-Teh

2010-01-01T23:59:59.000Z

142

Random?walk model of isotope enrichment in cascades  

Science Journals Connector (OSTI)

Steady opertional parameters such as enrichment flow rates isotopic distributions in the product and in the waste and their variation over the cascade are evaluated in terms of transit probabilities and average transit times of different gas molecules in their random walk from one stage to another of a cascade. The random?walk model is also used for describing transient properties i.e. the output response to input perturbation and the relaxation time. Calculations in terms of the model are carried out for UF6 of natural abundance enriched in a diffusion cascade. With the appropriate numerical values the model can also be applied to centrifuge cascades.

I. Kiss; Sz. Vass

1977-01-01T23:59:59.000Z

143

Active wavelength control of an external cavity quantum cascade laser  

Science Journals Connector (OSTI)

Semiconductor lasers are increasingly popular as components of high...1]. Quantum Cascade Lasers (QCLs) are particularly attractive semiconductor lasers, since their operating wavelengths in the mid...2...]. For ...

T. Tsai; G. Wysocki

2012-11-01T23:59:59.000Z

144

Low-Divergence Surface-Emitting Terahertz Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We investigate surface-emission via a second-order grating in terahertz quantum cascade lasers. We optimize grating design and suppress facet reflectivity with absorbing waveguide...

Fan, Jonathan; Belkin, Mikhail; Capasso, Federico; Khanna, Suraj; Lachab, Mohammed; Davies, Giles; Linfield, Edmund

145

Chirped Laser Dispersion Spectroscopy with Directly Modulated Quantum Cascade Laser  

Science Journals Connector (OSTI)

A feasibility study of chirped laser dispersion spectroscopy (CLaDS) with utilizing direct modulation of a quantum cascade laser instead of external modulators is presented....

Hangauer, Andreas; Spinner, Georg; Nikodem, Michal; Wysocki, Gerard

146

Current Injection Spiral-Shaped Chaotic Microcavity Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We report room temperature operation of current-injection quantum cascade lasers with spiral-shaped chaotic microresonators, capable of directional, single mode emission, operating...

Belkin, Mikhail A; Audet, Ross M; Fan, Jonathan A; Capasso, Federico; Narimanov, Evgenii; Bour, D; Corzine, S; Zhu, J; Höfler, G

147

Hydrothermal Heat Discharge In The Cascade Range, Northwestern...  

Open Energy Info (EERE)

Heat Discharge In The Cascade Range, Northwestern United States Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Hydrothermal Heat Discharge In...

148

Result-Driven Exploration of Simulation Parameter Spaces for Visual Effects Design  

E-Print Network [OSTI]

Result-Driven Exploration of Simulation Parameter Spaces for Visual Effects Design Stefan Bruckner visualization system then allows the user to explore the simulation space in a goal-oriented manner. Animation to modify the simulation parameters via standard con- trols such as sliders or numeric input fields

149

ROTIGOTINE TRANSDERMAL PATCH IS EFFECTIVE IN THE TREATMENT OF IDIOPATHIC RLS: RESULTS OF A 6-MONTH,  

E-Print Network [OSTI]

ROTIGOTINE TRANSDERMAL PATCH IS EFFECTIVE IN THE TREATMENT OF IDIOPATHIC RLS: RESULTS OF A 6-MONTH of the SP792 study group Objective: To evaluate efficacy and safety of rotigotine transdermal patch. Conclusion: Therapy with rotigotine transdermal patch in doses of 2 and 3 mg/24h over a period of 6 months

Lichtarge, Olivier

150

Spin Glass Computations and Ruelle's Probability Cascades  

E-Print Network [OSTI]

We study the Parisi functional, appearing in the Parisi formula for the pressure of the SK model, as a functional on Ruelle's Probability Cascades (RPC). Computation techniques for the RPC formulation of the functional are developed. They are used to derive continuity and monotonicity properties of the functional retrieving a theorem of Guerra. We also detail the connection between the Aizenman-Sims-Starr variational principle and the Parisi formula. As a final application of the techniques, we rederive the Almeida-Thouless line in the spirit of Toninelli but relying on the RPC structure.

Louis-Pierre Arguin

2006-08-17T23:59:59.000Z

151

Multiplicative cascades and seismicity in natural time  

Science Journals Connector (OSTI)

Natural time ? enables the distinction of two origins of self-similarity, i.e., the process memory and the process increments infinite variance. Employing multiplicative cascades in natural time, the most probable value of the variance ?1(???2?????2) is explicitly related with the parameter b of the Gutenberg-Richter law of randomly shuffled earthquake data. Moreover, the existence of temporal and magnitude correlations is studied in the original earthquake data. Magnitude correlations are larger for closer in time earthquakes, when the maximum interoccurrence time varies from half a day to 1 min.

N. V. Sarlis; E. S. Skordas; P. A. Varotsos

2009-08-11T23:59:59.000Z

152

Free Energy Cascade in Gyrokinetic Turbulence  

SciTech Connect (OSTI)

In gyrokinetic theory, the quadratic nonlinearity is known to play an important role in the dynamics by redistributing (in a conservative fashion) the free energy between the various active scales. In the present study, the free energy transfer is analyzed for the case of ion temperature gradient driven turbulence. It is shown that it shares many properties with the energy transfer in fluid turbulence. In particular, one finds a (strongly) local, forward (from large to small scales) cascade of free energy in the plane perpendicular to the background magnetic field. These findings shed light on some fundamental properties of plasma turbulence, and encourage the development of large-eddy-simulation techniques for gyrokinetics.

Banon Navarro, A.; Morel, P.; Albrecht-Marc, M.; Carati, D. [Universite Libre de Bruxelles, Faculte des Sciences, Physique Statistique et Plasmas CP 231, EURATOM Association, Campus Plaine, 1050 Brussels (Belgium); Merz, F.; Goerler, T.; Jenko, F. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany)

2011-02-04T23:59:59.000Z

153

Remote Chemical Sensing Using Quantum Cascade Lasers  

SciTech Connect (OSTI)

Research done by the IR sensors team at PNNL is focused on developing advanced spectroscopic methods for detecting signatures of nuclear, chemical, biological and explosives weapons or weapons production. The sensors we develop fall into two categories: remote sensors that can be operated at distances ranging from 150 m to 10 km, and point sensors that are used for in-situ inspection and detection. FY03 has seen an explosion in FM DIAL progress with the net result being solid confirmation that FM DIAL is a technique capable of remote chemical monitoring in a wide variety of venues. For example, FM DIAL was used to detect a small plume of hydrogen sulfide, a candidate CW agent, released in the desert environment of the Hanford 200 Area site. These experiments were conducted over a range of physical conditions including outside temperatures ranging from 70 F to 105 F and turbulence conditions ranging from quiescent to chaotic. We are now rapidly developing the information needed to design prototype FM DIAL systems that are optimized for specific applications that include scenarios such as fixed position stand-off detection and mobile UAV mounted remote monitoring. Just as an example, in FY04 we will use FM DIAL to detect both in-facility and outdoor release of enriched UF6. The rapid progress in FM DIAL research made in FY03 is attributed to several advances. First, final construction of a custom-designed trailer allowed the instrument to be housed in a mobile temperature-controlled environment. This allowed the experiment to be transported to several locations so that data could be collected under a range of physical conditions. This has led to a better understanding of a variety of experimental noise sources. With this knowledge, we have been able to implement several changes in the way the FM DIAL data is collected and processed, with the net result being a drastic improvement in our confidence of analyte concentration measurement and an improvement i n the instrument detection limit. The range of chemicals detectable by FM DIAL has also been extended. Prior to FY03 only water and nitrous oxide (N2O) had been seen. Experiments on extending the tuning range of the quantum cascade laser (QCL) currently used in the experiments demonstrate that many more species are now accessible including H2S, C2F4H2, and CH4. We additionally demonstrated that FM DIAL measurements can be made using short wave infrared (SWIR) telecommunications lasers. While measurements made using these components are noisier because turbulence and particulate matter cause more interference in this spectral region, monitoring in this region enables larger species to be detected simply because these lasers have a greater tuning range. In addition, SWIR monitoring also allows for the detection of second-row hydride species such as HF and HCl, which are important nuclear and CWA proliferation signatures.

Harper, Warren W.; Strasburg, Jana D.; Aker, Pam M.; Schultz, John F.

2004-01-20T23:59:59.000Z

154

Controllable discrete diffraction in cascade-induced waveguides  

SciTech Connect (OSTI)

A new method for generating periodic lattices in quadratically nonlinear media by the three-wave cascade interaction is proposed. This method allows one to obtain stable structures with changeable parameters. These structures make it possible to realise the all-optical control of the character of the laser beam propagation. The use of the discrete diffraction allows the signal multiplexing in optical processing and information transfer devices and the control of the number of channels at the crystal output. The effect of the discrete diffraction anisotropy in the system of induced waveguides makes it possible to redistribute in the specified way the energy in the channels at the output. It is shown that the optical switching efficiency is maximal in the regime of the transverse Bragg resonance. The signal switching rate in optical lattices induced in a quadratically nonlinear medium is limited by the time of light propagation though the crystal and can achieve several terahertz. (nonlinear optical phenomena)

Borovkova, O V; Lobanov, V E; Sukhorukov, Anatolii P [M. V. Lomonosov Moscow State University, Faculty of Physics, Moscow (Russian Federation); Sukhorukova, A K [Russian State Geological Prospecting University, Moscow (Russian Federation)

2009-11-30T23:59:59.000Z

155

Multicomponent cnoidal waves in cascade parametric frequency conversion  

SciTech Connect (OSTI)

It is shown that four-mode interaction in quasi-synchronous cascade frequency conversion on a quadratic nonlinearity can be described in terms of an effective cubic nonlinearity, which reduces the problem to solving the system of two coupled nonlinear Schroedinger equations (NSEs) with respect to the amplitudes of waves involved in both nonlinear processes. Analytic solutions of a new type found for this system have the form of cnoidal waves with components representing the sum and difference of the identical fundamental solutions of the NSE with shifted arguments. The obtained solutions cover the entire range of variation of boundary conditions, allowing the optimisation of the conversion efficiency in any particular situation. (nonlinear optical phenomena)

Petnikova, V M; Shuvalov, Vladimir V [International Laser Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation)

2008-12-31T23:59:59.000Z

156

Molecular Dynamics Simulation of Cascade-Induced Ballistic Helium Resolutioning from Bubbles in Iron  

SciTech Connect (OSTI)

Molecular dynamics simulations have been used to assess the ability of atomic displacement cascades to eject helium from small bubbles in iron. This study of the ballistic resolutioning mechanism employed a recently-developed Fe-He interatomic potential in concert with an iron potential developed by Ackland and co-workers. The primary variables examined were: irradiation temperature (100 and 600K), cascade energy (5 and 20 keV), bubble radius (0.5 and 1.0 nm), and He-to-vacancy ratio in the bubble (0.25, 0.5 and 1.0). Systematic trends were observed for each of these variables. For example, ballistic resolutioning leads to a greater number of helium atoms being displaced from larger bubbles and from bubbles that have a higher He/vacancy ratio (bubble pressure). He resolutioning was reduced at 600K relative to 100K, and for 20 keV cascades relative to 5 keV cascades. Overall, the results indicate a modest level of He removal by ballistic resolutioning. The results can be used to provide guidance in selection of a resolution parameter that can be employed in cluster dynamics models to predict the bubble size distribution that evolves under irradiation.

Stoller, Roger E [ORNL] [ORNL

2013-01-01T23:59:59.000Z

157

Terahertz quantum cascade lasers based on resonant phonon scattering for depopulation  

Science Journals Connector (OSTI)

...Michael Pepper Terahertz quantum cascade lasers based on resonant phonon...development of terahertz (THz) quantum cascade lasers (QCLs), in which the depopulation...intersubband|quantum wells|quantum cascade lasers|longitudinal optical...

2004-01-01T23:59:59.000Z

158

A high carrier injection terahertz quantum cascade laser based on indirectly pumped scheme  

SciTech Connect (OSTI)

A Terahertz quantum cascade laser with a rather high injection coupling strength based on an indirectly pumped scheme is designed and experimentally implemented. To effectively suppress leakage current, the chosen quantum cascade module of the device is based on a five-well GaAs/Al{sub 0.25}Ga{sub 0.75}As structure. The device lases up to 151?K with a lasing frequency of 2.67 THz. This study shows that the effect of higher energy states in carrier transport and the long-range tunnel coupling between states that belong to non-neighbouring modules have to be considered in quantum design of structures with a narrow injector barrier. Moreover, the effect of interface roughness scattering between the lasing states on threshold current is crucial.

Razavipour, S. G., E-mail: sgrazavi@uwaterloo.ca; Xu, C.; Wasilewski, Z. R.; Ban, D. [Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. W., Waterloo, Ontario N2L3G1 (Canada); Dupont, E.; Laframboise, S. R. [National Research Council, Blg. M-50, 1200 Montreal Rd., Ottawa, Ontario K1A0R6 (Canada); Chan, C. W. I.; Hu, Q. [Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-01-27T23:59:59.000Z

159

Analytical investigation of the dynamics behaviors of quantum cascade laser  

Science Journals Connector (OSTI)

Abstract In this paper, we investigate analytically and numerically the transient dynamics of the mid-infrared quantum cascade laser operating in a single mode. The approach is based on using adiabatic elimination in the rate equations model. Analytical solutions are derived for steady-state and time-dependent number of electrons in the various levels, population inversion and number of photons in the cavity. In addition, the equation that allows for the determination of time for steady-state establishment is derived within the premises of our analytical model in the most general case. The results are compared with numerical calculations. The dependence of the buildup time on current injection is also examined and compared with our other existing model.

A. Hamadou

2015-01-01T23:59:59.000Z

160

Energy flow along the medium-induced parton cascade  

E-Print Network [OSTI]

We discuss the dynamics of parton cascades that develop in dense QCD matter, and contrast their properties with those of similar cascades of gluon radiation in vacuum. We argue that such cascades belong to two distinct classes that are characterized respectively by an increasing or a constant (or decreasing) branching rate along the cascade. In the former class, of which the BDMPS, medium-induced, cascade constitutes a typical example, it takes a finite time to transport a finite amount of energy to very soft quanta, while this time is essentially infinite in the latter case, to which the DGLAP cascade belongs. The medium induced cascade is accompanied by a constant flow of energy towards arbitrary soft modes, leading eventually to the accumulation of the initial energy of the leading particle at zero energy. It also exhibits scaling properties akin to wave turbulence. These properties do not show up in the cascade that develops in vacuum. There, the energy accumulates in the spectrum at smaller and smaller e...

Blaizot, Jean-Paul

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

A Cascade Multilevel Inverter Using a Single DC Source  

E-Print Network [OSTI]

A Cascade Multilevel Inverter Using a Single DC Source Zhong Du1, Leon M. Tolbert2 3, John N inverter can be implemented using only a single DC power source and capacitors. A standard cascade multilevel inverter requires DC sources for 2 + 1 levels. Without requiring transformers, the scheme proposed

Tolbert, Leon M.

162

Computational Analysis of Cascading Failures in Power Networks  

E-Print Network [OSTI]

of smart grid measurement and control algorithms that can mitigate a cascade. Categories and Subject. Specifically, we consider performance metrics such as the distance between failures, the length of the cascade (under different metrics) is NP-hard. Finally, for specific graphs, we develop a fast algorithm

Shepard, Kenneth

163

Bandstructure and electronic states in terahertz quantum cascade lasers  

Science Journals Connector (OSTI)

Bandstructure and electron eigenstates in terahertz Quantum Cascade Lasers (QCLs) are studied by using the Quantum Transmitting Boundary Method (QTBM). It has several advantages compared to the commonly used Transfer Matrix Method (TMM). ... Keywords: QCL, QTBM, TMM, bandstructure, electron eigenstates, nanoscale technology, nanotechnology, quantum cascade lasers, quantum transmitting boundary methods, transfer matrix methods

Jing Tao Lu; Jun Cheng Cao

2006-06-01T23:59:59.000Z

164

1st workshop on diffusion networks and cascade analytics  

Science Journals Connector (OSTI)

Diffusion and cascades have been studied for many years in sociology, and different theoretical models have been developed. However, experimental validation has been always carried out in relatively small datasets. In recent years, with the availability ... Keywords: cascade modeling, diffusion networks

Peng Cui; Fei Wang; Hanghang Tong; Manuel Gomez Rodriguez

2014-02-01T23:59:59.000Z

165

THE ROLE OF OCCUPATIONAL SAFETY IN ORGANIZATIONAL TRUST, AND ITS EFFECTS ON THE ORGANIZATIONAL RESULTS 1  

E-Print Network [OSTI]

Abstract: Today, trust in work environment is one of important sources of competitive advantage. While today organizations, strongly need organizational trust for their success, development of it get one of the main concerns of today organizations ’ management. On the other hand, according to scientists ’ opinions, management of occupational safety can enhance organizational trust. Positive and effective relationship between occupational safety and organizational trust, increase and simplify organizational relations, and as a result, will improve working operation and efficiency. Purpose of this study was operational study, and method of gathering data was scientific-comparative. Statistical population of this research is TV and Radio staffs of Markazi province. Iran, and analyzed statistical model participants are 160 persons. Information gathering method of this research is questionnaire and operativeadmission analyze test, used to data analyzing, and finally all of study hypothesizes admitted. Results of research hypothesis examination suggested that occupational safety has positive effect on organizational trust. In addition, occupational safety also has effects on organizational working outcome, and finally, organizational trust has positive effect on organizational working outcome.

Habibollah Javanmard; Sahar Havasi; Islamic Azad

166

Field Mapping At Cascades Region (Ingebritsen & Mariner, 2010) | Open  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Field Mapping At Cascades Region (Ingebritsen & Mariner, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Field Mapping At Cascades Region (Ingebritsen & Mariner, 2010) Exploration Activity Details Location Cascades Geothermal Region Exploration Technique Field Mapping Activity Date Usefulness not indicated DOE-funding Unknown References S. E. Ingebritsen, R. H. Mariner (2010) Hydrothermal Heat Discharge In The Cascade Range, Northwestern United States Retrieved from "http://en.openei.org/w/index.php?title=Field_Mapping_At_Cascades_Region_(Ingebritsen_%26_Mariner,_2010)&oldid=510730"

167

LNG cascading damage study. Volume I, fracture testing report.  

SciTech Connect (OSTI)

As part of the liquefied natural gas (LNG) Cascading Damage Study, a series of structural tests were conducted to investigate the thermal induced fracture of steel plate structures. The thermal stresses were achieved by applying liquid nitrogen (LN{sub 2}) onto sections of each steel plate. In addition to inducing large thermal stresses, the lowering of the steel temperature simultaneously reduced the fracture toughness. Liquid nitrogen was used as a surrogate for LNG due to safety concerns and since the temperature of LN{sub 2} is similar (-190 C) to LNG (-161 C). The use of LN{sub 2} ensured that the tests could achieve cryogenic temperatures in the range an actual vessel would encounter during a LNG spill. There were four phases to this test series. Phase I was the initial exploratory stage, which was used to develop the testing process. In the Phase II series of tests, larger plates were used and tested until fracture. The plate sizes ranged from 4 ft square pieces to 6 ft square sections with thicknesses from 1/4 inches to 3/4 inches. This phase investigated the cooling rates on larger plates and the effect of different notch geometries (stress concentrations used to initiate brittle fracture). Phase II was divided into two sections, Phase II-A and Phase II-B. Phase II-A used standard A36 steel, while Phase II-B used marine grade steels. In Phase III, the test structures were significantly larger, in the range of 12 ft by 12 ft by 3 ft high. These structures were designed with more complex geometries to include features similar to those on LNG vessels. The final test phase, Phase IV, investigated differences in the heat transfer (cooling rates) between LNG and LN{sub 2}. All of the tests conducted in this study are used in subsequent parts of the LNG Cascading Damage Study, specifically the computational analyses.

Petti, Jason P.; Kalan, Robert J.

2011-12-01T23:59:59.000Z

168

Cost-Effective Choices of Marine Fuels in a Carbon-Constrained World: Results from a Global Energy Model  

Science Journals Connector (OSTI)

Cost-Effective Choices of Marine Fuels in a Carbon-Constrained World: Results from a Global Energy Model ... † Department

Maria Taljegard; Selma Brynolf; Maria Grahn; Karin Andersson; Hannes Johnson

2014-10-06T23:59:59.000Z

169

Effects of Nuclear Data Library on BFS and ZPPR k{sub eff} Analysis Results  

SciTech Connect (OSTI)

The data-processing system CONSYST/ABBN coupled with the ABBN-93 nuclear data library (NDL) was used in the analysis of BFS-62 and ZPPR JUPITER experiment series fast reactor mixed oxide cores, applying the Japan Nuclear Cycle Development Institute (JNC), Japan, core calculation code CITATION-FBR. The FFCP cell code was used to take into account the spatial cell heterogeneity and resonance effects based on the subgroup approach.The NDL effect has been studied by comparing the results calculated using the ABBN-93 nuclear data with the former ones obtained at JNC based on the JENDL-3.2 NDL. Calculation analysis results for the k{sub eff} parameter for four BFS-62 cores as well as for three ZPPR JUPITER experiment series cores (ZPPR-9, ZPPR-13A, and ZPPR-17A) have been obtained. The estimated uncertainty in the k{sub eff} values caused by possible errors in calculation of the applied corrections was estimated to be {approx}0.3% in the case of the ZPPR cores and 0.2% for the BFS-62 cores. The NDL effect determined by applying the ABBN-93 nuclear data in the JNC calculation route for the k{sub eff} parameter appeared to be {approx}0.3% for the ZPPR and BFS-62 cores with plutonium. As for BFS-62 uranium-loaded cores, the NDL effect was {approx}0.1%. Sensitivity analysis was applied, and it has shown that the main contributors to the NDL effect are uranium, plutonium, and iron cross sections.This work is closely related to the JNC-Institute of Physics and Power Engineering, Russian Federation, collaboration on experimental investigation of excess weapon plutonium disposition in the BN-600 reactor using the BFS facility.

Manturov, Gennadi [Japan Nuclear Cycle Development Institute (Japan)

2003-07-15T23:59:59.000Z

170

Cascade Sierra Solutions CSS | Open Energy Information  

Open Energy Info (EERE)

Sierra Solutions CSS Sierra Solutions CSS Jump to: navigation, search Name Cascade Sierra Solutions (CSS) Place Coburg, Oregon Zip 97408-1313 Product Oregon-based, non-profit organization dedicated to saving fuel and reducing emissions from heavy-duty diesel engines. Coordinates 50.263202°, 10.966202° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":50.263202,"lon":10.966202,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

171

Highly temperature insensitive quantum cascade lasers  

SciTech Connect (OSTI)

An InP based quantum cascade laser (QCL) heterostructure emitting around 5 {mu}m is grown with gas-source molecular beam epitaxy. The QCL core design takes a shallow-well approach to maximize the characteristic temperatures, T{sub 0} and T{sub 1}, for operations above room temperature. A T{sub 0} value of 383 K and a T{sub 1} value of 645 K are obtained within a temperature range of 298-373 K. In room temperature continuous wave operation, this design gives a single facet output power of 3 W and a wall plug efficiency of 16% from a device with a cavity length of 5 mm and a ridge width of 8 {mu}m.

Bai, Y.; Bandyopadhyay, N.; Tsao, S.; Selcuk, E.; Slivken, S.; Razeghi, M. [Department of Electrical Engineering and Computer Science, Center for Quantum Devices, Northwestern University, Evanston, Illinois 60208 (United States)

2010-12-20T23:59:59.000Z

172

A multifrequency interband two-cascade laser  

SciTech Connect (OSTI)

Multifrequency lasing in a new class of injection heterolasers, i.e., in an interband two-cascade laser with a tunneling p-n junction separating two active regions of quantum wells located in the same waveguide is obtained and studied. The developed laser structure with pulsed pumping provided the simultaneous emission of two first-order modes with the wavelengths of 1.063 and 0.98 {mu}m and two third-order modes with the wavelengths of 0.951 and 0.894 {mu}m. Due to nonlinear mixing of the modes within the laser cavity, the generation of the second harmonics and sum frequencies was observed.

Biryukov, A. A.; Zvonkov, B. N.; Nekorkin, S. M.; Demina, P. B.; Semenov, N. N. [Research Physicotechnical Institute at the Nizhni Novgorod State University (Russian Federation); Aleshkin, V. Ya.; Gavrilenko, V. I.; Dubinov, A. A., E-mail: sanya@ipm.sci-nnov.ru; Marem'yanin, K. V.; Morozov, S. V. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Belyanin, A. A.; Kocharovsky, V. V. [Texas A and M University, Department of Physics (United States); Kocharovsky, Vl. V. [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)

2007-10-15T23:59:59.000Z

173

CONTROL OF POLLUTANT EMISSIONS IN NATURAL GAS DIFFUSION FLAMES BY USING CASCADE BURNERS  

SciTech Connect (OSTI)

The goal of this exploratory research project is to control the pollutant emissions of diffusion flames by modifying the air infusion rate into the flame. The modification was achieved by installing a cascade of venturis around the burning gas jet. The basic idea behind this technique is controlling the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. A natural gas jet diffusion flame at burner-exit Reynolds number of 5100 was examined with a set of venturis of specific sizes and spacing arrangement. The thermal and composition fields of the baseline and venturi-cascaded flames were numerically simulated using CFD-ACE+, an advanced computational environment software package. The instantaneous chemistry model was used as the reaction model. The concentration of NO was determined through CFD-POST, a post processing utility program for CFD-ACE+. The numerical results showed that, in the near-burner, midflame and far-burner regions, the venturi-cascaded flame had lower temperature by an average of 13%, 19% and 17%, respectively, and lower CO{sub 2} concentration by 35%, 37% and 32%, respectively, than the baseline flame. An opposite trend was noticed for O{sub 2} concentration; the cascaded flame has higher O{sub 2} concentration by 7%, 26% and 44%, in average values, in the near-burner, mid-flame and far-burner regions, respectively, than in the baseline case. The results also showed that, in the near-burner, mid-flame, and far-burner regions, the venturi-cascaded flame has lower NO concentrations by 89%, 70% and 70%, in average values, respectively, compared to the baseline case. The numerical results substantiate that venturi-cascading is a feasible method for controlling the pollutant emissions of a burning gas jet. In addition, the numerical results were useful to understand the thermo-chemical processes involved. The results showed that the prompt-NO mechanism plays an important role besides the conventional thermal-NO mechanism. The computational results of the present study need to be validated experimentally.

Dr. Ala Qubbaj

2001-12-30T23:59:59.000Z

174

Optimization of the output and efficiency of a high power cascaded arc hydrogen plasma source  

SciTech Connect (OSTI)

The operation of a cascaded arc hydrogen plasma source was experimentally investigated to provide an empirical basis for the scaling of this source to higher plasma fluxes and efficiencies. The flux and efficiency were determined as a function of the input power, discharge channel diameter, and hydrogen gas flow rate. Measurements of the pressure in the arc channel show that the flow is well described by Poiseuille flow and that the effective heavy particle temperature is approximately 0.8 eV. Interpretation of the measured I-V data in terms of a one-parameter model shows that the plasma production is proportional to the input power, to the square root of the hydrogen flow rate, and is independent of the channel diameter. The observed scaling shows that the dominant power loss mechanism inside the arc channel is one that scales with the effective volume of the plasma in the discharge channel. Measurements on the plasma output with Thomson scattering confirm the linear dependence of the plasma production on the input power. Extrapolation of these results shows that (without a magnetic field) an improvement in the plasma production by a factor of 10 over where it was in van Rooij et al. [Appl. Phys. Lett. 90, 121501 (2007)] should be possible.

Vijvers, W. A. J.; Gils, C. A. J. van; Goedheer, W. J.; Meiden, H. J. van der; Veremiyenko, V. P.; Westerhout, J.; Lopes Cardozo, N. J.; Rooij, G. J. van [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Schram, D. C. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2008-09-15T23:59:59.000Z

175

Commercial Standard 90.1 Cost-Effectiveness Analysis and Results | Building  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Site Map Printable Version Development Adoption Compliance Regulations Resource Center Commercial Standard 90.1 Cost-Effectiveness Analysis and Results The U.S. Department of Energy (DOE) supports the development of cost-effective energy codes and standards to increase efficiency in residential and commercial buildings. Pacific Northwest National Laboratory (PNNL) conducted a series of cost analyses for ANSI/ASHRAE/IES Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings - the commercial model energy code. The cost analyses compare Standard 90.1-2010 to the prior 2007 edition, based on six prototype buildings in five representative U.S. climate zones. PNNL also conducted energy savings analysis for Standard 90.1-2010 and the commercial requirements of the

176

Results obtained using the Plastic Ball  

SciTech Connect (OSTI)

Single-particle inclusive experiments, and experiments that additionally measure a few correlations like the associated multiplicity, have provided the main contribution to our present understanding of high-energy heavy-ion collisions. The results from those experiments are in overall agreement with calculations of the cascade and hydrodynamical models. In the cascade model the collision of two nuclei is simulated as a cascade of nucleon-nucleon collisions using measured N-N cross sections. The hydrodynamical model, on the other hand, describes the nuclear collision as that of two fluids and makes use of a nuclear equation of state relating thermal and compressional energy densities to pressure. The pressure field dominates the expansion phase and leads to collective flow of the reaction products in a preferred direction. The observation of such effects in inclusive experiments is not well established. Collective effects that manifest themselves in the shape of the event in phase space are expected to be seen best in complete event detectors that measure the final state as exclusively as presently possible by measuring most of the charged particles emitted in the reaction. In addition, those detectors are well suited to test macroscopic concepts such as equilibrium and temperature. Global methods like the sphericity or thrust analysis take into account all the correlations measured in the event and are specially designed to determine the shape of an event in phase space and thus to define a reaction plane. Recent data from the Plastic Ball experiment about the study of nuclear stopping and thermalization and on global analysis are presented.

Ritter, H.G.; Gustafsson, H.A.; Gutbrod, H.H.

1983-08-01T23:59:59.000Z

177

Quantum cascade lasers: a versatile source for precise measurements in the mid/far-infrared range  

Science Journals Connector (OSTI)

We provide an overview of recent developments of quantum cascade lasers (QCLs), from the mid-infrared (mid-IR) to the far-IR (THz) range, with a special focus on their metrological-grade applications in a number of fields. A special emphasis on the physics of the QCLs allows underlining peculiar effects and device features recently unveiled that pave the way to novel demanding photonics applications.

S Bartalini; M S Vitiello; P De Natale

2014-01-01T23:59:59.000Z

178

Open standards for cascade models for RHIC: Volume 1. Proceedings of RIKEN BNL Research Center workshop  

SciTech Connect (OSTI)

It is widely recognized that cascade models are potentially effective and powerful tools for interpreting and predicting multi-particle observables in heavy ion physics. However, the lack of common standards, documentation, version control, and accessibility have made it difficult to apply objective scientific criteria for evaluating the many physical and algorithmic assumptions or even to reproduce some published results. The first RIKEN Research Center workshop was proposed by Yang Pang to address this problem by establishing open standards for original codes for applications to nuclear collisions at RHIC energies. The aim of this first workshop is: (1) to prepare a WWW depository site for original source codes and detailed documentation with examples; (2) to develop and perform standardized test for the models such as Lorentz invariance, kinetic theory comparisons, and thermodynamic simulations; (3) to publish a compilation of results of the above work in a journal e.g., ``Heavy Ion Physics``; and (4) to establish a policy statement on a set of minimal requirements for inclusion in the OSCAR-WWW depository.

NONE

1997-10-01T23:59:59.000Z

179

Cascade Natural Gas - Conservation Incentives for New Homes | Department of  

Broader source: Energy.gov (indexed) [DOE]

Cascade Natural Gas - Conservation Incentives for New Homes Cascade Natural Gas - Conservation Incentives for New Homes Cascade Natural Gas - Conservation Incentives for New Homes < Back Eligibility Residential Savings Category Home Weatherization Commercial Weatherization Heating & Cooling Construction Commercial Heating & Cooling Design & Remodeling Sealing Your Home Ventilation Heating Appliances & Electronics Water Heating Program Info State District of Columbia Program Type Utility Rebate Program Rebate Amount High Efficiency Natural Gas Furnace: $150 High Efficiency Natural Gas Hearth: $70 Conventional Natural Gas Water Heater: $40 Condensing Tankless Water Heater: $200 Combined Domestic Water/Hydronic Space Heating System (usingTankless Water Heater): $800 Energy Star Certified Home: $350 Energy Star Certified Plus Home: $750

180

Design and preliminary testing of a thermionic AMTEC cascade  

SciTech Connect (OSTI)

This paper describes the design of an experiment to demonstrate the feasibly of operating a cascade of a Thermionic Energy Converter (TEC) with an Alkali Metal Thermo Electric Converter (AMTEC). Both of these devices convert heat to electricity without moving mechanical parts and lend themselves to be incorporated into a cascade. Typically, the TEC operates from a hot temperature of 2000 K to 1700 K, rejecting heat at 1100 K to 700 K, while the AMTEC operates from a hot temperature of 1100 K to 900 K and a cold temperature of about 400 K. These temperature ranges form almost ideal cascade. {copyright} {ital 1996 American Institute of Physics.}

Miskolczy, G. [Thermo Trex Corp., 85 First Avenue, Waltham, Massachusetts 02254 (United States); Sievers, B.; Svedberg, B. [Advanced Modular Power Systems, Inc., 4667 Freedom Drive, Ann Arbor, Michigan 48108 (United States); Schuller, M. [Phillips Laboratory/VTPN, Kirtland Air Force Base, New Mexico 87117 (United States); VanHagen, T.; Smith, J. [General Atomics, 3550 General Atomics Court, San Diego, California 92121-1194 (United States); Reiners, E.; LeMire, R. [ORION International Technologies, Inc., 6501 Americas Parkway NE, Suite 200, Albuquerque, New Mexico 87110 (United States)

1996-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


181

Pressure and composition effect on wax precipitation: Experimental data and model results  

SciTech Connect (OSTI)

Wax precipitation is often studied using the stock tank oil. However, precipitation may be very different in well tubing and production facilities due to the effects of pressure and composition. As an example, the cloudpoint temperature may decrease as much as 15 K from atmospheric pressure to the saturation pressure of 100 bar mostly due to the dissolution of light gases into the oil (i.e. due to composition changes). It is also often assumed that the addition of solvents such as C{sub 5} and C{sub 6} decreases the cloudpoint temperature. On the contrary, from our modeling results, we have found that the mixing of a crude with a solvent increases the cloudpoint temperature (i.e., enhances the wax precipitation). In this study, the cloudpoint temperature at live oil conditions and the amount of the precipitated wax at stock tank oil conditions are provided for three crudes. A modified multisolid wax precipitation model is used to study the effects of pressure and composition on wax precipitation. The modeling results reveal that an increase in methane and CO{sub 2} concentration decreases the cloudpoint temperature while an increase in C{sub 5} concentration increases the cloud point temperature.

Pan, H.; Firoozabadi, A.; Fotland, P.

1996-12-31T23:59:59.000Z

182

Management Challenges in Developing Performance Assessments and Effectively Communicating Their Results - 13612  

SciTech Connect (OSTI)

The end of the Cold War has left a legacy of approximately 37 million gallons of radioactive waste in the aging waste tanks at the Department of Energy's Savannah River Site (SRS). A robust program is in place to remove waste from these tanks, treat the waste to separate into a relatively small volume of high level waste and a large volume of low-level waste, and to actively dispose of the low-level waste on-site and close the cleaned waste tanks and associated ancillary structures. To support performance-based, risk-informed decision making, performance assessments have been developed for the low-level waste disposal facility and for the SRS Tank Farms. Although these performance assessments share many similar features, the nature of the hazards and associated containments differ. As a management team, we are challenged to effectively communicate both the similarities and differences of these performance assessments, how they should be used to support sound decision making for treatment, disposal and waste tank cleaning decisions, and in defending their respective assumptions to the regulatory community and the public but, equally important, to our own corporate decision makers and operations personnel. Effective development and defense of these performance assessments, and effective interpretation and communication of the results are key to making cost-effective, pragmatic decisions for the safe disposal of the low-level waste and stabilization and operational closure of the cleaned tanks and associated structures. This paper will focus on the importance and challenges in communicating key attributes, conclusions and operational implications within a company. (authors)

Thomas, Steve; Mahoney, Mark [Savannah River Remediations LLC, Building 705-1C, Savannah River Site, Aiken, SC 29808 (United States)] [Savannah River Remediations LLC, Building 705-1C, Savannah River Site, Aiken, SC 29808 (United States)

2013-07-01T23:59:59.000Z

183

Calculation of gain and luminescence spectra of quantum-cascade laser structures taking into account asymmetric emission line broadening  

SciTech Connect (OSTI)

The energy levels, wave functions, and matrix elements of optical dipole transitions are calculated numerically for superlattice quantum-cascade structures. The effect of spectral broadening on the shape of emission spectra is estimated and semiphenomenological asymmetric profiles of emission line broadening are proposed. It is shown that the electroluminescence spectra well agree with the calculated spontaneous recombination spectra. (lasers)

Ushakov, D V; Manak, I S [Belarusian State University, Minsk (Belarus); Kononenko, V K [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus)

2010-05-26T23:59:59.000Z

184

Cascading metallic gratings for broadband absorption enhancement in ultrathin plasmonic solar cells  

SciTech Connect (OSTI)

The incorporation of plasmonic nanostructures in the thin-film solar cells (TFSCs) is a promising route to harvest light into the nanoscale active layer. However, the light trapping scheme based on the plasmonic effects intrinsically presents narrow-band resonant enhancement of light absorption. Here we demonstrate that by cascading metal nanogratings with different sizes atop the TFSCs, broadband absorption enhancement can be realized by simultaneously exciting multiple localized surface plasmon resonances and inducing strong coupling between the plasmonic modes and photonic modes. As a proof of concept, we demonstrate of 66.5% in the photocurrent in an ultrathin amorphous silicon TFSC with two-dimensional cascaded gratings over the reference cell without gratings.

Wen, Long; Sun, Fuhe [Key Laboratory of Nanodevices and Applications-CAS and Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123 (China); Chen, Qin, E-mail: qchen2012@sinano.ac.cn [Key Laboratory of Nanodevices and Applications-CAS and Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123 (China); Peking University Shenzhen SOC Key Laboratory, PKU-HKUST Shenzhen-Hong Kong Institute, Hi-Tech Industrial Park South, Shenzhen 518057 (China)

2014-04-14T23:59:59.000Z

185

Collective Lamb shift of superradiant cascade emissions in an atomic ensemble  

E-Print Network [OSTI]

We calculate the collective Lamb shift of the cascade spontaneous emissions from an atomic ensemble driven by two-color classical fields. The correlated pair of photons (signal and idler) is generated by adiabatically driving the system with large-detuned light fields in four-wave-mixing condition. The signal photon from the upper transition of the diamond-type atomic levels is followed by the idler one which can be superradiant due to light-induced dipole-dipole interactions. We demonstrate that the collective Lamb shift of the idler photon is a cumulative effect of interaction energy, and investigate its dependence on a cylindrical geometry. Manipulating the collective frequency of cascade emissions enables frequency qubits that provide alternative robust elements in quantum network.

H. H. Jen

2015-01-21T23:59:59.000Z

186

Mode-locked terahertz quantum cascade laser by direct phase synchronization  

SciTech Connect (OSTI)

Mode-locking of a terahertz quantum cascade laser is achieved using multimode injection seeding. Contrary to standard methods that rely on gain modulation, here a fixed phase relationship is directly imprinted to the laser modes. In this work, we demonstrate the generation of 9 ps phase mode-locked pulses around 2.75 THz. A direct measurement of the emitted field phase shows that it results from the phase of the initial injection.

Maussang, K.; Maysonnave, J.; Jukam, N.; Freeman, J. R.; Cavalié, P.; Dhillon, S. S.; Tignon, J. [Laboratoire Pierre Aigrain, Ecole Normale Supérieure, CNRS (UMR 8551), Université P. et M. Curie, Université D. Diderot, 75005 Paris (France); Khanna, S. P.; Linfield, E. H.; Davies, A. G. [School of Electronic and Electrical Engineering, University of Leeds, Leeds LS9 2JT (United Kingdom); Beere, H. E.; Ritchie, D. A. [University of Cambridge, Cavendish Lab, Cambridge CB3 0HE (United Kingdom)

2013-12-04T23:59:59.000Z

187

Two Dimensional Integration of Ring Cavity Surface Emitting Quantum Cascade Lasers  

SciTech Connect (OSTI)

The continual improvements over the last fifteen years have made quantum cascade lasers reliable and versatile light sources in the mid infrared and the terahertz spectral regions. In this work we present our latest results regarding the implementation of these light sources for forming broad band emitting two-dimensional laser arrays. A spectral tuning range of 180 cm{sup -1} around the centered wavelength of 8.2 {mu}m could be shown.

Schwarzer, Clemens; Mujagic, Elvis; Zederbauer, Tobias; Detz, Hermann; Andrews, Aaron M.; Schrenk, Werner; Strasser, Gottfried [Institute for Solid State Electronics, Vienna University of Technology, 1040 Vienna (Austria); Yao Yu; Chen Jianxin; Gmachl, Claire [Department of Electrical Engineering, Princeton University, Princeton, NJ 08544 (United States)

2011-12-26T23:59:59.000Z

188

Topological Analysis and Mitigation Strategies for Cascading Failures in Power Grid Networks  

E-Print Network [OSTI]

Recently, there has been a growing concern about the overload status of the power grid networks, and the increasing possibility of cascading failures. Many researchers have studied these networks to provide design guidelines for more robust power grids. Topological analysis is one of the components of system analysis for its robustness. This paper presents a complex systems analysis of power grid networks. First, the cascading effect has been simulated on three well known networks: the IEEE 300 bus test system, the IEEE 118 bus test system, and the WSCC 179 bus equivalent model. To extend the analysis to a larger set of networks, we develop a network generator and generate multiple graphs with characteristics similar to the IEEE test networks but with different topologies. The generated graphs are then compared to the test networks to show the effect of topology in determining their robustness with respect to cascading failures. The generated graphs turn out to be more robust than the test graphs, showing the...

Pahwa, Sakshi; Schulz, Noel

2012-01-01T23:59:59.000Z

189

Conserved quantities and dual turbulent cascades in Anti-de Sitter spacetime  

E-Print Network [OSTI]

We consider the dynamics of a spherically symmetric massless scalar field coupled to general relativity in Anti--de Sitter spacetime in the small-amplitude limit. Within the context of our previously developed two time framework (TTF) to study the leading self-gravitating effects, we demonstrate the existence of two new conserved quantities in addition to the known total energy $E$ of the modes: The particle number $N$ and Hamiltonian $H$ of our TTF system. $H$ represents the next-order contribution after $E$ to the total ADM mass $M$. Simultaneous conservation of $E$ and $N$ implies that weak turbulent processes undergo dual cascades (direct cascade of $E$ and inverse cascade of $N$ or vice versa). This partially explains the observed dynamics of 2-mode initial data. In addition, conservation of $E$ and $N$ limits the region of phase space that can be explored within the TTF approximation and in particular rules out equipartion of energy among the modes for general initial data. Finally, we discuss possible effects of conservation of $N$ and $E$ on late time dynamics.

Alex Buchel; Stephen R. Green; Luis Lehner; Steve L. Liebling

2014-12-15T23:59:59.000Z

190

Conserved quantities and dual turbulent cascades in Anti-de Sitter spacetime  

E-Print Network [OSTI]

We consider the dynamics of a spherically symmetric massless scalar field coupled to general relativity in Anti--de Sitter spacetime in the small-amplitude limit. Within the context of our previously developed two time framework (TTF) to study the leading self-gravitating effects, we demonstrate the existence of two new conserved quantities in addition to the known total energy $E$ of the modes: The particle number $N$ and Hamiltonian $H$ of our TTF system. Simultaneous conservation of $E$ and $N$ implies that weak turbulent processes undergo dual cascades (direct cascade of $E$ and inverse cascade of $N$ or vice versa). This partially explains the observed dynamics of 2-mode initial data. In addition, conservation of $E$ and $N$ limits the region of phase space that can be explored within the TTF approximation and in particular rules out equipartion of energy among the modes for general initial data. Finally, we discuss possible effects of conservation of $N$ and $E$ on late time dynamics.

Alex Buchel; Stephen R. Green; Luis Lehner; Steven L. Liebling

2015-02-17T23:59:59.000Z

191

Investigation of cascade-type falling liquid-film along first wall of laser-fusion reactor  

Science Journals Connector (OSTI)

To protect the first wall of an inertia fusion reactor from extremely high heat flux, X-rays, alpha particles and fuel debris caused by a nuclear fusion reaction, a “cascade-type” falling liquid-film flow is proposed as a “liquid-wall” concept. The flow visualization experiment to investigate the feasibility of this liquid-wall concept has been conducted. The preliminary numerical simulation results suggest that the current cascade structure design should be improved because less thermal-mixing is expected. The cascade-type structure has, therefore, been redesigned. This new cascade-type first wall consists of a liquid reservoir which has a free-surface to maintain a constant water head in the rear, and connects to a slit composed of two plates, i.e., the first wall is connected to a slit which is partially made up of the first wall to begin with it. The numerical simulations were performed on the new cascade-type first wall and they show the stable liquid-film flow on it. Moreover, the POP (proof-of-principle) flow visualization experiments, which satisfy the Weber number coincident condition, are carried out using water as the working fluid. By comparing the numerical and experimental results, it was found that the liquid-film flow with 3–5 mm thickness could be stably established. According to these results for the new cascade-type first wall concept, it was confirmed that the coolant flow rate and the thickness of the liquid-film could be controlled if the Weber number coincident condition was satisfied.

T. Kunugi; T. Nakai; Z. Kawara; T. Norimatsu; Y. Kozaki

2008-01-01T23:59:59.000Z

192

Hydrothermal Heat Discharge In The Cascade Range, Northwestern United  

Open Energy Info (EERE)

Page Page Edit History Facebook icon Twitter icon » Hydrothermal Heat Discharge In The Cascade Range, Northwestern United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Hydrothermal Heat Discharge In The Cascade Range, Northwestern United States Details Activities (3) Areas (1) Regions (0) Abstract: Hydrothermal heat discharge in the Cascade Range includes the heat discharged by thermal springs, by "slightly thermal" springs that are only a few degrees warmer than ambient temperature, and by fumaroles. Thermal-spring heat discharge is calculated on the basis of chloride-flux measurements and geothermometer temperatures and totals ~ 240 MW in the U.S. part of the Cascade Range, excluding the transient post-1980 discharge

193

EA-1893: Canby Cascaded Geothermal Development System, Canby, California |  

Broader source: Energy.gov (indexed) [DOE]

93: Canby Cascaded Geothermal Development System, Canby, 93: Canby Cascaded Geothermal Development System, Canby, California EA-1893: Canby Cascaded Geothermal Development System, Canby, California Summary This EA will evaluate the environmental impacts of a proposal by Modoc Contracting Company to use DOE grant funds to fulfill its plan to expand its reliance on geothermal resources by producing more hot water and using it to produce power as well as thermal energy. The goal of the project is to complete a cascaded geothermal system that generates green power for the local community, provides thermal energy to support greenhouse and aquaculture operation, provide sustainable thermal energy for residential units, and eliminate the existing geothermal discharge to a local river. NOTE: NOTE: This EA has been cancelled.

194

Statistical analysis of cascading failures in power grids  

SciTech Connect (OSTI)

We introduce a new microscopic model of cascading failures in transmission power grids. This model accounts for automatic response of the grid to load fluctuations that take place on the scale of minutes, when optimum power flow adjustments and load shedding controls are unavailable. We describe extreme events, caused by load fluctuations, which cause cascading failures of loads, generators and lines. Our model is quasi-static in the causal, discrete time and sequential resolution of individual failures. The model, in its simplest realization based on the Directed Current description of the power flow problem, is tested on three standard IEEE systems consisting of 30, 39 and 118 buses. Our statistical analysis suggests a straightforward classification of cascading and islanding phases in terms of the ratios between average number of removed loads, generators and links. The analysis also demonstrates sensitivity to variations in line capacities. Future research challenges in modeling and control of cascading outages over real-world power networks are discussed.

Chertkov, Michael [Los Alamos National Laboratory; Pfitzner, Rene [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory

2010-12-01T23:59:59.000Z

195

Characterization of mid-infrared quantum cascade lasers  

E-Print Network [OSTI]

Quantum cascade lasers provide some of the highest output powers available for light in the mid-infrared range (from 3 to 8 m). As many of their applications require portability, designs that have a high wall-plug efficiency ...

Burghoff, David Patrick

2009-01-01T23:59:59.000Z

196

Cascading Goals and Objectives to Ensure Accountability and Action  

E-Print Network [OSTI]

Bristol-Myers Squibb Worldwide Beauty Care Group has adopted a methodology that is reaping benefits throughout the company. The underlying principle in cascading goals and objectives is that every employee is accountable for achieving any corporate...

Tarifi, M.; Bingham, P. R.

197

Spectroscopic detection of biological NO with a quantum cascade laser  

Science Journals Connector (OSTI)

Two configurations of a continuous wave quantum cascade distributed feedback laser-based gas sensor for the detection of ... of biomedical applications, have been investigated. The laser was operated at liquid ni...

L. Menzel; A.A. Kosterev; R.F. Curl; F.K. Tittel; C. Gmachl…

2001-05-01T23:59:59.000Z

198

Open-path ozone detection by quantum-cascade laser  

Science Journals Connector (OSTI)

Open-path ozone measurements performed by mid-IR differential absorption spectroscopy are reported. Ozone spectrum was taken by fast repetitive sweeping of a quantum-cascade laser wavelength over a spectral featu...

M. Taslakov; V. Simeonov; M. Froidevaux; H. van den Bergh

2006-03-01T23:59:59.000Z

199

Characterization and analysis of highly diagonal Terahertz Quantum Cascade Lasers  

E-Print Network [OSTI]

The as yet unattained milestone of room-temperature operation is essential for establishing Terahertz Quantum Cascade Lasers (THz QCLs) as practical sources of THz radiation. Temperature performance is hypothesized to be ...

Chan, Chun Wang Ivan

2010-01-01T23:59:59.000Z

200

Prototype Test Results of the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)  

E-Print Network [OSTI]

There are currently no experiments, either satellite or ground-based, that are sensitive to astrophysical gamma-rays at energies between 20 and 250 GeV. We are developing the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) to explore this energy range. STACEE will use heliostat mirrors at a solar research facility to collect Cherenkov light from extensive air showers produced by high energy gamma-rays. Here we report on the results of prototype test work at the solar facility of Sandia National Laboratories (Albuquerque, NM). The work demonstrates that the facility is suitable for use as an astrophysical observatory. In addition, using a full scale prototype of part of STACEE, we detected atmospheric Cherenkov radiation at energies lower than any other ground-based experiment to date.

STACEE Collaboration

1997-04-03T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Electroluminescence of quantum-dash-based quantum cascade laser structures  

SciTech Connect (OSTI)

We developed two mid-infrared quantum cascade structures based on InAs quantum dashes. The dashes were embedded either in AlInGaAs lattice-matched to InP or in tensile-strained AlInAs. The devices emit between 7 and 11 {mu}m and are a step forward in the development of quantum cascade lasers based on 3-D confined active regions.

Liverini, V.; Bismuto, A.; Nevou, L.; Beck, M.; Faist, J. [Institute of Quantum Electronics, ETH Zurich, 8092 (Switzerland); Wolfgang-Pauli-Str. 16, HPT F 11, Zurich, CH-8093 (Switzerland)

2011-12-23T23:59:59.000Z

202

LDRD final report on high power broadly tunable Mid-IR quantum cascade lasers for improved chemical species detection.  

SciTech Connect (OSTI)

The goal of our project was to examine a novel quantum cascade laser design that should inherently increase the output power of the laser while simultaneously providing a broad tuning range. Such a laser source enables multiple chemical species identification with a single laser and/or very broad frequency coverage with a small number of different lasers, thus reducing the size and cost of laser based chemical detection systems. In our design concept, the discrete states in quantum cascade lasers are replaced by minibands made of multiple closely spaced electron levels. To facilitate the arduous task of designing miniband-to-miniband quantum cascade lasers, we developed a program that works in conjunction with our existing modeling software to completely automate the design process. Laser designs were grown, characterized, and iterated. The details of the automated design program and the measurement results are summarized in this report.

Wanke, Michael Clement; Hudgens, James J.; Fuller, Charles T.; Samora, Sally; Klem, John Frederick; Young, Erik W.

2006-01-01T23:59:59.000Z

203

Solar-assisted auto-cascade heat pump cycle with zeotropic mixture R32/R290 for small water heaters  

Science Journals Connector (OSTI)

Abstract In this study, a novel solar-assisted auto-cascade heat pump cycle (SAHPC) operating with the zeotropic mixture of R32/R290 for small water heaters is proposed. In the SAHPC system, a cascade heat exchanger (CHEX) associated with a phase separator is used to achieve auto cascade cycle and enhance the overall system performance. The performances of the SAHPC are evaluated by using the developed mathematical model, and then compared with the conventional air-sourced heat pump cycle (CAHPC). Simulation results show the SAHPC has 4.23–9.85% and 4.37–9.68% improvements in COP and volumetric heating capacity compared with those of the CAHPC, respectively, under the same operating conditions. However, the improvement of performance of this novel cycle largely depends on the absorbing heat ratio and the zeotropic composition. It is expected that this new cycle will be beneficial to developing dual-source coupled heat pump applications.

Xiaolong Lv; Gang Yan; Jianlin Yu

2015-01-01T23:59:59.000Z

204

Heat flux dynamics in dissipative cascaded systems  

E-Print Network [OSTI]

We study the dynamics of heat flux in the thermalization process of a pair of identical quantum system that interact dissipatively with a reservoir in a {\\it cascaded} fashion. Despite the open dynamics of the bipartite system S is globally Lindbladian, one of the subsystems "sees" the reservoir in a state modified by the interaction with the other subsystem and hence it undergoes a non-Markovian dynamics. As a consequence, the heat flow exhibits a non-exponential time behaviour which can greatly deviate from the case where each party is independently coupled to the reservoir. We investigate both thermal and correlated initial states of $S$ and show that the presence of correlations at the beginning can considerably affect the heat flux rate. We carry out our study in two paradigmatic cases -- a pair of harmonic oscillators with a reservoir of bosonic modes and two qubits with a reservoir of fermionic modes -- and compare the corresponding behaviours. In the case of qubits and for initial thermal states, we find that the trace distance discord is at any time interpretable as the correlated contribution to the total heat flux.

Salvatore Lorenzo; Alessandro Farace; Francesco Ciccarello; G. Massimo Palma; Vittorio Giovannetti

2014-12-19T23:59:59.000Z

205

Proton heating by parallel Alfven wave cascade  

SciTech Connect (OSTI)

In a recent series of papers, the present authors developed a kinetic theory for low-frequency turbulence propagating parallel to the ambient magnetic field. Making use of this theory, it was shown that low-frequency Alfvenic turbulence may cascade to ion-cyclotron frequency range and beyond by nonlinear three-wave decay processes. The significance of such a finding is that it may lead to the proton heating by cyclotron resonance. However, the actual proton heating process was not demonstrated. The present paper complements the previous works by including the proton heating in the discussion. It is found that the left-hand circularly polarized Alfven-cyclotron turbulence leads to a moderate heating of the protons in the perpendicular direction and cooling in the parallel direction. It is also found that ion-acoustic turbulence is generated by the decay instability process. Finally, the heating rate is shown to increase in inverse proportion to the time scale of the wave source.

Yoon, P. H.; Fang, T.-M. [Massachusetts Technological Laboratory, Inc., 330 Pleasant Street, Belmont, Massachusetts 02478 (United States)

2009-06-15T23:59:59.000Z

206

E-Print Network 3.0 - adhd synergistic effect Sample Search Results  

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an effective instrument in identifying individuals at high risk for ADHD (Adler et al. 2010). Boys... and effects of Adult Attention DeficitHyperactivity Disorder (ADHD) on the...

207

E-Print Network 3.0 - annual effective dose Sample Search Results  

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Dose Calculations For The Annual Environmental Surveillance Report Effective Date: 7112008 Next... ;Procedure No : SOP-5203 Revision: 0 Effective Date: 7112008...

208

Are there significant hydrothermal resources in the US part of the Cascade Range?  

SciTech Connect (OSTI)

The Cascade Range is a geothermal dichotomy. On the one hand, it is an active volcanic arc above a subducting plate and is demonstrably an area of high heat flow. On the other hand, the distribution of hydrothermal manifestations compared to other volcanic arcs is sparse, and the hydrothermal outflow calculated from stream chemistry is low. Several large estimates of undiscovered geothermal resources in the U.S. part of the Cascade Range prepared in the 1970s and early 1980s were based fundamentally on two models of the upper crust. One model assumed that large, partly molten, intrusive bodies exist in the upper 10 km beneath major volcanic centers and serve as the thermal engines driving overlying hydrothermal systems. The other model interpreted the coincident heat-flow and gravity gradients west of the Cascade crest in central Oregon to indicate a partly molten heat source at 10 {+-} 2 km depth extending {approx}30 km west from the axis of the range. Investigations of the past ten years have called both models into question. Large long-lived high-temperature hydrothermal systems at depths <3 km in the U.S. part of the Cascade Range appear to be restricted to silicic domefields at the Lassen volcanic center, Medicine Lake volcano, Newberry volcano, and possibly the Three Sisters. Federal land-use restrictions further reduce this list to Medicine Lake and Newberry. Dominantly andesitic stratocones appear to support only small transitory hydrothermal systems related to small intrusive bodies along the volcanic conduits. The only young caldera, at Crater Lake, supports only low- to intermediate-temperature hydrothermal systems. Most of the Cascade Range comprises basaltic andesites and has little likelihood for high-level silicic intrusions and virtually no potential for resultant large high-temperature hydrothermal systems. Undiscovered hydrothermal resources of the Cascade Range of the United States are substantially lower than previous estimates. The range does have potential for intermediate-temperature hot dry rock and localized low- to intermediate-temperature hydrothermal systems.

Muffler, L.J. Patrick; Guffanti, Marianne

1995-01-26T23:59:59.000Z

209

CONTROL OF POLLUTANT EMISSIONS IN NATURAL GAS DIFFUSION FLAMES BY USING CASCADE BURNERS  

SciTech Connect (OSTI)

The advanced CFDRC software package was installed on a SUN-SPARC dual processor workstation (UTPA funded). The literature pertinent to the project was collected. The physical model was set and all parameters and variables were identified. Based on the physical model, the geometric modeling and grid generation processes were performed using the CFD-GEOM (Interactive Geometric Modeling and Grid Generation software). A total number of 11160 cells (248 x 45) were generated. The venturis in the cascade were modeled as two-dimensional axisymmetric convergent nozzles around the jet. With the cascade being added to the jet, the geometric complexity of the problem increased; which required multi-domain structured grid systems to be connected and matched on the boundaries. The natural gas/propane jet diffusion flame is being numerically analyzed. The numerical computations are being conducted using the CFDRC-ACE+ (advanced computational environment) software package. The results are expected soon.

Ala Qubbaj

2001-03-30T23:59:59.000Z

210

Critical points and transitions in an electric power transmission model for cascading failure blackouts  

Science Journals Connector (OSTI)

Cascading failures in large-scale electric power transmission systems are an important cause of blackouts. Analysis of North American blackout data has revealed power law (algebraic) tails in the blackout size probability distribution which suggests a dynamical origin. With this observation as motivation we examine cascading failure in a simplified transmission system model as load power demand is increased. The model represents generators loads the transmission line network and the operating limits on these components. Two types of critical points are identified and are characterized by transmission line flow limits and generator capability limits respectively. Results are obtained for tree networks of a regular form and a more realistic 118-node network. It is found that operation near critical points can produce power law tails in the blackout size probability distribution similar to those observed. The complex nature of the solution space due to the interaction of the two critical points is examined.

B. A. Carreras; V. E. Lynch; I. Dobson; D. E. Newman

2002-01-01T23:59:59.000Z

211

Sb-free quantum cascade lasers in the 3–4 ?m spectral range  

Science Journals Connector (OSTI)

In this work, the design and implementation of Sb-free short wavelength strain-compensated quantum cascade lasers in the 3–4 ?m spectral range is presented. Due to the presence of highly strained AlAs-barrier layers, the optimization of the epitaxial growth process is firstly discussed. The used active region design is then presented together with the observed laser performance. Watt-level room temperature emission at 3.3 ?m is shown for Fabry–Perot devices and laser operation in pulsed mode is observed above 350 K. The laser performance is comparable with Sb-containing quantum cascade lasers. Spectral tuning of the lasers in an external cavity configuration over more than 275 cm?1 is achieved with an emission wavelength as short as 3.15 ?m. For the first time in this spectral range, results on single-mode buried heterostructure distributed feedback lasers are shown.

A Bismuto; S Riedi; B Hinkov; M Beck; J Faist

2012-01-01T23:59:59.000Z

212

Spontaneous current-layer fragmentation and cascading reconnection in solar flares: I. Model and analysis  

E-Print Network [OSTI]

Magnetic reconnection is commonly considered as a mechanism of solar (eruptive) flares. A deeper study of this scenario reveals, however, a number of open issues. Among them is the fundamental question, how the magnetic energy is transferred from large, accumulation scales to plasma scales where its actual dissipation takes place. In order to investigate this transfer over a broad range of scales we address this question by means of high-resolution MHD simulation. The simulation results indicate, that the magnetic-energy transfer to small scales is realized via a cascade of consecutive smaller and smaller flux-ropes (plasmoids), in analogy with the vortex-tube cascade in (incompressible) fluid dynamics. Both tearing and (driven) coalescence processes are equally important for the consecutive fragmentation of the magnetic field (and associated current density) to smaller elements. At the later stages a dynamic balance between tearing and coalescence processes reveals a steady (power-law) scaling typical for ca...

Bárta, Miroslav; Karlický, Marian; Skála, Jan

2010-01-01T23:59:59.000Z

213

The Energy Cascade from Warm Dark Matter Decays  

E-Print Network [OSTI]

We use a set of Monte Carlo simulations to follow the cascade produced by a primary electron of energy E_in in the intergalactic medium. We choose E_in=3-10 keV as expected from the decay of one of the most popular Warm Dark Matter (WDM) candidates, sterile neutrinos. Our simulation takes into account processes previously neglected such as free-free interactions with ions and recombinations and uses the best available cross sections for collisional ionizations and excitations with H and He and for electron-electron collisions. We precisely derive the fraction of the primary electron energy that heats the gas, ionizes atoms and produces line and continuum photons as a function of the ionization fraction. Handy fitting formulae for all the above energy depositions are provided. By keeping track of the individual photons we can distinguish between photons in the Ly-alpha resonance and those with energy E gas. This separation is important because a Ly-alpha background can heat or cool the gas depending on the nature of the photons, and can have effects on the 21 cm radiation emitted by neutral H, which will probably become detectable at z > 6 in the near future by the next generation radio interferometers.

M. Valdés; A. Ferrara

2008-03-04T23:59:59.000Z

214

Analysis and optimization of cascade Rankine cycle for liquefied natural gas cold energy recovery  

Science Journals Connector (OSTI)

Abstract This study proposes a new concept called the cascade Rankine cycle, which recovers LNG (liquefied natural gas) cold energy for power generation, optimizes the cycle by investigating the effects of key parameters on its performance, and compares its thermal efficiency, exergy efficiency and economic evaluation to those of the conventional alternatives. The cascade Rankine cycle consists of multiple stages of the organic Rankine cycle in a layered structure in which the first stage encompasses the second one that, in turn, encompasses the next. Due to its layered configuration, optimization of the cycle is straightforward and involves sequentially optimizing the individual stages. Optimization of the subsequent stages, however, required process simulation considering the equipment efficiency and the thermodynamic properties of the working fluid. Process simulation indicated that the indicators such as net power output, thermal efficiency, and exergy efficiency generally increase as the number of stages increases. These indicators were, however, significantly affected by the thermodynamic properties of the working fluids. The proposed cycles demonstrated significantly better performance in these indicators than the conventional cycles. The three-stage cascade Rankine cycle with propane as the working fluid exhibited the highest net power output, thermal efficiency and exergy efficiency within the set.

In-Hwan Choi; Sangick Lee; Yutaek Seo; Daejun Chang

2013-01-01T23:59:59.000Z

215

Kinetic cascade beyond magnetohydrodynamics of solar wind turbulence in two-dimensional hybrid simulations  

Science Journals Connector (OSTI)

The nature of solar windturbulence in the dissipation range at scales much smaller than the large magnetohydrodynamic (MHD) scales remains under debate. Here a two-dimensional model based on the hybrid code abbreviated as A.I.K.E.F. is presented which treats massive ions as particles obeying the kinetic Vlasov equation and massless electrons as a neutralizing fluid. Up to a certain wavenumber in the MHD regime the numerical system is initialized by assuming a superposition of isotropic Alfvén waves with amplitudes that follow the empirically confirmed spectral law of Kolmogorov. Then turbulence develops and energy cascades into the dispersive spectral range where also dissipative effects occur. Under typical solar wind conditions weak turbulence develops as a superposition of normal modes in the kinetic regime. Spectral analysis in the direction parallel to the background magnetic field reveals a cascade of left-handed Alfvén/ion-cyclotron waves up to wave vectors where their resonant absorption sets in as well as a continuing cascade of right-handed fast-mode and whistler waves. Perpendicular to the background field a broad turbulent spectrum is found to be built up of fluctuations having a strong compressive component. Ion-Bernstein waves seem to be possible normal modes in this propagation direction for lower driving amplitudes. Also signatures of short-scale pressure-balanced structures (very oblique slow-mode waves) are found.

D. Verscharen; E. Marsch; U. Motschmann; J. Müller

2012-01-01T23:59:59.000Z

216

Building America Whole-House Solutions for Existing Homes: Cascade Apartments- Deep Energy Multifamily Retrofit (Fact Sheet)  

Broader source: Energy.gov [DOE]

In December of 2009-10, King County Housing Authority implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington, which resulted in annual energy cost savings of 22%, improved comfort and air quality for residents, and increased durability of the units.

217

E-Print Network 3.0 - adult rats effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1995 Summary: Society of New Zealand 1995 291 Ranging behaviour of forest-dwelling ship rats, Rattus rattus, and effects... second aim was to investigate the effect of the...

218

E-Print Network 3.0 - average effective dose Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

effective dose Page: << < 1 2 3 4 5 > >> 1 A Unified Framework for PoC and Dose Estimation with Summary: of dose effect Four questions (Ruberg, 1995): 1.Is there any evidence...

219

Role of collisional broadening in Monte Carlo simulations of terahertz quantum cascade lasers  

SciTech Connect (OSTI)

Using a generalized version of Fermi's golden rule, collisional broadening is self-consistently implemented into ensemble Monte Carlo carrier transport simulations, and its effect on the transport and optical properties of terahertz quantum cascade lasers is investigated. The inclusion of broadening yields improved agreement with the experiment, without a significant increase of the numerical load. Specifically, this effect is crucial for a correct modeling at low biases. In the lasing regime, broadening can lead to significantly reduced optical gain and output power, affecting the obtained current-voltage characteristics.

Matyas, Alpar; Lugli, Paolo; Jirauschek, Christian [Institute for Nanoelectronics, Technische Universitaet Muenchen, D-80333 Munich (Germany)] [Institute for Nanoelectronics, Technische Universitaet Muenchen, D-80333 Munich (Germany)

2013-01-07T23:59:59.000Z

220

The conservative cascade of kinetic energy in compressible turbulence  

E-Print Network [OSTI]

The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We present the first direct evidence that mean kinetic energy cascades conservatively beyond a transitional "conversion" scale-range despite not being an invariant of the compressible flow dynamics. We use high-resolution three-dimensional simulations of compressible hydrodynamic turbulence on $512^3$ and $1024^3$ grids. We probe regimes of forced steady-state isothermal flows and of unforced decaying ideal gas flows. The key quantity we measure is pressure dilatation cospectrum, $E^{PD}(k)$, where we provide the first numerical evidence that it decays at a rate faster than $k^{-1}$ as a function of wavenumber. This is sufficient to imply that mean pressure dilatation acts primarily at large-scales and that kinetic and internal energy budgets statistically decouple beyond a transitional scale-range. Our results suggest that an extension of Kolmogorov's inertial-range theory to compressible turbulence is possible.

Hussein Aluie; Shengtai Li; Hui Li

2011-07-28T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

The conservative cascade of kinetic energy in compressible turbulence  

E-Print Network [OSTI]

The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We present the first direct evidence that mean kinetic energy cascades conservatively beyond a transitional "conversion" scale-range despite not being an invariant of the compressible flow dynamics. We use high-resolution three-dimensional simulations of compressible hydrodynamic turbulence on $512^3$ and $1024^3$ grids. We probe regimes of forced steady-state isothermal flows and of unforced decaying ideal gas flows. The key quantity we measure is pressure dilatation cospectrum, $E^{PD}(k)$, where we provide the first numerical evidence that it decays at a rate faster than $k^{-1}$ as a function of wavenumber. This is sufficient to imply that mean pressure dilatation acts primarily at large-scales and that kinetic and internal energy budgets statistically decouple beyond a transitional scale-range. Our results suggest that an extension of Kolmogorov's inertial-range theory to compressible turbu...

Aluie, Hussein; Li, Hui

2011-01-01T23:59:59.000Z

222

Fundamental Frequency Switching Control of Seven-Level Hybrid Cascaded H-bridge Multilevel Inverter  

SciTech Connect (OSTI)

This paper presents a cascaded H-bridge multilevel inverter that can be implemented using only a single dc power source and capacitors. Standard cascaded multilevel inverters require n dc sources for 2n + 1 levels. Without requiring transformers, the scheme proposed here allows the use of a single dc power source (e.g., a battery or a fuel cell stack) with the remaining n-1 dc sources being capacitors, which is referred to as hybrid cascaded H-bridge multilevel inverter (HCMLI) in this paper. It is shown that the inverter can simultaneously maintain the dc voltage level of the capacitors and choose a fundamental frequency switching pattern to produce a nearly sinusoidal output. HCMLI using only a single dc source for each phase is promising for high-power motor drive applications as it significantly decreases the number of required dc power supplies, provides high-quality output power due to its high number of output levels, and results in high conversion efficiency and low thermal stress as it uses a fundamental frequency switching scheme. This paper mainly discusses control of seven-level HCMLI with fundamental frequency switching control and how its modulation index range can be extended using triplen harmonic compensation.

Du, Zhong [ORNL; Chiasson, John N [ORNL; Ozpineci, Burak [ORNL; Tolbert, Leon M [ORNL

2009-01-01T23:59:59.000Z

223

E-Print Network 3.0 - atomic physics effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

photoionization of ground-state atoms. The physical basis... effects. Schemes for quantum logic gates using ultracold Rydberg ... Source: Killian, Thomas C. - Department of Physics...

224

E-Print Network 3.0 - aharonov-bohm effect Sample Search Results  

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it to the Aharonov-Bohm effect withan electromagnetic scalar potential. First we review the nonclassical nature... . that modular momentum provides a dynamical description of...

225

E-Print Network 3.0 - association iv effect Sample Search Results  

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, we have now examined the effect of the leader sequence of cytochrome ... Source: Brand, Paul H. - Department of Physiology and Pharmacology, University of Toledo...

226

E-Print Network 3.0 - abc effect Sample Search Results  

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University Collection: Biology and Medicine 3 Strategy of Experimentation II Computer Code. Summary: , and can estimate 2k -2p unconfounded effects. For this set up we have...

227

E-Print Network 3.0 - anomalous skin effect Sample Search Results  

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skin detector. Row 2(a) illustrates the effect of occlusion and rotational... Skin Patch Detection in Real-World Images Hannes Kruppa, Martin A. Bauer and Bernt Schiele... :...

228

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Effect, Wiley, New York, 1982, p. 400. 21 A. Gurevich, Phys... Generation of tunable terahertz radiation using Josephson vortices: ... Source: Nori, Franco - Institute for...

229

E-Print Network 3.0 - amoeba effect Sample Search Results  

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the edge-enhancing effect may be less pronounced with the amoeba filter than with self-snakes. The second... Differential Equations for Morphological Amoebas Martin Welk, Michael...

230

E-Print Network 3.0 - air guiding effect Sample Search Results  

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in voter... for the project in order to effectively improve air quality. Including air pollution as a screening criterion... reasons to consider air quality when ... Source:...

231

E-Print Network 3.0 - acute health effects Sample Search Results  

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; effects of context on health and health-related behavior; disparities in children's health care access... College of Health and Human Development Faculty Research Themes May...

232

E-Print Network 3.0 - aerosol trapping effect Sample Search Results  

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of this infrared radiation is trapped... 'S TEMPERATURE IS RISING This is the greenhouse effect. Without it, the Earths climate would be ... Source: Brookhaven National...

233

Broadening and splitting of emission spectra of a GaInAs/AlInAs quantum cascade laser in a quantising magnetic field  

SciTech Connect (OSTI)

We have studied the effect of a relatively weak quantising magnetic field on emission spectra of a GaInAs/AlInAs quantum cascade laser near 10 K. The results demonstrate that, as the magnetic field induction increases to 7 T, the spectra broaden (to 5 meV) and split into three emission bands. As a result, we observe simultaneously up to 80 longitudinal lasing modes in the three bands and the integrated laser output intensity increases 70 times. The presence of bands in the emission spectra can be accounted for in terms of the magnetic quantisation of the laser levels into spinsplit Landau levels. The increase in emission intensity is attributable primarily to phonon resonance adjustment in a magnetic field. (lasers)

Zasavitskii, I I; Pashkeev, D A; Bushuev, E V; Mikaelyan, G T

2013-02-28T23:59:59.000Z

234

Canby Cascaded Project Geothermal Project | Open Energy Information  

Open Energy Info (EERE)

Canby Cascaded Project Geothermal Project Canby Cascaded Project Geothermal Project Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Development Project: Canby Cascaded Project Geothermal Project Project Location Information Coordinates 41.443888888889°, -120.87027777778° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.443888888889,"lon":-120.87027777778,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

235

Cascade Natural Gas - Commercial Efficiency Rebate Program | Department of  

Broader source: Energy.gov (indexed) [DOE]

Cascade Natural Gas - Commercial Efficiency Rebate Program Cascade Natural Gas - Commercial Efficiency Rebate Program Cascade Natural Gas - Commercial Efficiency Rebate Program < Back Eligibility Commercial Industrial Savings Category Heating & Cooling Commercial Heating & Cooling Heating Home Weatherization Commercial Weatherization Appliances & Electronics Sealing Your Home Design & Remodeling Windows, Doors, & Skylights Water Heating Program Info State District of Columbia Program Type Utility Rebate Program Rebate Amount HVAC Unit Heater: $1.50-$3 / kBtuh input Warm Air Furnace: $3.00 / kBtuh input Direct Fired Radiant Heating: $6.50 / kBtuh input Boiler: $4.00 / kBtuh input Boiler Vent Damper: $1,000 Boiler Steam Trap: $80 DHW Energy Star Tankless Water Heaters: $60 / gpm Domestic Hot Water Tank: $2.50 / kBtuh input

236

Role of second trials in cascades of information over networks  

Science Journals Connector (OSTI)

We study the propagation of information in social networks. To do so, we focus on a cascade model where nodes are infected with probability p1 after their first contact with the information and with probability p2 at all subsequent contacts. The diffusion starts from one random node and leads to a cascade of infection. It is shown that first and subsequent trials play different roles in the propagation and that the size of the cascade depends in a nontrivial way on p1, p2, and on the network structure. Second trials are shown to amplify the propagation in dense parts of the network while first trials are dominant for the exploration of new parts of the network and launching new seeds of infection.

C. de Kerchove; G. Krings; R. Lambiotte; P. Van Dooren; V. D. Blondel

2009-01-30T23:59:59.000Z

237

The Cumulative Ecological Effects of Normal Offshore Petroleum Operations Contrasted With Those Resulting From Continental Shelf Oil Spills [and Discussion  

Science Journals Connector (OSTI)

...Ecological Effects of Normal Offshore Petroleum Operations Contrasted...Resulting From Continental Shelf Oil Spills [and Discussion...from normal (non-spill) offshore petroleum operations have...studies of spills of crude oil and its refined products...

1982-01-01T23:59:59.000Z

238

E-Print Network 3.0 - aqueous solution effect Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

, and solvent effects on solute structure and reactivity in aqueous and non-aqueous solvents and at complex... .g., as atomic par tial char ges. The SM8T model per mits...

239

The Effect of Ethical Signals on Recruitment Outcomes: Two Studies with Convergent Results  

E-Print Network [OSTI]

to communicate information regarding the organizational culture and environment. Drawing on signaling theory, this research suggests that ethical signals during the recruitment process affect recruitment outcomes through the mediating effect of the perception...

Degrassi, Sandra W.

2010-10-12T23:59:59.000Z

240

E-Print Network 3.0 - argon combined effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

University of California at San Diego Collection: Plasma Physics and Fusion 17 Ambient gas effects on the dynamics of laser-produced tin plume expansion Summary: ions can be...

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

E-Print Network 3.0 - atomic contacts effect Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

zero net 12;5 effect on the atomic momentum. Thus the force from ab- sorption... Laser cooling and trapping of atoms H.J. Metcalf and P. van der Straten ... Source: van der...

242

E-Print Network 3.0 - auger effect Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

11 Milagro Magic Paint: Does it Work? Summary: wavelengths ... i.e. an inverse greenhouse effect John MatthewsAuger North MeetingCSUFeb. 17-19, 2009 - p.6... of New Mexico...

243

E-Print Network 3.0 - audiovisual tau effect Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 IEEE TRANSACTIONS ON MULTIMEDIA, VOL. 11, NO. 5, AUGUST 2009 843 Human Perception of Audio-Visual Synthetic Summary: with respect to their effect on human perception and through...

244

On the Origin of Large Interstitial Clusters in Displacement Cascades  

SciTech Connect (OSTI)

Displacement cascades with wide ranges of primary knock-on atom (PKA) energy and mass in iron were simulated using molecular dynamics. New visualisation techniques are introduced to show how the shock-front dynamics and internal structure of a cascade develop over time. These reveal that the nature of the final damage is determined early on in the cascade process. We define a zone (termed 'spaghetti') in which atoms are moved to new lattice sites and show how it is created by a supersonic shock-front expanding from the primary recoil event. A large cluster of self-interstitial atoms can form on the periphery of the spaghetti if a hypersonic recoil creates damage with a supersonic shock ahead of the main supersonic front. When the two fronts meet, the main one injects atoms into the low-density core of the other: these become interstitial atoms during the rapid recovery of the surrounding crystal. The hypersonic recoil occurs in less than 0.1 ps after the primary recoil and the interstitial cluster is formed before the onset of the thermal spike phase of the cascade process. The corresponding number of vacancies is then formed in the spaghetti core as the crystal cools, i.e. at times one to two orders of magnitude longer. By using the spaghetti zone to define cascade volume, the energy density of a cascade is shown to be almost independent of the PKA mass. This throws into doubt the conventional energy-density interpretation of an increased defect yield with increasing PKA mass in ion irradiation.

Andrew, Calder F [University of Liverpool; Barashev, Aleksandr [University of Liverpool; Bacon, David J [University of Liverpool; Osetskiy, Yury N [ORNL

2010-01-01T23:59:59.000Z

245

Atomic Cascade in Muonic and Hadronic Hydrogen Atoms  

E-Print Network [OSTI]

The atomic cascade in $\\mu^- p$ and $\\pi^- p$ atoms has been studied with the improved version of the extended cascade model in which new quantum mechanical calculations of the differential and integral cross sections of the elastic scattering, Stark transitions and Coulomb de-excitation have been included for the principal quantum number values $n\\le 8$ and the relative energies $E \\ge 0.01$ eV. The $X$-ray yields and kinetic energy distributions are compared with the experimental data.

T. S. Jensen; V. P. Popov; V. N. Pomerantsev

2007-12-18T23:59:59.000Z

246

Ultrafast population dynamics in electrically modulated terahertz quantum cascade lasers  

Science Journals Connector (OSTI)

The ultrafast population dynamics in electrically modulated three-well terahertz quantum cascade lasers (QCLs) is studied by using the self-consistent Bloch–Poisson equations. In the modulation process, the non-equilibrium oscillations of the population inversion are found before the population equilibrium recovers. The equilibrium formation time increases nonlinearly with the period number. This phenomenon stems from the non-uniform distribution of the electric potential. In different periods, different responses to the electrical modulation are also explored. An in-depth understanding of electron transport in the cascade structure is obtained. Finally, we demonstrate the feasibility of a modulation frequency up to gigahertz in terahertz QCLs.

F Wang; X G Guo; C Wang; J C Cao

2013-01-01T23:59:59.000Z

247

Active-region designs in quantum cascade lasers  

SciTech Connect (OSTI)

This paper analyses the development of active-region designs in quantum cascade lasers. Active-region designs have been demonstrated to date that employ various radiative transitions (vertical, diagonal, interminiband and interband). The lower laser level is depopulated through nonradiative transitions, such as one- or two-phonon (and even three-phonon) relaxation or bound state {yields} continuum transitions. Advances in active-region designs and energy diagram optimisation in the past few years have led to significant improvements in important characteristics of quantum cascade lasers, such as their output power, emission bandwidth, characteristic temperature and efficiency. (invited paper)

Zasavitskii, I I [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2012-10-31T23:59:59.000Z

248

Standoff Hyperspectral Imaging of Explosives Residues Using Broadly Tunable External Cavity Quantum Cascade Laser Illumination  

SciTech Connect (OSTI)

We describe experimental results on the detection of explosives residues using active hyperspectral imaging by illumination of the target surface using an external cavity quantum cascade laser (ECQCL) and imaging using a room temperature microbolometer camera. The active hyperspectral imaging technique forms an image hypercube by recording one image for each tuning step of the ECQCL. The resulting hyperspectral image contains the full absorption spectrum produced by the illumination laser at each pixel in the image which can then be used to identify the explosive type and relative quantity using spectral identification approaches developed initially in the remote sensing community.

Bernacki, Bruce E.; Phillips, Mark C.

2010-05-01T23:59:59.000Z

249

E-Print Network 3.0 - alpha particle effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to mirror machines can benefit this concept by efficiently redirecting alpha particle energy... -transverse wave propagation. As a result, modes suitable for alpha particle...

250

E-Print Network 3.0 - aspect ratio effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

time scale of the resulting motion. In both series the initial aspect ratio a... two orders of magnitude. The initial basal lengths and range of aspect ... Source: Huppert,...

251

E-Print Network 3.0 - acute lead effects Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sciences ; Materials Science 2 Lexically Suggest, Logically Define: Quality Assurance of the Use of Qualifiers and Expected Results of Post-Coordination in Summary: and...

252

Slepton Discovery in Electroweak Cascade Decay  

E-Print Network [OSTI]

The LHC studies on the MSSM slepton sector have mostly been focused on direct slepton Drell-Yan pair production. In this paper, we analyze the case when the sleptons are lighter than heavy neutralinos and can appear in the on-shell decay of neutralino states. In particular, we have studied the \\chi_1^\\pm \\chi_2^0 associated production, with the consequent decays of \\chi_1^\\pm and \\chi_2^0 via on-shell sleptons. The invariant mass of the lepton pairs, m_{\\ell\\ell}, from the neutralino decay has a distinctive triangle shape with a sharp kinematic cutoff. We discuss the utilization of this triangle shape in m_{\\ell\\ell} distribution to identify the slepton signal. We studied the trilepton plus missing E_T signal and obtained the effective cross section, \\sigma \\times BR \\times acceptance, that is needed for a 5\\sigma discovery as a function of the cutoff mass for the LHC with center of mass energy 14 TeV and 100 fb^{-1} integrated luminosity. Our results are model independent such that they could be applied to other models with similar decay topology. When applied to the MSSM under simple assumptions, it is found that with 100 fb^{-1} integrated luminosity, a discovery reach in the left-handed slepton mass of about 600 GeV could be reached, which extends far beyond the slepton mass reach in the usual Drell-Yan studies.

Jonathan Eckel; William Shepherd; Shufang Su

2011-11-10T23:59:59.000Z

253

Effect of the reactor antineutrino anomaly on the first Double-Chooz results  

Science Journals Connector (OSTI)

We investigate the possible effects of short-baseline ?¯e disappearance implied by the reactor antineutrino anomaly on the Double-Chooz determination of ?13 through the normalization of the initial antineutrino flux with the Bugey-4 measurement. We show that the effects are negligible and the value of ?13 obtained by the Double-Chooz collaboration is accurate only if ?m412?3??eV2. For smaller values of ?m412 the short-baseline oscillations are not fully averaged at Bugey-4 and the uncertainties due to the reactor antineutrino anomaly can be of the same order of magnitude of the intrinsic Double-Chooz uncertainties.

Carlo Giunti and Marco Laveder

2012-02-08T23:59:59.000Z

254

Cascaded spin motive force driven by the dynamics of the skyrmion lattice  

SciTech Connect (OSTI)

We numerically investigate the spin motive force (SMF) driven by the dynamics of a Skyrmion lattice. The rotating mode of the Skyrmion core excited by the AC magnetic field induces the large spin-dependent electric field near the core. Due to the collective dynamics of Skyrmion lattice, the measurable voltage is enhanced by the cascade effect of the SMF. The amplitude of the AC voltage is estimated to 30??V in a macroscopic sample, where 100 Skyrmions exist between two probes. We also investigate the SMF due to the dynamics of the helical magnetic state, where the enhancement of the SMF does not occur.

Ohe, Jun-ichiro; Shimada, Yuhki [Department of Physics, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510 (Japan)] [Department of Physics, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510 (Japan)

2013-12-09T23:59:59.000Z

255

E-Print Network 3.0 - atmospheric neutrino-induced cascades Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fly's Eye Project Collection: Physics 6 SEARCH FOR NEUTRINO-INDUCED CASCADES FROM GAMMA-RAY BURSTS WITH AMANDA A. Achterberg,1 Summary: SEARCH FOR NEUTRINO-INDUCED CASCADES FROM...

256

Cascaded H-Bridge MV Grid and Power Balance Control for PV Systems  

Science Journals Connector (OSTI)

In this paper, a new centralized cascaded H-bridge medium-voltage (MV) grid topology model ... array partial shading or module mismatch of Cascaded H-Bridge is analyzed as well, based on which ... quality, solves...

Bin Zhang; Zhiyun Bao; Donglai Zhang…

2014-01-01T23:59:59.000Z

257

Effects of testing conditions on conceptual survey results Lin Ding, Neville W. Reay, Albert Lee, and Lei Bao  

E-Print Network [OSTI]

Effects of testing conditions on conceptual survey results Lin Ding, Neville W. Reay, Albert Lee 2008; published 9 June 2008 Pre-testing and post-testing is a commonly used method in Physics Education and incentives in delivering conceptual tests can impact test results. However, it is difficult to control

Bao, Lei

258

The effect of performance-based research funding on output of R&D results in the Czech Republic  

Science Journals Connector (OSTI)

We have studied the effects of performance-based research funding introduced to the Czech (CZ) R&D system in 2008 on outputs of R&D results. We have analyzed annual changes in number of various types of publications and applications including ... Keywords: Bibliometrics, Citation analysis, Patent output, Performance-based research funding, R&D results output

Jiri Vanecek

2014-01-01T23:59:59.000Z

259

Orographic effects during winter cold air outbreaks over the Sea of Japan (East Sea): Results  

E-Print Network [OSTI]

scatterometer wind measurements, such as the wakes (vortex street) in the lee of peaks along the range. Our of the coastal topography on the surface wind field during outbreaks has not been investigated in de- tail equations, orographic effect, gap wind, rotating channel flow, Rossby adjustment, Sea of Japan, air

Scotti, Alberto

260

Roles of Urban Tree Canopy and Buildings in Urban Heat Island Effects: Parameterization and Preliminary Results  

E-Print Network [OSTI]

and Forecasting model and an urban canopy model (WRF-UCM). By parameterizing the effects of these natural surfaces alongside roadways and buildings, the modified WRF-UCM is used to in- vestigate how urban trees, soil longwave radiative trapping in urban street canyons. 1. Introduction Urbanization can alter local climate

Dickerson, Russell R.

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Estimating surface water risk at Oak Ridge National Laboratory: Effects of site conditions on modeling results  

SciTech Connect (OSTI)

Multiple source term and groundwater modeling runs were executed to estimate surface water {sup 90}Sr concentrations resulting from leaching of sludges in five 180,000 gallon Gunite{trademark} tanks at Oak Ridge National Laboratory. Four release scenarios were analyzed: (1) leaching of unstabilized sludge with immediate tank failure; (2) leaching of unstabilized sludge with delayed tank failure due to chemical degradation; (3) leaching of stabilized sludge with immediate tank failure; and (4) leaching of residual contamination out of the shells of empty tanks. Source terms and concentrations of {sup 90}Sr in the stream directly downgradient of the tanks were calculated under these release scenarios. The following conclusions were drawn from the results of the modeling: (1) small changes in soil path length resulted in relatively large changes in the modeled {sup 90}Sr concentrations in the stream; (2) there was a linear relationship between the amount of sludge remaining in a tank and the peak concentration of {sup 90}Sr in the stream; (3) there was a linear relationship between the cumulative {sup 90}Sr release from a tank and the peak concentration of {sup 90}Sr in the stream; (4) sludge stabilization resulted in significantly reduced peak concentrations of {sup 90}Sr in the stream; and (5) although radioactive decay of {sup 90}Sr during the period of tank degradation resulted in incrementally lower peak {sup 90}Sr concentrations in surface water than under the immediate tank failure scenarios these concentrations were equivalent under the two scenarios after about 90 years.

Curtis, A.H. III

1996-08-01T23:59:59.000Z

262

Measurements of linestrengths, N2-, Ar-, He- and self-broadening coefficients of acetylene in the ?4+?5 combination band using a cw quantum cascade laser  

Science Journals Connector (OSTI)

Abstract Linestrengths, N2-, Ar-, He- and self-broadening coefficients of acetylene have been measured at 296 K in the P branch of the ?4+?5 combination band for 25 rotational transitions. The effect of gas temperature is studied over 296–683 K for five transitions to allow the determination of the temperature dependent exponent n for N2- and Ar-broadening coefficients. These measurements were performed using a continuous-wave quantum cascade laser (cw-QCL) operating over 1253–1310 cm?1. Spectroscopic parameters were obtained by fitting absorption spectra using Voigt, Galatry and Rautian profiles. Linestrength and broadening results are compared with previous studies available in literature for the ?4+?5 combination band and other vibrational bands of acetylene.

Muhammad Bilal Sajid; Et-touhami Es-sebbar; Aamir Farooq

2014-01-01T23:59:59.000Z

263

Shear Viscosity to Entropy within a Parton Cascade  

E-Print Network [OSTI]

The shear viscosity is calculated by means of the perturbative kinetic partonic cascade BAMPS with CGC initial conditons for various saturation momentum scale Q_s. eta/s ~ 0.15 stays approximately constant when going from RHIC to LHC.

A. El; C. Greiner; Z. Xu

2007-06-28T23:59:59.000Z

264

Hybrid Cascaded Multilevel Inverter with PWM Control Method  

E-Print Network [OSTI]

162 Hybrid Cascaded Multilevel Inverter with PWM Control Method Haiwen Liu1 , Leon M. Tolbert1, 2 inverter with PWM method is presented in this paper. It consists of a standard 3-leg inverter (one leg for each phase) and H-bridge in series with each inverter leg. It can use only a single DC power source

Tolbert, Leon M.

265

Monitoring of ethylene by a pulsed quantum cascade laser  

E-Print Network [OSTI]

Monitoring of ethylene by a pulsed quantum cascade laser Damien Weidmann, Anatoliy A. Kosterev ethylene C2H4 concentrations by use of a rotational component of the fundamental 7 band. The laser.5960, 300.6320. 1. Introduction The detection of ethylene C2H4 at trace levels is important in a number

266

Superconducting cascade electron refrigerator M. Camarasa-Gomez,1  

E-Print Network [OSTI]

arranged in a symmetric configuration, i.e. S2IS1INIS1IS2, as displayed in Fig. 1(a). The structure) S2IS1 INIS1 IS2 cascade cooler geometry. The optional el- ements contained into the two dashed boxes

Paris-Sud XI, Université de

267

Unraveling the Mechanism of Cascade Reactions of Zincke Aldehydes  

Science Journals Connector (OSTI)

Unraveling the Mechanism of Cascade Reactions of Zincke Aldehydes ... ‡ Department of Chemistry, University of California, Irvine, 1102 Natural Sciences II, Irvine, California 92697-2025, United States ... The E/Z conformational preferences (gas phase and soln.), rotational barriers, and IR spectra of ?-oxo ketenes are also reported. ...

Robert S. Paton; Sarah E. Steinhardt; Christopher D. Vanderwal; K. N. Houk

2011-02-25T23:59:59.000Z

268

Optimizing protections against cascades in network systems: a modified binary  

E-Print Network [OSTI]

to the topology of an electricity infrastructure, i.e. the 380 kV Italian power transmission network. We only protection; line switching; cascading failure; differential evolution algorithm; multi-objective optimization protection (NP) by line switching, done automatically or by a system operator, following an attack

Paris-Sud XI, Université de

269

Optimal adaptive control of cascading power grid failures1 Version 2010-Dec-20  

E-Print Network [OSTI]

Optimal adaptive control of cascading power grid failures1 Version 2010-Dec-20 Daniel Bienstock Columbia University New York 1 Introduction Power grids have long been a source of interesting optimization, the central modeling ingredient is that power grids display cascading behavior. A cascade is the process

Bienstock, Daniel

270

Capacitor Voltage Control in a Cascaded Multilevel Inverter as a Static Var Generator  

E-Print Network [OSTI]

1 Capacitor Voltage Control in a Cascaded Multilevel Inverter as a Static Var Generator M. Li, J. N for a cascaded multilevel inverter to be used for static var compensation. Index Terms-- Multilevel Inverter, Static Var Generator (SVG), Cascade inverter. I. INTRODUCTION Multilevel inverters have gained much

Tolbert, Leon M.

271

Tunable External Cavity Interband Cascade Laser A. N. Chryssis, M. Dagenais  

E-Print Network [OSTI]

region with a tuning range of 300nm (208 cm-1 ). For comparison, a tunable quantum cascade laserTunable External Cavity Interband Cascade Laser A. N. Chryssis, M. Dagenais Photonics Switching be operated at TEC compatible temperatures. Interband Cascade (IC) lasers[2] , have shown exceptional

Dagenais, Mario

272

HARMONIC CASCADE FEL DESIGNS FOR LUX, A FACILTY FOR ULTRAFAST X-RAY SCIENCE  

E-Print Network [OSTI]

-electron laser (FEL) beamlines which use the har- monic cascade approach to produce coherent XUV & soft X-ray for an integrated system of ultrafast x-ray techniques and lasers, using laser-seeded harmonic cascade FEL's, rfHARMONIC CASCADE FEL DESIGNS FOR LUX, A FACILTY FOR ULTRAFAST X-RAY SCIENCE J. Corlett, W. Fawley

Wurtele, Jonathan

273

The critical tension in the Cascading DGP model  

E-Print Network [OSTI]

We study the behaviour of weak gravitational fields in the 6D Cascading DGP model using a bulk-based approach. To deal with the ambiguity in the thin limit of branes of codimension higher than one, we consider a specific regularization of the internal structure of the branes where the 5D brane can be considered thin with respect to the 4D one. We consider the solutions corresponding to pure tension sources on the 4D brane, and study perturbations at first order around these background solutions. We adopt a 4D scalar-vector-tensor decomposition, and focus on the scalar sector of perturbations. We show that, in a suitable 4D limit, the trace part of the 4D metric perturbations obeys a decoupled equation which suggests that it is a ghost for background tensions smaller than a critical tension, while it is a healthy field otherwise. We give a geometrical interpretation of the existence of the critical tension and of the reason why the relevant field is a ghost or not depending on the background tension. We however find a value of the critical tension which is different from the one already found in the literature. Differently from the results in the literature, our analysis implies that, choosing the background tension suitably, we can construct ghost-free models for any value of the free parameters of the theory. We suggest that the difference lies in the procedure used to evaluate the pillbox integration across the codimension-2 brane. We confirm the validity of our analysis by performing numerically the integration in a particular case where the solution inside the thick cod-2 brane is known exactly. We stress that the singular structure of the perturbation fields in the nested branes set-ups is very subtle, and that great care has to be taken when deriving the codimension-2 junction conditions.

Fulvio Sbisa'; Kazuya Koyama

2014-09-01T23:59:59.000Z

274

Assessment of fish health effects resulting from exposure to oil sands wastewater  

SciTech Connect (OSTI)

The objective of this study was to determine if oil sands wastewater had an effect on the general health and condition of hatchery raised rainbow trout (200 to 400 g). Effects were assessed based on a battery of physiological and biochemical indices and the physical condition of the fish. The trout were exposed to tailings water in the field and in a flow through system under laboratory conditions. The field tests were conducted in 1992 and 1993 in experimental ponds at Syncrude which contained fine tails covered with surface water, fine tails covered with tailings water, and a surface water control pond. The laboratory treatments included Mildred Lake tailings water, dyke drainage water, fractionated tailings pond water (acid fraction containing naphthenic acids), sodium naphthenate, recycle water from Suncor`s tailings pond, and a laboratory control. All body condition factors and blood parameters were normal in the field and laboratory exposed fish and there were no apparent differences between the fish exposed to the tailings water and controls.

Balch, G.C.; Goudey, J.S. [HydroQual Labs. Ltd., Calgary, Alberta (Canada); Birkholtz, D. [EnviroTest Labs. Ltd., Edmonton, Alberta (Canada); Van Meer, T.; MacKinnon, M. [Syncrude Canada Ltd., Fort McMurray, Alberta (Canada)

1995-12-31T23:59:59.000Z

275

Perform Tests and Document Results and Analysis of Oxide Layer Effects and Comparisons  

SciTech Connect (OSTI)

During the initial feasibility test using actual used nuclear fuel (UNF) cladding in FY 2012, an incubation period of 30–45 minutes was observed in the initial dry chlorination. The cladding hull used in the test had been previously oxidized in a dry air oxidation pretreatment prior to removal of the fuel. The cause of this incubation period was attributed to the resistance to chlorination of an oxide layer imparted by the dry oxidation pretreatment on the cladding. Subsequently in 2013, researchers at the Korea Atomic Energy Institute (KAERI) reported on their chlorination study [R1] on ~9-gram samples of unirradiated ZirloTM cladding tubes that had been previously oxidized in air at 500oC for various time periods to impart oxide layers of varying thickness. In early 2014, discussions with Indefinite Delivery, Indefinite Quantity (IDIQ) contracted technical consultants from Westinghouse described their previous development (and patents) [R2] on methods of chemical washing to remove some or all of the hydrous oxide layer imparted on UNF cladding during irradiation in light water reactors (LWRs) . Thus, the Oak Ridge National Laboratory (ORNL) study, described herein, was planned to extend the KAERI study on the effects of anhydrous oxide layers, but on larger ~100-gram samples of unirradiated zirconium alloy cladding tubes, and to investigate the effects of various methods of chemical pretreatment prior to chlorination with 100% chlorine on the average reaction rates and Cl2 usage efficiencies.

Collins, E. D. [ORNL; DelCul, G. D. [ORNL; Spencer, B. B. [ORNL; Hunt, R. D. [ORNL; Ausmus, C. [ORNL

2014-08-30T23:59:59.000Z

276

Equivalent circuit-level model and improvement of terahertz quantum cascade lasers  

Science Journals Connector (OSTI)

An equivalent circuit-level model of terahertz (THz) quantum cascade lasers (QCLs) is developed by using rate equations. This model can be employed to investigate the characteristics of THz QCLs accurately and to improve their design. We use the circuit-level model to analyse a new active structure, which can improve the performance of THz QCLs by means of enhancing carrier injection. The simulation result shows that THz QCLs with the new active structure have a much higher performance compared with conventional THz QCLs. The high-performance THz QCLs are expected to be operated at higher temperatures.

Wei Zhou; Shaobin Liu; Jie Wu; Xiaoliu Zhang; Wu Tang

2014-01-01T23:59:59.000Z

277

Angular correlation of K-L x-ray cascades in gadolinium  

Science Journals Connector (OSTI)

Angular correlation parameters (A22) between the K?1 and L3 x rays were measured for gadolinium in the electron-capture decay of the isotope Tb157. The results are A22(K?1-Ll)=0.272±0.042, A22(K?1-L?)=0.032±0.015, A22(K?1-L?2,15)=0.061±0.018. These values are in very good agreement with the theoretical calculations of Scofield [Lawrence Livermore Laboratory Report No. UCRL 51231, 1972 (unpublished)]; however, they differ from the earlier experimental data for the K?1-Ll cascade in the 60

T. Papp, J. L. Campbell, and S. Raman

1994-02-01T23:59:59.000Z

278

Magnetic fields in fast breeder reactors: New results on thermoelectricity and dynamo effects  

SciTech Connect (OSTI)

This paper deals with magnetic field calculations in Liquid Metal Fast Breeder Reactors (LMFBR) in order to give a quantitative estimation of the possible origins of magnetohydrodynamic instability. In the first part, following an estimation made by previous researchers, two improved methods aimed at calculating the magnetic field generated by thermoelectric currents flowing in the reactor are presented: although very different, both give similar results. In the second part, dynamo action is investigated for a Ponomarenko model with nonhomogeneous material properties, allowing a more realistic estimate of critical conditions for self-excitation in a LMFBR. The results confirm the decrease of the critical magnetic Reynolds number when the external medium has either a high electrical conductivity or a high magnetic permeability.

Marty, Ph.; Ajakh, A. [Centre National de la Recherche Scientifique, Grenoble (France); Thess, A. [Forschungszentrum, Dresden (Germany)

1995-04-01T23:59:59.000Z

279

Activation of the cyclic AMP cascade as an ocoggenic mechanism: The thyroid example  

Science Journals Connector (OSTI)

Three cascades activate thyroid cell proliferation: the EGF-protein tyrosine kinase pathway, the phorbol ester-protein kinase C pathway and the thyrotropin-cyclic AMP pathway. While the first cascades converge early, they remain distinct from the cyclic AMP cascade until very late in G1. The cyclic AMP cascade us characterized by an early and transient expression of c-myc, which may explain why it induces proliferation and differentiation expression. Constitutive activation of this cascade causes growth and hyperfunction, ie, hyperfunctioning adenomas. The various possible defects that could lead to such a constitutive activation are discussed.

C. Maenhaut; P.P. Roger; S. Reuse; J.E. Dumont

1991-01-01T23:59:59.000Z

280

Effects of thermomechanical processing on the resulting mechanical properties of 6101 aluminum foam  

SciTech Connect (OSTI)

Porous materials represent a tremendous weight savings for light-weight structural applications. The fabrication path can play a critical role in the resulting properties. High porosity aluminum was fabricated in a number of ways. The starting material was a cast 6101 aluminum that had a relative density of 9.8%. The cast aluminum block was compressed by uniaxial, biaxial, and triaxial densification. Uniaxial compression was done at room temperature and 200 C. Biaxial compression was achieved by unidirectional rolling at room temperature and 200 C. Triaxial compression was done by cold isostatic pressing at 3.4, 6.7, and 34 MPa (0.5, 1.0, and 5.0 ksi). Metallography and mechanical test specimens were machines from the processed bars. The mechanical properties showed that the relative yield strength depended both on relative density and processing temperature.

Margevicius, R.W.; Stanek, P.W.; Jacobson, L.A.

1998-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Poincare recurrence and spectral cascades in three-dimensional quantum turbulence  

SciTech Connect (OSTI)

The time evolution of the ground state wave function of a zero-temperature Bose-Einstein condensate (BEC) gas is well described by the Hamiltonian Gross-Pitaevskii (GP) equation. Using a set of appropriately interleaved unitary collision-stream operators, a qubit lattice gas algorithm is devised, which on taking moments, recovers the Gross-Pitaevskii (GP) equation under diffusion ordering (time scales as length{sup 2}). Unexpectedly, there is a class of initial states whose Poincare recurrence time is extremely short and which, as the grid resolution is increased, scales with diffusion ordering (and not as length{sup 3}). The spectral results of J. Yepez et al.[Phys. Rev. Lett. 103, 084501 (2009).] for quantum turbulence are revised and it is found that it is the compressible kinetic energy spectrum that exhibits three distinct spectral regions: a small-k classical-like Kolmogorov k{sup -5/3}, a steep semiclassical cascade region, and a large-k quantum vortex spectrum k{sup -3}. For most evolution times the incompressible kinetic energy spectrum exhibits a somewhat robust quantum vortex spectrum of k{sup -3} for an extended range in k with a k{sup -3.4} spectrum for intermediate k. For linear vortices of winding number 1 there is an intermittent loss of the quantum vortex cascade with its signature seen in the time evolution of the kinetic energy E{sub kin}(t), the loss of the quantum vortex k{sup -3} spectrum in the incompressible kinetic energy spectrum as well as the minimalization of the vortex core isosurfaces that would totally inhibit any Kelvin wave vortex cascade. In the time intervals around these intermittencies the incompressible kinetic energy also exhibits a multicascade spectrum.

Vahala, George; Zhang Bo [Department of Physics, William and Mary, Williamsburg, Virginia 23185 (United States); Yepez, Jeffrey [Air Force Research Laboratory, Hanscom Air Force Base, Massachusetts 01731 (United States); Vahala, Linda [Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States); Soe, Min [Department of Mathematics and Physical Sciences, Rogers State University, Claremore, Oklahoma 74017 (United States); Ziegeler, Sean [High Performance Technologies, Inc., Reston, Virginia 20190 (United States)

2011-10-15T23:59:59.000Z

282

Cascade-Chipita Park, Colorado: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Cascade-Chipita Park, Colorado: Energy Resources Cascade-Chipita Park, Colorado: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 38.9498727°, -105.0031457° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":38.9498727,"lon":-105.0031457,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

283

Cascade Apartments - Deep Energy Multifamily Retrofit , Kent, Washington (Fact Sheet)  

SciTech Connect (OSTI)

In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

Not Available

2014-02-01T23:59:59.000Z

284

Microsoft Word - Cascade Networks Allston Substation LURR CX.doc  

Broader source: Energy.gov (indexed) [DOE]

15, 2011 15, 2011 REPLY TO ATTN OF: KEC-4 SUBJECT: Environmental Clearence Memorandum Harold Grappe - TELP-TPP-3 Proposed Action: Cascade Networks, Inc. LURR at Allston Substation Budget Information: Work Order # 00275035 Task 03 Categorical Exclusions Applied (from Subpart D, 10 C.F.R. Part 1021: B1.7 "Acquisition, installation, operation, and removal of communication systems, data processing equipment, and similar electronic equipment." B4.7 "Adding fiber optic cable to transmission structures..." Location: Section 10, Township 7 North, Range 3 West of the Delena Quadrangle located in Columbia County, Oregon Proposed by: Bonneville Power Administration (BPA) Description of the Proposed Action: BPA proposes to grant Cascade Networks, Inc. permission to

285

Gain spectra and temperature characteristics of quantum cascade lasers  

Science Journals Connector (OSTI)

We have developed a theory describing the operation of lasers based on intersubband transitions in a quantum well. The theory combines a first-principles description of the intersubband lineshape and the optical gain with kinetic models for carrier heating. ... Keywords: carrier heating, gain spectra, intersubband lineshape, intersubband transitions, kinetic models, laser theory, optical gain, quantum cascade lasers, quantum well, quantum well lasers, room-temperature high-power operation, temperature characteristics

V. Gorfinkel; S. Luryi; B. Gelmont

1995-11-01T23:59:59.000Z

286

Deeply etched waveguide structures for quantum cascade lasers  

Science Journals Connector (OSTI)

A high density plasma process was developed for reactive ion etching (RIE) of GaAs/AlGaAs based devices which can be applied for the processing of advanced resonator designs. We present diffractive resonators fabricated using inductively coupled plasma ... Keywords: 42.55.Px, 42.55.Xi, 78.67.De, 81.65.Cf, Deep etching, Distributed feedback, Photonic crystals, Quantum cascade lasers

S. Schartner; S. Golka; C. Pflügl; W. Schrenk; G. Strasser

2006-04-01T23:59:59.000Z

287

Dual wavelength emission from a terahertz quantum cascade laser  

SciTech Connect (OSTI)

We describe a heterogeneous THz quantum cascade laser that is composed of two different active region designs. This device emits simultaneously at around 2.5 THz and 2.9 THz with a certain frequency tunability by applied current. We also investigate the spectral gain in the structure by THz time-domain spectroscopy and correlate the gain spectral bandwidth with the alignment and wavelength emission behaviour of the two stack device.

Freeman, Joshua R.; Brewer, Anthony; Marshall, Owen P.; Beere, Harvey E.; Ritchie, David A. [Semiconductor Physics, Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE (United Kingdom); Madeo, Julien; Dhillon, Sukhdeep; Jukam, Nathan; Oustinov, Dimitri; Tignon, Jerome [Laboratoire Pierre Aigrain, Ecole Normale Suprieure, UMR 8551 CNRS, UPMC Univ. Paris 6 75005 Paris (France)

2011-12-23T23:59:59.000Z

288

Unexpected Copper-Catalyzed Cascade Synthesis of Quinazoline Derivatives  

Science Journals Connector (OSTI)

Unexpected Copper-Catalyzed Cascade Synthesis of Quinazoline Derivatives ... Nitrogen-containing heterocycles are present in a wide variety of bioactive natural products and biological molecules that may be good drug candidates. ... To our surprise, the trace of unexpected 2-phenylquinazoline (3a) was observed by gas chromatography/mass spectrometry (electron ionization) [GC/MS (EI)] analysis during the process of performing the above condensation reaction in the presence of ceric ammonium nitrate (CAN). ...

Zhongyan Chen; Jiuxi Chen; Miaochang Liu; Jinchang Ding; Wenxia Gao; Xiaobo Huang; Huayue Wu

2013-10-17T23:59:59.000Z

289

A Thermal Cascade Route to Pyrroloisoindolone and Pyrroloimidazolones  

Science Journals Connector (OSTI)

A Thermal Cascade Route to Pyrroloisoindolone and Pyrroloimidazolones ... However, we have shown that pyrrolizin-3-ones 1 and related ring systems can be conveniently made in the gas phase by flash vacuum pyrolysis (FVP) of Meldrum's acid derivatives6,7 (“the Meldrum's route”) and by FVP of pyrrol-2-ylacrylate derivatives (“the C-acrylate route”). ... This always overrides the “natural” direction of migration in the unsubstituted ring system. ...

Hamish McNab; Richard G. Tyas

2007-10-19T23:59:59.000Z

290

Cascade heat recovery with coproduct gas production  

DOE Patents [OSTI]

A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange. 4 figs.

Brown, W.R.; Cassano, A.A.; Dunbobbin, B.R.; Rao, P.; Erickson, D.C.

1986-10-14T23:59:59.000Z

291

THz quantum cascade lasers for standoff molecule detection.  

SciTech Connect (OSTI)

Remote optical detection of molecules, agents, and energetic materials has many applications to national security interests. Currently there is significant interest in determining under what circumstances THz frequency coverage will aid in a complete sensing package. Sources of coherent THz frequency (i.e. 0.1 to 10 THz) electromagnetic radiation with requisite power levels, frequency agility, compactness and reliability represent the single greatest obstacle in establishing a THz technology base, but recent advances in semiconductor-based quantum cascade lasers (QCLs) offer huge improvements towards the ultimate THz source goals. This project advanced the development of narrow-linewidth THz quantum cascade lasers. We developed theoretical tools to guide the improvement of standard THz quantum cascade lasers, the investigation of nonlinear optics employing infrared QCLs, and the exploration of quantum coherence to improve QCL performance. The latter was aimed especially towards achieving high temperature operation. In addition we developed a computer algorithm capable of shifting the frequencies of an existing THz QCL to a different frequency and invented a new type of laser that may enable room temperature THz generation in a electrically driven solid-state source.

Chow, Weng Wah; Wanke, Michael Clement; Lerttamrab, Maytee; Waldmueller, Ines

2007-10-01T23:59:59.000Z

292

Kinetic cascade beyond MHD of solar wind turbulence in two-dimensional hybrid simulations  

E-Print Network [OSTI]

The nature of solar wind turbulence in the dissipation range at scales much smaller than the large MHD scales remains under debate. Here a two-dimensional model based on the hybrid code abbreviated as A.I.K.E.F. is presented, which treats massive ions as particles obeying the kinetic Vlasov equation and massless electrons as a neutralizing fluid. Up to a certain wavenumber in the MHD regime, the numerical system is initialized by assuming a superposition of isotropic Alfv\\'en waves with amplitudes that follow the empirically confirmed spectral law of Kolmogorov. Then turbulence develops and energy cascades into the dispersive spectral range, where also dissipative effects occur. Under typical solar wind conditions, weak turbulence develops as a superposition of normal modes in the kinetic regime. Spectral analysis in the direction parallel to the background magnetic field reveals a cascade of left-handed Alfv\\'en/ion-cyclotron waves up to wave vectors where their resonant absorption sets in, as well as a cont...

Verscharen, Daniel; Motschmann, Uwe; Müller, Joachim

2012-01-01T23:59:59.000Z

293

Effect of Bromide Ion on Haloacetic Acid Speciation Resulting from Chlorination and Chloramination of Aquatic Humic Substances  

Science Journals Connector (OSTI)

In addition to studying the effect of bromide ion on HAA speciation, this work included investigation of the effect of pH on HAA formation and speciation, comparison of the effect of chlorination and chloramination on HAA formation and speciation, and comparison of two different sources of natural organic material with respect to HAA formation and speciation. ... The ether layer was separated and derivatized with diazomethane, and the samples were then analyzed on an HP-5890 Series II gas chromatograph with electron capture detector (Hewlett-Packard, San Fernando, CA). ... The results of these analyses are given in Table 1 for finished waters from the Philadelphia (PA) Suburban Water Co. (PSWC), the Metropolitan Water District of Southern California (MWD), and the cities of Houston, TX, and Corpus Christi, TX. ...

Gretchen A. Cowman; Philip C. Singer

1995-12-27T23:59:59.000Z

294

Three-Phase Modular Cascaded H-Bridge Multilevel Inverter with Individual MPPT for Grid-Connected Photovoltaic Systems  

SciTech Connect (OSTI)

A three-phase modular cascaded H-bridge multilevel inverter for a grid-connected photovoltaic (PV) system is presented in this paper. To maximize the solar energy extraction of each PV string, an individual maximum power point tracking (MPPT) control scheme is applied, which allows the independent control of each dc-link voltage. PV mismatches may introduce unbalanced power supplied to the three-phase system. To solve this issue, a control scheme with modulation compensation is proposed. The three-phase modular cascaded multilevel inverter prototype has been built. Each H-bridge is connected to a 185 W solar panel. Simulation and experimental results are presented to validate the proposed ideas.

Xiao, Bailu [ORNL; Hang, Lijun [ORNL; Riley, Cameron [University of Tennessee, Knoxville (UTK); Tolbert, Leon M [ORNL; Ozpineci, Burak [ORNL

2013-01-01T23:59:59.000Z

295

THEORETICAL INVESTIGATION OF MICROSTRUCTURE EVOLUTION AND DEFORMATION OF ZIRCONIUM UNDER CASCADE DAMAGE CONDITIONS  

SciTech Connect (OSTI)

This work is based on our reaction-diffusion model of radiation growth of Zr-based materials proposed recently in [1]. In [1], the equations for the strain rates in unloaded pure crystal under cascade damage conditions of, e.g., neutron or heavy-ion irradiation were derived as functions of dislocation densities, which include contributions from dislocation loops, and spatial distribution of their Burgers vectors. The model takes into account the intra-cascade clustering of self-interstitial atoms and their one-dimensional diffusion; explains the growth stages, including the break-away growth of pre-annealed samples; and accounts for some striking observations, such as of negative strain in prismatic direction, and co-existence of vacancy- and interstitial-type prismatic loops. In this report, the change of dislocation densities due to accumulation of sessile dislocation loops is taken into account explicitly to investigate the dose dependence of radiation growth. The dose dependence of climb rates of dislocations is calculated, which is important for the climb-induced glide model of radiation creep. The results of fitting the model to available experimental data and some numerical calculations of the strain behavior of Zr for different initial dislocation structures are presented and discussed. The computer code RIMD-ZR.V1 (Radiation Induced Microstructure and Deformation of Zr) developed is described and attached to this report.

Barashev, Alexander V [ORNL; Golubov, Stanislav I [ORNL; Stoller, Roger E [ORNL

2012-06-01T23:59:59.000Z

296

Selection of potential IAEA inspection strategies involving cascade access at the Portsmouth Gas Centrifuge Enrichment Plant (GCEP)  

SciTech Connect (OSTI)

This report has been prepared as a US contribution to Team 4 of the Hexapartite Safeguards Project. It provides to the Team 4 participants one example of an approach, which has been used in the United States, to developing a range of safeguards strategies involving differing degrees of access to cascade areas of centrifuge enrichment plants. Its purpose is to facilitate the work of other Hexapartite participants in completing Task II of Team 4's terms of reference. The scope of this report is limited to identifying safeguards approaches for the Portsmouth Gas Centrifuge Enrichment Plant (GCEP) which involve differing degrees of access to the cascade area. This report provides a method for selecting cascade access inspection strategies at GCEP which appear promising for more detailed evaluation. It is quite important to note, however, that the effectiveness and practicability of these strategies have not been established at the present. In addition, some strategies have been included on the basis of very preliminary calculations and considerations which have not been validated. Thus, some of these strategies may ultimately be rejected because they prove to be impracticable. Considerations of cost and the possible transfer of information and technology related to the production of enriched uranium will also be pertinent in considering the degrees and frequency of access to the cascade areas of centrifuge enrichment plants. This report describes the process for combining technical measures, implementation approaches and objectives to arrive at the total number of theoretically possible combinations. It then describes how these combinations may be reduced in a series of steps to a number that is more manageable for detailed evaluation. The process is shown schematically.

Not Available

1981-04-13T23:59:59.000Z

297

Discrimination between 1/f noise models in junctions field effect transistors and metal?oxide?semiconductor field effect transistors: Numerical results  

Science Journals Connector (OSTI)

The integrals given by Park e t a l. in an earlier paper [J. Appl. Phys. 52 296 (1981)] on 1/f noise are expressed in closed forms and evaluated numerically. The results show how the field dependent mobility affects the number fluctuation model and how the field dependent mobility and the field dependence of Hooge’s parameter ? affects the mobility fluctuation model. The latter effect is very strong and results in a large decrease in the noise spectrum at larger values of drain bias when compared with the elementary theory that neglects these field dependences. For relatively short channels the mobility fluctuation model gives a peak in the noise well before saturation in agreement with the experiments of Park e t a l. The effects of the field dependent mobility and of the field dependent ? on the noise resistance at saturation are evaluated numerically.

A. van der Ziel; R. J. J. Zijlstra; H. S. Park

1981-01-01T23:59:59.000Z

298

Modernization of the guide bearings of turbines of the cascade of Chirchik hydroelectric stations  

Science Journals Connector (OSTI)

The favorable experience of reconstruction and subsequent operation of the guide bearings of turbines of the cascade of Chirchik hydrostations confirms the possibility of modernizing bearings under conditions ...

V. V. Balagurov; Yu. P. Maizel'; M. A. Tsvetkova…

1981-08-01T23:59:59.000Z

299

Faraday rotation spectroscopy of nitrogen dioxide based on a widely tunable external cavity quantum cascade laser  

E-Print Network [OSTI]

Faraday rotation spectroscopy of nitrogen dioxide based on a widely tunable external cavity quantum: Faraday Rotation Spectroscopy, external-cavity quantum cascade laser, nitrogen dioxide, trace

300

External Cavity Quantum Cascade Lasers: Recent Advances, Applications, and Comparisons with Alternative Sources in the MIR  

Science Journals Connector (OSTI)

The performance of external cavity quantum/interband cascade lasers (ECqcL/ECicL) in molecular detection and imaging applications will be discussed. Alternative MIR laser technologies...

Day, Timothy

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Limiting Factors for High Temperature Operation of THz Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We theoretically investigate the temperature dependence of the carrier transport in GaAs-based THz quantum cascade lasers and identify the factors restricting high-temperature...

Jirauschek, Christian; Lugli, Paolo

302

Quantum cascade laser spectrometer for trace-gas detection of exhaled Carbonyl Sulfide  

Science Journals Connector (OSTI)

Simultaneous concentration measurements of exhaled carbonyl sulfide and carbon dioxide were demonstrated using a pulsed quantum cascade laser based gas sensor. This sensor has...

Wysocki, Gerard; So, Stephen; McCurdy, Matt; Roller, Chad; Weidmann, Damien; Kosterev, Anatoliy a; Frantz, J Patrick; Curl, Robert F; Tittel, Frank K

303

THz Quantum Cascade Lasers Grown by Low-Pressure Metalorganic Vapor Phase Epitaxy  

Science Journals Connector (OSTI)

A terahertz quantum cascade laser (QCL) has been successfully grown by low-pressure MOVPE. Very high quality semiconductor interfaces are demonstrated as well as very promising lasing...

Sirigu, Lorenzo; Rudra, Alok; Amanti, Maria I; Scalari, Giacomo; Fischer, Milan; Giovannini, Marcella; Faist, Jerome; Kapon, Eli

304

Eight-band k·p modeling of InAs/InGaAsSb type-II W-design quantum well structures for interband cascade lasers emitting in a broad range of mid infrared  

SciTech Connect (OSTI)

Band structure properties of the type-II W-design AlSb/InAs/GaIn(As)Sb/InAs/AlSb quantum wells have been investigated theoretically in a systematic manner and with respect to their use in the active region of interband cascade laser for a broad range of emission in mid infrared between below 3 to beyond 10??m. Eight-band k·p approach has been utilized to calculate the electronic subbands. The fundamental optical transition energy and the corresponding oscillator strength have been determined in function of the thickness of InAs and GaIn(As)Sb layers and the composition of the latter. There have been considered active structures on two types of relevant substrates, GaSb and InAs, introducing slightly modified strain conditions. Additionally, the effect of external electric field has been taken into account to simulate the conditions occurring in the operational devices. The results show that introducing arsenic as fourth element into the valence band well of the type-II W-design system, and then altering its composition, can efficiently enhance the transition oscillator strength and allow additionally increasing the emission wavelength, which makes this solution prospective for improved performance and long wavelength interband cascade lasers.

Ryczko, K.; S?k, G.; Misiewicz, J. [Institute of Physics, Wroc?aw University of Technology, Wybrze?e Wyspia?skiego 27, 50-370 Wroc?aw (Poland)

2013-12-14T23:59:59.000Z

305

Optimized switching scheme of cascaded H-bridge multilevel inverter using PSO  

Science Journals Connector (OSTI)

Abstract The paper uses particle swarm optimization (PSO) to determine the optimum switching angles of cascaded H-bridge multilevel inverter (CH-MLI) so as to produce the required fundamental voltage and reduce the harmonic content. This is done by solving the transcendental equations characterizing the harmonic content. The validity of the proposed method is verified through simulation studies for three-phase, five-level CH-MLI. To compare the results obtained using PSO, the simulation studies have been extended for three-phase, five-level CH-MLI using sinusoidal pulse width modulation (SPWM). The results obtained using PSO are found superior as compared to SPWM in terms of total harmonic distortion at different modulation indices.

Vivek Kumar Gupta; R. Mahanty

2015-01-01T23:59:59.000Z

306

Application of multi-subband self-consistent energy balance method to terahertz quantum cascade lasers  

Science Journals Connector (OSTI)

We present simulation results for two resonant phonon terahertz quantum cascade lasers using a self-consistent energy balance model, which determines the electron temperature for each conduction subband. These temperatures, along with the electron populations and scattering rates, are determined in a manner similar to previously published models. However, the presented model is able to converge through the use of an algorithm that appears to be robust. The predicted individual subband electron temperatures, population densities and scattering rates are compared to previously published Monte Carlo and experimental studies for both lasers, where subband temperature variations were observed. These quantities were chosen since they provided the only comparison to modeling results from other studies.

Philip Slingerland; Christopher Baird; Robert H Giles

2012-01-01T23:59:59.000Z

307

Monitoring Alfvén Cascades with Interferometry on the JET Tokamak  

Science Journals Connector (OSTI)

A microwave interferometry technique is applied for the first time for detecting a discrete spectrum of Alfvén cascade (AC) eigenmodes excited with fast ions in reversed magnetic shear plasmas of the Joint European Torus. The interferometry measurements of plasma density perturbations associated with ACs show an unprecedented frequency and time resolution superior to that obtained with external magnetic coils. The measurements of ACs are used for monitoring the evolution of the safety factor and density of rational magnetic surfaces in the region of maximum plasma current.

S. E. Sharapov; B. Alper; J. Fessey; N. C. Hawkes; N. P. Young; R. Nazikian; G. J. Kramer; D. N. Borba; S. Hacquin; E. De La Luna; S. D. Pinches; J. Rapp; D. Testa; JET-EFDA Contributors

2004-10-12T23:59:59.000Z

308

Cascaded Cerenkov third-harmonic generation in random quadratic media  

SciTech Connect (OSTI)

We investigate experimentally and theoretically the conical emission of Cerenkov-type third-harmonic generation in strontium barium niobate of random 2D-{chi}{sup (2)} distribution. The azimuthal intensity distribution is explained by the polarization properties of the fundamental and Cerenkov second-harmonic waves, depending on the cascaded origin of the generation process. Moreover, we show the role of the individual domain shape in an additional modulation on the conical emission, controlled by the electrical switching of the spontaneous polarization of the ferroelectric medium.

Ayoub, Mousa; Roedig, Philip; Imbrock, Joerg; Denz, Cornelia [Institute of Applied Physics and Center for Nonlinear Science (CeNoS), Westfaelische Wilhelms-Universitaet Muenster, Corrensstrasse 2, 48149 Muenster (Germany)

2011-12-12T23:59:59.000Z

309

Entanglement amplification in a nondegenerate three-level cascade laser  

SciTech Connect (OSTI)

We analyze a nondegenerate three-level cascade laser coupled to a two-mode vacuum reservoir employing the stochastic differential equations associated with the normal ordering. We study the squeezing properties and entanglement amplification of the cavity radiation. We also calculate the correlation of the photon numbers and the fluctuations of the intensity difference. It turns out that the generated light exhibits a two-mode squeezing and entanglement when initially there are more atoms in the lower level. Moreover, a strong correlation between photon numbers along with a significant fluctuation in the intensity difference is found.

Tesfa, Sintayehu [Physics Department, Addis Ababa University, P. O. Box 1176, Addis Ababa (Ethiopia)

2006-10-15T23:59:59.000Z

310

Synthesis of a Leucomitosane via a Diastereoselective Radical Cascade  

Science Journals Connector (OSTI)

GC analyses were carried out on a GC instrument fitted with an Optima delta-3-0.25 ?m capillary column (20 m, 0.25 mm); gas carrier, He 1.4 mL/min; injector, 220 °C split mode; detector, FID 280 °C, H2 35 mL/min, air 350 mL/min. ... cascade of a 1,3,4-oxadiazole in which the pentacyclic skeleton and all the stereochem. of the natural products are assembled in a reaction that forms three rings, four C-C bonds, and five stereogenic centers including three contiguous quaternary centers, and introduces the correct oxidn. ...

François Brucelle; Philippe Renaud

2013-05-30T23:59:59.000Z

311

E-Print Network 3.0 - axial turbine cascade Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

High Solidity Vertical Axis Wind Turbine Andrzej J. Fiedler... ABSTRACT A high solidity, small scale, 2.5m diameter by 3m high Vertical Axis Wind Turbine (VAWT Source: Tullis,...

312

E-Print Network 3.0 - alfven wave cascade Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics ; Plasma Physics and Fusion 79 Hot Solar-Wind Helium: Direct Evidence for Local Heating by Alfven-Cyclotron Dissipation J. C. Kasper* Summary: to the Alfven wave speed...

313

E-Print Network 3.0 - annular sector cascade Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

nuclear industries where two-phase mixtures coexist. In the petroleum sector, gas... of inclination, and holdup were used as input. The output layer was consisted of slug,...

314

Deuteron form factors in chiral effective theory: regulator-independent results and the role of two-pion exchange  

E-Print Network [OSTI]

We evaluate the deuteron charge, quadrupole, and magnetic form factors using wave functions obtained from chiral effective theory ($\\chi$ET) when the potential includes one-pion exchange, chiral two-pion exchange, and genuine contact interactions. We study the manner in which the results for form factors behave as the regulator is removed from the $\\chi$ET calculation, and compare co-ordinate- and momentum-space approaches. We show that, for both the LO and NNLO chiral potential, results obtained by imposing boundary conditions in co-ordinate space at $r=0$ are equivalent to the $\\Lambda \\to \\infty$ limit of momentum-space calculations. The regulator-independent predictions for deuteron form factors that result from taking the $\\Lambda \\to \\infty$ limit using the LO $\\chi$ET potential are in reasonable agreement with data up to momentum transfers of order 600 MeV, provided that phenomenological information for nucleon structure is employed. In this range the use of the NNLO $\\chi$ET potential results in only small changes to the LO predictions, and it improves the description of the zero of the charge form factor.

M. Pavon Valderrama; A. Nogga; E. Ruiz Arriola; D. R. Phillips

2007-11-29T23:59:59.000Z

315

FY 2005 Quantum Cascade Laser Alignment System Final Report  

SciTech Connect (OSTI)

The Alignment Lasers Task of Pacific Northwest National Laboratory's (PNNL's) Remote Spectroscopy Project (Project PL211I) is a co-funded project between DOE NA-22 and a Classified Client. This project, which began in the second half of FY03, involved building and delivering a Quantum Cascade (QC) Laser Alignment System to be used for testing the pupil alignment of an infrared sensor by measuring the response from four pairs of diametrically opposed QC lasers. PNNL delivered the system in FY04 and provided technical assistance in FY05 culminating into a successful demonstration of the system. This project evolved from the Laser Development Task of PL211I, which is involved in developing novel laser technology to support development of advanced chemical sensors for detecting the proliferation of nuclear weapons. The laser systems are based on quantum cascade (QC) lasers, a new semiconductor source in the infrared. QC lasers can be tailored to emit light throughout the infrared region (3.5 ? 17 ?m) and have high output power and stability. Thus, these lasers provide an infrared source with superb power and spectral stability enabling them to be used for applications such as alignment and calibration in addition to chemical sensing.

Myers, Tanya L.; Cannon, Bret D.; Wojcik, Michael D.; Broocks, Bryan T.; Stewart, Timothy L.; Hatchell, Brian K.

2006-01-11T23:59:59.000Z

316

Superfluid Turbulence from Quantum Kelvin Wave to Classical Kolmogorov Cascades  

SciTech Connect (OSTI)

The main topological feature of a superfluid is a quantum vortex with an identifiable inner and outer radius. A novel unitary quantum lattice gas algorithm is used to simulate quantum turbulence of a Bose-Einstein condensate superfluid described by the Gross-Pitaevskii equation on grids up to 5760{sup 3}. For the first time, an accurate power-law scaling for the quantum Kelvin wave cascade is determined: k{sup -3}. The incompressible kinetic energy spectrum exhibits very distinct power-law spectra in 3 ranges of k space: a classical Kolmogorov k{sup -(5/3)} spectrum at scales greater than the outer radius of individual quantum vortex cores and a quantum Kelvin wave cascade spectrum k{sup -3} on scales smaller than the inner radius of the quantum vortex core. The k{sup -3} quantum Kelvin wave spectrum due to phonon radiation is robust, while the k{sup -(5/3)} classical Kolmogorov spectrum becomes robust on large grids.

Yepez, Jeffrey [Air Force Research Laboratory, Hanscom Air Force Base, Massachusetts 01731 (United States); Vahala, George [Department of Physics, William and Mary, Williamsburg, Virginia 23185 (United States); Vahala, Linda [Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States); Soe, Min [Department of Mathematics and Physical Sciences, Rogers State University, Claremore, Oklahoma 74017 (United States)

2009-08-21T23:59:59.000Z

317

Direct and Inverse Cascades in the Wind-Driven Sea  

E-Print Network [OSTI]

We offer a new form for the S(nl) term in the Hasselmann kinetic equation for squared wave amplitudes of wind-driven gravity wave. This form of S(nl) makes possible to rewrite in differential form the conservation laws for energy, momentum, and wave action, and introduce their fluxes by a natural way. We show that the stationary kinetic equation has a family of exact Kolmogorov-type solutions governed by the fluxes of motion constants: wave action, energy, and momentum. The simple "local" model for S(nl) term that is equivalent to the "diffusion approximation" is studied in details. In this case, Kolmogorov spectra are found in the explicit form. We show that a general solution of the stationary kinetic equation behind the spectral peak is described by the Kolmogorov-type solution with frequency-dependent fluxes. The domains of "inverse cascade" and "direct cascade" can be separated by natural way. The spectrum in the universal domain is close to $\\omega^{-4}$.

Zakharov, Vladimir E

2015-01-01T23:59:59.000Z

318

A loophole to the universal photon spectrum in electromagnetic cascades: application to the "cosmological lithium problem"  

E-Print Network [OSTI]

The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang nucleosynthesis (BBN). However, once the energy of the injected photons falls below the pair-production threshold the spectral shape is very different, a fact that has been overlooked in past literature. This loophole may have important phenomenological consequences, since it generically alters the BBN bounds on non-thermal relics: for instance it allows to re-open the possibility of purely electromagnetic solutions to the so-called "cosmological lithium problem", which were thought to be excluded by other cosmological constraints. We show this with a proof-of-principle example and a simple particle physics model, compared with previous literature.

Vivian Poulin; Pasquale D. Serpico

2015-02-04T23:59:59.000Z

319

A loophole to the universal photon spectrum in electromagnetic cascades: application to the "cosmological lithium problem"  

E-Print Network [OSTI]

The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang nucleosynthesis (BBN). However, once the energy of the injected photons falls below the pair-production threshold the spectral shape is very different, a fact that has been overlooked in past literature. This loophole may have important phenomenological consequences, since it generically alters the BBN bounds on non-thermal relics: for instance it allows to re-open the possibility of purely electromagnetic solutions to the so-called "cosmological lithium problem", which were thought to be excluded by other cosmological constraints. We show this with a proof-of-principle example and a simple particle physics model, compared with previous literature.

Poulin, Vivian

2015-01-01T23:59:59.000Z

320

Cascade utilization of chemical energy of natural gas in an improved CRGT cycle  

Science Journals Connector (OSTI)

In this paper three advanced power systems: the chemically recuperated gas turbine (CRGT) cycle, the steam injected gas turbine (STIG) cycle and the combined cycle (CC), are investigated and compared by means of exergy analysis. Making use of the energy level concept, cascaded use of the chemical exergy of natural gas in a CRGT cycle is clarified, and its performance of the utilization of chemical energy is evaluated. Based on this evaluation, a new CRGT cycle is designed to convert the exergy of natural gas more efficiently into electrical power. As a result, the exergy efficiency of the new CRGT cycle is about 55%, which is 8 percentage points higher than that of the reference CRGT cycle. The analysis gave a better interpretation of the inefficiencies of the CRGT cycle and suggested improvement options. This new approach can be used to design innovative energy systems.

Wei Han; Hongguang Jin; Na Zhang; Xiaosong Zhang

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Frequency and phaselock control of a 3 THz quantum cascade laser.  

SciTech Connect (OSTI)

We have locked the frequency of a 3 THz quantum cascade laser (QCL) to that of a far-infrared gas laser with a tunable microwave offset frequency. The locked QCL line shape is essentially Gaussian, with linewidths of 65 and 141 kHz at the -3 and -10 dB levels, respectively. The lock condition can be maintained indefinitely, without requiring temperature or bias current regulation of the QCL other than that provided by the lock error signal. The result demonstrates that a terahertz QCL can be frequency controlled with 1-part-in-108 accuracy, which is a factor of 100 better than that needed for a local oscillator in a heterodyne receiver for atmospheric and astronomic spectroscopy.

Williams, Benjamin S. (Massachusetts Institute of Technology, Cambridge, MA); Hu, Qing (Massachusetts Institute of Technology, Cambridge, MA); Reno, John Louis; Boreiko, R. T. (University of Colorado, Boulder, CO); Betz, A. L. (University of Colorado, Boulder, CO); Kumar, S. (Massachusetts Institute of Technology, Cambridge, MA)

2005-03-01T23:59:59.000Z

322

Adaptive Selective Harmonic Minimization Based on ANNs for Cascade Multilevel Inverters With Varying DC Sources  

SciTech Connect (OSTI)

A new approach for modulation of an 11-level cascade multilevel inverter using selective harmonic elimination is presented in this paper. The dc sources feeding the multilevel inverter are considered to be varying in time, and the switching angles are adapted to the dc source variation. This method uses genetic algorithms to obtain switching angles offline for different dc source values. Then, artificial neural networks are used to determine the switching angles that correspond to the real-time values of the dc sources for each phase. This implies that each one of the dc sources of this topology can have different values at any time, but the output fundamental voltage will stay constant and the harmonic content will still meet the specifications. The modulating switching angles are updated at each cycle of the output fundamental voltage. This paper gives details on the method in addition to simulation and experimental results.

Filho, Faete [ORNL; Maia, Helder Z [UFMS, Department of Electrical Engineering; Mateus, Tiago Henrique D [ORNL; Ozpineci, Burak [ORNL; Tolbert, Leon M [ORNL; Pinto, Joao Onofre P [ORNL

2013-01-01T23:59:59.000Z

323

Risk-aware Attacks and Catastrophic Cascading Failures in U.S. Power Grid  

E-Print Network [OSTI]

Risk-aware Attacks and Catastrophic Cascading Failures in U.S. Power Grid Wenkai Wang, Qiao Cai Department, Stevens Institute of Technology, Hoboken, NJ 07030 Abstract--The power grid network is a complex of power grid in terms of cascading failures caused by node failures. Specifically, we define three metrics

Sun, Yan Lindsay

324

A Five-Level Three-Phase Hybrid Cascade Multilevel Inverter Using a Single DC Source  

E-Print Network [OSTI]

A Five-Level Three-Phase Hybrid Cascade Multilevel Inverter Using a Single DC Source for a PM to construct a 3-phase 5-level cascade multilevel inverter to be used as a drive for a PM traction motor. The 5-level inverter consists of a standard 3-leg inverter (one leg for each phase) and an H-bridge in series

Tolbert, Leon M.

325

Hybrid Cascaded H-bridges Multilevel Motor Drive Control for Electric Vehicles  

E-Print Network [OSTI]

Hybrid Cascaded H-bridges Multilevel Motor Drive Control for Electric Vehicles Zhong Du1 , Leon M vehicle motor drive applications and hybrid electric vehicle motor drive applications. Keywords: hybrid cascaded H-bridge multilevel converter, DC voltage balance control, multilevel motor drive, electric

Tolbert, Leon M.

326

Mode tuning of quantum cascade lasers through optical processing of chalcogenide glass claddings  

E-Print Network [OSTI]

. The nature of gas-sensing applications requires single- mode operation and good tunability. One wayMode tuning of quantum cascade lasers through optical processing of chalcogenide glass claddings July 2006 In this letter, we demonstrate a method of tuning quantum cascade QC lasers by modifying

Arnold, Craig B.

327

Demonstration of air-guided quantum cascade lasers without top claddings  

E-Print Network [OSTI]

Demonstration of air-guided quantum cascade lasers without top claddings V. Moreau1, M. Bahriz1, R Abstract: We report on quantum cascade lasers employing waveguides based on a predominant air confinement mechanism in which the active region is located immediately at the device top surface. The lasers employ

Painter, Oskar

328

Design of Microsecond Level and High Current Pulse Driver Systems for Quantum Cascade Lasers  

Science Journals Connector (OSTI)

This paper presents a microsecond, high current pulse generator to drive quantum cascade lasesrs. The driver systems consist of pulse generator; power amplifier; fast switches and constant current supply circuits. The pulse width and pulse repetition ... Keywords: microsecond level, high current, pulesd driver systems, quantum cascade laser

Lei Li; Chen Chen; Hai Yu; Chengjun Dong; Yiding Wang

2010-06-01T23:59:59.000Z

329

Universal Laws of Cascade of Turbulent Fluctuations ZhenSu She  

E-Print Network [OSTI]

1 Universal Laws of Cascade of Turbulent Fluctuations Zhen­Su She Department of Mathematics interactions. As fluctuations cascade, both mechanical law and statistical law are important to determine that the fundamental mechanical conception of the nature was doubteful when such phenomena as the heat radiation

Soatto, Stefano

330

Transient dynamics and food–web complexity in the Lotka–Volterra cascade model  

Science Journals Connector (OSTI)

...research-article Transient dynamics and food-web complexity in the Lotka-Volterra cascade...behaviour near equilibrium of model food webs correlate with their short-term transient...Lotka-Volterra cascade model of food webs provide the first evidence to answer this...

2001-01-01T23:59:59.000Z

331

Cascadability and reshaping properties of a saturable absorber inserted inside a RZ transmission line for future  

E-Print Network [OSTI]

absorber component cascaded into a 100-km SMF RZ transmission line in order to annihilate the ghost paid to transmission lines working at higher bit-rates, such as 160 Gbit/s [1]. However, many studies Absorber device cascaded inside a 100-km Single Mode Fiber (SMF)- based RZ transmission line cadenced

Paris-Sud XI, Université de

332

Number and propagation of line outages in cascading events in electric power transmission systems  

E-Print Network [OSTI]

Number and propagation of line outages in cascading events in electric power transmission systems of transmission lines. We estimate from observed utility data how transmission line outages propagate, and obtain of transmission lines. The multiple mechanisms involved these cascading outages are many and varied, and the power

Dobson, Ian

333

A quantum cascade laser in a transverse magnetic field. A model of the open triple-barrier active region  

Science Journals Connector (OSTI)

A theory of spectral parameters and active dynamic conductivity of the quantum cascade laser is proposed in the model of a triple-barrier active region of an individual cascade in a transverse magnetic field. In ...

N. V. Tkach; I. V. Boyko; Ju. A. Seti; G. G. Zegrya

2013-06-01T23:59:59.000Z

334

Inductorless DC-AC Cascaded H-bridge Multilevel Boost Inverter for Electric/Hybrid Electric Vehicle  

E-Print Network [OSTI]

Inductorless DC-AC Cascaded H-bridge Multilevel Boost Inverter for Electric/Hybrid Electric Vehicle University Boise, ID 83725, USA Abstract-This paper presents an inductorless cascaded H- bridge multilevel a bulky inductor. An inductorless cascaded H-bridge multilevel boost inverter for EV and HEV applications

Tolbert, Leon M.

335

Cascade Natural Gas - Conservation Incentives for Existing Homes |  

Broader source: Energy.gov (indexed) [DOE]

Existing Homes Existing Homes Cascade Natural Gas - Conservation Incentives for Existing Homes < Back Eligibility Residential Savings Category Home Weatherization Commercial Weatherization Sealing Your Home Ventilation Heating & Cooling Commercial Heating & Cooling Heating Appliances & Electronics Water Heating Program Info State District of Columbia Program Type Utility Rebate Program Rebate Amount Floor Insulation: $0.45 per sq. ft. Wall Insulation: $0.40 per sq. ft. Ceiling or Attic Insulation: $0.25 per sq. ft. High Efficiency Natural Gas Furnace: $150 Duct Sealing: $150 High Efficiency Natural Gas Furnace and Duct Sealing: $400 High Efficiency Natural Gas Hearth: $70 Conventional Natural Gas Water Heater: $40 Combination Domestic Water/Hydronic Space Heating System (using Tankless

336

Advanced quantum cascade laser transmitter architectures and infrared photonics development  

SciTech Connect (OSTI)

Quantum cascade lasers (QCLs) provide a viable infrared laser source for a new class of laser transmitters capable of meeting the performance requirements for a variety of national security and civilian applications. The high output power, small size, and superb stability and modulation characteristics of QCLs make them amenable for integration as transmitters into ultra-sensitive, ultra-selective point sampling and remote short-range chemical sensors. This paper reports on the current development in infrared photonics that provides a pathway for QCL transmitter miniaturization. This research has produced infrared waveguide-based optical components in chalcogenide glass using both direct-laser writing and holographic exposure techniques. We discuss here the design and fabrication concepts and capabilities required to produce integrated waveguides, waveguide couplers, and other photonic devices.

Anheier, Norman C.; Allen, Paul J.; Myers, Tanya L.

2004-08-01T23:59:59.000Z

337

Cascaded injection resonator for coherent beam combining of laser arrays  

DOE Patents [OSTI]

The invention provides a cascaded injection resonator for coherent beam combining of laser arrays. The resonator comprises a plurality of laser emitters arranged along at least one plane and a beam sampler for reflecting at least a portion of each laser beam that impinges on the beam sampler, the portion of each laser beam from one of the laser emitters being reflected back to another one of the laser emitters to cause a beam to be generated from the other one of the laser emitters to the beam reflector. The beam sampler also transmits a portion of each laser beam to produce a laser output beam such that a plurality of laser output beams of the same frequency are produced. An injection laser beam is directed to a first laser emitter to begin a process of generating and reflecting a laser beam from one laser emitter to another laser emitter in the plurality. A method of practicing the invention is also disclosed.

Kireev, Vassili [Sunnyvale, CA; Liu, Yun; Protopopescu, Vladimir [Knoxville, TN; Braiman, Yehuda [Oak Ridge, TN

2008-10-21T23:59:59.000Z

338

City of Cascade Locks, Oregon (Utility Company) | Open Energy Information  

Open Energy Info (EERE)

Oregon (Utility Company) Oregon (Utility Company) Jump to: navigation, search Name City of Cascade Locks Place Oregon Utility Id 3136 Utility Location Yes Ownership M NERC Location WECC NERC WECC Yes Activity Distribution Yes References EIA Form EIA-861 Final Data File for 2010 - File1_a[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Utility Rate Schedules Grid-background.png General Service- City Commercial General Service- City(Primary Metering) Commercial General Service- Rural Commercial General Service- Rural(Primary Metering) Commercial Public Agency Rate- City Commercial Public Agency Rate- City(Primary Metering) Commercial Public Agency Rate- Rural Commercial Public Agency Rate- Rural(Primary Metering) Commercial

339

Information cascade, Kirman’s ant colony model, and kinetic Ising model  

Science Journals Connector (OSTI)

Abstract In this paper, we discuss a voting model in which voters can obtain information from a finite number of previous voters. There exist three groups of voters: (i) digital herders and independent voters, (ii) analog herders and independent voters, and (iii) tanh -type herders. In our previous paper Hisakado and Mori (2011), we used the mean field approximation for case (i). In that study, if the reference number r is above three, phase transition occurs and the solution converges to one of the equilibria. However, the conclusion is different from mean field approximation. In this paper, we show that the solution oscillates between the two states. A good (bad) equilibrium is where a majority of r select the correct (wrong) candidate. In this paper, we show that there is no phase transition when r is finite. If the annealing schedule is adequately slow from finite r to infinite r , the voting rate converges only to the good equilibrium. In case (ii), the state of reference votes is equivalent to that of Kirman’s ant colony model, and it follows beta binomial distribution. In case (iii), we show that the model is equivalent to the finite-size kinetic Ising model. If the voters are rational, a simple herding experiment of information cascade is conducted. Information cascade results from the quenching of the kinetic Ising model. As case (i) is the limit of case (iii) when tanh function becomes a step function, the phase transition can be observed in infinite size limit. We can confirm that there is no phase transition when the reference number r is finite.

Masato Hisakado; Shintaro Mori

2015-01-01T23:59:59.000Z

340

Astrophysical gyrokinetics: kinetic and fluid turbulent cascades in magnetized weakly collisional plasmas  

E-Print Network [OSTI]

We present a theoretical framework for plasma turbulence in astrophysical plasmas (solar wind, interstellar medium, galaxy clusters, accretion disks). The key assumptions are that the turbulence is anisotropic with respect to the mean magnetic field and frequencies are low compared to the ion cyclotron frequency. The energy injected at the outer scale scale has to be converted into heat, which ultimately cannot be done without collisions. A KINETIC CASCADE develops that brings the energy to collisional scales both in space and velocity. Its nature depends on the physics of plasma fluctuations. In each of the physically distinct scale ranges, the kinetic problem is systematically reduced to a more tractable set of equations. In the "inertial range" above the ion gyroscale, the kinetic cascade splits into a cascade of Alfvenic fluctuations, which are governed by the RMHD equations at both the collisional and collisionless scales, and a passive cascade of compressive fluctuations, which obey a linear kinetic equation along the moving field lines associated with the Alfvenic component. In the "dissipation range" between the ion and electron gyroscales, there are again two cascades: the kinetic-Alfven-wave (KAW) cascade governed by two fluid-like Electron RMHD equations and a passive phase-space cascade of ion entropy fluctuations. The latter cascade brings the energy of the inertial-range fluctuations that was damped by collisionless wave-particle interaction at the ion gyroscale to collisional scales in the phase space and leads to ion heating. The KAW energy is similarly damped at the electron gyroscale and converted into electron heat. Kolmogorov-style scaling relations are derived for these cascades. Astrophysical and space-physical applications are discussed in detail.

A. A. Schekochihin; S. C. Cowley; W. Dorland; G. W. Hammett; G. G. Howes; E. Quataert; T. Tatsuno

2007-03-31T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Finite-size scaling of two-point statistics and the turbulent energy cascade generators  

Science Journals Connector (OSTI)

Within the framework of random multiplicative energy cascade models of fully developed turbulence, finite-size-scaling expressions for two-point correlators and cumulants are derived, taking into account the observationally unavoidable conversion from an ultrametric to an Euclidean two-point distance. The comparison with two-point statistics of the surrogate energy dissipation, extracted from various wind tunnel and atmospheric boundary layer records, allows an accurate deduction of multiscaling exponents and cumulants, even at moderate Reynolds numbers for which simple power-law fits are not feasible. The extracted exponents serve as input for parametric estimates of the probabilistic cascade generator. Various cascade generators are evaluated.

Jochen Cleve; Thomas Dziekan; Jürgen Schmiegel; Ole E. Barndorff-Nielsen; Bruce R. Pearson; Katepalli R. Sreenivasan; Martin Greiner

2005-02-28T23:59:59.000Z

342

Relay coordination and protection failure effects on reliability indices in an interconnected sub-transmission system  

Science Journals Connector (OSTI)

Protection system failure is the main cause of cascading outages. It has been shown that the hidden failures lead to cascading outages. However, the effects of the coordination method as well as the hidden failure of the protection systems have not been investigated yet. In this paper, an algorithm based on sequential Monte Carlo simulation is proposed to find the reliability indices for different overcurrent relay coordination methods. The proposed algorithm is applied to the results of different relay coordination methods of a real network. The indices SAIFI, CAIDI, CAIFI and ENS for the results of different relay coordination methods are obtained strictly based on the contribution of the protection failure issues. Then, a comparison is made between the results of the different relay coordination methods in order to show how the coordination methods affect the reliability indices.

Kazem Mazlumi; Hossein Askarian Abyaneh

2009-01-01T23:59:59.000Z

343

Health effects models for nuclear power plant accident consequence analysis. Modification of models resulting from addition of effects of exposure to alpha-emitting radionuclides: Revision 1, Part 2, Scientific bases for health effects models, Addendum 2  

SciTech Connect (OSTI)

The Nuclear Regulatory Commission (NRC) has sponsored several studies to identify and quantify, through the use of models, the potential health effects of accidental releases of radionuclides from nuclear power plants. The Reactor Safety Study provided the basis for most of the earlier estimates related to these health effects. Subsequent efforts by NRC-supported groups resulted in improved health effects models that were published in the report entitled {open_quotes}Health Effects Models for Nuclear Power Plant Consequence Analysis{close_quotes}, NUREG/CR-4214, 1985 and revised further in the 1989 report NUREG/CR-4214, Rev. 1, Part 2. The health effects models presented in the 1989 NUREG/CR-4214 report were developed for exposure to low-linear energy transfer (LET) (beta and gamma) radiation based on the best scientific information available at that time. Since the 1989 report was published, two addenda to that report have been prepared to (1) incorporate other scientific information related to low-LET health effects models and (2) extend the models to consider the possible health consequences of the addition of alpha-emitting radionuclides to the exposure source term. The first addendum report, entitled {open_quotes}Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, Modifications of Models Resulting from Recent Reports on Health Effects of Ionizing Radiation, Low LET Radiation, Part 2: Scientific Bases for Health Effects Models,{close_quotes} was published in 1991 as NUREG/CR-4214, Rev. 1, Part 2, Addendum 1. This second addendum addresses the possibility that some fraction of the accident source term from an operating nuclear power plant comprises alpha-emitting radionuclides. Consideration of chronic high-LET exposure from alpha radiation as well as acute and chronic exposure to low-LET beta and gamma radiations is a reasonable extension of the health effects model.

Abrahamson, S. [Wisconsin Univ., Madison, WI (United States); Bender, M.A. [Brookhaven National Lab., Upton, NY (United States); Boecker, B.B.; Scott, B.R. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.; Gilbert, E.S. [Pacific Northwest Lab., Richland, WA (United States)

1993-05-01T23:59:59.000Z

344

Role of linewidth enhancement factor on the frequency response of the synchronized quantum cascade laser  

Science Journals Connector (OSTI)

Abstract This paper presents a closed-form analysis of the synchronized quantum cascade laser (QCL) and studies analytically the effect of linewidth enhancement factor (LEF) on the frequency response of the QCL. The analysis predicts that there can be two types of response curves of the QCL—one like series resonant circuit response and the other like antiresonant circuit response. The linewidth enhancement factor introduces asymmetry in the frequency response of the synchronized QCL. The nature of asymmetry in locked QCL is seen to be different from that reported for interband semiconductor lasers. The asymmetry in series resonant-like response is inclined towards the positive detuning side while that in antiresonant circuit-like response is inclined towards the negative detuning side. The degree of asymmetry in QCL response is not only determined by the LEF but also by the upper subband electron relaxation time and the operating wavelength of the QCL. Although the value of LEF in QCL is smaller than that for interband lasers, calculation shows that the LEF has a profound effect on the response of the locked QCL.

Taraprasad Chattopadhyay; Prosenjit Bhattacharyya

2013-01-01T23:59:59.000Z

345

Cascade atom in high-Q cavity: The spectrum for non-Markovian decay  

E-Print Network [OSTI]

The spontaneous emission spectrum for a three level cascade configuration atom in a single mode high-Q cavity coupled to a zero temperature reservoir of continuum external modes is determined from the atom-cavity mode master equation using the quantum regression theorem. Initially the atom is in its upper state and the cavity mode empty of photons. Following Glauber, the spectrum is defined via the response of a detector atom. Spectra are calculated for the detector located inside the cavity (case A), outside the cavity end mirror (Case B-end emission), or placed for emission out the side of the cavity (Case C). The spectra for case A and case B are found to be essentially the same. In all the cases the predicted lineshapes are free of instrumental effects and only due to cavity decay. Spectra are presented for intermediate and strong coupling regime situations (where both atomic transitions are resonant with the cavity frequency), for cases of non-zero cavity detuning, and for cases where the two atomic transition frequencies differ. The spectral features for Cases B(A) and C are qualitatively similar, with six spectral peaks for resonance cases and eight for detuned cases. These general features of the spectra can be understood via the dressed atom model. However, Case B and C spectra differ in detail, with the latter exhibiting a deep spectral hole at the cavity frequency due to quantum interference effects.

B. J. Dalton; B. M. Garraway

2007-07-08T23:59:59.000Z

346

Isotopic Analysis At Cascades Region (Kennedy & Van Soest, 2007) | Open  

Open Energy Info (EERE)

Analysis At Cascades Region (Kennedy & Van Soest, 2007) Analysis At Cascades Region (Kennedy & Van Soest, 2007) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-Fluid At Cascades Region (Kennedy & Van Soest, 2007) Exploration Activity Details Location Cascades Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced permeability and that mantle fluids can penetrate the ductile lithosphere, even in regions where there is no substantial magmatism. Superimposed on the regional trend are local, high 3He/4He anomalies indicating hidden magmatic activity and/or deep

347

Energy spectrum of cascade showers generated in water by near-horizontal muons  

Science Journals Connector (OSTI)

We discuss measuring cascade shower energy using the NEVOD Cherenkov water detector with ... applied to showers generated by near-horizontal high-energy muons selected using the DECOR coordinate detector deployed...

S. S. Khokhlov; N. S. Barbashina…

2013-05-01T23:59:59.000Z

348

Summary of activities in the Working Group on QCD Cascades of the HERA Monte Carlo workshop  

E-Print Network [OSTI]

We summarize the activities in working group 10 concerned with QCD cascades, and find that although much work still needs to be done, much progress was made during this workshop in understanding the merits and deficiencies of different programs.

Nick Brook; Leif Lonnblad

1999-08-16T23:59:59.000Z

349

Summary of activities in the Working Group on QCD Cascades of the HERA Monte Carlo workshop  

E-Print Network [OSTI]

We summarize the activities in working group 10 concerned with QCD cascades, and find that although much work still needs to be done, much progress was made during this workshop in understanding the merits and deficiencies of different programs.

Brook, N; Brook, Nick; Lonnblad, Leif

1999-01-01T23:59:59.000Z

350

Advanced fault diagnosis techniques and their role in preventing cascading blackouts  

E-Print Network [OSTI]

This dissertation studied new transmission line fault diagnosis approaches using new technologies and proposed a scheme to apply those techniques in preventing and mitigating cascading blackouts. The new fault diagnosis approaches are based on two...

Zhang, Nan

2007-04-25T23:59:59.000Z

351

Finite-State Transducer Cascade to Extract Proper Names in Texts  

Science Journals Connector (OSTI)

This article describes a finite-state cascade for the extraction of person names in texts in French. We extract these proper names in order to categorize and to cluster texts with them. After a finite-state pr...

Nathalie Friburger; 1]Denis Maurel

2002-01-01T23:59:59.000Z

352

Good Cascade Impactor Practice (GCIP) and Considerations for “In-Use” Specifications  

Science Journals Connector (OSTI)

The multi-stage cascade impactor (CI) is widely used to determine aerodynamic particle size distributions (APSDs) of orally inhaled products. Its size-fractionating capability depends primarily on the size of ...

S. C. Nichols; J. P. Mitchell; C. M. Shelton; D. L. Roberts

2013-03-01T23:59:59.000Z

353

A cascaded photonic crystal fiber Mach–Zehnder interferometer formed by extra electric arc discharges  

Science Journals Connector (OSTI)

In this paper, a cascaded Mach–Zehnder interferometer based on a photonic crystal fiber is reported. It is demonstrated that by applying a small dose of extra arc discharge to the photonic crystal fiber sensin...

Y. Geng; X. Li; X. Tan; Y. Deng; Y. Yu

2011-03-01T23:59:59.000Z

354

Observation of cascaded two-photon-induced transitions between fluxoid states of a SQUID  

E-Print Network [OSTI]

We present evidence for transitions between fluxoid wells of a SQUID due to cascaded, two-photon processes. Such transitions are evidenced by an anomalous dependence on the transition rate from the one-photon resonant level ...

Han, Siyuan; Lukens, J. E.; Rouse, R.

2000-02-07T23:59:59.000Z

355

Quantum-cascade laser photoacoustic detection of methane emitted from natural gas powered engines  

Science Journals Connector (OSTI)

In this work we present a laser photoacoustic arrangement for the detection of the important greenhouse gas methane. A quantum-cascade laser and a differential photoacoustic cell were ... tested in the detection ...

M. V. Rocha; M. S. Sthel; M. G. Silva; L. B. Paiva; F. W. Pinheiro…

2012-03-01T23:59:59.000Z

356

Mixed Refrigerant Cascade Liquefiers for Natural Gas—Design and Optimization  

Science Journals Connector (OSTI)

This paper describes the development of highly flexible calculation methods and computer programs to deal with the complex problems encountered in the design of Mixed Refrigerant Cascade (MRC) plants. The relativ...

D. T. Linnett; K. C. Smith

1995-01-01T23:59:59.000Z

357

The damped natural oscillations of a gas flowing past a cascade of flat plates  

Science Journals Connector (OSTI)

We solve the problem of the natural oscillations of a gas flowing past a cascade of flat plates under the Joukowsky-Chaplygin ... case part of the energy of the oscillating gas is consumed in the formation of a ....

V. B. Kurzin

358

Label Free Mid-IR Photothermal Imaging of Bird Brain With Quantum Cascade Laser  

Science Journals Connector (OSTI)

Label free mid-infrared photothermal imaging on bird brain slices is presented. The Amide-I vibrational band is excited by a quantum cascade laser and an Er:doped fiber measures the...

Mertiri, Alket; Totachawattana, Atcha; Liu, Hui; Hong, Mi K; Gardner, Tim; Sander, Michelle Y; Erramilli, Shyamsunder

359

Active hyperspectral imaging using a quantum cascade laser (QCL) array and digital-pixel focal  

E-Print Network [OSTI]

, D. L. Sivco, and A. Y. Cho, "Quantum cascade lasers," Phys. Today 55(5), 34 (2002). 13. Daylight Solutions, Inc., www.daylightsolutions.com; Block Engineering LLC, www.blockeng.com. 14. B. G. Lee, M. A

Capasso, Federico

360

Optimization of an External Cavity Quantum Cascade Laser for Chemical Sensing Applications  

SciTech Connect (OSTI)

We describe and characterize an external cavity quantum cascade laser designed for detection of multiple airborne chemicals, and used with a compact astigmatic Herriott cell for sensing of acetone and hydrogen peroxide.

Phillips, Mark C.; Bernacki, Bruce E.; Taubman, Matthew S.; Cannon, Bret D.; Schiffern, John T.; Myers, Tanya L.

2010-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Design of Laser Transition Oscillator Strength for THz Quantum Cascade Lasers  

Science Journals Connector (OSTI)

The density matrix based model is employed to design number of THz quantum cascade lasers with various laser oscillator strengths. The optimum oscillator strength varies between 0.35...

Fathololoumi, Saeed; Dupont, Emmanuel; Laframboise, Sylvain R; Wasilewski, Zbigniew R; Ban, Dayan; Liu, Hc

362

Pulsed High Duty-Cycle Operation of ? ~ 8µm Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We report on high duty-cycle pulsed and burst-mode operation of ?~8µm quantum cascade lasers under ambient conditions for photo-acoustic spectroscopy. An optimum in average optical...

Ko, Tiffany; Liu, Zhijun; Gmachl, Claire

363

Spectroscopic detection of hazardous substances using broadband-tunable Quantum Cascade Lasers  

Science Journals Connector (OSTI)

External-Cavity-Quantum Cascade Lasers are attractive sources for mid-infrared spectroscopy. We demonstrate the possibilities offered by EC-QCLs by two examples: Standoff detection of...

Hugger, Stefan; Fuchs, Frank; Jarvis, Jan; Yang, Quankui; Driad, Rachid; Bronner, Wolfgang; Aidam, Rolf; Ostendorf, Ralf; Wagner, Joachim

364

Electron microscopy of GaAs/AlGaAs quantum cascade laser  

Science Journals Connector (OSTI)

The quantum cascade laser (QCL) is based on a different principle comparing to bipolar semiconductor lasers, because it uses only one type of ... — electrons and therefore is called an unipolar laser.

A. ?aszcz; J. Ratajczak; A. Czerwinski…

2008-01-01T23:59:59.000Z

365

Near-Infrared Laser Pulse Induced Amplitude Modulation of Terahertz Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We have demonstrated amplitude modulation of terahertz quantum cascade lasers by means of the injection of near-infrared laser pulses. Injected 770nm and 1350nm laser pulses both...

Sakasegawa, Yohei; Saito, Shingo; Sekine, Norihiko; Ashida, Masaaki; Hosako, Iwao

366

Superconducting Microbolometer with Microsecond Time Constant Coupled to Quantum Cascade Lasers  

Science Journals Connector (OSTI)

A superconducting bolometer with an on-chip lithographic terahertz antenna has been illuminated by two quantum cascade lasers operating at 2.5 and 4.4 THz to be used for wide dynamic...

Cibella, Sara; Ortolani, Michele; Leoni, Roberto; Torrioli, Guido; Tredicucci, Alessandro; Mahler, L; Xu, Ji-Hua; Beere, H E; Ritchie, D A

367

Gain to Absorption Ratio of Self-Induced Transparency Modelocked Quantum Cascade Lasers  

Science Journals Connector (OSTI)

A model to calculate the gain to absorption ratio of self-induced transparency modelocked quantum cascade lasers is presented and then used to find the gain to absorbing periods ratio...

Talukder, Muhammad; Menyuk, Curtis

368

Broadly tunable quantum cascade laser in cantilever-enhanced photoacoustic infrared spectroscopy of solids  

Science Journals Connector (OSTI)

An external cavity quantum cascade laser (EC-QCL) is applied in the...?1 (970–1,646 cm?1) in the mid-infrared region, which enables accurate broadband spectroscopy of large molecules. The high spectral power den...

J. Lehtinen; T. Kuusela

2014-06-01T23:59:59.000Z

369

Development of a compact quantum cascade laser spectrometer for field measurements of CO2 isotopes  

Science Journals Connector (OSTI)

We report the development of a field-deployable, pulsed quantum cascade laser spectrometer. The instrument is designed to measure...13C/12C isotopic ratio in the CO2 released from volcanic vents. Specific 12CO2 a...

D. Weidmann; G. Wysocki; C. Oppenheimer; F.K. Tittel

2005-02-01T23:59:59.000Z

370

Intra-pulse beam steering in a mid-infrared quantum cascade laser  

Science Journals Connector (OSTI)

The intra-pulse measurements of the beam steering in an AlGaAs/GaAs quantum cascade laser are presented in this paper. The experimental ... theoretical model. The near field of the laser radiation is calculated a...

Emilia Pruszy?ska-Karbownik; Kazimierz Regi?ski…

2014-08-01T23:59:59.000Z

371

Lateral Current Density Distribution and Spatial Hole Burning in Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We have investigated non-uniformity of the lateral current density and lateral hole burning in Quantum Cascaded lasers, e.g., the current density in the mode center is 1.8 times that...

Huang, Xue; Dikmelik, Yamac; Gmachl, Claire F

372

Hyperspectral microscopy using an external cavity quantum cascade laser and its applications for explosives detection  

SciTech Connect (OSTI)

A hyperspectral infrared microscope using external cavity quantum cascade laser illumination and a microbolometer focal plane array is used to characterize nanogram-scale particles of the explosives RDX, tetryl, and PETN at fast acquisition rates.

Phillips, Mark C.; Suter, Jonathan D.; Bernacki, Bruce E.

2012-04-01T23:59:59.000Z

373

Direct Modulation of Quantum Cascade Lasers for Chirped Laser Dispersion Spectroscopy  

Science Journals Connector (OSTI)

This paper provides an analysis of direct modulation of a quantum cascade laser for applications in chirped laser dispersion spectroscopy (CLaDS). The developed laser model is used to...

Hangauer, Andreas; Spinner, Georg; Nikodem, Michal; Wysocki, Gerard

374

Sensitive detection of acrolein and acrylonitrile with a pulsed quantum-cascade laser  

Science Journals Connector (OSTI)

We report on spectroscopic measurements of acrolein and acrylonitrile at atmospheric pressure using a pulsed distributed feedback quantum-cascade laser in combination with intra- and inter-pulse...?1. In the inte...

J. Manne; A. Lim; J. Tulip; W. Jäger

2012-05-01T23:59:59.000Z

375

A multi-tiered memetic multiobjective evolutionary algorithm for the design of quantum cascade lasers  

Science Journals Connector (OSTI)

Recent advances in quantum cascade lasers (QCLs) have enabled their use as (tunable) emission sources for chemical and biological spectroscopy, as well as allowed their demonstration in applications in medical diagnostics and potential homeland security ...

Mark P. Kleeman; Gary B. Lamont; Adam Cooney; Thomas R. Nelson

2007-03-01T23:59:59.000Z

376

Sub-ppb detection of formaldehyde with cantilever enhanced photoacoustic spectroscopy using quantum cascade laser source  

Science Journals Connector (OSTI)

A novel cantilever enhanced photoacoustic spectrometer with mid-infrared quantum cascade laser was applied for selective and sensitive formaldehyde...2O) gas measurement. The spectrum of formaldehyde was measured...

C. B. Hirschmann; J. Lehtinen; J. Uotila; S. Ojala; R. L. Keiski

2013-06-01T23:59:59.000Z

377

Quantum cascade laser-based carbon monoxide detection on a second time scale from human breath  

Science Journals Connector (OSTI)

We present three different detection schemes for measuring carbon monoxide (CO) in direct absorption using a thermoelectrically cooled, distributed-feedback pulsed quantum cascade (qc) laser operating between 217...

B.W.M. Moeskops; H. Naus; S.M. Cristescu; F.J.M. Harren

2006-03-01T23:59:59.000Z

378

Synthesis of Marine Polycyclic Polyethers via Endo-Selective Epoxide-Opening Cascades  

E-Print Network [OSTI]

The proposed biosynthetic pathways to ladder polyethers of polyketide origin and oxasqualenoids of terpenoid origin share a dramatic epoxide-opening cascade as a key step. Polycyclic structures generated in these biosynthetic ...

Vilotijevic, Ivan

379

Surface-emitting distributed feedback terahertz quantum-cascade phase-locked laser arrays  

E-Print Network [OSTI]

A new approach to achieve high-power, symmetric beam-pattern, single-mode THz emission from metal-metal waveguide quantum-cascade laser is proposed and implemented. Several surface-emitting distributed feedback terahertz ...

Kao, Tsung-Yu

2009-01-01T23:59:59.000Z

380

High-Power Thermoelectrically-Cooled and Uncooled Mid-Wave Infrared Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We present high performance thermoelectrically-cooled and uncooled mid-wave infrared (?=4.6 ?m) quantum cascade lasers with continuous-wave output power of 2.9 W and 1 W at room...

Maulini, Richard; Lyakh, Arkadiy; Tsekoun, Alexei; Pflugl, Christian; Diehl, Laurent; Capasso, Federico; Patel, Kumar

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Quantum mechanical model of the upper bounds of the cascading contribution to the second hyperpolarizability  

SciTech Connect (OSTI)

Microscopic cascading of second-order nonlinearities between two molecules has been proposed to yield an enhanced third-order molecular nonlinear-optical response. In this contribution, we investigate the two-molecule cascaded second hyperpolarizability and show that it will never exceed the fundamental limit of a single molecule with the same number of electrons as the two-molecule system. We show the apparent divergence behavior of the cascading contribution to the second hyperpolarizability vanishes when properly taking into account the intermolecular interactions. Although cascading can never lead to a larger nonlinear-optical response than a single molecule, it provides alternative molecular design configurations for creating materials with large third-order susceptibilities that may be difficult to design into a single molecule.

Dawson, Nathan J.; Anderson, Benjamin R.; Schei, Jennifer L.; Kuzyk, Mark G. [Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States)

2011-10-15T23:59:59.000Z

382

Heat Flow From Four New Research Drill Holes In The Western Cascades...  

Open Energy Info (EERE)

Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Heat Flow From Four New...

383

A Cascade-Type Global Energy Conversion Diagram Based on Wave–Mean Flow Interactions  

Science Journals Connector (OSTI)

A cascade-type energy conversion diagram is proposed for the purpose of diagnosing the atmospheric general circulation based on wave–mean flow interactions. Mass-weighted isentropic zonal means facilitate the expression of nongeostrophic wave ...

Sachiyo Uno; Toshiki Iwasaki

2006-12-01T23:59:59.000Z

384

Drought effects on litterfall, wood production and belowground carbon cycling in an Amazon forest: results of a throughfall reduction experiment  

Science Journals Connector (OSTI)

...properly cited. Drought effects on litterfall, wood production and belowground carbon cycling in an...Barbosa, 136, 68005-080 Santarem, Para, Brazil 2 Woods Hole Research Center149 Woods Hole Road, Falmouth, MA 02543, USA 3 Department...

2008-01-01T23:59:59.000Z

385

GaInAs/AlInAs quantum cascade laser design based on optimized second harmonic generation  

Science Journals Connector (OSTI)

In this work, we present an innovative procedure for the design and optimization of GaInAs/AlInAs quantum cascade laser (QCL) structures based on the use of the genetic algorithm. The purpose of the algorithm is to determine the set of design parameters that would enable the maximization of the second order nonlinear susceptibility, thus facilitating significant optical nonlinearities to take place. In our optimization model, we start from the existing design in which the active region consists of two coupled InGaAs quantum wells separated by an AlInAs barrier, and the active region levels form double resonant nonlinear cascades. Upon obtaining the optimized structure and evaluating its energies and wave functions, the output characteristics are calculated by applying the full self-consistent rate equation modeling of the electron transport in a periodic QCL structure. The results of the calculations predict a noticeable improvement of targeted properties of the optimized design, while at the same time the original design calculations show excellent agreement with experimental results. The described procedure is applicable to various active region designs and can be used for other wavelength ranges.

A Gaji?; J Radovanovi?; V Milanovi?; D Indjin; Z Ikoni?

2014-01-01T23:59:59.000Z

386

Molecular-beam epitaxy growth and characterization of mid-infrared quantum cascade laser structures  

Science Journals Connector (OSTI)

The development of molecular-beam epitaxy (MBE) of GaAs/AlGaAs heterostructures, used for fabrication of ~9?m quantum cascade lasers (QCLs), is reported. The X-ray diffractometry (XRD) structural characterization, as an integral part of this process, ... Keywords: GaAs/AlGaAs lasers, Intersubband transitions, Mid-infrared, Molecular-beam epitaxy, Quantum cascade laser, Unipolar devices

Kamil Kosiel; Justyna Kubacka-Traczyk; Piotr Karbownik; Anna Szerling; Jan Muszalski; Maciej Bugajski; Przemek Romanowski; Jaros?aw Gaca; Marek Wójcik

2009-03-01T23:59:59.000Z

387

Gamma-ray cascade transitions from resonant neutron capture in Cd-111 and Cd-113  

SciTech Connect (OSTI)

A neutron-capture experiment on {sup nat}Cd has been carried out at DANCE. Multiple-fold coincidence {gamma}-ray spectra have been collected from J=0, 1 resonances in {sup 111}Cd and {sup 113}Cd. The cascades ending at the ground state can be described by the SLO model while the cascades ending at the 2+ states are better reproduced by the mixed SLO+KMF model.

Rusev, Gencho Y. [Los Alamos National Laboratory

2012-08-27T23:59:59.000Z

388

Cascaded multilevel converter based superconducting magnetic energy storage system for frequency control  

Science Journals Connector (OSTI)

Abstract The Super conducting magnetic energy storage (SMES), owing to high energy density and capacity, has been widely applied in different stages of power systems. One of these applications is the frequency control of the electric power systems. Frequency of a power system depends on the balance of produced and demanded energy in any instant of time. Subsequent to a sudden change in the system, which causes produced and demanded energy mismatch, frequency oscillates. According to standards, the permissible variation band of the frequency is very restricted. Larger swings of frequency may result in instability and undesirable trips. As a result, suitable frequency control mechanisms should be implemented in the system. SMES is well-suited for this application because of high energy density and fast response. SMES is attached to system by a power conditioning system (PCS) which include power electronic converters, mainly a dc–dc chopper and an inverter. This paper, studies the application of a cascaded H-bridge (CHB) multilevel converter for frequency control. As far as the authors' knowledge, such a study has not been done before. The design procedure of the converter is presented. Simulation results on a sample system are presented to verify the performance of the proposed PCS.

Mohammad Farhadi Kangarlu; Mohammad Reza Alizadeh Pahlavani

2014-01-01T23:59:59.000Z

389

The critical tension in the Cascading DGP model  

E-Print Network [OSTI]

We study the behaviour of weak gravitational fields in the 6D Cascading DGP model using a bulk-based approach. To deal with the ambiguity in the thin limit of branes of codimension higher than one, we consider a specific regularization of the internal structure of the branes where the 5D brane can be considered thin with respect to the 4D one. We consider the solutions corresponding to pure tension sources on the 4D brane, and study perturbations at first order around these background solutions. We adopt a 4D scalar-vector-tensor decomposition, and focus on the scalar sector of perturbations. We show that, in a suitable 4D limit, the trace part of the 4D metric perturbations obeys a decoupled equation which suggests that it is a ghost for background tensions smaller than a critical tension, while it is a healthy field otherwise. We give a geometrical interpretation of the existence of the critical tension and of the reason why the relevant field is a ghost or not depending on the background tension. We howeve...

Sbisà, Fulvio

2014-01-01T23:59:59.000Z

390

Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers  

SciTech Connect (OSTI)

We report divergence, astigmatism and M2 measurements of quantum cascade lasers (QCL) with an emission wavelength of 8.77?m. Emission profiles from the QCL facet showed divergence angles of 62° and 32° FWHM ± 2° for the fast and slow axes, respectively. The observation of far field structure superimposed on the fast axes profiles was attributed to the position of the QCL die with respect to the edge of the laser submount, emphasizing the need for careful placement. Two diffraction-limited Germanium aspheric microlenses were designed and fabricated to efficiently collect, collimate, and focus QCL emission. A confocal system comprised of these lenses was used to measure the beam propagation figure of merit (M2) yielding 1.8 and 1.2 for the fast and slow axes, respectively. Astigmatism at the exit facet was calculated to be about 4 ?m, or less than half a wave. To the best of our knowledge, this is the first experimental measurement of astigmatism and M2 reported for mid-IR QCLs.

Krishnaswami, Kannan; Bernacki, Bruce E.; Cannon, Bret D.; Ho, Nicolas; Anheier, Norman C.

2008-02-15T23:59:59.000Z

391

Method for recovering power according to a cascaded rankine cycle by gasifying liquefied natural gas and utilizing the cold potential  

SciTech Connect (OSTI)

The present invention discloses a method for recovering effective energy as power between liquefied natural gas and a high temperature source by cascading two kinds of Rankine cycles when the liquefied natural gas is re-gasified. The method is characterized in that a first medium performs a first Rankine cycle with the liquefied natural gas as a low temperature source, the first medium being mainly a mixture of hydrocarbons having 1-6 carbon atoms or a mixture of halogenated hydrocarbons of boiling points close to those of said hydrocarbons, the first medium having compositions according to which the vapor curve of gasifying the liquefied natural gas substantially corresponds to the low pressure cooling curve of the first medium, the power generated thereby is recovered by a first turbine during the first Rankine cycle, a second medium having a higher boiling point than said first medium performs a second Rankine cycle with part of said first Rankine cycle as the low temperature source, the second medium, being a single hydrocarbon component having 1-6 carbon atoms or a mixture thereof, a single halogenated hydrocarbon whose boiling point is close to that of this hydrocarbon or a mixture thereof, or ammonia, whose low pressure cooling curve substantially corresponds to the vapor curve of the high pressure first medium, said first and second Rankine cycles are cascaded, and a second turbine is disposed to recover power during the second Rankine cycle.

Matsumoto, O.; Aoki, I.

1984-04-24T23:59:59.000Z

392

Results of rapid pyrolysis experiments using eastern US oil shale in the Livermore solid-recycle retort  

SciTech Connect (OSTI)

Over the past several years Lawrence Livermore National Laboratory has operated a 2-ton/day pilot-scale solid-recycle system for the study of oil shale retorting under rapid-pyrolysis conditions. Results of processing eastern US New Albany oil shale are presented and compared with results obtained previously using two western US Green River oil shales. The retort consists of a cascading mixer and plug-flow soak-tank pyrolyzer with an air lift pipe and cascading-bed combustor. In the solid-recycle system, spent shale leaving the pyrolyzer is burned in the lift and cascading-bed combustor and then returned to the retort to heat the incoming raw shale. In laboratory experiments, when raw shale is rapidly heated in a fluidized bed of sand, oil yields above those of Fischer assay are obtained. In the present experiments, hot-recycled shale is used as the heat-carrying media, resulting in oil yields comparable to those obtained from Fischer assay. The distribution and composition of solid, oil, and gas throughout the recycle system is reported for the three shales studied. The distribution of sulfur and nitrogen during processing Green River oil shale has been the focus of environmental studies at LLNL. Eastern oil shale contains 5 to 10 times more sulfur and approximately the same amount of nitrogen as western oil shale. The high sulfur content coupled with low carbonate mineral concentrations results in significant sulfur releases in the combustor-gas, compared with trace releases for western shale. Iron oxide in the recycled solid was found to effectively scrub H/sub 2/S from the pyrolysis gas for both western and eastern shales. From 0.4 to 3% of the raw shale nitrogen is released as NO/sub x/ in the combustor-gas for western shale. Releases for New Albany shale are one-tenth these levels. 8 refs., 9 figs., 7 tabs.

Cena, R.J.; Taylor, R.W.

1986-11-01T23:59:59.000Z

393

Recent developments of the cascade-exciton model of nuclear reactions  

SciTech Connect (OSTI)

Recent developments of the Cascade-Exciton Model (CEM) of nuclear reactions are described. The improved cascade-exciton model as implemented in the code CEM97 differs from the CEM95 version by incorporating new approximations for the elementary cross sections used in the cascade, using more precise values for nuclear masses and pairing energies, using corrected systematics for the level-density parameters, and several other refinements. We have improved algorithms used in many subroutines, decreasing the computing time by up to a factor of 6 for heavy targets. We describe a number of further improvements and changes to CEM97, motivated by new data on isotope production measured at GSI. This leads us to CEM2k, a new version of the CEM code. CEM2k has a longer cascade stage, less preequilibrium emission, and evaporation from more highly excited compound nuclei compared to earlier versions. CEM2k also has other improvements and allows us to better model neutron, radionuclide, and gas production in ATW spallation targets. The increased accuracy and predictive power of the code CEM2k are shown by several examples. Further necessary work is outlined. KEYWORDS: Intranuclear cascade, preequilibrium, evaporation, and fission reactions, Monte Carlo simulations, cascade-exciton model, particle spectra, spallation and fission cross sections, GSI data

Mashnik, S. G. (Stepan G.); Sierk, A. J. (Arnold J.)

2001-01-01T23:59:59.000Z

394

Astrophysical Gyrokinetics: Kinetic and Fluid Turbulent Cascades In Magentized Weakly Collisional Plasmas  

SciTech Connect (OSTI)

This paper presents a theoretical framework for understanding plasma turbulence in astrophysical plasmas. It is motivated by observations of electromagnetic and density fluctuations in the solar wind, interstellar medium and galaxy clusters, as well as by models of particle heating in accretion disks. All of these plasmas and many others have turbulentmotions at weakly collisional and collisionless scales. The paper focuses on turbulence in a strong mean magnetic field. The key assumptions are that the turbulent fluctuations are small compared to the mean field, spatially anisotropic with respect to it and that their frequency is low compared to the ion cyclotron frequency. The turbulence is assumed to be forced at some system-specific outer scale. The energy injected at this scale has to be dissipated into heat, which ultimately cannot be accomplished without collisions. A kinetic cascade develops that brings the energy to collisional scales both in space and velocity. The nature of the kinetic cascade in various scale ranges depends on the physics of plasma fluctuations that exist there. There are four special scales that separate physically distinct regimes: the electron and ion gyroscales, the mean free path and the electron diffusion scale. In each of the scale ranges separated by these scales, the fully kinetic problem is systematically reduced to a more physically transparent and computationally tractable system of equations, which are derived in a rigorous way. In the "inertial range" above the ion gyroscale, the kinetic cascade separates into two parts: a cascade of Alfvenic fluctuations and a passive cascade of density and magnetic-fieldstrength fluctuations. The former are governed by the Reduced Magnetohydrodynamic (RMHD) equations at both the collisional and collisionless scales; the latter obey a linear kinetic equation along the (moving) field lines associated with the Alfvenic component (in the collisional limit, these compressive fluctuations become the slow and entropy modes of the conventional MHD). In the "dissipation range" below ion gyroscale, there are again two cascades: the kinetic-Alfven-wave (KAW) cascade governed by two fluid-like Electron Reduced Magnetohydrodynamic (ERMHD) equations and a passive cascade of ion entropy fluctuations both in space and velocity. The latter cascade brings the energy of the inertial-range fluctuations that was Landau-damped at the ion gyroscale to collisional scales in the phase space and leads to ion heating. The KAWenergy is similarly damped at the electron gyroscale and converted into electron heat. Kolmogorov-style scaling relations are derived for all of these cascades. The relationship between the theoretical models proposed in this paper and astrophysical applications and observations is discussed in detail.

A.A. Schekochihin, S.C. Cowley, W. Dorland, G.W. Hammett, G.G. Howes, E. Quataert, and T. Tatsuno

2009-04-23T23:59:59.000Z

395

Stabilization, Injection and Control of Quantum Cascade Lasers, and Their Appli-cation to Chemical Sensing in the Infrared  

SciTech Connect (OSTI)

Quantum cascade lasers (QCLs) are a relatively new type of semiconductor laser operating in the mid- to long-wave infrared. These monopolar multilayered quantum well structures can be fabricated to operate anywhere between 3.5 microns and 20 microns, which includes the molecular fingerprint region of the in-frared. This makes them an ideal choice for infrared chemical sensing, a topic of great interest at present. Frequency stabilization and injection locking increase the utility of QCLs. We present results of locking quantum cascade lasers to optical cavities, achieving relative linewidths down to 5.6 Hz. We report injec-tion locking of one distributed feedback grating QCL with light from a similar QCL, demonstrating capture ranges of up to ±500 MHz, and suppression of amplitude modulation by up to 49 dB. We also present various cavity-enhanced chemical sensors employing the frequency stabilization techniques developed, in-cluding the resonant sideband technique known as Nice-Ohms. Sensitivities of 9.7 x 10-11 cm-1 Hz-1/2 have been achieved in nitrous oxide.

Taubman, Matthew S.; Myers, Tanya L.; Cannon, Bret D.; Williams, Richard M.

2004-12-01T23:59:59.000Z

396

Measurement of Broad Absorption Features Using a Tunable External Cavity Quantum Cascade Laser  

SciTech Connect (OSTI)

We demonstrate the use of a tunable external cavity quantum cascade laser system for measurement of broad absorption features in the mid-infrared spectral region. The thermoelectrically cooled external cavity laser was tuned over a 65 cm-1 range centered at 8.7 microns using stepper motor control. Pulsing the laser at a high duty cycle provided 3-5 mW average output power over the tuning range, and enabled phase-sensitive detection of amplitude-modulated signals. We used the laser system to measure the absorption spectra of Freon-125 using a Herriott cell. In addition, the absorption spectrum of water in the laboratory air was measured. The measurements showed excellent agreement with reference spectra, in both wavelength and amplitude. The measured scan resolution of 0.14 cm-1 is suitable for measurement of the absorption features of complex molecules as well as simple molecules with atmospherically broadened lines. We discuss the limits to the scan resolution due to effects of spectral chirp and mode-hops during pulsed operation.

Phillips, Mark C.; Myers, Tanya L.; Wojcik, Michael D.; Cannon, Bret D.; Taubman, Matthew S.; Scott, David C.

2007-09-25T23:59:59.000Z

397

Enhancement of existing geothermal resource utilization by cascading to intensive aquaculture  

SciTech Connect (OSTI)

A demonstration high rate aquaculture production system utilizing a cascaded geothermal resource was designed, constructed and operated to fulfill the objectives of this project. Analysis of the energy and water balances for the system indicated that the addition of an Aquaculture Facility expanded the use of the existing resource. This expanded use in no way affected the up- stream processes. Analysis of the system`s energy and water requirements indicated that the present resource was under-utilized and could be expanded. Energy requirements appeared more limiting than water use, but the existing system could be expanded to a culture volume of 72,000 gal. This system would have a potential production capacity of 93,600 lb/yr with a potential market value of $280,00/yr. Based on the results of this study, the heat remaining in the geothermal fluid from one square foot of operating greenhouse is sufficient to support six gallons of culture water for a high density aquaculture facility. Thus, the over 1.5M ft{sup 2} of existing greenhouse space in New Mexico, has the potential to create an aquaculture industry of nearly 9M gal. This translates to an annual production potential of 11.7M lb with a market value of $35.lM.

Zachritz, W.H., II; Polka, R.; Schoenmackers

1996-04-01T23:59:59.000Z

398

Long wave infrared cavity-enhanced sensors using quantum cascade lasers  

SciTech Connect (OSTI)

Quantum cascade lasers (QCLs) are becoming well known as convenient and stable semiconductor laser sources operating in the mid- to long-wave infrared, and are able to be fabricated to operate virtually anywhere in the 3.5 to 25 micron region. This makes them an ideal choice for infrared chemical sensing, a topic of great interest at present, spanning at least three critical areas: national security, environmental monitoring and protection, and the early diagnosis of disease through breath analysis. There are many different laser-based spectroscopic chemical sensor architectures in use today, from simple direct detection through to more complex and highly sensitive systems. Many current sensor needs can be met by combining QCLs and appropriate sensor architectures, those needs ranging from UAV-mounted surveillance systems, through to larger ultra-sensitive systems for airport security. In this paper we provide an overview of various laser-based spectroscopic sensing techniques, pointing out advantages and disadvantages of each. As part of this process, we include our own results and observations for techniques under development at PNNL. We also present the latest performance of our ultra-quiet QCL control electronics now being commercialized, and explore how using optimized supporting electronics enables increased sensor performance and decreased sensor footprint for given applications.

Taubman, Matthew S.; Scott, David C.; Myers, Tanya L.; Cannon, Bret D.

2005-12-30T23:59:59.000Z

399

Geology and geothermal resources of the Santiam Pass area of the Oregon Cascade Range, Deschutes, Jefferson and Linn Counties, Oregon. Final report  

SciTech Connect (OSTI)

This open-file report presents the results of the Santiam Pass drilling program. The first phase of this program was to compile all available geological, geophysical and geothermal data for the Santiam Pass area and select a drill site on the basis of these data (see Priest and others, 1987a), A summary of the drilling operations and costs associated with the project are presented in chapter 1 by Hill and Benoit. An Overview of the geology of the Santiam Pass area is presented by Hill and Priest in chapter 2. Geologic mapping and isotopic age determinations in the Santiam Pass-Mount Jefferson area completed since 1987 are summarized in chapter 2. One of the more important conclusions reached in chapter 2 is that a minimum of 2 km vertical displacement has occurred in the High Cascade graben in the Santiam Pass area. The petrology of the Santiam Pass drill core is presented by Hill in chapter 3. Most of the major volcanic units in the core have been analyzed for major, minor, and trace element abundances and have been studied petrographically. Three K-Ar ages are interpreted in conjunction with the magnetostratigraphy of the core to show that the oldest rocks in the core are approximately 1.8 Ma. Geothermal and geophysical data collected from the Santiam Pass well are presented by Blackwell in chapter 4. The Santiam Pass well failed to penetrate beneath the zone of lateral groundwater flow associated with highly permeable Quaternary volcanic rocks. Calculated geothermal gradients range from about 50{degree}C/km at depth 700-900 m, to roughly 110{degree}C/km from 900 m to the bottom of the well at 929 m. Heat-flow values for the bottom part of the hole bracket the regional average for the High Cascades. Blackwell concludes that heat flow along the High Cascades axis is equal to or higher than along the western edge of the High Cascades.

Hill, B.E. [ed.

1992-10-01T23:59:59.000Z

400

Soliton compression to few-cycle pulses with a high quality factor by engineering cascaded quadratic nonlinearities  

Science Journals Connector (OSTI)

We propose an efficient approach to improve few-cycle soliton compression with cascaded quadratic nonlinearities by using an engineered multi-section structure of the nonlinear...

Zeng, Xianglong; Guo, Hairun; Zhou, Binbin; Bache, Morten

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Improving Soliton Compression Quality with Cascaded Nonlinearities by Engineered Multi-section Quasi-phase-matching Design  

Science Journals Connector (OSTI)

In few-cycle soliton generation with large compression factors using cascaded nonlinearities the pulse quality can be improved by engineering quasi-phase-matching structures. The...

Zeng, Xianglong; Guo, Hairun; Zhou, Binbin; Bache, Morten

402

Isotopic Ratio Measurements of Atmospheric Carbon Dioxide Using a 4.3 ?m Pulsed Quantum Cascade Laser  

Science Journals Connector (OSTI)

We report CO2 isotopic ratios (13C, 18O) measured in air using a pulsed quantum cascade laser at 2310 cm-1. Performance is...

Nelson, David; McManus, John B; Zahniser, Mark S; Tuzson, Bela; Emmenegger, Lukas

403

Time-Resolved Measurements of Near-Infrared Pulse Induced Ultrafast Optical Modulation of Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We temporally resolve ultrafast modulation of quantum cascade lasers (QCLs) using a near-infrared pump mid-infrared probe technique. We compare interband and intersubband transition...

Cai, Hong; Liu, Sheng; Lalanne, Elaine; Guo, Dingkai; Chen, Xing; Wang, Xiaojun; Choa, Fow-Sen; Johnson, Anthony M

404

A Novel Integrated TPV Power Generation System Based on a Cascaded Radiant Burner  

Science Journals Connector (OSTI)

A cascaded radiant burner has been developed and based on this burner a novel integrated TPV system has been built. In this system low bandgap GaSb cells and silicon concentrator solar cells are employed integratedly. The unique cascaded radiant burner consists of two different radiators which cascade?emit two streams of radiation with different spectra. The two different radiators are arranged in tandem with their surface temperatures being different as well. Two streams of radiation output are matched respectively to the bandgaps of silicon cells and GaSb cells. Thus one stream of radiation output illuminates silicon concentrator solar cells while the other drives low bandgap GaSb cells in the integrated system. In this work the combustion performance of the cascaded radiant burner was investigated at varying degrees of exhaust heat recuperation. The electrical output characteristics of both silicon concentrator solar cells and GaSb cells in the gas combustion?driven TPV system were measured under various operating conditions. It is shown that this innovative design considerably increases the TPV system efficiency due to the cascaded utilization of heat released during natural gas combustion and the optimized thermal management.

K. Qiu; A. C. S. Hayden

2004-01-01T23:59:59.000Z

405

Monte-Carlo Modeling of Parameters of a Subcritical Cascade Reactor Based on MSBR and LMFBR Technologies  

E-Print Network [OSTI]

Parameters of a subcritical cascade reactor driven by a proton accelerator and based on a primary lead-bismuth target, main reactor constructed analogously to the molten salt breeder (MSBR) reactor core and a booster-reactor analogous to the core of the BN-350 liquid metal cooled fast breeder reactor (LMFBR). It is shown by means of Monte-Carlo modeling that the reactor under study provides safe operation modes (k_{eff}=0.94-0.98), is apable to transmute effectively radioactive nuclear waste and reduces by an order of magnitude the requirements on the accelerator beam current. Calculations show that the maximal neutron flux in the thermal zone is 10^{14} cm^{12}\\cdot s^_{-1}, in the fast booster zone is 5.12\\cdot10^{15} cm^{12}\\cdot s{-1} at k_{eff}=0.98 and proton beam current I=2.1 mA.

Bznuni, S A; Zhamkochyan, V M; Polanski, A; Sosnin, A N; Khudaverdyan, A H

2001-01-01T23:59:59.000Z

406

The Effect of Gas Absorption on the Scattered Radiation in the Solar Almucantar: Results of Numerical Simulation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Gas Absorption on the Gas Absorption on the Scattered Radiation in the Solar Almucantar: Results of Numerical Simulation T. Yu. Chesnokova, K. M. Firsov, I. M. Nasrtdinov, S. M. Sakerin, V. V. Veretennikov, and T. B. Zhuravleva Institute of Atmospheric Optics Tomsk, Russia Introduction The methods for reconstruction of the aerosol optical characteristics (e.g., aerosol size distribution, and single-scattering albedo) from diffuse and direct radiation measured in the solar almucantar has been widely used during the last decade. The photometers with filters in the "atmospheric transparency windows" in the wavelength range 0.4 to 1 m were applied for measurements. Usually it was assumed that one could neglect the molecular absorption of the measured diffuse radiation. Further development

407

Studying effects of storage types on performance of CNG filling stations  

Science Journals Connector (OSTI)

At CNG filling station, compressed natural gas must be stored in storage system in order to make the utilization of the station more efficient. There are two systems for storing natural gas namely buffer and cascade storage systems. In buffer storage, CNG is stored at single high-pressure reservoirs. The cascade storage system is usually divided into three reservoirs, generally termed low, medium and high-pressure reservoirs. In current study, based on first and second laws of thermodynamics, conversation of mass and real gas assumptions, a theoretical analysis has been developed to study effects of reservation type on performance of CNG filling stations and filling process. Considering the same final natural gas vehicle cylinder (NGV) on-board in-cylinder pressure for both storage systems, the results show that each storage type has advantages over the other. The best configuration should be selected by balancing these advantages.

Mahmood Farzaneh-Gord; Mahdi Deymi-Dashtebayaz; Hamid Reza Rahbari

2011-01-01T23:59:59.000Z

408

Blowing Ratio Effects on Film Cooling Effectiveness  

E-Print Network [OSTI]

The research focuses on testing the film cooling effectiveness on a gas turbine blade suction side surface. The test is performed on a five bladed cascade with a blow down facility. Four different blowing ratios are used in this study, which are 0...

Liu, Kuo-Chun

2010-01-14T23:59:59.000Z

409

Effect of Fuel Wobbe Number on Pollutant Emissions from Advanced Technology Residential Water Heaters: Results of Controlled Experiments  

SciTech Connect (OSTI)

The research summarized in this report is part of a larger effort to evaluate the potential air quality impacts of using liquefied natural gas in California. A difference of potential importance between many liquefied natural gas blends and the natural gas blends that have been distributed in California in recent years is the higher Wobbe number of liquefied natural gas. Wobbe number is a measure of the energy delivery rate for appliances that use orifice- or pressure-based fuel metering. The effect of Wobbe number on pollutant emissions from residential water heaters was evaluated in controlled experiments. Experiments were conducted on eight storage water heaters, including five with “ultra low-NO{sub X}” burners, and four on-demand (tankless) water heaters, all of which featured ultra low-NO{sub X} burners. Pollutant emissions were quantified as air-free concentrations in the appliance flue and fuel-based emission factors in units of nanogram of pollutant emitter per joule of fuel energy consumed. Emissions were measured for carbon monoxide (CO), nitrogen oxides (NO{sub X}), nitrogen oxide (NO), formaldehyde and acetaldehyde as the water heaters were operated through defined operating cycles using fuels with varying Wobbe number. The reference fuel was Northern California line gas with Wobbe number ranging from 1344 to 1365. Test fuels had Wobbe numbers of 1360, 1390 and 1420. The most prominent finding was an increase in NO{sub X} emissions with increasing Wobbe number: all five of the ultra low-NO{sub X} storage water heaters and two of the four ultra low-NO{sub X} on-demand water heaters had statistically discernible (p<0.10) increases in NO{sub X} with fuel Wobbe number. The largest percentage increases occurred for the ultra low-NO{sub X} water heaters. There was a discernible change in CO emissions with Wobbe number for all four of the on-demand devices tested. The on-demand water heater with the highest CO emissions also had the largest CO increase with increasing fuel Wobbe number.

Rapp, VH; Singer, BC

2014-03-01T23:59:59.000Z

410

Results of the European Commission Marina II Study Part II—effects of discharges of naturally occurring radioactive material  

Science Journals Connector (OSTI)

Enhanced levels of naturally occurring radioactive materials (NORM) are produced through various industrial operations and may lead to discharges to the marine environment. A recent study, called MARINA II, carried out for the European Commission considered discharges of radionuclides from the NORM industries to north European marine waters and their consequences. There are two main sources that were considered in the study. The use of phosphogypsum during the production of phosphoric acid by the fertiliser industry and the pumping of oil and gas from the continental shelf in the North Sea which produces large quantities of water contaminated with enhanced levels of naturally occurring radionuclides. Discharges of alpha emitting radionuclides from these two industries have contributed significantly to the total input of alpha emitters to north European waters over the period 1981–2000 (data were not available prior to 1981). Discharges due to the use of phosphogypsum have declined since the early 1990s and are now very low. Discharges from the oil and gas industries stabilised in the second half of the 1990s and are now the major contributor to alpha discharges to the region. As most European countries do not report discharges of radioactivity with the water produced during extraction, there is considerable uncertainty in the discharges used in the study. The impact of the discharges has been estimated both in terms of the effect on non-human biota and the radiological impact for people. In the 1980s the radiation dose rates to marine biota in the region around a phosphate plant on the north-west coast of England were as high due to the discharges from the phosphate plant as those near to the Sellafield reprocessing plant due to its discharges. In recent years the additional dose to marine biota in this region due to the past NORM discharges is of the same order of magnitude as the natural background. The collective dose rate was estimated to determine the radiological impact on people. The peak collective dose rate from the NORM industries occurred in 1984 and was just over 600 manSv y?1. The collective dose rate fell with time as discharges from the phosphate industry reduced and was estimated as under 200 manSv y?1 in 2000.

M. Betti; L. Aldave de las Heras; A. Janssens; E. Henrich; G. Hunter; M. Gerchikov; M. Dutton; A.W. van Weers; S. Nielsen; J. Simmonds; A. Bexon; T. Sazykina

2004-01-01T23:59:59.000Z

411

First search for extraterrestrial neutrino-induced cascades with IceCube  

SciTech Connect (OSTI)

We report on the first search for extraterrestrial neutrino-induced cascades in IceCube.The analyzed data were collected in the year 2007 when 22 detector strings were installed and operated. We will discuss the analysis methods used to reconstruct cascades and to suppress backgrounds. Simulated neutrino signal events with a E-2 energy spectrum, which pass the background rejection criteria, are reconstructed with a resolution Delta(log E) ~;; 0.27 in the energy range from ~;; 20 TeV to a few PeV. We present the range of the diffuse flux of extra-terrestrial neutrinos in the cascade channel in IceCube within which we expect to be able to put a limit.

IceCube Collaboration; Kiryluk, Joanna

2009-05-22T23:59:59.000Z

412

Cascaded H-bridge inverter motor drives for hybrid electric vehicle applications  

Science Journals Connector (OSTI)

This paper presents the asymmetric cascaded H-bridge multilevel inverter for electric vehicles (EV) and hybrid electric vehicles (HEV) applications. Currently available power inverter systems for HEVs use a DC-DC boost converter to boost the battery voltage for a traditional three-phase inverter. The present HEV drive inverters have low power density, are expensive, and have low efficiency because they need a bulky inductor. Asymmetric cascaded H-bridge multilevel inverter design for EV and HEV applications without the use of inductors to output a boosted AC voltage is proposed in this paper. Traditionally, each H-bridge needs a DC power supply having equal values of DC power sources. The proposed design uses the asymmetric cascaded multilevel inverter using non-equal DC power sources based on specified ratios. A fundamental switching scheme is used to do modulation control and to produce a seven-level phase voltage.

P. Renuga; T. Prathiba

2012-01-01T23:59:59.000Z

413

Excitonic enhancement of nonradiative energy transfer to bulk silicon with the hybridization of cascaded quantum dots  

SciTech Connect (OSTI)

We report enhanced sensitization of silicon through nonradiative energy transfer (NRET) of the excitons in an energy-gradient structure composed of a cascaded bilayer of green- and red-emitting CdTe quantum dots (QDs) on bulk silicon. Here NRET dynamics were systematically investigated comparatively for the cascaded energy-gradient and mono-dispersed QD structures at room temperature. We show experimentally that NRET from the QD layer into silicon is enhanced by 40% in the case of an energy-gradient cascaded structure as compared to the mono-dispersed structures, which is in agreement with the theoretical analysis based on the excited state population-depopulation dynamics of the QDs.

Yeltik, Aydan; Guzelturk, Burak; Akhavan, Shahab [Department of Physics and Department of Electrical and Electronics Engineering, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey)] [Department of Physics and Department of Electrical and Electronics Engineering, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Ludwig Hernandez-Martinez, Pedro; Volkan Demir, Hilmi, E-mail: volkan@stanfordalumni.org [Department of Physics and Department of Electrical and Electronics Engineering, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Luminous Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)

2013-12-23T23:59:59.000Z

414

SIMULATION MODELING OF AN ENHANCED LOW-EMISSION SWIRL-CASCADE BURNER  

SciTech Connect (OSTI)

The research team was formed. The advanced CFDRC-CHEMKIN software package was installed on a SUN-SPARC dual processor workstation. The literature pertinent to the project was collected. The physical model was set and all parameters and variables were identified. Based on the physical model, the geometric modeling and grid generation processes were performed using the CFD-GEOM (Interactive Geometric Modeling and Grid Generation software). A total number of 11160 cells (248 x 45) were generated to numerically model the baseline, cascaded, swirling, and swirling-cascaded flames. With the cascade being added to the jet, the geometric complexity of the problem increased; which required multi-domain structured grid systems to be connected and matched on the boundaries.

Ala Qubbaj

2003-04-01T23:59:59.000Z

415

ARRA: Reconfiguring Power Systems to Minimize Cascading Failures - Models and Algorithms  

SciTech Connect (OSTI)

Building on models of electrical power systems, and on powerful mathematical techniques including optimization, model predictive control, and simluation, this project investigated important issues related to the stable operation of power grids. A topic of particular focus was cascading failures of the power grid: simulation, quantification, mitigation, and control. We also analyzed the vulnerability of networks to component failures, and the design of networks that are responsive to and robust to such failures. Numerous other related topics were investigated, including energy hubs and cascading stall of induction machines

Dobson, Ian [Iowa State University] [Iowa State University; Hiskens, Ian [Unversity of Michigan] [Unversity of Michigan; Linderoth, Jeffrey [University of Wisconsin-Madison] [University of Wisconsin-Madison; Wright, Stephen [University of Wisconsin-Madison] [University of Wisconsin-Madison

2013-12-16T23:59:59.000Z

416

Gamma-strength functions in 60Ni from two-step cascades following proton capture  

E-Print Network [OSTI]

The two-step cascade method previously used in neutron capture experiments is now applied to a proton capture reaction. The spectrum of two-step cascades populating the first 2+ level of 60Ni has been measured with 59Co(p,2gamma)60Ni reaction. The simulation technique used for the spectrum analysis allows one to reveal the range of possible shapes of both E1 and M1 gamma-strength functions. The low-energy enhancement previously observed in 3He induced reactions is seen to appear in M1 strength functions of 60Ni.

A. Voinov; S. M. Grimes; C. R. Brune; M. Guttormsen; A. C. Larsen; T. N. Massey; A. Schiller; S. Siem

2009-11-10T23:59:59.000Z

417

16 - Microcavities and quantum cascade laser structures based on silicon–germanium (SiGe) nanostructures  

Science Journals Connector (OSTI)

Abstract: This chapter discusses two types of Si-based light-emitting devices based on Ge quantum dots in optical microcavities and SiGe quantum cascade (QC) structures. After reviewing various solutions for Si-based light-emitting devices, the chapter describes the method to enhance light emission from Ge dots through embedding them into optical microcavities. It then reviews SiGe quantum cascade laser (QCL) structures on issues of material growth, electroluminescence from SiGe QC structures, n-type SiGe QC structures, and waveguides for SiGe QCLs.

J. Xia; Y. Shiraki; J. Yu

2011-01-01T23:59:59.000Z

418

Four-photon cascade from quadexcitons in a single GaAs quantum dot  

Science Journals Connector (OSTI)

We demonstrate the generation of temporally correlated four photons emitted by the cascade recombination of a quadexciton in a self-assembled GaAs quantum dot (QD) by performing single photon correlation measurements. The cascade decay of the quadexciton involves a triexciton, a biexciton, and an exciton. The emissions of these states are identified in the photoluminescence (PL) spectrum of the QD by cross-correlation measurements. Polarization-resolved cross-correlation measurements show that the polarizations of the four photons are partly correlated. Radiative, nonradiative, and polarization flipping rates in the QD are estimated from the bunching visibilities of the cross-correlation measurements and the PL lifetimes.

Y. Arashida; Y. Ogawa; F. Minami

2011-09-12T23:59:59.000Z

419

A modular architecture for multi-channel external cavity quantum cascade laser-based chemical sensors: a systems approach  

SciTech Connect (OSTI)

A multi-channel laser-based chemical sensor platform is presented, in which a modular architecture allows the exchange of complete sensor channels without disruption to overall operation. Each sensor channel contains custom optical and electronics packages, which can be selected to access laser wavelengths, interaction path lengths and modulation techniques optimal for a given application or mission. Although intended primarily to accommodate mid-infrared (MIR) external cavity quantum cascade lasers (ECQCLs)and astigmatic Herriott cells, channels using visible or near infrared (NIR) lasers or other gas cell architectures can also be used, making this a truly versatile platform. Analog and digital resources have been carefully chosen to facilitate small footprint, rapid spectral scanning, ow-noise signal recovery, failsafe autonomous operation, and in-situ chemometric data analysis, storage and transmission. Results from the demonstration of a two-channel version of this platform are also presented.

Taubman, Matthew S.; Myers, Tanya L.; Bernacki, Bruce E.; Stahl, Robert D.; Cannon, Bret D.; Schiffern, John T.; Phillips, Mark C.

2012-04-01T23:59:59.000Z

420

Femtosecond measurements of near-infrared pulse induced mid-infrared transmission modulation of quantum cascade lasers  

SciTech Connect (OSTI)

We temporally resolved the ultrafast mid-infrared transmission modulation of quantum cascade lasers (QCLs) using a near-infrared pump/mid-infrared probe technique at room temperature. Two different femtosecond wavelength pumps were used with photon energy above and below the quantum well (QW) bandgap. The shorter wavelength pump modulates the mid-infrared probe transmission through interband transition assisted mechanisms, resulting in a high transmission modulation depth and several nanoseconds recovery lifetime. In contrast, pumping with a photon energy below the QW bandgap induces a smaller transmission modulation depth but much faster (several picoseconds) recovery lifetime, attributed to intersubband transition assisted mechanisms. The latter ultrafast modulation (>60?GHz) could provide a potential way to realize fast QCL based free space optical communication.

Cai, Hong; Liu, Sheng [Department of Physics, University of Maryland, Baltimore County (UMBC), Baltimore, Maryland 21250 (United States); Center for Advanced Studied in Photonics Research (CASPR), UMBC, Baltimore, Maryland 21250 (United States); Lalanne, Elaine [Center for Advanced Studied in Photonics Research (CASPR), UMBC, Baltimore, Maryland 21250 (United States); Guo, Dingkai; Chen, Xing; Choa, Fow-Sen [Center for Advanced Studied in Photonics Research (CASPR), UMBC, Baltimore, Maryland 21250 (United States); Department of CSEE, UMBC, Baltimore, Maryland 21250 (United States); Wang, Xiaojun [AdTech Optics, Inc., City of Industry, California 91748 (United States); Johnson, Anthony M., E-mail: amj@umbc.edu [Department of Physics, University of Maryland, Baltimore County (UMBC), Baltimore, Maryland 21250 (United States); Center for Advanced Studied in Photonics Research (CASPR), UMBC, Baltimore, Maryland 21250 (United States); Department of CSEE, UMBC, Baltimore, Maryland 21250 (United States)

2014-05-26T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Investigation of the thermal regime and geologic history of the Cascade volcanic arc: First phase of a program for scientific drilling in the Cascade Range  

SciTech Connect (OSTI)

A phased, multihole drilling program with associated science is proposed as a means of furthering our understanding of the thermal regime and geologic history of the Cascade Range of Washington, Oregon, and northern California. The information obtained from drilling and ancillary geological and geophysical investigations will contribute to our knowledge in the following general areas: (1) the magnitude of the regional background heat flow of parts of the Quaternary volcanic belt dominated by the most abundant volcanic rock types, basalt and basaltic andesite; (2) the nature of the heat source responsible for the regional heat-flow anomaly; (3) the characteristics of the regional hydrothermal and cold-water circulation; the rates of volcanism for comparison with models for the rate and direction of plate convergence of the Cascades; (5) the history of deformation and volcanism in the volcanic arc that can be related to subduction; (6) the present-day stress regime of the volcanic arc and the relation of these stresses to plate interactions and possible large earthquakes; and the current geometry of the subducted oceanic plate below the Cascade Range and the relationship of the plate to the distribution of heat flow, Quaternary volcanism, and Quaternary deformation. Phase I research will be directed toward a detailed investigation of the Santiam Pass segment. In concert with the Santiam Pass research, a detailed study of the nearby Breitenbush Hot Springs area is also recommended as a component of Phase I. The object of the Breitenbush research is to study one of the hottest known Cascade hydrothermal systems, which coincidentally also has a good geological and geophysical data base. A coordinated program of drilling, sampling, subsurface measurements, and surface surveys will be associated with the drilling of several holes.

Priest, G.R.

1987-01-01T23:59:59.000Z

422

hal-00135292,version1-7Mar2007 Photovoltaic Probe of Cavity Polaritons in a Quantum Cascade Structure  

E-Print Network [OSTI]

hal-00135292,version1-7Mar2007 Photovoltaic Probe of Cavity Polaritons in a Quantum Cascade and a photonic mode of a planar microcavity has been detected by angle-resolved photovoltaic measure- ments polaritons in angle-resolved photovoltaic measurements, performed on a quan- tum cascade (QC) structure

Boyer, Edmond

423

Abstract-The ability of cascaded H-bridge multilevel inverter drives (MLID) to operate under faulty condition including AI-  

E-Print Network [OSTI]

for electric drive application have been discussed in [1]. The cascaded MLID is a general fit for large automotive all-electric drives because of the high VA rating possible and because it uses several dc voltage-phase cascaded multilevel inverter drive for an electric vehicle is illustrated in Fig. 1. The series of H

Tolbert, Leon M.

424

1058 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 49, NO. 5, OCTOBER 2002 Charge Balance Control Schemes for Cascade  

E-Print Network [OSTI]

electric vehicle (HEV) motor drives. Multilevel converters: 1) can gen- erate near-sinusoidal voltages system. The cascade inverter is a natural fit for large automotive hybrid electric drives because it uses--Cascade inverter, hybrid electric vehicle, motor drive, multilevel converter, multilevel inverter. I. INTRODUCTION

Tolbert, Leon M.

425

Masting and trophic cascades: interplay between rowan trees, apple fruit moth, and their parasitoid in southern Norway  

E-Print Network [OSTI]

Masting and trophic cascades: interplay between rowan trees, apple fruit moth, and their parasitoid. 2004. Masting and trophic cascades: interplay between rowan trees, apple fruit moth of the dominant seed predator and its parasitoid. The apple fruit moth, Argyresthia conjugella Zeller, is a pre

426

The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the  

E-Print Network [OSTI]

The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the Solar Wind C02101 (2010)], we have incorporated in the heating model the energy cascade rate based on Iroshnikov scale. Since in steady state, the heating rate is essentially the same as the energy cascade rate

Ng, Chung-Sang

427

Performance analysis of the cascade impactor, the federal reference method PM 2.5 sampler, and the improve PM 2.5 sampler  

E-Print Network [OSTI]

documented problems with the cascade impactor and suspicions over its accuracy. In this thesis research, the collected PM fractions from the cascade impactor will be subjected to analysis by the Coulter Counter Multisizer to verify inaccuracies. The new FRM...

Buch, Usha-Maria

2012-06-07T23:59:59.000Z

428

A calculation of the number of muons at sea-level in a photon-electron cascade initiated by a primary photon of energy 1014eV  

Science Journals Connector (OSTI)

The muon component in a photon-electron cascade initiated...14...eV has been estimated for sea-level in the longitudinal development of the electromagnetic cascade. Two distinct possible processes of muon product...

N. Mishra

1966-01-11T23:59:59.000Z

429

Assessment of effectiveness of geologic isolation systems. Geologic-simulation model for a hypothetical site in the Columbia Plateau. Volume 2: results  

SciTech Connect (OSTI)

This report contains the input data and computer results for the Geologic Simulation Model. This model is described in detail in the following report: Petrie, G.M., et. al. 1981. Geologic Simulation Model for a Hypothetical Site in the Columbia Plateau, Pacific Northwest Laboratory, Richland, Washington. The Geologic Simulation Model is a quasi-deterministic process-response model which simulates, for a million years into the future, the development of the geologic and hydrologic systems of the ground-water basin containing the Pasco Basin. Effects of natural processes on the ground-water hydrologic system are modeled principally by rate equations. The combined effects and synergistic interactions of different processes are approximated by linear superposition of their effects during discrete time intervals in a stepwise-integration approach.

Foley, M.G.; Petrie, G.M.; Baldwin, A.J.; Craig, R.G.

1982-06-01T23:59:59.000Z

430

Rescuing ecosystems from extinction cascades through compensatory perturbations Sagar Sahasrabudhe & Adilson E. Motter  

E-Print Network [OSTI]

corresponds to the sole zero-population species at a stable target state (in addition to the primary removal state in addition to the one introduced by the primary removal. This forced removal drives the system. The statistics are for all cascades mitigated by a species removal in Fig. 2b of the paper. The rescue states

Shahriar, Selim

431

Global Optimization Methods for the Aerodynamic Shape Design of Transonic Cascades  

E-Print Network [OSTI]

Global Optimization Methods for the Aerodynamic Shape Design of Transonic Cascades T. Mengistu algorithms, namely Genetic Algorithm (GA) and Simulated Annealing (SA), have been applied to the aerodynamic reduction in total pressure loss by eliminating the passage shock. 1. INTRODUCTION Aerodynamic optimization

Neumaier, Arnold

432

To appear in The Electricity Journal, Dec. 2003 Cascading Failures: Survival vs. Prevention  

E-Print Network [OSTI]

1 To appear in The Electricity Journal, Dec. 2003 Cascading Failures: Survival vs. Prevention systems, more data collection, more data processing, load management, and more programs to promote, though the really big ones are not quite as infrequent as one might first expect. The North American

433

Analytic target cascading in simulation-based building design R. Choudharya,*, A. Malkawib  

E-Print Network [OSTI]

of an office building by posing the problem as a constrained non- linear optimization problem. Gero et al. [9] included energy efficiency in the context of other performance criteria and proposed a design optimizationAnalytic target cascading in simulation-based building design R. Choudharya,*, A. Malkawib , P

Papalambros, Panos

434

Wave Turbulence in Superfluid 4 Energy Cascades, Rogue Waves & Kinetic Phenomena  

E-Print Network [OSTI]

Outline Wave Turbulence in Superfluid 4 He: Energy Cascades, Rogue Waves & Kinetic Phenomena Conference, Chernogolovka, 3 August 2009 McClintock Efimov Ganshin Kolmakov Mezhov-Deglin Wave Turbulence in Superfluid 4 He #12;Outline Outline 1 Introduction Motivation 2 Modelling wave turbulence Need for models

Fominov, Yakov

435

A Novel Cross-Flow Cascade Packed Column Design and Simulation  

Science Journals Connector (OSTI)

A Novel Cross-Flow Cascade Packed Column Design and Simulation ... Thus the abundant area for gas flow will decrease gas-phase pressure drop, and it can allow operation at gas velocities above the flooding points of countercurrent packed columns. ...

Fengrong Chen; Rongqi Zhou; Zhanting Duan; Yumei Liu

1999-07-03T23:59:59.000Z

436

Abstract-A hybrid cascaded multilevel inverter application for renewable energy resources including a reconfiguration  

E-Print Network [OSTI]

be achieved by using the microgrid concept as discussed in [2]. Data center or telecommunication buildings an alternative topology of hybrid cascaded multilevel inverter applied to a low voltage dc microgrid, micro-turbine, wind turbine and fuel cell put forward many promising applications with high efficiency

Tolbert, Leon M.

437

A Hybrid Energy System Using Cascaded H-bridge Converter , Zhong Du2  

E-Print Network [OSTI]

schemes were developed to extract maximum wind power and charge/discharge the battery with fast dynamics proposes a hybrid energy system to integrate the variable-speed wind turbine, fuel cell, and battery using a cascaded H-bridge converter. One of the advantages of this topology is that it still can obtain

Tolbert, Leon M.

438

Method of making cascaded die mountings with springs-loaded contact-bond options  

DOE Patents [OSTI]

A cascaded die mounting device and method using spring contacts for die attachment, with or without metallic bonds between the contacts and the dies, is disclosed. One embodiment is for the direct refrigerant cooling of an inverter/converter carrying higher power levels than most of the low power circuits previously taught, and does not require using a heat sink.

Hsu, John S. (Oak Ridge, TN); Adams, Donald J. (Knoxville, TN); Su, Gui-Jia (Knoxville, TN); Marlino, Laura D. (Oak Ridge, TN); Ayers, Curtis W. (Kingston, TN); Coomer, Chester (Knoxville, TN)

2007-06-19T23:59:59.000Z

439

Quantum Cascade Lasers Tuned by Amorphous As2S3 Claddings Daniel L. Recht1  

E-Print Network [OSTI]

(roughly 5-20 µm) makes them a natural choice for trace gas sensing. The spectroscopic fingerprints of many). The output range of QCLs provides a natural solution to this problem. Trace gas sensing has thus beenQuantum Cascade Lasers Tuned by Amorphous As2S3 Claddings Daniel L. Recht1 , Zhijun Liu1

Arnold, Craig B.

440

Cascading uncertainty in climate change models and its implications for policy  

E-Print Network [OSTI]

Commentary Cascading uncertainty in climate change models and its implications for policy MARK, there are intrinsic problems with modelling natural systems (Cartwright 1983). This is because it is impossible). The original IPCC reports used simplistic assumption of greenhouse gas emissions over the next 100 years. From

Jones, Peter JS

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Evolving Cascades of Voting Feature Detectors for Vehicle Detection in Satellite Imagery  

E-Print Network [OSTI]

Evolving Cascades of Voting Feature Detectors for Vehicle Detection in Satellite Imagery Krzysztof method for detection of vehicles in satellite imagery which involves a large number of simple elementary features and multiple detectors trained by genetic programming. The complete detection system is com- posed

Fernandez, Thomas

442

Terahertz Time Domain Spectroscopy of Phonon-Depopulation Based Quantum Cascade Lasers  

SciTech Connect (OSTI)

A 3.1 THz phonon depopulation-based quantum-cascade-laser is investigated using terahertz time domain spectroscopy. A gain of 25 cm{sup -1} and absorption features due to the lower laser level being populated from a parasitic electronic channel are highlighted.

Rungsawang, R.; Dhillon, S. S.; Jukam, N.; Oustinov, D.; Madeo, J.; Tignon, J. [Laboratoire Pierre Aigrain, Ecole Normale Superieure, UMR8551 CNRS, UPMC Univ. Paris 6, F-75005 Paris (France); Colombelli, R. [Institut d'Electronique Fondamentale, Universite Paris Sud, UMR8622 CNRS, 91405 Orsay (France); Dean, P.; Salih, M.; Khanna, S. P.; Linfield, E.; Davies, A. G. [School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT (United Kingdom)

2011-12-23T23:59:59.000Z

443

A tunable single-mode double-ring quantum-cascade laser  

Science Journals Connector (OSTI)

The design, fabrication and characterization of a monolithic double-ring quantum- cascade laser (DRQCL) are described. At a wavelength of 4.6 µm, we demonstrate tunable, single-mode operation of a DRQCL and use it as a source for spectroscopy of CO gas.

D Dhirhe; T J Slight; C C Nshii; C N Ironside

2012-01-01T23:59:59.000Z

444

Sensitive detection of methane and nitrous oxide isotopomers using a continuous wave quantum cascade laser  

Science Journals Connector (OSTI)

A continuous wave quantum cascade laser (QCL), operating near 8.1 ?m...4) and nitrous oxide (N2O) stable isotopes. Several rotational transitions of 14N2 16O, 15N14N16O, 14N2 18O,

G. Gagliardi; F. Tamassia; P. De Natale…

2002-06-01T23:59:59.000Z

445

Al composition dependency of interface phonon in the wurtzite quantum cascade laser  

Science Journals Connector (OSTI)

The interface (IF) phonons of the wurtzite quantum cascade lasers (QCL) are investigated using the transfer-...0.2Ga0.8N/GaN and Al0.15Ga0.85N/GaN QCLs, and two IF modes can be changed into other modes if their w...

Gui-chu Chen ???; Guang-han Fan ???

2010-05-01T23:59:59.000Z

446

Two-cascade acousto-optic dispersive delay line for ultrashort laser pulses  

SciTech Connect (OSTI)

An optical dispersive delay line for controlling the spectral composition and phase of ultrashort laser pulses is considered. To control independently the spectral amplitude and spectral phase of pulses, it is proposed to use the cascade arrangement of two acousto-optic cells with different control signals. (letters)

Molchanov, V Ya; Chizhikov, S I; Yushkov, K B [National University of Science and Technology 'MISIS', Moscow (Russian Federation)

2011-08-31T23:59:59.000Z

447

Intracavity Sensing via Compliance Voltage in an External Cavity Quantum Cascade Laser  

SciTech Connect (OSTI)

We demonstrate a technique for gas phase spectroscopy and sensing by detecting changes in compliance voltage of an external cavity quantum cascade laser due to intracavity absorption. The technique is characterized and used to measure the absorption spectrum of water vapor and Freon-134a.

Phillips, Mark C.; Taubman, Matthew S.

2012-07-01T23:59:59.000Z

448

Arrays and Cascades of Fluorescent Liquid-Liquid Waveguides: Broadband Light Sources for  

E-Print Network [OSTI]

Arrays and Cascades of Fluorescent Liquid-Liquid Waveguides: Broadband Light Sources) microchannel waveguides with liquid cores containing fluorescent dyes, excited by incident light from an external halogen bulb. Simultaneous use of multiple fluorophores in a common solution, in a single L2 light

Prentiss, Mara

449

Thermionic/AMTEC cascade converter concept for high-efficiency space power  

SciTech Connect (OSTI)

This paper presents trade studies that address the use of the thermionic/AMTEC cell--a cascaded, high-efficiency, static power conversion concept that appears well-suited to space power applications. Both the thermionic and AMTEC power conversion approaches have been shown to be promising candidates for space power. Thermionics offers system compactness via modest efficiency at high heat rejection temperatures, and AMTEC offers high efficiency at modest heat rejection temperature. From a thermal viewpoint the two are ideally suited for cascaded power conversion: thermionic heat rejection and AMTEC heat source temperatures are essentially the same. In addition to realizing conversion efficiencies potentially as high as 35--40%, such a cascade offers the following perceived benefits: survivability; simplicity; technology readiness; and technology growth. Mechanical approaches and thermal/electric matching criteria for integrating thermionics and AMTEC into a single conversion device are described. Focusing primarily on solar thermal space power applications, parametric trends are presented to show the performance and cost potential that should be achievable with present-day technology in cascaded thermionic/AMTEC systems.

Hagan, T.H. van; Smith, J.N. Jr. [General Atomics, San Diego, CA (United States); Schuller, M. [PL/VTP, Kirtland AFB, NM (United States)

1996-12-31T23:59:59.000Z

450

Modeling, Optimization, and Experimentation with a Two Stage Mixed Gas Cascaded Joule Thomson Cryoprobe  

E-Print Network [OSTI]

Modeling, Optimization, and Experimentation with a Two Stage Mixed Gas Cascaded Joule Thomson-stage Mixed Gas Joule Thomson (MGJT) cycle is capable of providing compact cooling for cryoprobes". A computational model of a commercially available two stage MGJT cryoprobe donated by American Medical Systems

Wisconsin at Madison, University of

451

2014 Results  

Broader source: Energy.gov [DOE]

In its inaugural year, 28 teams from U.S. and Canadian universities competed to design cost-effective Zero Energy Ready Homes for mainstream builders.  The core zero energy ready requirement...

452

High-resolution X-ray characterization of mid-IR Al0.45Ga0.55As/GaAs Quantum Cascade Laser structures  

Science Journals Connector (OSTI)

Abstract In this paper, the X-ray diffraction profiles of Quantum Cascade Laser (QCL) structures have been investigated. The examined structures were grown by molecular beam epitaxy. The crystallographic characterization was carried out using high resolution X-ray diffractometer. The information about thickness of individual layers and periodicity of the structures was derived from simulation of diffraction profiles calculated using dynamical diffraction theory. The influence of interface roughness on the shape of satellite peaks was studied. The particular attention has been paid to the analysis of the broadening of satellite peaks. The presented results show that broadening is due to the variation of thickness of individual layers.

J. Kubacka-Traczyk; I. Sankowska; O.H. Seeck; K. Kosiel; M. Bugajski

2014-01-01T23:59:59.000Z

453

Study of the effects of operating factors on the resulting producer gas of oil palm fronds gasification with a single throat downdraft gasifier  

Science Journals Connector (OSTI)

Abstract Malaysia has abundant but underutilized oil palm fronds. Although the gasification of biomass using preheated inlet air as a gasifying medium is considered an efficient and environmentally friendly method, previous studies were limited to certain types of biomass wastes and gasifier designs. Hence, the effects of preheating the gasifying air on oil palm fronds gasification in a single throat downdraft gasifier are presented in this paper. In addition, the effects of varying the flow rate of the gasifying air and the moisture content of the feedstock on the outputs of oil palm fronds gasification were studied. A response surface methodology was used for the design of the experiment and the analysis of the results. The results showed that preheating the gasifying air to 500 °C increased the concentrations of CO from 22.49 to 24.98%, that of CH4 from 1.98 to 2.87%, and that of H2 from 9.67 to 13.58% on dry basis in the producer gas at a 10% feedstock moisture content. Conversely, the dry basis concentrations of CO, CH4, and H2 decreased from 22.49, 1.98 and 9.67% to 12.01, 1.44 and 5.45%, respectively, as the moisture content increased from 10 to 20%. The airflow rate was also proven to significantly affect the quality of the resulting producer gas.

Fiseha M. Guangul; Shaharin A. Sulaiman; Anita Ramli

2014-01-01T23:59:59.000Z

454

A study of the drag on pole-supported cascades  

E-Print Network [OSTI]

AND CONSTRUCTION EXPERIMENTAL STUDIES AND RESULTS Plate Flutter and Pole Buffeting THEORETICAL RESULTS CURVED PLATE MODELS 17 21 VI. COMPARISON OF RESULTS AND EVOLUTION OF EMPIRICAL EQUATIONS 29 VII. CONCLUSIONS REFERENCES APPENDIX 35 36 LIST... OF FIGURES FIGURE PAGE Plate Orientation Wind Tunnel Facility Wind Tunnel Console Convention for Model Rotation Angle Interference Test 10 Variable Plate Angle Test Variable Plate Chord Test 12 13 10 ~ 12 ' Reynolds Number Test Aspect Ratio Test...

Baker, Sterling Jackson

2012-06-07T23:59:59.000Z

455

Constraint effects within R6 framework: Validation by small and large scale fracture test results for A533B-1 steel  

SciTech Connect (OSTI)

A framework for including constraint effects in the failure assessment diagram approach for fracture assessment was described in the 1994 ASME PVP conference. Constraint effects were treated by modifying the shape of the failure assessment curve. In their simplest form, the modifications involve only two parameters: one quantifying the magnitude of structural constraint which depends on geometry, crack size and loading; and the second quantifying the influence of constraint on fracture toughness. The validity of the framework is investigated in this paper by considering the results and associated analysis of both small and large scale upper shelf fracture toughness tests performed on an A533B-1 steel plate. The specimens had a range of crack-tip constraint conditions. The results demonstrated that: (i) Crack-tip constraint significantly influences the ductile fracture characteristics of this material, (ii) this influence is well quantified by the elastic T-stress or elastic-plastic Q-stress, and (iii) the modified R6 framework provides conservative assessments of fracture initiation.

Sherry, A.H.; Sharples, J.K.; Sanderson, D.J.; Gardner, L. [AEA Technology, Risley (United Kingdom). Technical Services Division; Ainsworth, R.A. [Nuclear Electric plc, Berkeley (United Kingdom)

1995-11-01T23:59:59.000Z

456

Pseudomorphic growth of InAs on misoriented GaAs for extending quantum cascade laser wavelength  

SciTech Connect (OSTI)

The authors have studied the impact of epilayer strain on the deposition of InAs/GaAs on (100) and (111)B with 2° offset toward<2-1-1> surfaces. Consequences of a 7% lattice mismatch between these orientations in the form of three-dimensional growth are less apparent for (111)B with 2° offset toward<2-1-1> surfaces compared to (100). By exploring a range of molecular beam epitaxy process parameters for InAs/GaAs growth and utilizing scanning electron microscopy, atomic force microscopy, and Raman spectroscopy to evaluate the quality of these strained layers, the authors develop empirical models that describe the influence of the process conditions in regards to surface roughness with >92% accuracy. The smoothest InAs/GaAs samples demonstrated average surface roughness of 0.08 nm for 10 ?m{sup 2} areas, albeit at very low deposition rates. The authors have found the most important process conditions to be substrate temperature and deposition rate, leading us to believe that controlling diffusion length may be the key to reducing defects in severely strained structures. InGaAs/AlGaAs quantum cascade laser structures were also produced on (111)B with 2° offset toward<2-1-1> to take advantage of the piezoelectric effect, and the modified laser transitions due to these effects were observed.

Meyer, Charles; Cheng, Emily; Grayer, Justin; Mueller, David; Triplett, Gregory; Roberts, Denzil [Department of Electrical and Computer Engineering, University of Missouri, 349 Engineering Building West, Columbia, Missouri 65201 (United States)] [Department of Electrical and Computer Engineering, University of Missouri, 349 Engineering Building West, Columbia, Missouri 65201 (United States); Graham, Samuel [Georgia Institute of Technology, Woodruff School of Mechanical Engineering, Atlanta, Georgia 30332 (United States)] [Georgia Institute of Technology, Woodruff School of Mechanical Engineering, Atlanta, Georgia 30332 (United States)

2013-11-15T23:59:59.000Z

457

Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3-D Endwall Contouring  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3 Blade Cascade with 3 - - D D Endwall Endwall Contouring Contouring Principal Investigator Principal Investigator Sumanta Acharya, Professor Sumanta Acharya, Professor Louisiana State University, Baton Rouge, Louisiana Louisiana State University, Baton Rouge, Louisiana Collaborators Collaborators Gazi Mahmood, Ph.D., Research Asqociate Gazi Mahmood, Ph.D., Research Asqociate Arun Saha, Ph.D., Research Associate Arun Saha, Ph.D., Research Associate Ross Gustafson, M.S. student Ross Gustafson, M.S. student SCIES Project 02 SCIES Project 02 - - 01 01 - - SR098 SR098 DOE COOPERATIVE AGREEMENT DE DOE COOPERATIVE AGREEMENT DE - - FC26 FC26 - - 02NT41431 02NT41431 Tom J. George, Program Manager, DOE/NETL

458

Laser frequency stabilization to excited state transitions using electromagnetically induced transparency in a cascade system  

SciTech Connect (OSTI)

We demonstrate laser frequency stabilization to excited state transitions using cascade electromagnetically induced transparency. Using a room temperature Rb vapor cell as a reference, we stabilize a first diode laser to the D{sub 2} transition and a second laser to a transition from the intermediate 5P{sub 3/2} state to a highly excited state with principal quantum number n=19-70. A combined laser linewidth of 280{+-}50 kHz over a 100 {mu}s time period is achieved. This method may be applied generally to any cascade system and allows laser stabilization to an atomic reference in the absence of a direct absorption signal.

Abel, R. P.; Mohapatra, A. K.; Bason, M. G.; Pritchard, J. D.; Weatherill, K. J.; Raitzsch, U.; Adams, C. S. [Department of Physics, Durham University, Rochester Building, South Road, Durham DH1 3LE (United Kingdom)

2009-02-16T23:59:59.000Z

459

Modeling and controller synthesis for the cascaded H-bridge multilevel active power filter with ADALINE-based identifiers  

Science Journals Connector (OSTI)

This paper presents the averaged state-space modeling and controller synthesis methodology for the cascaded H-bridge multilevel active power filters (CHB-APFs). ... compensation and dc-link stabilization among th...

Yang Han; Lin Xu; Muhammad Mansoor Khan; Chen Chen

2011-06-01T23:59:59.000Z

460

A Comparison on PSO Variants in Calculating HEPWM Switching Angles for a Cascaded H-Bridge Multilevel Inverter  

Science Journals Connector (OSTI)

This paper presents a comparison study on the application of various PSO algorithms in calculating the Pulse Width Modulation (PWM) switching angles of a cascaded H-bridge multilevel inverter. It aims to investig...

Norkharziana Mohd Nayan; Naziha Ahmad Azli…

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "resulting cascading effect" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Linewidth of a quantum-cascade laser assessed from its frequency noise spectrum and impact of the current driver  

Science Journals Connector (OSTI)

We report on the measurement of the frequency noise properties of a 4.6-?m distributed-feedback quantum-cascade laser (QCL) operating in continuous wave near...?1...is used to convert the frequency fluctuations o...

L. Tombez; S. Schilt; J. Di Francesco; T. Führer; B. Rein; T. Walther…

2012-11-01T23:59:59.000Z

462

Pulsed quantum-cascade-laser spectroscopy with intermediate-size pulses: application to NH3 in the 10 ?m region  

Science Journals Connector (OSTI)

Pulsed quantum-cascade-laser spectrometers are usually used to detect atmospheric...3 spectra recorded at low pressure (i.e. in the mbar range), the spectra show typical oscillations after the absorption. The Bee...

B. Grouiez; V. Zeninari; L. Joly; B. Parvitte

2010-08-01T23:59:59.000Z

463

Laser Action at High k-Space Values in Anti-Correlated Multi-Wavelength Quantum Cascade Lasers  

Science Journals Connector (OSTI)

A two-wavelength Quantum Cascade laser is reported in which one wavelength lases between subband states high in the k-space. Laser action at the two wavelengths is strongly...

Menzel, Stefan; Franz, Kale J; Wasserman, Daniel; Hoffman, Anthony J; Cockburn, John W; Gmachl, Claire F

464

Study of methods for lowering the lasing frequency of a terahertz quantum-cascade laser based on two quantum wells  

Science Journals Connector (OSTI)

Two mechanisms for achieving lower terahertz-range frequencies in quantum-cascade structures with two quantum wells based on GaAs/AlGaAs compounds are ... mechanism is based on the introduction of composite quantum

D. V. Ushakov; Yu. G. Sadofyev; N. Samal

2012-11-01T23:59:59.000Z

465

A coherent quantum cascade laser operating on a combination of even and odd levels of a three-barrier structure  

Science Journals Connector (OSTI)

For the creation of quantum cascade lasers with coherent (collisionless or ballistic) electron ... a level formed from the levels of adjacent quantum wells with different parity of the electron ... increasing the...

É. A. Gel’vich; E. I. Golant; A. B. Pashkovski?

2006-03-01T23:59:59.000Z

466

Latitudinal gradients of coniferous tree species, vegetation, and climate in the Sierran-Cascade axis of Northern California  

Science Journals Connector (OSTI)

Latitudinal gradients of tree species composition along the Sierran/Cascade axis in northern California were explored by comparing forests of Lassen Volcanic and Yosemite National Parks, USA. A calibration pro...

Albert J. Parker

1994-12-01T23:59:59.000Z

467

Fast Hyperspectral Imaging Using a Mid-Infrared Tunable External Cavity Quantum Cascade Laser  

SciTech Connect (OSTI)

An active hyperspectral imaging system using an external cavity quantum cascade laser and a focal plane array acquiring images at 25 Hz from 985 cm-1 to 1075 cm-1 with a resolution of 0.3 cm 1 is demonstrated. The chemical imaging of gases is demonstrated in both static and dynamic cases. The system was also used to analyze liquid and solid samples.

Phillips, Mark C.; Ho, Nicolas

2008-04-23T23:59:59.000Z

468

External Cavity Quantum Cascade Laser for Quartz Tuning Fork Photoacoustic Spectroscopy of Broad Absorption Features  

SciTech Connect (OSTI)

We demonstrate mid-infrared spectroscopy of large molecules with broad absorption features using a tunable external cavity quantum cascade laser. Absorption spectra for two different Freons are measured over the range 1130-1185 cm-1 with 0.2 cm-1 resolution via laser photoacoustic spectroscopy with quartz tuning forks as acoustic transducers. The measured spectra are in excellent agreement with published reference absorption spectra.

Phillips, Mark C.; Myers, Tanya L.; Wojcik, Michael D.; Cannon, Bret D.

2007-05-01T23:59:59.000Z

469

Cascade Problems in Some Atomic Lifetime Measurements at a Heavy-Ion Storage Ring  

SciTech Connect (OSTI)

Lifetimes of 3s{sup 2}3p{sup k} ground configuration levels of Al-, Si-, P-, and S-like ions of Be, Co, and Ni have been measured at a heavy-ion storage ring. Some of the observed decay curves show strong evidence of cascade repopulation from specific 3d levels that feature lifetimes in the same multi-millisecond range as the levels of the ground configuration.

Trabert, E; Hoffmann, J; Krantz, C; Wolf, A; Ishikawa, Y; Santana, J

2008-10-09T23:59:59.000Z

470

Separation of Fine Particles from Gases in Wet Flue Gas Desulfurization System Using a Cascade of Double Towers  

Science Journals Connector (OSTI)

Separation of Fine Particles from Gases in Wet Flue Gas Desulfurization System Using a Cascade of Double Towers ... The authors thank the High-Tech Research and Development Program of China (No. 2008AA05Z306), the Natural Science Foundation of Jiangsu Province (No. BK2008283), and the Scientific Research Foundation of Graduate School of Southeast University for their financial support. ... with high performance by cascading packed columns. ...

Jingjing Bao; Linjun Yang; Shijuan Song; Guilong Xiong

2012-02-15T23:59:59.000Z

471

FERMI @ Elettra -- A Seeded Harmonic Cascade FEL for EUV and SoftX-rays  

SciTech Connect (OSTI)

We describe the machine layout and major performance parameters for the FERMI FEL project funded for construction at Sincrotrone Trieste, Italy, within the next five years. The project will be the first user facility based on seeded harmonic cascade FELs, providing controlled, high peak-power pulses. With a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac, the facility will provide tunable output over a range from {approx}100 nm to {approx}10nm, with pulse duration from 40 fs to {approx} 1 ps, peak power GW, and with fully variable output polarization. Initially, two FEL cascades are planned; a single-stage harmonic generation to operate >40 nm, and a two stage cascade operating from {approx}40 nm to {approx}10 nm or shorter wavelength. The output is spatially and temporally coherent, with peak power in the GW range. Lasers provide modulation to the electron beam, as well as driving the photocathode and other systems, and the facility will integrate laser systems with the accelerator infrastructure, including a state-of-the-art optical timing system providing synchronization of rf signals, lasers, and x-ray pulses. Major systems and overall facility layout are described, and key performance parameters summarized.

Bocchetta, C.; Bulfone, D.; Craievich, P.; Danailov, M.B.; D'Auria,G.; DeNinno, G.; Di Mitri, S.; Diviacco, B.; Ferianis, M.; Gomezel, A.; Iazzourene, F.; Karantzoulis, E.; Parmigiani, F.; Penco, G.; Trovo, M.; Corlett, J.; Fawley, W.; Lidia, S.; Penn, G.; Ratti, A.; Staples, J.; Wilcox, R.; Zholents, A.; Graves, W.; Ilday, F.O.; Kaertner,F.; Wang, D.; Zwart, T.; Cornacchia, M.; Emma, P.; Huang, Z.; Wu, J.

2005-09-01T23:59:59.000Z

472

FERMI@Elettra: A Seeded Harmonic Cascade FEL for EUV and Soft X-Rays  

SciTech Connect (OSTI)

We describe the machine layout and major performance parameters for the FERMI FEL project funded for construction at Sincrotrone Trieste, Italy, within the next five years. The project will be the first user facility based on seeded harmonic cascade FEL's, providing controlled, high peak-power pulses. With a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac, the facility will provide tunable output over a range from {approx}100 nm to {approx}10 nm, with pulse duration from 40 fs to {approx} 1ps, peak power {approx}GW, and with fully variable output polarization. Initially, two FEL cascades are planned; a single-stage harmonic generation to operate > 40 nm, and a two-stage cascade operating from {approx}40 nm to {approx}10 nm or shorter wavelength. The output is spatially and temporally coherent, with peak power in the GW range. Lasers provide modulation to the electron beam, as well as driving the photocathode and other systems, and the facility will integrate laser systems with the accelerator infrastructure, including a state-of-the-art optical timing system providing synchronization of rf signals, lasers, and x-ray pulses. Major systems and overall facility layout are described, and key performance parameters summarized.

Bocchetta, C.J.; Bulfone, D.; Craievich, P.; Danailov, M.B.; D'Auria, G.; De Ninno, G.; Di Mitri, S.; Diviacco, B.; Ferianis, M.; Gomezel, A.; Iazzourene, F.; Karantzoulis, E.; Parmigiani, F.; Penco, G.; Trovo, M.; /Sincrotrone Trieste; Corlett, J.; Fawley, W.; Lidia, S.; Penn, G.; Ratti, A.; Staples, J.; /LBL, Berkeley /MIT /SLAC

2005-12-14T23:59:59.000Z

473

Boosting searches for natural supersymmetry with R-parity violation via gluino cascades  

Science Journals Connector (OSTI)

In the presence of even minuscule baryonic R-parity violation (RPV), the stop can be the lightest superpartner and evade LHC searches because it decays into two jets. In order to cover this interesting possibility, we here consider new searches for RPV stops produced in gluino cascades. While typical searches for gluinos decaying to stops rely on same-sign dileptons, the RPV cascades usually have fewer hard leptons, less excess missing energy, and more jets than R-parity conserving cascades. If the gluino is a Dirac fermion, same-sign dilepton signals are also often highly depleted. We therefore explore search strategies that use single-lepton channels, and combat backgrounds using HT, jet counting, and more detailed multijet kinematics or jet substructure. We demonstrate that the stop mass peaks can be fully reconstructed over a broad range of spectra, even given the very high jet multiplicities. This would not only serve as a “double-discovery” opportunity, but would also be a spectacular confirmation that the elusive top partner has been hiding in multijets.

Zhenyu Han; Andrey Katz; Minho Son; Brock Tweedie

2013-04-02T23:59:59.000Z

474

Granular fountains: Convection cascade in a compartmentalized granular gas  

Science Journals Connector (OSTI)

This paper extends the two-compartment granular fountain [D. van der Meer, P. Reimann, K. van der Weele, and D. Lohse, Phys. Rev. Lett. 92, 184301 (2004)] to an arbitrary number of compartments: The tendency of a granular gas to form clusters is exploited to generate spontaneous convective currents, with particles going down in the well-filled compartments and going up in the diluted ones. We focus upon the bifurcation diagram of the general K-compartment system, which is constructed using a dynamical flux model and which proves to agree quantitatively with results from molecular dynamics simulations.

Devaraj van der Meer; Ko van der Weele; Peter Reimann

2006-06-22T23:59:59.000Z

475

Core Measure Results  

Broader source: Energy.gov (indexed) [DOE]

Core Measure Core Measure Results FY 07 Results FY 08 Results FY 09 Results FY 10 Target FY 10 Customer Perspective: Customer Satisfaction: -Timeliness NM 81 NM NM NM -Quality NM 90 NM NM NM Effective Service Partnership: -Extent of Customer Satisfaction with the responsiveness, etc. NM 87 NM NM NM Internal Business Perspective: Acquisition Excellence: -Extent to which internal quality control systems are effective 86 87 84 87 88 Most Effective Use of Contracting Approaches to Maximize Efficiency and Cost Effectiveness: Use of Electronic Commerce: - % of delivery & purchase orders issued electronically as a % of total simplified actions 70 72 89 99 100 - % of new competitive transactions > $100K conducted through EC 70 72 91 100 95 Performance Based Service Contracts: - PBSCs awarded as a % of eligible new

476

The effect of turbulence on the stability of liquid jets and the resulting droplet size distributions. Third quarterly technical report, July 1, 1993--September 30, 1993  

SciTech Connect (OSTI)

Laminar and turbulent columns of liquids issuing from capillary tubes were studied in order to determine the effects of turbulence on the stability of liquid jets and to establish the influence of liquid turbulence on droplet size distributions after breakup. Two capillary tubes were chosen with diameters D{sub 1}=3.0mm and D{sub 2}=1.2mm; jet Reynolds numbers were 1000--30000, and 400--7200. For water injection into stagnant air, stability curve is bounded by a laminar portion, where a jet radius and {delta}{sub o} initial disturbance amplitude, and a fully developed turbulent portion characterized by high initial disturbance amplitude (ln(a/{delta}{sub o,T}) {approximately} 4.85). In the transition region, ln(a/{delta}{sub o}) is not single valued; it decreases with increasing Reynolds number. In absence of aerodynamic effects, turbulent jets are as stable as laminar jets. For this breakup mode turbulence propagates initial disturbances with amplitudes orders of magnitude larger than laminar jets ({delta}{sub o,T}=28{times}10{sup 6} {delta}{sub o,L}). Growth rates of initial disturbances are same for both laminar and turbulent columns with theoretical Weber values. Droplet size distribution is bi-modal; the number ratio of large (> D/2), to small (< D/2) droplets is 3 and independent of Reynolds number. For laminar flow optimum wavelength ({lambda}{sub opt}) corresponding to fastest growing disturbance is equal to 4.45D, exactly the theoretical Weber value. For turbulent flow conditions, the turbulent column segments. Typically, segments with lengths of one to several wavelengths, detach from the liquid jet. The long ligaments contract under the action of surface tension, resulting in droplet sizes larger than predicted by Rayleigh and Weber. For turbulent flow conditions, {lambda}{sub opt} = 9.2D, about 2 times the optimum Weber wavelength.

Mansour, A.; Chigier, N.

1993-12-01T23:59:59.000Z

477

Silver Clear Nylon Dressing is Effective in Preventing Radiation-Induced Dermatitis in Patients With Lower Gastrointestinal Cancer: Results From a Phase III Study  

SciTech Connect (OSTI)

Purpose: For patients with anal canal and advanced rectal cancer, chemoradiation therapy is a curative modality or an important adjunct to surgery. Nearly all patients treated with chemoradiation experience some degree of radiation-induced dermatitis (RID). Prevention and effective treatment of RID, therefore, is of considerable clinical relevance. The present phase III randomized trial compared the efficacy of silver clear nylon dressing (SCND) with that of standard skin care for these patients. Methods and Materials: A total of 42 rectal or anal canal cancer patients were randomized to either a SCND or standard skin care group. SCND was applied from Day 1 of radiation therapy (RT) until 2 weeks after treatment completion. In the control arm, sulfadiazine cream was applied at the time of skin dermatitis. Printed digital photographs taken 2 weeks prior to, on the last day, and two weeks after the treatment completion were scored by 10 blinded readers, who used the common toxicity scoring system for skin dermatitis. Results: The radiation dose ranged from 50.4 to 59.4 Gy, and there were no differences between the 2 groups. On the last day of RT, when the most severe RID occurs, the mean dermatitis score was 2.53 (standard deviation [SD], 1.17) for the standard and 1.67 (SD, 1.2; P=.01) for the SCND arm. At 2 weeks after RT, the difference was 0.39 points in favor of SCND (P=.39). There was considerable intraclass correlation among the 10 observers. Conclusions: Silver clear nylon dressing is effective in reducing RID in patients with lower gastrointestinal cancer treated with combined chemotherapy and radiation treatment.

Niazi, Tamim M. [Segal Cancer Centre, Department of Radiation Oncology, Jewish General Hospital, McGill University (Canada)] [Segal Cancer Centre, Department of Radiation Oncology, Jewish General Hospital, McGill University (Canada); Vuong, Te, E-mail: tvuong@jgh.mcgill.ca [Segal Cancer Centre, Department of Radiation Oncology, Jewish General Hospital, McGill University (Canada)] [Segal Cancer Centre, Department of Radiation Oncology, Jewish General Hospital, McGill University (Canada); Azoulay, Laurant [Department of Epidemiology, Jewish General Hospital, McGill University (Canada)] [Department of Epidemiology, Jewish General Hospital, McGill University (Canada); Marijnen, Corrie [Department of Clinical Oncology, Leiden University Medical Center, Amsterdam (Netherlands)] [Department of Clinical Oncology, Leiden University Medical Center, Amsterdam (Netherlands); Bujko, Kryzstof [Department of Radiotherapy, The Maria Sklodowska-Curie Memorial Cancer Centre, Warsaw (Poland)] [Department of Radiotherapy, The Maria Sklodowska-Curie Memorial Cancer Centre, Warsaw (Poland); Nasr, Elie [Department of Radiation Oncology, Hotel-Dieu de France Hospital (Lebanon)] [Department of Radiation Oncology, Hotel-Dieu de France Hospital (Lebanon); Lambert, Christine; Duclos, Marie; Faria, Sergio; David, Marc [Department of Radiation Oncology, Montreal-General-Hospital, McGill University, Montreal (Canada)] [Department of Radiation Oncology, Montreal-General-Hospital, McGill University, Montreal (Canada); Cummings, Bernard [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto (Canada)] [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto (Canada)

2012-11-01T23:59:59.000Z

478

Three mirror off axis integrated cavity output spectroscopy for the detection of ethylene using a quantum cascade laser  

Science Journals Connector (OSTI)

Abstract We demonstrate the performance of a compact and robust gas sensor based on a pulsed distributed feedback quantum cascade laser (QCL, laser pulses 30 ns, repetition rate 1 MHz) in combination with off-axis integrated cavity output spectroscopy (OA-ICOS) in an improved 3 mirror configuration. The room temperature laser (wavelength 915 cm?1) was wavelength tuned over ?0.25 cm?1 with a 4 kHz repetition frequency. A detection limit of 10 ppbv (part-per-billion volume) for regular OA-ICOS is demonstrated for ethylene in 2 min averaging time, which is equal to a noise equivalent absorption sensitivity (NEAS) of 1 × 10?8 cm?1 Hz?1/2. An improved three mirror configuration OA-ICOS scheme showed a four times increase in sensitivity as compared to standard OA-ICOS, resulting in a NEAS of 2.5 × 10?9 cm?1 Hz?1/2. The sensor was used for ethylene detection from apples, stored under controlled atmosphere conditions.

R. Centeno; J. Mandon; S.M. Cristescu; F.J.M. Harren

2014-01-01T23:59:59.000Z

479

Parton cascade description of relativistic heavy ion collisions at the CERN Super Proton Synchrotron at 158A GeV?  

SciTech Connect (OSTI)

We examine Pb+Pb collisions at CERN SPS energy 158A GeV by employing the earlier developed and recently refined parton-cascade/cluster-hadronization model and its Monte Carlo implementation. This space-time model involves the dynamical interplay of perturbative QCD parton production and evolution, with nonperturbative parton-cluster formation and hadron production through cluster decays. Using computer simulations, we are able to follow the entwined time evolution of parton and hadron degrees of freedom in both position and momentum space, from the instant of nuclear overlap to the final yield of particles. We present and discuss results for the multiplicity distributions, which agree well with the measured data from the CERN SPS, including those for K mesons. The transverse momentum distributions of the produced hadrons are also found to be in good agreement with the preliminary data measured by the NA49 and WA98 Collaborations for the collision of lead nuclei at the CERN SPS. The analysis of the time evolution of transverse energy deposited in the collision zone and the energy density suggests the existence of partonic matter for a time of more than 5 fm. {copyright} {ital 1997} {ital The American Physical Society}

Geiger, Klaus [Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)] Kumar Srivastava, Dinesh [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Calcutta 700 064 (India)

1997-11-01T23:59:59.000Z

480

Influence of confined phonon modes on the thermal behavior of AlAs/GaAs quantum cascade structures  

Science Journals Connector (OSTI)

The thermal behavior of AlAs/GaAs quantum cascade structures is used to demonstrate the existence of confined and interface optical-phonon modes. The high conduction-band offset of this material system greatly improves the confinement of the electronic states and allows the realization of electroluminescence structures, where the optical power as a function of the temperature solely depends on the change of the upper-state lifetime induced by the longitudinal-optical-phonon population. We observed that the latter is proportional to the Bose-Einstein factor, with an appropriate phonon mode energy, which does not simply correspond to that of the GaAs bulk phonon (36-meV energy). In particular we show that the agreement between theory and experiment can be substantially improved when the confined and interface modes are taken into account in our calculation. Our results are corroborated by the threshold temperature dependence of lasers, with an active region based on similar structures.

C. Becker; C. Sirtori; H. Page; A. Robertson; V. Ortiz; X. Marcadet

2002-01-30T23:59:59.000Z

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481

Fire and the persistence and decline of montane chaparral in mixed conifer forests in the southern Cascades, Lassen Volcanic National Park, CA.  

E-Print Network [OSTI]

??Stands of montane chaparral are an integral component of the mixed conifer forest in the Cascade Mountains of northern California. In this region, chaparral stands… (more)

Airey, Catherine

2012-01-01T23:59:59.000Z

482

A quantum cascade laser-based optical feedback cavity-enhanced absorption spectrometer for the simultaneous measurement of CH4 and N2O in air  

Science Journals Connector (OSTI)

Optical feedback cavity-enhanced absorption spectroscopy (OF CEAS) has been demonstrated with a thermoelectrically cooled continuous wave distributed feedback quantum cascade laser (QCL) operating at wavelengths ...

D. J. Hamilton; A. J. Orr-Ewing

2011-03-01T23:59:59.000Z

483

DOE Average Results  

Broader source: Energy.gov (indexed) [DOE]

DOE DOE Average Results FY 12 DOE Target FY 12 Customer Perspective: Customer Satisfaction: -Timeliness 92 88 -Quality 94 92 Effective Service Partnership: -Extent of Customer Satisfaction with the responsiveness, etc. 90 92 Internal Business Perspective: Acquisition Excellence: -Extent to which internal quality control systems are effective 90 88 Most Effective Use of Contracting Approaches to Maximize Efficiency and Cost Effectiveness: Use of Competition: -% of total $'s obligated on competitive acquisitions >$3000 (Agency Level Only) 94 85 -% of acquisition actions competed for actions > $3000 (Agency Level Only) 65 68 Performance Based Acquisition: - % PBA actions relative to total eligible new acquisition actions (applicable to new actions > $25K) 82

484

Quantum Cascade Laser Spectroscopy and Photoinduced Chemistry of Al–(CO)n Clusters in Helium Nanodroplets  

Science Journals Connector (OSTI)

Quantum Cascade Laser Spectroscopy and Photoinduced Chemistry of Al–(CO)n Clusters in Helium Nanodroplets ... Only aluminum carbonyl clusters of the form Al–(CO)n are observed in this study, and a future report will discuss the larger Alm–(CO)n species. ... The QCL frequency is tuned by rotating a grating with a stepper motor (0.01 cm–1 steps) or by scanning the cavity length continuously (?30 GHz tuning) by applying a 0–100 V sine wave ramp to a piezo element. ...

Tao Liang; Steven D. Flynn; Alexander M. Morrison; Gary E. Douberly

2011-05-26T23:59:59.000Z

485

Detection and measurement of electroreflectance on quantum cascade laser device using Fourier transform infrared microscope  

SciTech Connect (OSTI)

We demonstrate the use of a Fourier Transform Infrared microscope system to detect and measure electroreflectance (ER) from mid-infrared quantum cascade laser (QCL) device. To characterize intersubband transition (ISBT) energies in a functioning QCL device, a microscope is used to focus the probe on the QCL cleaved mirror. The measured ER spectra exhibit resonance features associated to ISBTs under applied electric field in agreement with the numerical calculations and comparable to observed photocurrent, and emission peaks. The method demonstrates the potential as a characterization tool for QCL devices.

Enobio, Eli Christopher I.; Ohtani, Keita; Ohno, Yuzo; Ohno, Hideo, E-mail: ohno@riec.tohoku.ac.jp [Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)] [Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

2013-12-02T23:59:59.000Z

486

Improving proton-induced one-nucleon removal in intranuclear cascade  

E-Print Network [OSTI]

It is a well-established fact that intranuclear-cascade models generally fail to consistently reproduce the cross sections for one-proton and one-neutron removal from stable nuclei by a high-energy proton beam. We use simple shell-model calculations to investigate the reasons of this deficiency. We find that a refined description of the neutron skin and of the energy density in the nuclear surface is crucial for the aforementioned observables, and that neither ingredient is sufficient if taken separately. As a by-product, the predictions for removal of several nucleons are also improved by the refined treatment.

Davide Mancusi; Alain Boudard; Jaume Carbonell; Joseph Cugnon; Jean-Christophe David; Sylvie Leray

2014-11-17T23:59:59.000Z

487

Multi-wavelength surface emitting quantum cascade laser based on equivalent phase shift  

SciTech Connect (OSTI)

A novel surface emitting distributed feedback quantum cascade laser emitting around ????4.6??m is demonstrated by employing an equivalent phase shift (EPS) of quarter-wave (?/4). The EPS is fabricated through extending one sampling period by 50% in the center of a sampled Bragg grating. Single-lobed far-field radiation pattern with a low divergence angle of about 0.6°?×?16.8° is obtained. Selective single-mode lasing with a mean side mode suppression ratio above 20?dB and wavelength coverage range of 72?nm is achieved simultaneously on a single wafer only by changing the sampling period.

Zhang, J. C., E-mail: zhangjinchuan@semi.ac.cn; Liu, F. Q., E-mail: fqliu@semi.ac.cn; Yao, D. Y.; Wang, L. J.; Yan, F. L.; Liu, J. Q.; Wang, Z. G. [Institute of Semiconductors, Key Laboratory of Semiconductor Materials Science, Chinese Academy of Sciences, Beijing, 100083, People’s Republic of China and Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Beijing 100083 (China)

2014-01-21T23:59:59.000Z

488

Standoff reflection–absorption spectra of surface adsorbed explosives measured with pulsed quantum cascade lasers  

Science Journals Connector (OSTI)

Abstract We demonstrate a standoff detection scheme of surface adsorbed explosives based on the broadband quantum cascade laser (QCL) infrared reflection–absorption spectroscopy and ultraviolet laser photodecomposition. We utilized a sub-second rapid-scan data acquisition scheme to record continuously scanned spectra which revealed the broad-band absorption features of surface adsorbed explosive molecules such as cyclotrimethylene trinitramine (RDX) and trinitrotoluene with a surface concentration of 1 ?g/cm2. The standoff QCL spectra perfectly reproduce the reflectance spectra obtained with a conventional Fourier transform infrared spectroscopy instrument. The conformation conversion of RDX molecules is also observed and studied.

Xunchen Liu; Charles W. Van Neste; Manisha Gupta; Ying Y. Tsui; Seonghwan Kim; Thomas Thundat

2014-01-01T23:59:59.000Z

489

An 8-{mu}m quantum cascade laserproduced by the metalorganic vapour phase epitaxy method  

SciTech Connect (OSTI)

An 8-{mu}m quantum cascade laser is fabricated by the metalorganic vapour phase epitaxy method. A scheme of vertical transitions in a structure consisting of three quantum wells is used. The laser operates in a pulsed regime at temperatures up to 250 K. The threshold current density was about 3 kA cm{sup -2} and increased up to 6 kA cm{sup -2} at 250 K. The 1-{mu}s pulse power in the multimode regime was 45 mW at 77 K.

Zasavitskii, I I; Pashkeev, D A [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation); Marmalyuk, Aleksandr A; Ryaboshtan, Yu L [M.F. Stel'makh Polyus Research and Development Institute, Moscow (Russian Federation); Mikaelyan, G T [OJSC Research and Manufacturing Enterprise 'Inject', Saratov (Russian Federation)

2010-02-28T23:59:59.000Z

490

Quantum Cascade Laser Development Efforts for Implementation into Chemical and Remote Sensing Systems  

SciTech Connect (OSTI)

Quantum cascade lasers (QCL) offer many desirable attributes as mid-infrared laser sources for chemical and remote sensing. Some key advantages are a narrow linewidth, wide bandwidth current modulation characteristics and moderate tunability (15 cm-1). Combined, these characteristics allow for applications to a wide variety of chemical and remote sensing techniques such as wavelength and frequency modulation based detection techniques, cavity enhanced point sensors as well as techniques such as LIDAR and DIAL. This paper will describe laser development efforts to enhance QCL frequency stabilization and QCL injection locking and to develop robust external cavity QCL designs.

Wojcik, Michael D.; Myers, Tanya L.; Taubman, Matthew S.; Cannon, Bret D.; Broocks, Bryan T.; Mosely, Trinesha

2004-12-01T23:59:59.000Z

491

Note: Switch-Mode Hybrid Current Controllers for Quantum Cascade Lasers  

SciTech Connect (OSTI)

Chemical sensing in the mid-infrared has been revolutionized by the advent of quantum cascade lasers. Their higher current and voltage demands compared to laser diodes however, negatively impact size, weight and power footprint for fieldable systems, particularly in hot environments. This letter presents a switch-mode/linear hybrid controller design, furnishing low-noise drive current up to 2 amperes at compliance voltages up to 15 volts, with noise levels close to the Johnson noise of the internal resistors. Current modulation from near zero to 1.8 Amps is also demonstrated at frequencies up to a kilohertz.

Taubman, Matthew S.

2013-01-07T23:59:59.000Z

492

Chirped laser dispersion spectroscopy using a directly modulated quantum cascade laser  

SciTech Connect (OSTI)

Chirped laser dispersion spectroscopy (CLaDS) utilizing direct modulation of a quantum cascade laser (QCL) is presented. By controlling the laser bias nearly single- and dual-sideband CLaDS operation can be realized in an extremely simplified optical setup with no external optical modulators. Capability of direct single-sideband modulation is a unique feature of QCLs that exhibit a low linewidth enhancement factor. The developed analytical model shows excellent agreement with the experimental, directly modulated CLaDS spectra. This method overcomes major technical limitations of mid-infrared CLaDS systems by allowing significantly higher modulation frequencies and eliminating optical fringes introduced by external modulators.

Hangauer, Andreas, E-mail: hangauer@princeton.edu; Nikodem, Michal; Wysocki, Gerard, E-mail: gwysocki@princeton.edu [Electrical Engineering Department, Princeton University, Princeton, New Jersey 08544 (United States)] [Electrical Engineering Department, Princeton University, Princeton, New Jersey 08544 (United States); Spinner, Georg [Electrical Engineering Department, Princeton University, Princeton, New Jersey 08544 (United States) [Electrical Engineering Department, Princeton University, Princeton, New Jersey 08544 (United States); Institute for Quantum Electronics, ETH Zurich, 8093 Zurich (Switzerland)

2013-11-04T23:59:59.000Z

493

Room temperature continuous wave operation of quantum cascade lasers with 12.5% wall plug efficiency  

SciTech Connect (OSTI)

An InP based quantum cascade laser heterostructure emitting at 4.6 {mu}m was grown with gas-source molecular beam epitaxy. The wafer was processed into a conventional double-channel ridge waveguide geometry with ridge widths of 19.7 and 10.6 {mu}m without semi-insulating InP regrowth. An uncoated, narrow ridge device with a 4.8 mm cavity length was epilayer down bonded to a diamond submount and exhibits 2.5 W maximum output power with a wall plug efficiency of 12.5% at room temperature in continuous wave operation.

Bai, Y.; Slivken, S.; Darvish, S. R.; Razeghi, M. [Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208 (United States)

2008-07-14T23:59:59.000Z

494

Period doubling cascade in glow discharges: Local versus global differential conductivity  

Science Journals Connector (OSTI)

Short planar glow discharges coupled to a resistive layer exhibit a wealth of spontaneous spatiotemporal patterns. Due to similarities with other pattern forming systems that are described by reaction-diffusion models, several authors have tried to derive such models from discharge physics. We investigate the temporal oscillations of the discharge system and find a cascade of period doubling events. This shows that the inner structure of the discharge is more complex than can be described by a two-component reaction-diffusion-model with negative differential conductivity. We also derive an alternative reduced model.

Danijela D. Šija?i?, Ute Ebert, and Ismail Rafatov

2004-11-23T23:59:59.000Z

495

Bioinspired Approach to Multienzyme Cascade System Construction for Efficient Carbon Dioxide Reduction  

Science Journals Connector (OSTI)

Bioinspired Approach to Multienzyme Cascade System Construction for Efficient Carbon Dioxide Reduction ... In our previous studies, spatially separated enzymatic systems, mimicking natural enzyme organization, were developed by using several kinds of organic–inorganic hybrid microcapsules. ... Briefly, immobilized-enzyme-containing solution (1 mL, 50 mM PBS, pH 7.0) was bubbled with CO2 gas for 0.5 h, and then NADH solution (1 mL, 50 mM PBS, pH 7.0) was added to initiate the reaction. ...

Xiaoli Wang; Zheng Li; Jiafu Shi; Hong Wu; Zhongyi Jiang; Wenyan Zhang; Xiaokai Song; Qinghong Ai

2014-02-12T23:59:59.000Z

496

Infrared near-field spectroscopy of trace explosives using an external cavity quantum cascade laser  

SciTech Connect (OSTI)

Utilizing a broadly-tunable external cavity quantum cascade laser for scattering-type scanning near-field optical microscopy (s-SNOM), we measure infrared spectra of explosives particles by probing characteristic nitro-group resonances in the 7.1-7.9 µm wavelength range. Measurements are presented with spectral resolution of 0.25 cm-1, spatial resolution of 25 nm, <100 attomolar sensitivity, and at a rapid acquisition time of 90 s per spectrum. We demonstrate high reproducibility of the acquired s-SNOM spectra with very high signal-to-noise ratios and relative noise of <0.02 in self-homodyne detection.

Craig, Ian M.; Taubman, Matthew S.; Lea, Alan S.; Phillips, Mark C.; Josberger, Erik E.; Raschke, Markus Bernd

2013-12-16T23:59:59.000Z

497

Hyperspectral Microscopy of Explosives Particles Using an External Cavity Quantum Cascade Laser  

SciTech Connect (OSTI)

Using infrared hyperspectral imaging, we demonstrate microscopy of small particles of the explosives compounds RDX, tetryl, and PETN with near diffraction-limited performance. The custom microscope apparatus includes an external cavity quantum cascade laser illuminator scanned over its tuning range of 9.13-10.53 µm in four seconds, coupled with a microbolometer focal plane array to record infrared transmission images. We use the hyperspectral microscopy technique to study the infrared absorption spectra of individual explosives particles, and demonstrate sub-nanogram detection limits.

Phillips, Mark C.; Bernacki, Bruce E.

2012-12-26T23:59:59.000Z

498

Cascade | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences...

499
500

Cascade Locks  

E-Print Network [OSTI]

trip location DISCLAIMER Neither the State of Washington, nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the State of Washington or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the State of Washington or any agency thereof.

Skamania Lodge; David K. Norman; Jaretta M. Roloff; David K. Norman—assistant State Geologist; David K. Norman; Jaretta M. Roloff