National Library of Energy BETA

Sample records for timing trapping mechanism

  1. Real-time calibration of a feedback trap

    SciTech Connect (OSTI)

    Gavrilov, Momčilo; Jun, Yonggun; Bechhoefer, John

    2014-09-15

    Feedback traps use closed-loop control to trap or manipulate small particles and molecules in solution. They have been applied to the measurement of physical and chemical properties of particles and to explore fundamental questions in the non-equilibrium statistical mechanics of small systems. These applications have been hampered by drifts in the electric forces used to manipulate the particles. Although the drifts are small for measurements on the order of seconds, they dominate on time scales of minutes or slower. Here, we show that a recursive maximum likelihood (RML) algorithm can allow real-time measurement and control of electric and stochastic forces over time scales of hours. Simulations show that the RML algorithm recovers known parameters accurately. Experimental estimates of diffusion coefficients are also consistent with expected physical properties.

  2. Identification of microscopic hole-trapping mechanisms in nitride semiconductors

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

    John L. Lyons; Krishnaswamy, Karthik; Luke Gordon; Van de Walle, Chris G.; Anderson, Janotti

    2015-12-17

    Hole trapping has been observed in nitride heterostructure devices, where the Fermi level is in the vicinity of the valence-band maximum. Using hybrid density functional calculations, we examine microscopic mechanisms for hole trapping in GaN and AlN. In a defect-free material, hole trapping does not spontaneously occur, but trapping can occur in the vicinity of impurities, such as C-a common unintentional impurity in nitrides. As a result, using Schrödinger-Poisson simulations, we assess the effects of C-derived hole traps on N-face high-electron mobility transistors, which we find to be more detrimental than the previously proposed interface traps.

  3. Thermal Deactivation Mechanisms of Fully-Formed Lean NOx Trap...

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

    Duty Linehaul Platform Project Update Effect of Thermal Aging on NO oxidation and NOx storage in a Fully-Formulated Lean NOx Trap Pt-free, Perovskite-based Lean NOx Trap Catalysts

  4. Spin Self-Rephasing and Very Long Coherence Times in a Trapped Atomic Ensemble

    SciTech Connect (OSTI)

    Deutsch, C.; Reinhard, F.; Schneider, T.; Laloee, F.; Reichel, J. [Laboratoire Kastler Brossel, ENS, UPMC, CNRS, 24 rue Lhomond, 75005 Paris (France); Ramirez-Martinez, F.; Lacroute, C.; Rosenbusch, P. [LNE-SYRTE, Observatoire de Paris, UPMC, CNRS, 61 av de l'Observatoire, 75014 Paris (France); Fuchs, J. N.; Piechon, F. [Laboratoire de Physique des Solides, CNRS UMR 8502, Univ. Paris-Sud, 91405 Orsay (France)

    2010-07-09

    We perform Ramsey spectroscopy on the ground state of ultracold {sup 87}Rb atoms magnetically trapped on a chip in the Knudsen regime. Field inhomogeneities over the sample should limit the 1/e contrast decay time to about 3 s, while decay times of 58{+-}12 s are actually observed. We explain this surprising result by a spin self-rephasing mechanism induced by the identical spin rotation effect originating from particle indistinguishability. We propose a theory of this synchronization mechanism and obtain good agreement with the experimental observations. The effect is general and may appear in other physical systems.

  5. Investigation of Aging Mechanisms in Lean NOx Traps

    SciTech Connect (OSTI)

    Mark Crocker

    2010-03-31

    Lean NO{sub x} traps (LNTs) represent a promising technology for the abatement of NO{sub x} under lean conditions. Although LNTs are starting to find commercial application, the issue of catalyst durability remains problematic. LNT susceptibility to sulfur poisoning is the single most important factor determining effective catalyst lifetime. The NO{sub x} storage element of the catalyst has a greater affinity for SO{sub 3} than it does for NO{sub 2}, and the resulting sulfate is more stable than the stored nitrate. Although this sulfate can be removed from the catalyst by means of high temperature treatment under rich conditions, the required conditions give rise to deactivation mechanisms such as precious metal sintering, total surface area loss, and solid state reactions between the various oxides present. The principle objective of this project was to improve understanding of the mechanisms of lean NO{sub x} trap aging, and to understand the effect of washcoat composition on catalyst aging characteristics. The approach utilized involved detailed characterization of model catalysts prior to and after aging, in tandem with measurement of catalyst performance in NO{sub x} storage and reduction. In this manner, NO{sub x} storage and reduction characteristics were correlated with the evolution of catalyst physico-chemical properties upon aging. Rather than using poorly characterized proprietary catalysts, or simple model catalysts of the Pt/BaO/Al{sub 2}O{sub 3} type (representing the first generation of LNTs), Pt/Rh/BaO/Al{sub 2}O{sub 3} catalysts were employed which also incorporated CeO{sub 2} or CeO{sub 2}-ZrO{sub 2}, representing a model system which more accurately reflects current LNT formulations. Catalysts were prepared in which the concentration of each of the main components was systematically varied: Pt (50, 75 or 100 g/ft{sup 3}), Rh (10 or 20 g/ft{sup 3}), BaO (15, 30 or 45 g/L), and either CeO{sub 2} (0, 50 or 100 g/L) or CeO{sub 2}-ZrO{sub 2} (0, 50

  6. Extended Coherence Time on the Clock Transition of Optically Trapped Rubidium

    SciTech Connect (OSTI)

    Kleine Buening, G.; Will, J.; Ertmer, W.; Rasel, E.; Klempt, C.; Arlt, J.; Ramirez-Martinez, F.; Rosenbusch, P.; Piechon, F.

    2011-06-17

    Optically trapped ensembles are of crucial importance for frequency measurements and quantum memories but generally suffer from strong dephasing due to inhomogeneous density and light shifts. We demonstrate a drastic increase of the coherence time to 21 s on the magnetic field insensitive clock transition of {sup 87}Rb by applying the recently discovered spin self-rephasing [C. Deutsch et al., Phys. Rev. Lett. 105, 020401 (2010)]. This result confirms the general nature of this new mechanism and thus shows its applicability in atom clocks and quantum memories. A systematic investigation of all relevant frequency shifts and noise contributions yields a stability of 2.4x10{sup -11{tau}-1/2}, where {tau} is the integration time in seconds. Based on a set of technical improvements, the presented frequency standard is predicted to rival the stability of microwave fountain clocks in a potentially much more compact setup.

  7. Diurnal activity of soil surface arthropods in agroecosystems: design for an inexpensive time-sorting pitfall trap

    SciTech Connect (OSTI)

    Blumberg, A.Y.; Crossley, D.A. Jr.

    1986-01-01

    The design for an inexpensive time-sorting pitfall trap is presented. The basis of the mechanism is a rotary stepping solenoid powered by lantern batteries. Traps were utilized to sample soil surface arthropods at two hour intervals for five 24 hr periods in 1983. One trap each was placed in conventional tillage (CT) and no-tillage (NT) agroecosystems. Soil arthropod surface activity was greatest in CT on 9 July during the dawn and dusk periods but the data did not indicate other dominant trends. Activity in NT was greatest during dusk on 27 June, but again no other dominant trends were evident. When CT and NT are combined over the sample dates, surface soil arthropod activity peaked during dusk, with a smaller activity peak at dawn. 10 refs., 6 figs.

  8. Real-Time Measurement of Diesel Trap Efficiency | Department of Energy

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

    Measurement of Diesel Trap Efficiency Real-Time Measurement of Diesel Trap Efficiency 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_niemela.pdf (555.43 KB) More Documents & Publications Update on 2007 Diesel Particulate Measurement Research 2007 Diesel Particulate Measurement Research (E-66 Project) Evaluation of the European PMP Methodologies Using Chassis Dynamometer and On-road Testing of Heavy-duty Vehicles

  9. Experimental nonlinear dynamical studies in cesium magneto-optical trap using time-series analysis

    SciTech Connect (OSTI)

    Anwar, M. Islam, R.; Faisal, M.; Sikandar, M.; Ahmed, M.

    2015-03-30

    A magneto-optical trap of neutral atoms is essentially a dissipative quantum system. The fast thermal atoms continuously dissipate their energy to the environment via spontaneous emissions during the cooling. The atoms are, therefore, strongly coupled with the vacuum reservoir and the laser field. The vacuum fluctuations as well as the field fluctuations are imparted to the atoms as random photon recoils. Consequently, the external and internal dynamics of atoms becomes stochastic. In this paper, we have investigated the stochastic dynamics of the atoms in a magneto-optical trap during the loading process. The time series analysis of the fluorescence signal shows that the dynamics of the atoms evolves, like all dissipative systems, from deterministic to the chaotic regime. The subsequent disappearance and revival of chaos was attributed to chaos synchronization between spatially different atoms in the magneto-optical trap.

  10. Long-term Variations of CO2 Trapped in Different Mechanisms in Deep Saline Formations: A Case Study of the Songliao Basin, China

    SciTech Connect (OSTI)

    Zhang, Wei; Li, Yilian; Xu, Tianfu; Cheng, Huilin; Zheng, Yan; Xiong, Peng

    2008-06-10

    The geological storage of CO{sub 2} in deep saline formations is increasing seen as a viable strategy to reduce the release of greenhouse gases to the atmosphere. There are numerous sedimentary basins in China, in which a number of suitable CO{sub 2} geologic reservoirs are potentially available. To identify the multi-phase processes, geochemical changes and mineral alteration, and CO{sub 2} trapping mechanisms after CO{sub 2} injection, reactive geochemical transport simulations using a simple 2D model were performed. Mineralogical composition and water chemistry from a deep saline formation of Songliao Basin were used. Results indicate that different storage forms of CO{sub 2} vary with time. In the CO{sub 2} injection period, a large amount of CO{sub 2} remains as a free supercritical phase (gas trapping), and the amount dissolved in the formation water (solubility trapping) gradually increases. Later, gas trapping decreases, solubility trapping increases significantly due to migration and diffusion of the CO{sub 2} plume, and the amount trapped by carbonate minerals increases gradually with time. The residual CO{sub 2} gas keeps dissolving into groundwater and precipitating carbonate minerals. For the Songliao Basin sandstone, variations in the reaction rate and abundance of chlorite, and plagioclase composition affect significantly the estimates of mineral alteration and CO{sub 2} storage in different trapping mechanisms. The effect of vertical permeability and residual gas saturation on the overall storage is smaller compared to the geochemical factors. However, they can affect the spatial distribution of the injected CO{sub 2} in the formations. The CO{sub 2} mineral trapping capacity could be in the order of ten kilogram per cubic meter medium for the Songliao Basin sandstone, and may be higher depending on the composition of primary aluminosilicate minerals especially the content of Ca, Mg, and Fe.

  11. Time-dependent study of radiation trapping by time-delayed two-photon absorption

    SciTech Connect (OSTI)

    Molander, W.; Belsley, M.; Streater, A.; Burnett, K.

    1983-10-01

    The transport of resonance radiation through an optically thick vapor of Sr atoms is studied. A pulsed dye laser tuned to the 461 nm resonance line excites a narrow (approx. 60 ..mu..m diam) column of Sr atoms along the axis of a cylindrical oven containing Sr vapor and Ar buffer gas. After a delay of less than or equal to 80 ns, a second dye laser excites the atom from the first excited state (5s5p) to a higher excited state (5s7s). The fluorescence from this latter transition is monitored as the second laser is translated parallel to the first. Since the excited state-excited state fluorescence is not trapped the result is a plot of density of atoms in the 5s5p state as a function of position from the originally excited volume. The results are discussed qualitatively.

  12. Breakthrough Time and Mechanical Properties of Edge Sealing in...

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

    Breakthrough Time and Mechanical Properties of Edge Sealing in Different Environmental Conditions Breakthrough Time and Mechanical Properties of Edge Sealing in Different ...

  13. Unraveling the Timing of Fluid Migration and Trap Formation in the Brooks Range Foothills: A Key to Discovering Hydrocarbons

    SciTech Connect (OSTI)

    Catherine L. Hanks

    2008-12-31

    Naturally occurring fractures can play a key role in the evolution and producibility of a hydrocarbon accumulation. Understanding the evolution of fractures in the Brooks Range/Colville basin system of northern Alaska is critical to developing a better working model of the hydrocarbon potential of the region. This study addressed this problem by collecting detailed and regional data on fracture distribution and character, structural geometry, temperature, the timing of deformation along the Brooks Range rangefront and adjacent parts of the Colville basin, and the in situ stress distribution within the Colville basin. This new and existing data then were used to develop a model of how fractures evolved in northern Alaska, both spatially and temporally. The results of the study indicate that fractures formed episodically throughout the evolution of northern Alaska, due to a variety of mechanisms. Four distinct fracture sets were observed. The earliest fractures formed in deep parts of the Colville basin and in the underlying Ellesmerian sequence rocks as these rocks experienced compression associated with the growing Brooks Range fold-and-thrust belt. The orientation of these deep basin fractures was controlled by the maximum in situ horizontal stress in the basin at the time of their formation, which was perpendicular to the active Brooks Range thrust front. This orientation stayed consistently NS-striking for most of the early history of the Brooks Range and Colville basin, but changed to NW-striking with the development of the northeastern Brooks Range during the early Tertiary. Subsequent incorporation of these rocks into the fold-and-thrust belt resulted in overprinting of these deep basin fractures by fractures caused by thrusting and related folding. The youngest fractures developed as rocks were uplifted and exposed. While this general order of fracturing remains consistent across the Brooks Range and adjacent Colville basin, the absolute age at any one

  14. Effect of Cusps in Time-Dependent Quantum Mechanics (Journal...

    Office of Scientific and Technical Information (OSTI)

    Effect of Cusps in Time-Dependent Quantum Mechanics Title: Effect of Cusps in Time-Dependent Quantum Mechanics Authors: Yang, Zeng-hui ; Maitra, Neepa T. ; Burke, Kieron ...

  15. Percolation mechanism through trapping/de-trapping process at defect states for resistive switching devices with structure of Ag/Si{sub x}C{sub 1?x}/p-Si

    SciTech Connect (OSTI)

    Liu, Yanhong; Gao, Ping; Li, La; Peng, Wei [School of Physics and Optoelectronic Engineering, Dalian University of Technology, No. 2 Linggong Road, Ganjingzi District, Dalian 116024 (China); Jiang, Xuening; Zhang, Jialiang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, No. 2 Linggong Road, Ganjingzi District, Dalian 116024 (China)

    2014-08-14

    Pure Si{sub x}C{sub 1?x} (x?>?0.5) and B-containing Si{sub x}C{sub 1?x} (x?>?0.5) based resistive switching devices (RSD) with the structure of Ag/Si{sub x}C{sub 1?x}/p-Si were fabricated and their switching characteristics and mechanism were investigated systematically. Percolation mechanism through trapping/ de-trapping at defect states was suggested for the switching process. Through the introduction of B atoms into Si{sub x}C{sub 1?x}, the density of defect states was reduced, then, the SET and RESET voltages were also decreased. Based on the percolation theory, the dependence of SET/RESET voltage on the density of defect states was analyzed. These results supply a deep understanding for the SiC-based RSD, which have a potential application in extreme ambient conditions.

  16. Thermal Deactivation Mechanisms of Fully-Formed Lean NOx Trap Catalysts Aged by Lean/Rich Cycling

    Broader source: Energy.gov [DOE]

    Catalysts in fully formulated lean NOx traps are aged and evaluated in a bench-flow reactor using simulated diesel engine exhaust.

  17. Breakthrough Time and Mechanical Properties of Edge Sealing in Different

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

    Environmental Conditions | Department of Energy Breakthrough Time and Mechanical Properties of Edge Sealing in Different Environmental Conditions Breakthrough Time and Mechanical Properties of Edge Sealing in Different Environmental Conditions Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado pvmrw13_ps4_saes_bonucci.pdf (1.59 MB) More Documents & Publications Agenda for the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado A

  18. Action spectroscopy of SrCl{sup +} using an integrated ion trap time-of-flight mass spectrometer

    SciTech Connect (OSTI)

    Puri, Prateek Schowalter, Steven J.; Hudson, Eric R.; Kotochigova, Svetlana; Petrov, Alexander

    2014-07-07

    The photodissociation cross-section of SrCl{sup +} is measured in the spectral range of 36 000–46 000 cm{sup −1} using a modular time-of-flight mass spectrometer (TOF-MS). By irradiating a sample of trapped SrCl{sup +} molecular ions with a pulsed dye laser, X{sup 1}Σ{sup +} state molecular ions are electronically excited to the repulsive wall of the A{sup 1}Π state, resulting in dissociation. Using the TOF-MS, the product fragments are detected and the photodissociation cross-section is determined for a broad range of photon energies. Detailed ab initio calculations of the SrCl{sup +} molecular potentials and spectroscopic constants are also performed and are found to be in good agreement with experiment. The spectroscopic constants for SrCl{sup +} are also compared to those of another alkaline earth halogen, BaCl{sup +}, in order to highlight structural differences between the two molecular ions. This work represents the first spectroscopy and ab initio calculations of SrCl{sup +}.

  19. Intermediate Scale Laboratory Testing to Understand Mechanisms of Capillary and Dissolution Trapping during Injection and Post-Injection of CO2 in Heterogeneous Geological Formations

    SciTech Connect (OSTI)

    Illangasekare, Tissa; Trevisan, Luca; Agartan, Elif; Mori, Hiroko; Vargas-Johnson, Javier; Gonzalez-Nicolas, Ana; Cihan, Abdullah; Birkholzer, Jens; Zhou, Quanlin

    2015-03-31

    Carbon Capture and Storage (CCS) represents a technology aimed to reduce atmospheric loading of CO2 from power plants and heavy industries by injecting it into deep geological formations, such as saline aquifers. A number of trapping mechanisms contribute to effective and secure storage of the injected CO2 in supercritical fluid phase (scCO2) in the formation over the long term. The primary trapping mechanisms are structural, residual, dissolution and mineralization. Knowledge gaps exist on how the heterogeneity of the formation manifested at all scales from the pore to the site scales affects trapping and parameterization of contributing mechanisms in models. An experimental and modeling study was conducted to fill these knowledge gaps. Experimental investigation of fundamental processes and mechanisms in field settings is not possible as it is not feasible to fully characterize the geologic heterogeneity at all relevant scales and gathering data on migration, trapping and dissolution of scCO2. Laboratory experiments using scCO2 under ambient conditions are also not feasible as it is technically challenging and cost prohibitive to develop large, two- or three-dimensional test systems with controlled high pressures to keep the scCO2 as a liquid. Hence, an innovative approach that used surrogate fluids in place of scCO2 and formation brine in multi-scale, synthetic aquifers test systems ranging in scales from centimeter to meter scale developed used. New modeling algorithms were developed to capture the processes controlled by the formation heterogeneity, and they were tested using the data from the laboratory test systems. The results and findings are expected to contribute toward better conceptual models, future improvements to DOE numerical codes, more accurate assessment of storage capacities, and optimized placement strategies. This report presents the experimental and modeling methods

  20. COLD TRAPS

    DOE Patents [OSTI]

    Thompson, W.I.

    1958-09-30

    A cold trap is presented for removing a condensable component from a gas mixture by cooling. It consists of a shell, the exterior surface of which is chilled by a refrigerant, and conductive fins welded inside the shell to condense the gas, and distribute the condensate evenly throughout the length of the trap, so that the trap may function until it becomes completely filled with the condensed solid. The contents may then be removed as either a gas or as a liquid by heating the trap. This device has particuinr use as a means for removing uranium hexafluoride from the gaseous diffusion separation process during equipment breakdown and repair periods.

  1. Effect of trapped electron on the dust ion acoustic waves in dusty plasma using time fractional modified Korteweg-de Vries equation

    SciTech Connect (OSTI)

    Nazari-Golshan, A.; Nourazar, S. S.; Department of Mechanical Engineering, Amirkabir University of Technology, Tehran

    2013-10-15

    The time fractional modified Korteweg-de Vries (TFMKdV) equation is solved to study the nonlinear propagation of small but finite amplitude dust ion-acoustic (DIA) solitary waves in un-magnetized dusty plasma with trapped electrons. The plasma is composed of a cold ion fluid, stationary dust grains, and hot electrons obeying a trapped electron distribution. The TFMKdV equation is derived by using the semi-inverse and Agrawal's methods and then solved by the Laplace Adomian decomposition method. Our results show that the amplitude of the DIA solitary waves increases with the increase of time fractional order β, the wave velocity v{sub 0}, and the population of the background free electrons λ. However, it is vice-versa for the deviation from isothermality parameter b, which is in agreement with the result obtained previously.

  2. Collisionless Weibel shocks: Full formation mechanism and timing

    SciTech Connect (OSTI)

    Bret, A. [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Stockem, A. [GoLP/Instituto de Plasmas e Fuso Nuclear, Instituto Superior Tcnico, Universidade de Lisboa, Lisbon (Portugal); Institut fr Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitt Bochum, D-44780 Bochum (Germany); Narayan, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51 Cambridge, Massachusetts 02138 (United States); Silva, L. O. [GoLP/Instituto de Plasmas e Fuso Nuclear, Instituto Superior Tcnico, Universidade de Lisboa, Lisbon (Portugal)

    2014-07-15

    Collisionless shocks in plasmas play an important role in space physics (Earth's bow shock) and astrophysics (supernova remnants, relativistic jets, gamma-ray bursts, high energy cosmic rays). While the formation of a fluid shock through the steepening of a large amplitude sound wave has been understood for long, there is currently no detailed picture of the mechanism responsible for the formation of a collisionless shock. We unravel the physical mechanism at work and show that an electromagnetic Weibel shock always forms when two relativistic collisionless, initially unmagnetized, plasma shells encounter. The predicted shock formation time is in good agreement with 2D and 3D particle-in-cell simulations of counterstreaming pair plasmas. By predicting the shock formation time, experimental setups aiming at producing such shocks can be optimised to favourable conditions.

  3. Entanglement generation in planar Penning traps

    SciTech Connect (OSTI)

    Martins, Ana M.; Mendonca, J. T.; Guerreiro, A.; Vieira, V. R.

    2010-07-15

    We investigate the generation of entanglement between the axial degrees of freedom of electrons confined in separated locations in planar Penning traps. We show that there are two different sources of entanglement: one is related with the mechanism of switching on and off the electrical coupling between the two electrons, and the other is due to the two-quanta-transition term of the coupling interaction. We show that the degree of entanglement can be controlled by adjusting the strength of the coupling between the traps and the time of interaction. We show that the coupled electrons behave as a temporal active interferometer.

  4. Experimental investigation of supercritical CO2 trapping mechanisms at the Intermediate Laboratory Scale in well-defined heterogeneous porous media

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

    Trevisan, Luca; Pini, Ronny; Cihan, Abdullah; Birkholzer, Jens T.; Zhou, Quanlin; Illangasekare, Tissa H.

    2014-12-31

    The heterogeneous nature of typical sedimentary formations can play a major role in the propagation of the CO2 plume, eventually dampening the accumulation of mobile phase underneath the caprock. From core flooding experiments, it is also known that contrasts in capillary threshold pressure due to different pore size can affect the flow paths of the invading and displaced fluids and consequently influence the build- up of non-wetting phase (NWP) at interfaces between geological facies. The full characterization of the geologic variability at all relevant scales and the ability to make observations on the spatial and temporal distribution of the migrationmore » and trapping of supercritical CO2 is not feasible from a practical perspective. To provide insight into the impact of well-defined heterogeneous systems on the flow dynamics and trapping efficiency of supercritical CO2 under drainage and imbibition conditions, we present an experimental investigation at the meter scale conducted in synthetic sand reservoirs packed in a quasi-two-dimensional flow-cell. Two immiscible displacement experiments have been performed to observe the preferential entrapment of NWP in simple heterogeneous porous media. The experiments consisted of an injection, a fluid redistribution, and a forced imbibition stages conducted in an uncorrelated permeability field and a homogeneous base case scenario. We adopted x-ray attenuation analysis as a non-destructive technique that allows a precise measurement of phase saturations throughout the entire flow domain. By comparing a homogeneous and a heterogeneous scenario we have identified some important effects that can be attributed to capillary barriers, such as dampened plume advancement, higher non-wetting phase saturations, larger contact area between the injected and displaced phases, and a larger range of non-wetting phase saturations.« less

  5. TRAP) K. S. Marble

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

    The trap's electric quadrupole field is provided by a SHIP TRAPS RF electronic circuit to the four segmented electrodes at the center of the trap while the trap's 7 Tesla magnetic ...

  6. COLD TRAP

    DOE Patents [OSTI]

    Milleron, N.

    1963-03-12

    An improved linear-flow cold trap is designed for highvacuum applications such as mitigating back migration of diffusion pump oil moiecules. A central pot of liquid nitrogen is nested within and supported by a surrounding, vertical, helical coil of metai sheet, all enveloped by a larger, upright, cylindrical, vacuum vessel. The vertical interstices between successive turns of the coil afford lineal, axial, high-vacuum passages between open mouths at top and bottom of said vessel, while the coil, being cold by virtue of thermal contact of its innermost turn with the nitrogen pot, affords expansive proximate condensation surfaces. (AEC)

  7. VACUUM TRAP

    DOE Patents [OSTI]

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  8. In-situ, Real-Time Monitoring of Mechanical and Chemical Structure...

    Office of Scientific and Technical Information (OSTI)

    Conference: In-situ, Real-Time Monitoring of Mechanical and Chemical Structure Changes in ... Citation Details In-Document Search Title: In-situ, Real-Time Monitoring of Mechanical and ...

  9. In-situ, Real-Time Monitoring of Mechanical and Chemical Structure Changes

    Office of Scientific and Technical Information (OSTI)

    in a V2O5 Battery Electrode Using a MEMS Optical Sensor (Conference) | SciTech Connect In-situ, Real-Time Monitoring of Mechanical and Chemical Structure Changes in a V2O5 Battery Electrode Using a MEMS Optical Sensor Citation Details In-Document Search Title: In-situ, Real-Time Monitoring of Mechanical and Chemical Structure Changes in a V2O5 Battery Electrode Using a MEMS Optical Sensor This work presents the first demonstration of a MEMS optical sensor for in-situ, real-time monitoring of

  10. Experimental investigation of supercritical CO2 trapping mechanisms at the Intermediate Laboratory Scale in well-defined heterogeneous porous media

    SciTech Connect (OSTI)

    Trevisan, Luca; Pini, Ronny; Cihan, Abdullah; Birkholzer, Jens T.; Zhou, Quanlin; Illangasekare, Tissa H.

    2014-12-31

    The heterogeneous nature of typical sedimentary formations can play a major role in the propagation of the CO2 plume, eventually dampening the accumulation of mobile phase underneath the caprock. From core flooding experiments, it is also known that contrasts in capillary threshold pressure due to different pore size can affect the flow paths of the invading and displaced fluids and consequently influence the build- up of non-wetting phase (NWP) at interfaces between geological facies. The full characterization of the geologic variability at all relevant scales and the ability to make observations on the spatial and temporal distribution of the migration and trapping of supercritical CO2 is not feasible from a practical perspective. To provide insight into the impact of well-defined heterogeneous systems on the flow dynamics and trapping efficiency of supercritical CO2 under drainage and imbibition conditions, we present an experimental investigation at the meter scale conducted in synthetic sand reservoirs packed in a quasi-two-dimensional flow-cell. Two immiscible displacement experiments have been performed to observe the preferential entrapment of NWP in simple heterogeneous porous media. The experiments consisted of an injection, a fluid redistribution, and a forced imbibition stages conducted in an uncorrelated permeability field and a homogeneous base case scenario. We adopted x-ray attenuation analysis as a non-destructive technique that allows a precise measurement of phase saturations throughout the entire flow domain. By comparing a homogeneous and a heterogeneous scenario we have identified some important effects that can be attributed to capillary barriers, such as dampened plume advancement, higher non-wetting phase saturations, larger contact area between the injected and displaced phases, and a larger range of non-wetting phase saturations.

  11. Microfabricated ion trap array

    DOE Patents [OSTI]

    Blain, Matthew G.; Fleming, James G.

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  12. November 18, 2010: Antimatter Trapped and Stored | Department of Energy

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

    8, 2010: Antimatter Trapped and Stored November 18, 2010: Antimatter Trapped and Stored November 18, 2010: Antimatter Trapped and Stored November 18, 2010 The Department's Lawrence Berkeley National Laboratory (LBNL) announces that atoms of antimatter have been trapped and stored for the first time in a magnetic bottle-like device by the ALPHA collaboration, an international team of scientists working at CERN, the European Organization for Nuclear Research near Geneva, Switzerland. Scientists

  13. VACUUM TRAP AND VALVE COMBINATION

    DOE Patents [OSTI]

    Milleron, N.; Levenson, L.

    1963-02-19

    This patent relates to a vacuum trap and valve combination suitable for use in large ultra-high vacuum systems. The vacuum trap is a chamber having an inlet and outlet opening which may be made to communicate with a chamber to be evacuated and a diffusion pump, respectively. A valve is designed to hermeticaliy seal with inlet opening and, when opened, block the line-of- sight'' between the inlet and outlet openings, while allowing a large flow path between the opened vaive and the side walls of the trap. The interior of the trap and the side of the valve facing the inlet opening are covered with an impurity absorbent, such as Zeolite or activated aluminum. Besides the advantage of combining two components of a vacuum system into one, the present invention removes the need for a baffle between the pump and the chamber to be evacuated. In one use of a specific embodiment of this invention, the transmission probability was 45 and the partial pressure of the pump fluid vapor in the vacuum chamber was at least 100 times lower than its vapor pressure. (AEC)

  14. Simplifying steam trap selection

    SciTech Connect (OSTI)

    Debat, R.J. )

    1994-01-01

    In the current economic world order, there is an obligation to eliminate waste and conserve economic and natural resources. One trap blowing 100-lb of steam through a 1/4-in. orifice can cost more than $12,000 a year in wasted energy. Richard J. Debat of Armstrong International, Inc. explains the operating principles of the four basic types of steam traps as the first step in simplifying the selection process so the right trap can be specified for a given application.

  15. Greenpower Trap Mufflerl System

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

    Water GREENPOWER TRAP-MUFFLER(tm) System (US Patent 6892531, 5085049, PCT, others pending) www.dieselnet.comdr.rim CatalystDPF EGR Accumulator Air Intake Filter Turbo Charger ...

  16. Steam trap monitor

    DOE Patents [OSTI]

    Ryan, M.J.

    1987-05-04

    A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (a hot finger) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellow in providing an indication of total energy (steam + condensate) of the system. Processing means coupled to and responsive to outputs from the hot and cold fingers subtracts the former from the latter to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning. 2 figs.

  17. Microfabricated cylindrical ion trap

    DOE Patents [OSTI]

    Blain, Matthew G.

    2005-03-22

    A microscale cylindrical ion trap, having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale cylindrical ion trap to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The microscale CIT has a reduced ion mean free path, allowing operation at higher pressures with less expensive and less bulky vacuum pumping system, and with lower battery power than conventional- and miniature-sized ion traps. The reduced electrode voltage enables integration of the microscale cylindrical ion trap with on-chip integrated circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of microscale cylindrical ion traps can be realized in truly field portable, handheld microanalysis systems.

  18. Requirements-Driven Diesel Catalyzed Particulate Trap Design and

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

    Optimization | Department of Energy Requirements-Driven Diesel Catalyzed Particulate Trap Design and Optimization Requirements-Driven Diesel Catalyzed Particulate Trap Design and Optimization 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_harris.pdf (388.49 KB) More Documents & Publications Diesel Emission Control Technology Review Investigation of Aging Mechanisms in Lean NOx Traps Diesel Particulate Filters: Market Introducution in Euro

  19. Chemical dynamics in the gas phase: Time-dependent quantum mechanics of chemical reactions

    SciTech Connect (OSTI)

    Gray, S.K.

    1993-12-01

    A major goal of this research is to obtain an understanding of the molecular reaction dynamics of three and four atom chemical reactions using numerically accurate quantum dynamics. This work involves: (i) the development and/or improvement of accurate quantum mechanical methods for the calculation and analysis of the properties of chemical reactions (e.g., rate constants and product distributions), and (ii) the determination of accurate dynamical results for selected chemical systems, which allow one to compare directly with experiment, determine the reliability of the underlying potential energy surfaces, and test the validity of approximate theories. This research emphasizes the use of recently developed time-dependent quantum mechanical methods, i.e. wave packet methods.

  20. Thermoelectrically cooled water trap

    DOE Patents [OSTI]

    Micheels, Ronald H.

    2006-02-21

    A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

  1. Dark soliton decay due to trap anharmonicity in atomic Bose-Einstein condensates

    SciTech Connect (OSTI)

    Parker, N. G.; Proukakis, N. P.; Adams, C. S.

    2010-03-15

    A number of recent experiments with nearly pure atomic Bose-Einstein condensates have confirmed the predicted dark soliton oscillations when under harmonic trapping. However, a dark soliton propagating in an inhomogeneous condensate has also been predicted to be unstable to the emission of sound waves. Although harmonic trapping supports an equilibrium between the coexisting soliton and sound, we show that the ensuing dynamics are sensitive to trap anharmonicities. Such anharmonicities can break the soliton-sound equilibrium and lead to the net decay of the soliton on a considerably shorter time scale than other dissipation mechanisms. Thus, we propose that small realistic modifications to existing experimental setups could enable the experimental observation of this decay channel.

  2. Asymmetric ion trap

    DOE Patents [OSTI]

    Barlow, S.E.; Alexander, M.L.; Follansbee, J.C.

    1997-12-02

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode is disclosed. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity. 4 figs.

  3. Asymmetric ion trap

    DOE Patents [OSTI]

    Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

    1997-01-01

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

  4. System and method for trapping and measuring a charged particle in a liquid

    DOE Patents [OSTI]

    Reed, Mark A; Krstic, Predrag S; Guan, Weihua; Zhao, Xiongce

    2013-07-23

    A system and method for trapping a charged particle is disclosed. A time-varying periodic multipole electric potential is generated in a trapping volume. A charged particle under the influence of the multipole electric field is confined to the trapping volume. A three electrode configuration giving rise to a 3D Paul trap and a four planar electrode configuration giving rise to a 2D Paul trap are disclosed.

  5. System and method for trapping and measuring a charged particle in a liquid

    DOE Patents [OSTI]

    Reed, Mark A; Krstic, Predrag S; Guan, Weihua; Zhao, Xiongce

    2012-10-23

    A system and method for trapping a charged particle is disclosed. A time-varying periodic multipole electric potential is generated in a trapping volume. A charged particle under the influence of the multipole electric field is confined to the trapping volume. A three electrode configuration giving rise to a 3D Paul trap and a four planar electrode configuration giving rise to a 2D Paul trap are disclosed.

  6. Analysis of a magnetically trapped atom clock

    SciTech Connect (OSTI)

    Kadio, D.; Band, Y. B.

    2006-11-15

    We consider optimization of a rubidium atom clock that uses magnetically trapped Bose condensed atoms in a highly elongated trap, and determine the optimal conditions for minimum Allan variance of the clock using microwave Ramsey fringe spectroscopy. Elimination of magnetic field shifts and collisional shifts are considered. The effects of spin-dipolar relaxation are addressed in the optimization of the clock. We find that for the interstate interaction strength equal to or larger than the intrastate interaction strengths, a modulational instability results in phase separation and symmetry breaking of the two-component condensate composed of the ground and excited hyperfine clock levels, and this mechanism limits the clock accuracy.

  7. Steam trap monitor

    DOE Patents [OSTI]

    Ryan, Michael J. (Plainfield, IL)

    1988-01-01

    A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (the combination of a hot finger and thermocouple well) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellows in providing an indication of total energy (steam+condensate) of the system. Processing means coupled to and responsive to outputs from the thermocouple well hot and cold fingers subtracts the condensate energy as measured by the hot finger and thermocouple well from the total energy as measured by the cold finger to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning.

  8. WATER-TRAPPED WORLDS

    SciTech Connect (OSTI)

    Menou, Kristen [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

    2013-09-01

    Although tidally locked habitable planets orbiting nearby M-dwarf stars are among the best astronomical targets to search for extrasolar life, they may also be deficient in volatiles and water. Climate models for this class of planets show atmospheric transport of water from the dayside to the nightside, where it is precipitated as snow and trapped as ice. Since ice only slowly flows back to the dayside upon accumulation, the resulting hydrological cycle can trap a large amount of water in the form of nightside ice. Using ice sheet dynamical and thermodynamical constraints, I illustrate how planets with less than about a quarter the Earth's oceans could trap most of their surface water on the nightside. This would leave their dayside, where habitable conditions are met, potentially dry. The amount and distribution of residual liquid water on the dayside depend on a variety of geophysical factors, including the efficiency of rock weathering at regulating atmospheric CO{sub 2} as dayside ocean basins dry up. Water-trapped worlds with dry daysides may offer similar advantages as land planets for habitability, by contrast with worlds where more abundant water freely flows around the globe.

  9. Antihydrogen Trapped in the ALPHA Experiment

    ScienceCinema (OSTI)

    None

    2011-04-25

    In 2010 the ALPHA collaboration succeeded in trapping antihydrogen atoms for the first time.[i]  Stored antihydrogen promises to be a unique tool for making high precision measurements of the structure of this first anti-atom. Achieving this milestone presented several substantial experimental challenges and this talk will describe how they were overcome.   The unique design features of the ALPHA apparatus will be explained.[ii]  These allow a high intensity positron source and an antiproton imaging detector similar to the one used in the ATHENA[iii] experiment to be combined with an innovative magnet design of the anti-atom trap. This seeks to minimise the perturbations to trapped charged particles which may cause particle loss and heating[iv].   The diagnostic techniques used to measure the diameter, number, density, and temperatures of both plasmas will be presented as will the methods developed to actively compress and cool of both plasma species to sizes and temperatures [v],[vi], [vii] where trapping attempts with a reasonable chance of success can be tried.   The results of the successful trapping experiments will be outlined as well as some subsequent experiments to improve the trapping rate and storage time. [i] 'Trapped antihydrogen' G.B. Andresen et al., Nature 468, 673 (2010) [ii]'A Magnetic Trap for Antihydrogen Confinement' W. Bertsche et al., Nucl. Instr. Meth. Phys. Res. A566, 746 (2006) [iii] Production and detection of cold antihydrogen atoms M.Amoretti et al., Nature 419, 456 (2002). [iv]' Antihydrogen formation dynamics in a multipolar neutral anti-atom trap' G.B. Andresen et al., Phys. Lett. B 685, 141 (2010) [v]' Evaporative Cooling of Antiprotons to Cryogenic Temperatures',                                   G.B. Andresen et al. Phys. Rev. Lett 105, 013003 (2010) [vi]'Compression of Antiproton Clouds for Antihydrogen Trapping' G. B. Andresen et al. Phys. Rev. Lett 100, 203401 (2008) [vii]  'Autoresonant

  10. Ion funnel ion trap and process

    DOE Patents [OSTI]

    Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

    2011-02-15

    An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

  11. Geotechnical factors influencing a time-dependent deformation mechanism around an entry in a dipping seam

    SciTech Connect (OSTI)

    Larson, M.K.; Maleki, H.

    1996-12-01

    The U.S. Bureau of Mines and Cyprus Shoshone Coal Corp. conducted a study of deformation mechanisms in strata around a longwall gate road system at two sites in an underground coal mine near Hanna, WY. Of particular interest was time-dependent (on the order of several months) roof deformation. Strata above and below the coal seam are very weak, carbonaceous mudstones that have cohesionless planes of weakness oriented along bedding, which dips approximately 8{degrees} to 16{degrees} at N 49{degrees} E. An extensive array of instrumented roof bolts, roof extensometers, and biaxial stressmeters were installed during development mining at these two sites under variable depth of cover [183 to 335 in (600 to 1,100 ft)], seam dip (10{degrees} to 16{degrees}), and top coal thickness [estimated to be 0.30 to 0.61 in (1 to 2 ft) on the downdip side of the entry]. Bolt load and roof deformation histories during the entry development periods were compared. Bolt loads at site 2 were less than those at site 1, which is consistent with the amount of overburden. Deformation magnitudes at site 2 were similar to those at site 1, but deformation rates were approximately 44% greater and nearly constant over time, whereas the deformation rates at site 1 decreased exponentially over time. Also, most deformation occurred above the bolt horizon at site two, but extensometer measurements at site 1 showed that a significant amount of deformation occurred within the bolt horizon. The most significant factor that influenced bolt tension and time-dependent strata deformation was strength and Young`s modulus of the strata. Finite-difference models support this conclusion.

  12. Theory of magic optical traps for Zeeman-insensitive clock transitions in alkali-metal atoms

    SciTech Connect (OSTI)

    Derevianko, Andrei

    2010-05-15

    Precision measurements and quantum-information processing with cold atoms may benefit from trapping atoms with specially engineered, 'magic' optical fields. At the magic trapping conditions, the relevant atomic properties remain immune to strong perturbations by the trapping fields. Here we develop a theoretical analysis of magic trapping for especially valuable Zeeman-insensitive clock transitions in alkali-metal atoms. The involved mechanism relies on applying a magic bias B field along a circularly polarized trapping laser field. We map out these B fields as a function of trapping laser wavelength for all commonly used alkalis. We also highlight a common error in evaluating Stark shifts of hyperfine manifolds.

  13. Radial cold trap

    DOE Patents [OSTI]

    Grundy, Brian R.

    1981-01-01

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume.

  14. Radial cold trap

    DOE Patents [OSTI]

    Grundy, B.R.

    1981-09-29

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume. 2 figs.

  15. Filter vapor trap

    DOE Patents [OSTI]

    Guon, Jerold

    1976-04-13

    A sintered filter trap is adapted for insertion in a gas stream of sodium vapor to condense and deposit sodium thereon. The filter is heated and operated above the melting temperature of sodium, resulting in a more efficient means to remove sodium particulates from the effluent inert gas emanating from the surface of a liquid sodium pool. Preferably the filter leaves are precoated with a natrophobic coating such as tetracosane.

  16. Steam trap maintenance management saves $180,000 annually

    SciTech Connect (OSTI)

    Franks, F.C.; Wickersham, C.

    1985-12-01

    The Reichhold Chemical plant is located in Elizabeth, NJ. At this location, the cost of steam had skyrocketed to $5.30 per million Btu. The plant has 600 steam traps manufactured by ten different companies. Some 17 different models of traps are used with 33 piping configurations. There are five different operating pressures throughout the plant ranging from 15-175 psig, including 30, 65, and 120 psig. Five different applications of steam usage can be broken down as follows: steam tracing (56%); drip (21%); comfort heating (18%); tank coil (4%); and process (1%). In the fall of 1983, the annual yearly inspection of steam traps was supplanted with an independent trap survey service, specializing in detecting the malfunctioning of various types of steam traps. The basic program included location and tagging of all steam traps; survey and inspection of steam trap population; development of a trap map; and full computer analysis of collected data. It was determined that approximately 3919 lb/hr of steam could be saved by repairing the failed open traps and implementing the report's recommendations. There were also benefits from fixing the failed closed traps which were out of service at the time of the survey. These traps do not allow the flow of steam or condensate to pass through the orifice. This condition causes condensate to back up and reduce efficiency. The maintenance management has been pleased with the results and recommendations of the program. It has provided them with a complete inventory and status report of the 600 traps plantwide. It saved $180,000 over the previous year in energy expenditures. This was the most important contribution in lowering the plant energy costs.

  17. Fluctuation characteristics and transport properties of collisionless trapped electron mode turbulence

    SciTech Connect (OSTI)

    Xiao Yong; Holod, Ihor; Zhang Wenlu; Lin Zhihong [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Klasky, Scott [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2010-02-15

    The collisionless trapped electron mode turbulence is investigated by global gyrokinetic particle simulation. The zonal flow dominated by low frequency and short wavelength acts as a very important saturation mechanism. The turbulent eddies are mostly microscopic, but with a significant portion in the mesoscale. The ion heat transport is found to be diffusive and follows the local radial profile of the turbulence intensity. However, the electron heat transport demonstrates some nondiffusive features and only follows the global profile of the turbulence intensity. The nondiffusive features of the electron heat transport is further confirmed by nonlognormal statistics of the flux-surface-averaged electron heat flux. The radial and time correlation functions are calculated to obtain the radial correlation length and autocorrelation time. Characteristic time scale analysis shows that the zonal flow shearing time and eddy turnover time are very close to the effective decorrelation time, which suggests that the trapped electrons move with the fluid eddies. The fluidlike behaviors of the trapped electrons and the persistence of the mesoscale eddies contribute to the transition of the electron turbulent transport from gyro-Bohm scaling to Bohm scaling when the device size decreases.

  18. In-situ, Real-Time Monitoring of Mechanical and Chemical Structure...

    Office of Scientific and Technical Information (OSTI)

    of Mechanical and Chemical Structure Changes in a V2O5 Battery Electrode Using a MEMS Optical Sensor Jung, H. University of Maryland; Gerasopoulos, K. University of...

  19. Final Technical Report of project: "Contactless Real-Time Monitoring of Paper Mechanical Behavior During Papermaking"

    SciTech Connect (OSTI)

    Emmanuel Lafond; Paul Ridgway; Ted Jackson; Rick Russo; Ken Telschow; Vance Deason; Yves Berthelot; David Griggs; Xinya Zhang; Gary Baum

    2005-08-30

    The early precursors of laser ultrasonics on paper were Prof. Y. Berthelot from the Georgia Institute of Technology/Mechanical Engineering department, and Prof. P. Brodeur from the Institute of Paper Science and Technology, both located in Atlanta, Georgia. The first Ph.D. thesis that shed quite some light on the topic, but also left some questions unanswered, was completed by Mont A. Johnson in 1996. Mont Johnson was Prof. Berthelot's student at Georgia Tech. In 1997 P. Brodeur proposed a project involving himself, Y. Berthelot, Dr. Ken Telschow and Mr. Vance Deason from INL, Honeywell-Measurex and Dr. Rick Russo from LBNL. The first time the proposal was not accepted and P. Brodeur decided to re-propose it without the involvement from LBNL. Rick Russo proposed a separate project on the same topic on his side. Both proposals were finally accepted and work started in the fall of 1997 on the two projects. Early on, the biggest challenge was to find an optical detection method which could detect laser-induced displacements of the web surface that are of the order of .1 micron in the ultrasonic range. This was to be done while the web was having an out-of-plane amplitude of motion in the mm range due to web flutter; while moving at 10 m/s to 30 m/s in the plane of the web, on the paper machine. Both teams grappled with the same problems and tried similar methods in some cases, but came up with two similar but different solutions one year later. The IPST, GT, INL team found that an interferometer made by Lasson Technologies Inc. using the photo-induced electro-motive force in Gallium Arsenide was able to detect ultrasonic waves up to 12-15 m/s. It also developed in house an interferometer using the Two-Wave Mixing effect in photorefractive crystals that showed good promises for on-line applications, and experimented with a scanning mirror to reduce motion-induced texture noise from the web and improve signal to noise ratio. On its side, LBNL had the idea to combine a

  20. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally...

  1. Gated charged-particle trap

    DOE Patents [OSTI]

    Benner, W. Henry

    1999-01-01

    The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector.

  2. Scalable error correction in distributed ion trap computers

    SciTech Connect (OSTI)

    Oi, Daniel K. L.; Devitt, Simon J.; Hollenberg, Lloyd C. L.

    2006-11-15

    A major challenge for quantum computation in ion trap systems is scalable integration of error correction and fault tolerance. We analyze a distributed architecture with rapid high-fidelity local control within nodes and entangled links between nodes alleviating long-distance transport. We demonstrate fault-tolerant operator measurements which are used for error correction and nonlocal gates. This scheme is readily applied to linear ion traps which cannot be scaled up beyond a few ions per individual trap but which have access to a probabilistic entanglement mechanism. A proof-of-concept system is presented which is within the reach of current experiment.

  3. Zinc-oxide charge trapping memory cell with ultra-thin chromium-oxide trapping layer

    SciTech Connect (OSTI)

    El-Atab, Nazek; Rizk, Ayman; Nayfeh, Ammar; Okyay, Ali K.; UNAM-National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara

    2013-11-15

    A functional zinc-oxide based SONOS memory cell with ultra-thin chromium oxide trapping layer was fabricated. A 5 nm CrO{sub 2} layer is deposited between Atomic Layer Deposition (ALD) steps. A threshold voltage (V{sub t}) shift of 2.6V was achieved with a 10V programming voltage. Also for a 2V V{sub t} shift, the memory with CrO{sub 2} layer has a low programming voltage of 7.2V. Moreover, the deep trapping levels in CrO{sub 2} layer allows for additional scaling of the tunnel oxide due to an increase in the retention time. In addition, the structure was simulated using Physics Based TCAD. The results of the simulation fit very well with the experimental results providing an understanding of the charge trapping and tunneling physics.

  4. Hydrogen isotope trapping in Al-Cu binary alloys

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

    Chao, Paul; Karnesky, Richard A.

    2016-01-01

    In this study, the trapping mechanisms for hydrogen isotopes in Al–X Cu (0.0 at. % < X < 3.5 at. %) alloys were investigated using thermal desorption spectroscopy (TDS), electrical conductivity, and differential scanning calorimetry. Constant heating rate TDS was used to determine microstructural trap energies and occupancies. In addition to the trapping states in pure Al reported in the literature (interstitial lattice sites, dislocations, and vacancies), a trap site due to Al–Cu intermetallic precipitates is observed. The binding energy of this precipitate trap is (18 ± 3) kJ•mol–1 (0.19 ± 0.03 eV). Typical occupancy of this trap is high;more » for Al–2.6 at. % Cu (a Cu composition comparable to that in AA2219) charged at 200 °C with 130 MPa D2 for 68 days, there is ca. there is 3.15×10–7 mol D bound to the precipitate trap per mol of Al, accounting for a third of the D in the charged sample.« less

  5. Hydrogen isotope trapping in Al-Cu binary alloys

    SciTech Connect (OSTI)

    Chao, Paul; Karnesky, Richard A.

    2016-01-01

    In this study, the trapping mechanisms for hydrogen isotopes in Al–X Cu (0.0 at. % < X < 3.5 at. %) alloys were investigated using thermal desorption spectroscopy (TDS), electrical conductivity, and differential scanning calorimetry. Constant heating rate TDS was used to determine microstructural trap energies and occupancies. In addition to the trapping states in pure Al reported in the literature (interstitial lattice sites, dislocations, and vacancies), a trap site due to Al–Cu intermetallic precipitates is observed. The binding energy of this precipitate trap is (18 ± 3) kJ•mol–1 (0.19 ± 0.03 eV). Typical occupancy of this trap is high; for Al–2.6 at. % Cu (a Cu composition comparable to that in AA2219) charged at 200 °C with 130 MPa D2 for 68 days, there is ca. there is 3.15×10–7 mol D bound to the precipitate trap per mol of Al, accounting for a third of the D in the charged sample.

  6. CNEEC - Nanophotonic Light Trapping Tutorial by Shanhui Fan

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

    Nanophotonic Light Trapping for Solar Cells

  7. Thermostatic steam trap

    SciTech Connect (OSTI)

    Anderson, A.H.; Mac Nicol, A.E.

    1987-03-03

    A thermostatic trap is described for a heating system having a feed pipe connected to a source of steam and a discharge pipe for discharge of condensate and comprising: housing means defining a volume and comprising a bowl shaped body, a removable cover therefor, a housing inlet pipe portion projecting from a side wall portion of the body and adapted for connection to the discharge pipe. A housing outlet pipe portion projects from a bottom wall portion of the body, and an outlet orifice defined by the bottom wall portion and extends between the volume and the outlet pipe portion; a valve body means retained within the volume and comprising an end wall, a side wall and a retaining ring portion that together define a valve chamber. The end wall defines a valve inlet opening communicating with the chamber and an annular valve seat within the chamber and encircling the valve inlet opening. The valve body means comprises a valve outlet pipe that defines a valve outlet opening axially aligned with the valve inlet opening and communicating with the chamber, the outlet pipe being fixed in the outlet orifice; a resilient, annular seal means disposed within the valve chamber and encircling the valve inlet opening; and a bi-metallic disc disposed within the valve chamber between the annular seal means and the outlet opening and having an outer peripheral portion retained by the retaining ring portion of the valve body means.

  8. Protection #2: Trap and Remove Sediment

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

    Trap and Remove Sediment Protection 2: Trap and Remove Sediment The 3 Protections Defense in Depth August 1, 2013 Sediment behind LA Canyon weir is sampled and excavated...

  9. Fundamental Electroweak Studies using Trapped Ions & Atoms

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

    collaboration performs fundamental electroweak studies on trapped ions & atoms. We use neutral atom and ion trapping techniques at radioactive ion beam facilities here and...

  10. Trapping of oil drops in a noncircular pore throat and mobilization upon contact with a surfactant

    SciTech Connect (OSTI)

    Arriola, A.; Green, D.W.; Willhite, G.P.

    1983-02-01

    An experimental apparatus was developed to study trapping and mobilization of oil drops in a capillary of square cross section (100 microns X 100 microns (100 ..mu..m X 100 ..mu..m)) having a constriction also approximately square in shape. Experiments to investigate trapping consisted of injecting a drop of nonwetting phase liquid (''oil'') into a flowing water stream (wetting phase). Pre-equilibrated alcohol/water systems were used to study effects of interfacial tension (IFT). A drop was displaced toward the constriction by the flowing water. The behavior of the drop as it approached and was trapped by the constriction or as it moved through the constriction was observed as a function of flow rate, drop length, and IFT between the water and nonwetting liquid. Mobilization by surfactants was investigated by conducting a series of displacement experiments in the capillary cell. Data from the mobilization experiments allowed two mechanisms to be identified. In Mechanism 1, minute quantities of the surfactant and/or cosurfactant were carried ahead of the main surfactant slug by brine that bypassed the slug. This reduced the IFT between the oil and brine. The oil drop moved further into the constriction and a snap-off process ensued. Mechanism 2 occurred when a sharp interface of the surfactant slug contacted the trailing edge of a nonane drop that was either trapped or in a snap-off process. A series of events that mobilized the drop occurred over a very short time period (< 4.0 seconds). The events included rupture of the drop interface, rolling motions inside the drop with resulting emulsification, and passage of the emulsified drop through the pore constriction without snap-off.

  11. Time

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

    3 4 5 6 7 8 9 10 Time with respect to the BNB Trigger Time [µs] 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Fractional Flash Count per 0.15 µs with respect to Cosmic Background Measured Cosmic Rate (Beam-Off) BNB Trigger Data (Beam-On) [4.51E18 POT]

  12. Time

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

    10 15 20 Time with respect to the NuMI Trigger Time [µs] 0.9 1.0 1.1 1.2 1.3 1.4 1.5 Fractional Flash Count per 0.5 µs with respect to Cosmic Background Measured Cosmic Rate (Beam-Off) NuMI Trigger Data (Beam-On) [4.83E18 POT]

  13. Gated charged-particle trap

    DOE Patents [OSTI]

    Benner, W.H.

    1999-03-09

    The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector. 5 figs.

  14. Hydrodynamic enhanced dielectrophoretic particle trapping

    DOE Patents [OSTI]

    Miles, Robin R.

    2003-12-09

    Hydrodynamic enhanced dielectrophoretic particle trapping carried out by introducing a side stream into the main stream to squeeze the fluid containing particles close to the electrodes producing the dielelectrophoretic forces. The region of most effective or the strongest forces in the manipulating fields of the electrodes producing the dielectrophoretic forces is close to the electrodes, within 100 .mu.m from the electrodes. The particle trapping arrangement uses a series of electrodes with an AC field placed between pairs of electrodes, which causes trapping of particles along the edges of the electrodes. By forcing an incoming flow stream containing cells and DNA, for example, close to the electrodes using another flow stream improves the efficiency of the DNA trapping.

  15. Inspect and Repair Steam Traps

    SciTech Connect (OSTI)

    Not Available

    2006-01-01

    This revised ITP tip sheet on inspecting and repairing steam traps provide how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

  16. Mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  17. Mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, D.D.; Keville, R.F.

    1995-09-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  18. Observation of cold Rb{sub 2} molecules trapped in an optical dipole trap using a laser-pulse-train technique

    SciTech Connect (OSTI)

    Menegatti, Carlos R.; Marangoni, Bruno S.; Marcassa, Luis G.

    2011-11-15

    In this work, we have developed and characterized a laser-pulse-train technique to observe cold Rb{sub 2} molecules trapped in an optical dipole trap. The molecules are produced in a magneto-optical trap, and then loaded into a crossed optical dipole trap. The time evolution of the molecular population is obtained by applying a laser pulse train, which photoionizes the ground-state molecules through intermediate molecular bands. Our results show that this technique allows us to obtain a faster data acquisition rate of the time evolution of the molecule population than other techniques.

  19. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  20. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  1. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  2. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  3. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Electron Trapping by Molecular Vibration Print Wednesday, 27 April 2005 00:00 In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can

  4. Short-time asymptotics of a rigorous path integral for N = 1 supersymmetric quantum mechanics on a Riemannian manifold

    SciTech Connect (OSTI)

    Fine, Dana S.; Sawin, Stephen

    2014-06-15

    Following Feynman's prescription for constructing a path integral representation of the propagator of a quantum theory, a short-time approximation to the propagator for imaginary-time, N = 1 supersymmetric quantum mechanics on a compact, even-dimensional Riemannian manifold is constructed. The path integral is interpreted as the limit of products, determined by a partition of a finite time interval, of this approximate propagator. The limit under refinements of the partition is shown to converge uniformly to the heat kernel for the Laplace-de Rham operator on forms. A version of the steepest descent approximation to the path integral is obtained, and shown to give the expected short-time behavior of the supertrace of the heat kernel.

  5. Precursory signatures of protein folding/unfolding: From time series correlation analysis to atomistic mechanisms

    SciTech Connect (OSTI)

    Hsu, P. J.; Lai, S. K., E-mail: sklai@coll.phy.ncu.edu.tw [Complex Liquids Laboratory, Department of Physics, National Central University, Chungli 320 Taiwan (China); Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan (China); Cheong, S. A. [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore)

    2014-05-28

    Folded conformations of proteins in thermodynamically stable states have long lifetimes. Before it folds into a stable conformation, or after unfolding from a stable conformation, the protein will generally stray from one random conformation to another leading thus to rapid fluctuations. Brief structural changes therefore occur before folding and unfolding events. These short-lived movements are easily overlooked in studies of folding/unfolding for they represent momentary excursions of the protein to explore conformations in the neighborhood of the stable conformation. The present study looks for precursory signatures of protein folding/unfolding within these rapid fluctuations through a combination of three techniques: (1) ultrafast shape recognition, (2) time series segmentation, and (3) time series correlation analysis. The first procedure measures the differences between statistical distance distributions of atoms in different conformations by calculating shape similarity indices from molecular dynamics simulation trajectories. The second procedure is used to discover the times at which the protein makes transitions from one conformation to another. Finally, we employ the third technique to exploit spatial fingerprints of the stable conformations; this procedure is to map out the sequences of changes preceding the actual folding and unfolding events, since strongly correlated atoms in different conformations are different due to bond and steric constraints. The aforementioned high-frequency fluctuations are therefore characterized by distinct correlational and structural changes that are associated with rate-limiting precursors that translate into brief segments. Guided by these technical procedures, we choose a model system, a fragment of the protein transthyretin, for identifying in this system not only the precursory signatures of transitions associated with ? helix and ? hairpin, but also the important role played by weaker correlations in such protein

  6. Universal collisional activation ion trap mass spectrometry

    DOE Patents [OSTI]

    McLuckey, Scott A.; Goeringer, Douglas E.; Glish, Gary L.

    1993-01-01

    A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

  7. Universal collisional activation ion trap mass spectrometry

    DOE Patents [OSTI]

    McLuckey, S.A.; Goeringer, D.E.; Glish, G.L.

    1993-04-27

    A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

  8. Ionization of polarized 3He+ ions in EBIS trap with slanted electrostatic mirror.

    SciTech Connect (OSTI)

    Pikin,A.; Zelenski, A.; Kponou, A.; Alessi, J.; Beebe, E.; Prelee, K.; Raparia, D.

    2007-09-10

    Methods of producing the nuclear polarized {sup 3}He{sup +} ions and their ionization to {sup 3}H{sup ++} in ion trap of the electron Beam Ion Source (EBIS) are discussed. Computer simulations show that injection and accumulation of {sup 3}He{sup +} ions in the EBIS trap with slanted electrostatic mirror can be very effective for injection times longer than the ion traversal time through the trap.

  9. Laser-driven Sisyphus cooling in an optical dipole trap

    SciTech Connect (OSTI)

    Ivanov, Vladyslav V.; Gupta, Subhadeep

    2011-12-15

    We propose a laser-driven Sisyphus-cooling scheme for atoms confined in a far-off resonance optical dipole trap. Utilizing the differential trap-induced ac Stark shift, two electronic levels of the atom are resonantly coupled by a cooling laser preferentially near the trap bottom. After absorption of a cooling photon, the atom loses energy by climbing the steeper potential, and then spontaneously decays preferentially away from the trap bottom. The proposed method is particularly suited to cooling alkaline-earth-metal-like atoms where two-level systems with narrow electronic transitions are present. Numerical simulations for the cases of {sup 88}Sr and {sup 174}Yb demonstrate the expected recoil and Doppler temperature limits. The method requires a relatively small number of scattered photons and can potentially lead to phase-space densities approaching quantum degeneracy in subsecond time scales.

  10. Time-local view of nonequilibrium statistical mechanics. II. Generalized Langevin equations

    SciTech Connect (OSTI)

    Der, R.

    1987-01-01

    On a semiphenomenological level, generalized Langevin equations are usually obtained by adding a random force (RF) term to macroscopic deterministic equations assumed to be known. Here this procedure is made rigorous by conveniently redefining the RF, which is shown to be colored noise weakly correlated with the observables at earlier times due to the finite lifetime of microscopic events. Corresponding fluctuation-dissipation theorems are derived. Explicit expressions for the spectral density of the fluctuations are obtained in a particularly simple form, with the deviation of the line shape from the Lorentzian being related most explicitly to the spectral density of the RF. Well-known low-frequency expressions and the Einstein relation of (generalized) Brownian motion theory are modified so as to include lifetime effects. New sum rules are obtained relating dissipative quantities to contour integrals (in the complex frequency domain) over spectral densities or corresponding response functions. The Heisenberg dynamics of a complete set of macroobservables is shown to be equivalent to a generalized Orstein-Uhlenbeck stochastic process which is a non-Markovian process due to the lifetime effects.

  11. Ion Trap Array-Based Systems And Methods For Chemical Analysis

    DOE Patents [OSTI]

    Whitten, William B [Oak Ridge, TN; Ramsey, J Michael [Knoxville, TN

    2005-08-23

    An ion trap-based system for chemical analysis includes an ion trap array. The ion trap array includes a plurality of ion traps arranged in a 2-dimensional array for initially confining ions. Each of the ion traps comprise a central electrode having an aperture, a first and second insulator each having an aperture sandwiching the central electrode, and first and second end cap electrodes each having an aperture sandwiching the first and second insulator. A structure for simultaneously directing a plurality of different species of ions out from the ion traps is provided. A spectrometer including a detector receives and identifies the ions. The trap array can be used with spectrometers including time-of-flight mass spectrometers and ion mobility spectrometers.

  12. Imaging electronic trap states in perovskite thin films with combined fluorescence and femtosecond transient absorption microscopy

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

    Xiao, Kai; Ma, Ying -Zhong; Simpson, Mary Jane; Doughty, Benjamin; Yang, Bin

    2016-04-22

    Charge carrier trapping degrades the performance of organometallic halide perovskite solar cells. To characterize the locations of electronic trap states in a heterogeneous photoactive layer, a spatially resolved approach is essential. Here, we report a comparative study on methylammonium lead tri-iodide perovskite thin films subject to different thermal annealing times using a combined photoluminescence (PL) and femtosecond transient absorption microscopy (TAM) approach to spatially map trap states. This approach coregisters the initially populated electronic excited states with the regions that recombine radiatively. Although the TAM images are relatively homogeneous for both samples, the corresponding PL images are highly structured. Themore » remarkable variation in the PL intensities as compared to transient absorption signal amplitude suggests spatially dependent PL quantum efficiency, indicative of trapping events. Furthermore, detailed analysis enables identification of two trapping regimes: a densely packed trapping region and a sparse trapping area that appear as unique spatial features in scaled PL maps.« less

  13. Observation of structural relaxation during exciton self-trapping via excited-state resonant impulsive stimulated Raman spectroscopy

    SciTech Connect (OSTI)

    Mance, J. G.; Felver, J. J.; Dexheimer, S. L.

    2015-02-28

    We detect the change in vibrational frequency associated with the transition from a delocalized to a localized electronic state using femtosecond vibrational wavepacket techniques. The experiments are carried out in the mixed-valence linear chain material [Pt(en){sub 2}][Pt(en){sub 2}Cl{sub 2}]⋅(ClO{sub 4}){sub 4} (en = ethylenediamine, C{sub 2}H{sub 8}N{sub 2}), a quasi-one-dimensional system with strong electron-phonon coupling. Vibrational spectroscopy of the equilibrated self-trapped exciton is carried out using a multiple pulse excitation technique: an initial pump pulse creates a population of delocalized excitons that self-trap and equilibrate, and a time-delayed second pump pulse tuned to the red-shifted absorption band of the self-trapped exciton impulsively excites vibrational wavepacket oscillations at the characteristic vibrational frequencies of the equilibrated self-trapped exciton state by the resonant impulsive stimulated Raman mechanism, acting on the excited state. The measurements yield oscillations at a frequency of 160 cm{sup −1} corresponding to a Raman-active mode of the equilibrated self-trapped exciton with Pt-Cl stretching character. The 160 cm{sup −1} frequency is shifted from the previously observed wavepacket frequency of 185 cm{sup −1} associated with the initially generated exciton and from the 312 cm{sup −1} Raman-active symmetric stretching mode of the ground electronic state. We relate the frequency shifts to the changes in charge distribution and local structure that create the potential that stabilizes the self-trapped state.

  14. The mechanisms for nanoparticle surface diffusion and chain self-assembly determined from real-time nanoscale kinetics in liquid

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

    Woehl, Taylor J.; Prozorov, Tanya

    2015-08-20

    The mechanisms for nanoparticle self-assembly are often inferred from the morphology of the final nanostructures in terms of attractive and repulsive interparticle interactions. Understanding how nanoparticle building blocks are pieced together during self-assembly is a key missing component needed to unlock new strategies and mechanistic understanding of this process. Here we use real-time nanoscale kinetics derived from liquid cell transmission electron microscopy investigation of nanoparticle self-assembly to show that nanoparticle mobility dictates the pathway for self-assembly and final nanostructure morphology. We describe a new method for modulating nanoparticle diffusion in a liquid cell, which we employ to systematically investigate themore » effect of mobility on self-assembly of nanoparticles. We interpret the observed diffusion in terms of electrostatically induced surface diffusion resulting from nanoparticle hopping on the liquid cell window surface. Slow-moving nanoparticles self-assemble predominantly into linear 1D chains by sequential attachment of nanoparticles to existing chains, while highly mobile nanoparticles self-assemble into chains and branched structures by chain–chain attachments. Self-assembly kinetics are consistent with a diffusion-driven mechanism; we attribute the change in self-assembly pathway to the increased self-assembly rate of highly mobile nanoparticles. Furthermore, these results indicate that nanoparticle mobility can dictate the self-assembly mechanism and final nanostructure morphology in a manner similar to interparticle interactions.« less

  15. The mechanisms for nanoparticle surface diffusion and chain self-assembly determined from real-time nanoscale kinetics in liquid

    SciTech Connect (OSTI)

    Woehl, Taylor J.; Prozorov, Tanya

    2015-08-20

    The mechanisms for nanoparticle self-assembly are often inferred from the morphology of the final nanostructures in terms of attractive and repulsive interparticle interactions. Understanding how nanoparticle building blocks are pieced together during self-assembly is a key missing component needed to unlock new strategies and mechanistic understanding of this process. Here we use real-time nanoscale kinetics derived from liquid cell transmission electron microscopy investigation of nanoparticle self-assembly to show that nanoparticle mobility dictates the pathway for self-assembly and final nanostructure morphology. We describe a new method for modulating nanoparticle diffusion in a liquid cell, which we employ to systematically investigate the effect of mobility on self-assembly of nanoparticles. We interpret the observed diffusion in terms of electrostatically induced surface diffusion resulting from nanoparticle hopping on the liquid cell window surface. Slow-moving nanoparticles self-assemble predominantly into linear 1D chains by sequential attachment of nanoparticles to existing chains, while highly mobile nanoparticles self-assemble into chains and branched structures by chain–chain attachments. Self-assembly kinetics are consistent with a diffusion-driven mechanism; we attribute the change in self-assembly pathway to the increased self-assembly rate of highly mobile nanoparticles. Furthermore, these results indicate that nanoparticle mobility can dictate the self-assembly mechanism and final nanostructure morphology in a manner similar to interparticle interactions.

  16. Have the best available trap on the job, check design, installation, and maintenance

    SciTech Connect (OSTI)

    Spires, F.; Toy, D.A.

    1986-12-01

    Industrial and commercial installations can have much more efficient steam systems with properly designed, installed, and maintained steam traps. Thirty years ago, steam trap maintenance did not have near the significance it does today; fuel costs have risen from about $0.30 per 1000 lb of steam to over 25 times that a few years ago to about 15 times that cost today. Worn or otherwise malfunctioning steam traps can take quite a toll on the energy bill, especially since most traps are designed to fail in the open position. Failure of just one steam trap with a 1/2'' diameter orifice in the open position can cost $45,090 a year. This article gives guidelines for the prevention of steam trap failures.

  17. Microfabricated linear Paul-Straubel ion trap

    DOE Patents [OSTI]

    Mangan, Michael A.; Blain, Matthew G.; Tigges, Chris P.; Linker, Kevin L.

    2011-04-19

    An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.

  18. Ion temperature gradient driven turbulence with strong trapped...

    Office of Scientific and Technical Information (OSTI)

    driven turbulence with strong trapped ion resonance is presented. The role of trapped ion granulations, clusters of trapped ions correlated by precession resonance, is the focus. ...

  19. Guide to Orifice Plate Steam Traps

    SciTech Connect (OSTI)

    Oland, C.B.

    2001-01-11

    This guide was prepared to serve as a foundation for making informed decisions about when orifice plate steam traps should be considered for use in new or existing steam systems. It presents background information about different types of steam traps and defines their unique functional and operational characteristics. The advantages and disadvantages associated with using orifice plate steam traps are provided to highlight their capabilities and limitations. Finally, recommendations for using orifice plate steam traps are presented, and possible applications are identified.

  20. Time-resolved x-ray diffraction and Raman studies of the phase transition mechanisms of methane hydrate

    SciTech Connect (OSTI)

    Hirai, Hisako Kadobayashi, Hirokazu; Hirao, Naohisa; Ohishi, Yasuo; Ohtake, Michika; Yamamoto, Yoshitaka; Nakano, Satoshi

    2015-01-14

    The mechanisms by which methane hydrate transforms from an sI to sH structure and from an sH to filled-ice Ih structure were examined using time-resolved X-ray diffractometry (XRD) and Raman spectroscopy in conjunction with charge-coupled device camera observation under fixed pressure conditions. The XRD data obtained for the sI–sH transition at 0.8 GPa revealed an inverse correlation between sI and sH, suggesting that the sI structure is replaced by sH. Meanwhile, the Raman analysis demonstrated that although the 12-hedra of sI are retained, the 14-hedra are replaced sequentially by additional 12-hedra, modified 12-hedra, and 20-hedra cages of sH. With the sH to filled-ice Ih transition at 1.8 GPa, both the XRD and Raman data showed that this occurs through a sudden collapse of the sH structure and subsequent release of solid and fluid methane that is gradually incorporated into the filled-ice Ih to complete its structure. This therefore represents a typical reconstructive transition mechanism.

  1. Scaling of volume to surface ratio and doubling time in growing unicellular organisms: Do cells appear quantum-mechanical systems?

    SciTech Connect (OSTI)

    Atanasov, Atanas Todorov

    2014-10-06

    The scaling of physical and biological characteristics of the living organisms is a basic method for searching of new biophysical laws. In series of previous studies the author showed that in Poikilotherms, Mammals and Aves, the volume to surface ratio VS{sup ?1} (m) of organisms is proportional to their generation time T{sub gt}(s) via growth rate v (m s{sup ?1}): VS{sup ?1}?=?v{sub gr}T{sup r}. The power and the correlation coefficients are near to 1.0. Aim of this study is: i) to prove with experimental data the validity of the above equation for Unicellular organisms and ii) to show that perhaps, the cells are quantum-mechanical systems. The data for body mass M (kg), density ? (kg/m{sup 3}), minimum and maximum doubling time T{sub dt} (s) for 50 unicellular organisms are assembled from scientific sources, and the computer program Statistics is used for calculations. In result i) the analytical relationship from type: VS{sup ?1}?=?4.46?10{sup ?11}T{sub dt} was found, where v{sub gr}?=?4.4610{sup ?11} m/s and ii) it is shown that the products between cell mass M, cell length expressed by V/S ratio and growth rate v{sub gr} satisfied the Heisenberg uncertainty principle i.e. the inequalities V/SMv{sub gr}>h/2? and T{sub dt}Mv{sub gr}{sup 2}>h/2? are valid, where h= 6.62610{sup ?34} J?s is the Planck constant. This rise the question: do cells appear quantum-mechanical systems?.

  2. Microscale ion trap mass spectrometer

    DOE Patents [OSTI]

    Ramsey, J. Michael; Witten, William B.; Kornienko, Oleg

    2002-01-01

    An ion trap for mass spectrometric chemical analysis of ions is delineated. The ion trap includes a central electrode having an aperture; a pair of insulators, each having an aperture; a pair of end cap electrodes, each having an aperture; a first electronic signal source coupled to the central electrode; a second electronic signal source coupled to the end cap electrodes. The central electrode, insulators, and end cap electrodes are united in a sandwich construction where their respective apertures are coaxially aligned and symmetric about an axis to form a partially enclosed cavity having an effective radius r.sub.0 and an effective length 2z.sub.0, wherein r.sub.0 and/or z.sub.0 are less than 1.0 mm, and a ratio z.sub.0 /r.sub.0 is greater than 0.83.

  3. Quantum chaos of an ion trapped in a linear ion trap

    SciTech Connect (OSTI)

    Berman, Gennady P. [Theoretical Division T-13, and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division T-13, and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); James, Daniel F. V. [Theoretical Division T-4, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division T-4, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kamenev, Dimitri I. [Theoretical Division T-13, and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) [Theoretical Division T-13, and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Nizhny Novgorod State University, Nizhny Novgorod, 603600, Russia (Russian Federation)

    2000-06-01

    We describe the transition to quantum chaos of an ion trapped in a linear ion trap and interacting with two laser fields. Under the conditions of adiabatic illumination of the upper level of the ion, and when the frequencies of the two laser beams are slightly different, the system is reduced to a quantum linear oscillator interacting with a monochromatic wave. The property of localization over the quantum resonance cells is proposed to exploit in order to facilitate the process of measurement of the probability distribution of an ion on the vibrational levels. In the regime of strong chaos the time-averaged values of the energy and dispersion of energy are computed and compared with the corresponding classical quantities for different values of the perturbation amplitude. In the exact resonance case, the classical analog of the system possesses an infinite inhomogeneous stochastic web. We analyze the quantum dynamics inside the inhomogeneous web. It is shown that the quantum system mimics on average the dynamics of the corresponding classical system. Formation of the quantum resonance cells is illustrated in the case of a finite detuning from the exact resonance, and under increasing of the wave amplitude. The parameters of the model and the initial conditions are close to the real physical situation which can be realized in the system of cold trapped ion perturbed by two lasers fields with close frequencies. (c) 2000 American Institute of Physics.

  4. Hybrid particle traps and conditioning procedure for gas insulated transmission lines

    DOE Patents [OSTI]

    Dale, Steinar J.; Cookson, Alan H.

    1982-01-01

    A gas insulated transmission line includes an outer sheath, an inner condor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping ring is disposed within the outer sheath, and the trapping ring has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the trapping ring along an arc. A support sheet having an adhesive coating thereon is secured to the trapping ring and disposed on the outer sheath within the low field region formed between the trapping ring and the outer sheath. A conditioning method used to condition the transmission line prior to activation in service comprises applying an AC voltage to the inner conductor in a plurality of voltage-time steps, with the voltage-time steps increasing in voltage magnitude while decreasing in time duration.

  5. Ion traps fabricated in a CMOS foundry

    SciTech Connect (OSTI)

    Mehta, K. K.; Ram, R. J.; Eltony, A. M.; Chuang, I. L.; Bruzewicz, C. D.; Sage, J. M. Chiaverini, J.

    2014-07-28

    We demonstrate trapping in a surface-electrode ion trap fabricated in a 90-nm CMOS (complementary metal-oxide-semiconductor) foundry process utilizing the top metal layer of the process for the trap electrodes. The process includes doped active regions and metal interconnect layers, allowing for co-fabrication of standard CMOS circuitry as well as devices for optical control and measurement. With one of the interconnect layers defining a ground plane between the trap electrode layer and the p-type doped silicon substrate, ion loading is robust and trapping is stable. We measure a motional heating rate comparable to those seen in surface-electrode traps of similar size. This demonstration of scalable quantum computing hardware utilizing a commercial CMOS process opens the door to integration and co-fabrication of electronics and photonics for large-scale quantum processing in trapped-ion arrays.

  6. Electrostatic particle trap for ion beam sputter deposition ...

    Office of Scientific and Technical Information (OSTI)

    The electrostatic particle trap consists of an array of electrode surfaces, each ... particle; trap; consists; array; electrode; surfaces; maintained; electrostatic; ...

  7. Production of Ultracold Trapped Molecular Hydrogen Ions

    SciTech Connect (OSTI)

    Blythe, P.; Roth, B.; Froehlich, U.; Wenz, H.; Schiller, S.

    2005-10-28

    We have cooled ensembles of the molecular hydrogen ions H{sub 2}{sup +}, H{sub 3}{sup +}, and all their deuterated variants to temperatures of a few mK in a radio frequency trap, by sympathetic cooling with laser-cooled beryllium ions. The molecular ions are embedded in the central regions of Coulomb crystals. Mass spectroscopy and molecular dynamics simulations were used to accurately characterize the properties of the ultracold multispecies crystals. We demonstrate species-selective purification of multispecies ensembles. These molecules are of fundamental importance as the simplest of all molecules, and have the potential to be used for precision tests of molecular structure theory, tests of Lorentz invariance, and measurements of electron to nuclear mass ratios and their time variation.

  8. Qualitative analysis of trapped Dirac fermions in graphene

    SciTech Connect (OSTI)

    Jakubsk, Vt Krej?i?k, David

    2014-10-15

    We study the confinement of Dirac fermions in graphene and in carbon nanotubes by an external magnetic field, mechanical deformations or inhomogeneities in the substrate. By applying variational principles to the square of the Dirac operator, we obtain sufficient and necessary conditions for confinement of the quasi-particles. The rigorous theoretical results are illustrated on the realistic examples of the three classes of traps.

  9. Trapping of intense light in hollow shell

    SciTech Connect (OSTI)

    Luan, Shixia; Yu, Wei; Yu, M. Y.; Weng, Suming; Wang, Jingwei; Xu, Han; Zhuo, Hongbin; Wong, A. Y.

    2015-09-15

    A small hollow shell for trapping laser light is proposed. Two-dimensional particle-in-cell simulation shows that under appropriate laser and plasma conditions a part of the radiation fields of an intense short laser pulse can enter the cavity of a small shell through an over-critical density plasma in an adjacent guide channel and become trapped. The trapped light evolves into a circulating radial wave pattern until its energy is dissipated.

  10. Measurements of PM Traps | Department of Energy

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

    Measurements of PM Traps 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentantion: West Virginia University PDF icon 2004deerclark.pdf More Documents & Publications ...

  11. Shale gas is natural gas trapped inside

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

    Shale gas is natural gas trapped inside formations of shale - fine grained sedimentary ... Fossil Energy Research Benefits FE's early investments in shale research in the 1970s ...

  12. Cavity sideband cooling of trapped molecules

    SciTech Connect (OSTI)

    Kowalewski, Markus; Vivie-Riedle, Regina de [Department of Chemistry, Ludwig-Maximilian-Universitaet, D-81377 Munich (Germany); Morigi, Giovanna [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Theoretische Physik, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany); Pinkse, Pepijn W. H. [MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede (Netherlands)

    2011-09-15

    The efficiency of cavity sideband cooling of trapped molecules is theoretically investigated for the case in which the infrared transition between two rovibrational states is used as a cycling transition. The molecules are assumed to be trapped either by a radiofrequency or optical trapping potential, depending on whether they are charged or neutral, and confined inside a high-finesse optical resonator that enhances radiative emission into the cavity mode. Using realistic experimental parameters and COS as a representative molecular example, we show that in this setup, cooling to the trap ground state is feasible.

  13. Dipole Excitation With A Paul Ion Trap Mass Spectrometer

    SciTech Connect (OSTI)

    MacAskill, J. A.; Madzunkov, S. M.; Chutjian, A.

    2011-06-01

    Preliminary results are presented for the use of an auxiliary radiofrequency (rf) excitation voltage in combination with a high purity, high voltage rf generator to perform dipole excitation within a high precision Paul ion trap. These results show the effects of the excitation frequency over a continuous frequency range on the resultant mass spectra from the Paul trap with particular emphasis on ion ejection times, ion signal intensity, and peak shapes. Ion ejection times are found to decrease continuously with variations in dipole frequency about several resonant values and show remarkable symmetries. Signal intensities vary in a complex fashion with numerous resonant features and are driven to zero at specific frequency values. Observed intensity variations depict dipole excitations that target ions of all masses as well as individual masses. Substantial increases in mass resolution are obtained with resolving powers for nitrogen increasing from 114 to 325.

  14. Electron Traps In p-Type GaAsN Characterized by Deep-Level Transient Spectroscopy

    SciTech Connect (OSTI)

    Johnston, S. W.; Kurtz, S.; Friedman, D. J.; Ptak, A. J.; Ahrenkiel, R. K.; Crandall, R. S.

    2005-02-01

    We have used deep-level transient spectroscopy to detect traps in p-type GaAsN grown by metal-organic chemical vapor deposition. Although minority-carrier electrons are not intentionally injected into the depletion region of the measured samples, electron traps are detected in both Schottky barrier and p-n junction devices. The electron-trap signal can exist using only reverse biases during measurement, and checks of series resistance and minority-carrier injection using an optical source also confirm the electron-trap signal. For dilute-nitrogen p-n junction samples, the electron trap gives the dominant signal peak. The peak's magnitude, which corresponds to trap density, correlates to amounts of nitrogen incorporated during growth and reduced open-circuit voltage during light characterization. The p-type GaAsN layers have net acceptor carrier concentrations in the mid-1016 to low-1017 cm-3, as determined by capacitance-voltage profiling. The electron-trap concentration depends on the N content, but values, when traps are filled to saturation, range from 1015 to 1016 cm-3. The electron signal peak shows a shoulder peak on some samples, giving another close energy level. The electron-trap activation energy is somewhat dependent on the trap filling time, but ranges from about 0.15 to 0.30 eV, and is usually near 0.2 eV for the largest peak when filled to saturation.

  15. The Paul Trap Simulator Experiment (PTSX) | Princeton Plasma...

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

    The Paul Trap Simulator Experiment (PTSX) The Paul Trap Simulator Experiment (PTSX) at the U.S. Department of Energy's Princeton Plasma Physics Laboratory doesn't trap people named...

  16. Fuel traps: mapping stability via water association.

    SciTech Connect (OSTI)

    Rempe, Susan L.; Clawson, Jacalyn S.; Greathouse, Jeffery A.; Alam, Todd M; Leung, Kevin; Varma, Sameer; Sabo, Dubravko; Martin, Marcus Gary; Cygan, Randall Timothy

    2007-03-01

    Hydrogen storage is a key enabling technology required for attaining a hydrogen-based economy. Fundamental research can reveal the underlying principles controlling hydrogen uptake and release by storage materials, and also aid in characterizing and designing novel storage materials. New ideas for hydrogen storage materials come from exploiting the properties of hydrophobic hydration, which refers to water s ability to stabilize, by its mode of association, specific structures under specific conditions. Although hydrogen was always considered too small to support the formation of solid clathrate hydrate structures, exciting new experiments show that water traps hydrogen molecules at conditions of low temperatures and moderate pressures. Hydrogen release is accomplished by simple warming. While these experiments lend credibility to the idea that water could form an environmentally attractive alternative storage compound for hydrogen fuel, which would advance our nation s goals of attaining a hydrogen-based economy, much work is yet required to understand and realize the full potential of clathrate hydrates for hydrogen storage. Here we undertake theoretical studies of hydrogen in water to establish a firm foundation for predictive work on clathrate hydrate H{sub 2} storage capabilities. Using molecular simulation and statistical mechanical theories based in part on quantum mechanical descriptions of molecular interactions, we characterize the interactions between hydrogen and liquid water in terms of structural and thermodynamic properties. In the process we validate classical force field models of hydrogen in water and discover new features of hydrophobic hydration that impact problems in both energy technology and biology. Finally, we predict hydrogen occupancy in the small and large cages of hydrogen clathrate hydrates, a property unresolved by previous experimental and theoretical work.

  17. Investigation of Aging Mechanisms in Lean NOx Traps

    Broader source: Energy.gov [DOE]

    2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C.

  18. Benchmark Reaction Mechanisms and Kinetics for Lean NOx Traps | Department

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

    Bench Scale Integration WBS 2.4.1.100 2015 DOE BioEnergy Technologies Office (BETO) Project Peer Review Date: March 25, 2015 Technology Area Review: Biochemical Conversion Principal Investigator: Nancy Dowe (Rick Elander, presenter) Organization: National Renewable Energy Laboratory This presentation does not contain any proprietary, confidential, or otherwise restricted information 2 Goal Statement Goal is to demonstrate, at bench scale, an integrated process to produce HC fuel and a model

  19. Benchmark Reaction Mechanisms and Kinetics for Lean NOx Traps...

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

    and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. PDF icon acep01larson.pdf More Documents & Publications Development of Chemical Kinetic Models for Lean NOx ...

  20. Rare-earth neutral metal injection into an electron beam ion trap plasma

    SciTech Connect (OSTI)

    Magee, E. W., E-mail: magee1@llnl.gov; Beiersdorfer, P.; Brown, G. V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hell, N. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Dr. Remeis-Sternwarte and ECAP, Universitt Erlangen-Nrnberg, 96049 Bamberg (Germany)

    2014-11-15

    We have designed and implemented a neutral metal vapor injector on the SuperEBIT high-energy electron beam ion trap at the Lawrence Livermore National Laboratory. A horizontally directed vapor of a europium metal is created using a thermal evaporation technique. The metal vapor is then spatially collimated prior to injection into the trap. The source's form and quantity constraints are significantly reduced making plasmas out of metal with vapor pressures ?10{sup ?7} Torr at ?1000?C more obtainable. A long pulsed or constant feed metal vapor injection method adds new flexibility by varying the timing of injection and rate of material being introduced into the trap.

  1. Optical trapping and rotation of airborne absorbing particles with a single focused laser beam

    SciTech Connect (OSTI)

    Lin, Jinda; Li, Yong-qing, E-mail: liy@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)] [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)

    2014-03-10

    We measure the periodic circular motion of single absorbing aerosol particles that are optically trapped with a single focused Gaussian beam and rotate around the laser propagation direction. The scattered light from the trapped particle is observed to be directional and change periodically at 0.420?kHz. The instantaneous positions of the moving particle within a rotation period are measured by a high-speed imaging technique using a charge coupled device camera and a repetitively pulsed light-emitting diode illumination. The centripetal acceleration of the trapped particle as high as ?20 times the gravitational acceleration is observed and is attributed to the photophoretic forces.

  2. Production and Trapping of Ultracold Polar Molecules

    SciTech Connect (OSTI)

    David, DeMille

    2015-04-21

    We report a set of experiments aimed at the production and trapping of ultracold polar molecules. We begin with samples of laser-cooled and trapped Rb and Cs atoms, and bind them together to form polar RbCs molecules. The binding is accomplished via photoassociation, which uses a laser to catalyze the sticking process. We report results from investigation of a new pathway for photoassociation that can produce molecules in their absolute ground state of vibrational and rotational motion. We also report preliminary observations of collisions between these ground-state molecules and co-trapped atoms.

  3. Requirements-Driven Diesel Catalyzed Particulate Trap Design...

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

    Requirements-Driven Diesel Catalyzed Particulate Trap Design and Optimization Requirements-Driven Diesel Catalyzed Particulate Trap Design and Optimization 2005 Diesel Engine ...

  4. Bear Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Bear Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility Facility Bear...

  5. NAC 503 - Hunting, Fishing and Trapping | Open Energy Information

    Open Energy Info (EERE)

    Fishing and TrappingLegal Abstract These code sections outline the protective measures and restrictions on hunting, fishing, and trapping in the state of Nevada. Published...

  6. Inspect and Repair Steam Traps, Energy Tips: STEAM, Steam Tip...

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

    ... There are four basic ways to test steam traps: temperature, sound, visual, and electronic. Recommended Steam Trap Testing Intervals * High-Pressure (150 psig and above): Weekly to ...

  7. Trapped Ion Optical Clocks at NPL

    SciTech Connect (OSTI)

    Margolis, H. S.; Barwood, G. P.; Hosaka, K.; Klein, H. A.; Lea, S. N.; Walton, B. R.; Webster, S. A.; Gill, P.; Huang, G.; Stannard, A.

    2006-11-07

    Forbidden transitions in single laser-cooled trapped ions provide highly stable and accurate references for optical frequency standards. This paper describes recent progress on strontium and ytterbium ion optical frequency standards under development at NPL.

  8. Barrier to Trap Filling CuIn1-xGaxSe2: Preprint

    SciTech Connect (OSTI)

    Young, D. L.; Ramanathan, K.; Contreras, M.; Abushama, J.; Crandall, R. S.

    2003-04-01

    Voltage pulses of variable length were applied to CuIn1-xGaxSe2/CdS (0< x< 1) junction solar cells. The resulting transient capacitance emission signal was recorded for several minutes. The amplitude of the capacitance emission signal increased linearly with the log of pulse time. These data do not follow the standard model for trap capture and emission of carriers. Instead they follow a simple electrostatic model based on electrostatic charging of traps.

  9. Protection #2: Trap and Remove Sediment

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

    Trap and Remove Sediment Protection #2: Trap and Remove Sediment The 3 Protections = Defense in Depth August 1, 2013 Sediment behind LA Canyon weir is sampled and excavated regularly. As of 2012, no sediment required disposal as hazardous or radioactive waste. Sediment behind LA Canyon weir is sampled and excavated regularly. As of 2012, no sediment required disposal as hazardous or radioactive waste. The 3 Protections Protection #1: Remove the source of contamination Protection #2: Stabilize,

  10. Selective interactions in trapped ions: State reconstruction and quantum logic

    SciTech Connect (OSTI)

    Solano, E.

    2005-01-01

    We propose the implementation of selective interactions of atom-motion subspaces in trapped ions. These interactions yield resonant exchange of population inside a selected subspace, leaving the others in a highly dispersive regime. Selectivity allows us to generate motional Fock (and other nonclassical) states with high purity out of a wide class of initial states, and becomes an unconventional cooling mechanism when the ground state is chosen. Individual population of number states can be distinctively measured, as well as the motional Wigner function. Furthermore, a protocol for implementing quantum logic through a suitable control of selective subspaces is presented.

  11. The effects of deep level traps on the electrical properties of semi-insulating CdZnTe

    SciTech Connect (OSTI)

    Zha, Gangqiang; Yang, Jian; Xu, Lingyan; Feng, Tao; Wang, Ning; Jie, Wanqi

    2014-01-28

    Deep level traps have considerable effects on the electrical properties and radiation detection performance of high resistivity CdZnTe. A deep-trap model for high resistivity CdZnTe was proposed in this paper. The high resistivity mechanism and the electrical properties were analyzed based on this model. High resistivity CdZnTe with high trap ionization energy E{sub t} can withstand high bias voltages. The leakage current is dependent on both the deep traps and the shallow impurities. The performance of a CdZnTe radiation detector will deteriorate at low temperatures, and the way in which sub-bandgap light excitation could improve the low temperature performance can be explained using the deep trap model.

  12. Nano-chemo-mechanical signature of conventional oil-well cement systems: Effects of elevated temperature and curing time

    SciTech Connect (OSTI)

    Krakowiak, Konrad J.; Thomas, Jeffrey J.; Musso, Simone; James, Simon; Akono, Ange-Therese; Ulm, Franz-Josef

    2015-01-15

    With ever more challenging (T,p) environments for cementing applications in oil and gas wells, there is a need to identify the fundamental mechanisms of fracture resistant oil well cements. We report results from a multi-technique investigation of behavior and properties of API class G cement and silica-enriched cement systems subjected to hydrothermal curing from 30 °C to 200 °C; including electron probe microanalysis, X-ray diffraction, thermogravimetry analysis, electron microscopy, neutron scattering (SANS), and fracture scratch testing. The results provide a new insight into the link between system chemistry, micro-texture and micro-fracture toughness. We suggest that the strong correlation found between chemically modulated specific surface and fracture resistance can explain the drop in fracture properties of neat oil-well cements at elevated temperatures; the fracture property enhancement in silica-rich cement systems, between 110° and 175 °C; and the drop in fracture properties of such systems through prolonged curing over 1 year at 200 °C.

  13. Location Of Hole And Electron Traps On Nanocrystalline Anatase TiO2

    SciTech Connect (OSTI)

    Mercado, Candy C.; Knorr, Fritz J.; McHale, Jeanne L.; Usmani, Shirin M.; Ichimura, Andrew S.; Saraf, Laxmikant V.

    2012-05-17

    The defect photoluminescence from TiO2 nanoparticles in the anatase phase is reported for nanosheets which expose predominantly (001) surfaces, and compared to that from conventional anatase nanoparticles which expose mostly (101) surfaces. Also reported is the weak defect photoluminescence of TiO2 nanotubes, which we find using electron back-scattered diffraction to consist of walls which expose (110) and (100) facets. The nanotubes exhibit photoluminescence that is blue-shifted and much weaker than that from conventional TiO2 nanoparticles. Despite the preponderance of (001) surfaces in the nanosheet samples, they exhibit photoluminescence similar to that of conventional nanoparticles. We assign the broad visible photoluminescence of anatase nanoparticles to two overlapping distributions: hole trap emission associated with oxygen vacancies on (101) exposed surfaces, which peaks in the green, and a broader emission extending into the red which results from electron traps on under-coordinated titanium atoms, which are prevalent on (001) facets. The results of this study suggest how morphology of TiO2 nanoparticles could be optimized to control the distribution and activity of surface traps. Our results also shed light on the mechanism by which the TiCl4 surface treatment heals traps on anatase and mixed-phase TiO2 films, and reveals distinct differences in the trap-state distributions of TiO2 nanoparticles and nanotubes. The molecular basis for electron and hole traps and their spatial separation on different facets is discussed.

  14. Review of Orifice Plate Steam Traps | Department of Energy

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

    Orifice Plate Steam Traps Review of Orifice Plate Steam Traps This guide was prepared to serve as a foundation for making informed decisions about when orifice plate steam traps should be considered for use in new or existing steam systems. It presents background information about different types of steam traps and defines their unique functional and operational characteristics. The advantages and disadvantages associated with using orifice plate steam traps are provided to highlight their

  15. Development of Metal Substrate for Denox Catalysts and Particulate Trap

    SciTech Connect (OSTI)

    Pollard, Michael; Habeger, Craig; Frary, Megan; Haines, Scott; Fluharty, Amy; Dakhoul, Youssef; Carr, Michael; Park, Paul; Stefanick, Matthew; DaCosta, Herbert; Balmer-Millar, M Lou; Readey, Michael; McCluskey, Philip

    2005-12-31

    The objective of this project was to develop advanced metallic catalyst substrate materials and designs for use in off-highway applications. The new materials and designs will be used as catalyst substrates and diesel particulate traps. They will increase durability, reduce flow resistance, decrease time to light-off, and reduce cost relative to cordierite substrates. Metallic catalyst substrates are used extensively for diesel oxidation catalysts and have the potential to be used in other catalytic systems for diesel engines. Metallic substrates have many advantages over ceramic materials including improved durability and resistance to thermal shock and vibration. However, the cost is generally higher than cordierite. The most common foil material used for metallic substrates is FeCr Alloy, which is expensive and has temperature capabilities beyond what is necessary for diesel applications. The first task in the project was Identification and Testing of New Materials. In this task, several materials were analyzed to determine if a low cost substitute for FeCr Alloy was available or could be developed. Two materials were identified as having lower cost while showing no decrease in mechanical properties or oxidation resistance at the application temperatures. Also, the ability to fabricate these materials into a finished substrate was not compromised, and the ability to washcoat these materials was satisfactory. Therefore, both candidate materials were recommended for cost savings depending on which would be less expensive in production quantities. The second task dealt with the use of novel flow designs to improve the converter efficiency while possibly decreasing the size of the converter to reduce cost even more. A non-linear flow path was simulated to determine if there would be an increase in efficiency. From there, small samples were produced for bench testing. Bench tests showed that the use of non-linear channels significantly reduced the light

  16. Signal enhancement using a switchable magnetic trap

    DOE Patents [OSTI]

    Beer, Neil Reginald

    2012-05-29

    A system for analyzing a sample including providing a microchannel flow channel; associating the sample with magnetic nanoparticles or magnetic polystyrene-coated beads; moving the sample with said magnetic nanoparticles or magnetic polystyrene-coated beads in the microchannel flow channel; holding the sample with the magnetic nanoparticles or magnetic polystyrene-coated beads in a magnetic trap in the microchannel flow channel; and analyzing the sample obtaining an enhanced analysis signal. An apparatus for analysis of a sample includes magnetic particles connected to the sample, a microchip, a flow channel in the microchip, a source of carrier fluid connected to the flow channel for moving the sample in the flow channel, an electromagnet trap connected to the flow line for selectively magnetically trapping the sample and the magnetic particles, and an analyzer for analyzing the sample.

  17. Screening the Hanford tanks for trapped gas

    SciTech Connect (OSTI)

    Whitney, P.

    1995-10-01

    The Hanford Site is home to 177 large, underground nuclear waste storage tanks. Hydrogen gas is generated within the waste in these tanks. This document presents the results of a screening of Hanford`s nuclear waste storage tanks for the presence of gas trapped in the waste. The method used for the screening is to look for an inverse correlation between waste level measurements and ambient atmospheric pressure. If the waste level in a tank decreases with an increase in ambient atmospheric pressure, then the compressibility may be attributed to gas trapped within the waste. In this report, this methodology is not used to estimate the volume of gas trapped in the waste. The waste level measurements used in this study were made primarily to monitor the tanks for leaks and intrusions. Four measurement devices are widely used in these tanks. Three of these measure the level of the waste surface. The remaining device measures from within a well embedded in the waste, thereby monitoring the liquid level even if the liquid level is below a dry waste crust. In the past, a steady rise in waste level has been taken as an indicator of trapped gas. This indicator is not part of the screening calculation described in this report; however, a possible explanation for the rise is given by the mathematical relation between atmospheric pressure and waste level used to support the screening calculation. The screening was applied to data from each measurement device in each tank. If any of these data for a single tank indicated trapped gas, that tank was flagged by this screening process. A total of 58 of the 177 Hanford tanks were flagged as containing trapped gas, including 21 of the 25 tanks currently on the flammable gas watch list.

  18. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, Terry (Tracy, CA)

    1988-01-01

    A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself.

  19. Entanglement of trapped-ion clock states

    SciTech Connect (OSTI)

    Haljan, P. C.; Lee, P. J.; Brickman, K-A.; Acton, M.; Deslauriers, L.; Monroe, C.

    2005-12-15

    A Moelmer-Soerensen entangling gate is realized for pairs of trapped {sup 111}Cd{sup +} ions using magnetic-field insensitive 'clock' states and an implementation offering reduced sensitivity to optical phase drifts. The gate is used to generate the complete set of four entangled states, which are reconstructed and evaluated with quantum-state tomography. An average target-state fidelity of 0.79 is achieved, limited by available laser power and technical noise. The tomographic reconstruction of entangled states demonstrates universal quantum control of two ion qubits, which through multiplexing can provide a route to scalable architectures for trapped-ion quantum computing.

  20. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, T.

    1988-03-15

    A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself. 4 figs.

  1. Ball-grid array architecture for microfabricated ion traps

    SciTech Connect (OSTI)

    Guise, Nicholas D. Fallek, Spencer D.; Stevens, Kelly E.; Brown, K. R.; Volin, Curtis; Harter, Alexa W.; Amini, Jason M.; Higashi, Robert E.; Lu, Son Thai; Chanhvongsak, Helen M.; Nguyen, Thi A.; Marcus, Matthew S.; Ohnstein, Thomas R.; Youngner, Daniel W.

    2015-05-07

    State-of-the-art microfabricated ion traps for quantum information research are approaching nearly one hundred control electrodes. We report here on the development and testing of a new architecture for microfabricated ion traps, built around ball-grid array (BGA) connections, that is suitable for increasingly complex trap designs. In the BGA trap, through-substrate vias bring electrical signals from the back side of the trap die to the surface trap structure on the top side. Gold-ball bump bonds connect the back side of the trap die to an interposer for signal routing from the carrier. Trench capacitors fabricated into the trap die replace area-intensive surface or edge capacitors. Wirebonds in the BGA architecture are moved to the interposer. These last two features allow the trap die to be reduced to only the area required to produce trapping fields. The smaller trap dimensions allow tight focusing of an addressing laser beam for fast single-qubit rotations. Performance of the BGA trap as characterized with {sup 40}Ca{sup +} ions is comparable to previous surface-electrode traps in terms of ion heating rate, mode frequency stability, and storage lifetime. We demonstrate two-qubit entanglement operations with {sup 171}Yb{sup +} ions in a second BGA trap.

  2. Effect of dislocation trapping on deuterium diffusion in deformed, single-crystal Pd

    SciTech Connect (OSTI)

    Heuser, B.J.; King, J.S.

    1998-06-01

    Small-angle neutron scattering (SANS) has been used to characterize deuterium trapping at dislocations in deformed, single-crystal Pd during in situ gas evolution experiments. Two methods of deformation were employed--cold rolling and hydride cycling--which create different dislocation arrangements or substructures in Pd. The reduction of the trapped deuterium concentration at dislocations during evolution was directly monitored with SANS. Exponential decay rates of the trapped concentration were observed for both sample types, as is expected in a bulk diffusion process modified by the dislocation trapping interaction. The deuterium concentration reduction proceeded 1.2 to 1.4 times faster in the cold-rolled sample material than in the cycled material. This is attributed to the presence of a smaller number of dislocation trapping sites in the cold-rolled material. The binding energy of deuterium at dislocations was determined by applying a diffusion-based model. A binding energy of 0.20 eV was found to characterize the trapping interaction in both cold-rolled and hydride-cycled Pd.

  3. Bucket-type steam traps removed in $82K retrofit

    SciTech Connect (OSTI)

    Poplett, J.

    1985-08-19

    A retrofit of 481 mostly failed steam traps at Martin Marietta's Aerospace Division should reduce steam costs by $70,000 and require little or no maintenance. Payback should occur within 14 months. The new traps include orifice, bellow-type thermostatic, and float-type traps that have few or no moving parts. Lack of maintenance was responsible for the poor performance of the bucket traps that were replaced, although manufacturers of the bucket traps disagree that replacement of certain parts is necessary every six months. The author describes the design and operation of each type of trap.

  4. Resonant trapping in the transport of a matter-wave soliton through a quantum well

    SciTech Connect (OSTI)

    Ernst, Thomas; Brand, Joachim

    2010-03-15

    We theoretically investigate the scattering of bright solitons in a Bose-Einstein condensate on narrow attractive potential wells. Reflection, transmission, and trapping of an incident soliton are predicted to occur with remarkably abrupt transitions upon varying the potential depth. Numerical simulations of the nonlinear Schroedinger equation are complemented by a variational collective coordinate approach. The mechanism for nonlinear trapping is found to rely both on resonant interaction between the soliton and bound states in the potential well and on the radiation of small-amplitude waves. These results suggest that solitons can be used to probe bound states that are not accessible through scattering with single atoms.

  5. Efficient nanorod-based amorphous silicon solar cells with advanced light trapping

    SciTech Connect (OSTI)

    Kuang, Y.; Lare, M. C. van; Polman, A.; Veldhuizen, L. W.; Schropp, R. E. I.; Rath, J. K.

    2015-11-14

    We present a simple, low-cost, and scalable approach for the fabrication of efficient nanorod-based solar cells. Templates with arrays of self-assembled ZnO nanorods with tunable morphology are synthesized by chemical bath deposition using a low process temperature at 80 °C. The nanorod templates are conformally coated with hydrogenated amorphous silicon light absorber layers of 100 nm and 200 nm thickness. An initial efficiency of up to 9.0% is achieved for the optimized design. External quantum efficiency measurements on the nanorod cells show a substantial photocurrent enhancement both in the red and the blue parts of the solar spectrum. Key insights in the light trapping mechanisms in these arrays are obtained via a combination of three-dimensional finite-difference time-domain simulations, optical absorption, and external quantum efficiency measurements. Front surface patterns enhance the light incoupling in the blue, while rear side patterns lead to enhanced light trapping in the red. The red response in the nanorod cells is limited by absorption in the patterned Ag back contact. With these findings, we develop and experimentally realize a further advanced design with patterned front and back sides while keeping the Ag reflector flat, showing significantly enhanced scattering from the back reflector with reduced parasitic absorption in the Ag and thus higher photocurrent generation. Many of the findings in this work can serve to provide insights for further optimization of nanostructures for thin-film solar cells in a broad range of materials.

  6. Controlling soliton interactions in Bose-Einstein condensates by synchronizing the Feshbach resonance and harmonic trap

    SciTech Connect (OSTI)

    Zhang Xiaofei |; Yang Qin |; Zhang Jiefang; Chen, X. Z.; Liu, W. M.

    2008-02-15

    We present how to control interactions between solitons, either bright or dark, in Bose-Einstein condensates by synchronizing Feshbach resonance and harmonic trap. Our results show that as long as the scattering length is to be modulated in time via a changing magnetic field near the Feshbach resonance, and the harmonic trapping frequencies are also modulated in time, exact solutions of the one-dimensional nonlinear Schroedinger equation can be found in a general closed form, and interactions between two solitons are modulated in detail in currently experimental conditions. We also propose experimental protocols to observe the phenomena such as fusion, fission, warp, oscillation, elastic collision in future experiments.

  7. Characterization of trapped gas saturation and heterogeneity in core sampling using miscible-displacement experiments

    SciTech Connect (OSTI)

    Smith, D.H.; Jikich, S.A.

    1994-12-31

    Trapped gas saturation and permeability heterogeneity were evaluated in Berea cores at reservoir conditions, using standard miscible displacement experiments, with and without surfactants. Pressure and production history were influenced by core heterogeneity and foam lamellae formation when aqueous surfactant was present in the core. The objective of the dispersion-capacitance model was to estimate trapped gas saturations; however longitudinal dispersion and mass transfer also were examined. The results show that the dispersion-capacitance model accurately fits trapped gas saturation controlled by rock heterogeneities and foam lamellae for lamella generating mechanisms that allow a continuous gas phase (leave-behind lamellae). The practical applications resulting from this study can aid in core sample selection and scaling short laboratory corefloods to field dimensions for applications to foam stimulation and underground storage of natural gas.

  8. Importance of hydrophobic traps for proton diffusion in lyotropic liquid crystals

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

    McDaniel, Jesse G.; Yethiraj, Arun

    2016-03-04

    The diffusion of protons in self-assembled systems is potentially important for the design of efficient proton exchange membranes. In this work, we study proton dynamics in a low-water content, lamellar phase of an sodium-carboxylate gemini surfactant/water system using computer simulations. The hopping of protons via the Grotthuss mechanism is explicity allowed through the multi-state empirical valence bond (MS-EVB) method. We find that the hydronium ion is trapped on the hydrophobic side of the surfactant-water interface, and proton diffusion then proceeds by hopping between surface sites. The importance of hydrophobic traps is surprising, because one would expect the hydronium ions tomore » be trapped at the charged head-groups. Finally, the physics illustrated in this system should be relevant to the proton dynamics in other amphiphilic membrane systems, whenever there exists exposed hydrophobic surface regions.« less

  9. Multi-particle trapping and manipulation by a high-frequency array transducer

    SciTech Connect (OSTI)

    Yoon, Changhan; Kang, Bong Jin; Lee, Changyang; Kim, Hyung Ham Shung, K. Kirk

    2014-11-24

    We report the multiple micro-particle trapping and manipulation by a single-beam acoustic tweezer using a high-frequency array transducer. A single acoustic beam generated by a 30 MHz ultrasonic linear array transducer can entrap and transport multiple micro-particles located at the main lobe and the grating lobes. The distance between trapped particles can be adjusted by changing the transmit arrangement of array-based acoustic tweezers and subsequently the location of grating lobes. The experiment results showed that the proposed method can trap and manipulate multiple particles within a range of hundreds of micrometers. Due to its simplicity and low acoustic power, which is critical to protect cells from any thermal and mechanical damages, the technique may be used for transportation of cells in cell biology, biosensors, and tissue engineering.

  10. RYPOS Trap Field Demonstrations Part 1 | Department of Energy

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

    1 RYPOS Trap Field Demonstrations Part 1 2002 DEER Conference Presentation: RYPOS Inc. 2002_deer_depetrillo1.pdf (812.87 KB) More Documents & Publications RYPOS Trap Field Demonstrations Part 2

  11. RYPOS Trap Field Demonstrations Part 2 | Department of Energy

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

    2 RYPOS Trap Field Demonstrations Part 2 2002 DEER Conference Presentation: RYPOS Inc. 2002_deer_depetrillo2.pdf (1016 KB) More Documents & Publications RYPOS Trap Field Demonstrations Part 1

  12. Review of Orifice Plate Steam Traps | Department of Energy

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

    Review of Orifice Plate Steam Traps Review of Orifice Plate Steam Traps This guide was prepared to serve as a foundation for making informed decisions about when orifice plate...

  13. Trapping and Measuring Charged Particles in Liquids - Energy Innovation

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

    Portal Advanced Materials Advanced Materials Find More Like This Return to Search Trapping and Measuring Charged Particles in Liquids Oak Ridge National Laboratory Contact ORNL About This Technology Publications: PDF Document Publication Printable fact sheet (552 KB) Planar aqueous Paul trap (PAPT) devices and experimental platform Planar aqueous Paul trap (PAPT) devices and experimental platform Technology Marketing SummaryA nanoscale version of the Paul ion trap was developed by

  14. Inspect and Repair Steam Traps | Department of Energy

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

    Inspect and Repair Steam Traps Inspect and Repair Steam Traps This tip sheet on inspecting and repairing steam traps provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies. STEAM TIP SHEET #1 Inspect and Repair Steam Traps (January 2012) (393.77 KB) More Documents & Publications Flash High-Pressure Condensate to Regenerate Low-Pressure Steam Steam Pressure Reduction: Opportunities and Issues Use Steam Jet Ejectors or Thermocompressors

  15. High voltage gas insulated transmission line with continuous particle trapping

    DOE Patents [OSTI]

    Cookson, Alan H. (Pittsburgh, PA); Dale, Steinar J. (Monroeville, PA)

    1983-01-01

    This invention provides a novel high voltage gas insulated transmission line utilizing insulating supports spaced at intervals with snap-in means for supporting a continuous trapping apparatus and said trapping apparatus having perforations and cutouts to facilitate trapping of contaminating particles and system flexibility.

  16. Role of self-trapped holes in the photoconductive gain of β-gallium oxide Schottky diodes

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

    Armstrong, Andrew M.; Crawford, Mary H.; Jayawardena, Asanka; Ahyi, Ayayi; Dhar, Sarit

    2016-03-10

    Solar-blind photodetection and photoconductive gain > 50 corresponding to a responsivity > 8 A/W was observed for β-Ga2O3 Schottky photodiodes. We investigated the origin of photoconductive gain. Current-voltage characteristics of the diodes did not indicate avalanche breakdown, which excludes carrier multiplication by impact ionization as the source for gain. However, photocapacitance measurements indicated a mechanism for hole localization for above-band gap illumination, suggesting self-trapped hole formation. Comparison of photoconductivity and photocapacitance spectra indicated that self-trapped hole formation coincides with the strong photoconductive gain. We conclude that self-trapped hole formation near the Schottky diode lowers the effective Schottky barrier in reversemore » bias, producing photoconductive gain. Ascribing photoconductive gain to an inherent property like self-trapping of holes can explain the operation of a variety of β-Ga2O3 photodetectors.« less

  17. Current transient spectroscopy for trapping analysis on Au-free AlGaN/GaN Schottky barrier diode

    SciTech Connect (OSTI)

    Hu, J. Groeseneken, G.; Stoffels, S.; Lenci, S.; Venegas, R.; Decoutere, S.; Bakeroot, B.

    2015-02-23

    This paper presents a combined technique of high voltage off-state stress and current transient measurements to investigate the trapping/de-trapping characteristics of Au-free AlGaN/GaN Schottky barrier diodes. The device features a symmetric three-terminal structure with a central anode contact surrounded by two separate cathodes. Under the diode off-state stress conditions, the two separate cathodes were electrically shorted. The de-trapping dynamics was studied by monitoring the recovery of the two-dimensional electron gas (2DEG) current at different temperatures by applying 0.5?V at cathode 2 while grounding cathode 1. During the recovery, the anode contact acts as a sensor of changes in diode leakage current. This leakage variation was found to be mainly due to the barrier height variation. With this method, the energy level and capture cross section of different traps in the AlGaN/GaN Schottky barrier diode can be extracted. Furthermore, the physical location of different trapping phenomena is indicated by studying the variation of the diode leakage current during the recovery. We have identified two distinct trapping mechanisms: (i) electron trapping at the AlGaN surface in the vicinity of the Schottky contact which results in the leakage reduction (barrier height ?{sub B} increase) together with R{sub ON} degradation; (ii) the electron trapping in the GaN channel layer which partially depletes the 2DEG. The physical origin of the two different traps is discussed in the text.

  18. Analysis of electron dynamics in non-ideal Penning traps

    SciTech Connect (OSTI)

    Coppa, G.; Mulas, R.; D'Angola, A.

    2012-06-15

    Penning traps that are used for particular applications, such as in ion pump technology, Larmor, bouncing, and diocotron frequencies, can be of the same order of magnitude. The paper deals with the dynamics of electrons confined in such devices starting from the study of the properties of the trajectories. In cases of interest, in which electron-neutral collision frequency is much smaller with respect to the characteristic frequencies of the motion, suitable time averages of the trajectories are introduced in order to simplify the analysis of the problem. In the work, time averages have been calculated in a simple way by using an approximate r-z decoupling of the effective potential. Results obtained with the method are presented and discussed in both linear and nonlinear regimes.

  19. Non-vanishing ponderomotive AC electrophoretic effect for particle trapping

    SciTech Connect (OSTI)

    Guan, Weihau; Park, Jae Hyun nmn; Krstic, Predrag S; Reed, Mark A

    2011-01-01

    We present here a study on overlooked aspects of alternating current (AC) electrokinetics AC electrophoretic (ACEP) phenomena. The dynamics of a particle with both polarizability and net charges in a non-uniform AC electric trapping field is investigated. It is found that either electrophoretic (EP) or dielectrophoretic (DEP) effects can dominate the trapping dynamics, depending on experimental conditions. A dimensionless parameter gamma is developed to predict the relative strength of EP and DEP effects in a quadrupole AC field. An ACEP trap is feasible for charged particles in salt-free or low salt concentration solutions. In contrast to DEP traps, an ACEP trap favors the downscaling of the particle size.

  20. Project Closeout Report Francium trapping facility at Triumf

    SciTech Connect (OSTI)

    Orozco, Luis A

    2014-09-30

    This is a report of the construction of a Francium Trapping Facility (FTF) at the Isotope Separator and Accelerator (ISAC) of TRIUMF in Vancouver, Canada, where the Francium Parity Non Conservation (FrPNC) international collaboration has its home. This facility will be used to study fundamental symmetries with high-resolution atomic spectroscopy. The primary scientific objective of the program is a measurement of the anapole moment of francium in a chain of isotopes by observing the parity violation induced by the weak interaction. The anapole moment of francium and associated signal are expected to be ten times larger than in cesium, the only element in which an anapole moment has been observed. The measurement will provide crucial information for better understanding weak hadronic interactions in the context of Quantum Chromodynamics (QCD). The methodology combines nuclear and particle physics techniques for the production of francium with precision measurements based on laser cooling and trapping and microwave spectroscopy. The program builds on an initial series of atomic spectroscopy measurements of the nuclear structure of francium, based on isotope shifts and hyperfine anomalies, before conducting the anapole moment measurements, these measurements performed during commissioning runs help understand the atomic and nuclear structure of Fr.

  1. Milling time and temperature dependence on Fe{sub 2}TiO{sub 5} nanoparticles synthesized by mechanical alloying method

    SciTech Connect (OSTI)

    Fajarin, R. Purwaningsih, H. Widyastuti, Susanti, D. Helmy, R. Kurnia

    2014-09-25

    Fe{sub 2}TiO{sub 5} is one type of titanate oxides which has M{sub x}Ti{sub y}O{sub z} crystal structure. It has various kinds of applications due to its electric and magnetic properties such as spintronics, electromagnetic devices, and gas sensor. In this study, Fe{sub 2}TiO{sub 5} nanoparticles were synthesized by simple mechanical alloying using planetary ball milling machine with various milling times and sintering temperatures. TiO{sub 2} and Fe{sub 2}O{sub 3} powders obtained from coprecipitation process were used as starting materials. The resulted Fe{sub 2}TiO{sub 5} powders were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Vibration Sample Magnetometer (VSM) in order to observe crystal quality, particles morphology, and magnetic properties respectively. As the milling time increases and the sintering temperature decreases, the crystal size of Fe{sub 2}TiO{sub 5} phase decreases. The smallest crystal size of the synthesized Fe{sub 2}TiO{sub 5} nanoparticles was ∼ 51 nm obtained by the milling time of 25 hours and sintering at 1100°C. The distribution of the resulted Fe{sub 2}TiO{sub 5} nanoparticles was not so homogeneous due to the appearance of small amount impurities. The VSM measurements show that a paramagnetic property was observed which should be analyzed more details on the low external magnetic fields.

  2. Role of Trapping Impurities on He Desorption and Clustering in Irradiated a-Fe

    SciTech Connect (OSTI)

    Ortiz, Christophe J.; Caturla, Maria Jose; Fu, Chu Chun; Willaime, Francois

    2008-07-01

    It is well-known that impurities affect the migration of intrinsic point defects in metals. For instance, carbon is a common impurity in Fe that significantly retards diffusion of vacancies. Under fusion irradiation conditions, high levels of He are produced by transmutation reactions. This element strongly interacts with vacancies produced during irradiation and agglomerate into stable He-vacancy clusters that can deteriorate the mechanical properties of the material. A physically-based model accounting for the interactions between He, point defects (interstitials and vacancies) and trapping impurities is therefore necessary to understand and predict damage evolution in Fe. We have used a multi-scale approach to predict the evolution of He in the presence of impurities in irradiated Fe. Density Functional Theory (DFT) calculations were performed to investigate the migration mechanisms and to determine the activation energies of the different atomistic processes. The influence of impurities - such as carbon - on the binding energies of small He-vacancy clusters was also studied. Using the information obtained by DFT a physically-based model was developed and implemented in a kinetic Monte Carlo (kMC) code to follow the evolution of He in Fe. In addition, a model based on the rate theory (RT) was developed in order to achieve larger simulation times and volumes. Results obtained with this model, which is based on a mean field approximation are compared to those obtained with kMC. Using this multi-scale approach, the simulation results are used to interpret the different stages of thermal He desorption experiments and to determine the predominant migration mechanism. The influence of impurities which affect the diffusion of point defects or modify the binding energies of He-vacancy type clusters is also studied. (authors)

  3. Landau damping and the onset of particle trapping in quantum plasmas

    SciTech Connect (OSTI)

    Daligault, Jrme

    2014-04-15

    Using analytical theory and simulations, we assess the impact of quantum effects on non-linear wave-particle interactions in quantum plasmas. We more specifically focus on the resonant interaction between Langmuir waves and electrons, which, in classical plasmas, lead to particle trapping. Two regimes are identified depending on the difference between the time scale of oscillation t{sub B}(k)=?(m/eEk) of a trapped electron and the quantum time scale t{sub q}(k)=2m/?k{sup 2} related to recoil effect, where E and k are the wave amplitude and wave vector. In the classical-like regime, t{sub B}(k)?trapped in the wave troughs and greatly affect the evolution of the system long before the wave has had time to Landau damp by a large amount according to linear theory. In the quantum regime, t{sub B}(k)?>?t{sub q}(k), particle trapping is hampered by the finite recoil imparted to resonant electrons in their interactions with plasmons.

  4. Gas turbine engines with particle traps

    DOE Patents [OSTI]

    Boyd, Gary L.; Sumner, D. Warren; Sheoran, Yogendra; Judd, Z. Daniel

    1992-01-01

    A gas turbine engine (10) incorporates a particle trap (46) that forms an entrapment region (73) in a plenum (24) which extends from within the combustor (18) to the inlet (32) of a radial-inflow turbine (52, 54). The engine (10) is thereby adapted to entrap particles that originate downstream from the compressor (14) and are otherwise propelled by combustion gas (22) into the turbine (52, 54). Carbonaceous particles that are dislodged from the inner wall (50) of the combustor (18) are incinerated within the entrapment region (73) during operation of the engine (10).

  5. Isotopic abundance in atom trap trace analysis

    DOE Patents [OSTI]

    Lu, Zheng-Tian; Hu, Shiu-Ming; Jiang, Wei; Mueller, Peter

    2014-03-18

    A method and system for detecting ratios and amounts of isotopes of noble gases. The method and system is constructed to be able to measure noble gas isotopes in water and ice, which helps reveal the geological age of the samples and understand their movements. The method and system uses a combination of a cooled discharge source, a beam collimator, a beam slower and magneto-optic trap with a laser to apply resonance frequency energy to the noble gas to be quenched and detected.

  6. Sales lag sparks steam trap diversity

    SciTech Connect (OSTI)

    Crawford, E.

    1980-03-03

    Competing manufacturers have broadened their product range and customer services in an effort to survive a tightened market and the introduction of unconventional devices. Users and vendors agree that rising energy costs now give inspection and maintenance of steam traps top priority. New products on the market are described. Competition has led to some questionable advertising and legal action. Fixed orifice and temperature-actuated valves are among the alternative products offered. Models of the major manufacturers are compared by type, pressure and condensate load range, primary use, and price.

  7. Trapping and aerogelation of nanoparticles in negative gravity hydrocarbon flames

    SciTech Connect (OSTI)

    Chakrabarty, Rajan K.; Novosselov, Igor V.; Beres, Nicholas D.; Moosmller, Hans; Sorensen, Christopher M.; Stipe, Christopher B.

    2014-06-16

    We report the experimental realization of continuous carbon aerogel production using a flame aerosol reactor by operating it in negative gravity (?g; up-side-down configuration). Buoyancy opposes the fuel and air flow forces in ?g, which eliminates convectional outflow of nanoparticles from the flame and traps them in a distinctive non-tipping, flicker-free, cylindrical flame body, where they grow to millimeter-size aerogel particles and gravitationally fall out. Computational fluid dynamics simulations show that a closed-loop recirculation zone is set up in ?g flames, which reduces the time to gel for nanoparticles by ?10{sup 6}?s, compared to positive gravity (upward rising) flames. Our results open up new possibilities of one-step gas-phase synthesis of a wide variety of aerogels on an industrial scale.

  8. Mesoscopic supersolid of dipoles in a trap

    SciTech Connect (OSTI)

    Golomedov, A. E.; Astrakharchik, G. E.; Lozovik, Yu. E.

    2011-09-15

    A mesoscopic system of dipolar bosons trapped by a harmonic potential is considered. The system has a number of physical realizations including dipole excitons, atoms with large dipolar moment, polar molecules, and Rydberg atoms in inhomogeneous electric field. We carry out a diffusion Monte Carlo simulation to define the quantum properties of a two-dimensional system of trapped dipoles at zero temperature. In dimensionless units the system is described by two control parameters, namely, the number of particles and the strength of the interparticle interaction. We have shown that when the interparticle interaction is strong enough a mesoscopic crystal is formed. As the strength of interactions is decreased a multistage melting takes place. Off-diagonal order in the system is tested using natural-orbitals analysis. We have found that the system might be Bose condensed even in the case of strong interparticle interactions. There is a set of parameters for which a spatially ordered structure is formed while simultaneously the fraction of Bose-condensed particles is nonzero. This might be considered as a realization of a mesoscopic supersolid.

  9. Gas insulated transmission line having tapered particle trapping ring

    DOE Patents [OSTI]

    Cookson, Alan H.

    1982-01-01

    A gas-insulated transmission line includes an outer sheath, an inner conductor, insulating supports and an insulating gas. A particle-trapping ring is secured to each insulating support, and it is comprised of a central portion and two tapered end portions. The ends of the particle trapping ring have a smaller diameter than the central portion of the ring, so as to enable the use of the particle trapping ring in a curved transmission line.

  10. Thermostatic/orifice trap reduces fuel, repair costs

    SciTech Connect (OSTI)

    Not Available

    1982-11-01

    This article is an evaluation of a steam trap that combines the continuous drain oriface with a thermostatically controlled trap oriface to efficiently remove condensate from virtually any steam system within its operating limits. This trap effectively reduces fuel and repair costs and has a capacity of 6000 il/hr, handles various pressures up to 600 psig, and operates against back pressures up to 90% of inlet pressure.

  11. Trapping in GaN-based metal-insulator-semiconductor transistors: Role of high drain bias and hot electrons

    SciTech Connect (OSTI)

    Meneghini, M. Bisi, D.; Meneghesso, G.; Zanoni, E.

    2014-04-07

    This paper describes an extensive analysis of the role of off-state and semi-on state bias in inducing the trapping in GaN-based power High Electron Mobility Transistors. The study is based on combined pulsed characterization and on-resistance transient measurements. We demonstrate thatby changing the quiescent bias point from the off-state to the semi-on stateit is possible to separately analyze two relevant trapping mechanisms: (i) the trapping of electrons in the gate-drain access region, activated by the exposure to high drain bias in the off-state; (ii) the trapping of hot-electrons within the AlGaN barrier or the gate insulator, which occurs when the devices are operated in the semi-on state. The dependence of these two mechanisms on the bias conditions and on temperature, and the properties (activation energy and cross section) of the related traps are described in the text.

  12. Wolf Trap, Virginia: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Bureau 2005 Place to 2006 CBSA Retrieved from "http:en.openei.orgwindex.php?titleWolfTrap,Virginia&oldid253815" Feedback Contact needs updating Image needs updating...

  13. Light Trapping, Absorption and Solar Energy Harvesting by Artificial...

    Office of Scientific and Technical Information (OSTI)

    Energy Harvesting by Artificial Materials Citation Details In-Document Search Title: Light Trapping, Absorption and Solar Energy Harvesting by Artificial Materials We provide ...

  14. Ball-grid array architecture for microfabricated ion traps (Journal...

    Office of Scientific and Technical Information (OSTI)

    Ball-grid array architecture for microfabricated ion traps Citation Details In-Document ... Country of Publication: United States Language: English Subject: 71 CLASSICAL AND QUANTUM ...

  15. On the Equivalence of Trapped Colloids, Pinned Vortices, and...

    Office of Scientific and Technical Information (OSTI)

    Title: On the Equivalence of Trapped Colloids, Pinned Vortices, and Spin Ice We investigate the recently reported analogies between pinned vortices in nano-structured ...

  16. Lean NOx Trap Regeneration Selectivity Towards N2O -- Similarities...

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

    Lean NOx Trap Regeneration Selectivity Towards N2O -- Similarities and Differences Between ... More Documents & Publications Spatiotemporal Distribution of NOx Storage: a Factor ...

  17. A Sub-Millimeter Solenoid Device for Trapping Paramagnetic Microbeads...

    Office of Scientific and Technical Information (OSTI)

    a paramagnetic microsphere trapping and separation device consisting of a copper solenoid ... to the design of magnetic-based separation devices because the ...

  18. Particle trapping: A key requisite of structure formation and...

    Office of Scientific and Technical Information (OSTI)

    Particle trapping is shown to control the existence of ... Journal Volume: 22; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International ...

  19. Biogas Purifications for Fuel Cells: SulfaTrap Sorbents

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

    Biogas Purifications for Fuel Cells SulfaTrap TM Sorbents Gökhan Alptekin, PhD Vice President, Technology Tel: 303 940 2349 galptekin@tda.com DOE Workshop on Gas Clean-up for Fuel Cell Applications Argonne National Laboratory March 7, 2014 TDA Research Inc. * Wheat Ridge, CO 80033 * www.tda.com Background - SulfaTrap TM Sorbents Bio-ethanol desulfurizer SulfaTrap TM sorbents for stationary/mobile fuel cell applications * Fundamental work started at TDA Research in 2002 * SulfaTrap LLC was

  20. Lean NOx Traps - Microstructural Studies of Real World and Model...

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

    KB) More Documents & Publications Low Temperature Emission Control Pre-Competitive Catalysis Research: Fundamental SulfationDesulfation Studies of Lean NOx Traps Investigation ...

  1. H2-Assisted NOx Traps: Test Cell Results Vehicle Installations...

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

    H2-Assisted NOx Traps: Test Cell Results Vehicle Installations 2003 DEER Conference Presentation: ArvinMeritor 2003deercrane.pdf (630.37 KB) More Documents & Publications ...

  2. Stable metal-organic frameworks containing single-molecule traps...

    Office of Scientific and Technical Information (OSTI)

    Title: Stable metal-organic frameworks containing single-molecule traps for enzyme encapsulation Authors: Feng, Dawei ; Liu, Tian-Fu ; Su, Jie ; Bosch, Mathieu ; Wei, Zhangwen ; ...

  3. Penning trap mass measurements on nobelium isotopes

    SciTech Connect (OSTI)

    Dworschak, M.; Block, M.; Ackermann, D.; Herfurth, F.; Hessberger, F. P.; Hofmann, S.; Vorobyev, G. K.; Audi, G.; Blaum, K.; Droese, C.; Marx, G.; Schweikhard, L.; Eliseev, S.; Ketter, J.; Fleckenstein, T.; Haettner, E.; Plass, W. R.; Scheidenberger, C.; Ketelaer, J.; Kluge, H.-J.

    2010-06-15

    The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt allows accurate mass measurements of radionuclides, produced in fusion-evaporation reactions and separated by the velocity filter SHIP from the primary beam. Recently, the masses of the three nobelium isotopes {sup 252-254}No were determined. These are the first direct mass measurements of transuranium elements, which provide new anchor points in this region. The heavy nuclides were produced in cold-fusion reactions by irradiating a PbS target with a {sup 48}Ca beam, resulting in production rates of the nuclei of interest of about one atom per second. In combination with data from decay spectroscopy our results are used to perform a new atomic-mass evaluation in this region.

  4. Contaminant trap for gas-insulated apparatus

    DOE Patents [OSTI]

    Adcock, James L.; Pace, Marshall O.; Christophorou, Loucas G.

    1984-01-01

    A contaminant trap for a gas-insulated electrical conductor is provided. A resinous dielectric body such as Kel-F wax, grease or other sticky polymeric or oligomeric compound is disposed on the inside wall of the outer housing for the conductor. The resinous body is sufficiently sticky at ambient temperatures to immobilize contaminant particles in the insulating gas on the exposed surfaces thereof. An electric resistance heating element is disposed in the resinous body to selectively raise the temperature of the resinous body to a molten state so that the contaminant particles collected on the surface of the body sink into the body so that the surface of the resinous body is renewed to a particle-less condition and, when cooled, returns to a sticky collecting surface.

  5. Debris trap in a turbine cooling system

    DOE Patents [OSTI]

    Wilson, Ian David

    2002-01-01

    In a turbine having a rotor and a plurality of stages, each stage comprising a row of buckets mounted on the rotor for rotation therewith; and wherein the buckets of at least one of the stages are cooled by steam, the improvement comprising at least one axially extending cooling steam supply conduit communicating with an at least partially annular steam supply manifold; one or more axially extending cooling steam feed tubes connected to the manifold at a location radially outwardly of the cooling steam supply conduit, the feed tubes arranged to supply cooling steam to the buckets of at least one of the plurality of stages; the manifold extending radially beyond the feed tubes to thereby create a debris trap region for collecting debris under centrifugal loading caused by rotation of the rotor.

  6. TIMING APPARATUS

    DOE Patents [OSTI]

    Bennett, A.E.; Geisow, J.C.H.

    1956-04-17

    The timing device comprises an escapement wheel and pallet, a spring drive to rotate the escapement wheel to a zero position, means to wind the pretensioned spring proportional to the desired signal time, and a cam mechanism to control an electrical signal switch by energizing the switch when the spring has been wound to the desired position, and deenergizing it when it reaches the zero position. This device produces an accurately timed signal variably witain the control of the operator.

  7. Centrality measures highlight proton traps and access points to proton highways in kinetic Monte Carlo trajectories

    SciTech Connect (OSTI)

    Krueger, Rachel A.; Haibach, Frederick G.; Fry, Dana L.; Gomez, Maria A.

    2015-04-21

    A centrality measure based on the time of first returns rather than the number of steps is developed and applied to finding proton traps and access points to proton highways in the doped perovskite oxides: AZr{sub 0.875}D{sub 0.125}O{sub 3}, where A is Ba or Sr and the dopant D is Y or Al. The high centrality region near the dopant is wider in the SrZrO{sub 3} systems than the BaZrO{sub 3} systems. In the aluminum-doped systems, a region of intermediate centrality (secondary region) is found in a plane away from the dopant. Kinetic Monte Carlo (kMC) trajectories show that this secondary region is an entry to fast conduction planes in the aluminum-doped systems in contrast to the highest centrality area near the dopant trap. The yttrium-doped systems do not show this secondary region because the fast conduction routes are in the same plane as the dopant and hence already in the high centrality trapped area. This centrality measure complements kMC by highlighting key areas in trajectories. The limiting activation barriers found via kMC are in very good agreement with experiments and related to the barriers to escape dopant traps.

  8. Charge Trapping in High Efficiency Alternating Copolymers: Implications in

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

    Organic Photovoltaic Device Efficiency | ANSER Center | Argonne-Northwestern National Laboratory Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency Home > Research > ANSER Research Highlights > Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency

  9. Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil

    SciTech Connect (OSTI)

    DeAngelis, Kristen; Allgaier, Martin; Chavarria, Yaucin; Fortney, Julian; Hugenholtz, Phillip; Simmons, Blake; Sublette, Kerry; Silver, Whendee; Hazen, Terry

    2011-07-14

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  10. Characterization of trapped lignin-degrading microbes in tropical forest soil

    SciTech Connect (OSTI)

    DeAngelis, K.M.; Allgaier, M.; Chavarria, Y.; Fortney, J.L.; Hugenholz, P.; Simmons, B.; Sublette, K.; Silver, W.L.; Hazen, T.C.

    2011-03-01

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  11. Ionization-Induced Electron Trapping inUltrarelativistic Plasma Wakes

    SciTech Connect (OSTI)

    Oz, E.; Deng, S.; Katsouleas, T.; Muggli, P.; Barnes, C.D.; Blumenfeld, I.; Decker, F.J.; Emma, P.; Hogan, M.J.; Ischebeck, R.; Iverson, R.H.; Kirby, N.; Krejcik, P.; O'Connell, C.; Siemann, R.H.; Walz, D.; Auerbach, D.; Clayton, C.E.; Huang, C.; Johnson, D.K.; Joshi, C.; /UCLA

    2007-04-06

    The onset of trapping of electrons born inside a highly relativistic, 3D beam-driven plasma wake is investigated. Trapping occurs in the transition regions of a Li plasma confined by He gas. Li plasma electrons support the wake, and higher ionization potential He atoms are ionized as the beam is focused by Li ions and can be trapped. As the wake amplitude is increased, the onset of trapping is observed. Some electrons gain up to 7.6 GeV in a 30.5 cm plasma. The experimentally inferred trapping threshold is at a wake amplitude of 36 GV/m, in good agreement with an analytical model and PIC simulations.

  12. Electrostatic particle trap for ion beam sputter deposition

    DOE Patents [OSTI]

    Vernon, Stephen P.; Burkhart, Scott C.

    2002-01-01

    A method and apparatus for the interception and trapping of or reflection of charged particulate matter generated in ion beam sputter deposition. The apparatus involves an electrostatic particle trap which generates electrostatic fields in the vicinity of the substrate on which target material is being deposited. The electrostatic particle trap consists of an array of electrode surfaces, each maintained at an electrostatic potential, and with their surfaces parallel or perpendicular to the surface of the substrate. The method involves interception and trapping of or reflection of charged particles achieved by generating electrostatic fields in the vicinity of the substrate, and configuring the fields to force the charged particulate material away from the substrate. The electrostatic charged particle trap enables prevention of charged particles from being deposited on the substrate thereby enabling the deposition of extremely low defect density films, such as required for reflective masks of an extreme ultraviolet lithography (EUVL) system.

  13. Optical trapping apparatus, methods and applications using photonic crystal resonators

    DOE Patents [OSTI]

    Erickson, David; Chen, Yih-Fan

    2015-06-16

    A plurality of photonic crystal resonator optical trapping apparatuses and a plurality optical trapping methods using the plurality of photonic crystal resonator optical trapping apparatuses include located and formed over a substrate a photonic waveguide that is coupled (i.e., either separately coupled or integrally coupled) with a photonic crystal resonator. In a particular embodiment, the photonic waveguide and the photonic crystal resonator comprise a monocrystalline silicon (or other) photonic material absent any chemical functionalization. In another particular embodiment, the photonic waveguide and the photonic crystal resonator comprise a silicon nitride material which when actuating the photonic crystal resonator optical trapping apparatus with a 1064 nanometer resonant photonic radiation wavelength (or other resonant photonic radiation wavelength in a range from about 700 to about 1200 nanometers) provides no appreciable heating of an aqueous sample fluid that is analyzed by the photonic crystal resonator optical trapping apparatus.

  14. A Pneumatic Actuated Microfluidic Beads-Trapping Device

    SciTech Connect (OSTI)

    Shao, Guocheng; Cai, Ziliang; Wang, Jun; Wang, Wanjun; Lin, Yuehe

    2011-08-20

    The development of a polydimethylsiloxane (PDMS) microfluidic microbeads trapping device is reported in this paper. Besides fluid channels, the proposed device includes a pneumatic control chamber and a beads-trapping chamber with a filter array structure. The pneumatic flow control chamber and the beads-trapping chamber are vertically stacked and separated by a thin membrane. By adjusting the pressure in the pneumatic control chamber, the membrane can either be pushed against the filter array to set the device in trapping mode or be released to set the device in releasing mode. In this paper, a computational fluid dynamics simulation was conducted to optimize the geometry design of the filter array structure; the device fabrication was also carried out. The prototype device was tested and the preliminary experimental results showed that it can be used as a beads-trapping unit for various biochemistry and analytical chemistry applications, especially for flow injection analysis systems.

  15. Storage of Ultracold Neutrons in the Magneto-Gravitational Trap of the UCN Experiment

    SciTech Connect (OSTI)

    Salvat, D. J.; Adamek, E. R.; Barlow, D.; Bowman, James D; Broussard, L. J.; Callahan, N. B.; Clayton, S. M.; Cude-Woods, C.; Currie, S.; Dees, E. B.; Fox, W.; Geltenbort, P.; Hickerson, K. P.; Holley, A. T.; Liu, C.-Y.; Makela, M.; Medina, J.; Morley, D. J.; Morris, C. L.; Penttila, Seppo I; Ramsey, J.; Saunders, A.; Seestrom, S. J.; Sharapov, E. I.; Sjue, S. K. L.; Slaughter, B. A.; Vanderwerp, J.; VornDick, B.; Walstrom, P. L.; Wang, Z.; Womack, T. L.; Young, A. R.

    2014-01-01

    The UCN experiment is designed to measure the lifetime n of the free neutron by trapping ultracold neutrons (UCN) in a magneto-gravitational trap. An asymmetric bowl-shaped NdFeB magnet Halbach array confines low-field-seeking UCN within the apparatus, and a set of electromagnetic coils in a toroidal geometry provides a background holding field to eliminate depolarization-induced UCN loss caused by magnetic field nodes. We present a measurement of the storage time store of the trap by storing UCN for various times and counting the survivors. The data are consistent with a single exponential decay, and we find store = 860 19 s, within 1 of current global averages for n. The storage time with the holding field deactivated is found to be store = 470 160 s; this decreased storage time is due to the loss of UCN, which undergo Majorana spin flips while being stored. We discuss plans to increase the statistical sensitivity of the measurement and investigate potential systematic effects.

  16. Two-dimensional Vlasov simulation of electron plasma wave trapping, wavefront bowing, self-focusing, and sideloss

    SciTech Connect (OSTI)

    Banks, J. W.; Berger, R. L.; Cohen, B. I.; Hittinger, J. A. F.; Brunner, S.

    2011-05-15

    Two-dimensional Vlasov simulations of nonlinear electron plasma waves are presented, in which the interplay of linear and nonlinear kinetic effects is evident. The plasma wave is created with an external traveling wave potential with a transverse envelope of width {Delta}y such that thermal electrons transit the wave in a ''sideloss'' time, t{sub sl{approx}{Delta}}y/v{sub e}. Here, v{sub e} is the electron thermal velocity. The quasisteady distribution of trapped electrons and its self-consistent plasma wave are studied after the external field is turned off. In cases of particular interest, the bounce frequency, {omega}{sub be}=k{radical}(e{phi}/m{sub e}), satisfies the trapping condition {omega}{sub be}t{sub sl}>2{pi} such that the wave frequency is nonlinearly downshifted by an amount proportional to the number of trapped electrons. Here, k is the wavenumber of the plasma wave and {phi} is its electric potential. For sufficiently short times, the magnitude of the negative frequency shift is a local function of {phi}. Because the trapping frequency shift is negative, the phase of the wave on axis lags the off-axis phase if the trapping nonlinearity dominates linear wave diffraction. In this case, the phasefronts are curved in a focusing sense. In the opposite limit, the phasefronts are curved in a defocusing sense. Analysis and simulations in which the wave amplitude and transverse width are varied establish criteria for the development of each type of wavefront. The damping and trapped-electron-induced focusing of the finite-amplitude electron plasma wave are also simulated. The damping rate of the field energy of the wave is found to be about the sideloss rate, {nu}{sub e{approx}}t{sub sl}{sup -1}. For large wave amplitudes or widths {Delta}y, a trapping-induced self-focusing of the wave is demonstrated.

  17. A Landau fluid model for dissipative trapped electron modes

    SciTech Connect (OSTI)

    Hedrick, C.L.; Leboeuf, J.N.; Sidikman, K.L.

    1995-09-01

    A Landau fluid model for dissipative trapped electron modes is developed which focuses on an improved description of the ion dynamics. The model is simple enough to allow nonlinear calculations with many harmonics for the times necessary to reach saturation. The model is motivated by a discussion that starts with the gyro-kinetic equation and emphasizes the importance of simultaneously including particular features of magnetic drift resonance, shear, and Landau effects. To ensure that these features are simultaneously incorporated in a Landau fluid model with only two evolution equations, a new approach to determining the closure coefficients is employed. The effect of this technique is to reduce the matching of fluid and kinetic responses to a single variable, rather than two, and to allow focusing on essential features of the fluctuations in question, rather than features that are only important for other types of fluctuations. Radially resolved nonlinear calculations of this model, advanced in time to reach saturation, are presented to partially illustrate its intended use. These calculations have a large number of poloidal and toroidal harmonics to represent the nonlinear dynamics in a converged steady state which includes cascading of energy to both short and long wavelengths.

  18. Small-angle neutron scattering measurement of deuterium trapping at dislocations and grain boundaries in palladium

    SciTech Connect (OSTI)

    Heuser, B.J.

    1991-01-01

    Small angle neutron scattering measurements have been performed on deformed single and polycrystalline palladium with and without deuterium dissolved in the solution phase at room temperature. The purpose of these experiments was to directly measure the spatial distribution of trapped deuterium at dislocations in the deformed metal. The net scattering cross section for the same smaple with and without deuterium shows a behavior expected from deuterium correlation with dislocations froming rod-like scattering structures. The measured cross sections indicate the trapped deuterium is within 2 to 3 Burgers vectors of the dislocation core. On average 1 to 3 deuterons per {angstrom} are trapped at the dislocations in the deformed samples. The measurements also indicate the straight, rod-like correlation geometry extends on average 50 to 100 {angstrom} along the dislocations. Dislocation densities on the order of 5 {times} 10{sup 11} cm/cm{sup 3} were found for all samples investigated. Net scattering from a well annealed polycrystalline palladium sample exhibiting a behavior expected from spherical shells has been observed. This net scattering is attributed to deuterium trapping at grain boundaries in the polycrystalline sample. net scattering in excess of that expected from deuterium correlated at dislocations was also observed in a deformed polycrystalline measurement. This too is attributed to deuterium trapping at grain boundaries. The dislocation substructure of the deformed palladium samples was characterized by transmission electron microscopy (TEM). This analysis illustrated the cellular arrangement that evolved in palladium during cold working. The presence of MnO particles also was confirmed by TEM analysis.

  19. An Energy Signature Scheme for Steam Trap Assessment and Flow Rate Estimation Using Pipe-Induced Acoustic Measurements

    SciTech Connect (OSTI)

    Olama, Mohammed M; Allgood, Glenn O; Kuruganti, Phani Teja; Lake, Joe E

    2012-01-01

    The US Congress has passed legislation dictating that all government agencies establish a plan and process for improving energy efficiencies at their sites. In response to this legislation, Oak Ridge National Laboratory (ORNL) has recently conducted a pilot study to explore the deployment of a wireless sensor system for a real-time measurement-based energy efficiency optimization framework within the steam distribution system within the ORNL campus. We make assessments on the real-time status of the distribution system by observing the state measurements of acoustic sensors mounted on the steam pipes/traps/valves. In this paper, we describe a spectral-based energy signature scheme that interprets acoustic vibration sensor data to estimate steam flow rates and assess steam traps health status. Experimental results show that the energy signature scheme has the potential to identify different steam trap health status and it has sufficient sensitivity to estimate steam flow rate. Moreover, results indicate a nearly quadratic relationship over the test region between the overall energy signature factor and flow rate in the pipe. The analysis based on estimated steam flow and steam trap status helps generate alerts that enable operators and maintenance personnel to take remedial action. The goal is to achieve significant energy-saving in steam lines by monitoring and acting on leaking steam pipes/traps/valves.

  20. Cast-to-shape electrokinetic trapping medium

    DOE Patents [OSTI]

    Shepodd, Timothy J.; Franklin, Elizabeth; Prickett, Zane T.; Artau, Alexander

    2004-08-03

    A three-dimensional microporous polymer network material, or monolith, cast-to-shape in a microchannel. The polymer monolith, produced by a phase separation process, is capable of trapping and retaining charged protein species from a mixture of charged and uncharged species under the influence of an applied electric field. The retained charged protein species are released from the porous polymer monolith by a pressure driven flow in the substantial absence of the electric field. The pressure driven flow is independent of direction and thus neither means to reverse fluid flow nor a multi-directional flow field is required, a single flow through the porous polymer monolith can be employed, in contrast to prior art systems. The monolithic polymer material produced by the invention can function as a chromatographic medium. Moreover, by virtue of its ability to retain charged protein species and quantitatively release the retained species the porous polymer monolith can serve as a means for concentrating charged protein species from, for example, a dilute solution.

  1. Cast-to-shape electrokinetic trapping medium

    DOE Patents [OSTI]

    Shepodd, Timothy J.; Franklin, Elizabeth; Prickett, Zane T.; Artau, Alexander

    2006-05-30

    A three-dimensional microporous polymer network material, or monolith, cast-to-shape in a microchannel. The polymer monolith, produced by a phase separation process, is capable of trapping and retaining charged protein species from a mixture of charged and uncharged species under the influence of an applied electric field. The retained charged protein species are released from the porous polymer monolith by a pressure driven flow in the substantial absence of the electric field. The pressure driven flow is independent of direction and thus neither means to reverse fluid flow nor a multi-directional flow field is required, a single flow through the porous polymer monolith can be employed, in contrast to prior art systems. The monolithic polymer material produced by the invention can function as a chromatographic medium. Moreover, by virtue of its ability to retain charged protein species and quantitatively release the retained species the porous polymer monolith can serve as a means for concentrating charged protein species from, for example, a dilute solution.

  2. Using malaise traps to sample ground beetles (Coleoptera. Carabidae)

    SciTech Connect (OSTI)

    Ulyshen, Michael D.; Hanula, James L.; Horn, Scott

    2012-04-02

    Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and trap-shy species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.

  3. Using malaise traps to sample ground beetles (Coleoptera: Carabidae).

    SciTech Connect (OSTI)

    Ulyshen, Michael D., James L. Hanula, and Scott Horn

    2005-01-01

    Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and ? ????trap-shy?¢??? species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.

  4. Charge transfer mechanism in titanium-doped microporous silica for photocatalytic water-splitting applications

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

    Sapp, Wendi; Koodali, Ranjit; Kilin, Dmitri

    2016-02-29

    Solar energy conversion into chemical form is possible using artificial means. One example of a highly-efficient fuel is solar energy used to split water into oxygen and hydrogen. Efficient photocatalytic water-splitting remains an open challenge for researchers across the globe. Despite significant progress, several aspects of the reaction, including the charge transfer mechanism, are not fully clear. Density functional theory combined with density matrix equations of motion were used to identify and characterize the charge transfer mechanism involved in the dissociation of water. A simulated porous silica substrate, using periodic boundary conditions, with Ti4+ ions embedded on the inner poremore » wall was found to contain electron and hole trap states that could facilitate a chemical reaction. A trap state was located within the silica substrate that lengthened relaxation time, which may favor a chemical reaction. A chemical reaction would have to occur within the window of photoexcitation; therefore, the existence of a trapping state may encourage a chemical reaction. Furthermore, this provides evidence that the silica substrate plays an integral part in the electron/hole dynamics of the system, leading to the conclusion that both components (photoactive materials and support) of heterogeneous catalytic systems are important in optimization of catalytic efficiency.« less

  5. Power-Amplified Predatory Strikes in Trap-Jaw Spiders

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

    Power-Amplified Predatory Strikes in Trap-Jaw Spiders Power-Amplified Predatory Strikes in Trap-Jaw Spiders Print Friday, 10 June 2016 13:23 "Trap-jaw" spiders are tiny (about 2 mm), ground-dwelling spiders that rely on hunting rather than web-building to capture prey. Hannah Wood, curator of spiders at the Smithsonian's National Museum of Natural History, was curious as to why these spiders' carapaces (their front sections) seemed almost neck-like and their chelicerae (mandibles or

  6. Movement of particles using sequentially activated dielectrophoretic particle trapping

    DOE Patents [OSTI]

    Miles, Robin R.

    2004-02-03

    Manipulation of DNA and cells/spores using dielectrophoretic (DEP) forces to perform sample preparation protocols for polymerized chain reaction (PCR) based assays for various applications. This is accomplished by movement of particles using sequentially activated dielectrophoretic particle trapping. DEP forces induce a dipole in particles, and these particles can be trapped in non-uniform fields. The particles can be trapped in the high field strength region of one set of electrodes. By switching off this field and switching on an adjacent electrodes, particles can be moved down a channel with little or no flow.

  7. Modeling the Regeneration Chemistry of Lean NOx Traps | Department of

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

    Energy the Regeneration Chemistry of Lean NOx Traps Modeling the Regeneration Chemistry of Lean NOx Traps Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs. 2006_deer_larson.pdf (637.26 KB) More Documents & Publications Kinetic and Performance Studies of the Regeneration Phase of Model Pt/Rh/Ba NOx Traps for Design and Optimization Production, Storage, and FC Analysis

  8. Trap seal for open circuit liquid cooled turbines

    DOE Patents [OSTI]

    Grondahl, Clayton M.; Germain, Malcolm R.

    1980-01-01

    An improved trap seal for open circuit liquid cooled turbines is disclosed. The trap seal of the present invention includes an annular recess formed in the supply conduit of cooling channels formed in the airfoil of the turbine buckets. A cylindrical insert is located in the annular recesses and has a plurality of axial grooves formed along the outer periphery thereof and a central recess formed in one end thereof. The axial grooves and central recess formed in the cylindrical insert cooperate with the annular recess to define a plurality of S-shaped trap seals which permit the passage of liquid coolant but prohibit passage of gaseous coolant.

  9. Synergies of High-Efficiency Clean Combustion and Lean NOx Trap...

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

    Synergies of High-Efficiency Clean Combustion and Lean NOx Trap Catalysts Synergies of High-Efficiency Clean Combustion and Lean NOx Trap Catalysts investigation of potential ...

  10. Nitrogen Oxides as a Chemistry Trap in Detonating Oxygen-Rich...

    Office of Scientific and Technical Information (OSTI)

    Conference: Nitrogen Oxides as a Chemistry Trap in Detonating Oxygen-Rich Materials Citation Details In-Document Search Title: Nitrogen Oxides as a Chemistry Trap in Detonating ...

  11. Real-Time Particulate Mass Measurements Pre and Post Diesel Particulat...

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

    More Documents & Publications Advanced Radio Frequency-Based Sensors for Monitoring Diesel Particulate Filter Loading and Regeneration Real-Time Measurement of Diesel Trap ...

  12. Experimental investigation of plasma flows in open trap with toroidal diverter under ECR discharge

    SciTech Connect (OSTI)

    Berezkin, A. V. Bragin, E. Yu. Zhil’tsov, V. A. Kulygin, V. M. Yanchenkov, S. V.

    2015-12-15

    The results of experimental investigations of plasma flows from an open trap with a toroidal diverter are presented. Cold plasma is generated when introducing microwave power under conditions of electron cyclotron resonance (ECR). The radiation is introduced by a waveguide through a vacuum-tight ceramic window across the axis of the device. By means of the Langmuir probes, the spatial distributions of plasma parameters are measured. The highest density is limited to a critical value n{sub c} (∼10{sup 12} cm{sup –3}) for the generator frequency under use. It is found that the temperature and density of the plasma in the trap and in escaping flows are almost independent of the radius when the ECR zone is located near the open-trap confinement region and the density is close to n{sub c}. At the density n < n{sub c}, ring plasma structures, which collapse under the action of a low-frequency instability, are observed near the separatrix. The possible mechanisms of the occurrence of plasma structures and the nature of the plasma streams are discussed.

  13. Characterization of trapped gas saturation and heterogeneity in core samples using miscible-displacement experiments

    SciTech Connect (OSTI)

    Smith, D.H.; Jikich, S.A.

    1994-12-31

    Trapped gas saturation and permeability heterogeneity were evaluated in Berea cores at reservoir conditions, using standard miscible displacement experiments, with and without surfactants. Pressure and production history were influenced by core heterogeneity and foam lamellae formation when aqueous surfactant was present in the core. A simple dispersion model and a three-coefficient dispersion-capacitance model (Coates-Smith) were fit to the experimental data. The dispersion-capacitance model successfully matched the experiments in which foam lamella formed, while the simple dispersion model was used only for determining initial core flow heterogeneity. The objective of the dispersion-capacitance model was to estimate trapped gas saturations; however longitudinal dispersion and mass transfer also were examined. The results show that the dispersion-capacitance model accurately fits trapped gas saturation controlled by rock heterogeneities and foam lamellae for lamella generating mechanisms that allow a continuous gas phase (leave-behind lamellae). The practical applications resulting from this study can aid in core sample selection and scaling short laboratory corefloods to field dimensions for applications to foam stimulation and underground storage of natural gas.

  14. Cooling the motion of diamond nanocrystals in a magneto-gravitational trap in high vacuum

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

    Hsu, Jen -Feng; Ji, Peng; Lewandowski, Charles W.; D’Urso, Brian

    2016-07-22

    Levitated diamond nanocrystals with nitrogen-vacancy (NV) centres in high vacuum have been proposed as a unique system for experiments in fundamental quantum mechanics, including the generation of large quantum superposition states and tests of quantum gravity. This system promises extreme isolation from its environment while providing quantum control and sensing through the NV centre spin. While optical trapping has been the most explored method of levitation, recent results indicate that excessive optical heating of the nanodiamonds under vacuum may make the method impractical with currently available materials. Here, we study an alternative magneto-gravitational trap for diamagnetic particles, such as diamondmore » nanocrystals, with stable levitation from atmospheric pressure to high vacuum. Magnetic field gradients from permanent magnets confine the particle in two dimensions, while confinement in the third dimension is gravitational. Furthermore, we demonstrate that feedback cooling of the centre-of-mass motion of a trapped nanodiamond cluster results in cooling of one degree of freedom to less than 1 K.« less

  15. Near-field acoustic microbead trapping as remote anchor for single particle manipulation

    SciTech Connect (OSTI)

    Hwang, Jae Youn; Cheon, Dong Young; Shin, Hyunjune; Kim, Hyun Bin; Lee, Jungwoo

    2015-05-04

    We recently proposed an analytical model of a two-dimensional acoustic trapping of polystyrene beads in the ray acoustics regime, where a bead diameter is larger than the wavelength used. As its experimental validation, this paper demonstrates the transverse (or lateral) trapping of individual polystyrene beads in the near field of focused ultrasound. A 100 μm bead is immobilized on the central beam axis by a focused sound beam from a 30 MHz single element lithium niobate transducer, after being laterally displaced through hundreds of micrometers. Maximum displacement, a longest lateral distance at which a trapped bead can be directed towards the central axis, is thus measured over a discrete frequency range from 24 MHz to 36 MHz. The displacement data are found to be between 323.7 μm and 470.2 μm, depending on the transducer's driving frequency and input voltage amplitude. The experimental results are compared with their corresponding model values, and their relative errors lie between 0.9% and 3.9%. The results suggest that this remote maneuvering technique may be employed to manipulate individual cells through solid microbeads, provoking certain cellular reactions to localized mechanical disturbance without direct contact.

  16. Stable Metal-Organic Frameworks Containing Single-Molecule Traps...

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

    Stable Metal-Organic Frameworks Containing Single-Molecule Traps for Enzyme Encapsulation Previous Next List Dawei Feng, Tian-Fu Liu, Jie Su, Mathieu Bosch, Zhangwen Wei, Wei Wan,...

  17. Catch and Release: Reaction Dynamics from a Freed "Tension Trapped...

    Office of Scientific and Technical Information (OSTI)

    Title: Catch and Release: Reaction Dynamics from a Freed "Tension Trapped Transition State" Authors: Wang, J ; Ong, M T ; Kouznetsova, T B ; Lenhardt, J M ; Martinez, T J ; Craig, ...

  18. Light Trapping, Absorption and Solar Energy Harvesting by Artificial Materials

    SciTech Connect (OSTI)

    John, Sajeev

    2014-08-15

    We provide designs of thin-film solar cells utilizing optimized photonic-crystal light-trapping and numerical simulations of their solar-to-electrical power conversion efficiencies.

  19. Stories of Discovery & Innovation: Trapping the Light Fantastic...

    Office of Science (SC) Website

    Trapping the Light Fantastic Energy Frontier Research Centers (EFRCs) EFRCs Home Centers ... Print Text Size: A A A Subscribe FeedbackShare Page New solar cell design uses advanced ...

  20. DOE - NNSA/NFO -- News & Views Accident Trap

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

    Accident Traps Four Workers 1,800 Feet below Ground Photo - rescue from 1,800 feet below ... Thousands of workers have completed millions of accident-free hours at this heavy industry ...

  1. Electron source for a mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  2. Electron source for a mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, D.D.; Keville, R.F.

    1995-12-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  3. Inspect and Repair Steam Traps - Steam Tip Sheet #1

    SciTech Connect (OSTI)

    2012-01-31

    This revised AMO tip sheet on inspecting and repairing steam traps provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

  4. Polish permian basin: Lithofacies traps for gas within the Rotliegende deposits as a new exploration potential

    SciTech Connect (OSTI)

    Karnkowski, P.H. )

    1993-09-01

    Rotliegende deposits are the most prospective reservoir gas rocks in the Polish Permian basin. Thirty years of their exploration have led to location of numerous gas fields in the upper-most part of these series, particularly in the area of the Fore-Sudetic monocline. Up to this time, exploration studies concentrated mainly on structural objects, and most of the structures were positive gas traps. Well and seismic data also indicate an occurrence of lithofacies gas traps; they occur mainly in the sandstone zones within the fanglomerates surrounding the Wolsztyn Ridge. When comparing the facies regularities in the known gas fields in the German Permian basin (interfingering sandstones and claystones) to the facies patterns of the Polish Permian basin, one may suspect similar exploration possibilities. These are the first promising results. Advances in analysis of the Rotliegende depositional systems will enable us to create a new exploration potential.

  5. Electrostatic ion beam trap for electron collision studies

    SciTech Connect (OSTI)

    Heber, O.; Witte, P.D.; Diner, A.; Bhushan, K.G.; Strasser, D.; Toker, Y.; Rappaport, M.L.; Ben-Itzhak, I.; Altstein, N.; Schwalm, D.; Wolf, A.; Zajfman, D.

    2005-01-01

    We describe a system combining an ion beam trap and a low energy electron target in which the interaction between electrons and vibrationally cold molecular ions and clusters can be studied. The entire system uses only electrostatic fields for both trapping and focusing, thus being able to store particles without a mass limit. Preliminary results for the electron impact neutralization of C{sub 2}{sup -} ions and aluminum clusters are presented.

  6. Grooved impactor and inertial trap for sampling inhalable particulate matter

    DOE Patents [OSTI]

    Loo, Billy W.

    1984-01-01

    An inertial trap and grooved impactor for providing a sharp cutoff for particles over 15 microns from entering an inhalable particulate sampler. The impactor head has a tapered surface and is provided with V-shaped grooves. The tapered surface functions for reducing particle blow-off or reentrainment while the grooves prevent particle bounce. Water droplets and any resuspended material over the 15 micron size are collected by the inertial trap and deposited in a reservoir associated with the impactor.

  7. PowerTrap: Ultrafine PM Control without Performance Penalties | Department

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

    of Energy PowerTrap: Ultrafine PM Control without Performance Penalties PowerTrap: Ultrafine PM Control without Performance Penalties 2003 DEER Conference Presentation: Per-Tec Ltd, University of Manchester 2003_deer_kukla.pdf (693.04 KB) More Documents & Publications Plasmatron Fuel Reformer Development and Internal Combustion Engine Vehicle Applications Review of Diesel Emission Control Technology Active Soot Filter Regeneration

  8. First Use of High Charge States for Mass Measurements of Short-Lived Nuclides in a Penning Trap

    SciTech Connect (OSTI)

    Ettenauer, S.; Gallant, A. T.; Dilling, J.; Simon, M. C.; Chaudhuri, A.; Mane, E.; Delheij, P.; Pearson, M. R.; Brunner, T.; Chowdhury, U.; Simon, V. V.; Brodeur, M.; Andreoiu, C.; Audi, G.; Lopez-Urrutia, J. R. Crespo; Ullrich, J.; Gwinner, G.; Lapierre, A.; Lunney, D.; Ringle, R.

    2011-12-30

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {beta} emitter {sup 74}Rb (T{sub 1/2}=65 ms). The determination of its atomic mass and an improved Q{sub EC} value are presented.

  9. Mechanisms affecting swelling in alloys with precipitates

    SciTech Connect (OSTI)

    Mansur, L.K.; Haynes, M.R.; Lee, E.H.

    1980-01-01

    In alloys under irradiation many mechanisms exist that couple phase instability to cavity swelling. These are compounded with the more familiar mechanisms associated with point defect behavior and the evolution of microstructure. The mechanisms may be classified according to three modes of operation. Some affect cavity swelling directly by cavity-precipitate particle association, others operate indirectly by precipitate-induced changes in sinks other than cavities and finally there are mechanisms that are mediated by precipitate-induced changes in the host matrix. The physics of one mechanism of each type is developed in detail and the results compared where possible to experimental measurements. In particular, we develop the theory necessary to treat the effects on swelling of precipitation-induced changes in overall sink density; precipitation-induced changes in point defect trapping by solute depletion and creation of precipitate particle-matrix interfacial trap sites.

  10. EBIT (Electron Beam Ion Trap), N-Division Experimental Physics. Annual report, 1994

    SciTech Connect (OSTI)

    Schneider, D.

    1995-10-01

    The experimental groups in the Electron Beam Ion Trap (EBIT) program continue to perform front-line research with trapped and extracted highly charged ions (HCI) in the areas of ion/surface interactions, atomic spectroscopy, electron-ion interaction and structure measurements, highly charged ion confinement, and EBIT development studies. The ion surface/interaction studies which were initiated five years ago have reached a stage where they an carry out routine investigations, as well as produce breakthrough results towards the development of novel nanotechnology. At EBIT and SuperEBIT studies of the x-ray emission from trapped ions continue to produce significant atomic structure data with high precision for few electron systems of high-Z ions. Furthermore, diagnostics development for magnetic and laser fusion, supporting research for the x-ray laser and weapons programs, and laboratory astrophysics experiments in support of NASA`s astrophysics program are a continuing effort. The two-electron contributions to the binding energy of helium like ions were measured for the first time. The results are significant because their precision is an order of magnitude better than those of competing measurements at accelerators, and the novel technique isolates the energy corrections that are the most interesting. The RETRAP project which was initiated three years ago has reached a stage where trapping, confining and electronic cooling of HCI ions up to Th{sup 80+} can be performed routinely. Measurements of the rates and cross sections for electron transfer from H{sub 2} performed to determine the lifetime of HCI up to Xe{sup q+} and Th{sup q+} (35 {le} q {le} 80) have been studied at mean energies estimated to be {approximately} 5 q eV. This combination of heavy ions with very high charges and very low energies is rare in nature, but may be encountered in planned fusion energy demonstration devices, in highly charged ion sources, or in certain astrophysical events.

  11. Low power zinc-oxide based charge trapping memory with embedded silicon nanoparticles via poole-frenkel hole emission

    SciTech Connect (OSTI)

    El-Atab, Nazek; Nayfeh, Ammar; Ozcan, Ayse; Alkis, Sabri; Okyay, Ali K.; Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara

    2014-01-06

    A low power zinc-oxide (ZnO) charge trapping memory with embedded silicon (Si) nanoparticles is demonstrated. The charge trapping layer is formed by spin coating 2?nm silicon nanoparticles between Atomic Layer Deposited ZnO steps. The threshold voltage shift (?V{sub t}) vs. programming voltage is studied with and without the silicon nanoparticles. Applying ?1?V for 5?s at the gate of the memory with nanoparticles results in a ?V{sub t} of 3.4?V, and the memory window can be up to 8?V with an excellent retention characteristic (>10 yr). Without nanoparticles, at ?1?V programming voltage, the ?V{sub t} is negligible. In order to get ?V{sub t} of 3.4?V without nanoparticles, programming voltage in excess of 10?V is required. The negative voltage on the gate programs the memory indicating that holes are being trapped in the charge trapping layer. In addition, at 1?V the electric field across the 3.6?nm tunnel oxide is calculated to be 0.36 MV/cm, which is too small for significant tunneling. Moreover, the ?V{sub t} vs. electric field across the tunnel oxide shows square root dependence at low fields (E??2.7 MV/cm). This indicates that Poole-Frenkel Effect is the main mechanism for holes emission at low fields and Phonon Assisted Tunneling at higher fields.

  12. Recent progress in tailoring trap-based positron beams

    SciTech Connect (OSTI)

    Natisin, M. R.; Hurst, N. C.; Danielson, J. R.; Surko, C. M.

    2013-03-19

    Recent progress is described to implement two approaches to specially tailor trap-based positron beams. Experiments and simulations are presented to understand the limits on the energy spread and pulse duration of positron beams extracted from a Penning-Malmberg (PM) trap after the particles have been buffer-gas cooled (or heated) in the range of temperatures 1000 {>=} T {>=} 300 K. These simulations are also used to predict beam performance for cryogenically cooled positrons. Experiments and simulations are also presented to understand the properties of beams formed when plasmas are tailored in a PM trap in a 5 tesla magnetic field, then non-adiabatically extracted from the field using a specially designed high-permeability grid to create a new class of electrostatically guided beams.

  13. Computer analysis of sodium cold trap design and performance. [LMFBR

    SciTech Connect (OSTI)

    McPheeters, C.C.; Raue, D.J.

    1983-11-01

    Normal steam-side corrosion of steam-generator tubes in Liquid Metal Fast Breeder Reactors (LMFBRs) results in liberation of hydrogen, and most of this hydrogen diffuses through the tubes into the heat-transfer sodium and must be removed by the purification system. Cold traps are normally used to purify sodium, and they operate by cooling the sodium to temperatures near the melting point, where soluble impurities including hydrogen and oxygen precipitate as NaH and Na/sub 2/O, respectively. A computer model was developed to simulate the processes that occur in sodium cold traps. The Model for Analyzing Sodium Cold Traps (MASCOT) simulates any desired configuration of mesh arrangements and dimensions and calculates pressure drops and flow distributions, temperature profiles, impurity concentration profiles, and impurity mass distributions.

  14. Optical lattice clock with atoms confined in a shallow trap

    SciTech Connect (OSTI)

    Lemonde, Pierre; Wolf, Peter

    2005-09-15

    We study the trap depth requirement for the realization of an optical clock using atoms confined in a lattice. We show that site-to-site tunneling leads to a residual sensitivity to the atom dynamics hence requiring large depths [(50-100)E{sub r} for Sr] to avoid any frequency shift or line broadening of the atomic transition at the 10{sup -17}-10{sup -18} level. Such large depths and the corresponding laser power may, however, lead to difficulties (e.g., higher-order light shifts, two-photon ionization, technical difficulties) and therefore one would like to operate the clock in much shallower traps. To circumvent this problem we propose the use of an accelerated lattice. Acceleration lifts the degeneracy between adjacents potential wells which strongly inhibits tunneling. We show that using the Earth's gravity, much shallower traps (down to 5E{sub r} for Sr) can be used for the same accuracy goal.

  15. Self-Similar Nonlinear Dynamical Solutions for One-Component Nonneutral Plasma in a Time-Dependent Linear Focusing Field

    SciTech Connect (OSTI)

    Hong Qin and Ronald C. Davidson

    2011-07-19

    In a linear trap confining a one-component nonneutral plasma, the external focusing force is a linear function of the configuration coordinates and/or the velocity coordinates. Linear traps include the classical Paul trap and the Penning trap, as well as the newly proposed rotating-radio- frequency traps and the Mobius accelerator. This paper describes a class of self-similar nonlinear solutions of nonneutral plasma in general time-dependent linear focusing devices, with self-consistent electrostatic field. This class of nonlinear solutions includes many known solutions as special cases.

  16. Electron beam ion source and electron beam ion trap (invited)

    SciTech Connect (OSTI)

    Becker, Reinard [Scientific Software Service, Kapellenweg 2a, D-63571 Gelnhausen (Germany); Kester, Oliver [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)

    2010-02-15

    The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not ''sorcery'' but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future.

  17. Three dimensional separation trap based on dielectrophoresis and use thereof

    DOE Patents [OSTI]

    Mariella, Jr., Raymond P.

    2004-05-04

    An apparatus is adapted to separate target materials from other materials in a flow containing the target materials and other materials. A dielectrophoretic trap is adapted to receive the target materials and the other materials. At least one electrode system is provided in the trap. The electrode system has a three-dimensional configuration. The electrode system includes a first electrode and a second electrode that are shaped and positioned relative to each such that application of an electrical voltage to the first electrode and the second electrode creates a dielectrophoretic force and said dielectrophoretic force does not reach zero between the first electrode and the second electrode.

  18. Stochastic processes of particle trapping and detrapping by a wave in a magnetized plasma

    SciTech Connect (OSTI)

    Zaslavsky, A.; Krafft, C.; Volokitin, A.

    2006-01-15

    This paper presents some relevant numerical simulations of the three-dimensional evolution of a monochromatic lower hybrid wave interacting at the Landau resonance with a Maxwellian electron beam in a magnetized plasma. A statistical study of the stochastic trapping-detrapping transitions performed by a large set of quasiresonant test particles moving self-consistently in the wave's potential has been carried out using dynamical criteria based on simple physical arguments. The paper allows us to explain the role of the stochastic processes at work in the wave-particle interactions and to shed light on their influence on the dynamical evolution of the system over a long range of time.

  19. Differentially pumped dual linear quadrupole ion trap mass spectrometer

    DOE Patents [OSTI]

    Owen, Benjamin C.; Kenttamaa, Hilkka I.

    2015-10-20

    The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

  20. Single particle density of trapped interacting quantum gases

    SciTech Connect (OSTI)

    Bala, Renu; Bosse, J.; Pathak, K. N.

    2015-05-15

    An expression for single particle density for trapped interacting gases has been obtained in first order of interaction using Greens function method. Results are easily simplified for homogeneous quantum gases and are found to agree with famous results obtained by Huang-Yang-Luttinger and Lee-Yang.

  1. An extension of the multiple-trapping model

    SciTech Connect (OSTI)

    Shkilev, V. P.

    2012-07-15

    The hopping charge transport in disordered semiconductors is considered. Using the concept of the transport energy level, macroscopic equations are derived that extend a multiple-trapping model to the case of semiconductors with both energy and spatial disorders. It is shown that, although both types of disorder can cause dispersive transport, the frequency dependence of conductivity is determined exclusively by the spatial disorder.

  2. Extremely scaled high-k/In?.??Ga?.??As gate stacks with low leakage and low interface trap densities

    SciTech Connect (OSTI)

    Chobpattana, Varistha; Mikheev, Evgeny; Zhang, Jack Y.; Mates, Thomas E.; Stemmer, Susanne

    2014-09-28

    Highly scaled gate dielectric stacks with low leakage and low interface trap densities are required for complementary metal-oxide-semiconductor technology with III-V semiconductor channels. Here, we show that a novel pre-deposition technique, consisting of alternating cycles of nitrogen plasma and tetrakis(dimethylamino)titanium, allows for HfO? and ZrO? gate stacks with extremely high accumulation capacitance densities of more than 5 ?F/cm? at 1 MHz, low leakage current, low frequency dispersion, and low midgap interface trap densities (10cm?eV?range). Using x-ray photoelectron spectroscopy, we show that the interface contains TiO? and small quantities of In?O?, but no detectable Ga- or As-oxides, or As-As bonding. The results allow for insights into the microscopic mechanisms that control leakage and frequency dispersion in high-k/III-V gate stacks.

  3. Hole Trapping at Surfaces of m?ZrO2 and m?HfO2 Nanocrystals

    SciTech Connect (OSTI)

    Wolf, Matthew J.; Mckenna, Keith P.; Shlyuger, Alexander L.

    2012-12-03

    We investigate hole trapping at the most prevalent facets of monoclinic zirconia (m-ZrO2) and hafnia (m-HfO2) nanocrystals using first-principles methods. The localization of holes at surface oxygen ions is more favorable than in the bulk crystal by up to ?1 eV. This is caused mainly by the reduction of the absolute value of the electrostatic potential at the surface ions with respect to the bulk and by the significant surface distortion caused by the hole localization. The mobility of holes at surfaces is much lower than that found in the bulk and is fairly isotropic. Unlike in cubic oxides, such as MgO and CaO, we do not find a significant driving force for preferential trapping of holes at steps on the m-ZrO2 surface. These fundamental results are relevant to mechanisms of water oxidation, photocatalysis, contact charging, and photodesorption.

  4. Simulation of lean NOx trap performance with microkinetic chemistry and without mass transfer.

    SciTech Connect (OSTI)

    Larson, Rich; Daw, C. Stuart; Pihl, Josh A.; Chakravarthy, V. Kalyana

    2011-08-01

    A microkinetic chemical reaction mechanism capable of describing both the storage and regeneration processes in a fully formulated lean NO{sub x} trap (LNT) is presented. The mechanism includes steps occurring on the precious metal, barium oxide (NO{sub x} storage), and cerium oxide (oxygen storage) sites of the catalyst. The complete reaction set is used in conjunction with a transient plug flow reactor code to simulate not only conventional storage/regeneration cycles with a CO/H{sub 2} reductant, but also steady flow temperature sweep experiments that were previously analyzed with just a precious metal mechanism and a steady state code. The results show that NO{sub x} storage is not negligible during some of the temperature ramps, necessitating a re-evaluation of the precious metal kinetic parameters. The parameters for the entire mechanism are inferred by finding the best overall fit to the complete set of experiments. Rigorous thermodynamic consistency is enforced for parallel reaction pathways and with respect to known data for all of the gas phase species involved. It is found that, with a few minor exceptions, all of the basic experimental observations can be reproduced with these purely kinetic simulations, i.e., without including mass-transfer limitations. In addition to accounting for normal cycling behavior, the final mechanism should provide a starting point for the description of further LNT phenomena such as desulfation and the role of alternative reductants.

  5. Enhanced memory effect with embedded graphene nanoplatelets in ZnO charge trapping layer

    SciTech Connect (OSTI)

    El-Atab, Nazek; Nayfeh, Ammar; Cimen, Furkan; Alkis, Sabri; Okyay, Ali K.

    2014-07-21

    A charge trapping memory with graphene nanoplatelets embedded in atomic layer deposited ZnO (GNIZ) is demonstrated. The memory shows a large threshold voltage V{sub t} shift (4?V) at low operating voltage (6/?6?V), good retention (>10 yr), and good endurance characteristic (>10{sup 4} cycles). This memory performance is compared to control devices with graphene nanoplatelets (or ZnO) and a thicker tunnel oxide. These structures showed a reduced V{sub t} shift and retention characteristic. The GNIZ structure allows for scaling down the tunnel oxide thickness along with improving the memory window and retention of data. The larger V{sub t} shift indicates that the ZnO adds available trap states and enhances the emission and retention of charges. The charge emission mechanism in the memory structures with graphene nanoplatelets at an electric field E???5.57 MV/cm is found to be based on Fowler-Nordheim tunneling. The fabrication of this memory device is compatible with current semiconductor processing, therefore, has great potential in low-cost nano-memory applications.

  6. Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study...

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

    Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study on Sulfur Effects Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study on Sulfur Effects Presentation given ...

  7. SulfaTrap(tm): Novel Sorbent to Clean Biogas for Fuel Cell Combined...

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

    SulfaTrap(tm): Novel Sorbent to Clean Biogas for Fuel Cell Combined Heat and Power SulfaTrap(tm): Novel Sorbent to Clean Biogas for Fuel Cell Combined Heat and Power Improving ...

  8. Narrowing of the coherent population trapping resonance under zone pumping in cells with different characteristics of the wall coating

    SciTech Connect (OSTI)

    Kazakov, G A; Litvinov, A N; Matisov, B G [St. Petersburg State Polytechnic University, St. Petersburg (Russian Federation)

    2012-02-28

    It is shown that when coherent population trapping (CPT) resonance is excited by a narrow laser beam, the presence of elastic collisions with the cell wall significantly affects the line shape of the CPT-resonance. We have constructed a theoretical model, which is based on averaging over the random Ramsey sequences of the atom dwell time in the beam and dark zones and takes into account the probability of elastic bounce of an atom from the wall.

  9. Enumeration of Juvenile Salmonids in the Okanogan Basin Using Rotary Screw Traps, Performance Period: March 15, 2006 - July 15, 2006.

    SciTech Connect (OSTI)

    Johnson, Peter N.; Rayton, Michael D.

    2007-05-01

    The Colville Tribes identified the need for collecting baseline census data on the timing and abundance of juvenile salmonids in the Okanogan River basin for the purpose of documenting local fish populations, augmenting existing fishery data and assessing natural production trends of salmonids. This report documents and assesses the pilot year of rotary trap capture of salmonid smolts on the Okanogan River. The project is a component of the Colville Tribes Okanogan Basin Monitoring and Evaluation Program (OBMEP) which began in 2004. Trapping for outmigrating fish began on 14 March 2006 and continued through 11 July 2006. Anadromous forms of Oncorhynchus, including summer steelhead (O. mykiss), Chinook (O. tshawytscha), and sockeye (O. nerka), were targeted for this study; all have verified, natural production in the Okanogan basin. Both 8-ft and 5-ft rotary screw traps were deployed on the Okanogan River from the Highway 20 Bridge and typically fished during evening hours or 24 hours per day, depending upon trap position and discharge conditions. Juvenile Chinook salmon were the most abundant species trapped in 2006 (10,682 fry and 2,024 smolts), followed by sockeye (205 parr and 3,291 smolts) and steelhead (1 fry and 333 smolts). Of the trapped Chinook, all fry were wild origin and all but five of the smolts were hatchery-reared. All trapped sockeye were wild origin and 88% of the steelhead smolts were hatchery-reared. Mark-recapture experiments were conducted using Chinook fry and hatchery-reared steelhead smolts (sockeye were not used in 2006 because the peak of the juvenile migration occurred prior to the onset of the mark-recapture experiments). A total of 930 chinook fry were marked and released across eight separate release dates (numbers of marked Chinook fry released per day ranged from 34 to 290 fish). A total of 11 chinook fry were recaptured for an overall trap efficiency of 1.18%. A total of 710 hatchery-reared steelhead were marked and released across

  10. Bose gas in a single-beam optical dipole trap

    SciTech Connect (OSTI)

    Simon, Lena; Strunz, Walter T.

    2010-06-15

    We study an ultracold Bose gas in an optical dipole trap consisting of one single focused laser beam. An analytical expression for the corresponding density of states beyond the usual harmonic approximation is obtained. We are thus able to discuss the existence of a critical temperature for Bose-Einstein condensation and find that the phase transition must be enabled by a cutoff near the threshold. Moreover, we study the dynamics of evaporative cooling and observe significant deviations from the findings for the well-established harmonic approximation. Furthermore, we investigate Bose-Einstein condensates in such a trap in Thomas-Fermi approximation and determine analytical expressions for chemical potential, internal energy, and Thomas-Fermi radii beyond the usual harmonic approximation.