National Library of Energy BETA

Sample records for optimal gap width

  1. Optimal gate-width setting for passive neutrons multiplicity counting

    SciTech Connect (OSTI)

    Croft, Stephen; Evans, Louise G; Schear, Melissa A

    2010-01-01

    When setting up a passive neutron coincidence counter it is natural to ask what coincidence gate settings should be used to optimize the counting precision. If the gate width is too short then signal is lost and the precision is compromised because in a given period only a few coincidence events will be observed. On the other hand if the gate is too large the signal will be maximized but it will also be compromised by the high level of random pile-up or Accidental coincidence events which must be subtracted. In the case of shift register electronics connected to an assay chamber with an exponential dieaway profile operating in the regime where the Accidentals rate dominates the Reals coincidence rate but where dead-time is not a concern, simple arguments allow one to show that the relative precision on the net Reals rate is minimized when the coincidence gate is set to about 1.2 times the lie dieaway time of the system. In this work we show that making the same assumptions it is easy to show that the relative precision on the Triples rates is also at a minimum when the relative precision of the Doubles (or Reals) is at a minimum. Although the analysis is straightforward to our knowledge such a discussion has not been documented in the literature before. Actual measurement systems do not always behave in the ideal we choose to model them. Fortunately however the variation in the relative precision as a function of gate width is rather flat for traditional safeguards counters and so the performance is somewhat forgiving of the exact choice. The derivation further serves to delineate the important parameters which determine the relative counting precision of the Doubles and Triples rates under the regime considered. To illustrate the similarities and differences we consider the relative standard deviation that might be anticipated for a passive correlation count of an axial section of a spent nuclear fuel assembly under practically achievable conditions.

  2. Experimental demonstration of line-width modulation in plasmonic lithography using a solid immersion lens-based active nano-gap control

    SciTech Connect (OSTI)

    Lee, Won-Sup; Kim, Taeseob; Choi, Guk-Jong; Lim, Geon; Joe, Hang-Eun; Gang, Myeong-Gu; Min, Byung-Kwon; Park, No-Cheol; Moon, Hyungbae; Kim, Do-Hyung; Park, Young-Pil

    2015-02-02

    Plasmonic lithography has been used in nanofabrication because of its utility beyond the diffraction limit. The resolution of plasmonic lithography depends on the nano-gap between the nanoaperture and the photoresist surface—changing the gap distance can modulate the line-width of the pattern. In this letter, we demonstrate solid-immersion lens based active non-contact plasmonic lithography, applying a range of gap conditions to modulate the line-width of the pattern. Using a solid-immersion lens-based near-field control system, the nano-gap between the exit surface of the nanoaperture and the media can be actively modulated and maintained to within a few nanometers. The line-widths of the recorded patterns using 15- and 5-nm gaps were 47 and 19.5 nm, respectively, which matched closely the calculated full-width at half-maximum. From these results, we conclude that changing the nano-gap within a solid-immersion lens-based plasmonic head results in varying line-width patterns.

  3. Fiber optic gap gauge

    DOE Patents [OSTI]

    Wood, Billy E.; Groves, Scott E.; Larsen, Greg J.; Sanchez, Roberto J.

    2006-11-14

    A lightweight, small size, high sensitivity gauge for indirectly measuring displacement or absolute gap width by measuring axial strain in an orthogonal direction to the displacement/gap width. The gap gauge includes a preferably titanium base having a central tension bar with springs connecting opposite ends of the tension bar to a pair of end connector bars, and an elongated bow spring connected to the end connector bars with a middle section bowed away from the base to define a gap. The bow spring is capable of producing an axial strain in the base proportional to a displacement of the middle section in a direction orthogonal to the base. And a strain sensor, such as a Fabry-Perot interferometer strain sensor, is connected to measure the axial strain in the base, so that the displacement of the middle section may be indirectly determined from the measurement of the axial strain in the base.

  4. Air Gap Effects in LX-17

    SciTech Connect (OSTI)

    Souers, P C; Ault, S; Avara, R; Bahl, K L; Boat, R; Cunningham, B; Gidding, D; Janzen, J; Kuklo, D; Lee, R; Lauderbach, L; Weingart, W C; Wu, B; Winer, K

    2005-09-26

    Three experiments done over twenty years on gaps in LX-17 are reported. For the detonation front moving parallel to the gaps, jets of gas products were seen coming from the gaps at velocities greater than the detonation velocity. A case can be made that the jet velocity increased with gap thickness but the data is scattered. For the detonation front moving transverse to the gap, time delays were seen. The delays roughly increase with gap width, going from 0-70 ns at 'zero gap' to around 300 ns at 0.5-1 mm gap. Larger gaps of up to 6 mm width almost certainly stopped the detonation, but this was not proved. Real-time resolution of the parallel jets and determination of the actual re-detonation or failure in the transverse case needs to be done in future experiments.

  5. Gap Resolution

    Energy Science and Technology Software Center (OSTI)

    2009-06-16

    With the continued improvements of next generation DNA sequencing technologies and their advantages over traditional Sanger sequencing, the Joint Genome Institute (JGI) has modified its sequencing pipeline to take advantage of the benefits of such technologies. Currently, standard 454 Titanium, paired end 454 Titanium, and Illumina GAll data are generated for all microbial projects and then assembled using draft assemblies at a much greater throughput than before. However, it also presents us with new challenges.more » In addition to the increased throughput, we also have to deal with a larger number of gaps in the Newbler genome assemblies. Gaps in these assemblies are usually caused by repeats (Newbler collapses repeat copies into individual contigs, thus creating gaps), strong secondary structures, and artifacts of the PCR process (specific to 454 paired end libraries). Some gaps in draft assemblies can be resolved merely by adding back the collapsed data from repeats. To expedite gap closure and assembly improvement on large numbers of these assemblies, we developed software to address this issue.« less

  6. Pneumatic gap sensor and method

    DOE Patents [OSTI]

    Bagdal, Karl T.; King, Edward L.; Follstaedt, Donald W.

    1992-01-01

    An apparatus and method for monitoring and maintaining a predetermined width in the gap between a casting nozzle and a casting wheel, wherein the gap is monitored by means of at least one pneumatic gap sensor. The pneumatic gap sensor is mounted on the casting nozzle in proximity to the casting surface and is connected by means of a tube to a regulator and a transducer. The regulator provides a flow of gas through a restictor to the pneumatic gap sensor, and the transducer translates the changes in the gas pressure caused by the proximity of the casting wheel to the pneumatic gap sensor outlet into a signal intelligible to a control device. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. The apparatus and method enables accurate monitoring of the actual casting gap in a simple and reliable manner resistant to the extreme temperatures and otherwise hostile casting environment.

  7. Pneumatic gap sensor and method

    DOE Patents [OSTI]

    Bagdal, K.T.; King, E.L.; Follstaedt, D.W.

    1992-03-03

    An apparatus and method for monitoring and maintaining a predetermined width in the gap between a casting nozzle and a casting wheel, wherein the gap is monitored by means of at least one pneumatic gap sensor. The pneumatic gap sensor is mounted on the casting nozzle in proximity to the casting surface and is connected by means of a tube to a regulator and a transducer. The regulator provides a flow of gas through a restictor to the pneumatic gap sensor, and the transducer translates the changes in the gas pressure caused by the proximity of the casting wheel to the pneumatic gap sensor outlet into a signal intelligible to a control device. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. The apparatus and method enables accurate monitoring of the actual casting gap in a simple and reliable manner resistant to the extreme temperatures and otherwise hostile casting environment. 6 figs.

  8. Calibration curves for some standard Gap Tests

    SciTech Connect (OSTI)

    Bowman, A.L.; Sommer, S.C.

    1989-01-01

    The relative shock sensitivities of explosive compositions are commonly assessed using a family of experiments that can be described by the generic term ''Gap Test.'' Gap tests include a donor charge, a test sample, and a spacer, or gap, between two explosives charges. The donor charge, gap material, and test dimensions are held constant within each different version of the gap test. The thickness of the gap is then varied to find the value at which 50% of the test samples will detonate. The gap tests measure the ease with a high-order detonation can be established in the test explosive, or the ''detonability,'' of the explosive. Test results are best reported in terms of the gap thickness at the 50% point. It is also useful to define the shock pressure transmitted into the test sample at the detonation threshold. This requires calibrating the gap test in terms of shock pressure in the gap as a function of the gap thickness. It also requires a knowledge of the shock Hugoniot of the sample explosive. We used the 2DE reactive hydrodynamic code with Forest Fire burn rates for the donor explosives to calculate calibration curves for several gap tests. The model calculations give pressure and particle velocity on the centerline of the experimental set-up and provide information about the curvature and pulse width of the shock wave. 10 refs., 1 fig.

  9. Gas mixtures for spark gap closing switches

    DOE Patents [OSTI]

    Christophorou, Loucas G.; McCorkle, Dennis L.; Hunter, Scott R.

    1988-01-01

    Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low molecular weight, inert buffer gases. To this can be added a third gas having a low ionization potential relative to the buffer gas. The gas mixtures presented possess properties that optimized the efficiency spark gap closing switches.

  10. Gas mixtures for spark gap closing switches

    DOE Patents [OSTI]

    Christophorou, L.G.; McCorkle, D.L.; Hunter, S.R.

    1987-02-20

    Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low molecular weight, inert buffer gases. To this can be added a third gas having a low ionization potential relative to the buffer gas. The gas mixtures presented possess properties that optimized the efficiency spark gap closing switches. 6 figs.

  11. SU-D-12A-07: Optimization of a Moving Blocker System for Cone-Beam Computed Tomography Scatter Correction

    SciTech Connect (OSTI)

    Ouyang, L; Yan, H; Jia, X; Jiang, S; Wang, J; Zhang, H

    2014-06-01

    Purpose: A moving blocker based strategy has shown promising results for scatter correction in cone-beam computed tomography (CBCT). Different parameters of the system design affect its performance in scatter estimation and image reconstruction accuracy. The goal of this work is to optimize the geometric design of the moving block system. Methods: In the moving blocker system, a blocker consisting of lead strips is inserted between the x-ray source and imaging object and moving back and forth along rotation axis during CBCT acquisition. CT image of an anthropomorphic pelvic phantom was used in the simulation study. Scatter signal was simulated by Monte Carlo calculation with various combinations of the lead strip width and the gap between neighboring lead strips, ranging from 4 mm to 80 mm (projected at the detector plane). Scatter signal in the unblocked region was estimated by cubic B-spline interpolation from the blocked region. Scatter estimation accuracy was quantified as relative root mean squared error by comparing the interpolated scatter to the Monte Carlo simulated scatter. CBCT was reconstructed by total variation minimization from the unblocked region, under various combinations of the lead strip width and gap. Reconstruction accuracy in each condition is quantified by CT number error as comparing to a CBCT reconstructed from unblocked full projection data. Results: Scatter estimation error varied from 0.5% to 2.6% as the lead strip width and the gap varied from 4mm to 80mm. CT number error in the reconstructed CBCT images varied from 12 to 44. Highest reconstruction accuracy is achieved when the blocker lead strip width is 8 mm and the gap is 48 mm. Conclusions: Accurate scatter estimation can be achieved in large range of combinations of lead strip width and gap. However, image reconstruction accuracy is greatly affected by the geometry design of the blocker.

  12. Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive

    DOE Patents [OSTI]

    Konrad, Charles E.; Boothe, Richard W.

    1996-01-01

    A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements.

  13. Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive

    DOE Patents [OSTI]

    Konrad, Charles E.; Boothe, Richard W.

    1994-01-01

    A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements.

  14. Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive

    DOE Patents [OSTI]

    Konrad, C.E.; Boothe, R.W.

    1996-01-23

    A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements. 6 figs.

  15. Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive

    DOE Patents [OSTI]

    Konrad, C.E.; Boothe, R.W.

    1994-02-15

    A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements. 6 figures.

  16. Pulse width modulation inverter with battery charger

    DOE Patents [OSTI]

    Slicker, James M.

    1985-01-01

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

  17. Global synchronization of parallel processors using clock pulse width modulation

    SciTech Connect (OSTI)

    Chen, Dong; Ellavsky, Matthew R.; Franke, Ross L.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Jeanson, Mark J.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Littrell, Daniel; Ohmacht, Martin; Reed, Don D.; Schenck, Brandon E.; Swetz, Richard A.

    2013-04-02

    A circuit generates a global clock signal with a pulse width modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse width modification on the clock signal. The pulse width modification changes a pulse width within a clock period in the clock signal. The clock splitter may distribute the pulse width modified clock signal to a plurality of processors in the parallel computing system.

  18. Molecular resonance phenomena. [Calculation of resonance widths

    SciTech Connect (OSTI)

    Hazi, A.U.

    1980-01-01

    It is attempted to show that the Stieltjes-moment-theory provides a practical and a reasonably accurate method for calculating the widths of molecular resonances. The method seems to possess a number of advantages for molecular applications, since it avoids the explicit construction of continuum wavefunctions. It is very simple to implement the technique numerically, because it requires only existing bound-state electronic structure codes. Through the use of configuration interaction techniques, many-electron correlation and polarization effects can be included in the description of both the resonance and the non-resonant background continuum. To illustrate the utility and the accuracy of the Stieltjes-moment-theory technique, used in conjunction with configuration interaction (CI) wave functions, recent applications to the /sup 1/..sigma../sub u/(1sigma/sub u/ 2sigma/sub g/) autoionizing resonance state of H/sub 2/ and the well known /sup 2/PI/sub g/ state of N/sub 2//sup -/ are discussed. The choices of the one-electron basis sets and the types of many-electron configurations appropriate for these two cases are described. Also, guidelines for the selection of the projection operators defining the resonant and non-resonant subspaces in the case of both Feshbach and shape-resonances are given. The numerical results indicate that the Stieltjes-moment-theory technique, which employs L/sup 2/ basis functions exclusively, produces as accurate resonance parameters as can be extracted from direct electron-molecule scattering calculations, provided approximately the same approximations are used to describe important physical effects such as target polarization. Furthermore the method provides sufficiently accurate fixed-nuclei electronic resonance parameters to be used in ab initio calculation of resonant vibrational excitation cross sections. (WHK)

  19. Bridging Gaps | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Bridging Gaps Bridging Gaps Analysis to identify issues, best practices, and recommendations Implementation of modernization, infrastructure planning, and sustainability efforts ...

  20. A spin-wave logic gate based on a width-modulated dynamic magnonic crystal

    SciTech Connect (OSTI)

    Nikitin, Andrey A.; Ustinov, Alexey B.; Semenov, Alexander A.; Kalinikos, Boris A.; Chumak, Andrii V.; Serga, Alexander A.; Vasyuchka, Vitaliy I.; Hillebrands, Burkard; Lhderanta, Erkki

    2015-03-09

    An electric current controlled spin-wave logic gate based on a width-modulated dynamic magnonic crystal is realized. The device utilizes a spin-wave waveguide fabricated from a single-crystal Yttrium Iron Garnet film and two conducting wires attached to the film surface. Application of electric currents to the wires provides a means for dynamic control of the effective geometry of waveguide and results in a suppression of the magnonic band gap. The performance of the magnonic crystal as an AND logic gate is demonstrated.

  1. EFFECTS OF SEAT WIDTH ON DEVELOPMENT OF ADHESIONS IN STAINLESS...

    Office of Scientific and Technical Information (OSTI)

    STEEL TRIM SPRING OPERATED PRESSURE RELIEF VALVES Citation Details In-Document Search Title: EFFECTS OF SEAT WIDTH ON DEVELOPMENT OF ADHESIONS IN STAINLESS STEEL TRIM ...

  2. Numerical simulations for width fluctuations in compound elastic...

    Office of Scientific and Technical Information (OSTI)

    The statistical theories - the Hauser-Feshbach model with the width fluctuation correction ... in the fast energy region, hence the statistical model codes are essential for the ...

  3. SPARK GAP SWITCH

    DOE Patents [OSTI]

    Neal, R.B.

    1957-12-17

    An improved triggered spark gap switch is described, capable of precisely controllable firing time while switching very large amounts of power. The invention in general comprises three electrodes adjustably spaced and adapted to have a large potential impressed between the outer electrodes. The central electrode includes two separate elements electrically connected togetaer and spaced apart to define a pair of spark gaps between the end electrodes. Means are provided to cause the gas flow in the switch to pass towards the central electrode, through a passage in each separate element, and out an exit disposed between the two separate central electrode elements in order to withdraw ions from the spark gap.

  4. MULTIPLE SPARK GAP SWITCH

    DOE Patents [OSTI]

    Schofield, A.E.

    1958-07-22

    A multiple spark gap switch of unique construction is described which will permit controlled, simultaneous discharge of several capacitors into a load. The switch construction includes a disc electrode with a plurality of protuberances of generally convex shape on one surface. A firing electrode is insulatingly supponted In each of the electrode protuberances and extends substantially to the apex thereof. Individual electrodes are disposed on an insulating plate parallel with the disc electrode to form a number of spark gaps with the protuberances. These electrodes are each connected to a separate charged capacitor and when a voltage ls applied simultaneously between the trigger electrodes and the dlsc electrode, each spark gap fires to connect its capacitor to the disc electrode and a subsequent load.

  5. Precision gap particle separator

    DOE Patents [OSTI]

    Benett, William J.; Miles, Robin; Jones, II., Leslie M.; Stockton, Cheryl

    2004-06-08

    A system for separating particles entrained in a fluid includes a base with a first channel and a second channel. A precision gap connects the first channel and the second channel. The precision gap is of a size that allows small particles to pass from the first channel into the second channel and prevents large particles from the first channel into the second channel. A cover is positioned over the base unit, the first channel, the precision gap, and the second channel. An port directs the fluid containing the entrained particles into the first channel. An output port directs the large particles out of the first channel. A port connected to the second channel directs the small particles out of the second channel.

  6. Optical waveguide device with an adiabatically-varying width

    DOE Patents [OSTI]

    Watts; Michael R. , Nielson; Gregory N.

    2011-05-10

    Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

  7. Multiple gap photovoltaic device

    DOE Patents [OSTI]

    Dalal, Vikram L.

    1981-01-01

    A multiple gap photovoltaic device having a transparent electrical contact adjacent a first cell which in turn is adjacent a second cell on an opaque electrical contact, includes utilizing an amorphous semiconductor as the first cell and a crystalline semiconductor as the second cell.

  8. Capacitor charging FET switcher with controller to adjust pulse width

    DOE Patents [OSTI]

    Mihalka, Alex M.

    1986-01-01

    A switching power supply includes an FET full bridge, a controller to drive the FETs, a programmable controller to dynamically control final output current by adjusting pulse width, and a variety of protective systems, including an overcurrent latch for current control. Power MOSFETS are switched at a variable frequency from 20-50 kHz to charge a capacitor load from 0 to 6 kV. A ferrite transformer steps up the DC input. The transformer primary is a full bridge configuration with the FET switches and the secondary is fed into a high voltage full wave rectifier whose output is connected directly to the energy storage capacitor. The peak current is held constant by varying the pulse width using predetermined timing resistors and counting pulses. The pulse width is increased as the capacitor charges to maintain peak current. A digital ripple counter counts pulses, and after the desired number is reached, an up-counter is clocked. The up-counter output is decoded to choose among different resistors used to discharge a timing capacitor, thereby determining the pulse width. A current latch shuts down the supply on overcurrent due to either excessive pulse width causing transformer saturation or a major bridge fault, i.e., FET or transformer failure, or failure of the drive circuitry.

  9. Width effects in transonic flow over a rectangular cavity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Beresh, Steven J.; Wagner, Justin L.; Henfling, John F.; Spillers, Russell Wayne; Pruett, Brian Owen Matthew

    2015-07-24

    A previous experiment by the present authors studied the flow over a finite-width rectangular cavity at freestream Mach numbers 1.5–2.5. In addition, this investigation considered the influence of three-dimensional geometry that is not replicated by simplified cavities that extend across the entire wind-tunnel test section. The latter configurations have the attraction of easy optical access into the depths of the cavity, but they do not reproduce effects upon the turbulent structures and acoustic modes due to the length-to-width ratio, which is becoming recognized as an important parameter describing the nature of the flow within narrower cavities.

  10. Fjords in viscous fingering: selection of width and opening scale

    SciTech Connect (OSTI)

    Mineev-weinstein, Mark; Ristroph, Leif; Thrasher, Matthew; Swinney, Harry

    2008-01-01

    Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero-surface-tension Laplacian growth equation.) Experiments in rectangular and circular geometries yield fjords with base widths {lambda}{sub c}/2, where {lambda}{sub c} is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0{sup o}{+-}1.0{sup o}. These selection rules hold for a wide range of pumping rates and fjord lengths, widths, and directions.

  11. Aerodynamic drag reduction apparatus for gap-divided bluff bodies such as tractor-trailers

    DOE Patents [OSTI]

    Ortega, Jason M.; Salari, Kambiz

    2006-07-11

    An apparatus for reducing the aerodynamic drag of a bluff-bodied vehicle such as a tractor-trailer in a flowstream, the bluff-bodied vehicle of a type having a leading portion, a trailing portion connected to the leading portion, and a gap between the leading and trailing portions defining a recirculation zone. The apparatus is preferably a baffle assembly, such as a vertical panel, adapted to span a width of the gap between the leading and trailing portions so as to impede cross-flow through the gap, with the span of the baffle assembly automatically adjusting for variations in the gap width when the leading and trailing portions pivot relative to each other.

  12. GAP | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    GAP Environmental Assessment for Gap Material Plutonium - Transport, Receipt, and Processing The U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA), has prepared this Environmental Assessment for Gap Material Plutonium - Transport, Receipt, and Processing to evaluate the potential environmental impacts associated with transporting plutonium from foreign

  13. Improved determination of the width of the top quark

    SciTech Connect (OSTI)

    Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beri S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatia S.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M. -C.; Croc A.; Cutts D.; Das A.; Davies G.; de Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Graf C. P.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; La Cruz I. Heredia-De; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li H.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; et al.

    2012-05-04

    We present an improved determination of the total width of the top quark, {Gamma}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Gamma}{sub t} is extracted from the partial decay width {Gamma}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Gamma}(t {yields} Wb) is obtained from the t-channel single top-quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Gamma}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb}| < 0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.

  14. Mass and Width of the Lowest Resonance in QCD

    SciTech Connect (OSTI)

    Caprini, I.; Colangelo, G.; Leutwyler, H.

    2006-04-07

    We demonstrate that near the threshold, the {pi}{pi} scattering amplitude contains a pole with the quantum numbers of the vacuum- commonly referred to as the {sigma} - and determine its mass and width within small uncertainties. Our derivation does not involve models or parametrizations but relies on a straightforward calculation based on the Roy equation for the isoscalar S wave.

  15. Adaptive step-size algorithm for Fourier beam-propagation method with absorbing boundary layer of auto-determined width

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Learn, R.; Feigenbaum, E.

    2016-05-27

    Two algorithms that enhance the utility of the absorbing boundary layer are presented, mainly in the framework of the Fourier beam-propagation method. One is an automated boundary layer width selector that chooses a near-optimal boundary size based on the initial beam shape. Furthermore, the second algorithm adjusts the propagation step sizes based on the beam shape at the beginning of each step in order to reduce aliasing artifacts.

  16. Coma measurement by use of an alternating phase-shifting mask mark with a specific phase width

    SciTech Connect (OSTI)

    Qiu Zicheng; Wang Xiangzhao; Yuan Qiongyan; Wang Fan

    2009-01-10

    The correlation between the coma sensitivity of the alternating phase-shifting mask (Alt-PSM) mark and the mark's structure is studied based on the Hopkins theory of partially coherent imaging and positive resist optical lithography (PROLITH) simulation. It is found that an optimized Alt-PSM mark with its phase width being two-thirds its pitch has a higher sensitivity to coma than Alt-PSM marks with the same pitch and the different phase widths. The pitch of the Alt-PSM mark is also optimized by PROLITH simulation, and the structure of p=1.92{lambda}/NA and pw=2p/3 proves to be with the highest sensitivity. The optimized Alt-PSM mark is used as a measurement mark to retrieve coma aberration from the projection optics in lithographic tools. In comparison with an ordinary Alt-PSM mark with its phase width being a half its pitch, the measurement accuracies of Z7 and Z14 apparently increase.

  17. Optimizing Performance

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

    Optimizing Performance Optimizing Performance Storage Optimization Optimizing the sizes of the files you store in HPSS and minimizing the number of tapes they are on will lead to...

  18. Gap and stripline combined monitor

    DOE Patents [OSTI]

    Yin, Y.

    1986-08-19

    A combined gap and stripline monitor device for measuring the intensity and position of a charged particle beam bunch in a beam pipe of a synchrotron radiation facility is disclosed. The monitor has first and second beam pipe portions with an axial gap therebetween. An outer pipe cooperates with the first beam pipe portion to form a gap enclosure, while inner strips cooperate with the first beam pipe portion to form a stripline monitor, with the stripline length being the same as the gap enclosure length. 4 figs.

  19. Axial gap rotating electrical machine

    DOE Patents [OSTI]

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  20. Gap and stripline combined monitor

    DOE Patents [OSTI]

    Yin, Y.

    1984-02-16

    A combined gap and stripline monitor device for measuring the intensity and position of a charged particle beam bunch in a beam pipe of a synchrotron radiation facility. The monitor has first and second beam pipe portions with an axial gap therebetween. An outer pipe cooperates with the first beam pipe portion to form a gap enclosure, while inner strips cooperate with the first beam pipe portion to form a stripline monitor, with the stripline length being the same as the gap enclosure length.

  1. Gap and stripline combined monitor

    DOE Patents [OSTI]

    Yin, Yan

    1986-01-01

    A combined gap and stripline monitor device (10) for measuring the intensity and position of a charged particle beam bunch in a beam pipe of a synchotron radiation facility. The monitor has first and second beam pipe portions (11a, 11b) with an axial gap (12) therebetween. An outer pipe (14) cooperates with the first beam pipe portion (11a) to form a gap enclosure, while inner strips (23a-d) cooperate with the first beam pipe portion (11a) to form a stripline monitor, with the stripline length being the same as the gap enclosure length.

  2. FAQS Gap Analysis Qualification Card - Occupational Safety |...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Occupational Safety FAQS Gap Analysis Qualification Card - Occupational Safety Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences ...

  3. FAQS Gap Analysis Qualification Card - Chemical Processing |...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Chemical Processing FAQS Gap Analysis Qualification Card - Chemical Processing Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences ...

  4. Axial couplings and strong decay widths of heavy hadrons

    SciTech Connect (OSTI)

    William Detmold, C.-J. David Lin, Stefan Meinel

    2012-04-01

    We calculate the axial couplings of mesons and baryons containing a heavy quark in the static limit using lattice QCD. These couplings determine the leading interactions in heavy hadron chiral perturbation theory and are central quantities in heavy quark physics, as they control strong decay widths and the light-quark mass dependence of heavy hadron observables. Our analysis makes use of lattice data at six different pion masses, 227 MeV < m{sub {pi}} < 352 MeV, two lattice spacings, a = 0.085, 0.112 fm, and a volume of (2.7 fm){sup 3}. Our results for the axial couplings are g{sub 1} = 0.449(51), g{sub 2} = 0.84(20), and g{sub 3} = 0.71(13), where g{sub 1} governs the interaction between heavy-light mesons and pions and g{sub 2,3} are similar couplings between heavy-light baryons and pions. Using our lattice result for g{sub 3}, and constraining 1/m{sub Q} corrections in the strong decay widths with experimental data for {Sigma}{sub c}{sup (*)} decays, we obtain {Gamma}[{Sigma}{sub b}{sup (*)} {yields} {Lambda}{sub b} {pi}{sup {+-}}] = 4.2(1.0), 4.8(1.1), 7.3(1.6), 7.8(1.8) MeV for the {Sigma}{sub b}{sup +}, {Sigma}{sub b}{sup -}, {Sigma}{sub b}{sup *+}, {Sigma}{sub b}{sup *-} initial states, respectively. We also derive upper bounds on the widths of the {Xi}{sub b}{sup prime(*)} baryons.

  5. A variable-width harmonic probe for multifrequency atomic force microscopy

    SciTech Connect (OSTI)

    Cai, Jiandong; Zhang, Li; Xia, Qi E-mail: michael.wang@nus.edu.sg; Luo, Yangjun; Wang, Michael Yu E-mail: michael.wang@nus.edu.sg

    2015-02-16

    In multifrequency atomic force microscopy (AFM) to simultaneously measure topography and material properties of specimens, it is highly desirable that the higher order resonance frequencies of the cantilever probe are assigned to be integer harmonics of the excitation frequency. The harmonic resonances are essential for significant enhancement of the probe's response at the specified harmonic frequencies. In this letter, a structural optimization technique is employed to design cantilever probes so that the ratios between one or more higher order resonance frequencies and the fundamental natural frequency are ensured to be equal to specified integers and, in the meantime, that the fundamental natural frequency is maximized. Width profile of the cantilever probe is the design variable in optimization. Thereafter, the probes were prepared by modifying a commercial probe through the focused ion beam (FIB) milling. The resonance frequencies of the FIB fabricated probes were measured with an AFM. Results of the measurement show that the optimal design of probe is as effective as design prediction.

  6. Width of the Confining String in Yang-Mills Theory

    SciTech Connect (OSTI)

    Gliozzi, F.; Pepe, M.; Wiese, U.-J.

    2010-06-11

    We investigate the transverse fluctuations of the confining string connecting two static quarks in (2+1)D SU(2) Yang-Mills theory using Monte Carlo calculations. The exponentially suppressed signal is extracted from the large noise by a very efficient multilevel algorithm. The resulting width of the string increases logarithmically with the distance between the static quark charges. Corrections at intermediate distances due to universal higher-order terms in the effective string action are calculated analytically. They accurately fit the numerical data.

  7. Surface roughness and interface width scaling of magnetron sputter deposited Ni/Ti multilayers

    SciTech Connect (OSTI)

    Maidul Haque, S.; Biswas, A.; Tokas, R. B.; Bhattacharyya, D.; Sahoo, N. K.; Bhattacharya, Debarati

    2013-09-14

    Using an indigenously built r.f. magnetron sputtering system, several single layer Ti and Ni films have been deposited at varying deposition conditions. All the samples have been characterized by Grazing Incidence X-ray Reflectivity (GIXR) and Atomic Force Microscopy to estimate their thickness, density, and roughness and a power law dependence of the surface roughness on the film thickness has been established. Subsequently, at optimized deposition condition of Ti and Ni, four Ni/Ti multilayers of 11-layer, 21-layer, 31-layer, and 51-layer having different bilayer thickness have been deposited. The multilayer samples have been characterized by GIXR and neutron reflectivity measurements and the experimental data have been fitted assuming an appropriate sample structure. A power law correlation between the interface width and bilayer thickness has been observed for the multilayer samples, which was explained in the light of alternate roughening/smoothening of multilayers and assuming that at the interface the growth restarts every time.

  8. Determination of the width of the top quark

    SciTech Connect (OSTI)

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Abolins, Maris A.; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; Alverson, George O.; Alves, Gilvan Augusto; /Rio de Janeiro, CBPF /Nijmegen U.

    2010-09-01

    We extract the total width of the top quark, {Lambda}{sub t}, from the partial decay width {Lambda}(t {yields} Wb) measured using the t-channel cross section for single top quark production and from the branching fraction B(t {yields} Wb) measured in t{bar t} events using up to 2.3 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The result is {Lambda}{sub t} = 1.99{sub -0.55}{sup +0.69} GeV, which translates to a top-quark lifetime of {tau}{sub t} = (3.3{sub -0.9}{sup +1.3}) x 10{sup -25} s. Assuming a high mass fourth generation b{prime} quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V{sub tb{prime}}| < 0.63 at 95% C.L.

  9. Development of stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Bo; Tong, Xin; Jiang, Chenyang; Brown, Daniel R.; Robertson, Lee

    2015-06-05

    In this study, we developed a stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping. An optimized external cavity equipped with an off-the-shelf volume holographic grating narrowed the spectral line-width of a 100 W high-power diode laser and stabilized the laser spectrum. The laser spectrum showed a high side mode suppression ratio of >30 dB and good long-term stability (center wavelength drifting within ±0.002 nm during 220 h of operation). Finally, our laser is delivered by a multimode fiber with power ~70 W, center wavelength of 794.77 nm, and spectral bandwidth of ~0.12 nm.

  10. Eight electrode optical readout gap

    DOE Patents [OSTI]

    Boettcher, Gordon E.; Crain, Robert W.

    1985-01-01

    A protective device for a plurality of electrical circuits includes a pluity of isolated electrodes forming a gap with a common electrode. An output signal, electrically isolated from the circuits being monitored, is obtained by a photosensor viewing the discharge gap through an optical window. Radioactive stabilization of discharge characteristics is provided for slowly changing voltages and carbon tipped dynamic starters provide desirable discharge characteristics for rapidly varying voltages. A hydrogen permeation barrier is provided on external surfaces of the device.

  11. Eight electrode optical readout gap

    DOE Patents [OSTI]

    Boettcher, G.E.; Crain, R.W.

    1984-01-01

    A protective device for a plurality of electrical circuits includes a plurality of isolated electrodes forming a gap with a common electrode. An output signal, electrically isolated from the circuits being monitored, is obtained by a photosensor viewing the discharge gap through an optical window. Radioactive stabilization of discharge characteristics is provided for slowly changing voltages and carbon tipped dynamic starters provide desirable discharge characteristics for rapidly varying voltages. A hydrogen permeation barrier is provided on external surfaces of the device.

  12. Pneumatic gap sensor and method

    SciTech Connect (OSTI)

    Bagdal, K.T.; King, E.L.; Follstaedt, D.W.

    1992-03-03

    This patent describes in a casting system which including an apparatus for monitoring the gap between a casting nozzle and a casting surface of a substrate during casting of molten material, wherein the molten material is provided through a channel of the casting nozzle for casting onto the casting surface of the substrate for solidification. It comprises: a pneumatic gap mounted at least partially within a cavity in the casting nozzle adjacent the channel and having a sensor face located within the gap between the nozzle and the casting surface of the substrate, means for supply gas under predetermined pressure to the inlet orifice; and means for measuring the pressure of the gas within the sensor chamber during casting procedures, whereby relative changes in the gap can be determined by corresponding changes in the measured pressure. This patent also describes a method for monitoring the gap between a casting nozzle and a casting surface of a substrate for continuous casting of molten material. It comprises: providing a casting nozzle with a channel for directing the flow of molten material, locating the nozzle and the casting surface is proximity with one another and having a predetermined gap there-between, and dressing the sensor face to correspond in conformation to the casting surface and to adjust the predetermined distance as desired; providing a molten material to the nozzle for casting onto and casting surface; supplying gas at a predetermined pressure to the inlet orifice of the sensor during casting procedures.

  13. Distributed seeding for narrow-line width hard x-ray free-electron...

    Office of Scientific and Technical Information (OSTI)

    for narrow-line width hard x-ray free-electron lasers Citation Details In-Document Search Title: Distributed seeding for narrow-line width hard x-ray free-electron lasers We ...

  14. 23 V.S.A. Section 1431 Height and Width Limits | Open Energy...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: 23 V.S.A. Section 1431 Height and Width LimitsLegal Abstract Limits for the height and width...

  15. Hydrothermal Exploration Data Gap Analysis Update

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Hydrothermal Exploration Data Gap Analysis Update GTP Peer Review Lunch Presentation Westminster, CO Kate Young Dan Getman Ariel Esposito May 10, 2012 2 Data Gap Analysis PROJECT ...

  16. Evaluation of partial widths and branching ratios from resonance wave functions

    SciTech Connect (OSTI)

    Goldzak, Tamar; Gilary, Ido; Moiseyev, Nimrod

    2010-11-15

    A quantum system in a given resonance state has different open channels for decay. Partial widths are the decay rates of the resonance (metastable) state into the different open channels. Here we present a rigorous derivation of the partial widths from the solution of a time-dependent Schroedinger equation with outgoing boundary conditions. We show that the sum of the partial widths obtained from the resonance wave function is equal to the total width. The difference with respect to previous studies on partial widths and branching ratios is discussed.

  17. Measurement of effective sheath width around cutoff probe in low-pressure plasmas

    SciTech Connect (OSTI)

    Kim, D. W.; Oh, W. Y.; You, S. J. Kim, J. H.; Chang, H. Y.

    2014-05-15

    Previous studies indicated that the measurement results of microwave probes can be improved by applying the adequate sheath width to their measurement models, and consequently the sheath width around the microwave probe tips has become very important information for microwave probe diagnostics. In this paper, we propose a method for measuring the argon plasma sheath width around the cutoff probe tips by applying the circuit model to the cutoff probe phase spectrum. The measured sheath width of the cutoff probe was found to be in good agreement with the floated sheath width calculated from the Child-Langmuir sheath law. The physical reasons for a discrepancy between the two measurements are also discussed.

  18. ABORT GAP CLEANING IN RHIC.

    SciTech Connect (OSTI)

    DREES,A.; AHRENS,L.; III FLILLER,R.; GASSNER,D.; MCINTYRE,G.T.; MICHNOFF,R.; TRBOJEVIC,D.

    2002-06-03

    During the RHIC Au-run in 2001 the 200 MHz storage cavity system was used for the first time. The rebucketing procedure caused significant beam debunching in addition to amplifying debunching due to other mechanisms. At the end of a four hour store, debunched beam could account for approximately 30%-40% of the total beam intensity. Some of it will be in the abort gap. In order to minimize the risk of magnet quenching due to uncontrolled beam losses at the time of a beam dump, a combination of a fast transverse kicker and copper collimators were used to clean the abort gap. This report gives an overview of the gap cleaning procedure and the achieved performance.

  19. Virtual gap dielectric wall accelerator

    DOE Patents [OSTI]

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  20. Multiple input electrode gap controller

    DOE Patents [OSTI]

    Hysinger, Christopher L.; Beaman, Joseph J.; Melgaard, David K.; Williamson, Rodney L.

    1999-01-01

    A method and apparatus for controlling vacuum arc remelting (VAR) furnaces by estimation of electrode gap based on a plurality of secondary estimates derived from furnace outputs. The estimation is preferably performed by Kalman filter. Adaptive gain techniques may be employed, as well as detection of process anomalies such as glows.

  1. Multiple input electrode gap controller

    DOE Patents [OSTI]

    Hysinger, C.L.; Beaman, J.J.; Melgaard, D.K.; Williamson, R.L.

    1999-07-27

    A method and apparatus for controlling vacuum arc remelting (VAR) furnaces by estimation of electrode gap based on a plurality of secondary estimates derived from furnace outputs. The estimation is preferably performed by Kalman filter. Adaptive gain techniques may be employed, as well as detection of process anomalies such as glows. 17 figs.

  2. Method for selecting minimum width of leaf in multileaf adjustable collimator while inhibiting passage of particle beams of radiation through sawtooth joints between collimator leaves

    DOE Patents [OSTI]

    Ludewigt, Bernhard; Bercovitz, John; Nyman, Mark; Chu, William

    1995-01-01

    A method is disclosed for selecting the minimum width of individual leaves of a multileaf adjustable collimator having sawtooth top and bottom surfaces between adjacent leaves of a first stack of leaves and sawtooth end edges which are capable of intermeshing with the corresponding sawtooth end edges of leaves in a second stack of leaves of the collimator. The minimum width of individual leaves in the collimator, each having a sawtooth configuration in the surface facing another leaf in the same stack and a sawtooth end edge, is selected to comprise the sum of the penetration depth or range of the particular type of radiation comprising the beam in the particular material used for forming the leaf; plus the total path length across all the air gaps in the area of the joint at the edges between two leaves defined between lines drawn across the peaks of adjacent sawtooth edges; plus at least one half of the length or period of a single sawtooth. To accomplish this, in accordance with the method of the invention, the penetration depth of the particular type of radiation in the particular material to be used for the collimator leaf is first measured. Then the distance or gap between adjoining or abutting leaves is selected, and the ratio of this distance to the height of the sawteeth is selected. Finally the number of air gaps through which the radiation will pass between sawteeth is determined by selecting the number of sawteeth to be formed in the joint. The measurement and/or selection of these parameters will permit one to determine the minimum width of the leaf which is required to prevent passage of the beam through the sawtooth joint.

  3. Emplacement Gantry Gap Analysis Study

    SciTech Connect (OSTI)

    R. Thornley

    2005-05-27

    To date, the project has established important to safety (ITS) performance requirements for structures, systems, and components (SSCs) based on the identification and categorization of event sequences that may result in a radiological release. These performance requirements are defined within the ''Nuclear Safety Design Bases for License Application'' (NSDB) (BSC 2005 [DIRS 171512], Table A-11). Further, SSCs credited with performing safety functions are classified as ITS. In turn, assurance that these SSCs will perform as required is sought through the use of consensus codes and standards. This gap analysis is based on the design completed for license application only. Accordingly, identification of ITS SSCs beyond those defined within the NSDB are based on designs that may be subject to further development during detail design. Furthermore, several design alternatives may still be under consideration to satisfy certain safety functions, and final selection will not be determined until further design development has occurred. Therefore, for completeness, alternative designs currently under consideration will be discussed throughout this study. This gap analysis will evaluate each code and standard identified within the ''Emplacement Gantry ITS Standards Identification Study'' (BSC 2005 [DIRS 173586]) to ensure each ITS performance requirement is fully satisfied. When a performance requirement is not fully satisfied, a gap is highlighted. This study will identify requirements to supplement or augment the code or standard to meet performance requirements. Further, this gap analysis will identify nonstandard areas of the design that will be subject to a design development plan. Nonstandard components and nonstandard design configurations are defined as areas of the design that do not follow standard industry practices or codes and standards. Whereby, assurance that an SSC will perform as required may not be readily sought though the use of consensus standards. This

  4. Electronic gap sensor and method

    DOE Patents [OSTI]

    Williams, Robert S.; King, Edward L.; Campbell, Steven L.

    1991-01-01

    An apparatus and method for regulating the gap between a casting nozzle and a casting wheel in which the gap between the casting nozzle and the casting wheel is monitored by means of at least one sensing element protruding from the face of the casting nozzle. The sensing element is preferably connected to a voltage source and the casting wheel grounded. When the sensing element contacts the casting wheel, an electric circuit is completed. The completion of the circuit can be registered by an indicator, and the presence or absence of a completed circuit indicates the relative position of the casting nozzle to the casting wheel. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces.

  5. Electronic gap sensor and method

    DOE Patents [OSTI]

    Williams, R.S.; King, E.L.; Campbell, S.L.

    1991-08-06

    Disclosed are an apparatus and method for regulating the gap between a casting nozzle and a casting wheel in which the gap between the casting nozzle and the casting wheel is monitored by means of at least one sensing element protruding from the face of the casting nozzle. The sensing element is preferably connected to a voltage source and the casting wheel grounded. When the sensing element contacts the casting wheel, an electric circuit is completed. The completion of the circuit can be registered by an indicator, and the presence or absence of a completed circuit indicates the relative position of the casting nozzle to the casting wheel. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. 5 figures.

  6. Sootblowing optimization for improved boiler performance

    DOE Patents [OSTI]

    James, John Robert; McDermott, John; Piche, Stephen; Pickard, Fred; Parikh, Neel J

    2013-07-30

    A sootblowing control system that uses predictive models to bridge the gap between sootblower operation and boiler performance goals. The system uses predictive modeling and heuristics (rules) associated with different zones in a boiler to determine an optimal sequence of sootblower operations and achieve boiler performance targets. The system performs the sootblower optimization while observing any operational constraints placed on the sootblowers.

  7. Sootblowing optimization for improved boiler performance

    DOE Patents [OSTI]

    James, John Robert; McDermott, John; Piche, Stephen; Pickard, Fred; Parikh, Neel J.

    2012-12-25

    A sootblowing control system that uses predictive models to bridge the gap between sootblower operation and boiler performance goals. The system uses predictive modeling and heuristics (rules) associated with different zones in a boiler to determine an optimal sequence of sootblower operations and achieve boiler performance targets. The system performs the sootblower optimization while observing any operational constraints placed on the sootblowers.

  8. Closed Gap Enzen | Open Energy Information

    Open Energy Info (EERE)

    search Name: Closed Gap-Enzen Place: Bangalore, India Zip: 560 052 Product: Formed as a joint venture, Closed Gap-Enzen provides a new integrated meter enabling seamless customer...

  9. CHARACTERIZING DETONATING LX-17 CHARGES CROSSING A TRANSVERSE AIR GAP WITH EXPERIMENTS AND MODELING

    SciTech Connect (OSTI)

    Lauderbach, L M; Souers, P C; Garcia, F; Vitello, P; Vandersall, K S

    2009-06-26

    Experiments were performed using detonating LX-17 (92.5% TATB, 7.5% Kel-F by weight) charges with various width transverse air gaps with manganin peizoresistive in-situ gauges present. The experiments, performed with 25 mm diameter by 25 mm long LX-17 pellets with the transverse air gap in between, showed that transverse gaps up to about 3 mm could be present without causing the detonation wave to fail to continue as a detonation. The Tarantula/JWL{sup ++} code was utilized to model the results and compare with the in-situ gauge records with some agreement to the experimental data with additional work needed for a better match to the data. This work will present the experimental details as well as comparison to the model results.

  10. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, Gerald J.; Roose, Lars D.

    1996-01-01

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed.

  11. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, G.J.; Roose, L.D.

    1996-04-23

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed. 13 figs.

  12. Colorado - C.R.S. 42-4-502, Width of Load | Open Energy Information

    Open Energy Info (EERE)

    Colorado - C.R.S. 42-4-502, Width of Load Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: Colorado - C.R.S. 42-4-502, Width of...

  13. Hyperparameter Optimization

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

    Optimization Hyperparameter Optimization In machine learning, parameters are the values that describe a machine learning model and are usually chosen by a learning algorithm. Hyperparameters, on the other hand, are parameters for the learning algorithm. The process of looking for the most optimal hyperparameters for a machine learning algorithm is called hyperparameter optimization. We support a few pieces of software for hyperparameter optimzation. Single Node Scikit-Learn Grid Search Random

  14. Photonic band gap structure simulator

    DOE Patents [OSTI]

    Chen, Chiping; Shapiro, Michael A.; Smirnova, Evgenya I.; Temkin, Richard J.; Sirigiri, Jagadishwar R.

    2006-10-03

    A system and method for designing photonic band gap structures. The system and method provide a user with the capability to produce a model of a two-dimensional array of conductors corresponding to a unit cell. The model involves a linear equation. Boundary conditions representative of conditions at the boundary of the unit cell are applied to a solution of the Helmholtz equation defined for the unit cell. The linear equation can be approximated by a Hermitian matrix. An eigenvalue of the Helmholtz equation is calculated. One computation approach involves calculating finite differences. The model can include a symmetry element, such as a center of inversion, a rotation axis, and a mirror plane. A graphical user interface is provided for the user's convenience. A display is provided to display to a user the calculated eigenvalue, corresponding to a photonic energy level in the Brilloin zone of the unit cell.

  15. Controlling the width of a femtosecond continuum generated in a small-diameter fibre

    SciTech Connect (OSTI)

    Kobtsev, Sergey M; Kukarin, S V; Fateev, N V

    2002-01-31

    The control of the width of a continuum generated in a tapered germanium-doped silica fibre with the waist diameter of {approx}3 {mu}m is experimentally demonstrated for the first time. The width of the continuum was controlled by varying the wavelength of chirped femtosecond pump pulses near the zero-point of the group velocity dispersion of the fibre. The width of the continuum at the -20-dB level was varied from 98 to 790 nm by tuning the central wavelength of 80-fs, 0.6-nJ input pulses from 789 to 847 nm. (control of laser radiation parameters)

  16. Spatial variation of dosimetric leaf gap and its impact on dose delivery

    SciTech Connect (OSTI)

    Kumaraswamy, Lalith K.; Schmitt, Jonathan D.; Bailey, Daniel W.; Xu, Zheng Zheng; Podgorsak, Matthew B.

    2014-11-01

    Purpose: During dose calculation, the Eclipse treatment planning system (TPS) retracts the multileaf collimator (MLC) leaf positions by half of the dosimetric leaf gap (DLG) value (measured at central axis) for all leaf positions in a dynamic MLC plan to accurately model the rounded leaf ends. The aim of this study is to map the variation of DLG along the travel path of each MLC leaf pair and quantify how this variation impacts delivered dose. Methods: 6 MV DLG values were measured for all MLC leaf pairs in increments of 1.0 cm (from the line intersecting the CAX and perpendicular to MLC motion) to 13.0 cm off axis distance at dmax. The measurements were performed on two Varian linear accelerators, both employing the Millennium 120-leaf MLCs. The measurements were performed at several locations in the beam with both a Sun Nuclear MapCHECK device and a PTW pinpoint ion chamber. Results: The measured DLGs for the middle 40 MLC leaf pairs (each 0.5 cm width) at positions along a line through the CAX and perpendicular to MLC leaf travel direction were very similar, varying maximally by only 0.2 mm. The outer 20 MLC leaf pairs (each 1.0 cm width) have much lower DLG values, about 0.30.5 mm lower than the central MLC leaf pair, at their respective central line position. Overall, the mean and the maximum variation between the 0.5 cm width leaves and the 1.0 cm width leaf pairs are 0.32 and 0.65 mm, respectively. Conclusions: The spatial variation in DLG is caused by the variation of intraleaf transmission through MLC leaves. Fluences centered on the CAX would not be affected since DLG does not vary; but any fluences residing significantly off axis with narrow sweeping leaves may exhibit significant dose differences. This is due to the fact that there are differences in DLG between the true DLG exhibited by the 1.0 cm width outer leaves and the constant DLG value utilized by the TPS for dose calculation. Since there are large differences in DLG between the 0.5 cm width

  17. Scaling trends in SET pulse widths in Sub-100 nm bulk CMOS processes.

    SciTech Connect (OSTI)

    Narasimham, Balaji; Ahlbin, Jonathan R.; Schrimpf, Ronald D.; Gadlage, Matthew J.; Massengill, Lloyd W.; Vizkelethy, Gyorgy; Reed, Robert A.; Bhuva, Bharat L.

    2010-07-01

    Digital single-event transient (SET) measurements in a bulk 65-nm process are compared to transients measured in 130-nm and 90-nm processes. The measured SET widths are shorter in a 65-nm test circuit than SETs measured in similar 90-nm and 130-nm circuits, but, when the factors affecting the SET width measurements (in particular pulse broadening and the parasitic bipolar effect) are considered, the actual SET width trends are found to be more complex. The differences in the SET widths between test circuits can be attributed in part to differences in n-well contact area. These results help explain some of the inconsistencies in SET measurements presented by various researchers over the past few years.

  18. Differential two-body compound nuclear cross section, including the width-fluctuation corrections

    SciTech Connect (OSTI)

    Brown, D.; Herman, M.

    2014-09-02

    We figure out the compound angular differential cross sections, following mainly Fröbrich and Lipperheide, but with the angular momentum couplings that make sense for optical model work. We include the width-fluctuation correction along with calculations.

  19. Bounding the Higgs Width Through Interferometry (Journal Article) | SciTech

    Office of Scientific and Technical Information (OSTI)

    Connect Journal Article: Bounding the Higgs Width Through Interferometry Citation Details In-Document Search Title: Bounding the Higgs Width Through Interferometry Authors: Dixon, Lance J. ; Li, Ye ; /SLAC Publication Date: 2013-05-24 OSTI Identifier: 1080221 Report Number(s): SLAC-PUB-15463 arXiv:1305.3854 DOE Contract Number: AC02-76SF00515 Resource Type: Journal Article Resource Relation: Journal Name: Submitted to Physical Review Letters Research Org: SLAC National Accelerator Laboratory

  20. Gap Assessment (FY 13 Update)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Getman, Dan

    2013-09-30

    To help guide its future data collection efforts, The DOE GTO funded a data gap analysis in FY2012 to identify high potential hydrothermal areas where critical data are needed. This analysis was updated in FY2013 and the resulting datasets are represented by this metadata. The original process was published in FY 2012 and is available here: https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2013/Esposito.pdf Though there are many types of data that can be used for hydrothermal exploration, five types of exploration data were targeted for this analysis. These data types were selected for their regional reconnaissance potential, and include many of the primary exploration techniques currently used by the geothermal industry. The data types include: 1. well data 2. geologic maps 3. fault maps 4. geochemistry data 5. geophysical data To determine data coverage, metadata for exploration data (including data type, data status, and coverage information) were collected and catalogued from nodes on the National Geothermal Data System (NGDS). It is the intention of this analysis that the data be updated from this source in a semi-automated fashion as new datasets are added to the NGDS nodes. In addition to this upload, an online tool was developed to allow all geothermal data providers to access this assessment and to directly add metadata themselves and view the results of the analysis via maps of data coverage in Geothermal Prospector (http://maps.nrel.gov/gt_prospector). A grid of the contiguous U.S. was created with 88,000 10-km by 10-km grid cells, and each cell was populated with the status of data availability corresponding to the five data types. Using these five data coverage maps and the USGS Resource Potential Map, sites were identified for future data collection efforts. These sites signify both that the USGS has indicated high favorability of occurrence of geothermal resources and that data gaps exist. The uploaded data are contained in two data files for

  1. Gap between active and passive solar heating

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1985-01-01

    The gap between active and passive solar could hardly be wider. The reasons for this are discussed and advantages to narrowing the gap are analyzed. Ten years of experience in both active and passive systems are reviewed, including costs, frequent problems, performance prediction, performance modeling, monitoring, and cooling concerns. Trends are analyzed, both for solar space heating and for service water heating. A tendency for the active and passive technologies to be converging is observed. Several recommendations for narrowing the gap are presented.

  2. Hydrothermal Exploration Data Gap Analysis Update

    Broader source: Energy.gov [DOE]

    Hydrothermal Exploration Data Gap Analysis presentation by Kate Young, Dan Getman, and Ariel Esposito at the 2012 Peer Review Meeting on May 10, 2012

  3. FAQS Gap Analysis Qualification Card Emergency Management

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  4. Optimizing Performance

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

    Optimizing Performance Optimizing Performance Storage Optimization Optimizing the sizes of the files you store in HPSS and minimizing the number of tapes they are on will lead to the most effient use of NERSC HPSS: File sizes of about 1 GB or larger will give the best network performance (see graph below) Files sizes greater than about 500 GB can be more difficult to work with and lead to longer transfer times. Files larger than 15 TB cannot be uploaded to HPSS. Aggregate groups of small files

  5. Debt Optimization

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

    IPR 2008 Capital Investment Review CIR 2012 Quarterly Business Review Focus 2028 2011 Strategic Capital Discussions Access to Capital Debt Optimization Asset Management Cost...

  6. Effect of gaps on the performance of the vertically installed wet thermal insulator

    SciTech Connect (OSTI)

    Kim, S. H.; Kim, Y. I.; Park, C. T.; Choi, S.; Yoon, J.

    2012-07-01

    In SMART, the main flow path of the reactor coolant and the pressurizer partially share common walls in the reactor coolant system. To reduce this heat transfer, the wet thermal insulator (WTI) is installed on the inner wall of the pressurizer. The WTI is constituted of stacked thin stainless steel plates. The water layer width between the plates is chosen to suppress natural convection in each layer. The plates of the WTI require clearance for thermal expansion. When the WTI is installed on a vertical wall, this clearance might cause gaps at the top and bottom at the operating condition. In this study, we focused on the effect of gaps at the both ends on the WTI performance. A numerical simulation was conducted for an 8-layer WTI with gaps at the both ends. To compare with this, a simulation of a WTI without a gap, which is an ideal case, was also conducted. The simulation was conducted in a 2-dimensional manner by a commercial computational fluid dynamics code, FLUENT. The simulations showed that the WTI thermal performance was substantially decreased by a flow that circulated through the top and bottom gaps and water layers at the sides of the WTI. This circulation caused a high temperature difference between the wall and the circulating flow. To find a way to prevent this performance deterioration of the WTI we simulated several cases with the smaller gap heights. However, the flow circulation and the higher heat transfer rate were still observed even at a case with the smallest gap, which seems to be hardly achievable in a real installation. Another way of reducing the flow circulation was suggested and also simulated in this study. (authors)

  7. Solar wind suprathermal electron Stahl widths across high-speed stream structures

    SciTech Connect (OSTI)

    Skoug, Ruth M [Los Alamos National Laboratory; Steinberg, John T [Los Alamos National Laboratory; Goodrich, Katherine A [Los Alamos National Laboratory; Anderson, Brett R [DARTMUTH UNIV.

    2011-01-03

    Suprathermal electrons (100-1500 eV) observed in the solar wind typically show a strahl distribution, that is, a beam directed away from the Sun along the magnetic field direction. The strahl width observed at 1 AU is highly variable, ranging from 10-70 degrees. The obsenred finite width of the strahl results from the competition between beam focusing as the interplanetary magnetic field strength drops with distance from the Sun, and pitch-angle scattering as the beam interacts with the solar wind plasma in transit from the sun. Here we examine strahl width, observed with ACE SWEPAM across high-speed stream structures to investigate variations in electron scattering as a function of local plasma characteristics. We find that narrow strahls (less than 20 degrees wide), indicating reduced scattering, are observed within high-speed streams. Narrow strahls are also observed in both very low temperature solar wind, in association with ICMEs. Case studies of high-speed streams typically show the strahl narrowing at the leading edge of the stream. In some cases, the strahl narrows at the reverse shock or pressure wave, in other cases at the stream interface. The narrowing can either occur discontinuously or gradually over a period of hours. Within the high-speed wind, the strahl remains narrow for a period of hours to days, and then gradually broadens. The strahl width is roughly constant at all energies across these structures. For some fraction of high-speed streams, counterstreaming is associated with passage of the corotating interaction region. In these cases, we find the widths of the two counterstreaming beams frequently differ by more than 40 degrees. This dramatic difference in strahl width contrasts with observations in the solar wind as a whole, in which counterstreaming strahls typically differ in width by less than 20 degrees.

  8. Drop short control of electrode gap

    DOE Patents [OSTI]

    Fisher, Robert W.; Maroone, James P.; Tipping, Donald W.; Zanner, Frank J.

    1986-01-01

    During vacuum consumable arc remelting the electrode gap between a consumable electrode and a pool of molten metal is difficult to control. The present invention monitors drop shorts by detecting a decrease in the voltage between the consumable electrode and molten pool. The drop shorts and their associated voltage reductions occur as repetitive pulses which are closely correlated to the electrode gap. Thus, the method and apparatus of the present invention controls electrode gap based upon drop shorts detected from the monitored anode-cathode voltage. The number of drop shorts are accumulated, and each time the number of drop shorts reach a predetermined number, the average period between drop shorts is calculated from this predetermined number and the time in which this number is accumulated. This average drop short period is used in a drop short period electrode gap model which determines the actual electrode gap from the drop short. The actual electrode gap is then compared with a desired electrode gap which is selected to produce optimum operating conditions and the velocity of the consumable error is varied based upon the gap error. The consumable electrode is driven according to any prior art system at this velocity. In the preferred embodiment, a microprocessor system is utilized to perform the necessary calculations and further to monitor the duration of each drop short. If any drop short exceeds a preset duration period, the consumable electrode is rapidly retracted a predetermined distance to prevent bonding of the consumable electrode to the molten remelt.

  9. Narrow band gap amorphous silicon semiconductors

    DOE Patents [OSTI]

    Madan, A.; Mahan, A.H.

    1985-01-10

    Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises the steps of forming an alloy comprising amorphous silicon and at least one of the aforesaid band gap narrowing elements in amount sufficient to narrow the band gap of the silicon semiconductor alloy below that of amorphous silicon, and also utilizing sufficient amounts of the aforesaid electron donor dopant to maintain the amorphous silicon alloy as an n-type semiconductor.

  10. Scaling of the giant dipole resonance widths in hot rotating nuclei from the ground state values

    SciTech Connect (OSTI)

    Bhattacharya, Srijit; Pandit, Deepak; Mukhopadhyay, S.; Pal, Surajit; Banerjee, S. R.

    2008-12-15

    The systematics of the giant dipole resonance (GDR) widths in hot and rotating nuclei are studied in terms of temperature T, angular momentum J, and mass A. The different experimental data in the temperature range of 1-2 MeV have been compared with the thermal shape fluctuation model (TSFM) in the liquid drop formalism using a modified approach to estimate the average values of T, J, and A in the decay of the compound nucleus. The values of the ground state GDR widths have been extracted from the TSFM parametrization in the liquid drop limit for the corrected T, J, and A for a given system and compared with the corresponding available systematics of the experimentally measured ground state GDR widths for a range of nuclei from A=45 to 194. Amazingly, the nature of the theoretically extracted ground state GDR widths matches remarkably well, though 1.5 times smaller, with the experimentally measured ground state GDR widths consistently over a wide range of nuclei.

  11. Precision measurement of the mass and width of the W boson at CDF

    SciTech Connect (OSTI)

    Malik, Sarah Alam

    2009-09-01

    A precision measurement of the mass and width of the W boson is presented. The W bosons are produced in proton antiproton collisions occurring at a centre of mass energy of 1.96 TeV at the Tevatron accelerator. The data used for the analyses is collected by the Collider Detector at Fermilab (CDF) and corresponds to an average integrated luminosity of 350 pb-1 for the W width analysis for the electron and muon channels and an average integrated luminosity of 2350 pb-1 for the W mass analysis. The mass and width of the W boson is extracted by fitting to the transverse mass distribution, with the peak of the distribution being most sensitive to the mass and the tail of the distribution sensitive to the width. The W width measurement in the electron and muon channels is combined to give a final result of 2032 ± 73 MeV. The systematic uncertainty on the W mass from the recoil of the W boson against the initial state gluon radiation is discussed. A systematic study of the recoil in Z → e+e- events where one electron is reconstructed in the central calorimeter and the other in the plug calorimeter and its effect on the W mass is presented for the first time in this thesis.

  12. Efficient Computation of Info-Gap Robustness for Finite Element Models

    SciTech Connect (OSTI)

    Stull, Christopher J.; Hemez, Francois M.; Williams, Brian J.

    2012-07-05

    A recent research effort at LANL proposed info-gap decision theory as a framework by which to measure the predictive maturity of numerical models. Info-gap theory explores the trade-offs between accuracy, that is, the extent to which predictions reproduce the physical measurements, and robustness, that is, the extent to which predictions are insensitive to modeling assumptions. Both accuracy and robustness are necessary to demonstrate predictive maturity. However, conducting an info-gap analysis can present a formidable challenge, from the standpoint of the required computational resources. This is because a robustness function requires the resolution of multiple optimization problems. This report offers an alternative, adjoint methodology to assess the info-gap robustness of Ax = b-like numerical models solved for a solution x. Two situations that can arise in structural analysis and design are briefly described and contextualized within the info-gap decision theory framework. The treatments of the info-gap problems, using the adjoint methodology are outlined in detail, and the latter problem is solved for four separate finite element models. As compared to statistical sampling, the proposed methodology offers highly accurate approximations of info-gap robustness functions for the finite element models considered in the report, at a small fraction of the computational cost. It is noted that this report considers only linear systems; a natural follow-on study would extend the methodologies described herein to include nonlinear systems.

  13. Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap

    SciTech Connect (OSTI)

    Maxson, Jared; Bazarov, Ivan; Dunham, Bruce; Dobbins, John; Liu, Xianghong; Smolenski, Karl

    2014-09-15

    A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and a movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe the gun's overall mechanical and high voltage design, the surface preparation of components, as well as the clean construction methods. We present high voltage conditioning data using a 50 mm cathode-anode gap, in which the conditioning voltage exceeds 500 kV, as well as at smaller gaps. Finally, we present simulated emittance results obtained from a genetic optimization scheme using voltage values based on the conditioning data. These results indicate that for charges up to 100 pC, a 30 mm gap at 400 kV has equal or smaller 100% emittance than a 50 mm gap at 450 kV, and also a smaller core emittance, when placed as the source for the Cornell energy recovery linac photoinjector with bunch length constrained to be <3 ps rms. For 100 pC up to 0.5 nC charges, the 50 mm gap has larger core emittance than the 30 mm gap, but conversely smaller 100% emittance.

  14. Nano-scaled graphene platelets with a high length-to-width aspect ratio

    DOE Patents [OSTI]

    Zhamu, Aruna; Guo, Jiusheng; Jang, Bor Z.

    2010-09-07

    This invention provides a nano-scaled graphene platelet (NGP) having a thickness no greater than 100 nm and a length-to-width ratio no less than 3 (preferably greater than 10). The NGP with a high length-to-width ratio can be prepared by using a method comprising (a) intercalating a carbon fiber or graphite fiber with an intercalate to form an intercalated fiber; (b) exfoliating the intercalated fiber to obtain an exfoliated fiber comprising graphene sheets or flakes; and (c) separating the graphene sheets or flakes to obtain nano-scaled graphene platelets. The invention also provides a nanocomposite material comprising an NGP with a high length-to-width ratio. Such a nanocomposite can become electrically conductive with a small weight fraction of NGPs. Conductive composites are particularly useful for shielding of sensitive electronic equipment against electromagnetic interference (EMI) or radio frequency interference (RFI), and for electrostatic charge dissipation.

  15. Optimization Notice

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

    Copyright © 2016, Intel Corporation. All rights reserved. *Other names and brands may be claimed as the property of others. Optimization Notice 2 Agenda Scaling with MPI Performance Snapshot Tuning MPI Performance with Intel® Trace Analyzer and Collector Copyright © 2016, Intel Corporation. All rights reserved. *Other names and brands may be claimed as the property of others. Optimization Notice 4 Application Growth Problem Growth Cluster Growth Application/Tool Performance Application Size

  16. Partial Decay Widths of Negative Parity Baryons in the 1/N{sub c} Expansion

    SciTech Connect (OSTI)

    Gonzalez de Urreta, Emiliano; Scoccola, Norberto; Jayalath, Chandala; Goity, Jose

    2013-04-01

    The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6) are analyzed in the framework of the 1/N{sub c} expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/N{sub c} and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are given.

  17. Partial decay widths of negative parity baryons in the 1/N{sub c} expansion

    SciTech Connect (OSTI)

    Gonzalez de Urreta, E. J.; Scoccola, N. N.; Jayalath, C. P.; Goity, J. L.

    2013-03-25

    The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6) are analyzed in the framework of the 1/N{sub c} expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/N{sub c} and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are given.

  18. Engine piston having an insulating air gap

    DOE Patents [OSTI]

    Jarrett, Mark Wayne; Hunold,Brent Michael

    2010-02-02

    A piston for an internal combustion engine has an upper crown with a top and a bottom surface, and a lower crown with a top and a bottom surface. The upper crown and the lower crown are fixedly attached to each other using welds, with the bottom surface of the upper crown and the top surface of the lower crown forming a mating surface. The piston also has at least one centrally located air gap formed on the mating surface. The air gap is sealed to prevent substantial airflow into or out of the air gap.

  19. Columbia River Component Data Gap Analysis

    SciTech Connect (OSTI)

    L. C. Hulstrom

    2007-10-23

    This Data Gap Analysis report documents the results of a study conducted by Washington Closure Hanford (WCH) to compile and reivew the currently available surface water and sediment data for the Columbia River near and downstream of the Hanford Site. This Data Gap Analysis study was conducted to review the adequacy of the existing surface water and sediment data set from the Columbia River, with specific reference to the use of the data in future site characterization and screening level risk assessments.

  20. Gap between jets at the LHC

    SciTech Connect (OSTI)

    Royon, Christophe

    2013-04-15

    We describe a NLL BFKL calculation implemented in the HERWIG MC of the gap between jets cross section, that represent a test of BFKL dynamics. We compare the predictions with recent measurements at the Tevatron and present predictions for the LHC. We also discuss the interesting process of looking for gap between jets in diffractive events when protons are detected in the ATLAS Forward Physics (AFP) detectors.

  1. Report of the working group on precision measurements - measurements of the W boson mass and width.

    SciTech Connect (OSTI)

    Brock, R.; Erler, J.; Kim, Y.-K.; Marciano, W.; Ashmanskas, W.; Baur, U.; Ellison, J.; Lancaster, M.; Nodulman, L.; Rha, J.; Waters, D.; Womersley, J.

    2000-11-29

    We discuss the prospects for measuring the W mass and width in Run II. The basic techniques used to measure M{sub W} are described and the statistical, theoretical and detector-related uncertainties are discussed in detail. Alternative methods of measuring the W mass at the Tevatron and the prospects for M{sub W} measurements at other colliders are also described.

  2. Precision Measurement of {eta} --> {gamma} {gamma} Decay Width via the Primakoff Effect

    SciTech Connect (OSTI)

    Gan, Liping Gin

    2013-08-01

    A precision measurement of the {eta} --> {gamma} {gamma} decay width via the Primakoff effect is underway in Hall D at Jefferson Lab. The decay width will be extracted from measured differential cross sections at forward angles on two light targets, liquid hydrogen and 4He, using a 11.5 GeV tagged photon beam. Results of this experiment will not only potentially resolve a long standing discrepancy between the Primakoff and the collider measurements, but will also reduce the experimental uncertainty by a factor of two on the average value of previous experimental results listed by the Particle Data Group(PDG). It will directly improve all other eta partial decay widths which rely on the accuracy of the eta radiative decay width. The projected 3% precision on the {Gamma}({eta} --> {gamma} {gamma} ) measurement will have a significant impact on the experimental determination of the fundamental parameters in QCD, such as the ratio of light quark masses (m{sub u},m{sub d},m{sub s}) and the {eta} - {eta}' mixing angle. It will be a sensitive probe for understanding QCD symmetries and the origin and the dynamics of QCD symmetry breaking.

  3. Prediction of reinforcement corrosion using corrosion induced cracks width in corroded reinforced concrete beams

    SciTech Connect (OSTI)

    Khan, Inamullah; François, Raoul; Castel, Arnaud

    2014-02-15

    This paper studies the evolution of reinforcement corrosion in comparison to corrosion crack width in a highly corroded reinforced concrete beam. Cracking and corrosion maps of the beam were drawn and steel reinforcement was recovered from the beam to observe the corrosion pattern and to measure the loss of mass of steel reinforcement. Maximum steel cross-section loss of the main reinforcement and average steel cross-section loss between stirrups were plotted against the crack width. The experimental results were compared with existing models proposed by Rodriguez et al., Vidal et al. and Zhang et al. Time prediction models for a given opening threshold are also compared to experimental results. Steel cross-section loss for stirrups was also measured and was plotted against the crack width. It was observed that steel cross-section loss in the stirrups had no relationship with the crack width of longitudinal corrosion cracks. -- Highlights: •Relationship between crack and corrosion of reinforcement was investigated. •Corrosion results of natural process and then corresponds to in-situ conditions. •Comparison with time predicting model is provided. •Prediction of load-bearing capacity from crack pattern was studied.

  4. Turbulent transport regimes and the scrape-off layer heat flux width

    SciTech Connect (OSTI)

    Myra, J. R.; D'Ippolito, D. A.; Russell, D. A.

    2015-04-15

    Understanding the responsible mechanisms and resulting scaling of the scrape-off layer (SOL) heat flux width is important for predicting viable operating regimes in future tokamaks and for seeking possible mitigation schemes. In this paper, we present a qualitative and conceptual framework for understanding various regimes of edge/SOL turbulence and the role of turbulent transport as the mechanism for establishing the SOL heat flux width. Relevant considerations include the type and spectral characteristics of underlying instabilities, the location of the gradient drive relative to the SOL, the nonlinear saturation mechanism, and the parallel heat transport regime. We find a heat flux width scaling with major radius R that is generally positive, consistent with the previous findings [Connor et al., Nucl. Fusion 39, 169 (1999)]. The possible relationship of turbulence mechanisms to the neoclassical orbit width or heuristic drift mechanism in core energy confinement regimes known as low (L) mode and high (H) mode is considered, together with implications for the future experiments.

  5. Bounding the Higgs width at the LHC: complementary results from H→WW

    SciTech Connect (OSTI)

    Campbell, John M.; Ellis, R. Keith; Williams, Ciaran

    2014-03-01

    We investigate the potential of the process gg → H→ WW to provide bounds on the Higgs width. Recent studies using off-shell H→ ZZ events have shown that Run 1 LHC data can constrain the Higgs width, $\\Gamma_H < (25-45) \\Gamma_{H}^{\\rm SM}$. Using 20 fb-1 of 8 TeV ATLAS data, we estimate a bound on the Higgs boson width from the WW channel between $\\Gamma_H < (100-500) \\Gamma_H^{SM}$. The large spread in limits is due to the range of cuts applied in the existing experimental analysis. The stricter cuts designed to search for the on-shell Higgs boson limit the potential number of off-shell events, weakening the constraints. As some of the cuts are lifted the bounds improve. We show that there is potential in the high transverse mass region to produce upper bounds of the order of $(25-50) \\Gamma_H^{SM}$, depending strongly on the level of systematic uncertainty that can be obtained. Thus, if these systematics can be controlled, a constraint on the Higgs boson width from the H → WW$ decay mode can complement a corresponding limit from H → ZZ.

  6. Gas mixtures for spark gap closing switches (Patent) | DOEPatents

    Office of Scientific and Technical Information (OSTI)

    Gas mixtures for spark gap closing switches Title: Gas mixtures for spark gap closing switches Gas mixtures for use in spark gap closing switches comprised of fluorocarbons and low ...

  7. Olene Gap Space Heating Low Temperature Geothermal Facility ...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Olene Gap Space Heating Low Temperature Geothermal Facility Facility Olene Gap Sector Geothermal...

  8. Code Gaps and Future Research Needs of Combustion Safety: Building...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Code Gaps and Future Research Needs of Combustion Safety: Building America Expert Meeting Update Code Gaps and Future Research Needs of Combustion Safety: Building America Expert ...

  9. Development of Low Energy Gap and Fully Regioregular Polythienylenevin...

    Office of Scientific and Technical Information (OSTI)

    Gap and Fully Regioregular Polythienylenevinylene Derivative Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. ...

  10. Tuning the energy gap of conjugated polymer zwitterions for efficient...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Tuning the energy gap of conjugated polymer zwitterions for efficient interlayers and solar cells Citation Details In-Document Search Title: Tuning the energy gap...

  11. FAQS Gap Analysis Qualification Card - Technical Training | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Technical Training FAQS Gap Analysis Qualification Card - Technical Training Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between ...

  12. FAQS Gap Analysis Qualification Card - Industrial Hygiene | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Industrial Hygiene FAQS Gap Analysis Qualification Card - Industrial Hygiene Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between ...

  13. FAQS Gap Analysis Qualification Card - Nuclear Safety Specialist...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Nuclear Safety Specialist FAQS Gap Analysis Qualification Card - Nuclear Safety Specialist Functional Area Qualification Standard Gap Analysis Qualification Cards outline the ...

  14. FAQS Gap Analysis Qualification Card - Quality Assurance | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Quality Assurance FAQS Gap Analysis Qualification Card - Quality Assurance Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between ...

  15. Summary of Gaps and Barriers for Implementing Residential Building...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Gaps and Barriers for Implementing Residential Building Energy Efficiency Strategies Summary of Gaps and Barriers for Implementing Residential Building Energy Efficiency Strategies ...

  16. FAQS Gap Analysis Qualification Card - Senior Technical Safety...

    Office of Environmental Management (EM)

    Senior Technical Safety Manager FAQS Gap Analysis Qualification Card - Senior Technical Safety Manager Functional Area Qualification Standard Gap Analysis Qualification Cards ...

  17. Rapidity gap survival in central exclusive diffraction: Dynamical...

    Office of Scientific and Technical Information (OSTI)

    Rapidity gap survival in central exclusive diffraction: Dynamical mechanisms and uncertainties Citation Details In-Document Search Title: Rapidity gap survival in central exclusive ...

  18. CHP: Connecting the Gap between Markets and Utility Interconnection...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Connecting the Gap between Markets and Utility Interconnection and Tariff Practices, 2006 CHP: Connecting the Gap between Markets and Utility Interconnection and Tariff Practices, ...

  19. Performance and Optimization

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

    Optimization Performance and Optimization Performance Monitoring Last edited: 2012-01-09 12:31:03...

  20. Performance and Optimization

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

    Optimization Performance and Optimization Performance Monitoring Last edited: 2012-01-09 12:31:03

  1. Determining the band gap and mean kinetic energy of atoms from reflection electron energy loss spectra

    SciTech Connect (OSTI)

    Vos, M.; Marmitt, G. G.; Finkelstein, Y.; Moreh, R.

    2015-09-14

    Reflection electron energy loss spectra from some insulating materials (CaCO{sub 3}, Li{sub 2}CO{sub 3}, and SiO{sub 2}) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO{sub 2}, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E{sub gap}){sup 1.5}. For CaCO{sub 3}, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li{sub 2}CO{sub 3} (7.5 eV) is the first experimental estimate.

  2. Apparatus for controlling the scan width of a scanning laser beam

    DOE Patents [OSTI]

    Johnson, Gary W. (Livermore, CA)

    1996-01-01

    Swept-wavelength lasers are often used in absorption spectroscopy applications. In experiments where high accuracy is required, it is desirable to continuously monitor and control the range of wavelengths scanned (the scan width). A system has been demonstrated whereby the scan width of a swept ring-dye laser, or semiconductor diode laser, can be measured and controlled in real-time with a resolution better than 0.1%. Scan linearity, or conformity to a nonlinear scan waveform, can be measured and controlled. The system of the invention consists of a Fabry-Perot interferometer, three CAMAC interface modules, and a microcomputer running a simple analysis and proportional-integral control algorithm. With additional modules, multiple lasers can be simultaneously controlled. The invention also includes an embodiment implemented on an ordinary PC with a multifunction plug-in board.

  3. An indirect measurement of the width of the w boson at the D0 experiment

    SciTech Connect (OSTI)

    Telford, Paul; /Manchester U.

    2006-08-01

    This thesis presents an indirect measurement of the width of the W boson using data collected at the D0 experiment, a multipurpose particle detector utilizing the Fermilab Tevatron. The W width was determined from the ratio of W {yields} {mu}{nu} to Z {yields} {mu}{sup +}{mu}{sup -} cross sections to be {Gamma}{sub W} = 2168 {+-} 22(stat) {+-} 62(syst){sub -16}{sup +24}(pdf) {+-} 4(other) MeV, in good agreement with the Standard Model prediction and other experimental measurements. In addition there is a description of how work made towards this measurement has been used to improve the parameterized detector simulation, a vital tool in the obtention of physics results from signals observed in the detector, and in estimating the uncertainty due to choice of PDF, which is of interest for all measurements made at hadron colliders.

  4. Apparatus for controlling the scan width of a scanning laser beam

    DOE Patents [OSTI]

    Johnson, G.W.

    1996-10-22

    Swept-wavelength lasers are often used in absorption spectroscopy applications. In experiments where high accuracy is required, it is desirable to continuously monitor and control the range of wavelengths scanned (the scan width). A system has been demonstrated whereby the scan width of a swept ring-dye laser, or semiconductor diode laser, can be measured and controlled in real-time with a resolution better than 0.1%. Scan linearity, or conformity to a nonlinear scan waveform, can be measured and controlled. The system of the invention consists of a Fabry-Perot interferometer, three CAMAC interface modules, and a microcomputer running a simple analysis and proportional-integral control algorithm. With additional modules, multiple lasers can be simultaneously controlled. The invention also includes an embodiment implemented on an ordinary PC with a multifunction plug-in board. 8 figs.

  5. Relativistic calculation of the width of the {theta}{sup +}(1540) pentaquark

    SciTech Connect (OSTI)

    Li Hu; Shakin, C.M.; Li Xiangdong

    2005-06-01

    We calculate the width of the {theta}{sup +}(1540) pentaquark in a relativistic model in which the pentaquark is considered to be composed of a scalar diquark and a spin 1/2 triquark. We consider both positive and negative parity for the pentaquark. There is a single parameter in our model which we vary and which describes the size of the pentaquark. If the pentaquark size is somewhat smaller than that of the nucleon, we find quite small widths for the pentaquark of about 1 MeV or less. Our model of confinement plays an important role in our analysis and makes it possible to use Feynman diagrams to describe the decay of the pentaquark.

  6. Homolumo gap from dynamical energy levels

    SciTech Connect (OSTI)

    Andric, I.; Jonke, L.; Jurman, D.; Nielsen, H. B.

    2009-11-15

    We introduce a dynamical matrix model where the matrix is interpreted as a Hamiltonian representing interaction of a bosonic system with a single fermion. We show how a system of second-quantized fermions influences the ground state of the whole system by producing a gap between the highest eigenvalue of the occupied single-fermion states and the lowest eigenvalue of the unoccupied single-fermion states. We describe the development of the gap in both the strong and weak coupling regimes, while for the intermediate coupling strength we expect formation of homolumo kinks.

  7. Natural Gas Engine Development Gaps (Presentation)

    SciTech Connect (OSTI)

    Zigler, B.T.

    2014-03-01

    A review of current natural gas vehicle offerings is presented for both light-duty and medium- and heavy-duty applications. Recent gaps in the marketplace are discussed, along with how they have been or may be addressed. The stakeholder input process for guiding research and development needs via the Natural Gas Vehicle Technology Forum (NGVTF) to the U.S. Department of Energy and the California Energy Commission is reviewed. Current high-level natural gas engine development gap areas are highlighted, including efficiency, emissions, and the certification process.

  8. Band gap and defect states of MgO thin films investigated using reflection electron energy loss spectroscopy

    SciTech Connect (OSTI)

    Heo, Sung; Cho, Eunseog; Lee, Hyung-Ik; Park, Gyeong Su; Kang, Hee Jae; Nagatomi, T.; Choi, Pyungho; Choi, Byoung-Deog

    2015-07-15

    The band gap and defect states of MgO thin films were investigated by using reflection electron energy loss spectroscopy (REELS) and high-energy resolution REELS (HR-REELS). HR-REELS with a primary electron energy of 0.3 keV revealed that the surface F center (FS) energy was located at approximately 4.2 eV above the valence band maximum (VBM) and the surface band gap width (E{sub g}{sup S}) was approximately 6.3 eV. The bulk F center (F{sub B}) energy was located approximately 4.9 eV above the VBM and the bulk band gap width was about 7.8 eV, when measured by REELS with 3 keV primary electrons. From a first-principles calculation, we confirmed that the 4.2 eV and 4.9 eV peaks were F{sub S} and F{sub B}, induced by oxygen vacancies. We also experimentally demonstrated that the HR-REELS peak height increases with increasing number of oxygen vacancies. Finally, we calculated the secondary electron emission yields (γ) for various noble gases. He and Ne were not influenced by the defect states owing to their higher ionization energies, but Ar, Kr, and Xe exhibited a stronger dependence on the defect states owing to their small ionization energies.

  9. Dome – like variation of the superconducting gap anisotropy in Fe-based superconductors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Prozorov, R.; Cho, K.; Kim, H.; Tanatar, M. A.

    2013-07-17

    Experiments performed on different iron-based superconductors suggest a variety of possible structures of the superconducting energy gap, both nodeless and nodal. To understand the pairing mechanisms, it is important to identify common features in the behavior of different materials. Measurements of the temperature - dependent London penetration depth provide important information on the structure of the superconducting gap. We show that despite significant differences between different iron - based superconductors, there is a universal trend: the gap is least anisotropic at the optimal doping and its anisotropy increases upon the departure towards underdoped and overdoped ends of the ''superconducting dome''.more » As a result, this trend is not related to the presence of the long-range magnetic order in the underdoped state.« less

  10. Analysis of photonic band gaps in two-dimensional photonic crystals with rods covered by a thin interfacial layer

    SciTech Connect (OSTI)

    Trifonov, T.; Marsal, L.F.; Pallares, J.; Rodriguez, A.; Alcubilla, R.

    2004-11-15

    We investigate different aspects of the absolute photonic band gap (PBG) formation in two-dimensional photonic structures consisting of rods covered with a thin dielectric film. Specifically, triangular and honeycomb lattices in both complementary arrangements, i.e., air rods drilled in silicon matrix and silicon rods in air, are studied. We consider that the rods are formed of a dielectric core (silicon or air) surrounded by a cladding layer of silicon dioxide (SiO{sub 2}), silicon nitride (Si{sub 3}N{sub 4}), or germanium (Ge). Such photonic lattices present absolute photonic band gaps, and we study the evolution of these gaps as functions of the cladding material and thickness. Our results show that in the case of air rods in dielectric media the existence of dielectric cladding reduces the absolute gap width and may cause complete closure of the gap if thick layers are considered. For the case of dielectric rods in air, however, the existence of a cladding layer can be advantageous and larger absolute PBG's can be achieved.

  11. Spark gap device for precise switching

    DOE Patents [OSTI]

    Boettcher, G.E.

    1984-10-02

    A spark gap device for precise switching of an energy storage capacitor into an exploding bridge wire load is disclosed. Niobium electrodes having a melting point of 2,415 degrees centigrade are spaced apart by an insulating cylinder to define a spark gap. The electrodes are supported by conductive end caps which, together with the insulating cylinder, form a hermetically sealed chamber filled with an inert, ionizable gas, such as pure xenon. A quantity of solid radioactive carbon-14 within the chamber adjacent the spark gap serves as a radiation stabilizer. The sides of the electrodes and the inner wall of the insulating cylinder are spaced apart a sufficient distance to prevent unwanted breakdown initiation. A conductive sleeve may envelop the outside of the insulating member from the midpoint of the spark gap to the cap adjacent the cathode. The outer metallic surfaces of the device may be coated with a hydrogen-impermeable coating to lengthen the shelf life and operating life of the device. The device breaks down at about 1,700 volts for input voltage rates up to 570 volts/millisecond and allows peak discharge currents of up to 3,000 amperes from a 0.3 microfarad energy storage capacitor for more than 1,000 operations. 3 figs.

  12. Five Facts About the Gender Pay Gap

    Office of Energy Efficiency and Renewable Energy (EERE)

    Over the past century, American women have made tremendous strides in increasing their labor market experience and their skills. On Equal Pay Day, however, we focus on a stubborn and troubling fact: Despite women’s gains, a large gender pay gap still exists.

  13. Spark gap device for precise switching

    DOE Patents [OSTI]

    Boettcher, Gordon E.

    1984-01-01

    A spark gap device for precise switching of an energy storage capacitor into an exploding bridge wire load is disclosed. Niobium electrodes having a melting point of 2,415 degrees centrigrade are spaced apart by an insulating cylinder to define a spark gap. The electrodes are supported by conductive end caps which, together with the insulating cylinder, form a hermetically sealed chamber filled with an inert, ionizable gas, such as pure xenon. A quantity of solid radioactive carbon-14 within the chamber adjacent the spark gap serves as a radiation stabilizer. The sides of the electrodes and the inner wall of the insulating cylinder are spaced apart a sufficient distance to prevent unwanted breakdown initiation. A conductive sleeve may envelop the outside of the insulating member from the midpoint of the spark gap to the cap adjacent the cathode. The outer metallic surfaces of the device may be coated with a hydrogen-impermeable coating to lengthen the shelf life and operating life of the device. The device breaks down at about 1,700 volts for input voltage rates up to 570 volts/millisecond and allows peak discharge currents of up to 3,000 amperes from a 0.3 microfarad energy storage capacitor for more than 1,000 operations.

  14. FINAL REPORT ON GDE GAP CELL

    SciTech Connect (OSTI)

    Herman, D.; Summers, W.; Danko, E.

    2009-09-28

    A project has been undertaken to develop an electrochemical cell and support equipment for evaluation of a gas diffusion electrode-based, narrow-electrolyte-gap anode for SO{sub 2} oxidation in the hydrogen production cycle of the hybrid sulfur (HyS) process. The project supported the HyS development program at the Savannah River National Lab (SRNL). The benefits of using a gas diffusion electrode in conjunction with the narrow anolyte gap are being determined through electrochemical polarization testing under a variety conditions, and by comparison to results produced by SRNL and others using anode technologies that have no anolyte gap. These test results indicate that the NGA cell has low resistance suitable for use in the HyS electrolyzer, exhibits good efficiency at high current densities compared to the direct feed HyS electrolyzer, and indicates robust performance in extended testing over 65 hours. Seepage episodes were mostly caused by port clogging, which can be mitigated in future designs through minor modifications to the hardware. Significant reductions in sulfur crossover have not yet been demonstrated in the NGA configuration compared to in-house direct feed testing, but corroborative sulfur layer analysis is as yet incomplete. Further testing in a single-pass anolyte configuration is recommended for complete evaluation of steady-state electrochemical efficiency and SO{sub 2} crossover in the narrow gap configuration.

  15. Impacts of Multileaf Collimators Leaf Width on Intensity-Modulated Radiotherapy Planning for Nasopharyngeal Carcinoma: Analysis of Two Commercial Elekta Devices

    SciTech Connect (OSTI)

    Wang Shichao; Gong Youling; Xu Qingfeng; Bai Sen; Lu You; Jiang Qingfeng; Chen Nianyong

    2011-07-01

    We compared the impacts of multileaf collimator (MLC) widths (standard MLC width of 10 mm [SMLC] and micro-MLC width of 4 mm [MMLC]) on intensity-modulated radiotherapy (IMRT) planning for nasopharyngeal carcinoma (NPC). Ten patients with NPC were recruited in this study. In each patient's case, plans were generated with the same machine setup parameter and optimizing methods in a treatment planning system according to 2 commercial Elekta MLC devices. All of the parameters were collected from dose-volume histograms of paired plans and evaluated. The average conformity index (CI) and homogeneous index (HI) for the planning gross target volume in IMRT plans with MMLC were 0.790 {+-} 0.036 and 1.062 {+-} 0.011, respectively. Data in plans with SMLC were 0.754 {+-} 0.038 and 1.070 {+-} 0.010, respectively. The differences were statistically significant (p < 0.05). Compared with CI and HI for planning target volume in paired plans, data with MMLC obviously were better than those with SMLC (CI: 0.858 {+-} 0.026 vs. 0.850 {+-} 0.021, p < 0.05; and HI: 1.185 {+-} 0.011 vs. 1.195 {+-} 0.011, p < 0.05). However, there was no statistical significance between evaluated parameters (Dmean, Dmax, D{sub 5}, gEUD, or NTCP) for organs at risk (OARs) in the 2 paired IMRT plans. According to these two kinds of Elekta MLC devices, IMRT plans with the MMLC have significant advantages in dose coverage for the targets, with more efficiency in treatment for NPC but fail to improve dose sparing of the OARs.

  16. Measurement of the in-medium Φ-meson width in proton–nucleus collisions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Polyanskiy, A.; Hartmann, M.; Kiselev, Yu. T.; Paryev, E. Ya.; Büscher, M.; Chiladze, D.; Dymov, S.; Dzyuba, A.; Gebel, R.; Hejny, V.; et al

    2010-10-28

    We measured the production of Φ mesons in the collisions of 2.83 GeV protons with C, Cu, Ag, and Au at forward angles via the Φ → K+K- decay using the COSY-ANKE magnetic spectrometer. The Φ meson production cross section follows a target mass dependence of A0.56±0.02 in the momentum region of 0.6-1.6 GeV/c. Moreover, the comparison of the data with model calculations suggests that the in-medium Φ width is about an order of magnitude larger than its free value.

  17. Measurement of the in-medium phi-meson width in proton-nucleus collisions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Polyanskiy, A; Kiselev, Yu T; Paryev, E Ya; Buscher, M; Chiladze, D; Dymov, S; Dzyuba, A; Gebel, R; Hejny, V; Kampfer, B; et al

    2011-01-01

    The production of phi mesons in the collisions of 2.83 GeV protons with C, Cu, Ag, and Au at forward angles has been measured via the phi -> K+K- decay using the COSY-ANKE magnetic spectrometer. The phi meson production cross section follows a target mass dependence of A^0.56+/-0.02 in the momentum region of 0.6-1.6 GeV/c. The comparison of the data with model calculations suggests that the in-medium phi width is about an order of magnitude larger than its free value.

  18. Dynamically Generated Mott Gap from Holography

    SciTech Connect (OSTI)

    Edalati, Mohammad; Leigh, Robert G.; Phillips, Philip W.

    2011-03-04

    In the fermionic sector of top-down approaches to holographic systems, one generically finds that the fermions are coupled to gravity and gauge fields in a variety of ways, beyond minimal coupling. In this Letter, we take one such interaction--a Pauli, or dipole, interaction--and study its effects on fermion correlators. We find that this interaction modifies the fermion spectral density in a remarkable way. As we change the strength of the interaction, we find that spectral weight is transferred between bands, and beyond a critical value, a gap emerges in the fermion density of states. A possible interpretation of this bulk interaction then is that it drives the dynamical formation of a (Mott) gap, in the absence of continuous symmetry breaking.

  19. Codoped direct-gap semiconductor scintillators

    DOE Patents [OSTI]

    Derenzo, Stephen E.; Bourret-Courchesne, Edith; Weber, Marvin J.; Klintenberg, Mattias K.

    2006-05-23

    Fast, bright inorganic scintillators at room temperature are based on radiative electron-hole recombination in direct-gap semiconductors, e.g. CdS and ZnO. The direct-gap semiconductor is codoped with two different impurity atoms to convert the semiconductor to a fast, high luminosity scintillator. The codopant scheme is based on dopant band to dopant trap recombination. One dopant provides a significant concentration of carriers of one type (electrons or holes) and the other dopant traps carriers of the other type. Examples include CdS:In,Te; CdS:In,Ag; CdS:In,Na; ZnO:Ga,P; ZnO:Ga,N; ZnO:Ga,S; and GaN:Ge,Mg.

  20. Codoped direct-gap semiconductor scintillators

    DOE Patents [OSTI]

    Derenzo, Stephen Edward; Bourret-Courchesne, Edith; Weber, Marvin J.; Klintenberg, Mattias K.

    2008-07-29

    Fast, bright inorganic scintillators at room temperature are based on radiative electron-hole recombination in direct-gap semiconductors, e.g. CdS and ZnO. The direct-gap semiconductor is codoped with two different impurity atoms to convert the semiconductor to a fast, high luminosity scintillator. The codopant scheme is based on dopant band to dopant trap recombination. One dopant provides a significant concentration of carriers of one type (electrons or holes) and the other dopant traps carriers of the other type. Examples include CdS:In,Te; CdS:In,Ag; CdS:In,Na; ZnO:Ga,P; ZnO:Ga,N; ZnO:Ga,S; and GaN:Ge,Mg.

  1. Gap Assessment in the Emergency Response Community

    SciTech Connect (OSTI)

    Barr, Jonathan L.; Burtner, Edwin R.; Pike, William A.; Peddicord, Annie M Boe; Minsk, Brian S.

    2010-09-27

    This report describes a gap analysis of the emergency response and management (EM) community, performed during the fall of 2009. Pacific Northwest National Laboratory (PNNL) undertook this effort to identify potential improvements to the functional domains in EM that could be provided by the application of current or future technology. To perform this domain-based gap analysis, PNNL personnel interviewed subject matter experts (SMEs) across the EM domain; to make certain that the analyses reflected a representative view of the community, the SMEs were from a variety of geographic areas and from various sized communities (urban, suburban, and rural). PNNL personnel also examined recent and relevant after-action reports and U.S. Government Accountability Office reports.

  2. [SIAM conference on optimization

    SciTech Connect (OSTI)

    Not Available

    1992-05-10

    Abstracts are presented of 63 papers on the following topics: large-scale optimization, interior-point methods, algorithms for optimization, problems in control, network optimization methods, and parallel algorithms for optimization problems.

  3. Fabrication of photonic band gap materials

    DOE Patents [OSTI]

    Constant, Kristen; Subramania, Ganapathi S.; Biswas, Rana; Ho, Kai-Ming

    2002-01-15

    A method for forming a periodic dielectric structure exhibiting photonic band gap effects includes forming a slurry of a nano-crystalline ceramic dielectric or semiconductor material and monodisperse polymer microspheres, depositing a film of the slurry on a substrate, drying the film, and calcining the film to remove the polymer microspheres therefrom. The film may be cold-pressed after drying and prior to calcining. The ceramic dielectric or semiconductor material may be titania, and the polymer microspheres may be polystyrene microspheres.

  4. Spark gap switch with spiral gas flow

    DOE Patents [OSTI]

    Brucker, John P.

    1989-01-01

    A spark gap switch having a contaminate removal system using an injected gas. An annular plate concentric with an electrode of the switch defines flow paths for the injected gas which form a strong spiral flow of the gas in the housing which is effective to remove contaminates from the switch surfaces. The gas along with the contaminates is exhausted from the housing through one of the ends of the switch.

  5. Bridging the Gaps on Prepaid Utility Service

    Broader source: Energy.gov [DOE]

    Prepaid utility service — which is an alternative payment option in which consumers buy a dollar amount of electricity, and utilities deduct energy usage from that balance as it is used — is one area where these changes converge. The Office of Electricity Delivery and Energy Reliability’s report entitled “Bridging the Gaps on Prepaid Utility Service” examines utilities’ and consumers’ experiences with prepay.

  6. HIGH VOLTAGE, HIGH CURRENT SPARK GAP SWITCH

    DOE Patents [OSTI]

    Dike, R.S.; Lier, D.W.; Schofield, A.E.; Tuck, J.L.

    1962-04-17

    A high voltage and current spark gap switch comprising two main electrodes insulatingly supported in opposed spaced relationship and a middle electrode supported medially between the main electrodes and symmetrically about the median line of the main electrodes is described. The middle electrode has a perforation aligned with the median line and an irradiation electrode insulatingly supported in the body of the middle electrode normal to the median line and protruding into the perforation. (AEC)

  7. Dependence of various SOL widths on plasma current and density in NSTX H-mode plasmas

    SciTech Connect (OSTI)

    Ahn, J; Maingi, R; Boedo, J; Soukhanovskii, V A

    2009-02-12

    The dependence of various SOL widths on the line-averaged density ({ovr n}{sub e}) and plasma current (l{sub p}) for the quiescent H-mode plasmas with Type-V ELMs in the National Spherical Torus Experiment (NSTX) was investigated. It is found that the heat flux SOL width ({lambda}{sub q}), measured by the IR camera, is virtually insensitive to {ovr n}{sub e} and has a strong negative dependence on l{sub p}. This insensitivity of {lambda}{sub q} to {ovr n}{sub e} is consistent with the scaling law from JET H-mode plasmas that shows a very weak dependence on the upstream density. The electron temperature, ion saturation current density, electron density, and electron pressure decay lengths ({lambda}{sub Te}, {lambda}{sub jsat}, {lambda}{sub ne}, and {lambda}{sub pe}, respectively) measured by the probe showed that {lambda}{sub Te} and {lambda}{sub jsat} have strong negative dependence on l{sub p}, whereas {lambda}{sub ne} and {lambda}{sub pe} revealed only a little or no dependence. The dependence of {lambda}{sub Te} on l{sub p} is consistent with the scaling law in the literature while {lambda}{sub ne} and {lambda}{sub pe} dependence shows a different trend.

  8. A Direct Top-Quark Width Measurement from Lepton + Jets Events at CDF II

    SciTech Connect (OSTI)

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2010-08-01

    We present a measurement of the top-quark width using t{bar t} events produced in p{bar p} collisions at Fermilab's Tevatron collider and collected by the CDF II detector. In the mode where the top quark decays to a W boson and a bottom quark, we select events in which one W decays leptonically and the other hadronically (lepton + jets channel) . From a data sample corresponding to 4.3 fb{sup -1} of integrated luminosity, we identify 756 candidate events. The top-quark mass and the mass of W boson that decays hadronically are reconstructed for each event and compared with templates of different top-quark widths ({Lambda}{sub t}) and deviations from nominal jet energy scale ({Delta}{sub JES}) to perform a simultaneous fit for both parameters, where {Delta}{sub JES} is used for the in situ calibration of the jet energy scale. By applying a Feldman-Cousins approach, we establish an upper limit at 95% confidence level (CL) of {Lambda}{sub t} < 7.6 GeV and a two-sided 68% CL interval of 0.3 GeV < {Lambda}{sub t} < 4.4 GeV for a top-quark mass of 172.5 GeV/c{sup 2}, which are consistant with the standard model prediction. This is the first direct measurement of {Lambda}{sub t} to set a lower limit with 68% CL.

  9. Method and apparatus for pulse width modulation control of an AC induction motor

    DOE Patents [OSTI]

    Geppert, Steven; Slicker, James M.

    1984-01-01

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

  10. Effects of Bismuth on Wide-Depletion-Width GaInNAs Solar Cells

    SciTech Connect (OSTI)

    Ptak, A. J.; France, R.; Jiang, C.-S.; Reedy, R. C.

    2008-05-01

    GaInNAs solar cells could be useful in next-generation multijunction solar cells if issues surrounding low photocurrents and photovoltages are surmounted. Wide-depletion-width devices generate significant photocurrent using a p-i-n structure grown by molecular beam epitaxy, but these depletion widths are only realized in a region of parameter space that leads to rough surface morphologies. Here, bismuth is explored as a surfactant for the growth of GaInNAs solar cells. Very low fluxes of Bi are effective at maintaining smooth surfaces, even at high growth temperatures and In contents. However, Bi also increases the net donor concentration in these materials, manifested in our n-on-p device structures as a pn-junction that moves deeper into the base layer with increasing Bi fluxes. Quantum efficiency modeling and scanning kelvin probe microscopy measurements confirm the type conversion of the base layer from p type to n type. Bi incorporation in GaAsBi samples shows signs of surface segregation, leading to a finite buildup time, and this effect may lead to slow changes in the electrical properties of the GaInNAs(Bi) devices. Bi also appears to create a defect level, although this defect level is not deleterious enough to increase the dark current in the devices.

  11. Diffraction limited focusing and routing of gap plasmons by a metal-dielectric-metal lens

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dennis, Brian S.; Czaplewski, David A.; Haftel, Michael I.; Lopez, Daniel; Blumberg, Girsh; Aksyuk, Vladimir

    2015-08-12

    Passive optical elements can play key roles in photonic applications such as plasmonic integrated circuits. Here we experimentally demonstrate passive gap-plasmon focusing and routing in two-dimensions. This is accomplished using a high numerical-aperture metal-dielectric-metal lens incorporated into a planar-waveguide device. Fabrication via metal sputtering, oxide deposition, electron- and focused-ion- beam lithography, and argon ion-milling is reported on in detail. Diffraction-limited focusing is optically characterized by sampling out-coupled light with a microscope. The measured focal distance and full-width-half-maximum spot size agree well with the calculated lens performance. The surface plasmon polariton propagation length is measured by sampling light from multiple out-couplermoreslits.less

  12. Optimizing optical absorption of TiO{sub 2} by alloying with...

    Office of Scientific and Technical Information (OSTI)

    Title: Optimizing optical absorption of TiOsub 2 by alloying with TiSsub 2 TiOsub 2 is an attractive material for photocatalytic water splitting, but its band gap is too ...

  13. Width dependent transition of quantized spin-wave modes in Ni{sub 80}Fe{sub 20} square nanorings

    SciTech Connect (OSTI)

    Banerjee, Chandrima; Saha, Susmita; Barman, Saswati; Barman, Anjan, E-mail: abarman@bose.res.in [Thematic Unit of Excellence on Nanodevice Technology, Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098 (India); Rousseau, Olivier [CEMS-RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Otani, YoshiChika [CEMS-RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

    2014-10-28

    We investigated optically induced ultrafast magnetization dynamics in square shaped Ni{sub 80}Fe{sub 20} nanorings with varying ring width. Rich spin-wave spectra are observed whose frequencies showed a strong dependence on the ring width. Micromagnetic simulations showed different types of spin-wave modes, which are quantized upto very high quantization number. In the case of widest ring, the spin-wave mode spectrum shows quantized modes along the applied field direction, which is similar to the mode spectrum of an antidot array. As the ring width decreases, additional quantization in the azimuthal direction appears causing mixed modes. In the narrowest ring, the spin-waves exhibit quantization solely in azimuthal direction. The different quantization is attributed to the variation in the internal field distribution for different ring width as obtained from micromagnetic analysis and supported by magnetic force microscopy.

  14. Buffalo Gap 3 Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    3 Wind Farm Jump to: navigation, search Name Buffalo Gap 3 Wind Farm Facility Buffalo Gap 3 Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner...

  15. Interface Ferroelectric Transition near the Gap-Opening Temperature...

    Office of Scientific and Technical Information (OSTI)

    Interface Ferroelectric Transition near the Gap-Opening Temperature in a Single-Unit-Cell ... Gap-Opening Temperature in a Single-Unit-Cell FeSe Film Grown on Nb-Doped SrTiO 3 ...

  16. ROSS Skills, Knowledge, and Abilities Training Evaluation. Gaps and Recommendations

    SciTech Connect (OSTI)

    Ala, Maureen; Gruidl, Jeremiah; Buddemeier, Brooke

    2015-09-30

    This document describes the development of the ROSS SKAs, the cross-mapping of the SKAs to the available training, identifies gaps in the SKA and training, and provides recommendations to address those gaps.

  17. Vehicle Codes and Standards: Overview and Gap Analysis

    SciTech Connect (OSTI)

    Blake, C.; Buttner, W.; Rivkin, C.

    2010-02-01

    This report identifies gaps in vehicle codes and standards and recommends ways to fill the gaps, focusing on six alternative fuels: biodiesel, natural gas, electricity, ethanol, hydrogen, and propane.

  18. Coexistence of a pseudogap and a superconducting gap for the...

    Office of Scientific and Technical Information (OSTI)

    Coexistence of a pseudogap and a superconducting gap for the high - T c superconductor La ... Title: Coexistence of a pseudogap and a superconducting gap for the high - T c ...

  19. Reduced model simulations of the scrape-off-layer heat-flux width and comparison with experiment

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Myra, J. R.; Russell, D. A.; D’Ippolito, D. A.; Ahn, J.-W.; Maingi, R.; Maqueda, R. J.; Lundberg, D. P.; Stotler, D. P.; Zweben, S. J.; Boedo, J.; et al

    2011-01-01

    Reduced model simulations of turbulence in the edge and scrape-off-layer (SOL) region of a spherical torus or tokamak plasma are employed to address the physics of the scrape-off-layer heat flux width. The simulation model is an electrostatic two-dimensional fluid turbulence model, applied in the plane perpendicular to the magnetic field at the outboard midplane of the torus. The model contains curvature-driven-interchange modes, sheath losses, and both perpendicular turbulent diffusive and convective (blob) transport. These transport processes compete with classical parallel transport to set the SOL width. Midplane SOL profiles of density, temperature and parallel heat flux are obtained from themore » simulation and compared with experimental results from the National Spherical Torus Experiment (NSTX) to study the scaling of the heat flux width with power and plasma current. It is concluded that midplane turbulence is the main contributor to the SOL heat flux width for the low power H-mode discharges studied, while additional physics is required to explain the plasma current scaling of the SOL heat flux width observed experimentally in higher power discharges. Intermittent separatrix spanning convective cells are found to be the main mechanism that sets the near-SOL width in the simulations. The roles of sheared flows and blob trapping vs. emission are discussed.« less

  20. FAQS Gap Analysis Qualification Card - Waste Management | Department of

    Office of Environmental Management (EM)

    Energy Technical Training FAQS Gap Analysis Qualification Card - Technical Training Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard. Technical Training Gap Analysis Qualification Card (83.77 KB) More Documents & Publications DOE-STD-1179-2004 DOE-HDBK-1078-94 FAQS Reference Guide - Technical Training Energy

    Waste Management FAQS Gap Analysis Qualification Card - Waste Management

  1. Fact #609: February 8, 2010 The Transportation Petroleum Gap | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy 09: February 8, 2010 The Transportation Petroleum Gap Fact #609: February 8, 2010 The Transportation Petroleum Gap In 1989 the transportation sector petroleum consumption surpassed U.S. petroleum production for the first time, creating a gap that must be met with imports of petroleum. By the year 2035, transportation petroleum consumption is expected to grow to more than 17 million barrels per day; at that time, the gap between U.S. production and transportation consumption will be

  2. Minority Serving Institutions (MSIs): Bridging the Gap between Federal

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Agencies and MSIs | Department of Energy Minority Serving Institutions (MSIs): Bridging the Gap between Federal Agencies and MSIs Minority Serving Institutions (MSIs): Bridging the Gap between Federal Agencies and MSIs Different Minority Serving institutions Minority Serving Institutions (MSIs): Bridging the Gap between Federal Agencies and MSIs (1.04 MB) More Documents & Publications Bridging the Gap Between Federal Agencies and MSIs Research and Services at the Alabama A&M

  3. Technical Standards, MELCOR - Gap Analysis - May 3, 2004 | Department of

    Office of Environmental Management (EM)

    Energy MELCOR - Gap Analysis - May 3, 2004 Technical Standards, MELCOR - Gap Analysis - May 3, 2004 May 3, 2004 Software Quality Assurance Improvement Plan: MELCOR Gap Analysis This report documents the outcome of an evaluation of the Software Quality Assurance (SQA) attributes of the MELCOR computer code for leak path factor applications, relative to established software requirements. This evaluation, a "gap analysis," is performed to meet Commitment 4.2.1.3 of the Department of

  4. Functional Area Qualification Standard Gap Analysis Qualification Cards

    Broader source: Energy.gov [DOE]

    FAQS Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  5. Single line-of-sight dual energy backlighter for mix width experiments

    SciTech Connect (OSTI)

    Baker, K. L. Glendinning, S. G.; Martinez, D.; Dittrich, T. R.; MacLaren, S. A.; Felker, S.; Seugling, R.; Doane, D.; Wallace, R.; Guymer, T. M.; Moore, A. S.; Whiting, N.; Sorce, C.

    2014-11-15

    We present a diagnostic technique used to spatially multiplex two x-ray radiographs of an object onto a detector along a single line-of-sight. This technique uses a thin, <2 μm, cosputtered backlighter target to simultaneously produce both Ni and Zn He{sub α} emission. A Ni picket fence filter, 500 μm wide bars and troughs, is then placed in front of the detector to pass only the Ni He{sub α} emission in the bar region and both energies in the trough region thereby spatially multiplexing the two radiographs on a single image. Initial experimental results testing the backlighter spectrum are presented along with simulated images showing the calculated radiographic images though the nickel picket fence filter which are used to measure the mix width in an accelerated nickel foam.

  6. Turbine blade tip gap reduction system

    SciTech Connect (OSTI)

    Diakunchak, Ihor S.

    2012-09-11

    A turbine blade sealing system for reducing a gap between a tip of a turbine blade and a stationary shroud of a turbine engine. The sealing system includes a plurality of flexible seal strips extending from a pressure side of a turbine blade generally orthogonal to the turbine blade. During operation of the turbine engine, the flexible seal strips flex radially outward extending towards the stationary shroud of the turbine engine, thereby reducing the leakage of air past the turbine blades and increasing the efficiency of the turbine engine.

  7. Quantum chaos and thermalization in gapped systems

    SciTech Connect (OSTI)

    Rigol, Marcos [Department of Physics, Georgetown University, Washington, DC 20057 (United States); Santos, Lea F. [Department of Physics, Yeshiva University, New York, New York 10016 (United States)

    2010-07-15

    We investigate the onset of thermalization and quantum chaos in finite one-dimensional gapped systems of hard-core bosons. Integrability in these systems is broken by next-nearest-neighbor repulsive interactions, which also generate a superfluid to insulator transition. By employing full exact diagonalization, we study chaos indicators and few-body observables. We show that with increasing system size, chaotic behavior is seen over a broader range of parameters and, in particular, deeper into the insulating phase. Concomitantly, we observe that, as the system size increases, the eigenstate thermalization hypothesis extends its range of validity inside the insulating phase and is accompanied by the thermalization of the system.

  8. Next Generation Nuclear Plant GAP Analysis Report

    SciTech Connect (OSTI)

    Ball, Sydney J; Burchell, Timothy D; Corwin, William R; Fisher, Stephen Eugene; Forsberg, Charles W.; Morris, Robert Noel; Moses, David Lewis

    2008-12-01

    As a follow-up to the phenomena identification and ranking table (PIRT) studies conducted recently by NRC on next generation nuclear plant (NGNP) safety, a study was conducted to identify the significant 'gaps' between what is needed and what is already available to adequately assess NGNP safety characteristics. The PIRT studies focused on identifying important phenomena affecting NGNP plant behavior, while the gap study gives more attention to off-normal behavior, uncertainties, and event probabilities under both normal operation and postulated accident conditions. Hence, this process also involved incorporating more detailed evaluations of accident sequences and risk assessments. This study considers thermal-fluid and neutronic behavior under both normal and postulated accident conditions, fission product transport (FPT), high-temperature metals, and graphite behavior and their effects on safety. In addition, safety issues related to coupling process heat (hydrogen production) systems to the reactor are addressed, given the limited design information currently available. Recommendations for further study, including analytical methods development and experimental needs, are presented as appropriate in each of these areas.

  9. Superconducting gap evolution in overdoped BaFe₂(As1-xPx)₂ single crystals through nanocalorimetry

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Campanini, D.; Diao, Z.; Fang, L.; Kwok, W.-K.; Welp, U.; Rydh, A.

    2015-06-18

    We report on specific heat measurements on clean overdoped BaFe₂(As1-xPx)₂ single crystals performed with a high resolution membrane-based nanocalorimeter. A nonzero residual electronic specific heat coefficient at zero temperature γr=C/T|T→0 is seen for all doping compositions, indicating a considerable fraction of the Fermi surface ungapped or having very deep minima. The remaining superconducting electronic specific heat is analyzed through a two-band s-wave α model in order to investigate the gap structure. Close to optimal doping we detect a single zero-temperature gap of Δ₀~5.3 me V, corresponding to Δ₀/kBTc ~ 2.2. Increasing the phosphorus concentration x, the main gap reduces tillmore » a value of Δ₀ ~ 1.9 meV for x = 0.55 and a second weaker gap becomes evident. From the magnetic field effect on γr, all samples however show similar behavior [γr(H) - γr (H = 0)∝ Hn, with n between 0.6 and 0.7]. This indicates that, despite a considerable redistribution of the gap weights, the total degree of gap anisotropy does not change drastically with doping.« less

  10. Propagation or failure of detonation across an air gap in an LX-17 column: continuous time-dependent detonation or shock speed using the Embedded Fiber Optic (EFO) technique

    SciTech Connect (OSTI)

    Hare, D E; Chandler, J B; Compton, S M; Garza, R G; Grimsley, D A; Hernandez, A; Villafana, R J; Wade, J T; Weber, S R; Wong, B M; Souers, P C

    2008-01-16

    The detailed history of the shock/detonation wave propagation after crossing a room-temperature-room-pressure (RTP) air gap between a 25.4 mm diameter LX-17 donor column and a 25.4 mm diameter by 25.4 mm long LX-17 acceptor pellet is investigated for three different gap widths (3.07, 2.08, and 0.00 mm) using the Embedded Fiber Optic (EFO) technique. The 2.08 mm gap propagated and the 3.07 mm gap failed and this can be seen clearly and unambiguously in the EFO data even though the 25.4 mm-long acceptor pellet would be considered quite short for a determination by more traditional means such as pins.

  11. Performance and Optimization

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

    Performance and Optimization Performance and Optimization Benchmarking Software on Hopper and Carver PURPOSE Test the performance impact of multithreading with representative...

  12. Laser ion source with long pulse width for RHIC-EBIS

    SciTech Connect (OSTI)

    Kondo, K.; Kanesue, T.; Okamura, M.

    2011-03-28

    The Electron Beam Ion Source (EBIS) at Brookhaven National Laboratory is a new heavy ion-projector for RHIC and NASA Space Radiation Laboratory. Laser Ion Source (LIS) with solenoid can supply many kinds of ion from solid targets and is suitable for long pulse length with low current as ion provider for RHIC-EBIS. In order to understand a plasma behavior for fringe field of solenoid, we measure current, pulse width and total ion charges by a new ion probe. The experimental result indicates that the solenoid confines the laser ablation plasma transversely. Laser ion source needs long pulse length with limited current as primary ion provider for RHIC-EBIS. New ion probe can measure current distribution for the radial positions along z axis. The beam pulse length is not effected by magnetic field strength. However, the currents and charges decay with the distance from the end of solenoid. These results indicate that solenoid field has important role for plasma confinement not longitudinally but transversely and solenoid is able to have long pulse length with sufficient total ion charges. Moreover, the results are useful for a design of the extraction system for RHIC-EBIS.

  13. Low mass dark matter and invisible Higgs width in darkon models

    SciTech Connect (OSTI)

    Cai Yi; Ren Bo; He Xiaogang

    2011-04-15

    The Standard Model (SM) plus a real gauge-singlet scalar field dubbed darkon (SM+D) is the simplest model possessing a weakly interacting massive particle (WIMP) dark matter candidate. In this model, the parameters are constrained from dark matter relic density and direct searches. The fact that interaction between darkon and SM particles is only mediated by a Higgs boson exchange may lead to significant modifications to the Higgs boson properties. If the dark matter mass is smaller than half of the Higgs boson mass, then a Higgs boson can decay into a pair of darkons resulting in a large invisible branching ratio. The Higgs boson will be searched for at the LHC and may well be discovered in the near future. If a Higgs boson with a small invisible decay width will be found, the SM+D model with small dark matter mass will be in trouble. We find that by extending the SM+D to a two Higgs doublet model plus a darkon (THDM+D) it is possible to have a Higgs boson with a small invisible branching ratio and at the same time the dark matter can have a low mass. We also comment on other implications of this model.

  14. Band-gap and band-edge engineering of multicomponent garnet scintillators from first principles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yadav, Satyesh K.; Uberuaga, Blas P.; Nikl, Martin; Jiang, Chao; Stanek, Christopher R.

    2015-11-24

    Complex doping schemes in R3Al5O12 (where R is the rare-earth element) garnet compounds have recently led to pronounced improvements in scintillator performance. Specifically, by admixing lutetium and yttrium aluminate garnets with gallium and gadolinium, the band gap is altered in a manner that facilitates the removal of deleterious electron trapping associated with cation antisite defects. Here, we expand upon this initial work to systematically investigate the effect of substitutional admixing on the energy levels of band edges. Density-functional theory and hybrid density-functional theory (HDFT) are used to survey potential admixing candidates that modify either the conduction-band minimum (CBM) or valence-bandmore » maximum (VBM). We consider two sets of compositions based on Lu3B5O12 where B is Al, Ga, In, As, and Sb, and R3Al5O12, where R is Lu, Gd, Dy, and Er. We find that admixing with various R cations does not appreciably affect the band gap or band edges. In contrast, substituting Al with cations of dissimilar ionic radii has a profound impact on the band structure. We further show that certain dopants can be used to selectively modify only the CBM or the VBM. Specifically, Ga and In decrease the band gap by lowering the CBM, while As and Sb decrease the band gap by raising the VBM, the relative change in band gap is quantitatively validated by HDFT. These results demonstrate a powerful approach to quickly screen the impact of dopants on the electronic structure of scintillator compounds, identifying those dopants which alter the band edges in very specific ways to eliminate both electron and hole traps responsible for performance limitations. Furthermore, this approach should be broadly applicable for the optimization of electronic and optical performance for a wide range of compounds by tuning the VBM and CBM.« less

  15. Fundamentals of a modified model of the distribution of neutron-resonance widths and results of its application in the mass-number range of 35 {<=} A {<=} 249

    SciTech Connect (OSTI)

    Sukhovoj, A. M. Khitrov, V. A.

    2013-01-15

    A modified model is developed for describing the distribution of random resonance width for any nuclei. The model assumes the coexistence in a nucleus of one or several partial radiative and neutron amplitudes for respective resonance widths, these amplitudes differing in their parameters. Also, it is assumed that amplitude can be described by a Gaussian curve characterized by a nonzero mean value and a variance not equal to unity and that their most probable values can be obtained with the highest reliability from approximations of cumulative sums of respective widths. An analysis of data for 157 sets of neutron widths for 0 {<=} l {<=} 3 and for 56 sets of total radiative widths has been performed to date. The basic result of this analysis is the following: both for neutron and for total radiative widths, the experimental set of resonance width can be represented with a rather high probability in the form of a superposition of k {<=} 4 types differing in mean amplitude parameters.

  16. Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting

    DOE Patents [OSTI]

    Williamson, Rodney L.; Zanner, Frank J.; Grose, Stephen M.

    1998-01-01

    The electrode gap of a VAR is monitored by determining the skewness of a distribution of gap voltage measurements. A decrease in skewness indicates an increase in gap and may be used to control the gap.

  17. Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting

    DOE Patents [OSTI]

    Williamson, R.L.; Zanner, F.J.; Grose, S.M.

    1998-01-13

    The electrode gap of a VAR is monitored by determining the skewness of a distribution of gap voltage measurements. A decrease in skewness indicates an increase in gap and may be used to control the gap. 4 figs.

  18. Closing Gaps in Modeling Multifamily Retrofits | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Closing Gaps in Modeling Multifamily Retrofits Closing Gaps in Modeling Multifamily Retrofits This presentation was delivered at the U.S. Department of Energy Building America Technical Update meeting on April 29-30, 2013, in Denver, Colorado. cq6_closing_gaps_multifamily_dentz.pdf (1.61 MB) More Documents & Publications Critical Question #6: What are the Challenges and Solutions for Modeling Multifamily Buildings? Building America Webinar: Central Multifamily Water Heating Systems -

  19. Pseudogap and Superconducting Gap in High-Temperature Superconductors

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

    Pseudogap and Superconducting Gap in High-Temperature Superconductors Two decades after the discovery of first high temperature superconductors, the microscopic mechanism of high-Tc superconductivity remains elusive. In conventional superconductors, it has been well established that electrons form so-called "Cooper pairs" to give rise to superconductivity. The pair binding manifests itself as an energy gap in many spectroscopic measurements. This energy gap, known as superconducting

  20. Summary of Gaps and Barriers for Implementing Residential Building Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Efficiency Strategies | Department of Energy Gaps and Barriers for Implementing Residential Building Energy Efficiency Strategies Summary of Gaps and Barriers for Implementing Residential Building Energy Efficiency Strategies This report presents the key gaps and barriers to implementing residential energy efficiency strategies in the U.S. market, as identified in sessions at the U.S. Department of Energy's Building America 2010 Residential Energy Efficiency Meeting held in Denver, Colorado,

  1. Sensitivity Analysis of the Gap Heat Transfer Model in BISON.

    SciTech Connect (OSTI)

    Swiler, Laura Painton; Schmidt, Rodney C.; Williamson, Richard; Perez, Danielle

    2014-10-01

    This report summarizes the result of a NEAMS project focused on sensitivity analysis of the heat transfer model in the gap between the fuel rod and the cladding used in the BISON fuel performance code of Idaho National Laboratory. Using the gap heat transfer models in BISON, the sensitivity of the modeling parameters and the associated responses is investigated. The study results in a quantitative assessment of the role of various parameters in the analysis of gap heat transfer in nuclear fuel.

  2. Measurements of the top quark mass and decay width with the D0 detector

    SciTech Connect (OSTI)

    Ilchenko, Yuriy

    2011-11-01

    The top quark discovery in 1995 at Fermilab is one of the major proofs of the standard model (SM). Due to its unique place in SM, the top quark is an important particle for testing the theory and probing for new physics. This article presents most recent measurements of top quark properties from the D0 detector. In particular, the measurement of the top quark mass, the top antitop mass difference and the top quark decay width. The discovery of the top quark in 1995 confirmed the existence of a third generation of quarks predicted in the standard model (SM). Being the heaviest elementary particle known, the top quark appears to become an important particle in our understanding of the standard model and physics beyond it. Because of its large mass the top quark has a very short lifetime, much shorter than the hadronization time. The predicted lifetime is only 3.3 {center_dot} 10{sup -25}s. Top quark is the only quark whose properties can be studied in isolation. A Lorentz-invariant local Quantum Field Theory, the standard model is expected to conserve CP. Due to its unique properties, the top quark provides a perfect test of CPT invariance in the standard model. An ability to look at the quark before being hadronized allows to measure directly mass of the top quark and its antiquark. An observation of a mass difference between particle and antiparticle would indicate violation of CPT invariance. Top quark through its radiative loop correction to the W mass constrains the mass of the Higgs boson. A precise measurement of the top quark mass provides useful information to the search of Higgs boson by constraining its region of possible masses. Another interesting aspect is that the top quark's Yukawa coupling to the Higgs boson is very close to unity (0.996 {+-} 0.006). That implies it may play a special role in the electroweak symmetry breaking mechanism.

  3. GAPS Power Infrastructure Pvt Ltd | Open Energy Information

    Open Energy Info (EERE)

    Pvt Ltd Jump to: navigation, search Name: GAPS Power & Infrastructure Pvt Ltd. Place: Mumbai, Maharashtra, India Zip: 400098 Sector: Biomass Product: Mumbai-based biomass project...

  4. FAQS Gap Analysis Qualification Card – Environmental Restoration

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  5. FAQS Gap Analysis Qualification Card – Nuclear Explosive Safety Study

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  6. FAQS Gap Analysis Qualification Card – Facility Representative

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  7. FAQS Gap Analysis Qualification Card – Senior Technical Safety Manager

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  8. FAQS Gap Analysis Qualification Card – Criticality Safety

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  9. Catalysis by Design: Bridging the Gap Between Theory and Experiments...

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

    Catalysis by Design: Bridging the Gap between Theory and Experiments Catalyst by Design - Theoretical, Nanostructural, and Experimental Studies of Oxidation Catalyst for Diesel ...

  10. FAQS Gap Analysis Qualification Card – Radiation Protection

    Office of Energy Efficiency and Renewable Energy (EERE)

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  11. FAQS Gap Analysis Qualification Card – Civil Structural Engineering

    Office of Energy Efficiency and Renewable Energy (EERE)

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  12. FAQS Gap Analysis Qualification Card – Construction Management

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  13. Info-Gap Analysis of Truncation Errors in Numerical Simulations...

    Office of Scientific and Technical Information (OSTI)

    Title: Info-Gap Analysis of Truncation Errors in Numerical Simulations. Authors: Kamm, James R. ; Witkowski, Walter R. ; Rider, William J. ; Trucano, Timothy Guy ; Ben-Haim, Yakov. ...

  14. Info-Gap Analysis of Numerical Truncation Errors. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Info-Gap Analysis of Numerical Truncation Errors. Authors: Kamm, James R. ; Witkowski, Walter R. ; Rider, William J. ; Trucano, Timothy Guy ; Ben-Haim, Yakov. Publication ...

  15. Catalysis by Design: Bridging the Gap between Theory and Experiments...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    between Theory and Experiments Catalysis by Design: Bridging the Gap between Theory and Experiments Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research ...

  16. FAQS Gap Analysis Qualification Card – Mechanical Systems

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  17. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic...

  18. FAQS Gap Analysis Qualification Card – Fire Protection Engineering

    Office of Energy Efficiency and Renewable Energy (EERE)

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  19. Minority Serving Institutions (MSIs): Bridging the Gap between...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    More Documents & Publications Bridging the Gap Between Federal Agencies and MSIs Research and Services at the Alabama A&M University Research Institute Office of Energy Efficiency ...

  20. FAQS Gap Analysis Qualification Card – General Technical Base

    Broader source: Energy.gov [DOE]

    Functional Area Qualification Standard Gap Analysis Qualification Cards outline the differences between the last and latest version of the FAQ Standard.

  1. Metallic photonic band-gap materials

    SciTech Connect (OSTI)

    Sigalas, M.M.; Chan, C.T.; Ho, K.M.; Soukoulis, C.M.

    1995-10-15

    We calculate the transmission and absorption of electromagnetic waves propagating in two-dimensional (2D) and 3D periodic metallic photonic band-gap (PBG) structures. For 2D systems, there is substantial difference between the {ital s}- and {ital p}-polarized waves. The {ital p}-polarized waves exhibit behavior similar to the dielectric PBG`s. But, the {ital s}-polarized waves have a cutoff frequency below which there are no propagating modes. For 3D systems, the results are qualitatively the same for both polarizations but there are important differences related to the topology of the structure. For 3D structures with isolated metallic scatterers (cermet topology), the behavior is similar to that of the dielectric PBG`s, while for 3D structures with the metal forming a continuous network (network topology), there is a cutoff frequency below which there are no propagating modes. The systems with the network topology may have some interesting applications for frequencies less than about 1 THz where the absorption can be neglected. We also study the role of the defects in the metallic structures.

  2. Heuristic Drift-based Model of the Power Scrape-off width in H-mode Tokamaks

    SciTech Connect (OSTI)

    Robert J. Goldston

    2011-04-29

    An heuristic model for the plasma scrape-off width in H-mode plasmas is introduced. Grad B and curv B drifts into the SOL are balanced against sonic parallel flows out of the SOL, to the divertor plates. The overall particle flow pattern posited is a modification for open field lines of Pfirsch-Shlter flows to include sinks to the divertors. These assumptions result in an estimated SOL width of ~ 2a?p/R. They also result in a first-principles calculation of the particle confinement time of H-mode plasmas, qualitatively consistent with experimental observations. It is next assumed that anomalous perpendicular electron thermal diffusivity is the dominant source of heat flux across the separatrix, investing the SOL width, defined above, with heat from the main plasma. The separatrix temperature is calculated based on a two-point model balancing power input to the SOL with Spitzer-Hrm parallel thermal conduction losses to the divertor. This results in a heuristic closed-form prediction for the power scrape-off width that is in reasonable quantitative agreement both in absolute magnitude and in scaling with recent experimental data from deuterium plasmas. Further work should include full numerical calculations, including all magnetic and electric drifts, as well as more thorough comparison with experimental data.

  3. An investigation into factors affecting the precision of CT radiation dose profile width measurements using radiochromic films

    SciTech Connect (OSTI)

    Li, Baojun Behrman, Richard H.

    2015-04-15

    Purpose: To investigate the impact of x-ray beam energy, exposure intensity, and flat-bed scanner uniformity and spatial resolution on the precision of computed tomography (CT) beam width measurements using Gafchromic XR-QA2 film and an off-the-shelf document scanner. Methods: Small strips of Gafchromic film were placed at isocenter in a CT scanner and exposed at various x-ray beam energies (80–140 kVp), exposure levels (50–400 mA s), and nominal beam widths (1.25, 5, and 10 mm). The films were scanned in reflection mode on a Ricoh MP3501 flat-bed document scanner using several spatial resolution settings (100 to 400 dpi) and at different locations on the scanner bed. Reflection measurements were captured in digital image files and radiation dose profiles generated by converting the image pixel values to air kerma through film calibration. Beam widths were characterized by full width at half maximum (FWHM) and full width at tenth maximum (FWTM) of dose profiles. Dependences of these parameters on the above factors were quantified in percentage change from the baselines. Results: The uncertainties in both FWHM and FWTM caused by varying beam energy, exposure level, and scanner uniformity were all within 4.5% and 7.6%, respectively. Increasing scanner spatial resolution significantly increased the uncertainty in both FWHM and FWTM, with FWTM affected by almost 8 times more than FWHM (48.7% vs 6.5%). When uncalibrated dose profiles were used, FWHM and FWTM were over-estimated by 11.6% and 7.6%, respectively. Narrower beam width appeared more sensitive to the film calibration than the wider ones (R{sup 2} = 0.68 and 0.85 for FWHM and FWTM, respectively). The global and maximum local background variations of the document scanner were 1.2%. The intrinsic film nonuniformity for an unexposed film was 0.3%. Conclusions: Measurement of CT beam widths using Gafchromic XR-QA2 films is robust against x-ray energy, exposure level, and scanner uniformity. With proper film

  4. Aristos Optimization Package

    Energy Science and Technology Software Center (OSTI)

    2007-03-01

    Aristos is a Trilinos package for nonlinear continuous optimization, based on full-space sequential quadratic programming (SQP) methods. Aristos is specifically designed for the solution of large-scale constrained optimization problems in which the linearized constraint equations require iterative (i.e. inexact) linear solver techniques. Aristos' unique feature is an efficient handling of inexactness in linear system solves. Aristos currently supports the solution of equality-constrained convex and nonconvex optimization problems. It has been used successfully in the areamore » of PDE-constrained optimization, for the solution of nonlinear optimal control, optimal design, and inverse problems.« less

  5. Regenerator optimization for Stirling cycle refrigeration II

    SciTech Connect (OSTI)

    Colgate, S.A.; Petschek, A.G.

    1994-07-01

    A cryogenic regenerator for a Stirling cycle is discussed using fractional loss or entropy gain as the criterion of performance. The gas losses are treated separately from heat storage medium losses. We argue that the optimum design corresponds to uniform channel flow with minimum turbulence where the gas velocity and channel width are optimized as a function of gas temperature. The maximization of heat transfer from the gas to the wall and the minimization of entropy production by friction leads to a gas flow velocity equal to sound speed times loss fraction, 1/{sigma}. This velocity and an axial thermal conductivity in the gas leads to a minimum channel width and characteristic length, L=T(dz/dT). A particular scaling of width, W{sup 2} = W{sub o}{sup 2}T{sup 1/2}, and length, L = L{sub o} T{sup {minus}1/2} leads to a design where longitudinal conduction decreases as T{sup 3/2} and the remaining two losses, transverse conduction and friction are equal and constant. The loss fraction, 1/{sigma}, must be made quite small, {approximately}(1/60) in order that the cumulative losses for a large temperature ratio like 300K to 4K, be small enough, like 20% to 40%. This is because half the entropy generated as a loss must be transported first to the cold end before returning to the hot end before being rejected. The dead volume ratio then determines the minimum frequency and with it and the pressure the necessary wall properties. The thermal properties of the channel wall must then accommodate this cyclic heat flow without substantially increasing the loss fraction. This generation of entropy in the walls is derived in terms of the wall heat capacity and thermal conductivity.

  6. Physics of band-gap formation and its evolution in the pillar-based phononic crystal structures

    SciTech Connect (OSTI)

    Pourabolghasem, Reza; Mohammadi, Saeed; Eftekhar, Ali Asghar; Adibi, Ali; Khelif, Abdelkrim

    2014-07-07

    In this paper, the interplay of Bragg scattering and local resonance is theoretically studied in a phononic crystal (PnC) structure composed of a silicon membrane with periodic tungsten pillars. The comparison of phononic band gaps (PnBGs) in three different lattice types (i.e., square, triangular, and honeycomb) with different pillar geometries shows that different PnBGs have varying degrees of dependency on the lattice symmetry based on the interplay of the local resonances and the Bragg effect. The details of this interplay is discussed. The significance of locally resonating pillars, specially in the case of tall pillars, on PnBGs is discussed and verified by examining the PnBG position and width in perturbed lattices via Monte Carlo simulations. It is shown that the PnBGs caused by the local resonance of the pillars are more resilient to the lattice perturbations than those caused by Bragg scattering.

  7. Tuning the band structures of a one-dimensional width-modulated magnonic crystal by a transverse magnetic field

    SciTech Connect (OSTI)

    Di, K.; Lim, H. S. Zhang, V. L.; Ng, S. C.; Kuok, M. H.; Nguyen, H. T.; Cottam, M. G.

    2014-02-07

    Theoretical studies, based on three independent techniques, of the band structure of a one-dimensional width-modulated magnonic crystal under a transverse magnetic field are reported. The band diagram is found to display distinct behaviors when the transverse field is either larger or smaller than a critical value. The widths and center positions of bandgaps exhibit unusual non-monotonic and large field-tunability through tilting the direction of magnetization. Some bandgaps can be dynamically switched on and off by simply tuning the strength of such a static field. Finally, the impact of the lowered symmetry of the magnetic ground state on the spin-wave excitation efficiency of an oscillating magnetic field is discussed. Our finding reveals that the magnetization direction plays an important role in tailoring magnonic band structures and hence in the design of dynamic spin-wave switches.

  8. Bounding the Higgs width at the LHC using full analytic results for $$gg → e^- e^+ \\mu^- \\mu^+$$

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Campbell, John M.; Ellis, R. Keith; Williams, Ciaran

    2014-04-09

    We revisit the hadronic production of the four-lepton final state, e– e+ μ– μ+, through the fusion of initial state gluons. This process is mediated by loops of quarks and we provide first full analytic results for helicity amplitudes that account for both the effects of the quark mass in the loop and off-shell vector bosons. The analytic results have been implemented in the Monte Carlo program MCFM and are both fast, and numerically stable in the region of low Z transverse momentum. We use our results to study the interference between Higgs-mediated and continuum production of four-lepton final states,more » which is necessary in order to obtain accurate theoretical predictions outside the Higgs resonance region. We have confirmed and extended a recent analysis of Caola and Melnikov that proposes to use a measurement of the off-shell region to constrain the total width of the Higgs boson. Using a simple cut-and-count method, existing LHC data should bound the width at the level of 25-45 times the Standard Model expectation. We investigate the power of using a matrix element method to construct a kinematic discriminant to sharpen the constraint. Furthermore, in our analysis the bound on the Higgs width is improved by a factor of about 1.6 using a simple cut on the MEM discriminant, compared to an invariant mass cut μ4l > 300 GeV.« less

  9. Filling Knowledge Gaps with Five Fuel Cycle Studies

    SciTech Connect (OSTI)

    Steven J. Piet; Jess Gehin; William Halsey; Temitope Taiwo

    2010-11-01

    During FY 2010, five studies were conducted of technology families’ applicability to various fuel cycle strategies to fill in knowledge gaps in option space and to better understand trends and patterns. Here, a “technology family” is considered to be defined by a type of reactor and by selection of which actinides provide fuel. This report summarizes the higher-level findings; the detailed analyses and results are documented in five individual reports, as follows: • Advanced once through with uranium fuel in fast reactors (SFR), • Advanced once through (uranium fuel) or single recycle (TRU fuel) in high temperature gas cooled reactors (HTGR), • Sustained recycle with Th/U-233 in light water reactors (LWRs), • Sustained recycle with Th/U-233 in molten salt reactors (MSR), and • Several fuel cycle missions with Fusion-Fission Hybrid (FFH). Each study examined how the designated technology family could serve one or more designated fuel cycle missions, filling in gaps in overall option space. Each study contains one or more illustrative cases that show how the technology family could be used to meet a fuel cycle mission, as well as broader information on the technology family such as other potential fuel cycle missions for which insufficient information was available to include with an illustrative case. None of the illustrative cases can be considered as a reference, baseline, or nominal set of parameters for judging performance; the assessments were designed to assess areas of option space and were not meant to be optimized. There is no implication that any of the cases or technology families are necessarily the best way to meet a given fuel cycle mission. The studies provide five examples of 1-year fuel cycle assessments of technology families. There is reasonable coverage in the five studies of the performance areas of waste management and uranium utilization. The coverage of economics, safety, and proliferation resistance and physical protection in

  10. To Bridge LEDs' Green Gap, Scientists Think Small

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

    To Bridge LEDs' Green Gap, Scientists Think Small To Bridge LEDs' Green Gap, Scientists Think Small Nanostructures Half a DNA Strand-Wide Show Promise for Efficient LEDs April 4, 2014 Contact: Margie Wylie, mwylie@lbl.gov, +1 510 486 7421 Nanostructures half the breadth of a DNA strand could improve the efficiency of light emitting diodes (LEDs), especially in the "green gap," a portion of the spectrum where LED efficiency plunges, simulations at the U.S. Department of Energy's

  11. Integrated controls design optimization

    SciTech Connect (OSTI)

    Lou, Xinsheng; Neuschaefer, Carl H.

    2015-09-01

    A control system (207) for optimizing a chemical looping process of a power plant includes an optimizer (420), an income algorithm (230) and a cost algorithm (225) and a chemical looping process models. The process models are used to predict the process outputs from process input variables. Some of the process in puts and output variables are related to the income of the plant; and some others are related to the cost of the plant operations. The income algorithm (230) provides an income input to the optimizer (420) based on a plurality of input parameters (215) of the power plant. The cost algorithm (225) provides a cost input to the optimizer (420) based on a plurality of output parameters (220) of the power plant. The optimizer (420) determines an optimized operating parameter solution based on at least one of the income input and the cost input, and supplies the optimized operating parameter solution to the power plant.

  12. Enhanced Superconducting Gaps in Trilayer High-Temperature Bi...

    Office of Scientific and Technical Information (OSTI)

    ...-Temperature Bi (2) Sr (2) Ca (2) Cu (3) O (10+delta) Cuprate Superconductor Citation Details In-Document Search Title: Enhanced Superconducting Gaps in Trilayer High-Temperature ...

  13. Interface Ferroelectric Transition near the Gap-Opening Temperature...

    Office of Scientific and Technical Information (OSTI)

    Interface Ferroelectric Transition near the Gap-Opening Temperature in a Single-Unit-Cell FeSe Film Grown on Nb-DopedSrTiO3Substrate Citation Details In-Document Search This...

  14. Permanent-magnet-less machine having an enclosed air gap

    DOE Patents [OSTI]

    Hsu, John S.

    2013-03-05

    A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

  15. Permanent-magnet-less machine having an enclosed air gap

    DOE Patents [OSTI]

    Hsu, John S.

    2012-02-07

    A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

  16. Proper Sustainability: GAP Grant Proposal Work Plan Strategy Webinar

    Broader source: Energy.gov [DOE]

    In this webinar I will discuss the new GAP grant requirements for tribal environmental programs and strategies for crafting a work plan that focuses on capacity building activities.  My goal is to...

  17. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

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

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Wednesday, 26 March 2008 00:00 Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest

  18. Bridging the Gap between Fundamental Physics and Chemistry and Applied

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Models for HCCI Engines | Department of Energy Bridging the Gap between Fundamental Physics and Chemistry and Applied Models for HCCI Engines Bridging the Gap between Fundamental Physics and Chemistry and Applied Models for HCCI Engines 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_assanis.pdf (1.42 MB) More Documents & Publications Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines Modeling of HCCI and PCCI

  19. Method for Creating Photonic Band Gap Materials - Energy Innovation Portal

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

    Method for Creating Photonic Band Gap Materials Ames Laboratory Contact AMES About This Technology Technology Marketing Summary Innovative microstructures that can direct light in a manner similar to the way semiconductors can influence electrons can be produced by creating what is termed a photonic band gap. These microstructures have the potential to change the way optoelectronic devices, such as photodiodes, LEDs, and integrated optical circuit elements, are designed and used. Ames Laboratory

  20. Computation of radiative heat transport across a nanoscale vacuum gap

    SciTech Connect (OSTI)

    Budaev, Bair V. Bogy, David B.

    2014-02-10

    Radiation heat transport across a vacuum gap between two half-spaces is studied. By consistently applying only the fundamental laws of physics, we obtain an algebraic equation that connects the temperatures of the half-spaces and the heat flux between them. The heat transport coefficient generated by this equation for such structures matches available experimental data for nanoscale and larger gaps without appealing to any additional specific mechanisms of energy transfer.

  1. CHP: Connecting the Gap between Markets and Utility Interconnection and

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Tariff Practices, 2006 | Department of Energy Connecting the Gap between Markets and Utility Interconnection and Tariff Practices, 2006 CHP: Connecting the Gap between Markets and Utility Interconnection and Tariff Practices, 2006 The adoption of combined heat and power (CHP) systems by American industries has made substantial strides in the last few years. The purpose of this report is threefold: one, to expose still existent barriers to entry for proposed CHP facilities; secondarily, to

  2. Hydrogeologic Model for the Gable Gap Area, Hanford Site

    SciTech Connect (OSTI)

    Bjornstad, Bruce N.; Thorne, Paul D.; Williams, Bruce A.; Last, George V.; Thomas, Gregory S.; Thompson, Michael D.; Ludwig, Jami L.; Lanigan, David C.

    2010-09-30

    Gable Gap is a structural and topographic depression between Gable Mountain and Gable Butte within the central Hanford Site. It has a long and complex geologic history, which includes tectonic uplift synchronous with erosional downcutting associated with the ancestral Columbia River during both Ringold and Cold Creek periods, and by the later Ice Age (mostly glacial Lake Missoula) floods. The gap was subsequently buried and partially backfilled by mostly coarse-grained, Ice Age flood deposits (Hanford formation). Erosional remnants of both the Ringold Formation and Cold Creek unit locally underlie the high-energy flood deposits. A large window exists in the gap where confined basalt aquifers are in contact with the unconfined suprabasalt aquifer. Several paleochannels, of both Hanford and Ringold Formation age, were eroded into the basalt bedrock across Gable Gap. Groundwater from the Central Plateau presently moves through Gable Gap via one or more of these shallow paleochannels. As groundwater levels continue to decline in the region, groundwater flow may eventually be cut off through Gable Gap.

  3. Energy optimization system

    DOE Patents [OSTI]

    Zhou, Zhi; de Bedout, Juan Manuel; Kern, John Michael; Biyik, Emrah; Chandra, Ramu Sharat

    2013-01-22

    A system for optimizing customer utility usage in a utility network of customer sites, each having one or more utility devices, where customer site is communicated between each of the customer sites and an optimization server having software for optimizing customer utility usage over one or more networks, including private and public networks. A customer site model for each of the customer sites is generated based upon the customer site information, and the customer utility usage is optimized based upon the customer site information and the customer site model. The optimization server can be hosted by an external source or within the customer site. In addition, the optimization processing can be partitioned between the customer site and an external source.

  4. Momentum dependence of the superconducting gap and in-gap states in MgB2 multiband superconductor

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mou, Daixiang; Jiang, Rui; Taufour, Valentin; Bud'ko, S. L.; Canfield, P. C.; Kaminski, Adam

    2015-06-29

    We use tunable laser-based angle-resolved photoemission spectroscopy to study the electronic structure of the multiband superconductor MgB2. These results form the baseline for detailed studies of superconductivity in multiband systems. We find that the magnitude of the superconducting gap on both σ bands follows a BCS-like variation with temperature with Δ0 ~ 7meV. Furthermore, the value of the gap is isotropic within experimental uncertainty and in agreement with a pure s-wave pairing symmetry. We observe in-gap states confined to kF of the σ band that occur at some locations of the sample surface. As a result, the energy of thismore » excitation, ~ 3 meV, was found to be somewhat larger than the previously reported gap on π Fermi sheet and therefore we cannot exclude the possibility of interband scattering as its origin.« less

  5. NETL: Gasifier Optimization

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

    gasifier optimization The Gasifier Optimization and Plant Supporting Systems key technology area focuses on improving the performance and reducing the costs of advanced gasifiers. Specifically, current projects focus on creating models to better understand the kinetics and particulate behavior of fuel inside a gasifier. This work supports development of a highly advanced gasifier optimally configured with its supporting systems, which would incorporate the most aggressive and successful

  6. Spearmint - Bayesian Hyperparameter Optimization

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

    Optimization » Spearmint Spearmint - Bayesian Hyperparameter Optimization Spearmint is a Python Bayesian optimization codebase. Using Spearmint module load spearmint spearmint -c path/to/config.json config.json must have the following form: { "language" : "PYTHON", "experiment-name" : "any name you want", "polling-time" : 1, "resources" : { "my-machine" : { "scheduler" : "local", "max-concurrent"

  7. Hopper Performance and Optimization

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

    Performance and Optimization Compiler Comparisons Comparison of different compilers with different options on several benchmarks. Read More Using OpenMP Effectively...

  8. Control and optimization system

    DOE Patents [OSTI]

    Xinsheng, Lou

    2013-02-12

    A system for optimizing a power plant includes a chemical loop having an input for receiving an input parameter (270) and an output for outputting an output parameter (280), a control system operably connected to the chemical loop and having a multiple controller part (230) comprising a model-free controller. The control system receives the output parameter (280), optimizes the input parameter (270) based on the received output parameter (280), and outputs an optimized input parameter (270) to the input of the chemical loop to control a process of the chemical loop in an optimized manner.

  9. Optimizing Data Transfer Nodes

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

    Optimizing Data Transfer Nodes using Packet Pacing Nathan Hanford University of California ... An important performance problem that we foresee with Data Transfer Nodes (DTNs) in the ...

  10. Optimize Parallel Pumping Systems

    Broader source: Energy.gov [DOE]

    This tip sheet describes how to optimize the performance of multiple pumps operating continuously as part of a parallel pumping system.

  11. Bounding the Higgs width at the LHC using full analytic results for $gg → e^- e^+ \\mu^- \\mu^+$

    SciTech Connect (OSTI)

    Campbell, John M.; Ellis, R. Keith; Williams, Ciaran

    2014-04-09

    We revisit the hadronic production of the four-lepton final state, e e+ μ μ+, through the fusion of initial state gluons. This process is mediated by loops of quarks and we provide first full analytic results for helicity amplitudes that account for both the effects of the quark mass in the loop and off-shell vector bosons. The analytic results have been implemented in the Monte Carlo program MCFM and are both fast, and numerically stable in the region of low Z transverse momentum. We use our results to study the interference between Higgs-mediated and continuum production of four-lepton final states, which is necessary in order to obtain accurate theoretical predictions outside the Higgs resonance region. We have confirmed and extended a recent analysis of Caola and Melnikov that proposes to use a measurement of the off-shell region to constrain the total width of the Higgs boson. Using a simple cut-and-count method, existing LHC data should bound the width at the level of 25-45 times the Standard Model expectation. We investigate the power of using a matrix element method to construct a kinematic discriminant to sharpen the constraint. Furthermore, in our analysis the bound on the Higgs width is improved by a factor of about 1.6 using a simple cut on the MEM discriminant, compared to an invariant mass cut μ4l > 300 GeV.

  12. Performance and Optimization

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

    Optimization Performance and Optimization Running Jobs Efficiently This page defines job efficiency and how to measure the efficiency of your jobs. Read More » PDSF IO Monitoring Plots of continuous IO monitoring for the eliza file systems and project. Read More » Last edited: 2016-04-29 11:35:20

  13. Modeling the effect of lithium-induced pedestal profiles on scrape-off-layer turbulence and the heat flux width

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Russell, David A.; D'Ippolito, Daniel A.; Myra, James R.; Canik, John M.; Gray, Travis K.; Zweben, Stewart J.

    2015-09-01

    The effect of lithium (Li) wall coatings on scrape-off-layer (SOL) turbulence in the National Spherical Torus Experiment (NSTX) is modeled with the Lodestar SOLT (“SOL Turbulence”) code. Specifically, the implications for the SOL heat flux width of experimentally observed, Li-induced changes in the pedestal profiles are considered. The SOLT code used in the modeling has been expanded recently to include ion temperature evolution and ion diamagnetic drift effects. This work focuses on two NSTX discharges occurring pre- and with-Li deposition. The simulation density and temperature profiles are constrained, inside the last closed flux surface only, to match those measured inmore » the two experiments, and the resulting drift-interchange-driven turbulence is explored. The effect of Li enters the simulation only through the pedestal profile constraint: Li modifies the experimental density and temperature profiles in the pedestal, and these profiles affect the simulated SOL turbulence. The power entering the SOL measured in the experiments is matched in the simulations by adjusting “free” dissipation parameters (e.g., diffusion coefficients) that are not measured directly in the experiments. With power-matching, (a) the heat flux SOL width is smaller, as observed experimentally by infra-red thermography, and (b) the simulated density fluctuation amplitudes are reduced with Li, as inferred for the experiments as well from reflectometry analysis. The instabilities and saturation mechanisms that underlie the SOLT model equilibria are also discussed.« less

  14. Complete Feshbach-type calculations of energy positions and widths of autoionizing states in Li-like atoms

    SciTech Connect (OSTI)

    Cardona, Juan Carlos; Sanz-Vicario, Jose Luis; Martin, Fernando

    2010-08-15

    Applications of the Feshbach formalism to systems of more than two active electrons are very scarce due to practical limitations in the construction of the projection operators P and Q that are inherent to the theory. As a consequence, most previous applications rely on the use of approximate quasiprojection operators, whose theoretical justification is not yet clear. In this work, an implementation of the Feshbach formalism for three-electron atoms is presented that includes all the ingredients of the original formalism. Energy positions and autoionization widths of the lowest {sup 2}S{sup e}, {sup 2}P{sup o}, and {sup 2}D{sup e} autoionizing states of Li and Ne{sup 7+} have been evaluated. The results show that the use of quasiprojection operators is justified for the evaluation of resonant positions. However, for the {sup 2}S{sup e} states of Li, the use of quasiprojection operators can lead to errors in the autoionization widths of the order of 100%.

  15. Modeling the effect of lithium-induced pedestal profiles on scrape-off-layer turbulence and the heat flux width

    SciTech Connect (OSTI)

    Russell, David A.; D'Ippolito, Daniel A.; Myra, James R.; Canik, John M.; Gray, Travis K.; Zweben, Stewart J.

    2015-09-01

    The effect of lithium (Li) wall coatings on scrape-off-layer (SOL) turbulence in the National Spherical Torus Experiment (NSTX) is modeled with the Lodestar SOLT (“SOL Turbulence”) code. Specifically, the implications for the SOL heat flux width of experimentally observed, Li-induced changes in the pedestal profiles are considered. The SOLT code used in the modeling has been expanded recently to include ion temperature evolution and ion diamagnetic drift effects. This work focuses on two NSTX discharges occurring pre- and with-Li deposition. The simulation density and temperature profiles are constrained, inside the last closed flux surface only, to match those measured in the two experiments, and the resulting drift-interchange-driven turbulence is explored. The effect of Li enters the simulation only through the pedestal profile constraint: Li modifies the experimental density and temperature profiles in the pedestal, and these profiles affect the simulated SOL turbulence. The power entering the SOL measured in the experiments is matched in the simulations by adjusting “free” dissipation parameters (e.g., diffusion coefficients) that are not measured directly in the experiments. With power-matching, (a) the heat flux SOL width is smaller, as observed experimentally by infra-red thermography, and (b) the simulated density fluctuation amplitudes are reduced with Li, as inferred for the experiments as well from reflectometry analysis. The instabilities and saturation mechanisms that underlie the SOLT model equilibria are also discussed.

  16. Low temperature synthesis of Ru–Cu alloy nanoparticles with the compositions in the miscibility gap

    SciTech Connect (OSTI)

    Martynova, S.A.; Filatov, E.Yu.; Korenev, S.V.; Kuratieva, N.V.; Sheludyakova, L.A.; Plusnin, P.E.; Shubin, Yu.V.; Slavinskaya, E.M.; Boronin, A.I.

    2014-04-01

    A complex salt [Ru(NH{sub 3}){sub 5}Cl][Cu(C{sub 2}O{sub 4}){sub 2}H{sub 2}O]—the precursor of nanoalloys combining ruthenium and copper was prepared. It crystallizes in the monoclinic space group P2{sub 1}/n. Thermal properties of the prepared salt were examined in different atmospheres (helium, hydrogen, oxygen). Thermal decomposition of the precursor in inert atmosphere was thoroughly examined and the intermediate products were characterized. Experimental conditions for preparation of copper-rich (up to 12 at% of copper) metastable solid solution Cu{sub x}Ru{sub 1−x} (based on Ru structure) were optimized, what is in sharp contrast to the bimetallic miscibility gap known for the bulk counterparts in a wide composition range. Catalytic properties of copper–ruthenium oxide composite were tested in catalytic oxidation of CO. - Highlights: • We synthesized new precursor of CuRu metastable nanoalloys. • Thermal properties of the prepared salt were examined in different atmospheres. • Thermodestruction mechanism of precursor are studied. • Cu{sub 0.12}Ru{sub 0.88} nanoalloy with the compositions in the miscibility gap is obtained. • Catalytic conversion of CO on copper–ruthenium oxide composite were examined.

  17. Band gap engineering strategy via polarization rotation in perovskite ferroelectrics

    SciTech Connect (OSTI)

    Wang, Fenggong Grinberg, Ilya; Rappe, Andrew M.

    2014-04-14

    We propose a strategy to engineer the band gaps of perovskite oxide ferroelectrics, supported by first principles calculations. We find that the band gaps of perovskites can be substantially reduced by as much as 1.2 eV through local rhombohedral-to-tetragonal structural transition. Furthermore, the strong polarization of the rhombohedral perovskite is largely preserved by its tetragonal counterpart. The B-cation off-center displacements and the resulting enhancement of the antibonding character in the conduction band give rise to the wider band gaps of the rhombohedral perovskites. The correlation between the structure, polarization orientation, and electronic structure lays a good foundation for understanding the physics of more complex perovskite solid solutions and provides a route for the design of photovoltaic perovskite ferroelectrics.

  18. Amorphous copper tungsten oxide with tunable band gaps

    SciTech Connect (OSTI)

    Chen Le; Shet, Sudhakar; Tang Houwen; Wang Heli; Yan Yanfa; Turner, John; Al-Jassim, Mowafak; Ahn, Kwang-soon

    2010-08-15

    We report on the synthesis of amorphous copper tungsten oxide thin films with tunable band gaps. The thin films are synthesized by the magnetron cosputtering method. We find that due to the amorphous nature, the Cu-to-W ratio in the films can be varied without the limit of the solubility (or phase separation) under appropriate conditions. As a result, the band gap and conductivity type of the films can be tuned by controlling the film composition. Unfortunately, the amorphous copper tungsten oxides are not stable in aqueous solution and are not suitable for the application of photoelectrochemical splitting of water. Nonetheless, it provides an alternative approach to search for transition metal oxides with tunable band gaps.

  19. A Fixed Gap APPLE II Undulator for SLS

    SciTech Connect (OSTI)

    Schmidt, T.; Imhof, A.; Ingold, G.; Jakob, B.; Vollenweider, C.

    2007-01-19

    To vary the polarization vector of an APPLE II undulator continuously from 0 - 180 deg., all four magnet arrays need to be movable. Following the adjustable-phase undulator approach by R. Carr, a 3.4 m long fixed gap undulator for SLS with a gap of 11.6 mm has been constructed. It will be installed in fall 2006. The gap drive is replaced by a pair-wise shift of the magnet arrays to change the energy, while the polarization is changed by shifts of diagonal arrays. The high injection efficiency and standard operation top-up mode at the SLS allows this simplified undulator design. The design as well as the operational aspects will be discussed.

  20. NGNP Project Regulatory Gap Analysis for Modular HTGRs

    SciTech Connect (OSTI)

    Wayne Moe

    2011-09-01

    The Next Generation Nuclear Plant (NGNP) Project Regulatory Gap Analysis (RGA) for High Temperature Gas-Cooled Reactors (HTGR) was conducted to evaluate existing regulatory requirements and guidance against the design characteristics specific to a generic modular HTGR. This final report presents results and identifies regulatory gaps concerning current Nuclear Regulatory Commission (NRC) licensing requirements that apply to the modular HTGR design concept. This report contains appendices that highlight important HTGR licensing issues that were found during the RGA study. The information contained in this report will be used to further efforts in reconciling HTGR-related gaps in the NRC licensing structure, which has to date largely focused on light water reactor technology.

  1. GAP Flow Measurements During the Mesoscale Alpine Programme

    SciTech Connect (OSTI)

    Mayr, G.; Armi, L.; Arnold, S.; Banta, Robert M.; Darby, Lisa S.; Durran, D. D.; Flamant, C.; Gabersek, S.; Gohm, A.; Mayr, R.; Mobbs, S.; Nance, L. B.; Vergeiner, I.; Vergeiner, J.; Whiteman, Charles D.

    2004-04-30

    This article provides an overview of the Gap Flow sub-program of the Mesoscale Alpine Programme, a major international meteorological field experiment conducted in the European Alps. The article describes the initial results of an investigation of the wind flow through the Brenner Pass gap in the east-west oriented central section of the European Alps under conditions of south foehn. The overview describes the objectives of the experiments, the instrumentation used for the field investigation, and the mesoscale model simulations. Initial findings of the scientific program are provided.

  2. Special purpose modes in photonic band gap fibers

    DOE Patents [OSTI]

    Spencer, James; Noble, Robert; Campbell, Sara

    2013-04-02

    Photonic band gap fibers are described having one or more defects suitable for the acceleration of electrons or other charged particles. Methods and devices are described for exciting special purpose modes in the defects including laser coupling schemes as well as various fiber designs and components for facilitating excitation of desired modes. Results are also presented showing effects on modes due to modes in other defects within the fiber and due to the proximity of defects to the fiber edge. Techniques and devices are described for controlling electrons within the defect(s). Various applications for electrons or other energetic charged particles produced by such photonic band gap fibers are also described.

  3. Multi-gap high impedance plasma opening switch

    DOE Patents [OSTI]

    Mason, R.J.

    1996-10-22

    A high impedance plasma opening switch having an anode and a cathode and at least one additional electrode placed between the anode and cathode is disclosed. The presence of the additional electrodes leads to the creation of additional plasma gaps which are in series, increasing the net impedance of the switch. An equivalent effect can be obtained by using two or more conventional plasma switches with their plasma gaps wired in series. Higher impedance switches can provide high current and voltage to higher impedance loads such as plasma radiation sources. 12 figs.

  4. Multi-gap high impedance plasma opening switch

    DOE Patents [OSTI]

    Mason, Rodney J.

    1996-01-01

    A high impedance plasma opening switch having an anode and a cathode and at least one additional electrode placed between the anode and cathode. The presence of the additional electrodes leads to the creation of additional plasma gaps which are in series, increasing the net impedance of the switch. An equivalent effect can be obtained by using two or more conventional plasma switches with their plasma gaps wired in series. Higher impedance switches can provide high current and voltage to higher impedance loads such as plasma radiation sources.

  5. Closing the Gender Gap in Energy Policy | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Closing the Gender Gap in Energy Policy Closing the Gender Gap in Energy Policy April 7, 2011 - 3:07pm Addthis Melanie A. Kenderdine Melanie A. Kenderdine Director of the Office of Energy Policy and Systems Analysis What are the key facts? There's not just a shortage of women in technical energy-related fields, there's also a shortage of women in energy policy. Women hold only 27 percent of the science and engineering jobs in the United States. Editor's Note: Join the conversation surrounding

  6. Rapid Optimization Library

    Energy Science and Technology Software Center (OSTI)

    2014-05-13

    ROL provides interfaces to and implementations of algorithms for gradient-based unconstrained and constrained optimization. ROL can be used to optimize the response of any client simulation code that evaluates scalar-valued response functions. If the client code can provide gradient information for the response function, ROL will take advantage of it, resulting in faster runtimes. ROL's interfaces are matrix-free, in other words ROL only uses evaluations of scalar-valued and vector-valued functions. ROL can be used tomore » solve optimal design problems and inverse problems based on a variety of simulation software.« less

  7. TOOLKIT FOR ADVANCED OPTIMIZATION

    Energy Science and Technology Software Center (OSTI)

    2000-10-13

    The TAO project focuses on the development of software for large scale optimization problems. TAO uses an object-oriented design to create a flexible toolkit with strong emphasis on the reuse of external tools where appropriate. Our design enables bi-directional connection to lower level linear algebra support (for example, parallel sparse matrix data structures) as well as higher level application frameworks. The Toolkist for Advanced Optimization (TAO) is aimed at teh solution of large-scale optimization problemsmore » on high-performance architectures. Our main goals are portability, performance, scalable parallelism, and an interface independent of the architecture. TAO is suitable for both single-processor and massively-parallel architectures. The current version of TAO has algorithms for unconstrained and bound-constrained optimization.« less

  8. Library for Nonlinear Optimization

    Energy Science and Technology Software Center (OSTI)

    2001-10-09

    OPT++ is a C++ object-oriented library for nonlinear optimization. This incorporates an improved implementation of an existing capability and two new algorithmic capabilities based on existing journal articles and freely available software.

  9. Parallel Algorithms for Graph Optimization using Tree Decompositions

    SciTech Connect (OSTI)

    Sullivan, Blair D; Weerapurage, Dinesh P; Groer, Christopher S

    2012-06-01

    Although many $\\cal{NP}$-hard graph optimization problems can be solved in polynomial time on graphs of bounded tree-width, the adoption of these techniques into mainstream scientific computation has been limited due to the high memory requirements of the necessary dynamic programming tables and excessive runtimes of sequential implementations. This work addresses both challenges by proposing a set of new parallel algorithms for all steps of a tree decomposition-based approach to solve the maximum weighted independent set problem. A hybrid OpenMP/MPI implementation includes a highly scalable parallel dynamic programming algorithm leveraging the MADNESS task-based runtime, and computational results demonstrate scaling. This work enables a significant expansion of the scale of graphs on which exact solutions to maximum weighted independent set can be obtained, and forms a framework for solving additional graph optimization problems with similar techniques.

  10. 2009 Voluntary Protection Programs Participants' Association (VPPPA) Presentation: Gaps in your Safety Program?

    Broader source: Energy.gov [DOE]

    2009 Voluntary Protection Programs Participants' Association (VPPPA) Presentation: Gaps in your Safety Program?