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Sample records for microearthquake shear-wave splitting

  1. Shear-wave splitting and reservoir crack characterization: the...

    Open Energy Info (EERE)

    of its geothermal potential and day-to-day production. To detect the geometry and density of fracture systems we applied the shear-wave splitting technique to a large number...

  2. Micro-Earthquake At Coso Geothermal Area (2005) | Open Energy...

    Open Energy Info (EERE)

    at The Geysers and Coso Geothermal Reservoirs by Shear-wave Splitting, Rial, Elkibbi, Yang and Pereyra. The raw data for the project consists of seismographic recordings of...

  3. Micro-Earthquake At Geysers Area (Laney, 2005) | Open Energy...

    Open Energy Info (EERE)

    at The Geysers and Coso Geothermal Reservoirs by Shear-wave Splitting, Rial, Elkibbi, Yang and Pereyra. The raw data for the project consists of seismographic recordings of...

  4. Shear waves in acoustic anisotropic media (Journal Article) ...

    Office of Scientific and Technical Information (OSTI)

    Shear waves in acoustic anisotropic media Citation Details In-Document Search Title: Shear waves in acoustic anisotropic media Acoustic transversely isotropic (TI) media are ...

  5. Microearthquake Technology for EGS Fracture Characterization...

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

    Microearthquake Technology for EGS Fracture Characterization; 2010 Geothermal Technology Program Peer Review Report Microearthquake Technology for EGS Fracture Characterization; ...

  6. Anomalous shear wave attenuation in the shallow crust beneath...

    Open Energy Info (EERE)

    volcanic region, California Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Anomalous shear wave attenuation in the shallow crust beneath the...

  7. Micro-Earthquake At Coso Geothermal Area (2002-2005) | Open Energy...

    Open Energy Info (EERE)

    reservoir crack characterization: the Coso geothermal field Rial, J.A.; Elkibbi, M.; Yang, M. (1 January 2005) Shear-wave splitting as a tool for the characterization of...

  8. Micro-Earthquake At Coso Geothermal Area (1992-1997) | Open Energy...

    Open Energy Info (EERE)

    processed. From the delay time of split shear waves, it was estimated that the crack density in the most active geothermal reservoir area (above 3 km depth) ranges between 0.030...

  9. Piezoelectric shear wave resonator and method of making same

    DOE Patents [OSTI]

    Wang, Jin S.; Lakin, Kenneth M.; Landin, Allen R.

    1988-01-01

    An acoustic shear wave resonator comprising a piezoelectric film having its C-axis substantially inclined from the film normal such that the shear wave coupling coefficient significantly exceeds the longitudinal wave coupling coefficient, whereby the film is capable of shear wave resonance, and means for exciting said film to resonate. The film is prepared by deposition in a dc planar magnetron sputtering system to which a supplemental electric field is applied. The resonator structure may also include a semiconductor material having a positive temperature coefficient of resonance such that the resonator has a temperature coefficient of resonance approaching 0 ppm/.degree.C.

  10. Method of making a piezoelectric shear wave resonator

    DOE Patents [OSTI]

    Wang, Jin S.; Lakin, Kenneth M.; Landin, Allen R.

    1987-02-03

    An acoustic shear wave resonator comprising a piezoelectric film having its C-axis substantially inclined from the film normal such that the shear wave coupling coefficient significantly exceeds the longitudinal wave coupling coefficient, whereby the film is capable of shear wave resonance, and means for exciting said film to resonate. The film is prepared by deposition in a dc planar magnetron sputtering system to which a supplemental electric field is applied. The resonator structure may also include a semiconductor material having a positive temperature coefficient of resonance such that the resonator has a temperature coefficient of resonance approaching 0 ppm/.degree.C.

  11. Piezoelectric shear wave resonator and method of making same

    DOE Patents [OSTI]

    Wang, J.S.; Lakin, K.M.; Landin, A.R.

    1985-05-20

    An acoustic shear wave resonator comprising a piezoelectric film having its C-axis substantially inclined from the film normal such that the shear wave coupling coefficient significantly exceeds the longitudinal wave coupling coefficient, whereby the film is capable of shear wave resonance, and means for exciting said film to resonate. The film is prepared by deposition in a dc planar magnetron sputtering system to which a supplemental electric field is applied. The resonator structure may also include a semiconductor material having a positive temperature coefficient of resonance such that the resonator has a temperature coefficient of resonance approaching 0 ppM//sup 0/C.

  12. Piezoelectric shear wave resonator and method of making same

    DOE Patents [OSTI]

    Wang, J.S.; Lakin, K.M.; Landin, A.R.

    1983-10-25

    An acoustic shear wave resonator comprising a piezoelectric film having its C-axis substantially inclined from the film normal such that the shear wave coupling coefficient significantly exceeds the longitudinal wave coupling coefficient, whereby the film is capable of shear wave resonance, and means for exciting said film to resonate. The film is prepared by deposition in a dc planar magnetron sputtering system to which a supplemental electric field is applied. The resonator structure may also include a semiconductor material having a positive temperature coefficient of resonance such that the resonator has a temperature coefficient of resonance approaching 0 ppM//sup 0/C.

  13. Microearthquake Technology for EGS Fracture Characterization | Department

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

    of Energy Microearthquake Technology for EGS Fracture Characterization Microearthquake Technology for EGS Fracture Characterization Project objectives: To understand how EGS fracture networks develop; To develop technology to determine accurate absolute three-dimensional positions of EGS fracture networks. PDF icon seismic_foulger_microearthquake.pdf More Documents & Publications Creation of an Engineered Geothermal System through Hydraulic and Thermal Stimulation Newberry EGS

  14. Micro-Earthquake At Snake River Plain Geothermal Region (1976...

    Open Energy Info (EERE)

    Micro-Earthquake At Snake River Plain Geothermal Region (1976) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At Snake River...

  15. Micro-Earthquake At Northwest Basin and Range Geothermal Region...

    Open Energy Info (EERE)

    Micro-Earthquake At Northwest Basin and Range Geothermal Region (1976) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At...

  16. Micro-Earthquake At Geysers Area (Erten & Rial, 1999) | Open...

    Open Energy Info (EERE)

    Micro-Earthquake At Geysers Area (Erten & Rial, 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At Geysers Area (Erten &...

  17. Conducting a 3D Converted Shear Wave Project to Reduce Exploration Risk at Wister, CA

    Broader source: Energy.gov [DOE]

    DOE Geothermal Technologies Peer Review 2010 - Presentation. The primary objective of this project is to conduct a 3C 3D (converted shear wave) seismic survey to reduce exploration risk by characterizing fault and fracture geometrics at Wister, CA.The intent of the proposed program is to use a 3D seismic survey with converted shear waves combined with other available data to site and drill production wells at Wister, a blind geothermal resource.

  18. Shear-wave splitting as a tool for the characterization of geothermal...

    Open Energy Info (EERE)

    extensions, from nearly a decade of practice. Authors Rial, J.A.; Elkibbi, M.; Yang and M. Published Journal Geothermics, 112005 DOI http:dx.doi.org10.1016...

  19. Microearthquake surveys of Snake River plain and Northwest Basin...

    Open Energy Info (EERE)

    microearthquakes; Nevada; North America; passive systems; Pershing County Nevada; Raft River; reservoir rocks; seismic methods; seismicity; seismology; Snake River plain;...

  20. Apparatus for checking the direction of polarization of shear-wave ultrasonic transducers

    DOE Patents [OSTI]

    Karplus, Henry H. B.

    1980-01-01

    An apparatus for checking the direction of polarization of shear-wave ultrasonic transducers comprises a first planar surface for mounting the shear-wave transducer, a second planar surface inclined at a predetermined angle to the first surface to generate longitudinal waves by mode conversion, and a third planar surface disposed at a second predetermined angle to the first for mounting a longitudinal-wave ultrasonic transducer. In an alternate embodiment, two second planar surfaces at the predetermined angle are placed at an angle to each other. The magnitude of the shear wave is a function of the angle between the direction of polarization of the transducer and the mode-conversion surface.

  1. Data interpretation of joint compressional and shear wave survey in mountainous region

    SciTech Connect (OSTI)

    Fugiu, D. )

    1992-01-01

    The join utilization of compressional and shear wave data leads one to discover nonstructural hydrocarbon traps such as stratigraphic trap, lithologic trap, fracture trap, etc. and to ascertain fluid situation in formation, lithologic variation and fracture zone, so that the accuracy of seismic data interpretation is improved greatly. In this paper, the author describes how to determine shear wave horizon, how to interpret carbonate reservoir and how to discover gas accumulation zone in HBC area in Sichuan Province. It is very important to pay more attention to analyzing the ratio between compressional wave amplitude and shear wave amplitude, and the ratio between compressional wave velocity and shear wave velocity in data interpretation. The amplitude ratio anomaly and the velocity ratio anomaly in HBC area can be usually seen at anticlinal axis areas and small noses. Generally speaking, the amplitude ratio anomaly area reflects gas accumulation and the velocity ratio anomaly area exhibits dense fracture zone. Good results have been obtained from exploratory wells in the areas where there occur the two anomalies simultaneously.

  2. Micro-Earthquake At Coso Geothermal Area (2007) | Open Energy...

    Open Energy Info (EERE)

    area Julian, B.R.; Foulger, G.R. (1 January 2010) IMPROVED METHODS FOR MAPPING PERMEABILITY AND HEAT SOURCES IN GEOTHERMAL AREAS USING MICROEARTHQUAKE DATA Additional...

  3. Micro-Earthquake At Raft River Geothermal Area (1979) | Open...

    Open Energy Info (EERE)

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At Raft River Geothermal Area (1979) Exploration Activity Details Location Raft River...

  4. Micro-Earthquake At Raft River Geothermal Area (2011) | Open...

    Open Energy Info (EERE)

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At Raft River Geothermal Area (2011) Exploration Activity Details Location Raft River...

  5. Micro-Earthquake At Dixie Valley Geothermal Area (Katz & J.,...

    Open Energy Info (EERE)

    Dixie Valley Geothermal Area (Katz & J., 1984) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At Dixie Valley Geothermal Area...

  6. Micro-Earthquake At Kilauea East Rift Geothermal Area (Thomas...

    Open Energy Info (EERE)

    At Kilauea East Rift Geothermal Area (Thomas, 1986) Exploration Activity Details Location Kilauea East Rift Geothermal Area Exploration Technique Micro-Earthquake Activity...

  7. Micro-Earthquake At Long Valley Caldera Geothermal Area (Stroujkova...

    Open Energy Info (EERE)

    Micro-Earthquake At Long Valley Caldera Geothermal Area (Stroujkova & Malin, 2001) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity:...

  8. Micro-Earthquake At Brady Hot Springs Geothermal Area (2011)...

    Open Energy Info (EERE)

    At Brady Hot Springs Geothermal Area (2011) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At Brady Hot Springs Geothermal Area...

  9. Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves

    SciTech Connect (OSTI)

    IceCube Collaboration; Klein, Spencer

    2009-06-04

    We have measured the speed of both pressure waves and shear waves as a function of depth between 80 and 500 m depth in South Pole ice with better than 1% precision. The measurements were made using the South Pole Acoustic Test Setup (SPATS), an array of transmitters and sensors deployed in the ice at the South Pole in order to measure the acoustic properties relevant to acoustic detection of astrophysical neutrinos. The transmitters and sensors use piezoceramics operating at {approx}5-25 kHz. Between 200 m and 500 m depth, the measured profile is consistent with zero variation of the sound speed with depth, resulting in zero refraction, for both pressure and shear waves. We also performed a complementary study featuring an explosive signal propagating vertically from 50 to 2250 m depth, from which we determined a value for the pressure wave speed consistent with that determined for shallower depths, higher frequencies, and horizontal propagation with the SPATS sensors. The sound speed profile presented here can be used to achieve good acoustic source position and emission time reconstruction in general, and neutrino direction and energy reconstruction in particular. The reconstructed quantities could also help separate neutrino signals from background.

  10. Micro-Earthquake At Marysville Mt Area (Blackwell) | Open Energy...

    Open Energy Info (EERE)

    observed in the geothermal areas in the Salton Sea between 1-10 Hz (in units of power density). Because of this very low background noise the micro-earthquake survey was possible...

  11. Micro-Earthquake At Under Steamboat Springs Area (Warpinski,...

    Open Energy Info (EERE)

    Technique Micro-Earthquake Activity Date Usefulness useful DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D....

  12. Microearthquake Studies at the Salton Sea Geothermal Field

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

    Templeton, Dennise

    2013-10-01

    The objective of this project is to detect and locate microearthquakes to aid in the characterization of reservoir fracture networks. Accurate identification and mapping of the large numbers of microearthquakes induced in EGS is one technique that provides diagnostic information when determining the location, orientation and length of underground crack systems for use in reservoir development and management applications. Conventional earthquake location techniques often are employed to locate microearthquakes. However, these techniques require labor-intensive picking of individual seismic phase onsets across a network of sensors. For this project we adapt the Matched Field Processing (MFP) technique to the elastic propagation problem in geothermal reservoirs to identify more and smaller events than traditional methods alone.

  13. Microearthquake Studies at the Salton Sea Geothermal Field

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

    Templeton, Dennise

    The objective of this project is to detect and locate microearthquakes to aid in the characterization of reservoir fracture networks. Accurate identification and mapping of the large numbers of microearthquakes induced in EGS is one technique that provides diagnostic information when determining the location, orientation and length of underground crack systems for use in reservoir development and management applications. Conventional earthquake location techniques often are employed to locate microearthquakes. However, these techniques require labor-intensive picking of individual seismic phase onsets across a network of sensors. For this project we adapt the Matched Field Processing (MFP) technique to the elastic propagation problem in geothermal reservoirs to identify more and smaller events than traditional methods alone.

  14. Shear Wave Velocity Structure of Southern African Crust: Evidence for Compositional Heterogeneity within Archaean and Proterozoic Terrains

    SciTech Connect (OSTI)

    Kgaswane, E M; Nyblade, A A; Julia, J; Dirks, P H H M; Durrheim, R J; Pasyanos, M E

    2008-11-11

    Crustal structure in southern Africa has been investigated by jointly inverting receiver functions and Rayleigh wave group velocities for 89 broadband seismic stations spanning much of the Precambrian shield of southern Africa. 1-D shear wave velocity profiles obtained from the inversion yield Moho depths that are similar to those reported in previous studies and show considerable variability in the shear wave velocity structure of the lower part of the crust between some terrains. For many of the Archaean and Proterozoic terrains in the shield, S velocities reach 4.0 km/s or higher over a substantial part of the lower crust. However, for most of the Kimberley terrain and adjacent parts of the Kheis Province and Witwatersrand terrain, as well as for the western part of the Tokwe terrain, mean shear wave velocities of {le} 3.9 km/s characterize the lower part of the crust along with slightly ({approx}5 km) thinner crust. These findings indicate that the lower crust across much of the shield has a predominantly mafic composition, except for the southwest portion of the Kaapvaal Craton and western portion of the Zimbabwe Craton, where the lower crust is intermediate-to-felsic in composition. The parts of the Kaapvaal Craton underlain by intermediate-to-felsic lower crust coincide with regions where Ventersdorp rocks have been preserved, and thus we suggest that the intermediate-to-felsic composition of the lower crust and the shallower Moho may have resulted from crustal melting during the Ventersdorp tectonomagmatic event at c. 2.7 Ga and concomitant crustal thinning caused by rifting.

  15. Micro-Earthquake At New River Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    River Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At New River Area (DOE GTP) Exploration Activity Details...

  16. Micro-Earthquake At Newberry Caldera Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Micro-Earthquake At Newberry Caldera Area (DOE GTP) Exploration Activity Details...

  17. Reservoir fracture mapping using microearthquakes: Austin chalk, Giddings field, TX and 76 field, Clinton Co., KY

    SciTech Connect (OSTI)

    Phillips, W.S.; Rutledge, J.T.; Gardner, T.L.; Fairbanks, T.D.; Miller, M.E.; Schuessler, B.K.

    1996-11-01

    Patterns of microearthquakes detected downhole defined fracture orientation and extent in the Austin chalk, Giddings field, TX and the 76 field, Clinton Co., KY. We collected over 480 and 770 microearthquakes during hydraulic stimulation at two sites in the Austin chalk, and over 3200 during primary production in Clinton Co. Data were of high enough quality that 20%, 31% and 53% of the events could be located, respectively. Reflected waves constrained microearthquakes to the stimulated depths at the base of the Austin chalk. In plan view, microearthquakes defined elongate fracture zones extending from the stimulation wells parallel to the regional fracture trend. However, widths of the stimulated zones differed by a factor of five between the two Austin chalk sites, indicating a large difference in the population of ancillary fractures. Post-stimulation production was much higher from the wider zone. At Clinton Co., microearthquakes defined low-angle, reverse-fault fracture zones above and below a producing zone. Associations with depleted production intervals indicated the mapped fractures had been previously drained. Drilling showed that the fractures currently contain brine. The seismic behavior was consistent with poroelastic models that predicted slight increases in compressive stress above and below the drained volume.

  18. Characterization and application of microearthquake clusters to problems of scaling, fault zone dynamics, and seismic monitoring at Parkfield, California

    SciTech Connect (OSTI)

    Nadeau, R.M.

    1995-10-01

    This document contains information about the characterization and application of microearthquake clusters and fault zone dynamics. Topics discussed include: Seismological studies; fault-zone dynamics; periodic recurrence; scaling of microearthquakes to large earthquakes; implications of fault mechanics and seismic hazards; and wave propagation and temporal changes.

  19. Split gland

    DOE Patents [OSTI]

    Petranto, J.J.

    1989-09-05

    A split gland having only three parts is described. The gland has substantially the same stability to the relative motion of the constituent half-gland members during the attachment process to a female fitting as have more complicated designs. Ease of manufacture and use result from the reduction in complexity of the present invention. 15 figs.

  20. Split gland

    DOE Patents [OSTI]

    Petranto, Joseph J. (Los Alamos, NM)

    1989-01-01

    A split gland having only three parts is described. The gland has substantially the same stability to the relative motion of the constituent half-gland members during the attachment process to a female fitting as have more complicated designs. Ease of manufacture and use result from the reduction in complexity of the present invention.

  1. Microearthquakes induced by a hydraulic injection in sedimentary rock, East Texas

    SciTech Connect (OSTI)

    House, L.; Flores, R.; Withers, R.

    1996-08-01

    In October, 1993, ARCO carried out a hydraulic injection near Beaumont, TX, into an unconsolidated sand, the Frio Formation. Fluid was injected into a 55m long zone at a depth of 1350 m. Four separate injections were done during 5 days. A total of more than 2.1 million gallons of bentonite slurry was injected, along with more than 3 million pounds of sand. Downhole fluid injection pressures ranged between about 3000 and 3500 psi. Induced microearthquakes were monitored by a set of 25 geophone packages situated in each of two monitoring well. More than 2400 microearthquakes were recorded during the injection, although most were too small to locate reliably using arrival times. A total of 54 microearthquakes were selected for detailed study. They were precisely located using arrival times of P and S phases from both of the monitoring boreholes. These locations are distributed non-uniformly, with a cluster near the injection borehole, a linear distribution about 200 m from the injection borehole, and a relatively quiet zone in between. The relatively nonseismic behavior in the middle zone compared to the other two zones suggests that this zone represent a discontinuity in the Frio Formation, although no obvious discontinuity has been identified from logs or nearby seismic reflection profiles. The large vertical extent of the geophone packages allowed an inversion of the arrival times for transverse isotropic elastic parameters, which yielded Vp anisotropy of about -13% and Vs of about -2%. Since these anisotropy values indicate that the vertical Vp and Vs are larger than the horizontal, they are surprising for this well bedded formation. Single-event focal mechanisms could be determined for 47 of the microearthquakes, and all are shear slip type. They show a large range of mechanisms, ranging from normal to reverse slip. Normal or oblique-normal slip predominant though, with T (tensional) axes generally nearly horizontal and approximately N-S. 3 refs., 4 figs., 1 tab.

  2. Microearthquake Study of the Salton Sea Geothermal Field, California: Evidence of Stress Triggering - Masters Thesis

    SciTech Connect (OSTI)

    Holland, Austin Adams

    2002-02-01

    A digital network of 24 seismograph stations was operated from September 15, 1987 to September 30, 1988, by Lawrence Livermore National Laboratory and Unocal as part of the Salton Sea Scientific Drilling Project to study seismicity related to tectonics and geothermal activity near the drilling site. More than 2001 microearthquakes were relocated in this study in order to image any pervasive structures that may exist within the Salton Sea geothermal field. First, detailed velocity models were obtained through standard 1-D inversion techniques. These velocity models were then used to relocate events using both single event methods and Double-Differencing, a joint hypocenter location method. An anisotropic velocity model was built from anisotropy estimates obtained from well logs within the study area. During the study period, the Superstition wills sequence occurred with two moderate earthquakes of MS 6.2 and MS 6.6. These moderate earthquakes caused a rotation of the stress field as observed from the inversion of first motion data from microearthquakes at the Salton Sea geothermal field. Coulomb failure analysis also indicates that microearthquakes occurring after the Superstition Hills sequence are located within a region of stress increase suggesting stress triggering caused by the moderate earthquakes.

  3. Thermocouple split follower

    DOE Patents [OSTI]

    Howell, deceased, Louis J.

    1980-01-01

    Thermoelectric generator assembly accommodating differential thermal expansion between thermoelectric elements by means of a cylindrical split follower forming a slot and having internal spring loaded wedges that permit the split follower to open and close across the slot.

  4. Shear wave transducer for boreholes

    DOE Patents [OSTI]

    Mao, N.H.

    1984-08-23

    A technique and apparatus is provided for estimating in situ stresses by measuring stress-induced velocity anisotropy around a borehole. Two sets each of radially and tangentially polarized transducers are placed inside the hole with displacement directions either parallel or perpendicular to the principal stress directions. With this configuration, relative travel times are measured by both a pulsed phase-locked loop technique and a cross correlation of digitized waveforms. The biaxial velocity data are used to back-calculate the applied stress.

  5. Final technical report

    SciTech Connect (OSTI)

    J.A. Rial; J. Lees

    2009-03-31

    As proposed, the main effort in this project is the development of software capable of performing real-time monitoring of micro-seismic activity recorded by an array of sensors deployed around an EGS. The main milestones are defined by the development of software to perform the following tasks: • Real-time micro-earthquake detection and location • Real-time detection of shear-wave splitting • Delayed-time inversion of shear-wave splitting These algorithms, which are discussed in detail in this report, make possible the automatic and real-time monitoring of subsurface fracture systems in geothermal fields from data collected by an array of seismic sensors. Shear wave splitting (SWS) is parameterized in terms of the polarization of the fast shear wave and the time delay between the fast and slow shear waves, which are automatically measured and stored. The measured parameters are then combined with previously measured SWS parameters at the same station and used to invert for the orientation (strike and dip) and intensity of cracks under that station. In addition, this grant allowed the collection of seismic data from several geothermal regions in the US (Coso) and Iceland (Hengill) to use in the development and testing of the software.

  6. Real-time fracture monitoring in Engineered Geothermal Systems with seismic waves

    SciTech Connect (OSTI)

    Jose A. Rial; Jonathan Lees

    2009-03-31

    As proposed, the main effort in this project is the development of software capable of performing real-time monitoring of micro-seismic activity recorded by an array of sensors deployed around an EGS. The main milestones are defined by the development of software to perform the following tasks: • Real-time micro-earthquake detection and location • Real-time detection of shear-wave splitting • Delayed-time inversion of shear-wave splitting These algorithms, which are discussed in detail in this report, make possible the automatic and real-time monitoring of subsurface fracture systems in geothermal fields from data collected by an array of seismic sensors. Shear wave splitting (SWS) is parameterized in terms of the polarization of the fast shear wave and the time delay between the fast and slow shear waves, which are automatically measured and stored. The measured parameters are then combined with previously measured SWS parameters at the same station and used to invert for the orientation (strike and dip) and intensity of cracks under that station. In addition, this grant allowed the collection of seismic data from several geothermal regions in the US (Coso) and Iceland (Hengill) to use in the development and testing of the software.

  7. Split University | Open Energy Information

    Open Energy Info (EERE)

    Name: Split University Place: Zagreb, Croatia Sector: Hydro, Solar Product: Croatia-based electrical engineering faculty of Split University. Involved in developing small hydro and...

  8. Split image optical display

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY)

    2007-05-29

    A video image is displayed from an optical panel by splitting the image into a plurality of image components, and then projecting the image components through corresponding portions of the panel to collectively form the image. Depth of the display is correspondingly reduced.

  9. Split image optical display

    DOE Patents [OSTI]

    Veligdan, James T.

    2005-05-31

    A video image is displayed from an optical panel by splitting the image into a plurality of image components, and then projecting the image components through corresponding portions of the panel to collectively form the image. Depth of the display is correspondingly reduced.

  10. Application of the Split Hopkinson Resonant Bar Test for Seismic Property Characterization of Hydrate-bearing Sand Undergoing Water Saturation

    SciTech Connect (OSTI)

    Nakagawa, S.; Kneafsey, T.J.

    2011-05-03

    Conventional resonant bar tests allow the measurement of seismic properties of rocks and sediments at low frequencies (several kilohertz). However, the tests require a long, slender sample which is often difficult to obtain from the deep subsurface and weak and fractured formations. We present an alternative low-frequency measurement technique to the conventional resonant bar tests. This technique involves a jacketed core sample placed between a pair of long, metal extension rods with attached seismic source and receiver—the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the added length and mass to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The proposed “Split Hopkinson Resonant Bar (SHRB)” test is applied in two steps. In the first step, extension and torsion-mode resonance frequencies and attenuation of the system are measured. Then, numerical inversions for the compressional and shear wave velocities and attenuation are performed. We initially applied the SHRB test to synthetic materials (plastics) for testing its accuracy, then used it for measuring the seismic velocities and attenuation of a rock core containing supercritical CO{sub 2}, and a sediment core while methane hydrate formed in the pore space.

  11. Analysis of Injection-Induced Micro-Earthquakes in a Geothermal Steam Reservoir, The Geysers Geothermal Field, California

    SciTech Connect (OSTI)

    Rutqvist, Jonny; Rutqvist, J.; Oldenburg, C.M.

    2008-05-15

    In this study we analyze relative contributions to the cause and mechanism of injection-induced micro-earthquakes (MEQs) at The Geysers geothermal field, California. We estimated the potential for inducing seismicity by coupled thermal-hydrological-mechanical analysis of the geothermal steam production and cold water injection to calculate changes in stress (in time and space) and investigated if those changes could induce a rock mechanical failure and associated MEQs. An important aspect of the analysis is the concept of a rock mass that is critically stressed for shear failure. This means that shear stress in the region is near the rock-mass frictional strength, and therefore very small perturbations of the stress field can trigger an MEQ. Our analysis shows that the most important cause for injection-induced MEQs at The Geysers is cooling and associated thermal-elastic shrinkage of the rock around the injected fluid that changes the stress state in such a way that mechanical failure and seismicity can be induced. Specifically, the cooling shrinkage results in unloading and associated loss of shear strength in critically shear-stressed fractures, which are then reactivated. Thus, our analysis shows that cooling-induced shear slip along fractures is the dominant mechanism of injection-induced MEQs at The Geysers.

  12. Split ring containment attachment device

    DOE Patents [OSTI]

    Sammel, Alfred G.

    1996-01-01

    A containment attachment device 10 for operatively connecting a glovebag 200 to plastic sheeting 100 covering hazardous material. The device 10 includes an inner split ring member 20 connected on one end 22 to a middle ring member 30 wherein the free end 21 of the split ring member 20 is inserted through a slit 101 in the plastic sheeting 100 to captively engage a generally circular portion of the plastic sheeting 100. A collar potion 41 having an outer ring portion 42 is provided with fastening means 51 for securing the device 10 together wherein the glovebag 200 is operatively connected to the collar portion 41.

  13. Cool covered sky-splitting spectrum-splitting FK

    SciTech Connect (OSTI)

    Mohedano, Rubén; Chaves, Julio; Falicoff, Waqidi; Hernandez, Maikel; Sorgato, Simone; Miñano, Juan C.; Benitez, Pablo; Buljan, Marina

    2014-09-26

    Placing a plane mirror between the primary lens and the receiver in a Fresnel Köhler (FK) concentrator gives birth to a quite different CPV system where all the high-tech components sit on a common plane, that of the primary lens panels. The idea enables not only a thinner device (a half of the original) but also a low cost 1-step manufacturing process for the optics, automatic alignment of primary and secondary lenses, and cell/wiring protection. The concept is also compatible with two different techniques to increase the module efficiency: spectrum splitting between a 3J and a BPC Silicon cell for better usage of Direct Normal Irradiance DNI, and sky splitting to harvest the energy of the diffuse radiation and higher energy production throughout the year. Simple calculations forecast the module would convert 45% of the DNI into electricity.

  14. Hydrogen Production: Photoelectrochemical Water Splitting | Department of

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

    Energy Photoelectrochemical Water Splitting Hydrogen Production: Photoelectrochemical Water Splitting In photoelectrochemical (PEC) water splitting, hydrogen is produced from water using sunlight and specialized semiconductors called photoelectrochemical materials, which use light energy to directly dissociate water molecules into hydrogen and oxygen. This is a long-term technology pathway, with the potential for low or no greenhouse gas emissions. How Does it Work? The PEC water splitting

  15. EA-225 Split Rock Energy LLC | Department of Energy

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

    5 Split Rock Energy LLC EA-225 Split Rock Energy LLC Order authorizing Split Rock Energy LLC to export electric energy to Canada. PDF icon EA-225 Split Rock Energy LLC

  16. Algebraic techniques for diagonalization of a split quaternion matrix in split quaternionic mechanics

    SciTech Connect (OSTI)

    Jiang, Tongsong; Jiang, Ziwu; Zhang, Zhaozhong

    2015-08-15

    In the study of the relation between complexified classical and non-Hermitian quantum mechanics, physicists found that there are links to quaternionic and split quaternionic mechanics, and this leads to the possibility of employing algebraic techniques of split quaternions to tackle some problems in complexified classical and quantum mechanics. This paper, by means of real representation of a split quaternion matrix, studies the problem of diagonalization of a split quaternion matrix and gives algebraic techniques for diagonalization of split quaternion matrices in split quaternionic mechanics.

  17. Ductless Mini-Split Air Conditioners

    Broader source: Energy.gov [DOE]

    Ductless mini-split air conditioners are a good choice if you want a zoned air conditioning system but have no ducts in your house.

  18. Splitting the Cycle the Right Way

    Broader source: Energy.gov [DOE]

    The unique opposed-cylinder configuration of the TourEngine allows superior thermal management and efficient gas transfer compared to other split-cycle designs.

  19. Minimal Doubling and Point Splitting

    SciTech Connect (OSTI)

    Creutz, M.

    2010-06-14

    Minimally-doubled chiral fermions have the unusual property of a single local field creating two fermionic species. Spreading the field over hypercubes allows construction of combinations that isolate specific modes. Combining these fields into bilinears produces meson fields of specific quantum numbers. Minimally-doubled fermion actions present the possibility of fast simulations while maintaining one exact chiral symmetry. They do, however, introduce some peculiar aspects. An explicit breaking of hyper-cubic symmetry allows additional counter-terms to appear in the renormalization. While a single field creates two different species, spreading this field over nearby sites allows isolation of specific states and the construction of physical meson operators. Finally, lattice artifacts break isospin and give two of the three pseudoscalar mesons an additional contribution to their mass. Depending on the sign of this mass splitting, one can either have a traditional Goldstone pseudoscalar meson or a parity breaking Aoki-like phase.

  20. Ductless, Mini-Split Heat Pump Basics

    Broader source: Energy.gov [DOE]

    Ductless, mini-split-system heat pumps (mini splits), as their name implies, do not have ducts. Therefore, they make good retrofit add-ons to houses or buildings with "non-ducted" heating systems, such as hydronic (hot water heat), radiant panels, and space heaters (wood, kerosene, propane).

  1. Precision aligned split V-block

    DOE Patents [OSTI]

    George, Irwin S.

    1984-01-01

    A precision aligned split V-block for holding a workpiece during a milling operation having an expandable frame for allowing various sized workpieces to be accommodated, is easily secured directly to the mill table and having key lugs in one base of the split V-block that assures constant alignment.

  2. Innovative solar thermochemical water splitting.

    SciTech Connect (OSTI)

    Hogan, Roy E. Jr.; Siegel, Nathan P.; Evans, Lindsey R.; Moss, Timothy A.; Stuecker, John Nicholas; Diver, Richard B., Jr.; Miller, James Edward; Allendorf, Mark D.; James, Darryl L.

    2008-02-01

    Sandia National Laboratories (SNL) is evaluating the potential of an innovative approach for splitting water into hydrogen and oxygen using two-step thermochemical cycles. Thermochemical cycles are heat engines that utilize high-temperature heat to produce chemical work. Like their mechanical work-producing counterparts, their efficiency depends on operating temperature and on the irreversibility of their internal processes. With this in mind, we have invented innovative design concepts for two-step solar-driven thermochemical heat engines based on iron oxide and iron oxide mixed with other metal oxides (ferrites). The design concepts utilize two sets of moving beds of ferrite reactant material in close proximity and moving in opposite directions to overcome a major impediment to achieving high efficiency--thermal recuperation between solids in efficient counter-current arrangements. They also provide inherent separation of the product hydrogen and oxygen and are an excellent match with high-concentration solar flux. However, they also impose unique requirements on the ferrite reactants and materials of construction as well as an understanding of the chemical and cycle thermodynamics. In this report the Counter-Rotating-Ring Receiver/Reactor/Recuperator (CR5) solar thermochemical heat engine and its basic operating principals are described. Preliminary thermal efficiency estimates are presented and discussed. Our ferrite reactant material development activities, thermodynamic studies, test results, and prototype hardware development are also presented.

  3. Quantum chaos in systems with ray splitting

    SciTech Connect (OSTI)

    Couchman, L. (Acoustics Division, Naval Research Laboratory, Washington, D.C. 20375 (United States)); Ott, E.; Antonsen, T.M. Jr. (Laboratory for Plasma Research, Department of Electrical Engineering, Department of Physics, University of Maryland, College Park, Maryland 20742 (United States))

    1992-11-15

    We consider wave systems in which rays split on reflection from sharp boundaries. Examples include the Schroedinger equation with the potential changing discontinuously across a surface, electromagnetic waves in a region with a discontinuous dielectric constant, elastic media with a clamped or free boundary, etc. By introducing a Monte Carlo treatment of the rays, it is possible to define chaotic rays via the standard Lyapunov number criterion. Numerical implementation of the Monte Carlo ray technique is carried out for the example of elastic media, and is utilized to investigate the extent to which these systems are globally ergodic. It is suggested that results from previous extensive work on quantum chaos without ray splitting can be extended to these ray splitting problems. In particular, we indicate a generalization of the Gutzwiller trace formula to cover ray splitting.

  4. Strategies to Address Split Incentives in Multifamily Buildings...

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

    Strategies to Address Split Incentives in Multifamily Buildings Better Buildings Neighborhood Program Multifamily Low-Income Peer Exchange Call: Strategies to Address Split ...

  5. Strategies to Overcome Split Incentive Tenant / Landlord Issues...

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

    Strategies to Overcome Split Incentive Tenant Landlord Issues Better Buildings Residential Network Multifamily and Low-Income Peer Exchange Call: Strategies to Overcome Split ...

  6. Two Electron Holes in Hematite Facilitate Water Splitting

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

    Two Electron Holes in Hematite Facilitate Water Splitting Two Electron Holes in Hematite Facilitate Water Splitting Print Wednesday, 26 September 2012 00:00 Hydrogen is an...

  7. Extremely stable bare hematite photoanode for solar water splitting...

    Office of Scientific and Technical Information (OSTI)

    Extremely stable bare hematite photoanode for solar water splitting Prev Next Title: Extremely stable bare hematite photoanode for solar water splitting Authors: Dias, Paula ; ...

  8. Two Electron Holes in Hematite Facilitate Water Splitting

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

    A molecular glance at water splitting. Hematite could play an important role in the generation of hydrogen by solar-powered water splitting, resulting in a truly...

  9. Excitonic exchange splitting in bulk semiconductors

    SciTech Connect (OSTI)

    Fu, H.; Wang, L.; Zunger, A.

    1999-02-01

    We present an approach to calculate the excitonic fine-structure splittings due to electron-hole short-range exchange interactions using the local-density approximation pseudopotential method, and apply it to bulk semiconductors CdSe, InP, GaAs, and InAs. Comparing with previous theoretical results, the current calculated splittings agree well with experiments. Furthermore, we provide an approximate relationship between the short-range exchange splitting and the exciton Bohr radius, which can be used to estimate the exchange splitting for other materials. The current calculation indicates that a commonly used formula for exchange splitting in quantum dot is not valid. Finally, we find a very large pressure dependence of the exchange splitting: a factor of 4.5 increase as the lattice constant changes by 3.5{percent}. This increase is mainly due to the decrease of the Bohr radius via the change of electron effective mass. {copyright} {ital 1999} {ital The American Physical Society}

  10. Shear wave transducer for stress measurements in boreholes

    DOE Patents [OSTI]

    Mao, Nai-Hsien

    1987-01-01

    A technique and apparatus for estimating in situ stresses by measuring stress-induced velocity anisotropy around a borehole. Two sets each of radially and tangentially polarized transducers are placed inside the hole with displacement directions either parallel or perpendicular to the principal stress directions. With this configuration, relative travel times are measured by both a pulsed phase-locked loop technique and a cross correlation of digitized waveforms. The biaxial velocity data is used to back-calculate the applied stress.

  11. Ductless Mini-Split Air Conditioners | Department of Energy

    Office of Environmental Management (EM)

    Mini-Split Air Conditioners A ductless mini-split air conditioner is one solution to cooling part of a house. | Photo courtesy of iStockphotoLUke1138. A ductless...

  12. Ductless, Mini-Split Heat Pumps | Department of Energy

    Energy Savers [EERE]

    Heat Pump Systems Ductless, Mini-Split Heat Pumps Ductless, Mini-Split Heat Pumps ... Learn More Heat pump systems Air-source heat pumps Geothermal heat pumps Absorption heat ...

  13. Ductless, Mini-Split Heat Pumps | Department of Energy

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

    remodel and your home does not have heating and cooling ducts, a ductless mini-split heat pump may be a cost-effective, energy-efficient choice. Ductless, mini-split-system heat...

  14. Two Electron Holes in Hematite Facilitate Water Splitting

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

    Two Electron Holes in Hematite Facilitate Water Splitting Two Electron Holes in Hematite Facilitate Water Splitting Print Wednesday, 26 September 2012 00:00 Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long

  15. TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES...

    Open Energy Info (EERE)

    COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING. Proceedings of () ; () : PROCEEDINGS, Twenty-Seventh Workshop on Geothermal Reservoir Engineering Stanford...

  16. Splitting of the Pygmy Dipole Resonance

    SciTech Connect (OSTI)

    Endres, J.; Zilges, A.; Butler, P.; Herzberg, R.-D.; Scheck, M.; Harakeh, M. N.; Harissopulos, S.; Lagoyannis, A.; Kruecken, R.; Ring, P.; Litvinova, E.; Pietralla, N.; Ponomarev, V. Yu.; Sonnabend, K.; Popescu, L.; Savran, D.; Stoica, V. I.; Woertche, H. J.

    2011-10-28

    In recent years investigations have been made to study the electric Pygmy Dipole Resonance (PDR) systematically, mainly in semi-magic nuclei. For this purpose the well understood high resolution ({gamma},{gamma}') photon scattering method is used. In complementary ({alpha},{alpha}'{gamma}) coincidence experiments at E{sub {alpha}} = 136 MeV a similar {gamma}-energy resolution and a high selectivity to E1 transitions can be obtained at the Big-Bite Spectrometer (BBS) at KVI, Groningen. In comparison to the ({gamma},{gamma}') method a structural splitting of the PDR is observed in the N = 82 nuclei {sup 138}Ba and {sup 140}Ce and in the Z = 50 nucleus {sup 124}Sn. The low energy part is excited in ({gamma},{gamma}') as well as in ({alpha},{alpha}'{gamma}) while the high energy part is observed in ({gamma},{gamma}') only. The experimental results together with theoretical QPM and RQTBA calculations on {sup 124}Sn which are able to reproduce the splitting of the PDR qualitatively are presented. The low-lying group of J{sup {pi}} = 1{sup -} states seem to represent the more isoscalar neutron-skin oscillation of the PDR while the energetically higher-lying states seemingly belong to the transitional region between the PDR and the isovector Giant Dipole Resonance (IVGDR).

  17. Split Venturi, Axially-Rotated Valve

    DOE Patents [OSTI]

    Walrath, David E.; Lindberg, William R.; Burgess, Robert K.

    2000-08-29

    The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane.

  18. Flow Split Venturi, Axially-Rotated Valve

    DOE Patents [OSTI]

    Walrath, David E.; Lindberg, William R.; Burgess, Robert K.; LaBelle, James

    2000-02-22

    The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. An axially aligned outlet may also increase the flow efficiency. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane. A seal separator may increase the useful life of the seal between the fixed and rotatable portions.

  19. Two Electron Holes in Hematite Facilitate Water Splitting

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

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  20. Two Electron Holes in Hematite Facilitate Water Splitting

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

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  1. Two Electron Holes in Hematite Facilitate Water Splitting

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

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  2. Two Electron Holes in Hematite Facilitate Water Splitting

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

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  3. Two Electron Holes in Hematite Facilitate Water Splitting

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

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  4. Enforcement Policy: Split-System Central Air Conditioners Without HSVC |

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

    Department of Energy Split-System Central Air Conditioners Without HSVC Enforcement Policy: Split-System Central Air Conditioners Without HSVC December 16, 2015 DOE issued an enforcement policy that it would begin investigating the methods manufacturers are using to rate split-system central air conditioners that do not have a highest sales volume combination (HSVC) to test as required by the applicable regulations and that it would assess penalties for units manufactured after February 1,

  5. Advanced Water Splitting Materials Workshop | Department of Energy

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

    Water Splitting Materials Workshop Advanced Water Splitting Materials Workshop The U.S. Department of Energy's (DOE's) Lawrence Berkeley National Laboratory and Stanford University held the Advanced Water Splitting Materials Workshop on April 14-15, 2016, in Stanford, California. The workshop was supported by the DOE Fuel Cell Technologies Office and its purpose was to gather stakeholder input that will be foundational to the establishment of the DOE's Energy Materials Network (EMN) consortium

  6. Strategies to Address Split Incentives in Multifamily Buildings |

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

    Department of Energy to Address Split Incentives in Multifamily Buildings Strategies to Address Split Incentives in Multifamily Buildings Better Buildings Neighborhood Program Multifamily / Low-Income Peer Exchange Call: Strategies to Address Split Incentives in Multifamily Buildings, Call Slides and Discussion Summary, April 26, 2012. PDF icon Call Slides and Discussion Summary More Documents & Publications Outreach to Multifamily Landlords and Tenants Stewards of Affordable Housing for

  7. Fast, Efficient Isothermal Redox to Split Water or Carbon Dioxide...

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

    Fast, Efficient Isothermal Redox to Split Water or Carbon Dioxide using Solar Energy ... the hercynite cycle allows faster, more efficient cycling and less wear on the equipment ...

  8. Ductless, Mini-Split Heat Pumps | Department of Energy

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

    Heat Pump Systems » Ductless, Mini-Split Heat Pumps Ductless, Mini-Split Heat Pumps Ductless, mini-split-system heat pumps (mini splits) make good retrofit add-ons to houses with "non-ducted" heating systems, such as hydronic (hot water heat), radiant panels, and space heaters (wood, kerosene, propane). They can also be a good choice for room additions where extending or installing distribution ductwork is not feasible, and very efficient new homes that require only a small space

  9. Two Electron Holes in Hematite Facilitate Water Splitting

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

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem,...

  10. Learning How Nature Uses Sunlight to Split Water

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

    Highlight LBNL Press Release Physical Biosciences, LBNL 30 November 2006 Learning How Nature Splits Water (Condensed by Brad Plummer from a press release issued by Lawrence...

  11. San Andreas Split Geothermal Region | Open Energy Information

    Open Energy Info (EERE)

    ENERGYGeothermal Home San Andreas Split Geothermal Region Details Areas (0) Power Plants (0) Projects (0) Techniques (0) Assessment of Moderate- and High-Temperature...

  12. Two Electron Holes in Hematite Facilitate Water Splitting

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

    been suspected that in hematite, two different holes are formed with different water-splitting power. The existence of different types of holes with disparate reactivity...

  13. Distributed Reforming of Renewable Liquids via Water Splitting...

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

    Transport Membrane (OTM) (Presentation) Distributed Reforming of Renewable Liquids via Water Splitting using Oxygen Transport Membrane (OTM) (Presentation) Presented at the 2007 ...

  14. Designing spectrum-splitting dichroic filters to optimize current...

    Office of Scientific and Technical Information (OSTI)

    Title: Designing spectrum-splitting dichroic filters to optimize current-matched photovoltaics Authors: Miles, Alexander ; Cocilovo, Byron ; Wheelwright, Brian ; Pan, Wei ; Tweet, ...

  15. Strategies to Overcome Split Incentive Tenant / Landlord Issues

    Broader source: Energy.gov [DOE]

    Better Buildings Residential Network Multifamily and Low-Income Peer Exchange Call: Strategies to Overcome Split Incentive Tenant / Landlord Issues, call slides and discussion summary, September 25, 2014.

  16. Enforcement Policy Statement: Split-System Central Air Conditioners...

    Energy Savers [EERE]

    Split-System Central Air Conditioners Without HSVC December 16, 2015 In the November 9, 2015 central air conditioner test procedure supplemental notice of proposed rulemaking (80 ...

  17. DOE's Gasoline/Diesel PM Split Study | Department of Energy

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

    3 DEER Conference Presentation: Desert Research Institute PDF icon 2003deerfujita.pdf More Documents & Publications DOE's GasolineDiesel PM Split Study DOE's GasolineDiesel PM ...

  18. Split driveshaft pump for hazardous fluids

    DOE Patents [OSTI]

    Evans, II, Thomas P.; Purohit, Jwalit J.; Fazio, John M.

    1995-01-01

    A pump having a split driveshaft for use in pumping hazardous fluids wherein only one driveshaft becomes contaminated by the fluid while the second remains isolated from the fluid. The pump has a first portion and a second portion. The first portion contains a pump motor, the first driveshaft, a support pedestal, and vapor barriers and seals. The second portion contains a second, self-lubricating driveshaft and an impeller. The first and second driveshafts are connected together by a releasable coupling. A shield and a slinger deployed below the coupling prevent fluid from the second portion from reaching the first portion. In operation, only the second assembly comes into contact with the fluid being pumped, so the risk of contamination of the first portion by the hazardous fluid is reduced. The first assembly can be removed for repairs or routine maintenance by decoupling the first and second driveshafts and disconnecting the motor from the casing.

  19. Split-field pupil plane determination apparatus

    DOE Patents [OSTI]

    Salmon, Joseph T. (Livermore, CA)

    1996-01-01

    A split-field pupil plane determination apparatus (10) having a wedge assembly (16) with a first glass wedge (18) and a second glass wedge (20) positioned to divide a laser beam (12) into a first laser beam half (22) and a second laser beam half (24) which diverge away from the wedge assembly (16). A wire mask (26) is positioned immediately after the wedge assembly (16) in the path of the laser beam halves (22, 24) such that a shadow thereof is cast as a first shadow half (30) and a second shadow half (32) at the input to a relay telescope (14). The relay telescope (14) causes the laser beam halves (22, 24) to converge such that the first shadow half (30) of the wire mask (26) is aligned with the second shadow half (32) at any subsequent pupil plane (34).

  20. DOE's Gasoline/Diesel PM Split Study | Department of Energy

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

    4 Diesel Engine Emissions Reduction (DEER) Conference Presentation: National Renewable Energy Laboratory PDF icon 2004_deer_lawson.pdf More Documents & Publications DOE's Gasoline/Diesel PM Split Study DOE's Gasoline/Diesel PM Split Study Collaborative Lubricating Oil Study on Emissions (CLOSE) Project

  1. Open-split interface for mass spectrometers

    DOE Patents [OSTI]

    Diehl, John W.

    1991-01-01

    An open-split interface includes a connector body having four leg members projecting therefrom within a single plane, the first and third legs being coaxial and the second and fourth legs being coaxial. A tubular aperture extends through the first and third legs and a second tubular aperture extends through the second and fourth legs, connecting at a juncture within the center of the connector body. A fifth leg projects from the connector body and has a third tubular aperture extending therethrough to the juncture of the first and second tubular apertures. A capillary column extends from a gas chromatograph into the third leg with its end adjacent the juncture. A flow restrictor tube extends from a mass spectrometer through the first tubular aperture in the first and third legs and into the capillary columnm end, so as to project beyond the end of the third leg within the capillary column. An annular gap between the tube and column allows excess effluent to pass to the juncture. A pair of short capillary columns extend from separate detectors into the second tubular aperture in the second and fourth legs, and are oriented with their ends spaced slightly from the first capillary column end. A sweep flow tube is mounted in the fifth leg so as to supply a helium sweep flow to the juncture.

  2. Fossil analysis pushes back human split from other primates by...

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

    Fossil analysis pushes back human split from other primates by two million years C. ... "Our new research supports early divergence: 10 million years ago for the human-gorilla ...

  3. Two Electron Holes in Hematite Facilitate Water Splitting

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

    by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional...

  4. Building America Case Study: Supplemental Ductless Mini-Split...

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

    Supplemental Ductless Mini-Split Heat Pump in the Hot-Humid Climate Brevard and Volusia ... Average home living area: 1,872 ft 2 Central HVAC heating: Heat pump (2); resistance heat ...

  5. Mini-Split Heat Pumps Multifamily Retrofit Feasibility Study

    SciTech Connect (OSTI)

    Dentz, Jordan; Podorson, David; Varshney, Kapil

    2014-05-01

    Mini-split heat pumps can provide space heating and cooling in many climates and are relatively affordable. These and other features make them potentially suitable for retrofitting into multifamily buildings in cold climates to replace electric resistance heating or other outmoded heating systems. This report investigates the suitability of mini-split heat pumps for multifamily retrofits. Various technical and regulatory barriers are discussed and modeling was performed to compare long-term costs of substituting mini-splits for a variety of other heating and cooling options. A number of utility programs have retrofit mini-splits in both single family and multifamily residences. Two such multifamily programs are discussed in detail.

  6. Field Monitoring Protocol: Mini-Split Heat Pumps

    SciTech Connect (OSTI)

    Dane Christensen; Xia Fang; Jeff Tomerlin; Jon Winkler

    2011-03-01

    This Building America program report provides a detailed method for accurately measuring and monitoring performance of a residential mini-split heat pump, which will be used in high-performance retrofit applications.

  7. Field Monitoring Protocol: Mini-Split Heat Pumps

    SciTech Connect (OSTI)

    Christensen, D.; Fang, X.; Tomerlin, J.; Winkler, J.; Hancock, E.

    2011-03-01

    The report provides a detailed method for accurately measuring and monitoring performance of a residential Mini-Split Heat Pump. It will be used in high-performance retrofit applications, and as part of DOE's Building America residential research program.

  8. Splitting a C-O bond in dialkylethers with

    Office of Scientific and Technical Information (OSTI)

    bis(1,2,4-tri-t-butylcyclopentadienyl) cerium-hydride does not occur by a sigma-bond metathesis pathway: a combined experimental and DFT computational study (Journal Article) | SciTech Connect Splitting a C-O bond in dialkylethers with bis(1,2,4-tri-t-butylcyclopentadienyl) cerium-hydride does not occur by a sigma-bond metathesis pathway: a combined experimental and DFT computational study Citation Details In-Document Search Title: Splitting a C-O bond in dialkylethers with

  9. Split-System Cold Climate Heat Pump | Department of Energy

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

    Split-System Cold Climate Heat Pump Split-System Cold Climate Heat Pump Photo of the prototype cold climate heat pump outdoor unit, installed at the Ohio field test site in January 2015. <br />Credit: Oak Ridge National Laboratory Photo of the prototype cold climate heat pump outdoor unit, installed at the Ohio field test site in January 2015. Credit: Oak Ridge National Laboratory Lead Performer: Oak Ridge National Laboratory - Oak Ridge, TN Partners: -- Unico Inc. - St. Louis, MO --

  10. Ductless Mini-Split Heat Pump Comfort Evaluation

    SciTech Connect (OSTI)

    Roth, K.; Sehgal, N.; Akers, C.

    2013-03-01

    Field tests were conducted in two homes in Austin, TX to evaluate the comfort performance of ductless mini-split heat pumps (DMSHPs), measuring temperature and relative humidity measurements in four rooms in each home before and after retrofitting a central HVAC system with DMSHPs.

  11. Optimization of the main parameters of miniature split Stirling cooler

    SciTech Connect (OSTI)

    Tsesarsky, J.

    1995-12-01

    Unlike other modern industrial products Stirling refrigerators development is based mainly on experimental methods. Newly developed high accuracy numerical model for Stirling refrigerators analysis provides good approximation of gas stream process assured by large number of nodes placed in regenerator (300) and large number of time steps (240 per one machine turn). Confidence in accuracy of equations solution makes possible Stirling coolers optimization. In addition to information about refrigerator temperature field the model provides information about driving force of split cooler displacer for computer aided design of displacer driver. In this paper, four parameters of split Stirling refrigerator are optimized: compressor-expander swept volume ratio; phase angle; regenerator length; and regenerator diameter. In each program run power delivered to gas was kept constant by continuous correction of compressor and expander strokes without changing their ratio. Collection of the results produce the optimum cooler structure. Driving displacer force-theta function is also available.

  12. Protein subcellular localization assays using split fluorescent proteins

    DOE Patents [OSTI]

    Waldo, Geoffrey S.; Cabantous, Stephanie

    2009-09-08

    The invention provides protein subcellular localization assays using split fluorescent protein systems. The assays are conducted in living cells, do not require fixation and washing steps inherent in existing immunostaining and related techniques, and permit rapid, non-invasive, direct visualization of protein localization in living cells. The split fluorescent protein systems used in the practice of the invention generally comprise two or more self-complementing fragments of a fluorescent protein, such as GFP, wherein one or more of the fragments correspond to one or more beta-strand microdomains and are used to "tag" proteins of interest, and a complementary "assay" fragment of the fluorescent protein. Either or both of the fragments may be functionalized with a subcellular targeting sequence enabling it to be expressed in or directed to a particular subcellular compartment (i.e., the nucleus).

  13. Towards a Design of a Complete Solar Water Splitting System

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

    Towards a Design of a Complete Solar Water Splitting System 1 Feb 2013 BISfuel© : A team of Bisfuel researchers led by Devens Gust, Ana Moore and Tom Moore has designed and characterized an artificial photosynthetic reaction center inspired by natural Photosystem II and comprising a highly oxidizing porphyrin linked to a biomimetic electron transfer relay and a porphyrin electron acceptor. Two articles with the results of the study have appeared in September special issue of PNAS "Chemical

  14. Permanent split capacitor single phase electric motor system

    DOE Patents [OSTI]

    Kirschbaum, Herbert S.

    1984-01-01

    A permanent split capacitor single phase electric motor achieves balanced operation at more than one operating point by adjusting the voltage supplied to the main and auxiliary windings and adjusting the capacitance in the auxiliary winding circuit. An intermediate voltage tap on an autotransformer supplies voltage to the main winding for low speed operation while a capacitive voltage divider is used to adjust the voltage supplied to the auxiliary winding for low speed operation.

  15. Permanent split capacitor single phase electric motor system

    DOE Patents [OSTI]

    Kirschbaum, H.S.

    1984-08-14

    A permanent split capacitor single phase electric motor achieves balanced operation at more than one operating point by adjusting the voltage supplied to the main and auxiliary windings and adjusting the capacitance in the auxiliary winding circuit. An intermediate voltage tap on an autotransformer supplies voltage to the main winding for low speed operation while a capacitive voltage divider is used to adjust the voltage supplied to the auxiliary winding for low speed operation. 4 figs.

  16. Field Monitoring Protocol: Mini-Split Heat Pumps

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

    Prepared by the National Renewable Energy Laboratory For the U.S. Department of Energy Building Technologies Program Field Monitoring Protocol: Mini-Split Heat Pumps D. Christensen, X. Fang, J. Tomerlin, and J. Winkler National Renewable Energy Laboratory E. Hancock Mountain Energy Partnership March 2011 ii NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their

  17. Nanoscale Strontium Titanate Photocatalysts for Overall Water Splitting

    SciTech Connect (OSTI)

    Townsend, Troy K.; Browning, Nigel D.; Osterloh, Frank

    2012-08-28

    SrTiO3 (STO) is a large band gap (3.2 eV) semiconductor that catalyzes the overall water splitting reaction under UV light irradiation in the presence of a NiO cocatalyst. As we show here, the reactivity persists in nanoscale particles of the material, although the process is less effective at the nanoscale. To reach these conclusions, Bulk STO, 30 5 nm STO, and 6.5 1 nm STO were synthesized by three different methods, their crystal structures verified with XRD and their morphology observed with HRTEM before and after NiO deposition. In connection with NiO, all samples split water into stoichiometric mixtures of H2 and O2, but the activity is decreasing from 28 ?mol H2 g1 h1 (bulk STO), to 19.4 ?mol H2 g1 h1 (30 nm STO), and 3.0 ?mol H2 g1 h1 (6.5 nm STO). The reasons for this decrease are an increase of the water oxidation overpotential for the smaller particles and reduced light absorption due to a quantum size effect. Overall, these findings establish the first nanoscale titanate photocatalyst for overall water splitting.

  18. Rational design of a split-Cas9 enzyme complex

    SciTech Connect (OSTI)

    Wright, Addison V.; Sternberg, Samuel H.; Taylor, David W.; Staahl, Brett T.; Bardales, Jorge A.; Kornfeld, Jack E.; Doudna, Jennifer A.

    2015-02-23

    Cas9, an RNA-guided DNA endonuclease found in clustered regularly interspaced short palindromic repeats (CRISPR) bacterial immune systems, is a versatile tool for genome editing, transcriptional regulation, and cellular imaging applications. Structures of Streptococcus pyogenes Cas9 alone or bound to single-guide RNA (sgRNA) and target DNA revealed a bilobed protein architecture that undergoes major conformational changes upon guide RNA and DNA binding. To investigate the molecular determinants and relevance of the interlobe rearrangement for target recognition and cleavage, we designed a split-Cas9 enzyme in which the nuclease lobe and ?-helical lobe are expressed as separate polypeptides. The lobes do not interact on their own, the sgRNA recruits them into a ternary complex that recapitulates the activity of full-length Cas9 and catalyzes site-specific DNA cleavage. The use of a modified sgRNA abrogates split-Cas9 activity by preventing dimerization, allowing for the development of an inducible dimerization system. We propose that split-Cas9 can act as a highly regulatable platform for genome-engineering applications.

  19. Rational design of a split-Cas9 enzyme complex

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

    Wright, Addison V.; Sternberg, Samuel H.; Taylor, David W.; Staahl, Brett T.; Bardales, Jorge A.; Kornfeld, Jack E.; Doudna, Jennifer A.

    2015-02-23

    Cas9, an RNA-guided DNA endonuclease found in clustered regularly interspaced short palindromic repeats (CRISPR) bacterial immune systems, is a versatile tool for genome editing, transcriptional regulation, and cellular imaging applications. Structures of Streptococcus pyogenes Cas9 alone or bound to single-guide RNA (sgRNA) and target DNA revealed a bilobed protein architecture that undergoes major conformational changes upon guide RNA and DNA binding. To investigate the molecular determinants and relevance of the interlobe rearrangement for target recognition and cleavage, we designed a split-Cas9 enzyme in which the nuclease lobe and α-helical lobe are expressed as separate polypeptides. The lobes do not interactmore » on their own, the sgRNA recruits them into a ternary complex that recapitulates the activity of full-length Cas9 and catalyzes site-specific DNA cleavage. The use of a modified sgRNA abrogates split-Cas9 activity by preventing dimerization, allowing for the development of an inducible dimerization system. We propose that split-Cas9 can act as a highly regulatable platform for genome-engineering applications.« less

  20. Systems and methods for displaying data in split dimension levels

    DOE Patents [OSTI]

    Stolte, Chris; Hanrahan, Patrick

    2015-07-28

    Systems and methods for displaying data in split dimension levels are disclosed. In some implementations, a method includes: at a computer, obtaining a dimensional hierarchy associated with a dataset, wherein the dimensional hierarchy includes at least one dimension and a sub-dimension of the at least one dimension; and populating information representing data included in the dataset into a visual table having a first axis and a second axis, wherein the first axis corresponds to the at least one dimension and the second axis corresponds to the sub-dimension of the at least one dimension.

  1. Split ring floating air riding seal for a turbine

    SciTech Connect (OSTI)

    Mills, Jacob A

    2015-11-03

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, and a central passage connecting the annular cavity to the annular piston chamber to supply compressed air to the seal face, where the annular piston assembly is a split piston assembly to maintain a tight seal as coning of the rotor disk occurs.

  2. Microearthquake Technology for EGS Fracture Characterization...

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

    Engineered Geothermal System through Hydraulic and Thermal Stimulation Integration of Noise and Coda Correlation Data into Kinematic and Waveform Inversions Newberry EGS...

  3. Microearthquake Technology for EGS Fracture Characterization

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

    7 | US DOE Geothermal Program eere.energy.gov ScientificTechnical Approach * ... Peak, Nevada - A geothermal field in Indonesia - Long Valley caldera, California - the ...

  4. Micro-Earthquake | Open Energy Information

    Open Energy Info (EERE)

    as well as fluid expansioncompression. Measurement of microseismicity can aid in the management of reinjection during the production of the geothermal field. Levels of...

  5. AN ARECIBO SURVEY FOR ZEEMAN SPLITTING IN OH MEGAMASER GALAXIES

    SciTech Connect (OSTI)

    McBride, James; Heiles, Carl E-mail: heiles@astro.berkeley.edu

    2013-01-20

    We present the results of a comprehensive survey using the Arecibo Observatory for Zeeman splitting of OH lines in OH megamasers (OHMs). A total of 77 sources were observed with the Arecibo telescope. Of these, maser emission could not be detected for eight sources, and two sources were only ambiguously detected. Another 27 sources were detected at low signal-to-noise ratios or with interference that prevented placing any useful limits on the presence of magnetic fields. In 26 sources, it was possible to place upper limits on the magnitude of magnetic fields, typically between 10 and 30 mG. For 14 sources, the Stokes V spectra exhibit features consistent with Zeeman splitting. Eleven of these 14 are new detections, and the remaining three are re-detections of Stokes V detections in Robishaw et al. Among confident new detections, we derive magnetic fields associated with maser regions with magnitudes ranging from 6.1 to 27.6 mG. The distribution of magnetic field strengths suggests the magnetic fields in OH masing clouds in OHMs are larger than those in Galactic OH masers. The results are consistent with magnetic fields playing a dynamically important role in OH masing clouds in OHMs.

  6. Isoscalar and Isovector Splitting of Pygmy Dipole Structures

    SciTech Connect (OSTI)

    Paar, N.; Vretenar, D.; Niu, Y. F.; Meng, J.

    2009-07-17

    The electric-dipole response of {sup 140}Ce is investigated using the fully consistent relativistic quasiparticle random phase approximation. By analyzing the isospin structure of the E1 response, it is shown that the low-energy (pygmy) strength separates into two segments with different isospin character. The more pronounced pygmy structure at lower energy is composed of predominantly isoscalar states with surface-peaked transition densities. At somewhat higher energy the calculated E1 strength is primarily of isovector character, as expected for the low-energy tail of the giant dipole resonance. The results are in qualitative agreement with those obtained in recent (gamma, gamma{sup '}) and (alpha, alpha{sup '}gamma) experiments, and provide a simple explanation for the splitting of low-energy E1 strength into two groups of states with different isospin structure and radial dependence of the corresponding transition densities.

  7. Shear wave experiments at the US site at the Grimsel laboratory

    SciTech Connect (OSTI)

    Majer, E.L.; Peterson, J.E. Jr. ); Bluemling, P.; Sattel, G. )

    1990-07-01

    As part of the United States Department of Energy (USDOE) cooperative project with the National Cooperative for the Storage of Radioactive Waste (Nagra) of Switzerland, there have been a series of studies carried out at the Nagra underground test facility at Grimsel. The Grimsel test facility is several 3.5 meter diameter tunnels excavated with a tunnel boring machine in the southern Swiss Alps. The rock type is granitic, although there is a large variation in the granitic fabric throughout the facility. The work described here was the first phase of a multiyear project to evaluate and develop seismic imaging techniques for fracture detection and characterization for the use in siting underground nuclear waste facilities. Data from a crosshole tomographic survey in the Underground Seismic (US) site at the Nagra Grimsel test facility in Switzerland and successfully reprocessed to enhance the S-wave arrivals. The results indicate that in a saturated granite Vp/Vs ratios approach 2.0 in the fractured rock. These results indicate that S-wave data would be very useful for fracture detection, especially in detecting thinner fractures.

  8. Electro-optic voltage sensor with Multiple Beam Splitting

    DOE Patents [OSTI]

    Woods, Gregory K.; Renak, Todd W.; Crawford, Thomas M.; Davidson, James R.

    2000-01-01

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  9. Electro-optic voltage sensor with beam splitting

    DOE Patents [OSTI]

    Woods, Gregory K.; Renak, Todd W.; Davidson, James R.; Crawford, Thomas M.

    2002-01-01

    The invention is a miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware typically found in the prior art. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  10. New experimental techniques with the split Hopkinson pressure bar

    SciTech Connect (OSTI)

    Frantz, C.E.; Follansbee, P.S.; Wright, W.J.

    1984-01-01

    The split Hopkinson pressure bar or Kolsky bar has provided for many years a technique for performing compression tests at strain rates approaching 10/sup 4/ s/sup -1/. At these strain rates, the small dimensions possible in a compression test specimen give an advantage over a dynamic tensile test by allowing the stress within the specimen to equilibrate within the shortest possible time. The maximum strain rates possible with this technique are limited by stress wave propagation in the elastic pressure bars as well as in the deforming specimen. This subject is reviewed in this paper, and it is emphasized that a slowly rising excitation is preferred to one that rises steeply. Experimental techniques for pulse shaping and a numerical procedure for correcting the raw data for wave dispersion in the pressure bars are presented. For tests at elevated temperature a bar mover apparatus has been developed which effectively brings the cold pressure bars into contact with the specimen, which is heated with a specially designed furnace, shortly before the pressure wave arrives. This procedure has been used successfully in tests at temperatures as high as 1000/sup 0/C.

  11. Splitting a C-O bond in dialkylethers withbis(1,2,4-tri-t-butylcyclop...

    Office of Scientific and Technical Information (OSTI)

    Splitting a C-O bond in dialkylethers with bis(1,2,4-tri-t-butylcyclopentadienyl) ... Citation Details In-Document Search Title: Splitting a C-O bond in dialkylethers with ...

  12. Laboratory Test Report for Fujitsu 12RLS and Mitsubishi FE12NA Mini-Split Heat Pumps

    SciTech Connect (OSTI)

    Winkler, Jon

    2011-09-01

    Mini-split heat pumps are being proposed as a new retrofit option to replace resistance heating in the Pacific Northwest. NREL has previously developed a field test protocol for mini-split systems to ensure consistent results from field tests. This report focuses on the development of detailed system performance maps for mini-split heat pumps so that the potential benefits of mini-split systems can be accurately analyzed for different climate regions and housing types.

  13. Replacing Resistance Heating with Mini-Split Heat Pumps, Sharon, Connecticut (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-05-01

    Mini-split heat pumps can provide space heating and cooling in many climates and are relatively affordable. These and other features make them potentially suitable for retrofitting into multifamily buildings in cold climates to replace electric resistance heating or other outmoded heating systems. This report investigates the suitability of mini-split heat pumps for multifamily retrofits. Various technical and regulatory barriers are discussed and modeling was performed to compare long-term costs of substituting mini-splits for a variety of other heating and cooling options. A number of utility programs have retrofit mini-splits in both single family and multifamily residences. Two such multifamily programs are discussed in detail.

  14. Development of a Solar-Thermal ZnO/Zn Water-Splitting Thermochemical...

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

    Development of a Solar-thermal ZnOZn Water-splitting Thermochemical Cycle Final Report ... Combining this with annual average solar efficiencies, the overall solar to hydrogen LHV ...

  15. Giant and tunable valley degeneracy splitting in MoTe 2 (Journal...

    Office of Scientific and Technical Information (OSTI)

    This content will become publicly available on September 7, 2016 Title: Giant and tunable valley degeneracy splitting in MoTe 2 Authors: Qi, Jingshan ; Li, Xiao ; Niu, Qian ; Feng, ...

  16. TEMPORAL SPECTRAL SHIFT AND POLARIZATION OF A BAND-SPLITTING SOLAR TYPE II RADIO BURST

    SciTech Connect (OSTI)

    Du, Guohui; Chen, Yao; Lv, Maoshui; Kong, Xiangliang; Feng, Shiwei; Guo, Fan; Li, Gang

    2014-10-01

    In many type II solar radio bursts, the fundamental and/or the harmonic branches of the bursts can split into two almost parallel bands with similar spectral shapes and frequency drifts. However, the mechanisms accounting for this intriguing phenomenon remain elusive. In this study, we report a special band-splitting type II event in which spectral features appear systematically earlier on the upper band (with higher frequencies) than on the lower band (with lower frequencies) by several seconds. Furthermore, the emissions carried by the splitting band are moderately polarized with the left-hand polarized signals stronger than the right-hand ones. The polarization degree varies in a range of 0.3 to 0.6. These novel observational findings provide important constraints on the underlying physical mechanisms of band-splitting of type II radio bursts.

  17. Building America Case Study: Long-Term Monitoring of Mini-Split...

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

    Long-Term Monitoring of Mini-Split Ductless Heat Pumps in the Northeast Devens and ... (BSC) evaluated the long-term performance of MSHPs in 8 homes during a period of 3 years. ...

  18. Solar High Temperature Water-Splitting Cycle with Quantum Boost

    SciTech Connect (OSTI)

    Taylor, Robin; Davenport, Roger; Talbot, Jan; Herz, Richard; Genders, David; Symons, Peter; Brown, Lloyd

    2014-04-25

    A sulfur family chemical cycle having ammonia as the working fluid and reagent was developed as a cost-effective and efficient hydrogen production technology based on a solar thermochemical water-splitting cycle. The sulfur ammonia (SA) cycle is a renewable and sustainable process that is unique in that it is an all-fluid cycle (i.e., with no solids handling). It uses a moderate temperature solar plant with the solar receiver operating at 800°C. All electricity needed is generated internally from recovered heat. The plant would operate continuously with low cost storage and it is a good potential solar thermochemical hydrogen production cycle for reaching the DOE cost goals. Two approaches were considered for the hydrogen production step of the SA cycle: (1) photocatalytic, and (2) electrolytic oxidation of ammonium sulfite to ammonium sulfate in aqueous solutions. Also, two sub-cycles were evaluated for the oxygen evolution side of the SA cycle: (1) zinc sulfate/zinc oxide, and (2) potassium sulfate/potassium pyrosulfate. The laboratory testing and optimization of all the process steps for each version of the SA cycle were proven in the laboratory or have been fully demonstrated by others, but further optimization is still possible and needed. The solar configuration evolved to a 50 MW(thermal) central receiver system with a North heliostat field, a cavity receiver, and NaCl molten salt storage to allow continuous operation. The H2A economic model was used to optimize and trade-off SA cycle configurations. Parametric studies of chemical plant performance have indicated process efficiencies of ~20%. Although the current process efficiency is technically acceptable, an increased efficiency is needed if the DOE cost targets are to be reached. There are two interrelated areas in which there is the potential for significant efficiency improvements: electrolysis cell voltage and excessive water vaporization. Methods to significantly reduce water evaporation are proposed for future activities. Electrolysis membranes that permit higher temperatures and lower voltages are attainable. The oxygen half cycle will need further development and improvement.

  19. Spin rotators and split Siberian Snakes (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Spin rotators and split Siberian Snakes Citation Details In-Document Search Title: Spin rotators and split Siberian Snakes The study of spin effects in the collision of polarized high energy beams requires flexible and compact spin rotators to manipulate the beam polarization direction. Design criteria and specific examples are presented for high energy, orbit transparent spin rotators ranging from small angle rotators to be used for the excitation of spin resonances to large angle rotators to

  20. Spin rotators and split Siberian Snakes (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Spin rotators and split Siberian Snakes Citation Details In-Document Search Title: Spin rotators and split Siberian Snakes × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this document is also available for sale to

  1. Particle Splitting for Monte-Carlo Simulation of the National Ignition

    Office of Scientific and Technical Information (OSTI)

    Facility (Conference) | SciTech Connect Particle Splitting for Monte-Carlo Simulation of the National Ignition Facility Citation Details In-Document Search Title: Particle Splitting for Monte-Carlo Simulation of the National Ignition Facility The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is scheduled for completion in 2009. Thereafter, experiments will commence in which capsules of DT will be imploded, generating neutrons, gammas, x-rays, and other

  2. Process and apparatus for split feed of spent catalyst to high efficiency

    Office of Scientific and Technical Information (OSTI)

    catalyst regenerator (Patent) | SciTech Connect Process and apparatus for split feed of spent catalyst to high efficiency catalyst regenerator Citation Details In-Document Search Title: Process and apparatus for split feed of spent catalyst to high efficiency catalyst regenerator This patent describes a fluidized catalytic cracking process for catalytic cracking of a heavy hydrocarbon feed. It comprises hydrocarbons having a boiling point above about 650{degrees} F to lighter products by

  3. Designing spectrum-splitting dichroic filters to optimize current-matched

    Office of Scientific and Technical Information (OSTI)

    photovoltaics (Journal Article) | SciTech Connect Designing spectrum-splitting dichroic filters to optimize current-matched photovoltaics Citation Details In-Document Search This content will become publicly available on March 7, 2017 Title: Designing spectrum-splitting dichroic filters to optimize current-matched photovoltaics Authors: Miles, Alexander ; Cocilovo, Byron ; Wheelwright, Brian ; Pan, Wei ; Tweet, Doug ; Norwood, Robert A. Publication Date: 2016-03-07 OSTI Identifier: 1240309

  4. Quantum-splitting oxide-based phosphors, method of producing, and rules for designing the same

    DOE Patents [OSTI]

    Setlur, Anant Achyut; Comanzo, Holly Ann; Srivastava, Alok Mani

    2003-09-16

    Strontium and strontium calcium aluminates and lanthanum and lanthanum magnesium borates activated with Pr.sup.3+ and Mn.sup.2+ exhibit characteristics of quantum-splitting phosphors. Improved quantum efficiency may be obtained by further doping with Gd.sup.3+. Refined rules for designing quantum-splitting phosphors include the requirement of incorporation of Gd.sup.3+ and Mn.sup.2+ in the host lattice for facilitation of energy migration.

  5. The splitted laser beam filamentation in interaction of laser and an exponential decay inhomogeneous underdense plasma

    SciTech Connect (OSTI)

    Xia Xiongping; Yi Lin; Xu Bin; Lu Jianduo

    2011-10-15

    The splitted beam filamentation in interaction of laser and an exponential decay inhomogeneous underdense plasma is investigated. Based on Wentzel-Kramers-Brillouin (WKB) approximation and paraxial/nonparaxial ray theory, simulation results show that the steady beam width and single beam filamentation along the propagation distance in paraxial case is due to the influence of ponderomotive nonlinearity. In nonparaxial case, the influence of the off-axial of {alpha}{sub 00} and {alpha}{sub 02} (the departure of the beam from the Gaussian nature) and S{sub 02} (the departure from the spherical nature) results in more complicated ponderomotive nonlinearity and changing of the channel density and refractive index, which led to the formation of two/three splitted beam filamentation and the self-distortion of beam width. In addition, influence of several parameters on two/three splitted beam filamentation is discussed.

  6. Spin polarized current from multiply-coupled rings with Zeeman-split quantum dots

    SciTech Connect (OSTI)

    Hedin, Eric R.; Joe, Yong S.

    2014-03-21

    We investigate transmission resonances and conductance properties of multiple, serially connected, direct-contact nanoscale rings using the tight-binding model. Quantum dots (QDs) are embedded in the two arms of each ring, and Zeeman-splitting of the QD energy levels is incorporated into the system Hamiltonian. Transmission bands develop as the number of rings in series increases, with a band-gap which is sensitive to the degree of Zeeman splitting and the initial settings of the QD site energy values. The current vs. voltage characteristics of the system can be modulated between Ohmic and semiconducting as a function of the Zeeman splitting. In addition, spin-polarized current results for selected ranges of the Fermi energy.

  7. Ions confined in spherical dielectric cavities modeled by a splitting field-theory

    SciTech Connect (OSTI)

    Lue, Leo; Linse, Per

    2015-04-14

    The properties of ions confined within spherical dielectric cavities are examined by a splitting field-theory and Monte Carlo simulations. Three types of cavities are considered: one possessing a uniform surface charge density, one with a uniform volume charge density, and one containing mobile ions. In all cases, mobile counterions are present within the dielectric sphere. The splitting theory is based on dividing the electrostatic interaction into long- and short-wavelength contributions and applying different approximations on the two contributions. The splitting theory works well for the case where the dielectric constant of the confining sphere is equal to or less than that of the medium external to the sphere. Nevertheless, by extending the theory with a virial expansion, the predictions are improved. However, when the dielectric constant of the confining sphere is greater than that of the medium outside the sphere, the splitting theory performs poorly, only qualitatively agreeing with the simulation data. In this case, the strong-coupling expansion does not seem to work well, and a modified mean-field theory where the counterions interact directly with only their own image charge gives improved predictions. The splitting theory works best for the system with a uniform surface charge density and worst for the system with a uniform volume charge density. Increasing the number of ions within the sphere, at a fixed radius, tends to increase the ion density near the surface of the sphere and leads to a depletion region in the sphere interior; however, varying the ion number does not lead to any qualitative changes in the performance of the splitting theory.

  8. Building America Case Studies for Existing Homes: Supplemental Ductless Mini-Split Heat Pump in the Hot-Humid Climate

    Broader source: Energy.gov [DOE]

    The Building America Partnership for Improved Residential Construction team that studied the effects of mini-split heat pumps in six central Florida homes.

  9. Defect-engineered GaN:Mg nanowire arrays for overall water splitting under violet light

    SciTech Connect (OSTI)

    Kibria, M. G.; Chowdhury, F. A.; Zhao, S.; Mi, Z.; Trudeau, M. L.; Guo, H.

    2015-03-16

    We report that by engineering the intra-gap defect related energy states in GaN nanowire arrays using Mg dopants, efficient and stable overall neutral water splitting can be achieved under violet light. Overall neutral water splitting on Rh/Cr{sub 2}O{sub 3} co-catalyst decorated Mg doped GaN nanowires is demonstrated with intra-gap excitation up to 450?nm. Through optimized Mg doping, the absorbed photon conversion efficiency of GaN nanowires reaches ?43% at 375450?nm, providing a viable approach to extend the solar absorption of oxide and non-oxide photocatalysts.

  10. Quantum-splitting oxide-based phosphors and method of producing the same

    DOE Patents [OSTI]

    Setlur, Anant Achyut; Srivastava, Alok Mani

    2003-09-02

    Strontium, calcium, strontium calcium, strontium calcium magnesium, calcium magnesium aluminates, and strontium borates activated with Pr.sup.3+ exhibit characteristics of quantum-splitting phosphors under VUV excitation. A large emission peak at about 405 nm under VUV excitation is used conveniently to identify quantum-splitting phosphors. Improvements may be achieved with addition of fluorides or boric acid as a flux during the preparation of the phosphors. It is also possible to predict improvement in quantum efficiency by observing the ratio of emission intensities at about 480 nm and about 610 nm.

  11. High Efficiency Spectrum Splitting Prototype Submodule Using Commercial CPV Cells (Presentation)

    SciTech Connect (OSTI)

    Keevers, M.; Lau, J.; Green, M.; Thomas, I.; Lasich, J.; King, R.; Emery, K.

    2014-11-01

    This presentation summarizes progress on the design, fabrication and testing of a proof-of-concept, prototype spectrum splitting CPV submodule using commercial CPV cells, aimed at demonstrating an independently confirmed efficiency above 40% at STC (1000 W/m2, AM1.5D ASTM G173-03, 25 degrees C).

  12. DOE NSF Partnership to Address Critical Challenges in Hydrogen Production from Solar Water Splitting

    Broader source: Energy.gov [DOE]

    EERE and the National Science Foundation (NSF) announce a funding opportunity in the area of renewable hydrogen technology research and development, specifically addressing discovery and development of advanced materials systems and chemical proceesses for direct photochemical and/or thermochemical water splitting for application in the solar production of hydrogen fuel.

  13. Influence of dense quantum plasmas on fine-structure splitting of Lyman doublets of hydrogenic systems

    SciTech Connect (OSTI)

    De, Madhab Ray, Debasis

    2015-05-15

    Relativistic calculations are performed to study the effects of oscillatory quantum plasma screening on the fine-structure splitting between the components of Lyman-? and ? line doublets of atomic hydrogen and hydrgen-like argon ion within dense quantum plasmas, where the effective two-body (electronnucleus) interaction is modeled by the ShuklaEliasson oscillatory exponential cosine screened-Coulomb potential. The numerical solutions of the radial Dirac equation for the quantum plasma-embedded atomic systems reveal that the oscillatory quantum screening effect suppresses the doublet (energy) splitting substantially and the suppression becomes more prominent at large quantum wave number k{sub q}. In the absence of the oscillatory cosine screening term, much larger amount of suppression is noticed at larger values of k{sub q}, and the corresponding results represent the screening effect of an exponential screened-Coulomb two-body interaction. The Z{sup 4} scaling of the Lyman doublet splitting in low-Z hydrogen isoelectronic series of ions in free space is violated in dense quantum plasma environments. The relativistic data for the doublet splitting in the zero screening (k{sub q}?=?0) case are in very good agreement with the NIST reference data, with slight discrepancies (?0.2%) arising from the neglect of the quantum electrodynamic effects.

  14. Millimeter wave detection via Autler-Townes splitting in rubidium Rydberg atoms

    SciTech Connect (OSTI)

    Gordon, Joshua A. Holloway, Christopher L.; Schwarzkopf, Andrew; Anderson, Dave A.; Miller, Stephanie; Thaicharoen, Nithiwadee; Raithel, Georg

    2014-07-14

    In this paper, we demonstrate the detection of millimeter waves via Autler-Townes splitting in {sup 85}Rb Rydberg atoms. This method may provide an independent, atom-based, SI-traceable method for measuring mm-wave electric fields, which addresses a gap in current calibration techniques in the mm-wave regime. The electric-field amplitude within a rubidium vapor cell in the WR-10 wave guide band is measured for frequencies of 93.71 GHz and 104.77?GHz. Relevant aspects of Autler-Townes splitting originating from a four-level electromagnetically induced transparency scheme are discussed. We measured the E-field generated by an open-ended waveguide using this technique. Experimental results are compared to a full-wave finite element simulation.

  15. Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields

    DOE Patents [OSTI]

    Clark, M. Collins; Coleman, P. Dale; Marder, Barry M.

    1993-01-01

    A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

  16. Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields

    DOE Patents [OSTI]

    Clark, M.C.; Coleman, P.D.; Marder, B.M.

    1993-08-10

    A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

  17. Tuning magnetic splitting of zigzag graphene nanoribbons by edge functionalization with hydroxyl groups

    SciTech Connect (OSTI)

    Zhang, Huizhen; Yang, Haifang; Li, Lin; Fu, Huixia; Ma, Wei; Niu, Chunyao; Sun, Jiatao; Meng, Sheng; Gu, Changzhi

    2015-03-21

    The electronic properties and relative stability of zigzag graphene nanoribbons are studied by varying the percentage of hydroxyl radicals for edge saturation using first principle calculations. The passivated structures of zigzag graphene nanoribbon have spin-polarized ground state with antiferromagnetic exchange coupling across the edge and ferromagnetic coupling along the edges. When the edges are specially passivated by hydroxyl, the potentials of spin exchange interaction across the two edges shift accordingly, resulting into a spin-semiconductor. Varying the concentration of hydroxyl groups can alter the maximum magnetization splitting. When the percentage of asymmetrically adsorbed hydroxyl reaches 50%, the magnetization splitting can reach a value as high as 275 meV due to the asymmetrical potential across the nanoribbon edges. These results would favor spintronic device applications based on zigzag graphene nanoribbons.

  18. A split-electrode for clearing scattered electrons in the RHIC e-lens

    SciTech Connect (OSTI)

    Gu X.; Pikin, A.; Thieberger, P.; Fischer, W.; Hock, J.; Hamdi, K.; Gassner,D.; Luo, Y.; Montag, C.; Okamura, M.

    2012-05-20

    We are designing two electron lenses that will be installed at RHIC IR10 to compensate for the head-on beam-beam effect. To clear accumulated scattered electrons from 100 GeV proton-electron head-on collisions in the e-lens, a clearing split electrode may be constructed. The feasibility of this proposed electrode was demonstrated via the CST Particle Studio and Opera program simulations. By splitting one of the drift tubes in the e-lens and applying {approx} 380 V across the two parts, the scattered electrons can be cleared out within several hundred micro-seconds. At the same time we can restrict the unwanted shift of the primary electron-beam that already passed the 2-m interaction region in e-lens, to less than 15um.

  19. Two for the Price of One: Water and Carbon Dioxide Splitting via a Single

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

    Catalyst | U.S. DOE Office of Science (SC) 2 » Two for the Price of One: Water and Carbon Dioxide Splitting via a Single Catalyst Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding Opportunities Basic Energy Sciences Advisory Committee (BESAC) Community Resources Contact Information Basic Energy Sciences U.S. Department of Energy SC-22/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3081 F: (301)

  20. Semiconductor-based photoelectrochemical water splitting at the limit of very wide depletion region

    SciTech Connect (OSTI)

    Liu, Mingzhao; Lyons, John L.; Yan, Danhua H.; Hybertsen, Mark S.

    2015-11-23

    In semiconductor-based photoelectrochemical (PEC) water splitting, carrier separation and delivery largely relies on the depletion region formed at the semiconductor/water interface. As a Schottky junction device, the trade-off between photon collection and minority carrier delivery remains a persistent obstacle for maximizing the performance of a water splitting photoelectrode. Here, it is demonstrated that the PEC water splitting efficiency for an n-SrTiO3 (n-STO) photoanode is improved very significantly despite its weak indirect band gap optical absorption (α < 10⁴ cm⁻¹), by widening the depletion region through engineering its doping density and profile. Graded doped n-SrTiO3 photoanodes are fabricated with their bulk heavily doped with oxygen vacancies but their surface lightly doped over a tunable depth of a few hundred nanometers, through a simple low temperature re-oxidation technique. The graded doping profile widens the depletion region to over 500 nm, thus leading to very efficient charge carrier separation and high quantum efficiency (>70%) for the weak indirect transition. As a result, this simultaneous optimization of the light absorption, minority carrier (hole) delivery, and majority carrier (electron) transport by means of a graded doping architecture may be useful for other indirect band gap photocatalysts that suffer from a similar problem of weak optical absorption.

  1. Semiconductor-based photoelectrochemical water splitting at the limit of very wide depletion region

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

    Liu, Mingzhao; Lyons, John L.; Yan, Danhua H.; Hybertsen, Mark S.

    2015-11-23

    In semiconductor-based photoelectrochemical (PEC) water splitting, carrier separation and delivery largely relies on the depletion region formed at the semiconductor/water interface. As a Schottky junction device, the trade-off between photon collection and minority carrier delivery remains a persistent obstacle for maximizing the performance of a water splitting photoelectrode. Here, it is demonstrated that the PEC water splitting efficiency for an n-SrTiO3 (n-STO) photoanode is improved very significantly despite its weak indirect band gap optical absorption (α < 10⁴ cm⁻¹), by widening the depletion region through engineering its doping density and profile. Graded doped n-SrTiO3 photoanodes are fabricated with their bulkmore » heavily doped with oxygen vacancies but their surface lightly doped over a tunable depth of a few hundred nanometers, through a simple low temperature re-oxidation technique. The graded doping profile widens the depletion region to over 500 nm, thus leading to very efficient charge carrier separation and high quantum efficiency (>70%) for the weak indirect transition. As a result, this simultaneous optimization of the light absorption, minority carrier (hole) delivery, and majority carrier (electron) transport by means of a graded doping architecture may be useful for other indirect band gap photocatalysts that suffer from a similar problem of weak optical absorption.« less

  2. Spin orbit splitting of the photon induced Fano resonance in an oscillating graphene electrostatic barrier

    SciTech Connect (OSTI)

    Biswas, R.; Sinha, C.

    2014-04-07

    We investigate theoretically the effect of a time dependent oscillating potential on the transport property of the Dirac Fermion through a monolayer graphene electrostatic barrier under the influence of the Rashba spin orbit interaction. The time dependent problem is solved in the frame work of the non-perturbative Floquet approach. It is noted that the dynamic condition of the barrier may be controlled by tuning the Rashba parameter. Introduction of the spin orbit interaction causes splitting of the Fano resonance (FR), a characteristic feature in photon assisted tunneling. The separation between the spin split FR's gives an indirect measure of the fine structure of the quasi-hole bound state inside the barrier. The present findings on the Rashba splitting of the FR and its external control by tuning the oscillating field parameters might have potential for applications in spintronic devices, especially in the spin field effect transistors. The spin polarization of different Floquet sidebands is found to be quite sensitive to the spin-pseudospin interaction.

  3. Lateral Spectrum Splitting Concentrator Photovoltaics: Direct Measurement of Component and Submodule Efficiency

    SciTech Connect (OSTI)

    Xiaoting, W.; Waite, N.; Murcia, P.; Emery, K.; Steiner, M.; Kiamilev, F.; Goossen, K.; Honsberg, C.; Barnett, A.

    2012-03-01

    To achieve high energy conversion efficiency, a solar module architecture called lateral spectrum splitting concentrator photovoltaics (LSSCPV) is being developed. LSSCPV can concentrate available sunlight and laterally split a single beam into bands with different spectra for absorption by different solar cells with band gaps matched to the split spectrum. Test assemblies of a sample LSSCPV architecture were constructed, each of which contains four p-n junctions and two optical pieces. Independent experiments or simulations had been implemented on the components but by using optimal assumptions. In order to examine the actual performances of all the components, which are dependent on each other and the light source, direct outdoor measurements were made. A set of self-consistent efficiency definitions was articulated and a test bed was developed to measure the parameters required by the efficiency calculation. By comparing the component efficiency items derived from the outdoor measurement and the expected values based on independent simulations, the potential opportunities for efficiency improvement are determined. In the outdoor measurement at the University of Delaware, the optical component demonstrated 89.1% efficiency. Additional assemblies were tested at the National Renewable Energy Laboratory. One assembly demonstrated 36.7% submodule efficiency, which compares favorably with the 32.6% previously reported verified submodule efficiency.

  4. Characterizing Fractures in the Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy

    Broader source: Energy.gov [DOE]

    Determine if fracturing could be used to enhance permeability; and whether dilution of existing fluids with injected water would lower corrosivity enough to allow economic production of power.

  5. Characterizing Fractures in Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy

    SciTech Connect (OSTI)

    Aminzadeh, Fred; Sammis, Charles; Sahimi, Mohammad; Okaya, David

    2015-04-30

    The ultimate objective of the project was to develop new methodologies to characterize the northwestern part of The Geysers geothermal reservoir (Sonoma County, California). The goal is to gain a better knowledge of the reservoir porosity, permeability, fracture size, fracture spacing, reservoir discontinuities (leaky barriers) and impermeable boundaries.

  6. In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels

    DOE Patents [OSTI]

    Hall, Maclin S.; Jackson, Theodore G.; Knerr, Christopher

    1998-02-17

    An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web.

  7. In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels

    DOE Patents [OSTI]

    Hall, M.S.; Jackson, T.G.; Knerr, C.

    1998-02-17

    An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web. 37 figs.

  8. Impacts of urban transportation mode split on CO{sub 2} emissions in Jinan, China.

    SciTech Connect (OSTI)

    He, D.; Meng, F.; Wang, M.; He, K.

    2011-04-01

    As the world's largest developing country, China currently is undergoing rapid urbanization and motorization, which will result in far-reaching impacts on energy and the environment. According to estimates, energy use and carbon emissions in the transportation sector will comprise roughly 30% of total emissions by 2030. Since the late 1990s, transportation-related issues such as energy, consumption, and carbon emissions have become a policy focus in China. To date, most research and policies have centered on vehicle technologies that promote vehicle efficiency and reduced emissions. Limited research exists on the control of greenhouse gases through mode shifts in urban transportation - in particular, through the promotion of public transit. The purpose of this study is to establish a methodology to analyze carbon emissions from the urban transportation sector at the Chinese city level. By using Jinan, the capital of China's Shandong Province, as an example, we have developed an analytical model to simulate energy consumption and carbon emissions based on the number of trips, the transportation mode split, and the trip distance. This model has enabled us to assess the impacts of the transportation mode split on energy consumption and carbon emissions. Furthermore, this paper reviews a set of methods for data collection, estimation, and processing for situations where statistical data are scarce in China. This paper also describes the simulation of three transportation system development scenarios. The results of this study illustrate that if no policy intervention is implemented for the transportation mode split (the business-as-usual (BAU) case), then emissions from Chinese urban transportation systems will quadruple by 2030. However, a dense, mixed land-use pattern, as well as transportation policies that encourage public transportation, would result in the elimination of 1.93 million tons of carbon emissions - approximately 50% of the BAU scenario emissions.

  9. Traveling wave device for combining or splitting symmetric and asymmetric waves

    DOE Patents [OSTI]

    Möbius, Arnold; Ives, Robert Lawrence

    2005-07-19

    A traveling wave device for the combining or splitting of symmetric and asymmetric traveling wave energy includes a feed waveguide for traveling wave energy, the feed waveguide having an input port and a launching port, a reflector for coupling wave energy between the feed waveguide and a final waveguide for the collection and transport of wave energy to or from the reflector. The power combiner has a launching port for symmetrical waves which includes a cylindrical section coaxial to the feed waveguide, and a launching port for asymmetric waves which includes a sawtooth rotated about a central axis.

  10. NREL Documents Efficiency of Mini-Split Heat Pumps (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-06-01

    A new report delivers mini-split heat pump (MSHP) performance data for use in whole-building simulation tools. Mini-split heat pumps (MSHPs) are highly efficient refrigerant-based air conditioning and heating systems that permit room-by-room conditioning and control in homes. Because of their size, efficiency, and price, MSHPs are very popular overseas and are gaining market share in energy-efficient home upgrades in the United States. They are a good option for retrofitting older homes that lack ductwork. To evaluate MSHP cost effectiveness and performance in U.S. homes, National Renewable Energy Laboratory (NREL) researchers are studying these systems in the laboratory, simulated buildings, and field test settings. A new NREL report describes an innovative laboratory approach to testing MSHPs and includes experimental performance maps for use in whole-building simulation tools. Most public information on MSHP performance is provided by equipment manufacturers, and is typically limited to performance at a single operating speed for heating and cooling. Mini-split heat pumps use variable speed components that spin up and down to continuously meet the heating or cooling need, significantly improving a system's operating efficiency. Measuring that efficiency in a laboratory is challenging and required new approaches to performance testing. NREL researchers worked with colleagues at Purdue University's Herrick Labs and Ecotope, Inc. to refine and apply this new approach to a suite of MSHP products. Researchers measured the performance of two MSHPs across a variety of operating conditions, which allowed, for the first time, development of accurate building simulation MSHP models. In the laboratory tests, researchers found that both MSHPs achieved manufacturer-reported performance at rating conditions. However, at other temperature and humidity conditions, the heat pumps capacity ranged from 40% above to 54% below the manufacturer-reported values. Knowing how performance varies is critical in order to reasonably estimate annual energy consumption of a MSHP, and to compare MSHPs to other heating and cooling options. Mini-split heat pump efficiency (COP) was seen to significantly exceed rated efficiency at low compressor speeds-a very important effect.

  11. Light-splitting photovoltaic system utilizing two dual-junction solar cells

    SciTech Connect (OSTI)

    Xiong, Kanglin; Yang, Hui; Lu, Shulong; Dong, Jianrong; Zhou, Taofei; Wang, Rongxin; Jiang, Desheng

    2010-12-15

    There are many difficulties limiting the further development of monolithic multi-junction solar cells, such as the growth of lattice-mismatched material and the current matching constraint. As an alternative approach, the light-splitting photovoltaic system is investigated intensively in different aspects, including the energy loss mechanism and the choice of energy bandgaps of solar cells. Based on the investigation, a two-dual junction system has been implemented employing lattice-matched GaInP/GaAs and InGaAsP/InGaAs cells grown epitaxially on GaAs and InP substrates, respectively. (author)

  12. Micro-Earthquake At New York Canyon Geothermal Area (2011) |...

    Open Energy Info (EERE)

    Rock, D.; Peterson, J.; Jarpe, S. (1 January 2011) DOE REAL-TIME SEISMIC MONITORING AT ENHANCED GEOTHERMAL SYSTEM SITES Additional References Retrieved from "http:...

  13. Micro-Earthquake At Desert Peak Geothermal Area (2011) | Open...

    Open Energy Info (EERE)

    Rock, D.; Peterson, J.; Jarpe, S. (1 January 2011) DOE REAL-TIME SEISMIC MONITORING AT ENHANCED GEOTHERMAL SYSTEM SITES Additional References Retrieved from "http:...

  14. Micro-Earthquake At Newberry Caldera Geothermal Area (2011) ...

    Open Energy Info (EERE)

    Rock, D.; Peterson, J.; Jarpe, S. (1 January 2011) DOE REAL-TIME SEISMIC MONITORING AT ENHANCED GEOTHERMAL SYSTEM SITES Additional References Retrieved from "http:...

  15. Micro-Earthquake At Geysers Geothermal Area (2011) | Open Energy...

    Open Energy Info (EERE)

    Rock, D.; Peterson, J.; Jarpe, S. (1 January 2011) DOE REAL-TIME SEISMIC MONITORING AT ENHANCED GEOTHERMAL SYSTEM SITES Additional References Retrieved from "http:...

  16. Micro-Earthquake At Coso Geothermal Area (1974) | Open Energy...

    Open Energy Info (EERE)

    as many as 100 or more distinct local events; more than two thousand events with S-P times of less than three seconds were detected; observed low value for Poisson's ratio which...

  17. Micro-Earthquake At Coso Geothermal Area (1987) | Open Energy...

    Open Energy Info (EERE)

    variations in the Coso region, California, derived from local earthquake travel times Additional References Retrieved from "http:en.openei.orgwindex.php?titleMicro-Ear...

  18. Multiple Ruptures For Long Valley Microearthquakes- A Link To...

    Open Energy Info (EERE)

    located and analyzed as a function of azimuth, offset, and source characteristics. Eight prime examples lie within two, 7 km-deep clusters of seismicity separated by about 1 km,...

  19. Micro-Earthquake At Roosevelt Hot Springs Geothermal Area (Faulder...

    Open Energy Info (EERE)

    Unknown Exploration Basis Faulder 1991 Conceptual Geological Model compilation and literature review of the Roosevelt Hot Springs Geothermal Area. Notes P-wave passive seismic...

  20. Micro-Earthquake At Chena Geothermal Area (Holdmann, Et Al.,...

    Open Energy Info (EERE)

    Activity Date 2006 - 2007 Usefulness not indicated DOE-funding Unknown Exploration Basis Microseismic- Exploration program undertaken by the DOE-funded Geothermal Resource...

  1. Micro-Earthquake At Coso Geothermal Area (2011) | Open Energy...

    Open Energy Info (EERE)

    DOE-funding Unknown Exploration Basis To analyze temporal velocity variations Notes Microseismic data recorded between 1996 and 2008 was used to determine the temporally...

  2. Micro-Earthquake At Under Steamboat Springs Area (Warpinski,...

    Open Energy Info (EERE)

    running orthogonal to each other which are presumably related to the fault system. The microseismic survey resulted in the detection of a number of shallow microseisms that...

  3. Microearthquake moment tensors from the Coso Geothermal area...

    Open Energy Info (EERE)

    which propagated to the NNE and upward. Co-injection focal mechanisms reveal combined crack-opening and shear motion. Stress release and mode of failure differed between the...

  4. Micro-Earthquake At Kilauea East Rift Geothermal Area (FURUMOTO...

    Open Energy Info (EERE)

    potential as part of the coordinated exploration program for geothermal sources on the Big Island of Hawaii. Notes A two week micro-seismic study in the Puna district was...

  5. Micro-Earthquake At Coso Geothermal Area (2000) | Open Energy...

    Open Energy Info (EERE)

    5 km. It was calculate that there are 375 good quality mini-array beamed receiver functions for teleseismic events. References Gilbert, H.J.; Wilson, C.K. ; Jones, C.H.;...

  6. Micro-Earthquake At Waunita Hot Springs Geothermal Area (Lange...

    Open Energy Info (EERE)

    assess the extent of active fault failure and the potential importance of fracture permeability in the subsurface surrounding the hot springs. Notes The first documented...

  7. Micro-Earthquake At North Brawley Geothermal Area (Hauksson,...

    Open Energy Info (EERE)

    data is available to be used for a more localized studies. References E. Hauksson, W. Yang, P. M. Shearer (2012) Waveform Relocated Earthquake Catalog for Southern California...

  8. Micro-Earthquake At Raft River Geothermal Area (1982) | Open...

    Open Energy Info (EERE)

    Zandt, G.; Mcpherson, L.; Schaff, S.; Olsen, S. (1 May 1982) Seismic baseline and induction studies- Roosevelt Hot Springs, Utah and Raft River, Idaho Additional References...

  9. Micro-Earthquake At Roosevelt Hot Springs Geothermal Area (Zandt...

    Open Energy Info (EERE)

    Zandt, G.; Mcpherson, L.; Schaff, S.; Olsen, S. (1 May 1982) Seismic baseline and induction studies- Roosevelt Hot Springs, Utah and Raft River, Idaho Additional References...

  10. Micro-Earthquake At Coso Geothermal Area (1996) | Open Energy...

    Open Energy Info (EERE)

    at 0.5 to 1.2 km in depth below Devil's Kitchen, Nicol Prospects, and Coso Hot Springs. A vertical, low Q ( 36 in contrast with surrounding rock of 80) region is interpreted as...

  11. Non-Double-Couple Microearthquakes At Long Valley Caldera, California...

    Open Energy Info (EERE)

    shear and extensional faulting with a volume-compensating process, such as rapid flow of water, steam, or CO2 into opening tensile cracks. Source orientations of earthquakes in...

  12. Micro-Earthquake At Long Valley Caldera Geothermal Area (Foulger...

    Open Energy Info (EERE)

    shear and extensional faulting with a volume-compensating process, such as rapid flow of water, steam, or CO2 into opening tensile cracks. Source orientations of earthquakes in...

  13. Micro-Earthquake At Neal Hot Springs Geothermal Area (Nichols...

    Open Energy Info (EERE)

    seismic sensor, a data acquisition system that records information onto flash drives, a solar panel and battery, and a fence to keep cows out. References Scott Nichols, David...

  14. Micro-Earthquake At Roosevelt Hot Springs Geothermal Area (Ward...

    Open Energy Info (EERE)

    Area. References S. H. Ward, W. T. Parry, W. P. Nash, W. R. Sill, K. L. Cook, R. B. Smith, D. S. Chapman, F. H. Brown, J. A. Whelan, J. R. Bowman (1978) A Summary of the...

  15. Heat flow and microearthquake studies, Coso Geothermal Area,...

    Open Energy Info (EERE)

    The sites for ten heat flow boreholes were located primarily using the available seismic ground noise and electrical resistivity data. Difficulty was encountered in the drilling...

  16. Micro-Earthquake At Kilauea East Rift Geothermal Area (Gardner...

    Open Energy Info (EERE)

    of faults as well as produce an accurate velocity model of the region. References Murray C. Gardner, James R. McNitt, Christopher W. Klein, James B. Koenig, Dean Nakano (1995)...

  17. Micro-Earthquake (Majer, 2003) | Open Energy Information

    Open Energy Info (EERE)

    DOE-funding Unknown Notes The goal of this work is to evaluate the most promising methods and approaches that may be used for improved geothermal exploration and reservoir...

  18. Micro-Earthquake At Kilauea East Rift Geothermal Area (Kenedi...

    Open Energy Info (EERE)

    identify fault and fracture orientations, and locate zones of high and low velocities. Based on earthquake sizes, locations, and depths the evidence from this study suggests...

  19. Statistical assessment of fish behavior from split-beam hydro-acoustic sampling

    SciTech Connect (OSTI)

    McKinstry, Craig A.; Simmons, Mary Ann; Simmons, Carver S.; Johnson, Robert L.

    2005-04-01

    Statistical methods are presented for using echo-traces from split-beam hydro-acoustic sampling to assess fish behavior in response to a stimulus. The data presented are from a study designed to assess the response of free-ranging, lake-resident fish, primarily kokanee (Oncorhynchus nerka) and rainbow trout (Oncorhynchus mykiss) to high intensity strobe lights, and was conducted at Grand Coulee Dam on the Columbia River in Northern Washington State. The lights were deployed immediately upstream from the turbine intakes, in a region exposed to daily alternating periods of high and low flows. The study design included five down-looking split-beam transducers positioned in a line at incremental distances upstream from the strobe lights, and treatments applied in randomized pseudo-replicate blocks. Statistical methods included the use of odds-ratios from fitted loglinear models. Fish-track velocity vectors were modeled using circular probability distributions. Both analyses are depicted graphically. Study results suggest large increases of fish activity in the presence of the strobe lights, most notably at night and during periods of low flow. The lights also induced notable bimodality in the angular distributions of the fish track velocity vectors. Statistical summaries are presented along with interpretations on fish behavior.

  20. Magnetic thin-film split-domain current sensor-recorder

    DOE Patents [OSTI]

    Hsieh, Edmund J.

    1979-01-01

    A sensor-recorder for recording a representation of the direction and peak amplitude of a transient current. A magnetic thin film is coated on a glass substrate under the influence of a magnetic field so that the finished film is magnetically uniaxial and anisotropic. The film is split into two oppositely magnetized contiguous domains with a central boundary by subjecting adjacent portions of the film simultaneously to magnetic fields that are opposed 180.degree.. With the split-domain sensor-recorder placed with the film plane and domain boundary either perpendicular or parallel to the expected conductive path of a transient current, the occurrence of the transient causes switching of a portion of one domain to the direction of the other domain. The amount of the switched domain portion is indicative of the amplitude of the peak current of the transient, while the particular domain that is switched is indicative of the direction of the current. The resulting domain patterns may be read with a passive magnetic tape viewer.

  1. Porous SiC nanowire arrays as stable photocatalyst for water splitting under UV irradiation

    SciTech Connect (OSTI)

    Liu, Hailong; She, Guangwei; Mu, Lixuan; Shi, Wensheng

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Arrays of porous SiC nanowires prepared by a facile in situ carbonizing method. Black-Right-Pointing-Pointer Utilizing the SiC nanowire arrays as photocatalysis for water splitting. Black-Right-Pointing-Pointer Excellent photocatalytic performance under the UV irradiation. Black-Right-Pointing-Pointer Very high stability of the SiC nanowire photocatalyst. -- Abstract: In this study, we report the fabrication and photocatalytic properties of the oriented arrays of SiC nanowires on the Si substrate. The SiC nanowire arrays were prepared by carbonizing the Si nanowire arrays with the graphite powder at 1250 Degree-Sign C. The as-prepared SiC nanowires are highly porous, which endows them with a high surface-to-volume ratio. Considering the large surface areas and the high stability, the porous SiC nanowire arrays were used as photocatalyst for water splitting under UV irradiation. It was found that such porous SiC structure exhibited an enhanced and extremely stable photocatalytic performance.

  2. Synthesis and characterization of ferrite materials for thermochemical CO2 splitting using concentrated solar energy.

    SciTech Connect (OSTI)

    Stechel, Ellen Beth; Ambrosini, Andrea; Coker, Eric Nicholas; Rodriguez, Mark Andrew; Miller, James Edward; Evans, Lindsey R.; Livers, Stephanie

    2010-07-01

    The Sunshine to Petrol effort at Sandia aims to convert carbon dioxide and water to precursors for liquid hydrocarbon fuels using concentrated solar power. Significant advances have been made in the field of solar thermochemical CO{sub 2}-splitting technologies utilizing yttria-stabilized zirconia (YSZ)-supported ferrite composites. Conceptually, such materials work via the basic redox reactions: Fe{sub 3}O{sub 4} {yields} 3FeO + 0.5O{sub 2} (Thermal reduction, >1350 C) and 3FeO + CO{sub 2} {yields} Fe{sub 3}O{sub 4} + CO (CO{sub 2}-splitting oxidation, <1200 C). There has been limited fundamental characterization of the ferrite-based materials at the high temperatures and conditions present in these cycles. A systematic study of these composites is underway in an effort to begin to elucidate microstructure, structure-property relationships, and the role of the support on redox behavior under high-temperature reducing and oxidizing environments. In this paper the synthesis, structural characterization (including scanning electron microscopy and room temperature and in-situ x-ray diffraction), and thermogravimetric analysis of YSZ-supported ferrites will be reported.

  3. Synthesis and characterization of metal oxide materials for thermochemical CO2 splitting using concentrated solar energy.

    SciTech Connect (OSTI)

    Stechel, Ellen Beth; Ambrosini, Andrea; Coker, Eric Nicholas; Rodriguez, Mark Andrew; Miller, James Edward; Evans, Lindsey R.; Livers, Stephanie

    2010-07-01

    The Sunshine to Petrol effort at Sandia aims to convert carbon dioxide and water to precursors for liquid hydrocarbon fuels using concentrated solar power. Significant advances have been made in the field of solar thermochemical CO{sub 2}-splitting technologies utilizing yttria-stabilized zirconia (YSZ)-supported ferrite composites. Conceptually, such materials work via the basic redox reactions: Fe{sub 3}O{sub 4} {yields} 3FeO + 0.5O{sub 2} (Thermal reduction, >1350 C) and 3FeO + CO{sub 2} {yields} Fe{sub 3}O{sub 4} + CO (CO{sub 2}-splitting oxidation, <1200 C). There has been limited fundamental characterization of the ferrite-based materials at the high temperatures and conditions present in these cycles. A systematic study of these composites is underway in an effort to begin to elucidate microstructure, structure-property relationships, and the role of the support on redox behavior under high-temperature reducing and oxidizing environments. In this paper the synthesis, structural characterization (including scanning electron microscopy and room temperature and in-situ x-ray diffraction), and thermogravimetric analysis of YSZ-supported ferrites will be reported.

  4. Baryon mass splittings and strong CP violation in SU(3) chiral perturbation theory

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

    de Vries, Jordy; Mereghetti, Emanuele; Walker-Loud, Andre P.

    2015-10-08

    We study SU(3) flavor breaking corrections to the relation between the octet baryon masses and the nucleon-meson CP-violating interactions induced by the QCD theta term. We also work within the framework of SU(3) chiral perturbation theory and work through next-to-next-to-leading order in the SU(3) chiral expansion, which is O(m2q). At lowest order, the CP-odd couplings induced by the QCD θ- term are determined by mass splittings of the baryon octet, the classic result of Crewther et al. We show that for each isospin-invariant CP-violating nucleon-meson interaction there exists one relation which is respected by loop corrections up to the ordermore » we work, while other leading-order relations are violated. With these relations we extract a precise value of the pion-nucleon coupling g-0 by using recent lattice QCD evaluations of the proton-neutron mass splitting. Additionally, we derive semi-precise values for CP-violating coupling constants between heavier mesons and nucleons and discuss their phenomenological impact on electric dipole moments of nucleons and nuclei.« less

  5. Sunlight-Driven Hydrogen Formation by Membrane-Supported Photoelectrochemical Water Splitting

    SciTech Connect (OSTI)

    Lewis, Nathan S.

    2014-03-26

    This report describes the significant advances in the development of the polymer-supported photoelectrochemical water-splitting system that was proposed under DOE grant number DE-FG02-05ER15754. We developed Si microwire-array photoelectrodes, demonstrated control over the material and light-absorption properties of the microwire-array photoelectrodes, developed inexpensive processes for synthesizing the arrays, and doped the arrays p-type for use as photocathodes. We also developed techniques for depositing metal-nanoparticle catalysts of the hydrogen-evolution reaction (HER) on the wire arrays, investigated the stability and catalytic performance of the nanoparticles, and demonstrated that Ni-Mo alloys are promising earth-abundant catalysts of the HER. We also developed methods that allow reuse of the single-crystalline Si substrates used for microwire growth and methods of embedding the microwire photocathodes in plastic to enable large-scale processing and deployment of the technology. Furthermore we developed techniques for controlling the structure of WO3 films, and demonstrated that structural control can improve the quantum yield of photoanodes. Thus, by the conclusion of this project, we demonstrated significant advances in the development of all components of a sunlight-driven membrane-supported photoelectrochemical water-splitting system. This final report provides descriptions of some of the scientific accomplishments that were achieved under the support of this project and also provides references to the peer-reviewed publications that resulted from this effort.

  6. Excitonic splitting and coherent electronic energy transfer in the gas-phase benzoic acid dimer

    SciTech Connect (OSTI)

    Ottiger, Philipp; Leutwyler, Samuel

    2012-11-28

    The benzoic acid dimer, (BZA){sub 2}, is a paradigmatic symmetric hydrogen bonded dimer with two strong antiparallel hydrogen bonds. The excitonic S{sub 1}/S{sub 2} state splitting and coherent electronic energy transfer within supersonically cooled (BZA){sub 2} and its {sup 13}C-, d{sub 1}-, d{sub 2}-, and {sup 13}C/d{sub 1}- isotopomers have been investigated by mass-resolved two-color resonant two-photon ionization spectroscopy. The (BZA){sub 2}-(h-h) and (BZA){sub 2}-(d-d) dimers are C{sub 2h} symmetric, hence only the S{sub 2} Leftwards-Arrow S{sub 0} transition can be observed, the S{sub 1} Leftwards-Arrow S{sub 0} transition being strictly electric-dipole forbidden. A single {sup 12}C/{sup 13}C or H/D isotopic substitution reduces the symmetry of the dimer to C{sub s}, so that the isotopic heterodimers (BZA){sub 2}-{sup 13}C, (BZA){sub 2}-(h-d), (BZA){sub 2}-(h{sup 13}C-d), and (BZA){sub 2}-(h-d{sup 13}C) show both S{sub 1} Leftwards-Arrow S{sub 0} and S{sub 2} Leftwards-Arrow S{sub 0} bands. The S{sub 1}/S{sub 2} exciton splitting inferred is {Delta}{sub exc}= 0.94 {+-} 0.1 cm{sup -1}. This is the smallest splitting observed so far for any H-bonded gas-phase dimer. Additional isotope-dependent contributions to the splittings, {Delta}{sub iso}, arise from the change of the zero-point vibrational energy upon electronic excitation and range from {Delta}{sub iso}= 3.3 cm{sup -1} upon {sup 12}C/{sup 13}C substitution to 14.8 cm{sup -1} for carboxy H/D substitution. The degree of excitonic localization/delocalization can be sensitively measured via the relative intensities of the S{sub 1} Leftwards-Arrow S{sub 0} and S{sub 2} Leftwards-Arrow S{sub 0} origin bands; near-complete localization is observed even for a single {sup 12}C/{sup 13}C substitution. The S{sub 1}/ S{sub 2} energy gap of (BZA){sub 2} is {Delta}{sub calc}{sup exc}=11 cm{sup -1} when calculated by the approximate second-order perturbation theory (CC2) method. Upon correction for vibronic quenching, this decreases to {Delta}{sub vibron}{sup exc}=2.1 cm{sup -1} [P. Ottiger et al., J. Chem. Phys. 136, 174308 (2012)], in good agreement with the observed {Delta}{sub exc}= 0.94 cm{sup -1}. The observed excitonic splittings can be converted to exciton hopping times {tau}{sub exc}. For the (BZA){sub 2}-(h-h) homodimer {tau}{sub exc}= 18 ps, which is nearly 40 times shorter than the double proton transfer time of (BZA){sub 2} in its excited state [Kalkman et al., ChemPhysChem 9, 1788 (2008)]. Thus, the electronic energy transfer is much faster than the proton-transfer in (BZA){sub 2}{sup *}.

  7. Laboratory Test Report for Fujitsu 12RLS and Mitsubishi FE12NA Mini-Split Heat Pumps

    SciTech Connect (OSTI)

    Winkler, J.

    2011-09-01

    Mini-split heat pumps are being proposed as a new retrofit option to replace resistance heating in the Pacific Northwest. NREL has previously developed a field test protocol for mini-split systems to ensure consistent results from field tests. This report focuses on the development of detailed system performance maps for mini-split heat pumps so that the potential benefits of mini-split systems can be accurately analyzed for different climate regions and housing types. This report presents laboratory test results for two mini-split heat pumps. Steady-state heating and cooling performance for the Fujitsu 12RLS and Mitsubishi FE12NA was tested under a wide range of outdoor and indoor temperatures at various compressor and fan speeds. Cycling performance for each unit was also tested under both modes of operation. Both systems performed quite well under low loads and the experimental test data aligned with manufacturer reported values. Adequate datasets were attained to promote performance modeling of these two systems in the future.

  8. A Fully Integrated Nanosystem of Semiconductor Nanowires for Direct Solar Water Splitting

    SciTech Connect (OSTI)

    Liu, Chong; Tang, Jinyao; Chen, HaoMing; Liu, Bin; Yang, Peidong

    2013-02-21

    Artificial photosynthesis, the biomimetic approach to converting sunlight?s energy directly into chemical fuels, aims to imitate nature by using an integrated system of nanostructures, each of which plays a specific role in the sunlight-to-fuel conversion process. Here we describe a fully integrated system of nanoscale photoelectrodes assembled from inorganic nanowires for direct solar water splitting. Similar to the photosynthetic system in a chloroplast, the artificial photosynthetic system comprises two semiconductor light absorbers with large surface area, an interfacial layer for charge transport, and spatially separated cocatalysts to facilitate the water reduction and oxidation. Under simulated sunlight, a 0.12percent solar-to-fuel conversion efficiency is achieved, which is comparable to that of natural photosynthesis. The result demonstrates the possibility of integrating material components into a functional system that mimics the nanoscopic integration in chloroplasts. It also provides a conceptual blueprint of modular design that allows incorporation of newly discovered components for improved performance.

  9. Antiferromagnetic resonance excitation by terahertz magnetic field resonantly enhanced with split ring resonator

    SciTech Connect (OSTI)

    Mukai, Y.; Hirori, H.; Yamamoto, T.; Kageyama, H.; Tanaka, K.

    2014-07-14

    Excitation of antiferromagnetic resonance (AFMR) in a HoFeO{sub 3} crystal combined with a split ring resonator (SRR) is studied using terahertz (THz) electromagnetic pulses. The magnetic field in the vicinity of the SRR is induced by the incident THz electric field component and excites spin oscillations that correspond to the AFMR, which are directly probed by the Faraday rotation of the polarization of a near-infrared probe pulse. The good agreement of the temperature-dependent magnetization dynamics with the calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms that the AFMR is excited by the THz magnetic field, which is enhanced at the SRR resonance frequency by a factor of 20 compared to the incident magnetic field.

  10. Interface-induced heavy-hole/light-hole splitting of acceptors in silicon

    SciTech Connect (OSTI)

    Mol, J. A.; Salfi, J.; Simmons, M. Y.; Rogge, S.; Rahman, R.; Hsueh, Y.; Klimeck, G.; Miwa, J. A.

    2015-05-18

    The energy spectrum of spin-orbit coupled states of individual sub-surface boron acceptor dopants in silicon have been investigated using scanning tunneling spectroscopy at cryogenic temperatures. The spatially resolved tunnel spectra show two resonances, which we ascribe to the heavy- and light-hole Kramers doublets. This type of broken degeneracy has recently been argued to be advantageous for the lifetime of acceptor-based qubits [R. Ruskov and C. Tahan, Phys. Rev. B 88, 064308 (2013)]. The depth dependent energy splitting between the heavy- and light-hole Kramers doublets is consistent with tight binding calculations, and is in excess of 1?meV for all acceptors within the experimentally accessible depth range (<2?nm from the surface). These results will aid the development of tunable acceptor-based qubits in silicon with long coherence times and the possibility for electrical manipulation.

  11. Flux-vector splitting algorithm for chain-rule conservation-law form

    SciTech Connect (OSTI)

    Shih, T.I.-P.; Nguyen, H.L.; Willis, E.A.; Steinthorsson, E.; Li, Z. NASA, Lewis Research Center, Cleveland, OH )

    1991-07-01

    A flux-vector splitting algorithm with Newton-Raphson iteration was developed for the 'full compressible' Navier-Stokes equations cast in chain-rule conservation-law form. The algorithm is intended for problems with deforming spatial domains and for problems whose governing equations cannot be cast in strong conservation-law form. The usefulness of the algorithm for such problems was demonstrated by applying it to analyze the unsteady, two- and three-dimensional flows inside one combustion chamber of a Wankel engine under nonfiring conditions. Solutions were obtained to examine the algorithm in terms of conservation error, robustness, and ability to handle complex flows on time-dependent grid systems. 16 refs.

  12. First-principles thermodynamic screening approach to photo-catalytic water splitting with co-catalysts

    SciTech Connect (OSTI)

    Oberhofer, Harald; Reuter, Karsten

    2013-07-28

    We adapt the computational hydrogen electrode approach to explicitly account for photo-generated charges and use it to computationally screen for viable catalyst/co-catalyst combinations for photo-catalytic water splitting. The hole energy necessary to thermodynamically drive the reaction is employed as descriptor for the screening process. Using this protocol and hybrid-level density-functional theory, we show that water oxidation on bare TiO{sub 2} surfaces is thermodynamically more complex than previously thought. This motivates a screening for suitable co-catalysts for this half-reaction, which we carry out for Au particles down to the non-scalable size regime. We find that almost all small Au clusters studied are better suited for water photo-oxidation than an extended Au(111) surface or bare TiO{sub 2} facets.

  13. Long-Term Monitoring of Mini-Split Ductless Heat Pumps in the Northeast

    SciTech Connect (OSTI)

    Ueno, K.; Loomis, H.

    2015-06-01

    Transformations, Inc. has extensive experience building their high performance housing at a variety of Massachusetts locations, in both a production and custom home setting. The majority of their construction uses mini-split heat pumps (MSHPs) for space conditioning. This research covered the long-term performance of MSHPs in Zone 5A; it is the culmination of up to 3 years' worth of monitoring in a set of eight houses. This research examined electricity use of MSHPs, distributions of interior temperatures and humidity when using simplified (two-point) heating systems in high-performance housing, and the impact of open-door/closed-door status on temperature distributions. The use of simplified space conditioning distribution (through use of MSHPs) provides significant first cost savings, which are used to offset the increased investment in the building enclosure.

  14. Circuit model optimization of a nano split ring resonator dimer antenna operating in infrared spectral range

    SciTech Connect (OSTI)

    Gneiding, N.; Zhuromskyy, O.; Peschel, U.; Shamonina, E.

    2014-10-28

    Metamaterials are comprised of metallic structures with a strong response to incident electromagnetic radiation, like, for example, split ring resonators. The interaction of resonator ensembles with electromagnetic waves can be simulated with finite difference or finite elements algorithms, however, above a certain ensemble size simulations become inadmissibly time or memory consuming. Alternatively a circuit description of metamaterials, a well developed modelling tool at radio and microwave frequencies, allows to significantly increase the simulated ensemble size. This approach can be extended to the IR spectral range with an appropriate set of circuit element parameters accounting for physical effects such as electron inertia and finite conductivity. The model is verified by comparing the coupling coefficients with the ones obtained from the full wave numerical simulations, and used to optimize the nano-antenna design with improved radiation characteristics.

  15. Strain-driven growth of GaAs(111) quantum dots with low fine structure splitting

    SciTech Connect (OSTI)

    Yerino, Christopher D.; Jung, Daehwan; Lee, Minjoo Larry; Simmonds, Paul J.; Liang, Baolai; Huffaker, Diana L.; Schneider, Christian; Unsleber, Sebastian; Vo, Minh; Kamp, Martin; Hfling, Sven

    2014-12-22

    Symmetric quantum dots (QDs) on (111)-oriented surfaces are promising candidates for generating polarization-entangled photons due to their low excitonic fine structure splitting (FSS). However, (111) QDs are difficult to grow. The conventional use of compressive strain to drive QD self-assembly fails to form 3D nanostructures on (111) surfaces. Instead, we demonstrate that (111) QDs self-assemble under tensile strain by growing GaAs QDs on an InP(111)A substrate. Tensile GaAs self-assembly produces a low density of QDs with a symmetric triangular morphology. Coherent, tensile QDs are observed without dislocations, and the QDs luminescence at room temperature. Single QD measurements reveal low FSS with a median value of 7.6??eV, due to the high symmetry of the (111) QDs. Tensile self-assembly thus offers a simple route to symmetric (111) QDs for entangled photon emitters.

  16. Energy levels and zero field splitting parameter for Fe{sup 2+} doped in ZnS

    SciTech Connect (OSTI)

    Ivaşcu, Simona

    2013-11-13

    The aim of present paper is to report the results on the modeling of the crystal field parameters of Fe{sup 2+} doped in host matrix ZnS, simulate the energy levels scheme and calculate the zero field splitting parameter D of such system. The crystal field parameters were modeled in the frame of the superposition model of crystal field and the simulation of the energy levels scheme and calculation of the zero field splitting parameters done by diagonalization the Hamiltonian of Fe{sup 2+}:ZnS system. The obtained results were disscused and compared with experimental data. Satisfactory agreement have been obtained.

  17. A study of shock mitigating materials in a split Hopkinson bar configuration

    SciTech Connect (OSTI)

    Bateman, V.I.; Bell, R.G. III; Brown, F.A.; Hansen, N.R.

    1996-12-31

    Sandia National Laboratories (SNL) designs mechanical systems with electronics that must survive high shock environments. These mechanical systems include penetrators that must survive soil, rock, and ice penetration, nuclear transportation casks that must survive transportation environments, and laydown weapons that must survive delivery impact of 125-fps. These mechanical systems contain electronics that may operate during and after the high shock environment and that must be protected from the high shock environments. A study has been started to improve the packaging techniques for the advanced electronics utilized in these mechanical systems because current packaging techniques are inadequate for these more sensitive electronics. In many cases, it has been found that the packaging techniques currently used not only do not mitigate the shock environment but actually amplify the shock environment. An ambitious goal for this packaging study is to avoid amplification and possibly attenuate the shock environment before it reaches the electronics contained in the various mechanical system. As part of the investigation of packaging techniques, a two part study of shock mitigating materials is being conducted. This paper reports the first part of the shock mitigating materials study. A study to compare three thicknesses (0.125, 0.250, and 0.500 in.) of seventeen, unconfined materials for their shock mitigating characteristics has been completed with a split Hopkinson bar configuration. The nominal input as measured by strain gages on the incident Hopkinson bar is 50 fps {at} 100 {micro}s for these tests. It is hypothesized that a shock mitigating material has four purposes: to lengthen the shock pulse, to attenuate the shock pulse, to mitigate high frequency content in the shock pulse, and to absorb energy. Both time domain and frequency domain analyses of the split Hopkinson bar data have been performed to compare the materials` achievement of these purposes.

  18. A study of shock mitigating materials in a split Hopkins bar configuration. Phase 2

    SciTech Connect (OSTI)

    Bateman, V.I.; Brown, F.A.; Hansen, N.R.

    1997-12-31

    Sandia National Laboratories (SNL) designs mechanical systems with electronics that must survive high shock environments. These mechanical systems include penetrators that must survive soil and rock penetration, nuclear transportation casks that must survive transportation environments, and laydown weapons that must survive delivery impact. These mechanical systems contain electronics that may operate during and after the high shock environment and that must be protected from the high shock environments. A study has been started to improve the packaging techniques for the advanced electronics utilized in these mechanical systems because current packaging techniques are inadequate for these sensitive electronics. In many cases, it has been found that the packaging techniques currently used not only do not mitigate the shock environment but actually amplify the shock environment. An ambitious goal for this packaging study is to avoid amplification and possibly attenuate the shock environment before it reached the electronics contained in the various mechanical systems. Here, a study to compare two thickness values, 0.125 and 0.250 in. of five materials, GE RTV 630, HS II Silicone, Polysulfide Rubber, Sylgard 184, and Teflon for their shock mitigating characteristics with a split Hopkinson bar configuration has been completed. The five materials have been tested in both unconfined and confined conditions at ambient temperature and with two applied loads of 750 {mu}{epsilon} peak (25 fps peak) with a 100 {micro}s duration, measured at 10% amplitude, and 1500 {mu}{epsilon} peak (50 fps peak) with a 100 {micro}s duration, measured at 10% amplitude. The five materials have been tested at ambient, cold ({minus}65 F), and hot (+165 F) for the unconfined condition with the 750 {mu}{epsilon} peak (25 fps peak) applied load. Time domain and frequency domain analyses of the split Hopkinson bar data have been performed to compare how these materials lengthen the shock pulse, attenuate the shock pulse, reflect high frequency content in the shock pulse, and transmit energy.

  19. Overall Photocatalytic Water Splitting with NiOx-SrTiO3 A Revised Mechanism

    SciTech Connect (OSTI)

    Townsend, Troy K.; Browning, Nigel D.; Osterloh, Frank

    2012-11-01

    NiOx (0 < x < 1) modified SrTiO3 (STO) is one of the best studied photocatalyst for overall water splitting under UV light. The established mechanism for this and many other NiOx containing catalysts assumes water oxidation to occur at the early transition metal oxide and water reduction at NiOx. Here we show that NiOx-STO is more likely a three component Ni-STO-NiO catalyst, in which STO absorbs the light, Ni reduces protons, and NiO oxidizes water. This interpretation is based on systematic H2/O2 evolution tests of appropriately varied catalyst compositions using oxidized, chemically and photochemically added nickel and NiO nanoparticle cocatalysts. Surface photovoltage (SPV) measurements reveal that Ni(0) serves as an electron trap (site for water reduction) and that NiO serves as a hole trap (site for water oxidation). Electrochemical measurements show that the overpotential for water oxidation correlates with NiO content, whereas the water reduction overpotential depends on Ni content. Photodeposition experiments with NiCl2 and H2PtCl6 on NiO-STO show that electrons are available on the STO surface, not on the NiO particles. Based on photoelectrochemistry, both NiO and Ni particles suppress the Fermi level in STO, but the effect of this shift on catalytic activity is not clear. Overall, the results suggest a revised role for NiO in NiOx-STO and in many other nickel-containing water splitting systems, including NiOx-La:KTaO3, and many layered perovskites.

  20. Tunneling splitting in double-proton transfer: Direct diagonalization results for porphycene

    SciTech Connect (OSTI)

    Smedarchina, Zorka; Siebrand, Willem; Fernández-Ramos, Antonio

    2014-11-07

    Zero-point and excited level splittings due to double-proton tunneling are calculated for porphycene and the results are compared with experiment. The calculation makes use of a multidimensional imaginary-mode Hamiltonian, diagonalized directly by an effective reduction of its dimensionality. Porphycene has a complex potential energy surface with nine stationary configurations that allow a variety of tunneling paths, many of which include classically accessible regions. A symmetry-based approach is used to show that the zero-point level, although located above the cis minimum, corresponds to concerted tunneling along a direct trans − trans path; a corresponding cis − cis path is predicted at higher energy. This supports the conclusion of a previous paper [Z. Smedarchina, W. Siebrand, and A. Fernández-Ramos, J. Chem. Phys. 127, 174513 (2007)] based on the instanton approach to a model Hamiltonian of correlated double-proton transfer. A multidimensional tunneling Hamiltonian is then generated, based on a double-minimum potential along the coordinate of concerted proton motion, which is newly evaluated at the RI-CC2/cc-pVTZ level of theory. To make it suitable for diagonalization, its dimensionality is reduced by treating fast weakly coupled modes in the adiabatic approximation. This results in a coordinate-dependent mass of tunneling, which is included in a unique Hermitian form into the kinetic energy operator. The reduced Hamiltonian contains three symmetric and one antisymmetric mode coupled to the tunneling mode and is diagonalized by a modified Jacobi-Davidson algorithm implemented in the Jadamilu software for sparse matrices. The results are in satisfactory agreement with the observed splitting of the zero-point level and several vibrational fundamentals after a partial reassignment, imposed by recently derived selection rules. They also agree well with instanton calculations based on the same Hamiltonian.

  1. High Efficiency Generation of Hydrogen Fuels Using Solar Thermochemical Splitting of Water

    SciTech Connect (OSTI)

    Heske, Clemens; Moujaes, Samir; Weimer, Alan; Wong, Bunsen; Siegal, Nathan; McFarland, Eric; Miller, Eric; Lewis, Michele; Bingham, Carl; Roth, Kurth; Sabacky, Bruce; Steinfeld, Aldo

    2011-09-29

    The objective of this work is to identify economically feasible concepts for the production of hydrogen from water using solar energy. The ultimate project objective was to select one or more competitive concepts for pilot-scale demonstration using concentrated solar energy. Results of pilot scale plant performance would be used as foundation for seeking public and private resources for full-scale plant development and testing. Economical success in this venture would afford the public with a renewable and limitless source of energy carrier for use in electric power load-leveling and as a carbon-free transportation fuel. The Solar Hydrogen Generation Research (SHGR) project embraces technologies relevant to hydrogen research under the Office of Hydrogen Fuel Cells and Infrastructure Technology (HFCIT) as well as concentrated solar power under the Office of Solar Energy Technologies (SET). Although the photoelectrochemical work is aligned with HFCIT, some of the technologies in this effort are also consistent with the skills and technologies found in concentrated solar power and photovoltaic technology under the Office of Solar Energy Technologies (SET). Hydrogen production by thermo-chemical water-splitting is a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or a combination of heat and electrolysis instead of pure electrolysis and meets the goals for hydrogen production using only water and renewable solar energy as feed-stocks. Photoelectrochemical hydrogen production also meets these goals by implementing photo-electrolysis at the surface of a semiconductor in contact with an electrolyte with bias provided by a photovoltaic source. Here, water splitting is a photo-electrolytic process in which hydrogen is produced using only solar photons and water as feed-stocks. The thermochemical hydrogen task engendered formal collaborations among two universities, three national laboratories and two private sector entities. The photoelectrochemical hydrogen task included formal collaborations with three universities and one national laboratory. The formal participants in these two tasks are listed above. Informal collaborations in both projects included one additional university (the University of Nevada, Reno) and two additional national laboratories (Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory).

  2. Blending Cr2O3 into a NiO-Ni electrocatalyst for sustained water splitting

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

    Gong, Ming; Zhou, Wu; Kenney, Michael James; Kapusta, Rich; Cowley, Sam; Wu, Yingpeng; Lu, Bingan; Lin, Meng -Chang; Wang, Di -Yan; Yang, Jiang; et al

    2015-08-24

    The rising H2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr2O3-blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr2O3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr2O3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalyst enables an alkaline electrolyzer operating at 20more » mA cm–2 at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. Thus, the non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells.« less

  3. Effect of single-particle splitting in the exact wave function of the isovectorial pairing Hamiltonian

    SciTech Connect (OSTI)

    Lerma H, S.

    2010-07-15

    The structure of the exact wave function of the isovectorial pairing Hamiltonian with nondegenerate single-particle levels is discussed. The way that the single-particle splittings break the quartet condensate solution found for N=Z nuclei in a single degenerate level is established. After a brief review of the exact solution, the structure of the wave function is analyzed and some particular cases are considered where a clear interpretation of the wave function emerges. An expression for the exact wave function in terms of the isospin triplet of pair creators is given. The ground-state wave function is analyzed as a function of pairing strength, for a system of four protons and four neutrons. For small and large values of the pairing strength a dominance of two-pair (quartets) scalar couplings is found, whereas for intermediate values enhancements of the nonscalar couplings are obtained. A correlation of these enhancements with the creation of Cooper-like pairs is observed.

  4. GW correlation effects on plutonium quasiparticle energies: changes in crystal-field splitting

    SciTech Connect (OSTI)

    Albers, Robert C; Chantis, Athanasios N; Svane, Axel; Christensen, Niels E

    2009-01-01

    We present results for the electronic structure of plutonium by using a recently developed quasiparticle self-consistent GW method (QSGW). We consider a paramagnetic solution without spin-orbit interaction as a function of volume for the face-centered cubic (fcc) unit cell. We span unit-cell volumes ranging from 10% greater than the equilibrium volume of the 8 phase to 90 % of the equivalent for the a phase of Pu. The self-consistent GW quasiparticle energies are compared to those obtained within the Local Density Approximation (LDA). The goal of the calculations is to understand systematic trends in the effects of electronic correlations on the quasiparticle energy bands of Pu as a function of the localization of the J orbitals. We show that correlation effects narrow the f bands in two significantly different ways. Besides the expected narrowing of individual f bands (flatter dispersion), we find that an even more significant effect on the f bands is a decrease in the crystal-field splitting of the different bands

  5. Study of photonmagnon coupling in a YIG-film split-ring resonant system

    SciTech Connect (OSTI)

    Bhoi, B.; Aiyar, R.; Cliff, T.; Maksymov, I. S.; Kostylev, M.; Venkataramani, N.; Prasad, S.; Stamps, R. L.

    2014-12-28

    By using the stripline Microwave VectorNetwork Analyser Ferromagnetic Resonance and Time Domain spectroscopy techniques, we study a strong coupling regime of magnons to microwave photons in the planar geometry of a lithographically formed split-ring resonator (SRR) loaded by a single-crystal epitaxial yttriumirongarnet (YIG) film. Strong anti-crossing of the photon modes of SRR and of the magnon modes of the YIG film is observed in the applied-magnetic-field resolved measurements. The coupling strength extracted from the experimental data reaches 9% at 3?GHz. Theoretically, we propose an equivalent circuit model of the SRR loaded by a magnetic film. This model follows from the results of our numerical simulations of the microwave field structure of the SRR and of the magnetisation dynamics in the YIG film driven by the microwave currents in the SRR. The results obtained with the equivalent-circuit model are in good agreement with the experiment. This model provides a simple physical explanation of the process of mode anti-crossing. Our findings are important for future applications in microwave quantum photonic devices as well as in nonlinear and magnetically tuneable metamaterials exploiting the strong coupling of magnons to microwave photons.

  6. Solar-thermal Water Splitting Using the Sodium Manganese Oxide Process & Preliminary H2A Analysis

    SciTech Connect (OSTI)

    Francis, Todd M; Lichty, Paul R; Perkins, Christopher; Tucker, Melinda; Kreider, Peter B; Funke, Hans H; Lewandowski, A; Weimer, Alan W

    2012-10-24

    There are three primary reactions in the sodium manganese oxide high temperature water splitting cycle. In the first reaction, Mn2O3 is decomposed to MnO at 1,500C and 50 psig. This reaction occurs in a high temperature solar reactor and has a heat of reaction of 173,212 J/mol. Hydrogen is produced in the next step of this cycle. This step occurs at 700C and 1 atm in the presence of sodium hydroxide. Finally, water is added in the hydrolysis step, which removes NaOH and regenerates the original reactant, Mn2O3. The high temperature solar-driven step for decomposing Mn2O3 to MnO can be carried out to high conversion without major complication in an inert environment. The second step to produce H2 in the presence of sodium hydroxide is also straightforward and can be completed. The third step, the low temperature step to recover the sodium hydroxide is the most difficult. The amount of energy required to essentially distill water to recover sodium hydroxide is prohibitive and too costly. Methods must be found for lower cost recovery. This report provides information on the use of ZnO as an additive to improve the recovery of sodium hydroxide.

  7. Nodal bilayer-splitting controlled by spin-orbit interactions in underdoped high-Tc cuprates

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

    Harrison, N.; Ramshaw, B. J.; Shekhter, A.

    2015-06-03

    The highest superconducting transition temperatures in the cuprates are achieved in bilayer and trilayer systems, highlighting the importance of interlayer interactions for high Tc. It has been argued that interlayer hybridization vanishes along the nodal directions by way of a specific pattern of orbital overlap. Recent quantum oscillation measurements in bilayer cuprates have provided evidence for a residual bilayer-splitting at the nodes that is sufficiently small to enable magnetic breakdown tunneling at the nodes. Here we show that several key features of the experimental data can be understood in terms of weak spin-orbit interactions naturally present in bilayer systems, whosemore » primary effect is to cause the magnetic breakdown to be accompanied by a spin flip. These features can now be understood to include the equidistant set of three quantum oscillation frequencies, the asymmetry of the quantum oscillation amplitudes in c-axis transport compared to ab-plane transport, and the anomalous magnetic field angle dependence of the amplitude of the side frequencies suggestive of small effective g-factors. We suggest that spin-orbit interactions in bilayer systems can further affect the structure of the nodal quasiparticle spectrum in the superconducting phase. PACS numbers: 71.45.Lr, 71.20.Ps, 71.18.+y« less

  8. Combinatorial Development of Water Splitting Catalysts Based on the Oxygen Evolving Complex of Photosystem II

    SciTech Connect (OSTI)

    Woodbury, Neal

    2010-03-31

    The use of methods to create large arrays of potential catalysts for the reaction H2O ???????????????¯???????????????????????????????  ???????????????????????????????½ O2 + 2H+ on the anode of an electrolysis system were investigated. This reaction is half of the overall reaction involved in the splitting of water into hydrogen and oxygen gas. This method consisted of starting with an array of electrodes and developing patterned electrochemical approaches for creating a different, defined peptide at each position in the array. Methods were also developed for measuring the rate of reaction at each point in the array. In this way, the goal was to create and then tests many thousands of possible catalysts simultaneously. This type of approach should lead to an ability to optimize catalytic activity systematically, by iteratively designing and testing new libraries of catalysts. Optimization is important to decrease energy losses (over-potentials) associated with the water splitting reaction and thus for the generation of hydrogen. Most of the efforts in this grant period were focused on developing the chemistry and analytical methods required to create pattern peptide formation either using a photolithography approach or an electrochemical approach for dictating the positions of peptide bond formation. This involved testing a large number of different reactions and conditions. We have been able to find conditions that have allowed us to pattern peptide bond formation on both glass slides using photolithographic methods and on electrode arrays made by the company Combimatrix. Part of this effort involved generating novel approaches for performing mass spectroscopy directly from the patterned arrays. We have also been able to demonstrate the ability to measure current at each electrode due to electrolysis of water. This was performed with customized instrumentation created in collaboration with Combimatrix. In addition, several different molecular designs for peptides that bound metals (primarily Mn) were developed and synthesized and metal binding was demonstrated. Finally, we investigated a number of methods. We have shown that we can create surfaces on glass slides appropriate for patterning peptide formation and have made arrays of peptides as large as 30,000 using photolithographic methods. However, side reactions with certain amino acid additions greatly limited the utility of the photolithographic approach. In addition, we found that transferring this patterned chemistry approach to large arrays was problematic. Thus, we turned to direct electrochemical patterning using the Combimatrix electrode arrays. Here we were also able to demonstrate patterned peptide bond forming chemistry, but yield and consistency of the reaction remains insufficient to create the quality of array required for realistic optimization of catalytic peptide sequences. We are currently exploring both new polymerization chemistries for generating catalysts on surface as well as adopting methods developed at Intel for creating peptide arrays directly on electronic substrates (silicon wafers).

  9. Atomic layer deposition grown MO{sub x} thin films for solar water splitting: Prospects and challenges

    SciTech Connect (OSTI)

    Singh, Trilok; Lehnen, Thomas; Leuning, Tessa; Mathur, Sanjay

    2015-01-15

    The magnitude of energy challenge not only calls for efficient devices but also for abundant, inexpensive, and stable photoactive materials that can enable efficient light harvesting, charge separation and collection, as well as chemical transformations. Photoelectrochemical systems based on semiconductor materials have the possibility to transform solar energy directly into chemical energy the so-called “solar hydrogen.” The current challenge lies in the harvesting of a larger fraction of electromagnetic spectrum by enhancing the absorbance of electrode materials. In this context, atomically precise thin films of metal oxide semiconductors and their multilayered junctions are promising candidates to integrate high surface areas with well-defined electrode–substrate interface. Given its self-limited growth mechanism, the atomic layer deposition (ALD) technique offers a wide range of capabilities to deposit and modify materials at the nanoscale. In addition, it opens new frontiers for developing precursor chemistry that is inevitable to design new processes. Herein, the authors review the properties and potential of metal oxide thin films deposited by ALD for their application in photoelectrochemical water splitting application. The first part of the review covers the basics of ALD processes followed by a brief discussion on the electrochemistry of water splitting reaction. The second part focuses on different MO{sub x} films deposited by atomic layer deposition for water splitting applications; in this section, The authors discuss the most explored MO{sub x} semiconductors, namely, Fe{sub 2}O{sub 3}, TiO{sub 2}, WO{sub 3}, and ZnO, as active materials and refer to their application as protective coatings, conductive scaffolds, or in heterojunctions. The third part deals with the current challenges and future prospects of ALD processed MO{sub x} thin films for water splitting reactions.

  10. Photocatalytic pure water splitting activities for ZnGa{sub 2}O{sub 4} synthesized by various methods

    SciTech Connect (OSTI)

    Zeng, Chunmei; Hu, Tao; Hou, Nianjun; Liu, Siyao; Gao, Wenliang; Cong, Rihong; Yang, Tao

    2015-01-15

    Highlights: High temperature solid state reaction, hydrothermal, sol-gel methods were applied. All ZnGa{sub 2}O{sub 4} samples show UV-light catalytic activities on pure water splitting. Bulk ZnGa{sub 2}O{sub 4} has a good photocatalytic activity per specific surface area. Sol-gel is a superior method to prepare nanosized ZnGa{sub 2}O{sub 4} with a high activity. The AQY for SG-ZnGa{sub 2}O{sub 4} is 2.6% for pure water splitting under 313 nm irradiation. - Abstract: We studied and compared the photocatalytic water splitting performances for ZnGa{sub 2}O{sub 4} prepared by high temperature solid state reaction (HTSSR), hydrothermal (HY) and sol-gel (SG) methods. HTSSR-ZnGa{sub 2}O{sub 4} has a relative large photocatalytic activity per surface area (1.6 ?mol/h/m{sup 2}) in pure water by UV irradiation due to its high crystallinity. The HY- and SG-samples both have small particle sizes (20?30 nm) and therefore high surface area (20 and 29 m{sup 2}/g, respectively), which leads to superior photocatalytic H{sub 2} evolution rates per unit mass (11.5 and 28.5 ?mol/h/g). The apparent quantum yield of SG-ZnGa{sub 2}O{sub 4} for pure water splitting under 313 nm irradiation is 2.6%. The existence of substantial surface defects is the major problem for HY- and SG-ZnGa{sub 2}O{sub 4}. Consequently, the usage of sacrificial agents could greatly enhance the activities and indeed the H{sub 2} evolution rates in 20 Vol. % methanol aqueous solution increase to 100 and 142 ?mol/h/g for HY- and SG-ZnGa{sub 2}O{sub 4}, respectively.

  11. A novel pillar indentation splitting test for measuring fracture toughness of thin ceramic coatings

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

    Sebastiani, Marco; Johanns, K. E.; Herbert, Erik G.; Carassiti, Fabio; Pharr, George Mathews

    2014-05-16

    Fracture toughness is an important material property that plays a role in determining the in-service mechanical performance and adhesion of thin ceramic films. Unfortunately, measuring thin film fracture toughness is affected by influences from the substrate and the large residual stresses that can exist in the films. In this paper, we explore a promising new technique that potentially overcomes these problems based on nanoindentation testing of micro-pillars produced by focused ion beam milling of the films. By making the pillar diameter approximately equal to its length, the residual stress in the pillar’s upper portion is almost fully relaxed, and whenmore » indented with a sharp Berkovich indenter, the pillars fracture by splitting at reproducible loads that are readily quantified by a sudden displacement excursion in the load displacement behavior. Cohesive finite element simulations are used to analyze and develop, for a given material, a simple relation between the critical load at failure, pillar radius, and fracture toughness. The main novel aspect of this work is that neither crack geometries nor crack sizes need to be measured post test. Furthermore, the residual stress can be measured at the same time with toughness, by comparing the indentation results from the stress-free pillars and the as-deposited film. The method is tested on three different hard coatings formed by physical vapor deposition: titanium nitride, chromium nitride, and a CrAlN/Si3N4 nanocomposite. Results compare well to independently measured values of fracture toughness for the three brittle films. The technique offers several benefits over existing methods.« less

  12. MWCNT/WO{sub 3} nanocomposite photoanode for visible light induced water splitting

    SciTech Connect (OSTI)

    Yousefzadeh, Samira; Reyhani, Ali; Naseri, Naimeh; Moshfegh, Alireza Z.

    2013-08-15

    The Multi-walled carbon nanotube (MWCNT)/WO{sub 3} nanocomposite thin films with different MWCNTs weight percentages were prepared by solgel method as visible light induced photoanode in water splitting reaction. Weight percentage of MWCNT in the all nanocomposite thin films was confirmed by TGA/DSC analysis. According to XPS analysis, oxygenated groups at the surface of the MWCNT and stoichiometric formation of WO{sub 3} thin films were determined, while the crystalline structure of the nanocomposite samples was studied by XRD indicating (0 0 2) peak of MWCNT in the monoclinic phase of WO{sub 3}. The influence of different weight percentage (wt%) of MWCNT on WO{sub 3} photoactivity showed that the electron conductivity, charge transfer and electron life time had improved as compared with the pure WO{sub 3}. Based on linear sweep voltammetry and chronoamperometry measurements, the (1 wt%) MWCNT/WO{sub 3} nanocomposite thin films photoanode has a maximum photocurrent density of ?4.5 A/m{sup 2} and electron life time of about 57 s. - Graphical abstract: Photocurrent density versus time at constant potential (0.7 V) for the WO{sub 3} films containing different MWCNT weight percentages annealed at 400 C under 1000 Wm{sup ?2} visible photo-illumination. Display Omitted - Highlights: MWCNT/ WO{sub 3} nanocomposite thin films were synthesized using solgel derived method. TGA/DSC confirmed the weight percentage of MWCNT in the all nanocomposite thin films. XPS analysis revealed that WO{sub 3} was attached on the oxygenated group of MWCNT surface. The Highest Photoelectrochemical activity is achieved for (1 wt%)MWCNT/WO{sub 3} thin film.

  13. A novel pillar indentation splitting test for measuring fracture toughness of thin ceramic coatings

    SciTech Connect (OSTI)

    Sebastiani, Marco; Johanns, K.; Herbert, Erik G.; Bemporad, Edoardo; Carassiti, Fabio; Pharr, George Mathews

    2015-01-01

    The fracture toughness of thin ceramic films is an important material property that plays a role in determining the in-service mechanical performance and adhesion of this important class of engineering materials. Unfortunately, measurement of thin film fracture toughness is affected by influences from the substrate and the large residual stresses that can exist in the films. In this paper, we explore a promising new technique that potentially overcomes these issues based on nanoindentation testing of micro-pillars produced by focused ion beam milling of the films. By making the pillar diameter approximately equal to its length, the residual stress in the upper portion of the pillar is almost fully relaxed, and when indented with a sharp Berkovich indenter, the pillars fracture by splitting at reproducible loads that are readily quantified by a sudden displacement excursion in the load displacement behavior. Cohesive finite element simulations are used for analysis and development of a simple relationship between the critical load at failure, pillar radius, and fracture toughness for a given material. The main novel aspect of this work is that neither crack geometries nor crack sizes need to be measured post test. In addition, the residual stress can be measured at the same time with toughness, by comparison of the indentation results obtained on the stress-free pillars and the as-deposited film. The method is tested on three different hard coatings created by physical vapor deposition, namely titanium nitride (TiN), chromium nitride (CrN) and a CrAlN-Si?N? nanocomposite. Results compare well to independently measured values of fracture toughness for the three brittle films. The technique offers several benefits over existing methods.

  14. A novel pillar indentation splitting test for measuring fracture toughness of thin ceramic coatings

    SciTech Connect (OSTI)

    Sebastiani, Marco; Johanns, K. E.; Herbert, Erik G.; Carassiti, Fabio; Pharr, George Mathews

    2014-05-16

    Fracture toughness is an important material property that plays a role in determining the in-service mechanical performance and adhesion of thin ceramic films. Unfortunately, measuring thin film fracture toughness is affected by influences from the substrate and the large residual stresses that can exist in the films. In this paper, we explore a promising new technique that potentially overcomes these problems based on nanoindentation testing of micro-pillars produced by focused ion beam milling of the films. By making the pillar diameter approximately equal to its length, the residual stress in the pillar’s upper portion is almost fully relaxed, and when indented with a sharp Berkovich indenter, the pillars fracture by splitting at reproducible loads that are readily quantified by a sudden displacement excursion in the load displacement behavior. Cohesive finite element simulations are used to analyze and develop, for a given material, a simple relation between the critical load at failure, pillar radius, and fracture toughness. The main novel aspect of this work is that neither crack geometries nor crack sizes need to be measured post test. Furthermore, the residual stress can be measured at the same time with toughness, by comparing the indentation results from the stress-free pillars and the as-deposited film. The method is tested on three different hard coatings formed by physical vapor deposition: titanium nitride, chromium nitride, and a CrAlN/Si3N4 nanocomposite. Results compare well to independently measured values of fracture toughness for the three brittle films. The technique offers several benefits over existing methods.

  15. COMPARISON OF RESULTS FOR QUARTER 2 SURFACE WATER SPLIT SAMPLES COLLECTED AT THE NUCLEAR FUEL SERVICES SITE, ERWIN, TENNESSEE

    SciTech Connect (OSTI)

    2013-01-21

    Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, collected split surface water samples with Nuclear Fuel Services (NFS) representatives on November 15, 2012. Representatives from the U.S. Nuclear Regulatory Commission and Tennessee Department of Environment and Conservation were also in attendance. Samples were collected at four surface water stations, as required in the approved Request for Technical Assistance number 11-018. These stations included Nolichucky River upstream (NRU), Nolichucky River downstream (NRD), Martin Creek upstream (MCU), and Martin Creek downstream (MCD). Both ORAU and NFS performed gross alpha and gross beta analyses, and the results are compared using the duplicate error ratio (DER), also known as the normalized absolute difference. A DER {<=} 3 indicates that, at a 99% confidence interval, split sample results do not differ significantly when compared to their respective one standard deviation (sigma) uncertainty (ANSI N42.22). The NFS split sample report does not specify the confidence level of reported uncertainties (NFS 2012). Therefore, standard two sigma reporting is assumed and uncertainty values were divided by 1.96. In conclusion, all DER values were less than 3 and results are consistent with low (e.g., background) concentrations.

  16. COMPARISON OF RESULTS FOR QUARTER 4 SURFACE WATER SPLIT SAMPLES COLLECTED AT THE NUCLEAR FUELS SERVICES SITE, ERWIN, TN

    SciTech Connect (OSTI)

    none,

    2013-08-15

    Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, collected split surface water samples with Nuclear Fuel Services (NFS) representatives on June 12, 2013. Representatives from the U.S. Nuclear Regulatory Commission (NRC) and the Tennessee Department of Environment and Conservation were also in attendance. Samples were collected at four surface water stations, as required in the approved Request for Technical Assistance number 11-018. These stations included Nolichucky River upstream (NRU), Nolichucky River downstream (NRD), Martin Creek upstream (MCU), and Martin Creek downstream (MCD). Both ORAU and NFS performed gross alpha and gross beta analyses, and Table 1 presents the comparison of results using the duplicate error ratio (DER), also known as the normalized absolute difference. A DER ≤ 3 indicates at a 99% confidence interval that split sample results do not differ significantly when compared to their respective one standard deviation (sigma) uncertainty (ANSI N42.22). The NFS split sample report specifies 95% confidence level of reported uncertainties (NFS 2013). Therefore, standard two sigma reporting values were divided by 1.96. In conclusion, most DER values were less than 3 and results are consistent with low (e.g., background) concentrations. The gross beta result for sample 5198W0014 was the exception. The ORAU gross beta result of 6.30 ± 0.65 pCi/L from location NRD is well above NFS's non-detected result of 1.56 ± 0.59 pCi/L. NFS's data package includes no detected result for any radionuclide at location NRD. At NRC's request, ORAU performed gamma spectroscopic analysis of sample 5198W0014 to identify analytes contributing to the relatively elevated gross beta results. This analysis identified detected amounts of naturally-occurring constituents, most notably Ac-228 from the thorium decay series, and does not suggest the presence of site-related contamination.

  17. Ternary Electrocatalysts for Oxidizing Ethanol to Carbon Dioxide: Making Ir Capable of Splitting C-C bond

    SciTech Connect (OSTI)

    Li, Meng; Cullen, David A; Sasaki, Kotaro; Marinkovic, N.; More, Karren Leslie; Adzic, Radoslav R.

    2013-01-01

    Splitting the C-C bond is the main obstacle to electroxidation of ethanol (EOR) to CO2. We recently demonstrated that the ternary PtRhSnO2 electrocatalyst can accomplish that reaction at room temperature with Rh having a unique capability to split the C-C bond. In this article we report the finding that Ir can be induced to split the C-C bond as a component of the ternary catalyst. We synthesized, characterized and compared the properties of several ternary electrocatalysts. Carbon-supported nanoparticle (NP) electrocatalysts comprising a SnO2 NP core decorated with multi-metallic nanoislands (MM = PtIr, PtRh, IrRh, PtIrRh) were prepared using a seeded growth approach. An array of characterization techniques were employed to establish the composition and architecture of the synthesized MM /SnO2 NPs, while electrochemical and in situ infrared reflection absorption spectroscopy studies elucidated trends in activity and the nature of the reaction intermediates and products. Both EOR reactivity and selectivity towards CO2 formation of several of these MM /SnO2/C electrocatalysts are significantly higher compared to conventional Pt/C and Pt/SnO2/C catalysts. We demonstrate that the PtIr/SnO2/C catalyst with high Ir content shows outstanding catalytic property with the most negative EOR onset potential and reasonably good selectivity towards ethanol complete oxidation to CO2. PtRh/SnO2/C catalysts with a moderate Rh content exhibit the highest EOR selectivity, as deduced from infrared studies.

  18. Down-conversion photoluminescence sensitizing plasmonic silver nanoparticles on ZnO nanorods to generate hydrogen by water splitting photochemistry

    SciTech Connect (OSTI)

    Kung, Po-Yen; Huang, Li-Wen; Shen, Tin-Wei; Wang, Wen-Lin; Su, Yen-Hsun; Lin, Melody I.

    2015-01-12

    Silver nanoparticles fabricated onto the surface of the ZnO nanorods form the photoanode and generate photoelectric current due to surface plasmon resonance, which serves as anode electrodes in photoelectrochemical hydrogen production. In order to increase the absorption spectrum of photoanode, organic pigments were utilized as photo-sensitizers to generate down-conversion photoluminescence to excite surface plasmon resonances of silver nanoparticles. The way of using light to carry the energy in electronic scattering regime runs the system for the enhancement of solar water splitting efficiency. It was significantly tuned in environmentally sustainable applications for power generation and development of alternative energy.

  19. Special features of the isospin splitting of the giant dipole resonance in the {sup 90}Zr nucleus

    SciTech Connect (OSTI)

    Varlamov, V. V. Peskov, N. N.; Stepanov, M. E.

    2009-02-15

    Data on the proton and neutron channels of the {sup 90}Zr photodisintegration were analyzed in detail, basic parameters of the isospin splitting of the giant dipole resonance in {sup 90}Zr being determined by the properties of these channels. New data concerning the cross sections for the partial photoneutron reactions {sup 90}Zr({gamma}, n){sup 89}Zr and {sup 90}Zr({gamma}, 2n){sup 88}Zr and resulting from a simultaneous correction of data from experiments performed in Livermore (USA) and Saclay (France) by using beams of quasimonoenergetic annihilation photons were invoked. Use was made of information about the positions on the energy scale of states characterized by different isospin values in the {sup 90}Zr nucleus and nuclei neighboring it, which are members of the respective isospin multiplet. New data on the parameters of the isospin splitting of the giant dipole resonance in the {sup 90}Zr nucleus were obtained on the basis of a global analysis of data on the giant-dipole-resonance states of the {sup 90}Zr nucleus, which are manifested in the respective photoneutron and photoproton cross sections and in their decay channels involving states of different isospin in neighboring nuclei.

  20. Toward Photochemical Water Splitting Using Band-Gap-Narrowed Semiconductors and Transition-Metal Based Molecular Catalysts

    SciTech Connect (OSTI)

    Muckerman,J.T.; Rodriguez, J.A.; Fujita, E.

    2009-06-07

    We are carrying out coordinated theoretical and experimental studies of toward photochemical water splitting using band-gap-narrowed semiconductors (BGNSCs) with attached multi-electron molecular water oxidation and hydrogen production catalysts. We focus on the coupling between the materials properties and the H{sub 2}O redox chemistry, with an emphasis on attaining a fundamental understanding of the individual elementary steps in the following four processes: (1) Light-harvesting and charge-separation of stable oxide or oxide-derived semiconductors for solar-driven water splitting, including the discovery and characterization of the behavior of such materials at the aqueous interface; (2) The catalysis of the four-electron water oxidation by dinuclear hydroxo transition-metal complexes with quinonoid ligands, and the rational search for improved catalysts; (3) Transfer of the design principles learned from the elucidation of the DuBois-type hydrogenase model catalysts in acetonitrile to the rational design of two-electron hydrogen production catalysts for aqueous solution; (4) Combining these three elements to examine the function of oxidation catalysts on BGNSC photoanode surfaces and hydrogen production catalysts on cathode surfaces at the aqueous interface to understand the challenges to the efficient coupling of the materials functions.

  1. High efficiency solar cells combining a perovskite and a silicon heterojunction solar cells via an optical splitting system

    SciTech Connect (OSTI)

    Uzu, Hisashi E-mail: npark@skku.edu; Ichikawa, Mitsuru; Hino, Masashi; Nakano, Kunihiro; Meguro, Tomomi; Yamamoto, Kenji; Hernández, José Luis; Kim, Hui-Seon; Park, Nam-Gyu E-mail: npark@skku.edu

    2015-01-05

    We have applied an optical splitting system in order to achieve very high conversion efficiency for a full spectrum multi-junction solar cell. This system consists of multiple solar cells with different band gap optically coupled via an “optical splitter.” An optical splitter is a multi-layered beam splitter with very high reflection in the shorter-wave-length range and very high transmission in the longer-wave-length range. By splitting the incident solar spectrum and distributing it to each solar cell, the solar energy can be managed more efficiently. We have fabricated optical splitters and used them with a wide-gap amorphous silicon (a-Si) solar cell or a CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cell as top cells, combined with mono-crystalline silicon heterojunction (HJ) solar cells as bottom cells. We have achieved with a 550 nm cutoff splitter an active area conversion efficiency of over 25% using a-Si and HJ solar cells and 28% using perovskite and HJ solar cells.

  2. Magnetoinfrared spectroscopy of Landau levels and Zeeman splitting of three-dimensional massless Dirac Fermions in ZrTe5

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

    R. Y. Chen; Gu, G. D.; Chen, Z. G.; Song, X. -Y.; Schneeloch, J. A.; Wang, F.; Wang, N. L.

    2015-10-22

    We present a magnetoinfrared spectroscopy study on a newly identified three-dimensional (3D) Dirac semimetal ZrTe5. We observe clear transitions between Landau levels and their further splitting under a magnetic field. Both the sequence of transitions and their field dependence follow quantitatively the relation expected for 3D massless Dirac fermions. The measurement also reveals an exceptionally low magnetic field needed to drive the compound into its quantum limit, demonstrating that ZrTe5 is an extremely clean system and ideal platform for studying 3D Dirac fermions. The splitting of the Landau levels provides direct, bulk spectroscopic evidence that a relatively weak magnetic fieldmore » can produce a sizable Zeeman effect on the 3D Dirac fermions, which lifts the spin degeneracy of Landau levels. As a result, our analysis indicates that the compound evolves from a Dirac semimetal into a topological line-node semimetal under the current magnetic field configuration.« less

  3. COMPARISON OF RESULTS FOR QUARTER 3 SURFACE WATER SPLIT SAMPLES COLLECTED AT THE NUCLEAR FUEL SERVICES SITE, ERWIN, TENNESSEE

    SciTech Connect (OSTI)

    none,

    2013-05-28

    Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, collected split surface water samples with Nuclear Fuel Services (NFS) representatives on March 20, 2013. Representatives from the U.S. Nuclear Regulatory Commission and the Tennessee Department of Environment and Conservation were also in attendance. Samples were collected at four surface water stations, as required in the approved Request for Technical Assistance number 11-018. These stations included Nolichucky River upstream (NRU), Nolichucky River downstream (NRD), Martin Creek upstream (MCU), and Martin Creek downstream (MCD). Both ORAU and NFS performed gross alpha and gross beta analyses, and Table 1 presents the comparison of results using the duplicate error ratio (DER), also known as the normalized absolute difference. A DER {<=} 3 indicates that at a 99% confidence interval, split sample results do not differ significantly when compared to their respective one standard deviation (sigma) uncertainty (ANSI N42.22). The NFS split sample report does not specify the confidence level of reported uncertainties (NFS 2013). Therefore, standard two sigma reporting is assumed and uncertainty values were divided by 1.96. In conclusion, most DER values were less than 3 and results are consistent with low (e.g., background) concentrations. The gross beta result for sample 5198W0012 was the exception. The ORAU result of 9.23 ± 0.73 pCi/L from location MCD is well above NFS's result of -0.567 ± 0.63 pCi/L (non-detected). NFS's data package included a detected result for U-233/234, but no other uranium or plutonium detection, and nothing that would suggest the presence of beta-emitting radionuclides. The ORAU laboratory reanalyzed sample 5198W0012 using the remaining portion of the sample volume and a result of 11.3 ± 1.1 pCi/L was determined. As directed, the laboratory also counted the filtrate using gamma spectrometry analysis and identified only naturally occurring or ubiquitous man-made constituents, including beta emitters that are presumably responsible for the elevated gross beta values.

  4. Excitonic fine-structure splitting in telecom-wavelength InAs/GaAs quantum dots: Statistical distribution and height-dependence

    SciTech Connect (OSTI)

    Goldmann, Elias Barthel, Stefan; Florian, Matthias; Jahnke, Frank; Schuh, Kolja

    2013-12-09

    The variation of the excitonic fine-structure splitting is studied for semiconductor quantum dots under the influence of a strain-reducing layer, utilized to shift the emission wavelength of the excitonic transition into the telecom-wavelength regime of 1.31.5 ?m. By means of a sp{sup 3}s{sup *}-tight-binding model and configuration interaction, we calculate wavelength shifts and fine-structure splittings for various quantum dot geometries. We find the splittings remaining small and even decreasing with strain-reducing layer composition for quantum dots with large height. Combined with an observed increased emission efficiency, the applicability for generation of entanglement photons is persistent.

  5. Evaluation of the Cell Voltage of Electrolytic HI Concentration for Thermochemical Water-Splitting Iodine-Sulfur Process

    SciTech Connect (OSTI)

    Tanaka, Nobuyuki; Yoshida, Mitsunori; Okuda, Hiroyuki; Sato, Hiroyuki; Kubo, Shinji; Onuki, Kaoru

    2007-07-01

    Breakdown of the cell voltage in the electro-dialysis process for concentrating HIx solution (HI-H{sub 2}O-I{sub 2} mixture) was preliminarily examined in an effort to clarify the optimal operation condition as well as to optimize the cell design for the application to the thermochemical water-splitting IS process for large-scale hydrogen production. Basic data such as electric resistance of HIx solution, overvoltage of the iodine-iodide ion redox reaction at graphite electrode, and the membrane voltage drop, were measured using HIx solution with composition of interest. Also, a methodology for estimating the cell voltage was discussed. The calculated cell voltage agreed well with the experimental one indicating the validity of the procedure adopted. (authors)

  6. COMPARISON OF RESULTS FOR QUARTER 5 SURFACE WATER SPLIT SAMPLES COLLECTED AT THE NUCLEAR FUEL SERVICES SITE ERWIN TENNESSEE

    SciTech Connect (OSTI)

    2013-09-23

    Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, collected split surface water samples with Nuclear Fuel Services (NFS) representatives on August 21, 2013. Representatives from the U.S. Nuclear Regulatory Commission (NRC) and the Tennessee Department of Environment and Conservation were also in attendance. Samples were collected at four surface water stations, as required in the approved Request for Technical Assistance number 11-018. These stations included Nolichucky River upstream (NRU), Nolichucky River downstream (NRD), Martin Creek upstream (MCU), and Martin Creek downstream (MCD). Both ORAU and NFS performed gross alpha and gross beta analyses, and the comparison of results using the duplicate error ratio (DER), also known as the normalized absolute difference, are tabulated. All DER values were less than 3 and results are consistent with low (e.g., background) concentrations.

  7. A 31?T split-pair pulsed magnet for single crystal x-ray diffraction at low temperature

    SciTech Connect (OSTI)

    Duc, F.; Frings, P.; Nardone, M.; Billette, J.; Zitouni, A.; Delescluse, P.; Bard, J.; Nicolin, J. P.; Rikken, G. L. J. A.; Fabrges, X.; Roth, T.; Detlefs, C.; Lesourd, M.; Zhang, L.

    2014-05-15

    We have developed a pulsed magnet system with panoramic access for synchrotron x-ray diffraction in magnetic fields up to 31?T and at low temperature down to 1.5?K. The apparatus consists of a split-pair magnet, a liquid nitrogen bath to cool the pulsed coil, and a helium cryostat allowing sample temperatures from 1.5 up to 250?K. Using a 1.15?MJ mobile generator, magnetic field pulses of 60?ms length were generated in the magnet, with a rise time of 16.5?ms and a repetition rate of 2 pulses/h at 31?T. The setup was validated for single crystal diffraction on the ESRF beamline ID06.

  8. Performance and evaluation of gas-engine-driven split-system cooling equipment at the Willow Grove Naval Air Station

    SciTech Connect (OSTI)

    Armstrong, P.R.; Schmelzer, J.R.

    1997-01-01

    DOE`s Federal Energy Management Program supports efforts to reduce energy use and associated expenditures within the federal sector; one such effort, the New Technology Demonstration Program (NTDP)(formerly the Test Bed Demonstration program), seeks to evaluate new energy saving US technologies and secure their more timely adoption by the federal government. This report describes the field evaluation conducted to examine the performance of a 15-ton natural-gas-engine- driven, split-system, air-conditioning unit. The unit was installed at a multiple-use building at Willow Grove Naval Air Station, a regular and reserve training facility north of Philadelphia, and its performance was monitored under the NTDP.

  9. A split-beam probe-pump-probe scheme for femtosecond time resolved protein X-ray crystallography

    SciTech Connect (OSTI)

    van Thor, Jasper J.; Madsen, Anders

    2015-01-01

    In order to exploit the femtosecond pulse duration of X-ray Free-Electron Lasers (XFEL) operating in the hard X-ray regime for ultrafast time-resolved protein crystallography experiments, critical parameters that determine the crystallographic signal-to-noise (I/σI) must be addressed. For single-crystal studies under low absorbed dose conditions, it has been shown that the intrinsic pulse intensity stability as well as mode structure and jitter of this structure, significantly affect the crystallographic signal-to-noise. Here, geometrical parameters are theoretically explored for a three-beam scheme: X-ray probe, optical pump, X-ray probe (or “probe-pump-probe”) which will allow experimental determination of the photo-induced structure factor amplitude differences, ΔF, in a ratiometric manner, thereby internally referencing the intensity noise of the XFEL source. In addition to a non-collinear split-beam geometry which separates un-pumped and pumped diffraction patterns on an area detector, applying an additional convergence angle to both beams by focusing leads to integration over mosaic blocks in the case of well-ordered stationary protein crystals. Ray-tracing X-ray diffraction simulations are performed for an example using photoactive yellow protein crystals in order to explore the geometrical design parameters which would be needed. The specifications for an X-ray split and delay instrument that implements both an offset angle and focused beams are discussed, for implementation of a probe-pump-probe scheme at the European XFEL. We discuss possible extension of single crystal studies to serial femtosecond crystallography, particularly in view of the expected X-ray damage and ablation due to the first probe pulse.

  10. Split Hopkinson Resonant Bar Test for Sonic-Frequency Acoustic Velocity and Attenuation Measurements of Small, Isotropic Geologic Samples

    SciTech Connect (OSTI)

    Nakagawa, S.

    2011-04-01

    Mechanical properties (seismic velocities and attenuation) of geological materials are often frequency dependent, which necessitates measurements of the properties at frequencies relevant to a problem at hand. Conventional acoustic resonant bar tests allow measuring seismic properties of rocks and sediments at sonic frequencies (several kilohertz) that are close to the frequencies employed for geophysical exploration of oil and gas resources. However, the tests require a long, slender sample, which is often difficult to obtain from the deep subsurface or from weak and fractured geological formations. In this paper, an alternative measurement technique to conventional resonant bar tests is presented. This technique uses only a small, jacketed rock or sediment core sample mediating a pair of long, metal extension bars with attached seismic source and receiver - the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the length and mass added to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The experiment can be conducted under elevated confining pressures up to tens of MPa and temperatures above 100 C, and concurrently with x-ray CT imaging. The described Split Hopkinson Resonant Bar (SHRB) test is applied in two steps. First, extension and torsion-mode resonance frequencies and attenuation of the entire system are measured. Next, numerical inversions for the complex Young's and shear moduli of the sample are performed. One particularly important step is the correction of the inverted Young's moduli for the effect of sample-rod interfaces. Examples of the application are given for homogeneous, isotropic polymer samples and a natural rock sample.

  11. A split-beam probe-pump-probe scheme for femtosecond time resolved protein X-ray crystallography

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

    van Thor, Jasper J.; Madsen, Anders

    2015-01-01

    In order to exploit the femtosecond pulse duration of X-ray Free-Electron Lasers (XFEL) operating in the hard X-ray regime for ultrafast time-resolved protein crystallography experiments, critical parameters that determine the crystallographic signal-to-noise (I/σI) must be addressed. For single-crystal studies under low absorbed dose conditions, it has been shown that the intrinsic pulse intensity stability as well as mode structure and jitter of this structure, significantly affect the crystallographic signal-to-noise. Here, geometrical parameters are theoretically explored for a three-beam scheme: X-ray probe, optical pump, X-ray probe (or “probe-pump-probe”) which will allow experimental determination of the photo-induced structure factor amplitude differences, ΔF,more » in a ratiometric manner, thereby internally referencing the intensity noise of the XFEL source. In addition to a non-collinear split-beam geometry which separates un-pumped and pumped diffraction patterns on an area detector, applying an additional convergence angle to both beams by focusing leads to integration over mosaic blocks in the case of well-ordered stationary protein crystals. Ray-tracing X-ray diffraction simulations are performed for an example using photoactive yellow protein crystals in order to explore the geometrical design parameters which would be needed. The specifications for an X-ray split and delay instrument that implements both an offset angle and focused beams are discussed, for implementation of a probe-pump-probe scheme at the European XFEL. We discuss possible extension of single crystal studies to serial femtosecond crystallography, particularly in view of the expected X-ray damage and ablation due to the first probe pulse.« less

  12. Transjugular Intrahepatic Porto-Systemic Shunt Placement in a Patient with Left-Lateral Split-Liver Transplant and Mesenterico-Left Portal Vein by Pass Placement

    SciTech Connect (OSTI)

    Miraglia, Roberto Maruzzelli, Luigi; Luca, Angelo

    2011-12-15

    This is a report of a successful placement of a transjugular intrahepatic porto-systemic shunt in a young patient with previous left-lateral, split-liver transplant and mesenterico-left portal vein by pass placement after posttransplant extrahepatic portal vein thrombosis.

  13. Demonstration of split-flow ventilation and recirculation as flow-reduction methods in an Air Force paint spray booth. Final technical report, February 1991-October 1992

    SciTech Connect (OSTI)

    Hughes, S.; Ayer, J.; Sutay, R.

    1994-07-01

    During a series of painting operations in a horizontal-flow paint spray booth at Travis AFB, CA, baseline concentrations of four classes of toxic airborne pollutants were measured at 24 locations across a plane immediately forward of the exhaust filters, in the exhaust duct, and inside and outside the respirator in the painter`s breathing zone (BZ). The resulting data were analyzed and used to design a modified ventilation system that (1) separates a portion of the exhaust exiting the lower portion of the booth, which contains a concentration of toxic pollutants greater than the average at the exhaust plane (split-flow); and (2) provides an option to return the flow from the upper portion of the exhaust to the intake plenum for mixing with fresh air and recirculation through the booth (recirculation). After critical review by cognizant Air Force offices and an experimental demonstration showing that a flame ionization detector monitoring the air entering the booth is able to detect excursions above the equivalent exposure limit for the solvents in the paint, the exhaust duct was reconfigured for split-flow and recirculating ventilation. A volunteer painter was briefed on the increased risk of exposure during recirculation, and on the purposes and possible benefits of this study. He then signed an informed consent form before participating in the recirculation tests. A series of tests generally equivalent to the baseline series was conducted during split-flow and recirculating ventilation, and three tests were performed during only split-flow ventilation.

  14. Magnetic Transitions in Iron Porphyrin Halides by Inelastic Neutron Scattering and Ab-initio Studies of Zero-Field Splittings

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

    Stavretis, Shelby E.; Atanasov, Mihail; Podlesnyak, Andrey A.; Hunter, Seth C.; Neese, Frank; Xue, Zi-Ling

    2015-10-02

    Zero-field splitting (ZFS) parameters of nondeuterated metalloporphyrins [Fe(TPP)X] (X = F, Br, I; H2TPP = tetraphenylporphyrin) are determined by inelastic neutron scattering (INS). The ZFS values are D = 4.49(9) cm–1 for tetragonal polycrystalline [Fe(TPP)F], and D = 8.8(2) cm–1, E = 0.1(2) cm–1 and D = 13.4(6) cm–1, E = 0.3(6) cm–1 for monoclinic polycrystalline [Fe(TPP)Br] and [Fe(TPP)I], respectively. Along with our recent report of the ZFS value of D = 6.33(8) cm–1 for tetragonal polycrystalline [Fe(TPP)Cl], these data provide a rare, complete determination of ZFS parameters in a metalloporphyrin halide series. The electronic structure of [Fe(TPP)X] (X =more » F, Cl, Br, I) has been studied by multireference ab initio methods: the complete active space self-consistent field (CASSCF) and the N-electron valence perturbation theory (NEVPT2) with the aim of exploring the origin of the large and positive zero-field splitting D of the 6A1 ground state. D was calculated from wave functions of the electronic multiplets spanned by the d5 configuration of Fe(III) along with spin–orbit coupling accounted for by quasi degenerate perturbation theory. Results reproduce trends of D from inelastic neutron scattering data increasing in the order from F, Cl, Br, to I. A mapping of energy eigenvalues and eigenfunctions of the S = 3/2 excited states on ligand field theory was used to characterize the σ- and π-antibonding effects decreasing from F to I. This is in agreement with similar results deduced from ab initio calculations on CrX63- complexes and also with the spectrochemical series showing a decrease of the ligand field in the same directions. A correlation is found between the increase of D and decrease of the π- and σ-antibonding energies eλX (λ = σ, π) in the series from X = F to I. Analysis of this correlation using second-order perturbation theory expressions in terms of angular overlap parameters rationalizes the experimentally deduced trend. Furthermore, D parameters from CASSCF and NEVPT2 results have been calibrated against those from the INS data, yielding a predictive power of these approaches. Methods to improve the quantitative agreement between ab initio calculated and experimental D and spectroscopic transitions for high-spin Fe(III) complexes are proposed.« less

  15. Enhancing photovoltaic output power by 3-band spectrum-splitting and concentration using a diffractive micro-optic

    SciTech Connect (OSTI)

    Mohammad, Nabil; Wang, Peng; Friedman, Daniel J.; Menon, Rajesh

    2014-09-17

    We report the enhancement of photovoltaic output power by separating the incident spectrum into 3 bands, and concentrating these bands onto 3 different photovoltaic cells. The spectrum-splitting and concentration is achieved via a thin, planar micro-optical element that demonstrates high optical efficiency over the entire spectrum of interest. The optic (which we call a polychromat) was designed using a modified version of the direct-binary-search algorithm. The polychromat was fabricated using grayscale lithography. Rigorous optical characterization demonstrates excellent agreement with simulation results. Electrical characterization of the solar cells made from GaInP, GaAs and Si indicate increase in the peak output power density of 43.63%, 30.84% and 30.86%, respectively when compared to normal operation without the polychromat. This represents an overall increase of 35.52% in output power density. As a result, the potential for cost-effective large-area manufacturing and for high system efficiencies makes our approach a strong candidate for low cost solar power.

  16. Enhancing photovoltaic output power by 3-band spectrum-splitting and concentration using a diffractive micro-optic

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

    Mohammad, Nabil; Wang, Peng; Friedman, Daniel J.; Menon, Rajesh

    2014-09-17

    We report the enhancement of photovoltaic output power by separating the incident spectrum into 3 bands, and concentrating these bands onto 3 different photovoltaic cells. The spectrum-splitting and concentration is achieved via a thin, planar micro-optical element that demonstrates high optical efficiency over the entire spectrum of interest. The optic (which we call a polychromat) was designed using a modified version of the direct-binary-search algorithm. The polychromat was fabricated using grayscale lithography. Rigorous optical characterization demonstrates excellent agreement with simulation results. Electrical characterization of the solar cells made from GaInP, GaAs and Si indicate increase in the peak output powermore » density of 43.63%, 30.84% and 30.86%, respectively when compared to normal operation without the polychromat. This represents an overall increase of 35.52% in output power density. As a result, the potential for cost-effective large-area manufacturing and for high system efficiencies makes our approach a strong candidate for low cost solar power.« less

  17. Magnetoinfrared spectroscopy of Landau levels and Zeeman splitting of three-dimensional massless Dirac Fermions in ZrTe5

    SciTech Connect (OSTI)

    R. Y. Chen; Gu, G. D.; Chen, Z. G.; Song, X. -Y.; Schneeloch, J. A.; Wang, F.; Wang, N. L.

    2015-10-22

    We present a magnetoinfrared spectroscopy study on a newly identified three-dimensional (3D) Dirac semimetal ZrTe5. We observe clear transitions between Landau levels and their further splitting under a magnetic field. Both the sequence of transitions and their field dependence follow quantitatively the relation expected for 3D massless Dirac fermions. The measurement also reveals an exceptionally low magnetic field needed to drive the compound into its quantum limit, demonstrating that ZrTe5 is an extremely clean system and ideal platform for studying 3D Dirac fermions. The splitting of the Landau levels provides direct, bulk spectroscopic evidence that a relatively weak magnetic field can produce a sizable Zeeman effect on the 3D Dirac fermions, which lifts the spin degeneracy of Landau levels. As a result, our analysis indicates that the compound evolves from a Dirac semimetal into a topological line-node semimetal under the current magnetic field configuration.

  18. Intrinsic Rashba-like splitting in asymmetric Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} heterogeneous topological insulator films

    SciTech Connect (OSTI)

    Liu, Xiaofei; Guo, Wanlin

    2014-08-25

    We show by density functional theory calculations that asymmetric hetero-stacking of Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} films can modulate the topological surface states. Due to the structure inversion asymmetry, an intrinsic Rashba-like splitting of the conical surface bands is aroused. While such splitting in homogeneous Bi{sub 2}Te{sub 3}-class topological insulators can be realized in films with more than three quintuple layers under external electric fields, the hetero-stacking breaks the limit of thickness for preserving the topological nature into the thinnest two quintuple layers. These results indicate that the hetero-stacking can serve as an efficient strategy for spin-resolved band engineering of topological insulators.

  19. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    SciTech Connect (OSTI)

    Abdelaziz, Omar; Shrestha, Som S.; Munk, Jeffrey D.; Linkous, Randall Lee; Goetzler, William; Guernsey, Matt; Kassuga, Theo

    2015-10-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

  20. NREL Documents Efficiency of Mini-Split Heat Pumps (Fact Sheet), NREL Highlights, Research & Development, NREL (National Renewable Energy Laboratory)

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

    report delivers MSHP performance data for use in whole-building simulation tools. Mini-split heat pumps (MSHPs) are highly efficient refrigerant-based air conditioning and heating systems that permit room-by-room conditioning and control in homes. Because of their size, efficiency, and price, MSHPs are very popular overseas and are gaining market share in energy-efficient home upgrades in the United States. They are a good option for retrofitting older homes that lack ductwork. To evaluate MSHP

  1. Alternative Refrigerant Evaluation for High-Ambient Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    SciTech Connect (OSTI)

    Abdelaziz, Omar; Munk, Jeffrey D.; Shrestha, Som S.; Linkous, Randall Lee; Goetzler, William; Guernsey, Matt; Kassuga, Theo

    2015-08-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient Temperature Testing Program for Low-GWP Refrigerants aims to develop an understanding of the performance of low-Global Warming Potential (low-GWP) alternatives to Hydrochlorofluorocarbon (HCFC) and Hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high ambient temperature conditions. This interim working paper describes the parties involved, the alternative refrigerants selection process, the test procedures, and the preliminary results.

  2. Building America Technology Solutions for New and Existing Homes: Long-Term Monitoring of Mini-Split Ductless Heat Pumps in the Northeast, Devens and Easthampton, Massachusetts

    Broader source: Energy.gov [DOE]

    In this project, Building Science Corporation evaluated the long-term performance of mini-split heat pumps (MSHPs) in 8 homes during a period of 3 years. The work examined electrical use of MSHPs, distributions of interior temperatures and humidity when using simplified (two-point) heating systems in high-performance housing, and the impact of open-door/closed-door status on temperature distributions.

  3. A streamline splitting pore-network approach for computationally inexpensive and accurate simulation of transport in porous media

    SciTech Connect (OSTI)

    Mehmani, Yashar; Oostrom, Martinus; Balhoff, Matthew

    2014-03-20

    Several approaches have been developed in the literature for solving flow and transport at the pore-scale. Some authors use a direct modeling approach where the fundamental flow and transport equations are solved on the actual pore-space geometry. Such direct modeling, while very accurate, comes at a great computational cost. Network models are computationally more efficient because the pore-space morphology is approximated. Typically, a mixed cell method (MCM) is employed for solving the flow and transport system which assumes pore-level perfect mixing. This assumption is invalid at moderate to high Peclet regimes. In this work, a novel Eulerian perspective on modeling flow and transport at the pore-scale is developed. The new streamline splitting method (SSM) allows for circumventing the pore-level perfect mixing assumption, while maintaining the computational efficiency of pore-network models. SSM was verified with direct simulations and excellent matches were obtained against micromodel experiments across a wide range of pore-structure and fluid-flow parameters. The increase in the computational cost from MCM to SSM is shown to be minimal, while the accuracy of SSM is much higher than that of MCM and comparable to direct modeling approaches. Therefore, SSM can be regarded as an appropriate balance between incorporating detailed physics and controlling computational cost. The truly predictive capability of the model allows for the study of pore-level interactions of fluid flow and transport in different porous materials. In this paper, we apply SSM and MCM to study the effects of pore-level mixing on transverse dispersion in 3D disordered granular media.

  4. Internal split field generator

    DOE Patents [OSTI]

    Thundat; Thomas George (Knoxville, TN); Van Neste, Charles W. (Kingston, TN); Vass, Arpad Alexander (Oak Ridge, TN)

    2012-01-03

    A generator includes a coil of conductive material. A stationary magnetic field source applies a stationary magnetic field to the coil. An internal magnetic field source is disposed within a cavity of the coil to apply a moving magnetic field to the coil. The stationary magnetic field interacts with the moving magnetic field to generate an electrical energy in the coil.

  5. External split field generator

    DOE Patents [OSTI]

    Thundat, Thomas George (Knoxville, TN); Van Neste, Charles W. (Kingston, TN); Vass, Arpad Alexander (Oak Ridge, TN)

    2012-02-21

    A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

  6. Micro-Earthquake At Coso Geothermal Area (1993-1994) | Open Energy...

    Open Energy Info (EERE)

    the injection wells. References Feng, Q.; Lees, J.M. (15 April 1998) Microseismicity, stress, and fracture in the Coso geothermal field, California Additional References Retrieved...

  7. Modeling fault-zone guided waves of microearthquakes in a geothermal...

    Open Energy Info (EERE)

    velocity structure have been estimated. It is suggested here that the identification and modeling of such guided waves is an effective tool to locate fracture-induced,...

  8. Micro-Earthquake At Geysers Area (Malin, Et Al., 2004) | Open...

    Open Energy Info (EERE)

    Peter E. Malin, Eylon Shalev, Min Lou, Silas M. Simiyu, Anastasia Stroujkova, Windy McCausland (2004) A Comprehensive Study Of Fracture Patterns And Densities In The...

  9. Micro-Earthquake At Fenton Hill HDR Geothermal Area (Brown, 2009...

    Open Energy Info (EERE)

    at 655 m depth in PC-1. Nine surface seismic stations were also operated during the MHF Test to aid in environmental monitoring. Fehler et al. (1987) developed a three point...

  10. Splitting of the pygmy dipole resonance in {sup 138}Ba and {sup 140}Ce observed in the ({alpha},{alpha}{sup '}{gamma}) reaction

    SciTech Connect (OSTI)

    Endres, J.; Hasper, J.; Zilges, A.; Savran, D.; Berg, A. M. van den; Dendooven, P.; Woertche, H. J.; Fritzsche, M.; Harakeh, M. N.

    2009-09-15

    The N=82 nuclei {sup 140}Ce and {sup 138}Ba have been investigated by means of the ({alpha},{alpha}{sup '}{gamma}) coincidence method to study the pygmy dipole resonance (PDR). The experiments have been performed at the AGOR cyclotron at KVI, Groningen, at a primary beam energy of E{sub {alpha}}=136 MeV. The Big-Bite Spectrometer and seven large-volume high-purity germanium detectors were used in coincidence to perform a simultaneous spectroscopy of the scattered {alpha} particles and the {gamma} decay. The comparison with results of nuclear resonance fluorescence experiments reveals a splitting of the PDR into two components. Up to about 6 MeV the same states that could be observed in ({gamma},{gamma}{sup '}) are also excited in {alpha}-scattering experiments, whereas the higher-lying states are missing in the ({alpha},{alpha}{sup '}{gamma}) reaction. This indicates a structural splitting of the PDR into two modes with different underlying structure.

  11. Novel, band-controlled metal oxide compositions for semiconductor-mediated photocatalytic splitting of water to produce H{sub 2}

    SciTech Connect (OSTI)

    Gupta, Narendra M.

    2013-02-05

    Semiconductor-mediated photo-catalytic dissociation of water offers a unique opportunity for the production of H{sub 2}, a sustainable source of energy. More efficient and chemically stable photo-catalysts, however, remain a vital requirement for commercial viability of this process. The recent research in my group has focused on the synthesis of several new metal oxide (MO) photo-catalysts, such as: LaInO{sub 3}, GaFeO{sub 3}, InVO{sub 4}, In{sub 2}TiO{sub 5} and nanotubular TiO{sub 2}. These samples of controlled grain morphology have been synthesized by using different synthesis protocols and with and without coating of a noble metal co-catalyst. The doping of an impurity, either at cationic or at anionic lattice site, has helped in the tailoring of band structure and making these oxides visible-light-sensitive. Our study has revealed that the surface characteristics, grain morphology, band structure, and doping-induced lattice imperfections control the photo-physical properties and overall photo-catalytic water splitting activity of these metal/MO composites [1-6]. We have demonstrated that, besides promoting certain charge-transfer steps, metal-semiconductor interfaces influence the adsorption of water molecules and their subsequent interaction with photo-generated electron-hole pair at the catalyst surface. The role played by the above-mentioned micro-structural properties in photo-catalytic water splitting process will be discussed.

  12. Technology Solutions Case Study: Long-Term Monitoring of Mini-Split Ductless Heat Pumps in the Northeast, Devens and Easthampton, Massachusetts

    SciTech Connect (OSTI)

    2015-07-01

    Transformations, Inc., has extensive experience building high-performance homes - production and custom - in a variety of Massachusetts locations and uses mini-split heat pumps (MSHPs) for space conditioning in most of its homes. The use of MSHPs for simplified space-conditioning distribution provides significant first-cost savings, which offsets the increased investment in the building enclosure. In this project, the U.S. Department of Energy Building America team Building Science Corporation evaluated the long-term performance of MSHPs in 8 homes during a period of 3 years. The work examined electrical use of MSHPs, distributions of interior temperatures and humidity when using simplified (two-point) heating systems in high-performance housing, and the impact of open-door/closed-door status on temperature distributions.

  13. Electrosprayed heterojunction WO{sub 3}/BiVO{sub 4} films with nanotextured pillar structure for enhanced photoelectrochemical water splitting

    SciTech Connect (OSTI)

    Mali, Mukund G.; Yoon, Hyun; Yoon, Sam S.; Kim, Min-woo; Swihart, Mark T.; Al-Deyab, Salem S.

    2015-04-13

    We demonstrate that the addition of a tungsten oxide (WO{sub 3}) layer beneath a bismuth vanadate (BiVO{sub 4}) photocatalyst layer with a nanotextured pillar morphology significantly increases the photocurrent density in photoelectrochemical water splitting. The WO{sub 3}-BiVO{sub 4} bilayer films produced a photocurrent of up to 3.3?mA/cm{sup 2} under illumination at 100 mW/cm{sup 2} (AM1.5 spectrum). The bilayer film was characterized by scanning electron microscopy, X-ray diffraction, and photoelectrochemical methods, which confirmed the superiority of the bilayer film in terms of its morphology and charge separation and transport ability. Both WO{sub 3} and BiVO{sub 4} were deposited by electrostatic spraying under open-air conditions, which resulted in nanotextured pillars of BiVO{sub 4} atop a smooth WO{sub 3} film. The optimal coating conditions are also reported.

  14. High-resolution wave-theory-based ultrasound reflection imaging using the split-step fourier and globally optimized fourier finite-difference methods

    DOE Patents [OSTI]

    Huang, Lianjie

    2013-10-29

    Methods for enhancing ultrasonic reflection imaging are taught utilizing a split-step Fourier propagator in which the reconstruction is based on recursive inward continuation of ultrasonic wavefields in the frequency-space and frequency-wave number domains. The inward continuation within each extrapolation interval consists of two steps. In the first step, a phase-shift term is applied to the data in the frequency-wave number domain for propagation in a reference medium. The second step consists of applying another phase-shift term to data in the frequency-space domain to approximately compensate for ultrasonic scattering effects of heterogeneities within the tissue being imaged (e.g., breast tissue). Results from various data input to the method indicate significant improvements are provided in both image quality and resolution.

  15. Enlarged Mn 3s splitting and room-temperature ferromagnetism in epitaxially grown oxygen doped Mn{sub 2}N{sub 0.86} films

    SciTech Connect (OSTI)

    Meng, M.; Wu, S. X. Ren, L. Z.; Zhou, W. Q.; Wang, Y. J.; Wang, G. L.; Li, S. W.

    2014-11-07

    Single-phase and oxygen doped Mn{sub 2}N{sub 0.86} thin films have been grown on MgO (111) by plasma-assisted molecular beam epitaxy. The films grow under tensile strain and, remarkably, they show ferromagnetic-like interactions at low temperature and ferromagnetic ordering agreed well with the Bloch-law T{sup 3/2} at room-temperature. We further demonstrate the enlarged Mn 3s splitting (6.46 eV) and its possible relation to the observed ferromagnetism. Our study not only provide a strategy for further theoretical work on oxygen doped manganese nitrides, but also shed promising light on utilizing its room-temperature FM property to fabricate spintronic devices.

  16. Characterization of subsurface fracture patterns in the Coso...

    Open Energy Info (EERE)

    the fast shear waves have predominant polarization directions for most stations. The rose diagrams of fast shear-wave particle motion suggest that there are three predominant...

  17. Chapter 4, Small Commercial and Residential Unitary and Split System HVAC Cooling Equipment-Efficiency Upgrade Evaluation Protocol: The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

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

    4: Small Commercial and Residential Unitary and Split System HVAC Cooling Equipment-Efficiency Upgrade Evaluation Protocol David Jacobson, Jacobson Energy Research Subcontract Report NREL/SR-7A30-53827 April 2013 The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures 4 - 1 Chapter 4 - Table of Contents 1 Measure Description .............................................................................................................. 2 2 Application

  18. Demonstration of split-flow ventilation and recirculation as flow-reduction methods in an Air Force paint spray booth. Final report, 15 February 1991-9 October 1992

    SciTech Connect (OSTI)

    Hughes, S.; Ayer, J.; Sutay, R.

    1994-07-27

    During a series of painting operations in a horizontal-flow paint spray booth at Travis AFB, CA, baseline concentrations of four classes of toxic airborne pollutants were measured at 24 locations across a plane immediately forward of the exhaust filters, in the exhaust duct, and inside and outside the respirator in the painter`s breathing zone (BZ). The resulting data were analyzed and used to design a modified ventilation system that (1) separates a portion of the exhaust exiting the lower portion of the booth, which contains a concentration of toxic pollutants greater than the average at the exhaust plane (split-flow); and (2) provides an option to return the flow from the upper portion of the exhaust to the intake plenum for mixing with fresh air and recirculation through the booth (recirculation). After critical review by cognizant Air Force offices and an experimental demonstration showing that a flame ionization detector monitoring the air entering the booth is able to detect excursions above the equivalent exposure limit for the solvents in the paint, the exhaust duct was reconfigured for split-flow and recirculating ventilation. A volunteer painter was briefed on the increased risk of exposure during recirculation, and on the purposes and possible benefits of this study. He then signed an informed consent form before participating in the recirculation tests. A series of tests generally equivalent to the baseline series was conducted during split-flow and recirculating ventilation, and three tests were performed during only split-flow ventilation.

  19. A single centre water splitting dye complex adsorbed on rutile TiO{sub 2}(110): Photoemission, x-ray absorption, and optical spectroscopy

    SciTech Connect (OSTI)

    Weston, Matthew; Britton, Andrew J.; Handrup, Karsten; O'Shea, James N.; Reade, Thomas J.; Champness, Neil R.

    2011-09-21

    A single centre water splitting dye complex (aqua(2,2'-bipyridyl-4,4'-dicarboxylic acid)-(2,2':6',6''-terpyridine)Ruthenium(II)), along with a related complex ((2,2'-bipyridyl-4,4'-dicarboxylic acid)-(2,2':6',6''-terpyridine)chloride Ruthenium(II)), has been investigated using photoemission and compared to molecules with similar structures. Dye molecules were deposited in situ using ultra-high vacuum electrospray deposition, which allows for the deposition of thermally labile molecules, such as these dye molecules. Adsorption of the dye molecules on the rutile TiO{sub 2}(110) surface has been studied using core-level and valence photoemission. Core-level photoemission spectra reveal that each complex bonds to the surface via deprotonation of its carboxylic acid groups. A consideration of the energy level alignments reveals that both complexes are capable of charge transfer from the adsorbed molecules to the conduction band of the rutile TiO{sub 2} substrate.

  20. Blending Cr2O3 into a NiO-Ni electrocatalyst for sustained water splitting

    SciTech Connect (OSTI)

    Gong, Ming; Zhou, Wu; Kenney, Michael James; Kapusta, Rich; Cowley, Sam; Wu, Yingpeng; Lu, Bingan; Lin, Meng -Chang; Wang, Di -Yan; Yang, Jiang; Hwang, Bing -Joe; Dai, Hongjie

    2015-08-24

    The rising H2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr2O3-blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr2O3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr2O3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalyst enables an alkaline electrolyzer operating at 20 mA cm2 at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. Thus, the non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells.

  1. Development and validation of a radial inflow turbine model for simulation of the SNL S-CO2 split-flow loop.

    SciTech Connect (OSTI)

    Vilim, R. B.

    2012-07-31

    A one-dimensional model for a radial inflow turbine has been developed for super-critical carbon dioxide (S-CO{sub 2}) Brayton cycle applications. The model accounts for the main phenomena present in the volute, nozzle, and impeller of a single-stage turbine. These phenomena include internal losses due to friction, blade loading, and angle of incidence and parasitic losses due to windage and blade-housing leakage. The model has been added as a component to the G-PASS plant systems code. The model was developed to support the analysis of S-CO{sub 2} cycles in conjunction with small-scale loop experiments. Such loops operate at less than a MWt thermal input. Their size permits components to be reconfigured in new arrangements relatively easily and economically. However, the small thermal input combined with the properties of carbon dioxide lead to turbomachines with impeller diameters of only one to two inches. At these sizes the dominant phenomena differ from those in larger more typical machines. There is almost no treatment in the literature of turbomachines at these sizes. The present work therefore is aimed at developing turbomachine models that support the task of S-CO{sub 2} cycle analysis using small-scale tests. Model predictions were compared against data from an experiment performed for Sandia National Laboratories in the split-flow Brayton cycle loop currently located at Barber-Nichols Inc. The split-flow loop incorporates two turbo-alternator-compressor (TAC) units each incorporating a radial inflow turbine and a radial flow compressor on a common shaft. The predicted thermodynamic conditions at the outlet of the turbine on the main compressor shaft were compared with measured values at different shaft speeds. Two modifications to the original model were needed to better match the experiment data. First, a representation of the heat loss from the volute downstream of the sensed inlet temperature was added. Second, an empirical multiplicative factor was applied to the Euler head and another to the head loss to bring the predicted outlet pressure into better agreement with the experiment. These changes also brought the overall efficiency of the turbine into agreement with values cited by Barber Nichols for small turbines. More generally, the quality of measurement set data can in the future be improved by additional steps taken in the design and operation of the experimental apparatus. First, a thermocouple mounted at the nozzle inlet would provide a better indication of temperature at this key point. Second, heat losses from the turbine should be measured directly. Allowing the impeller to free wheel at inlet conditions and measuring the temperature drop between inlet and outlet would provide a more accurate measure of heat loss. Finally, the enthalpy change during operation is more accurately obtained by measuring the torque on the stator using strain gauges rather than by measuring pressure and temperature at inlet and outlet to infer thermodynamic states.

  2. Process for photosynthetically splitting water

    DOE Patents [OSTI]

    Greenbaum, Elias

    1984-01-01

    The invention is an improved process for producing gaseous hydrogen and oxygen from water. The process is conducted in a photolytic reactor which contains a water-suspension of a photoactive material containing a hydrogen-liberating catalyst. The reactor also includes a volume for receiving gaseous hydrogen and oxygen evolved from the liquid phase. To avoid oxygen-inactivation of the catalyst, the reactor is evacuated continuously by an external pump which circulates the evolved gases through means for selectively recovering hydrogen therefrom. The pump also cools the reactor by evaporating water from the liquid phase. Preferably, product recovery is effected by selectively diffusing the hydrogen through a heated semipermeable membrane, while maintaining across the membrane a magnetic field gradient which biases the oxygen away from the heated membrane. This promotes separation, minimizes the back-reaction of hydrogen and oxygen, and protects the membrane.

  3. Preparation and photocatalytic activity for water splitting of Pt-Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays

    SciTech Connect (OSTI)

    Liu, Jing; Liu, Jiawen; Li, Zhonghua

    2013-02-15

    Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays were prepared by hydrothermal method from Ta{sub 2}O{sub 5} nanotube arrays, obtained by anodization of Ta foils, in Na{sub 2}CO{sub 3} solution at 150 Degree-Sign C. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV-vis diffuse reflectance spectra (UV-DRS) and X-ray photoelectron spectroscopy (XPS). Analysis results show that pyrochlore structure Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays have been successfully fabricated. The diameters and lengths of Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays are 50 nm and 4 {mu}m, respectively. The photocatalytic hydrogen production activities of the as-synthesized Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays are highly dependent on the hydrothermal reaction time and Na{sub 2}CO{sub 3} concentration, optimized reaction parameters are obtained. To further improve the photocatalytic activity for hydrogen evolution, Pt loaded Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays are prepared by photochemical reduction method. The Pt loaded samples exhibit much higher activity for hydrogen evolution than pure Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays. Moreover, the photocatalytic hydrogen properties are rather stable. - Graphical abstract: Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays were synthesized by hydrothermal method using Ta{sub 2}O{sub 5} nanotube arrays as a precursor. The loaded Pt enhances the photocatalytic activity for water splitting of Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays. Highlights: Black-Right-Pointing-Pointer Novel Na{sub 2}Ta{sub 2}O{sub 6} nanotube array films with pyrochlore structure were synthesized. Black-Right-Pointing-Pointer Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays are active for H{sub 2} evolution from aqueous CH{sub 3}OH solution. Black-Right-Pointing-Pointer The effect of hydrothermal conditions on photocatalytic activity was investigated. Black-Right-Pointing-Pointer Pt loading can improve the photocatalytic activities of Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays. Black-Right-Pointing-Pointer Photocatalytic mechanism is proposed based on the experimental results.

  4. Final Report DOE Contract No. DE-FG36-04G014294 ICEKAP 2004: A Collaborative Joint Geophysical Imaging Project at Krafla and IDDP P.E. Malin, S.A. Onacha, E. Shalev Division of Earth and Ocean Sciences Nicholas School of the Environment Duke University Durham, NC 27708

    SciTech Connect (OSTI)

    Malin, Peter E.; Shalev, Eylon; Onacha, Stepthen A.

    2006-12-15

    In this final report, we discuss both theoretical and applied research resulting from our DOE project, ICEKAP 2004: A Collaborative Joint Geophysical Imaging Project at Krafla and IDDP. The abstract below begins with a general discussion of the problem we addressed: the location and characterization of blind geothermal resources using microearthquake and magnetotelluric measurements. The abstract then describes the scientific results and their application to the Krafla geothermal area in Iceland. The text following this abstract presents the full discussion of this work, in the form of the PhD thesis of Stephen A. Onacha. The work presented here was awarded the Best Geophysics Paper at the 2005 Geothermal Resources Council meeting, Reno. This study presents the modeling of buried fault zones using microearthquake and electrical resistivity data based on the assumptions that fluid-filled fractures cause electrical and seismic anisotropy and polarization. In this study, joint imaging of electrical and seismic data is used to characterize the fracture porosity of the fracture zones. P-wave velocity models are generated from resistivity data and used in locating microearthquakes. Fracture porosity controls fluid circulation in the hydrothermal systems and the intersections of fracture zones close to the heat source form important upwelling zones for hydrothermal fluids. High fracture porosity sites occur along fault terminations, fault-intersection areas and fault traces. Hydrothermal fault zone imaging using resistivity and microearthquake data combines high-resolution multi-station seismic and electromagnetic data to locate rock fractures and the likely presence fluids in high temperature hydrothermal systems. The depths and locations of structural features and fracture porosity common in both the MT and MEQ data is incorporated into a joint imaging scheme to constrain resistivity, seismic velocities, and locations of fracture systems. The imaging of the fault zones is constrained by geological, drilling, and geothermal production data. The objective is to determine interpretation techniques for evaluating structural controls of fluid circulation in hydrothermal systems. The conclusions are: directions of MT polarization and anisotropy and MEQ S-splitting correlate. Polarization and anisotropy are caused by fluid filled fractures at the base of the clay cap. Microearthquakes occur mainly on the boundary of low resistivity within the fracture zone and high resistivity in the host rock. Resistivity is lowest within the core of the fracture zone and increases towards the margins of the fracture zone. The heat source and the clay cap for the hydrothermal have very low resistivity of less than 5?m. Fracture porosity imaged by resistivity indicates that it varies between 45-5% with most between 10-20%, comparable to values from core samples in volcanic areas in Kenya and Iceland. For resistivity values above 60?m, the porosity reduces drastically and therefore this might be used as the upper limit for modeling fracture porosity from resistivity. When resistivity is lower than 5?m, the modeled fracture porosity increases drastically indicating that this is the low resistivity limit. This is because at very low resistivity in the heat source and the clay cap, the resistivity is dominated by ionic conduction rather than fracture porosity. Microearthquakes occur mainly above the heat source which is defined by low resistivity at a depth of 3-4.5 km at the Krafla hydrothermal system and 4-7 km in the Longonot hydrothermal system. Conversions of S to P waves occur for microearthquakes located above the heat source within the hydrothermal system. Shallow microearthquakes occur mainly in areas that show both MT and S-wave anisotropy. S-wave splitting and MT anisotropy occurs at the base of the clay cap and therefore reflects the variations in fracture porosity on top of the hydrothermal system. In the Krafla hydrothermal system in Iceland, both MT polarization and MEQ splitting directions align with

  5. Demonstration of split-flow ventilation and recirculation as flow-reduction methods in an Air Force paint spray booth. Volume 2. Final report, 15 February 1991-9 January 1992

    SciTech Connect (OSTI)

    Hughes, S.; Ayer, J.; Sutay, R.

    1994-07-27

    During a series of painting operations in a horizontal-flow paint spray booth at Travis AFB, CA, baseline concentrations of four classes of toxic airborne pollutants were measured at 24 locations across a plane immediately forward of the exhaust filters, in the exhaust duct, and inside and outside the respirator in the painter`s breathing zone (BZ). The resulting data were analyzed and used to design a modified ventilation system that (1) separates a portion of the exhaust exiting the lower portion of the booth, which contains a concentration of toxic pollutants greater than the average at the exhaust plane (split-flow); and (2) provides an option to return the flow from the upper portion of the exhaust to the intake plenum for mixing with fresh air and recirculation through the booth (recirculation). After critical review by cognizant Air Force offices, and an experimental demonstration showing that a flame ionization detector monitoring the air entering the booth is able to detect excursions above the equivalent exposure limit for the solvents in the paint, the exhaust duct was reconfigured for split-flow and recirculating ventilation.

  6. Demonstration of split-flow ventilation and recirculation as flow-reduction methods in an Air Force paint spray booth. Volume 1. Final report, 15 February 1991-9 January 1992

    SciTech Connect (OSTI)

    Hughes, S.; Ayer, J.; Sutay, R.

    1994-07-27

    During a series of painting operations in a horizontal-flow paint spray booth at Travis AFB, CA, baseline concentrations of four classes of toxic airborne pollutants were measured at 24 locations across a plane immediately forward of the exhaust filters, in the exhaust duct, and inside and outside the respirator in the painter`s breathing zone (BZ). The resulting data were analyzed and used to design a modified ventilation system that (1) separates a portion of the exhaust exiting the lower portion of the booth, which contains a concentration of toxic pollutants greater than the average at the exhaust plane (split-flow); and (2) provides an option to return the flow from the upper portion of the exhaust to the intake plenum for mixing with fresh air and recirculation through the booth (recirculation). After critical review by cognizant Air Force offices, and an experimental demonstration showing that a flame ionization detector monitoring the air entering the booth is able to detect excursions above the equivalent exposure limit for the solvents in the paint the exhaust duct was reconfigured for split-flow and recirculating ventilation.

  7. Experimental results of an electron cyclotron resonance oxygen source and a low energy beam transport system for 1 MeV integral split ring radio frequency quadruple accelerator upgrade project

    SciTech Connect (OSTI)

    Peng, S. X.; Zhang, M.; Song, Z. Z.; Xu, R.; Zhao, J.; Yuan, Z. X.; Yu, J. X.; Chen, J.; Guo, Z. Y.

    2008-02-15

    To meet the requirements of developing separated function radio frequency quadruple (rfq) and upgrading the 1 MeV integral split ring rfq accelerator, an electron cyclotron resonance O{sup +} ion source and low energy beam transport (LEBT) system have been developed. Using two Einzel lenses to focus the beam, more than 6 mA O{sup +} peak beam current with energy of 22 keV can be easily obtained at the end of LEBT when the duty faction is at 1/6. The normalized root-mean-square emittance of 90% of the beam is about 0.12{pi} mm mrad. By changing the focusing power of lenses, the beam waist can be shifted from 80 mm before the beam diaphragm 2 to 80 mm after it. The experimental results will be presented in this article.

  8. Closing the circle on the splitting of the atom: The environmental legacy of nuclear weapons production in the United States and what the Department of Energy is doing about it

    SciTech Connect (OSTI)

    1996-01-01

    In the grand scheme of things we are a little more than halfway through the cycle of splitting the atom for weapons purposes. If we visualize this historic cycle as the full sweep of a clockface, at zero hour we would find the first nuclear chain reaction by Enrico Fermi, followed immediately by the Manhattan Project and the explosion of the first atomic bombs. From two o`clock until five, the United States built and ran a massive industrial complex that produced tens of thousands of nuclear weapons. At half past, the Cold War ended, and the United States shut down most of its nuclear weapons factories. The second half of this cycle involves dealing with the waste and contamination from nuclear weapons production - a task that had, for the most part, been postponed into the indefinite future. That future is now upon us. Dealing with the environmental legacy of the Cold War is in many ways as big a challenge for us today as the building of the atomic bomb was for the Manhattan Project pioneers in the 1940s. Our challenges are political and social as well as technical, and we are meeting those challenges. We are reducing risks, treating wastes, developing new technologies, and building democratic institutions for a constructive debate on our future course.

  9. Split-tapered joint clamping device

    DOE Patents [OSTI]

    Olsen, Max J.; Schwartz, Jr., John F.

    1988-01-01

    This invention relates to a clamping device for removably attaching a tool element to a bracket element wherein a bracket element is disposed in a groove in the tool and a clamping member is disposed in said groove and in engagement with a clamping face of the bracket and a wall of the groove and with the clamping member having pivot means engaging the bracket and about which the clamping member rotates.

  10. A Novel Split-Cycle Engine

    Broader source: Energy.gov [DOE]

    Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010.

  11. Splitting the Cycle the Right Way

    Broader source: Energy.gov [DOE]

    This presentation discusses prototype design, operation, and in-cylinder data on a novel engine concept for which models show 55% BTE.

  12. Advanced Water Splitting Materials EMN Workshop

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

    MGI - Framework Predictive Simulation Across Scales Synthesis & Characterization Rapid ... Big Data Experts Characterization Experts Synthesis Experts we're all in this together ...

  13. Atom-split it for nuclear energy

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

    adjustments were provided by the 'Calutron Girls' Seaborg-Chairman of the Atomic Energy Commission 1961-1971; discovered many elements Buckyball-Buckminsterfullerene; 60...

  14. Hydrogen Production: Thermochemical Water Splitting | Department...

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

    nuclear power reactions-and chemical reactions to produce hydrogen and oxygen from water. ... heat (500-2,000C) to drive a series of chemical reactions that produce hydrogen. ...

  15. Methanation process utilizing split cold gas recycle

    DOE Patents [OSTI]

    Tajbl, Daniel G.; Lee, Bernard S.; Schora, Jr., Frank C.; Lam, Henry W.

    1976-07-06

    In the methanation of feed gas comprising carbon monoxide and hydrogen in multiple stages, the feed gas, cold recycle gas and hot product gas is mixed in such proportions that the mixture is at a temperature sufficiently high to avoid carbonyl formation and to initiate the reaction and, so that upon complete reaction of the carbon monoxide and hydrogen, an excessive adiabatic temperature will not be reached. Catalyst damage by high or low temperatures is thereby avoided with a process that utilizes extraordinarily low recycle ratios and a minimum of investment in operating costs.

  16. Preliminary results of characteristic seismic anisotropy beneath Sunda-Banda subduction-collision zone

    SciTech Connect (OSTI)

    Wiyono, Samsul H.; Nugraha, Andri Dian

    2015-04-24

    Determining of seismic anisotropy allowed us for understanding the deformation processes that occured in the past and present. In this study, we performed shear wave splitting to characterize seismic anisotropy beneath Sunda-Banda subduction-collision zone. For about 1,610 XKS waveforms from INATEWS-BMKG networks have been analyzed. From its measurements showed that fast polarization direction is consistent with trench-perpendicular orientation but several stations presented different orientation. We also compared between fast polarization direction with absolute plate motion in the no net rotation and hotspot frame. Its result showed that both absolute plate motion frame had strong correlation with fast polarization direction. Strong correlation between the fast polarization direction and the absolute plate motion can be interpreted as the possibility of dominant anisotropy is in the asthenosphere.

  17. Seismicity Protocol | Department of Energy

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

    for Characterizing Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report Microearthquake Technology for EGS Fracture Characterization Monitoring...

  18. Towards the Understanding of Induced Seismicity in Enhanced Geothermal...

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

    Continuum through Discontinuum Representations: Capturing Reservoir Stimulation, Evolution and Induced Seismicity Microearthquake Technology for EGS Fracture Characterization

  19. Mapping Diffuse Seismicity for Geothermal Reservoir Management with Matched Field Processing

    Broader source: Energy.gov [DOE]

    Project objective: to detect and locate more microearthquakes observed during EGS operations using the matched field processing (MFP) technique.

  20. Development of an Updated Induced Seismicity Protocol for the Application

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

    of Microearthquake (MEQ) Monitoring for Characterizing Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report | Department of Energy Development of an Updated Induced Seismicity Protocol for the Application of Microearthquake (MEQ) Monitoring for Characterizing Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report Development of an Updated Induced Seismicity Protocol for the Application of Microearthquake (MEQ) Monitoring for

  1. Magnetorotational instability: nonmodal growth and the relationship...

    Office of Scientific and Technical Information (OSTI)

    well described by the ordinary differential equations (ODEs) governing a single shear wave, we find that the shearing box is a very sensible approximation for the linear MRI,...

  2. Temporal Velocity Variations beneath the Coso Geothermal Field...

    Open Energy Info (EERE)

    Double Difference Tomography of Compressional and Shear Wave Arrival Times Abstract Microseismic imaging can be an important tool for characterizing geothermal reservoirs....

  3. Savannah River Site - Salt Waste Processing Facility Independent...

    Office of Environmental Management (EM)

    ... Safety Management System ITR ... Safety Integrity Level SPF Saltstone ... velocity V S, Low low strain shear wave WAC Waste Acceptance Criteria xii SPD-SWPF-217: ...

  4. Characterizing Fractures in the Geysers Geothermal Field by Micro...

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

    Fractures in the Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy Characterizing Fractures in the Geysers Geothermal Field...

  5. Teleseismic-Seismic Monitoring At Coso Geothermal Area (1983...

    Open Energy Info (EERE)

    Exploration Basis To study anomalous shear wave attenuation in the shallow crust Notes V s and V p wave amplitudes were measured from vertical component seismograms of...

  6. Solar Water Splitting: Putting an Extra "Eye" on Surface Reactions...

    Office of Science (SC) Website

    ... Science, Geosciences, and Biosciences Division, Solar Photochemistry Program, under Grant DE-FG02-12ER16323. S.W.B. acknowledges support from the DuPont Young Professor Program. ...

  7. Particle Splitting for Monte-Carlo Simulation of the National...

    Office of Scientific and Technical Information (OSTI)

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is scheduled for completion in 2009. Thereafter, experiments will commence in which capsules of ...

  8. Internal/External Split Field Generator - Energy Innovation Portal

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

    lower cost, higher power density generator is ... magnetic field to generate an electrical energy in the coil. ... The first and second stationary magnetic field sources apply ...

  9. Ductless Mini-Split Heat Pump Comfort Evaluation

    SciTech Connect (OSTI)

    Roth, K.; Sehgal, N.; Akers, C.

    2013-03-01

    Field tests were conducted in two homes in Austin, TX, to evaluate the comfort performance of ductless minisplit heat pumps (DMSHPs), measuring temperature and relative humidity measurements in four rooms in each home before and after retrofitting a central HVAC system with DMSHPs.

  10. Improving the efficiency of water splitting in dye-sensitized...

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

    bound to the water oxidation catalyst, a colloidal iridium oxide particle, and is coadsorbed onto a porous titanium dioxide electrode with a Ruthenium polypyridyl sensitizer. ...

  11. Two Electron Holes in Hematite Facilitate Water Splitting

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

    of Energy Two Companies Recognized for Leadership in Energy Efficiency Two Companies Recognized for Leadership in Energy Efficiency November 27, 2013 - 12:00am Addthis The Energy Department on November 22 recognized aluminum manufacturer Alcoa and steel manufacturer ArcelorMittal for leadership in the Energy Department's Better Buildings, Better Plants Program. As a part of the Better Plants Challenge, Alcoa has demonstrated leadership by setting an ambitious goal to reduce the energy

  12. Particle Splitting for Monte-Carlo Simulation of the National...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: Presented at: 17th Topical Meeting on Fusion Energy at the 2006 American Nuclear Society, Albuquerque, NM, United States, Nov 12 - Nov 16, 2006 ...

  13. Optical power splitter for splitting high power light

    DOE Patents [OSTI]

    English, Jr., Ronald E.; Christensen, John J.

    1995-01-01

    An optical power splitter for the distribution of high-power light energy has a plurality of prisms arranged about a central axis to form a central channel. The input faces of the prisms are in a common plane which is substantially perpendicular to the central axis. A beam of light which is substantially coaxial to the central axis is incident on the prisms and at least partially strikes a surface area of each prism input face. The incident beam also partially passes through the central channel.

  14. Optical power splitter for splitting high power light

    DOE Patents [OSTI]

    English, R.E. Jr.; Christensen, J.J.

    1995-04-18

    An optical power splitter for the distribution of high-power light energy has a plurality of prisms arranged about a central axis to form a central channel. The input faces of the prisms are in a common plane which is substantially perpendicular to the central axis. A beam of light which is substantially coaxial to the central axis is incident on the prisms and at least partially strikes a surface area of each prism input face. The incident beam also partially passes through the central channel. 5 figs.

  15. White Papers on Materials for Photoelectrochemical Water Splitting

    Broader source: Energy.gov [DOE]

    Series of white papers from the U.S. Department of Energy Photoelectrochemical Working Group (Revision: October 2013). These white papers are intended as concise living documents summarizing the unique potential and challenges faced in the R&D of promising materials classes.

  16. Heating and Cooling with Mini Splits in the Northeast

    Energy Savers [EERE]

    Energy Heat Pump Water Heater using Solid-State Energy Converters Heat Pump Water Heater using Solid-State Energy Converters Sheetak will work on developing a full scale prototype of its low cost heat pump water heater. These solid state heat pumping elements can be implemented in low cost manner which have the potential to dramatically change the way in which he heat water.<BR />Image: Sheetak Sheetak will work on developing a full scale prototype of its low cost heat pump water

  17. White Papers on Materials for Photoelectrochemical Water Splitting...

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

    Technoeconomic Analysis of Photoelectrochemical (PEC) Hydrogen Production WO3 and HPA Based System for Ultra-High Activity and Stability of Pt catalysts in PEMFC Cathodes Basic ...

  18. Water-splitting using photocatalytic porphyrin-nanotube composite devices

    DOE Patents [OSTI]

    Shelnutt, John A.; Miller, James E.; Wang, Zhongchun; Medforth, Craig J.

    2008-03-04

    A method for generating hydrogen by photocatalytic decomposition of water using porphyrin nanotube composites. In some embodiments, both hydrogen and oxygen are generated by photocatalytic decomposition of water.

  19. DOE - Office of Legacy Management -- WNI Split Rock Site - 043

    Office of Legacy Management (LM)

    Rock Site (043) Designated Name: Alternate Name: Location: Evaluation Year: Site Operations: Site Disposition: Radioactive Materials Handled: Primary Radioactive Materials...

  20. Why Do Atoms Explode When They Split? | GE Global Research

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

    by Revolutionary Onboard Turbine Reshape) - Making it Real bowman2 Is a 'Mad Max' apocalypse possible? Luis-Felipe-WillcoxM&DV Monitoring and Diagnosis of Transformers...

  1. White Papers on Materials for Photoelectrochemical Water Splitting

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

    M. Powalla, Prog. Photovolt. Res. Appl. 19 (2011) 894. 4 J. Kaneshiro, Dissertation Thesis, University of Hawaii at Mnoa, 2012. 5 S. Wojtczuk, P. Chiu, X. Zhang, D. Derkacs,...

  2. Two Electron Holes in Hematite Facilitate Water Splitting

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

    with state-of-the-art silicon-doped and nanostructured hematite photoanodes in alkaline electrolyte. They recorded near-edge x-ray absorption fine-structure (NEXAFS) spectra...

  3. Extremely stable bare hematite photoanode for solar water splitting...

    Office of Scientific and Technical Information (OSTI)

    Additional Journal Information: Journal Volume: 23; Journal Issue: C; Journal ID: ISSN 2211-2855 Publisher: Elsevier Sponsoring Org: USDOE Office of Nuclear Energy (NE), Fuel Cycle ...

  4. Split-flow regeneration in absorptive air separation

    DOE Patents [OSTI]

    Weimer, R.F.

    1987-11-24

    A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced capital costs. 4 figs.

  5. Split-flow regeneration in absorptive air separation

    DOE Patents [OSTI]

    Weimer, Robert F.

    1987-01-01

    A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced capital costs.

  6. Closing the Circle on the Splitting of the Atom

    Broader source: Energy.gov [DOE]

    This report was the first report published in the new Departmental era of openness that described existing environmental, safety, and health problems throughout the nuclear weapons complex and the cleanup challenges that DOE faced.

  7. DOE's Gasoline/Diesel PM Split Study | Department of Energy

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

    Potawatomi Community | Department of Energy Anaerobic digesters reduce pollution and generate electricity in Milwaukee. | Image from Forest County Potawatomi Community Anaerobic digesters reduce pollution and generate electricity in Milwaukee. | Image from Forest County Potawatomi Community EERE Investment $2.6 million Location Forest County, Milwaukee, Wisconsin Partners Potawatomi Tribe Project Details With Department of Energy funding and technical support, the Forest County Potawatomi

  8. This invention relates to methods of generating NP gallium nitride (GaN) across large areas (>1 cm.sup.2) with controlled pore diameters, pore density, and porosity. Also disclosed are methods of generating novel optoelectronic devices based on porous GaN. Additionally a layer transfer scheme to separate and create free-standing crystalline GaN thin layers is disclosed that enables a new device manufacturing paradigm involving substrate recycling. Other disclosed embodiments of this invention relate to fabrication of GaN based nanocrystals and the use of NP GaN electrodes for electrolysis, water splitting, or photosynthetic process applications.

    DOE Patents [OSTI]

    Zhang, Yu; Sun, Qian; Han, Jung

    2015-12-08

    This invention relates to methods of generating NP gallium nitride (GaN) across large areas (>1 cm.sup.2) with controlled pore diameters, pore density, and porosity. Also disclosed are methods of generating novel optoelectronic devices based on porous GaN. Additionally a layer transfer scheme to separate and create free-standing crystalline GaN thin layers is disclosed that enables a new device manufacturing paradigm involving substrate recycling. Other disclosed embodiments of this invention relate to fabrication of GaN based nanocrystals and the use of NP GaN electrodes for electrolysis, water splitting, or photosynthetic process applications.

  9. Microsoft Word - EPA 6 Analysis of Fracture Propagation_final...

    Office of Scientific and Technical Information (OSTI)

    ... magnitudes of microearthquakes have been too small to be reliably recorded in practice. ... and computational geomechanics communities, respectively.) We employ a sequential ...

  10. Locating an active fault zone in Coso geothermal field by analyzing...

    Open Energy Info (EERE)

    waves from microearthquake data Abstract Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems...

  11. Summary of Hot-Dry-Rock Geothermal Reservoir Testing 1978-1980...

    Open Energy Info (EERE)

    water is relatively low in total dissolved solids and shows little tendency for corrosion or scaling. The largest microearthquake associated with heat extraction measures...

  12. Hot Dry Rock Geothermal Reservoir Testing- 1978 To 1980 | Open...

    Open Energy Info (EERE)

    water is relatively low in total dissolved solids and shows little tendency for corrosion or scaling. The largest microearthquake associated with heat extraction measures...

  13. Seismic Studies of a Massive Hydraulic Fracturing Experiment...

    Open Energy Info (EERE)

    Activities Activities (1) Micro-Earthquake At Fenton Hill HDR Geothermal Area (Brown, 2009) Areas (1) Fenton Hill HDR Geothermal Area Regions (0) Retrieved from "http:...

  14. Determining Planes Along Which Earthquakes Occur- Method of Applicatio...

    Open Energy Info (EERE)

    Activities Activities (1) Micro-Earthquake At Fenton Hill HDR Geothermal Area (Brown, 2009) Areas (1) Fenton Hill HDR Geothermal Area Regions (0) Retrieved from "http:...

  15. Massive Hydraulic Fracture of Fenton Hill HDR Well EE-3 | Open...

    Open Energy Info (EERE)

    Activities Activities (1) Micro-Earthquake At Fenton Hill HDR Geothermal Area (Brown, 2009) Areas (1) Fenton Hill HDR Geothermal Area Regions (0) Retrieved from "http:...

  16. Visualization Gallery from the Computational Research Division...

    Office of Scientific and Technical Information (OSTI)

    Particle Acceleration Data; 2) Visualization of Microearthquake Data from Enhanced Geothermal Systems; 3) PointCloudXplore: Visualization and Analysis of 3D Gene Expression Data; ...

  17. Development of an Updated Induced Seismicity Protocol for the...

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

    Geothermal Technology Program Peer Review Report Microearthquake Technology for EGS Fracture Characterization; 2010 Geothermal Technology Program Peer Review Report Analysis of ...

  18. Snake River Plain Geothermal Region | Open Energy Information

    Open Energy Info (EERE)

    Survey At Snake River Plain Region (DOE GTP) Micro-Earthquake At Snake River Plain Geothermal Region (1976) Reflection Survey At Snake River Plain Region (DOE GTP)...

  19. Exploration In A Blind Geothermal Area Near Marysville, Montana...

    Open Energy Info (EERE)

    ground magnetics, resistivity, seismic ground noise, micro-earthquake studies, and infra-red photography. The heat flow data have outlined a geothermal anomaly with heat flow...

  20. Property:ExpActivityDate | Open Energy Information

    Open Energy Info (EERE)

    started or year of activity. Subproperties This property has the following 1 subproperty: M Micro-Earthquake At Kilauea East Rift Geothermal Area (FURUMOTO, 1976) Pages using the...

  1. Geophysical Characterization of a Geothermal System Neal Hot...

    Open Energy Info (EERE)

    (Colwell, Et Al., 2012) Micro-Earthquake At Neal Hot Springs Geothermal Area (Nichols & Cole, 2010) Paleomagnetic Measurements At Neal Hot Springs Geothermal Area (London, 2011)...

  2. CX-006213: Categorical Exclusion Determination | Department of...

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

    CX-006213: Categorical Exclusion Determination Recovery Act: Conducting a 3D Converted Shear Wave Project to Reduce Exploration Risk at Wister, California CX(s) Applied: A9, B3.1, ...

  3. Finite Difference Modeling of Wave Progpagation in Acoustic TiltedTI...

    Office of Scientific and Technical Information (OSTI)

    Based on an acoustic assumption (shear wave velocity is zero) and a dispersion relation, ... DOE Contract Number: DE-AC02-05CH11231 Resource Type: Journal Article Resource Relation: ...

  4. Method and apparatus for measuring stress

    DOE Patents [OSTI]

    Thompson, R. Bruce

    1985-06-11

    A method and apparatus for determining stress in a material independent of micro-structural variations and anisotropies. The method comprises comparing the velocities of two horizontally polarized and horizontally propagating ultrasonic shear waves with interchanged directions of propagation and polarization. The apparatus for carrying out the method comprises periodic permanent magnet-electromagnetic acoustic transducers for generating and detecting the shear waves and means for determining the wave velocities.

  5. Method and apparatus for measuring stress

    DOE Patents [OSTI]

    Thompson, R.B.

    1983-07-28

    A method and apparatus for determining stress in a material independent of micro-structural variations and anisotropies. The method comprises comparing the velocities of two horizontally polarized and horizontally propagating ultrasonic shear waves with interchanged directions of propagation and polarization. The apparatus for carrying out the method comprises periodic permanent magnet-electromagnetic acoustic transducers for generating and detecting the shear waves and means for determining the wave velocities.

  6. Characterizing Fractures in the Geysers Geothermal Field by Micro-seismic

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

    Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy | Department of Energy Characterizing Fractures in the Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals, and Shear Wave Anisotropy presentation at the April 2013 peer review meeting held in Denver, Colorado. PDF icon characterizing_fractures_peer2013.pdf More Documents & Publications Characterizing Fractures in the Geysers Geothermal Field by Micro-seismic Data, Using Soft Computing, Fractals,

  7. Oil recovery enhancement from fractured, low permeability reservoirs. Part 2, Annual report, October 1, 1990--September 31, 1991

    SciTech Connect (OSTI)

    Poston, S.W.

    1991-12-31

    The results of the investigative efforts for this jointly funded DOE-State of Texas research project achieved during the 1990--1991 year may be summarized as follows: Geological Characterization -- Detailed maps of the development and hierarchical nature the fracture system exhibited by Austin Chalk outcrops were prepared. These results of these efforts were directly applied to the development of production decline type curves applicable to a dual fracture-matrix flow system. Analysis of production records obtained from Austin Chalk operators illustrated the utility of these type curves to determine relative fracture/matrix contributions and extent. Well-log response in Austin Chalk wells has been shown to be a reliable indicator of organic maturity. (VSP) Vertical-Seismic Profile data was used to use shear-wave splitting concepts to estimate fracture orientations. Several programs were to be written to facilitate analysis of the data. The results of these efforts indicated fractures could be detected with VSP seismic methods. Development of the (EOR) Enhanced Oil Recovery Imbibition Process -- Laboratory displacement as well as MRI and CT imaging studies have shown the carbonated water-imbibition displacement process significantly accelerates and increases recovery of an oil saturated, low permeability core material, when compared to that of a normal brine imbibition displacement process. A study of oil recovery by the application of a cyclic carbonated water imbibition process, followed by reducing the pressure below the bubble point of the CO{sub 2}-water solution, indicated the possibility of alternate and new enhanced recovery method. The installation of an artificial solution gas drive significantly increased oil recovery. The extent and arrangement of micro-fractures in Austin Chalk horizontal cores was mapped with CT scanning techniques. The degree of interconnection of the micro-fractures was easily visualized.

  8. Seismic Velocity Structure and Depth-Dependence of Anisotropy in the Red Sea and Arabian Shield from Surface Wave Analysis

    SciTech Connect (OSTI)

    Hansen, S; Gaherty, J; Schwartz, S; Rodgers, A; Al-Amri, A

    2007-07-25

    We investigate the lithospheric and upper mantle structure as well as the depth-dependence of anisotropy along the Red Sea and beneath the Arabian Peninsula using receiver function constraints and phase velocities of surface waves traversing two transects of stations from the Saudi Arabian National Digital Seismic Network. Frequency-dependent phase delays of fundamental-mode Love and Rayleigh waves, measured using a cross-correlation procedure, require very slow shear velocities and the presence of anisotropy throughout the upper mantle. Linearized inversion of these data produce path-averaged 1D radially anisotropic models with about 4% anisotropy in the lithosphere, increasing to about 4.8% anisotropy across the lithosphere-asthenosphere boundary (LAB). Models with reasonable crustal velocities in which the mantle lithosphere is isotropic cannot satisfy the data. The lithospheric lid, which ranges in thickness from about 70 km near the Red Sea coast to about 90 km beneath the Arabian Shield, is underlain by a pronounced low-velocity zone with shear velocities as low as 4.1 km/s. Forward models, which are constructed from previously determined shear-wave splitting estimates, can reconcile surface and body wave observations of anisotropy. The low shear velocity values are similar to many other continental rift and oceanic ridge environments. These low velocities combined with the sharp velocity contrast across the LAB may indicate the presence of partial melt beneath Arabia. The anisotropic signature primarily reflects a combination of plate- and density-driven flow associated with active rifting processes in the Red Sea.

  9. A split imaging spectrometer for temporally and spatially resolved titanium absorption spectroscopy

    SciTech Connect (OSTI)

    Hager, J. D. Lanier, N. E.; Kline, J. L.; Flippo, K. A.; Bruns, H. C.; Schneider, M.; Saculla, M.; McCarville, T.

    2014-11-15

    We present a temporally and a spatially resolved spectrometer for titanium x-ray absorption spectroscopy along 2 axial symmetric lines-of-sight. Each line-of-sight of the instrument uses an elliptical crystal to acquire both the 2p and 3p Ti absorption lines on a single, time gated channel of the instrument. The 2 axial symmetric lines-of-sight allow the 2p and 3p absorption features to be measured through the same point in space using both channels of the instrument. The spatially dependent material temperature can be inferred by observing the 2p and the 3p Ti absorption features. The data are recorded on a two strip framing camera with each strip collecting data from a single line-of-sight. The design is compatible for use at both the OMEGA laser and the National Ignition Facility. The spectrometer is intended to measure the material temperature behind a Marshak wave in a radiatively driven SiO{sub 2} foam with a Ti foam tracer. In this configuration, a broad band CsI backlighter will be used for a source and the Ti absorption spectrum measured.

  10. Nucleic acid encoding a self-assembling split-fluorescent protein system

    DOE Patents [OSTI]

    Waldo, Geoffrey S.; Cabantous, Stephanie

    2015-07-14

    The invention provides a protein labeling and detection system based on self-complementing fragments of fluorescent and chromophoric proteins. The system of the invention is exemplified with various combinations of self-complementing fragments derived from Aequorea victoria Green Fluorescent Protein (GFP), which are used to detect and quantify protein solubility in multiple assay formats, both in vitro and in vivo.

  11. Nucleic acid encoding a self-assembling split-fluorescent protein system

    DOE Patents [OSTI]

    Waldo, Geoffrey S; Cabantous, Stephanie

    2014-04-01

    The invention provides a protein labeling and detection system based on self-complementing fragments of fluorescent and chromophoric proteins. The system of the invention is exemplified with various combinations of self-complementing fragments derived from Aequorea victoria Green Fluorescent Protein (GFP), which are used to detect and quantify protein solubility in multiple assay formats, both in vitro and in vivo.

  12. Arrangement for multiplexing and intensity splitting light beams for interface into fiber optic cables

    DOE Patents [OSTI]

    Johnson, Steve A.

    1990-01-01

    An arrangement especially suitable for use in a laser apparatus for converting a plurality of different input light beams, for example copper vapor laser beams, into a plurality of substantially identical light beams is disclosed herein. This arrangement utilizes an optical mixing bar which is preferably integrally formed as a single unit and which includes a main body for mixing light therein, a flat input surface on one end of the main body, and a multi-faceted output face on the opposite end of the main body. This arrangement also includes means for directing the plurality of different input light beams onto the input face of the mixing base, whereby to cause the different beams to mix within the main body of the mixing bar and exit the latter from its multi-faceted output face as the desired plurality of substantially identical output beams.

  13. Synthesis and characterization of titanium-alloyed hematite thin films for photoelectrochemical water splitting

    SciTech Connect (OSTI)

    Tang Houwen; Matin, M. A.; Wang, Heli; Deutsch, Todd; Al-Jassim, Mowafak; Turner, John; Yan, Yanfa

    2011-12-15

    We have synthesized pure and Ti-alloyed hematite thin films on F doped SnO{sub 2} coated glass substrates by radio frequency magnetron co-sputtering of iron oxide and titanium targets in mixed Ar/O{sub 2} and mixed N{sub 2}/O{sub 2} ambient. We found that the hematite films deposited in the N{sub 2}/O{sub 2} ambient exhibit much poorer crystallinity than the films deposited in the Ar/O{sub 2} ambient. We determined that Ti alloying leads to increased electron carrier concentration and crystallinity, and reduced bandgaps. Moreover, Ti-alloyed hematite thin films exhibited improved photoelectrochemical performance as compared with the pure hematite films: The photocurrents were enhanced and the photocurrent onset shifted to less positive potentials.

  14. EFFECTS OF THE NEUTRINO MASS SPLITTING ON THE NONLINEAR MATTER POWER SPECTRUM

    SciTech Connect (OSTI)

    Wagner, Christian; Verde, Licia; Jimenez, Raul [Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E08028 Barcelona (Spain)

    2012-06-20

    We have performed cosmological N-body simulations which include the effect of the masses of the individual neutrino species. The simulations were aimed at studying the effect of different neutrino hierarchies on the matter power spectrum. Compared to the linear theory predictions, we find that nonlinearities enhance the effect of hierarchy on the matter power spectrum at mildly nonlinear scales. The maximum difference between the different hierarchies is about 0.5% for a sum of neutrino masses of 0.1 eV. Albeit this is a small effect, it is potentially measurable from upcoming surveys. In combination with neutrinoless double-{beta} decay experiments, this opens up the possibility of using the sky to determine if neutrinos are Majorana or Dirac fermions.

  15. Hydrogen production by high-temperature water splitting using electron-conducting membranes

    DOE Patents [OSTI]

    Lee, Tae H.; Wang, Shuangyan; Dorris, Stephen E.; Balachandran, Uthamalingam

    2004-04-27

    A device and method for separating water into hydrogen and oxygen is disclosed. A first substantially gas impervious solid electron-conducting membrane for selectively passing hydrogen is provided and spaced from a second substantially gas impervious solid electron-conducting membrane for selectively passing oxygen. When steam is passed between the two membranes at disassociation temperatures the hydrogen from the disassociation of steam selectively and continuously passes through the first membrane and oxygen selectively and continuously passes through the second membrane, thereby continuously driving the disassociation of steam producing hydrogen and oxygen.

  16. Distributed Reforming of Renewable Liquids via Water Splitting using Oxygen Transport Membrane (OTM) (Presentation)

    Broader source: Energy.gov [DOE]

    Presented at the 2007 Bio-Derived Liquids to Hydrogen Distributed Reforming Working Group held November 6, 2007 in Laurel, Maryland.

  17. Support for Cost Analyses on Solar-Driven High Temperature Thermochemical Water-Splitting Cycles

    Broader source: Energy.gov [DOE]

    This report summarizes the application of chemical process flowsheet analyses and cash flow analyses using DOE's H2A methodology to develop near-term (2015) and longer-term (2025) cost projections for eight solar thermochemical hydrogen production reaction cycles.

  18. Retrofitting a 1960s Split-Level, Cold-Climate Home

    SciTech Connect (OSTI)

    Puttagunta, Srikanth

    2015-07-13

    National programs such as Home Performance with ENERGY STAR® and numerous other utility air-sealing programs have made homeowners aware of the benefits of energy-efficiency retrofits. Yet these programs tend to focus only on the low-hanging fruit: they recommend air sealing the thermal envelope and ductwork where accessible, switching to efficient lighting and low-flow fixtures, and improving the efficiency of mechanical systems (though insufficient funds or lack of knowledge to implement these improvements commonly prevent the implementation of these higher cost upgrades). At the other end of the spectrum, various utilities across the country are encouraging deep energy retrofit programs. Although deep energy retrofits typically seek 50% energy savings, they are often quite costly and are most applicable to gut-rehab projects. A significant potential for lowering energy use in existing homes lies between the lowhanging fruit and deep energy retrofit approaches—retrofits that save approximately 30% in energy compared to the pre-retrofit conditions. The energy-efficiency measures need to be nonintrusive so the retrofit projects can be accomplished in occupied homes.

  19. A New Method to Stabilize Solar Water-Splitting Electrodes (Fact...

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

    surface modification of high-efficiency III-V photoelectrolysis materials provides corrosion protection for hundreds of hours without sacrificing conversion efficiency....

  20. Hydrogen production by high temperature water splitting using electron conducting membranes

    DOE Patents [OSTI]

    Balachandran, Uthamalingam; Wang, Shuangyan; Dorris, Stephen E.; Lee, Tae H.

    2006-08-08

    A device and method for separating water into hydrogen and oxygen is disclosed. A first substantially gas impervious solid electron-conducting membrane for selectively passing protons or hydrogen is provided and spaced from a second substantially gas impervious solid electron-conducting membrane for selectively passing oxygen. When steam is passed between the two membranes at dissociation temperatures the hydrogen from the dissociation of steam selectively and continuously passes through the first membrane and oxygen selectively and continuously passes through the second membrane, thereby continuously driving the dissociation of steam producing hydrogen and oxygen. The oxygen is thereafter reacted with methane to produce syngas which optimally may be reacted in a water gas shift reaction to produce CO2 and H2.

  1. Nucleic acid encoding a self-assembling split-fluorescent protein system

    DOE Patents [OSTI]

    Waldo, Geoffrey S.; Cabantous, Stephanie

    2011-06-07

    The invention provides a protein labeling and detection system based on self-complementing fragments of fluorescent and chromophoric proteins. The system of the invention is exemplified with various combinations of self-complementing fragments derived from Aequorea victoria Green Fluorescent Protein (GFP), which are used to detect and quantify protein solubility in multiple assay formats, both in vitro and in vivo.

  2. WO3/TiO2 nanotube photoanodes for solar water splitting with simultaneous wastewater treatment.

    SciTech Connect (OSTI)

    Reyes, Karla Rosa; Robinson, David B.

    2013-05-01

    Nanostructured WO3/TiO2 nanotubes with properties that enhance solar photoconversion reactions were developed, characterized and tested. The TiO2 nanotubes were prepared by anodization of Ti foil, and WO3 was electrodeposited on top of the nanotubes. SEM images show that these materials have the same ordered structure as TiO2 nanotubes, with an external nanostructured WO3 layer. Diffuse reflectance spectra showed an increase in the visible absorption relative to bare TiO2 nanotubes, and in the UV absorption relative to bare WO3 films. Incident simulated solar photon-to-current efficiency increased from 30% (for bare WO3) to 50% (for WO3/TiO2 composites). With the addition of diverse organic pollutants, the photocurrent densities exhibited more than a 5-fold increase. Chemical oxygen demand measurements showed the simultaneous photodegradation of organic pollutants. The results of this work indicate that the unique structure and composition of these composite materials enhance the charge carrier transport and optical properties compared with the parent materials.

  3. New Method to Stabilize Solar Water-Splitting Electrodes (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2015-01-01

    This NREL Highlight is being produced for the 2015 February Alliance S&T Board meeting and describes a two-step modification of high-efficiency III-V photoelectrolysis materials that provide corrosion protection for hundreds of hours without sacrificing conversion efficiency.

  4. NREL Demonstrates Efficient Solar Water Splitting by Metal Oxide Photoabsorber (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-01-01

    New development demonstrates that inexpensive and robust metal oxide photoabsorbers hold great promise as photoanodes for water oxidation.

  5. Decoupling Bulk and Surface Contributions in Water- Splitting Photocatalysts by In Situ Ultrafast Spectroscopy

    SciTech Connect (OSTI)

    Appavoo, Kannatassen; Mingzhao, Liu; Black, Charles T.; Sfeir, Matthew Y.

    2015-05-10

    By performing ultrafast emission spectroscopy in an operating, bias-controlled photoelectrochemical cell, we distinguish between bulk (charge transport) and surface (chemical reaction) recombination processes in a nanostructured photocatalyst and correlate its electronic properties directly with its incident-photon-to-current efficiency.

  6. Process and apparatus for split feed of spent catalyst to high...

    Office of Scientific and Technical Information (OSTI)

    stream is charged directly to the second fluidized bed without passage through ... Country of Publication: United States Language: English Subject: 37 INORGANIC, ORGANIC, ...

  7. Dual-frequency terahertz emission from splitting filaments induced by lens tilting in air

    SciTech Connect (OSTI)

    Zhang, Zhelin; Chen, Yanping Yang, Liu; Yuan, Xiaohui; Liu, Feng; Chen, Min; Xu, Jianqiu; Zhang, Jie; Sheng, Zhengming

    2014-09-08

    Dual-frequency terahertz radiation from air-plasma filaments produced with two-color lasers in air has been demonstrated experimentally. When a focusing lens is tilted for a few degrees, it is shown that the laser filament evolves from a single one to two sub-filaments. Two independent terahertz sources emitted from the sub-filaments with different frequencies and polarizations are identified, where the frequency of terahertz waves from the trailing sub-filament is higher than that from the leading sub-filament.

  8. Building America Case Study: Retrofitting a 1960s Split-Level...

    Energy Savers [EERE]

    HERS Index: Pre-retrofit 114 Post-retrofit: * With PV 26 * Without PV 56 Validated annual energy cost savings: * With PV 4,032 * Without PV 2,199 Simple payback with ...

  9. Retrofitting a 1960s Split-Level, Cold-Climate Home

    SciTech Connect (OSTI)

    Puttagunta, Srikanth

    2015-07-01

    National programs such as Home Performance with ENERGY STAR® and numerous other utility air sealing programs have brought awareness to homeowners of the benefits of energy efficiency retrofits. Yet, these programs tend to focus on the low-hanging fruit: air-sealing the thermal envelope and ductwork where accessible, switch to efficient lighting, and low-flow fixtures. At the other end of the spectrum, deep-energy retrofit programs are also being encouraged by various utilities across the country. While deep energy retrofits typically seek 50% energy savings, they are often quite costly and most applicable to gut-rehab projects. A significant potential for lowering energy usage in existing homes lies between the low hanging fruit and deep energy retrofit approaches - retrofits that save approximately 30% in energy over the existing conditions. A key is to be non-intrusive with the efficiency measures so the retrofit projects can be accomplished in occupied homes. This cold climate retrofit project involved the design and optimization of a home in Connecticut that sought to improve energy savings by at least 30% (excluding solar PV) over the existing home's performance. This report documents the successful implementation of a cost-effective solution package that achieved performance greater than 30% over the pre-retrofit - what worked, what did not, and what improvements could be made.

  10. DOI-BLM-NV-W010-2010-0039-CX | Open Energy Information

    Open Energy Info (EERE)

    9-CX Jump to: navigation, search NEPA Document Collection for: DOI-BLM-NV-W010-2010-0039-CX CX for GeothermalExploration CX for Micro-Earthquake Survey at ?? Geothermal Area...

  11. PoroTomo_Subtask_3.1_MeqRelocations_3D_VelocityModels_30Jun2015

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

    William Foxall

    2015-06-30

    Hypocenters of local microearthquakes and 3D P- and S-velocity models computed by simultaneous inversion of arrival times recorded by the Brady seismic network Nov 2010-Mar 2015.

  12. Seismic baseline and induction studies- Roosevelt Hot Springs...

    Open Energy Info (EERE)

    magnitude one. The Roosevelt Hot Springs area has low-level seismic activity for Msub L greater than about two; however, microearthquake (Msub L less than or equal to 2)...

  13. Identification of MHF Fracture Planes and Flow Paths- a Correlation...

    Open Energy Info (EERE)

    Area (Dreesen, Et Al., 1987) Micro-Earthquake At Fenton Hill HDR Geothermal Area (Brown, 2009) Well Log Data At Fenton Hill HDR Geothermal Area (Dreesen, Et Al., 1987) Areas...

  14. PoroTomo_Subtask_3.1_MeqRelocations_3D_VelocityModels_30Jun2015

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

    William Foxall

    Hypocenters of local microearthquakes and 3D P- and S-velocity models computed by simultaneous inversion of arrival times recorded by the Brady seismic network Nov 2010-Mar 2015.

  15. State of Seismic Methods For Geothermal Reservoir Exploration...

    Office of Scientific and Technical Information (OSTI)

    ... In essence the single well method is a deep penetration well ... Eurock '94, Rock Mechanics in Petroleum Engineering, Delft, ... M. A. STARK, Microearthquakes-A Tool To Track Injected Water ...

  16. Geothermal Resource Exploration And Definition Project | Open...

    Open Energy Info (EERE)

    (Warpinski, Et Al., 2002) Ground Magnetics At Cove Fort Area (Warpinski, Et Al., 2002) Ground Magnetics At Cove Fort Area - Vapor (Warpinski, Et Al., 2002) Micro-Earthquake At...

  17. Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada...

    Open Energy Info (EERE)

    was also 15 km instead of the previously reported 40 km. Local microearthquakes cluster around 10-15 km. The geometrical block models indicate that crustal horst-graben...

  18. Latest research findings from petite sismique trials

    SciTech Connect (OSTI)

    Belesky, R.M.; Bieniawski, Z.T.; Greenfield, R.J.

    1984-01-01

    Research on a novel in-situ technique known as petite sismique is discussed. This geophysical method is capable of estimating the static deformation modules of a rock mass. The petite-sismique technique utilizes a seismic-refraction survey stressing a correlation between shear-wave frequency and the static deformation modulus. Although the technique was introduced in 1967, petite sismique has not been used extensively due to difficulties in shear-wave generation and detection. Recent developments in geophysical instrumentation provided an opportunity to evaluate better the technique in this study. With the objective of assessing the deformation modulus, field trials were conducted in coal and limestone mines. Despite attempts to develop a reliable shear-wave source, difficulties in frequency determinations persisted due to source characteristics and receiver resonance. A limited number of shear-wave-frequency observations did not confirm the originally documented relationship between shear-wave frequency and the static deformation modulus. The indicated discrepancy is attributed to differences in characteristics of the sources used in the two studies. Arising out of this research are equipment modifications and procedural recommendations which should improve the chances for success in future studies.

  19. Method and apparatus for measurement of orientation in an anisotropic medium

    DOE Patents [OSTI]

    Gilmore, Robert Snee (Burnt Hills, NY); Kline, Ronald Alan (Norman, OK); Deaton, Jr., John Broddus (Niskayuna, NY)

    1999-01-01

    A method and apparatus are provided for simultaneously measuring the anisotropic orientation and the thickness of an article. The apparatus comprises a transducer assembly which propagates longitudinal and transverse waves through the article and which receives reflections of the waves. A processor is provided to measure respective transit times of the longitudinal and shear waves propagated through the article and to calculate respective predicted transit times of the longitudinal and shear waves based on an estimated thickness, an estimated anisotropic orientation, and an elasticity of the article. The processor adjusts the estimated thickness and the estimated anisotropic orientation to reduce the difference between the measured transit times and the respective predicted transit times of the longitudinal and shear waves.

  20. Magnetically applied pressure-shear : a new technique for direct strength measurement at high pressure (final report for LDRD project 117856).

    SciTech Connect (OSTI)

    Lamppa, Derek C.; Haill, Thomas A.; Alexander, C. Scott; Asay, James Russell

    2010-09-01

    A new experimental technique to measure material shear strength at high pressures has been developed for use on magneto-hydrodynamic (MHD) drive pulsed power platforms. By applying an external static magnetic field to the sample region, the MHD drive directly induces a shear stress wave in addition to the usual longitudinal stress wave. Strength is probed by passing this shear wave through a sample material where the transmissible shear stress is limited to the sample strength. The magnitude of the transmitted shear wave is measured via a transverse VISAR system from which the sample strength is determined.

  1. Thermochemical cyclic system for splitting water and/or carbon dioxide by means of cerium compounds and reactions useful therein

    DOE Patents [OSTI]

    Bamberger, Carlos E.; Robinson, Paul R.

    1980-01-01

    A thermochemical cyclic process for producing hydrogen from water comprises reacting ceric oxide with monobasic or dibasic alkali metal phosphate to yield a solid reaction product, oxygen and water. The solid reaction product, alkali metal carbonate or bicarbonate, and water, are reacted to yield hydrogen, ceric oxide, carbon dioxide and trialkali metal phosphate. Ceric oxide is recycled. Trialkali metal phosphate, carbon dioxide and water are reacted to yield monobasic or dibasic alkali metal phosphate and alkali metal bicarbonate, which are recycled. The cylic process can be modified for producing carbon monoxide from carbon dioxide by reacting the alkali metal cerous phosphate and alkali metal carbonate or bicarbonate in the absence of water to produce carbon monoxide, ceric oxide, carbon dioxide and trialkali metal phosphate. Carbon monoxide can be converted to hydrogen by the water gas shift reaction.

  2. Thermochemical cyclic system for splitting water and/or carbon dioxide by means of cerium compounds and reactions useful therein

    DOE Patents [OSTI]

    Bamberger, C.E.; Robinson, P.R.

    A thermochemical cyclic process for producing hydrogen from water comprises reacting ceric oxide with monobasic or dibasic alkali metal phosphate to yield a solid reaction product, oxygen and water. The solid reaction product, alkali metal carbonate or bicarbonate, and water, are reacted to yield hydrogen, ceric oxide, carbon dioxide and trialkali metal phosphate. Ceric oxide is recycled. Trialkali metal phosphate, carbon dioxide and water are reacted to yield monobasic or dibasic alkali metal phosphate and alkali metal bicarbonate, which are recycled. The cyclic process can be modified for producing carbon monoxide from carbon dioxide by reacting the alkali metal cerous phosphate and alkali metal carbonate or bicarbonate in the absence of water to produce carbon monoxide, ceric oxide, carbon dioxide and trialkali metal phosphate. Carbon monoxide can be converted to hydrogen by the water gas shift reaction.

  3. Combinatorial Discovery and Optimization of the Composition, Doping and Morphology of New Oxide Semiconductors for Efficient Photoelectrochemical Water Splitting

    SciTech Connect (OSTI)

    Parkinson, Bruce A.; Jianghua, He

    2015-01-06

    The increasing need for carbon free energy has focused renewed attention on solar energy conversion. Although photovoltaic cells excel at directly converting of solar energy to electricity, they do not directly produce stored energy or fuels that account for more than 75% of current energy use. Direct photoelectrolysis of water has the advantage of converting solar energy directly to hydrogen, an ideal non-carbon and nonpolluting energy carrier, by replacing both a photovoltaic array and an electrolysis unit with one potentially inexpensive device. Unfortunately no materials are currently known to efficiently photoelectrolyze water that are, efficient, inexpensive and stable under illumination in electrolytes for many years. Nanostructured semiconducting metal oxides could potentially fulfill these requirements, making them the most promising materials for solar water photoelectrolysis, however no oxide semiconductor has yet been discovered with all the required properties. We have developed a simple, high-throughput combinatorial approach to prepare and screen many multi component metal oxides for water photoelectrolysis activity. The approach uses ink jet printing of overlapping patterns of soluble metal oxide precursors onto conductive glass substrates. Subsequent pyrolysis produces metal oxide phases that are screened for photoelectrolysis activity by measuring photocurrents produced by scanning a laser over the printed patterns in aqueous electrolytes. Several promising and unexpected compositions have been identified.

  4. Striving toward noble-metal-free photocatalytic water splitting: The hydrogenated-graphene-TiO2 prototype

    SciTech Connect (OSTI)

    Nguyen-Phan, Thuy -Duong; Luo, Si; Liu, Zongyuan; Gamalski, Andrew D.; Tao, Jing; Xu, Wenqian; Stach, Eric A.; Polyansky, Dmitry E.; Senanayake, Sanjaya D.; Fujita, Etsuko; Rodriguez, Jose A.

    2015-08-20

    Graphane, graphone and hydrogenated graphene (HG) have been extensively studied in recent years due to their interesting properties and potential use in commercial and industrial applications. The present study reports investigation of hydrogenated graphene/TiO2-x (HGT) nanocomposites as photocatalysts for H2 and O2 production from water without the assistance of a noble metal co-catalyst. By combination of several techniques, the morphologies, bulk/atomic structure and electronic properties of all the powders were exhaustively interrogated. Hydrogenation treatment efficiently reduces TiO2 nanoparticles, while the graphene oxide sheets undergo the topotactic transformation from a graphene-like structure to a mixture of graphitic and turbostratic carbon (amorphous/disordered) upon altering the calcination atmosphere from a mildly reducing to a H2-abundant environment. Remarkably, the hydrogenated graphene-TiO2-x composite that results upon H2-rich reduction exhibits the highest photocatalytic H2 evolution performance equivalent to low loading of Pt (~0.12 wt%), whereas the addition of HG suppresses the O2 production. As a result, we propose that such an enhancement can be attributed to a combination of factors including the introduction of oxygen vacancies and Ti3+ states, retarding the recombination of charge carriers and thus, facilitating the charge transfer from TiO2-x to the carbonaceous sheet.

  5. Design of Semiconducting Tetrahedral Mn 1 ₋ x Zn x O Alloys and Their Application to Solar Water Splitting

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

    Peng, Haowei; Ndione, Paul F.; Ginley, David S.; Zakutayev, Andriy; Lany, Stephan

    2015-05-18

    Transition metal oxides play important roles as contact and electrode materials, but their use as active layers in solar energy conversion requires achieving semiconducting properties akin to those of conventional semiconductors like Si or GaAs. In particular, efficient bipolar carrier transport is a challenge in these materials. Based on the prediction that a tetrahedral polymorph of MnO should have such desirable semiconducting properties, and the possibility to overcome thermodynamic solubility limits by nonequilibrium thin-film growth, we exploit both structure-property and composition-structure relationships to design and realize novel wurtzite-structure Mn₁₋xZnxO alloys. At Zn compositions above x ≈ 0.3, thin films ofmore » these alloys assume the tetrahedral wurtzite structure instead of the octahedral rocksalt structure of MnO, thereby enabling semiconductor properties that are unique among transition metal oxides, i.e., a band gap within the visible spectrum, a band-transport mechanism for both electron and hole carriers, electron doping, and a band lineup suitable for solar hydrogen generation. A proof of principle is provided by initial photo-electrocatalytic device measurements, corroborating, in particular, the predicted favorable hole-transport properties of these alloys.« less

  6. Striving toward noble-metal-free photocatalytic water splitting: The hydrogenated-graphene-TiO2 prototype

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

    Nguyen-Phan, Thuy -Duong; Luo, Si; Liu, Zongyuan; Gamalski, Andrew D.; Tao, Jing; Xu, Wenqian; Stach, Eric A.; Polyansky, Dmitry E.; Senanayake, Sanjaya D.; Fujita, Etsuko; et al

    2015-08-20

    Graphane, graphone and hydrogenated graphene (HG) have been extensively studied in recent years due to their interesting properties and potential use in commercial and industrial applications. The present study reports investigation of hydrogenated graphene/TiO2-x (HGT) nanocomposites as photocatalysts for H2 and O2 production from water without the assistance of a noble metal co-catalyst. By combination of several techniques, the morphologies, bulk/atomic structure and electronic properties of all the powders were exhaustively interrogated. Hydrogenation treatment efficiently reduces TiO2 nanoparticles, while the graphene oxide sheets undergo the topotactic transformation from a graphene-like structure to a mixture of graphitic and turbostratic carbon (amorphous/disordered)more » upon altering the calcination atmosphere from a mildly reducing to a H2-abundant environment. Remarkably, the hydrogenated graphene-TiO2-x composite that results upon H2-rich reduction exhibits the highest photocatalytic H2 evolution performance equivalent to low loading of Pt (~0.12 wt%), whereas the addition of HG suppresses the O2 production. As a result, we propose that such an enhancement can be attributed to a combination of factors including the introduction of oxygen vacancies and Ti3+ states, retarding the recombination of charge carriers and thus, facilitating the charge transfer from TiO2-x to the carbonaceous sheet.« less

  7. Building America Webinar: High Performance Space Conditioning Systems, Part I: Heating and Cooling with Mini-Splits in the Northeast

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the U.S. Department of Energy Building America webinar, High Performance Space Conditioning Systems, Part I, conducted on October 23, 2014, by Kohta Ueno of Building Science Corporation.

  8. Existing Whole-House Solutions Case Study: Retrofitting a 1960s Split-Level Cold-Climate Home

    SciTech Connect (OSTI)

    S. Puttagunta

    2015-08-01

    ​​National programs such as Home Performance with ENERGY STAR® and numerous other utility air sealing programs have brought awareness to homeowners of the benefits of energy efficiency retrofits. Yet, these programs tend to focus on the low-hanging fruit: air-sealing the thermal envelope and ductwork where accessible, switch to efficient lighting, and low-flow fixtures. At the other end of the spectrum, deep-energy retrofit programs are also being encouraged by various utilities across the country. While deep energy retrofits typically seek 50% energy savings, they are often quite costly and most applicable to gut-rehab projects. A significant potential for lowering energy usage in existing homes lies between the low hanging fruit and deep energy retrofit approaches - retrofits that save approximately 30% in energy over the existing conditions.

  9. CX-004284: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Recovery Act: Conducting a 3-Dimensional Converted Shear Wave ProjectCX(s) Applied: A9, B3.1, B3.7Date: 10/18/2010Location(s): Imperial County, CaliforniaOffice(s): Energy Efficiency and Renewable Energy, Golden Field Office

  10. Anisotropic determination and correction for ultrasonic flaw detection by spectral analysis

    DOE Patents [OSTI]

    Adler, Laszlo; Von Cook, K.; Simpson, Jr., William A.; Lewis, D. Kent

    1978-01-01

    The anisotropic nature of a material is determined by measuring the velocity of an ultrasonic longitudinal wave and a pair of perpendicular ultrasonic shear waves through a sample of the material each at a plurality of different angles in three planes orthogonal to each other. The determined anisotropic nature is used as a correction factor in a spectral analyzing system of flaw determination.

  11. CX-001057: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Characterizing Fractures in Geyser's Geothermal Field by Micro-Seismic Data, Using Soft Computing, Fractals, and Shear Wave AnisotropyCX(s) Applied: A9Date: 03/10/2010Location(s): CaliforniaOffice(s): Energy Efficiency and Renewable Energy, Golden Field Office

  12. WE-E-9A-01: Ultrasound Elasticity

    SciTech Connect (OSTI)

    Emelianov, S; Hall, T; Bouchard, R

    2014-06-15

    Principles and techniques of ultrasound-based elasticity imaging will be presented, including quasistatic strain imaging, shear wave elasticity imaging, and their implementations in available systems. Deeper exploration of quasistatic methods, including elastic relaxation, and their applications, advantages, artifacts and limitations will be discussed. Transient elastography based on progressive and standing shear waves will be explained in more depth, along with applications, advantages, artifacts and limitations, as will measurement of complex elastic moduli. Comparisons will be made between ultrasound radiation force techniques, MR elastography, and the simple A mode plus mechanical plunger technique. Progress in efforts, such as that by the Quantitative Imaging Biomarkers Alliance, to reduce the differences in the elastic modulus reported by different commercial systems will be explained. Dr. Hall is on an Advisory Board for Siemens Ultrasound and has a research collaboration with them, including joint funding by R01CA140271 for nonlinear elasticity imaging. Learning Objectives: Be reminded of the long history of palpation of tissue elasticity for critical medical diagnosis and the relatively recent advances to be able to image tissue strain in response to an applied force. Understand the differences between shear wave speed elasticity measurement and imaging and understand the factors affecting measurement and image frame repletion rates. Understand shear wave propagation effects that can affect measurements, such as essentially lack of propagation in fluids and boundary effects, so important in thin layers. Know characteristics of available elasticity imaging phantoms, their uses and limitations. Understand thermal and cavitational limitations affecting radiation force-based shear wave imaging. Have learning and references adequate to for you to use in teaching elasticity imaging to residents and technologists. Be able to explain how elasticity measurement and imaging can contribute to diagnosis of breast and prostate cancer, staging of liver fibrosis, age estimation of deep veinous fhrombosis, confirmation of thermal lesions in the liver after RF ablation.

  13. Improved Microseismicity Detection During Newberry EGS Stimulations

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

    Templeton, Dennise

    Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return.

  14. Integration of Noise and Coda Correlation Data into Kinematic and Waveform Inversions

    Broader source: Energy.gov [DOE]

    This project will focus on using microearthquakes (MEQ) and noise correlation Green's functions (NCF) obtained from MEQs and ambient noise and coda-wave interferometry to image the physical properties of geothermal reservoirs and detect and map changes in reservoir properties with time.

  15. CX-002364: Categorical Exclusion Determination

    Office of Energy Efficiency and Renewable Energy (EERE)

    Development of a Geological and Geomechanical Framework for the Analysis of Micro-Earthquakes in Enhanced Geothermal System ExperimentsCX(s) Applied: B3.6, A9Date: 05/11/2010Location(s): TexasOffice(s): Energy Efficiency and Renewable Energy, Golden Field Office

  16. Improved Microseismicity Detection During Newberry EGS Stimulations

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

    Templeton, Dennise

    2013-10-01

    Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return.

  17. Improved Microseismicity Detection During Newberry EGS Stimulations

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

    Templeton, Dennise

    2013-11-01

    Effective enhanced geothermal systems (EGS) require optimal fracture networks for efficient heat transfer between hot rock and fluid. Microseismic mapping is a key tool used to infer the subsurface fracture geometry. Traditional earthquake detection and location techniques are often employed to identify microearthquakes in geothermal regions. However, most commonly used algorithms may miss events if the seismic signal of an earthquake is small relative to the background noise level or if a microearthquake occurs within the coda of a larger event. Consequently, we have developed a set of algorithms that provide improved microearthquake detection. Our objective is to investigate the microseismicity at the DOE Newberry EGS site to better image the active regions of the underground fracture network during and immediately after the EGS stimulation. Detection of more microearthquakes during EGS stimulations will allow for better seismic delineation of the active regions of the underground fracture system. This improved knowledge of the reservoir network will improve our understanding of subsurface conditions, and allow improvement of the stimulation strategy that will optimize heat extraction and maximize economic return.

  18. Seismic sources

    DOE Patents [OSTI]

    Green, M.A.; Cook, N.G.W.; McEvilly, T.V.; Majer, E.L.; Witherspoon, P.A.

    1987-04-20

    Apparatus is described for placement in a borehole in the earth, which enables the generation of closely controlled seismic waves from the borehole. Pure torsional shear waves are generated by an apparatus which includes a stator element fixed to the borehole walls and a rotor element which is electrically driven to rapidly oscillate on the stator element to cause reaction forces transmitted through the borehole walls to the surrounding earth. Longitudinal shear waves are generated by an armature that is driven to rapidly oscillate along the axis of the borehole, to cause reaction forces transmitted to the surrounding earth. Pressure waves are generated by electrically driving pistons that press against opposite ends of a hydraulic reservoir that fills the borehole. High power is generated by energizing the elements for more than about one minute. 9 figs.

  19. DYNA3D Non-reflecting Boundary Conditions - Test Problems

    SciTech Connect (OSTI)

    Zywicz, E

    2006-09-28

    Two verification problems were developed to test non-reflecting boundary segments in DYNA3D (Whirley and Engelmann, 1993). The problems simulate 1-D wave propagation in a semi-infinite rod using a finite length rod and non-reflecting boundary conditions. One problem examines pure pressure wave propagation, and the other problem explores pure shear wave propagation. In both problems the non-reflecting boundary segments yield results that differ only slightly (less than 6%) during a short duration from their corresponding theoretical solutions. The errors appear to be due to the inability to generate a true step-function compressive wave in the pressure wave propagation problem and due to segment integration inaccuracies in the shear wave propagation problem. These problems serve as verification problems and as regression test problems for DYNA3D.

  20. Down hole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, Harry C.; Hills, Richard G.; Striker, Richard P.

    1989-01-01

    A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  1. Fluid driven torsional dipole seismic source

    DOE Patents [OSTI]

    Hardee, Harry C.

    1991-01-01

    A compressible fluid powered oscillating downhole seismic source device capable of periodically generating uncontaminated horizontally-propagated, shear waves is provided. A compressible fluid generated oscillation is created within the device which imparts an oscillation to a housing when the device is installed in a housing such as the cylinder off an existing downhole tool, thereby a torsional seismic source is established. Horizontal waves are transferred to the surrounding bore hole medium through downhole clamping.

  2. Advanced downhole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, Harry C.; Hills, Richard G.; Striker, Richard P.

    1991-07-16

    An advanced downhole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  3. SASW Measurements at Hanford

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

    H - Spectral Analysis of Surface Waves Hanford Site-Wide Probabilistic Seismic Hazard Analysis (PSHA): Seismic Shear Wave Velocity Profiling at Hanford, WA SASW Testing and Analysis Procedures, V s Profiles, Sensitivity Studies and Responses to Technical Integration Team Questions for Pacific Northwest National Laboratory Richland, WA by Kenneth H. Stokoe, II Yin-Cheng Lin Sungmoon Hwang, and Julia Roberts May 7, 2014 Geotechnical Engineering Report GR14-1 Geotechnical Engineering Center Civil

  4. Method for FractMethod for Fracture Detection Using Multicomponent Seismic

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

    Dataure Detection Using Multicomponent Seismic Data - Energy Innovation Portal Method for FractMethod for Fracture Detection Using Multicomponent Seismic Dataure Detection Using Multicomponent Seismic Data Dr. Bryan DeVault Department of Geophysics Colorado School of Mines Contact CSM About This Technology Technology Marketing SummaryThis invention provides a method for detecting fractures in the subsurface of the earth's crust by using seismic shear waves. DescriptionAdditionally, it can be

  5. NREL Demonstrates Efficient Solar Water Splitting by Metal Oxide Photoabsorber (Fact Sheet), NREL Highlights in Science, NREL (National Renewable Energy Laboratory)

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

    New development demonstrates that inexpensive and robust metal oxide photoabsorbers hold great promise as photoanodes for water oxidation. The production of solar fuels (e.g., H 2 from H 2 O, hydrocarbons from CO 2 ) via direct photoelectrochemical reactions is a promising approach in the pursuit of renewable energy sources. Production of O 2 is the only scalable and renewable oxidation that can balance these fuel-forming reduction reactions. However, few materials have the necessary properties

  6. Strong spin-orbit coupling and Zeeman spin splitting in angle dependent magnetoresistance of Bi{sub 2}Te{sub 3}

    SciTech Connect (OSTI)

    Dey, Rik Pramanik, Tanmoy; Roy, Anupam; Rai, Amritesh; Guchhait, Samaresh; Sonde, Sushant; Movva, Hema C. P.; Register, Leonard F.; Banerjee, Sanjay K.; Colombo, Luigi

    2014-06-02

    We have studied angle dependent magnetoresistance of Bi{sub 2}Te{sub 3} thin film with field up to 9 T over 2–20 K temperatures. The perpendicular field magnetoresistance has been explained by the Hikami-Larkin-Nagaoka theory alone in a system with strong spin-orbit coupling, from which we have estimated the mean free path, the phase coherence length, and the spin-orbit relaxation time. We have obtained the out-of-plane spin-orbit relaxation time to be small and the in-plane spin-orbit relaxation time to be comparable to the momentum relaxation time. The estimation of these charge and spin transport parameters are useful for spintronics applications. For parallel field magnetoresistance, we have confirmed the presence of Zeeman effect which is otherwise suppressed in perpendicular field magnetoresistance due to strong spin-orbit coupling. The parallel field data have been explained using both the contributions from the Maekawa-Fukuyama localization theory for non-interacting electrons and Lee-Ramakrishnan theory of electron-electron interactions. The estimated Zeeman g-factor and the strength of Coulomb screening parameter agree well with the theory. Finally, the anisotropy in magnetoresistance with respect to angle has been described by the Hikami-Larkin-Nagaoka theory. This anisotropy can be used in anisotropic magnetic sensor applications.

  7. Materials for light-induced water splitting: In situ controlled surface preparation of GaPN epilayers grown lattice-matched on Si(100)

    SciTech Connect (OSTI)

    Supplie, Oliver; May, Matthias M.; Stange, Helena; Hhn, Christian; Lewerenz, Hans-Joachim; Hannappel, Thomas

    2014-03-21

    Energy storage is a key challenge in solar-driven renewable energy conversion. We promote a photochemical diode based on dilute nitride GaPN grown lattice-matched on Si(100), which could reach both high photovoltaic efficiencies and evolve hydrogen directly without external bias. Homoepitaxial GaP(100) surface preparation was shown to have a significant impact on the semiconductor-water interface formation. Here, we grow a thin, pseudomorphic GaP nucleation buffer on almost single-domain Si(100) prior to GaPN growth and compare the GaP{sub 0.98}N{sub 0.02}/Si(100) surface preparation to established P- and Ga-rich surfaces of GaP/Si(100). We apply reflection anisotropy spectroscopy to study the surface preparation of GaP{sub 0.98}N{sub 0.02} in situ in vapor phase epitaxy ambient and benchmark the signals to low energy electron diffraction, photoelectron spectroscopy, and x-ray diffraction. While the preparation of the Ga-rich surface is hardly influenced by the presence of the nitrogen precursor 1,1-dimethylhydrazine (UDMH), we find that stabilization with UDMH after growth hinders well-defined formation of the V-rich GaP{sub 0.98}N{sub 0.02}/Si(100) surface. Additional features in the reflection anisotropy spectra are suggested to be related to nitrogen incorporation in the GaP bulk.

  8. Synergetic effects of II-VI sensitization upon TiO{sub 2} for photoelectrochemical water splitting; a tri-layered structured scheme

    SciTech Connect (OSTI)

    Mumtaz, Asad; Mohamed, Norani Muti

    2014-10-24

    World's energy demands are growing on a higher scale increasing the need of more reliable and long term renewable energy resources. Efficient photo-electrochemical (PEC) devices based on novel nano-structured designs for solar-hydrogen generation need to be developed. This study provides an insight of the tri-layered-TiO2 based nanostructures. Observing the mechanism of hydrogen production, the comparison of the structural order during the synthesis is pronounced. The sequence in the tri-layered structure affects the photogenerated electron (e{sup −}) and hole (h{sup +}) pair transfer and separation. It is also discussed that not only the semiconductors band gaps alignment is important with respect to the water redox potential but also the interfacial regions. Quasi-Fermi-level adjustment at the interfacial regions plays a key role in deciding the solar to hydrogen efficiency. More efficient multicomponent semiconductor nano-design (MCSN) could be developed with the approach given in this study.

  9. Design of Semiconducting Tetrahedral Mn1-xZnxO Alloys and Their Application to Solar Water Splitting

    SciTech Connect (OSTI)

    Peng, Haowei; Ndione, Paul F.; Ginley, David S.; Zakutayev, A.; Lany, Stephen

    2015-05-18

    Both structure-property and composition-structure relationships are exploited to design and realize novel wurtzite-structure Mn1-xZnxO alloys. A proof of principle is provided that corroborates, in particular, the predicted favorable hole-transport properties of these alloys.

  10. Level crossings and zero-field splitting in the {Cr8}-cubane spin-cluster studied using inelastic neutron scattering and magnetization

    SciTech Connect (OSTI)

    Vaknin, D.; Garlea, Vasile O; Demmel, F.; Mamontov, Eugene; Nojiri, H; Martin, Catalin; Chiorescu, Irinel; Qiu, Y.; Luban, M.; Kogerler, P.; Fielden, J.; Engelhardt, L; Rainey, C

    2010-01-01

    Inelastic neutron scattering (INS) in variable magnetic field and high-field magnetization measurements in the millikelvin temperature range were performed to gain insight into the low-energy magnetic excitation spectrum and the field-induced level crossings in the molecular spin cluster {Cr8}-cubane. These complementary techniques provide consistent estimates of the lowest level-crossing field. The overall features of the experimental data are explained using an isotropic Heisenberg model, based on three distinct exchange interactions linking the eight CrIII paramagnetic centers (spins s = 3/2), that is supplemented with a relatively large molecular magnetic anisotropy term for the lowest S = 1 multiplet. It is noted that the existence of the anisotropy is clearly evident from the magnetic field dependence of the excitations in the INS measurements, while the magnetization measurements are not sensitive to its effects.

  11. Magnetorotational Instability: Nonmodal Growth and the Relationship of Global Modes to the Shearing Box

    SciTech Connect (OSTI)

    J Squire, A Bhattacharjee

    2014-07-01

    We study the magnetorotational instability (MRI) (Balbus & Hawley 1998) using non-modal stability techniques.Despite the spectral instability of many forms of the MRI, this proves to be a natural method of analysis that is well-suited to deal with the non-self-adjoint nature of the linear MRI equations. We find that the fastest growing linear MRI structures on both local and global domains can look very diff#11;erent to the eigenmodes, invariably resembling waves shearing with the background flow (shear waves). In addition, such structures can grow many times faster than the least stable eigenmode over long time periods, and be localized in a completely di#11;fferent region of space. These ideas lead for both axisymmetric and non-axisymmetric modes to a natural connection between the global MRI and the local shearing box approximation. By illustrating that the fastest growing global structure is well described by the ordinary diff#11;erential equations (ODEs) governing a single shear wave, we find that the shearing box is a very sensible approximation for the linear MRI, contrary to many previous claims. Since the shear wave ODEs are most naturally understood using non-modal analysis techniques, we conclude by analyzing local MRI growth over finite time-scales using these methods. The strong growth over a wide range of wave-numbers suggests that non-modal linear physics could be of fundamental importance in MRI turbulence (Squire & Bhattacharjee 2014).

  12. Light-Material Interactions in Energy Conversion - Energy Frontier...

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

    Mikayla Anderson is a graduate student in the Nuzzo group working on spectrum splitting in ... She studies frequency splitting optics for ultrahigh efficiency spectrum-splitting solar ...

  13. Geopressured-geothermal well activities in Louisiana

    SciTech Connect (OSTI)

    John, C.J.

    1992-10-01

    Since September 1978, microseismic networks have operated continuously around US Department of Energy (DOE) geopressured-geothermal well sites to monitor any microearthquake activity in the well vicinity. Microseismic monitoring is necessary before flow testing at a well site to establish the level of local background seismicity. Once flow testing has begun, well development may affect ground elevations and/or may activate growth faults, which are characteristic of the coastal region of southern Louisiana and southeastern Texas where these geopressured-geothermal wells are located. The microseismic networks are designed to detest small-scale local earthquakes indicative of such fault activation. Even after flow testing has ceased, monitoring continues to assess any microearthquake activity delayed by the time dependence of stress migration within the earth. Current monitoring shows no microseismicity in the geopressured-geothermal prospect areas before, during, or after flow testing.

  14. Geopressured-geothermal well activities in Louisiana. Annual report, 1 January 1991--31 December 1991

    SciTech Connect (OSTI)

    John, C.J.

    1992-10-01

    Since September 1978, microseismic networks have operated continuously around US Department of Energy (DOE) geopressured-geothermal well sites to monitor any microearthquake activity in the well vicinity. Microseismic monitoring is necessary before flow testing at a well site to establish the level of local background seismicity. Once flow testing has begun, well development may affect ground elevations and/or may activate growth faults, which are characteristic of the coastal region of southern Louisiana and southeastern Texas where these geopressured-geothermal wells are located. The microseismic networks are designed to detest small-scale local earthquakes indicative of such fault activation. Even after flow testing has ceased, monitoring continues to assess any microearthquake activity delayed by the time dependence of stress migration within the earth. Current monitoring shows no microseismicity in the geopressured-geothermal prospect areas before, during, or after flow testing.

  15. Self-Assessment Standard for DOE Contractor Criticality Safety Programs

    Energy Savers [EERE]

    Seismicity Protocol Seismicity Protocol Project objectives: Develop an updated protocol/best engineering practices to address public and industry issues associated with induced seismicity. PDF icon seismic_majer_induced_protocol.pdf More Documents & Publications Development of an Updated Induced Seismicity Protocol for the Application of Microearthquake (MEQ) Monitoring for Characterizing Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report Monitoring the Effect

  16. Application of seismic tomographic techniques in the investigation of geothermal systems

    SciTech Connect (OSTI)

    Romero, A.E. Jr.

    1995-05-01

    The utility of microearthquake data for characterizing the Northwest Geysers geothermal field and the Long Valley Caldera (LVC) was investigated. Three-dimensional (3-D) P- and S-wave seismic velocity models were estimated for the Coldwater Creek Steam Field (CCSF) in the Northwest Geysers region. Hypocenters relocated using these 3-D models appear to be associated with the steam producing zone, with a deeper cluster of hypocenters beneath an active injection well. Spatial and temporal patterns of seismicity exhibit strong correlation with geothermal exploitation. A 3-D differential attenuation model was also developed for the CCSF from spectral ratios corrected for strong site effects. High-velocity anomalies and low attenuation in the near surface correspond to Franciscan metagraywacke and greenstone units. Microearthquakes recorded at seismographic stations located near the metagraywacke unit exhibit high corner frequencies. Low-velocity anomalies and higher attenuation in the near surface are associated with sections of Franciscan melange. Near-surface high attenuation and high Vp/Vs are interpreted to indicate liquid-saturated regions affected by meteoric recharge. High attenuation and low Vp/Vs marks the steam producing zone, suggesting undersaturation of the reservoir rocks. The extent of the high attenuation and low Vp/Vs anomalies suggest that the CCSF steam reservoir may extend northwestward beyond the known producing zone. This study concludes that microearthquake monitoring may be useful as an active reservoir management tool. Seismic velocity and attenuation structures as well as the distribution of microearthquake activity can be used to identify and delineate the geothermal reservoir, while temporal variations in these quantities would be useful in tracking changes during exploitation.

  17. Self-Assessment for Level I Certification Applicants | Department of Energy

    Office of Environmental Management (EM)

    Seismicity Protocol Seismicity Protocol Project objectives: Develop an updated protocol/best engineering practices to address public and industry issues associated with induced seismicity. PDF icon seismic_majer_induced_protocol.pdf More Documents & Publications Development of an Updated Induced Seismicity Protocol for the Application of Microearthquake (MEQ) Monitoring for Characterizing Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report Monitoring the Effect

  18. Development of high-capacity cathode materials with integrated structures |

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

    of Microearthquake (MEQ) Monitoring for Characterizing Enhanced Geothermal Systems; 2010 Geothermal Technology Program Peer Review Report | Department of Energy DOE 2010 Geothermal Technologies Program Peer Review PDF icon seismic_024_majer.pdf More Documents & Publications Microseismic Study with LBNL - Monitoring the Effect of Injection of Fluids from the Lake County Pipeline on Seismicity at The Geysers, California, Geothermal Field; 2010 Geothermal Technology Program Peer Review

  19. Full Reviews: Seismicity and Seismic | Department of Energy

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

    Seismicity and Seismic. Microearthquake Technology for EGS Fracture Characterization Gillian R. Foulger and Bruce R. Julian, Foulger Consulting Project Presentation | Peer Reviewer Comments Seismic Fracture Characterization Methods for Enhanced Geothermal Systems John H. Queen, Hi-Q Geophysical Inc. Project Presentation | Peer Reviewer Comments Monitoring the Effect of Injection of Fluids from the Lake County Pipeline on Seismicity at The Geysers, California Geothermal Field Ernest L. Majer,

  20. INL Seismic Monitoring Annual Report: January 1, 2010 – December 31, 2010

    SciTech Connect (OSTI)

    N. Seth Carpenter; Suzette J. Payne; Jed M. Hodges; Robert G. Berg

    2011-09-01

    During 2010, the INL Seismic Monitoring Program evaluated 11,606 earthquakes from around the world, the western United States, and local region of the eastern Snake River Plain (ESRP). INL located 2,085 earthquakes and man-made blasts within the local region outside and within a 161-km (or 100-mile) radius of INL. Of these events, 53 were small-to-moderate size earthquakes ranging in magnitude from 3.0 to 4.8. 672 earthquakes occurred within the 161-km radius of INL and the majority of these earthquakes were located in active regions of the Basin and Range Province that surrounds the ESRP. There were 10 microearthquakes within the boundary of the ESRP, all of magnitude less than or equal to 2.0. Five of those were located within and near the ESRP at Craters of the Moon National Monument (COM) at mid- and lower-crust depths and are interpreted to be related to fluid movement. Since 1972, INL has recorded 48 small-magnitude, microearthquakes (M = 2.2) within the ESRP (not including COM events) and 22 deep microearthquakes (M = 2.3) in the vicinity of Craters of the Moon National Monument.

  1. INL Seismic Monitoring Annual Report: January 1, 2011 - December 31, 2011

    SciTech Connect (OSTI)

    S. J. Payne; J. M. Hodges; R. G. Berg; D. F. Bruhn

    2012-12-01

    During 2011, the Idaho National Laboratory Seismic Monitoring Program evaluated 21,928 independent triggers that included earthquakes from around the world, the western United States, and local region of the Snake River Plain. Seismologists located 2,063 earthquakes and man-made blasts within and near the 161-km (or 100-mile) radius of the Idaho National Laboratory. Of these events, 16 were small-to-moderate size earthquakes ranging in magnitude (M) from 3.0 to 4.4. Within the 161-km radius, the majority of 941 earthquakes (M < 4.4) occurred in the active regions of the Basin and Range Province with only six microearthquakes occurring in the Snake River Plain. In the northern and southeastern Basin and Range, eight earthquake swarms occurred and included over 325 events. Five of the Snake River Plain earthquakes were located within and near the northern and southern ends of the Great Rift volcanic rift zone. All have anomalously deep focal depths (16 to 38 km) and waveforms indicative of fluid movement at mid- and lower-crustal levels and are a continuation of activity observed at Craters of the Moon National Monument since 2007. Since 1972, the Idaho National Laboratory has recorded 55 small-magnitude microearthquakes (M = 2.2) within the eastern Snake River Plain and 25 deep microearthquakes (M = 2.3) in the vicinity of Craters of the Moon National Monument.

  2. NEAR FIELD MODELING OF SPE1 EXPERIMENT AND PREDICTION OF THE SECOND SOURCE

    Office of Scientific and Technical Information (OSTI)

    PHYSICS EXPERIMENTS (SPE2) (Technical Report) | SciTech Connect NEAR FIELD MODELING OF SPE1 EXPERIMENT AND PREDICTION OF THE SECOND SOURCE PHYSICS EXPERIMENTS (SPE2) Citation Details In-Document Search Title: NEAR FIELD MODELING OF SPE1 EXPERIMENT AND PREDICTION OF THE SECOND SOURCE PHYSICS EXPERIMENTS (SPE2) Motion along joints and fractures in the rock has been proposed as one of the sources of near-source shear wave generation, and demonstrating the validity of this hypothesis is a focal

  3. A summary report on the search for current technologies and developers to develop depth profiling/physical parameter end effectors

    SciTech Connect (OSTI)

    Nguyen, Q.H.

    1994-09-12

    This report documents the search strategies and results for available technologies and developers to develop tank waste depth profiling/physical parameter sensors. Sources searched include worldwide research reports, technical papers, journals, private industries, and work at Westinghouse Hanford Company (WHC) at Richland site. Tank waste physical parameters of interest are: abrasiveness, compressive strength, corrosiveness, density, pH, particle size/shape, porosity, radiation, settling velocity, shear strength, shear wave velocity, tensile strength, temperature, viscosity, and viscoelasticity. A list of related articles or sources for each physical parameters is provided.

  4. Method for measuring liquid viscosity and ultrasonic viscometer

    DOE Patents [OSTI]

    Sheen, Shuh-Haw; Lawrence, William P.; Chien, Hual-Te; Raptis, Apostolos C.

    1994-01-01

    An ultrasonic viscometer and method for measuring fluid viscosity are provided. Ultrasonic shear and longitudinal waves are generated and coupled to the fluid. Reflections from the generated ultrasonic shear and longitudinal waves are detected. Phase velocity of the fluid is determined responsive to the detected ultrasonic longitudinal waves reflections. Viscosity of the fluid is determined responsive to the detected ultrasonic shear waves reflections. Unique features of the ultrasonic viscometer include the use of a two-interface fluid and air transducer wedge to measure relative signal change and to enable self calibration and the use of a ratio of reflection coefficients for two different frequencies to compensate for environmental changes, such as temperature.

  5. DE-AI26-06NT42878 - Bottom Source Task | netl.doe.gov

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

    Bottom Source Task Gas Hydrate Research in Deep Sea Sediments DE-AI26-06NT42878 - Bottom Source Task Last Reviewed 11/7/2011 Project Goal The objective of this project is to develop and test a bottom-mounted seismic source for mapping gas hydrates in marine environments. The Naval Research Laboratory (NRL) will modify their existing Helmholtz resonator seismic source, which generates both compressional and shear waves, and develop a system for mounting it onto the seafloor. The resulting

  6. Ground motion characterization of the single shot in a mining blast array with the close-in seismic data

    SciTech Connect (OSTI)

    Yang, Xiaoning; Stump, B.W.

    1995-04-01

    Ground motion data from single, cylindrical explosions with the same source configuration as the individual explosions that make up a production mining blast array are analyzed. Strong shear motion is observed which can not be accounted for by the simple explosion source. Spall (the detachment and slap-down of the near surface strata and the separation of the burden and overburden from the continuum) accompanying the explosion seems to play an important role in shear wave energy generation. These shear energy may be the most damaging to the structures near the production site.

  7. Deep Downhole Seismic Testing for Earthquake Engineering Studies

    SciTech Connect (OSTI)

    Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh; Rohay, Alan C.

    2008-10-17

    Downhole seismic testing is one field test that is commonly used to determine compression-wave (P) and shear-wave (S) velocity profiles in geotechnical earthquake engineering investigations. These profiles are required input in evaluations of the responses to earthquake shaking of geotechnical sites and structures at these sites. In the past, traditional downhole testing has generally involved profiling in the 30- to 150-m depth range. As the number of field seismic investigations at locations with critical facilities has increased, profiling depths have also increased. An improved downhole test that can be used for wave velocity profiling to depths of 300 to 600 m or more is presented.

  8. Down-hole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, H.C.; Hills, R.G.; Striker, R.P.

    1982-10-28

    A down hole periodic seismic generator system is disclosed for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  9. Photocatalytic splitting of water under visible-light irradiation over the NiOx-loaded Sm{sub 2}InTaO{sub 7} with 4f-d{sup 10}-d{sup 0} configuration

    SciTech Connect (OSTI)

    Tang Xinde; Ye Hongqi; Liu Hui; Ma Chenxia; Zhao Zhi

    2010-01-15

    A new visible-light-response photocatalyst Sm{sub 2}InTaO{sub 7} with 4f-d{sup 10}-d{sup 0} configuration crystallized in a cubic system with the space group Fd3m was synthesized by a solid-state reaction method. NiOx-loaded Sm{sub 2}InTaO{sub 7} showed high photocatalytic activities for H{sub 2} evolution from pure water under visible light irradiation (lambda>400 nm). Changes in the photocatalytic activity with the calcination temperature of Sm{sub 2}InTaO{sub 7} and the amount of NiOx loaded indicated that the combination of highly crystallized Sm{sub 2}InTaO{sub 7} and a high dispersion of NiOx particles led to high photocatalytic activity. The high photocatalytic performance of NiOx-loaded Sm{sub 2}InTaO{sub 7} supported the existing view that the photocatalytic activity correlated with the lattice distortion. Density functional theory calculation indicated that strong dispersion from the hybridized In 5s 5p orbitals at the bottom of the conduction band was responsible for the high activity of photocatalyst Sm{sub 2}InTaO{sub 7}. - Graphical abstract: A new visible-light-response photocatalyst Sm{sub 2}InTaO{sub 7} with 4f-d{sup 10}-d{sup 0} configuration was developed. DFT calculation indicated that strong dispersion from the hybridized In 5s 5p orbitals was responsible for the high photocatalytic activity.

  10. Building America Case Study: Retrofitting a 1960s Split-Level, Cold-Climate Home, Westport, Connecticut; Whole-House Solutions for Existing Homes, Energy Efficiency & Renewable Energy (EERE)

    SciTech Connect (OSTI)

    2015-08-01

    ??National programs such as Home Performance with ENERGY STAR(R) and numerous other utility air sealing programs have brought awareness to homeowners of the benefits of energy efficiency retrofits. Yet, these programs tend to focus on the low-hanging fruit: air-sealing the thermal envelope and ductwork where accessible, switch to efficient lighting, and low-flow fixtures. At the other end of the spectrum, deep-energy retrofit programs are also being encouraged by various utilities across the country. While deep energy retrofits typically seek 50% energy savings, they are often quite costly and most applicable to gut-rehab projects. A significant potential for lowering energy usage in existing homes lies between the low hanging fruit and deep energy retrofit approaches - retrofits that save approximately 30% in energy over the existing conditions. A key is to be non-intrusive with the efficiency measures so the retrofit projects can be accomplished in occupied homes. This cold climate retrofit project involved the design and optimization of a home in Connecticut that sought to improve energy savings by at least 30% (excluding solar PV) over the existing home's performance. This report documents the successful implementation of a cost-effective solution package that achieved performance greater than 30% over the pre-retrofit - what worked, what did not, and what improvements could be made. Confirmation of successfully achieving 30% source energy savings over the pre-existing conditions was confirmed through energy modeling and comparison of the utility bills pre- and post- retrofit.

  11. Iron-rich perovskite in the Earth;s lower mantle

    SciTech Connect (OSTI)

    Mao, Z.; Lin, J.F.; Scott, H.P.; Watson, H.C.; Prakapenka, V.B.; Xiao, Y.; Chow, P.; McCammon, C. NIU

    2013-10-22

    The equations of state of perovskite with (Mg{sub 0.75},Fe{sub 0.25})SiO{sub 3} and MgSiO{sub 3} compositions have been investigated by synchrotron X-ray diffraction up to 130 GPa at 300 K in diamond anvil cells. Here we show that the addition of 25% Fe in MgSiO{sub 3} perovskite increases its density and bulk sound velocity (V{phi}) by 4-6% and 6-7%, respectively, at lower-mantle pressures. Based on concurrent synchrotron X-ray emission and Moessbauer spectroscopic studies of the samples, the increase in V{phi} and density can be explained by the occurrence of the low-spin Fe3+ and the extremely high-quadrupole component of Fe{sup 2+}. Combining these experimental results with thermodynamic modeling, our results indicate that iron-rich perovskite can produce an increase in density and a value of V{phi} that is compatible with seismic observations of reduced shear-wave velocity in regions interpreted as dense, stiff piles in the lower mantle. Therefore, the existence of the Fe-rich perovskite in the lower mantle may help elucidate the cause of the lower-mantle large low-shear-velocity provinces (LLSVPs) where enhanced density and V{phi} are seismically observed to anti-correlate with the reduced shear wave velocity.

  12. Seismic sources

    DOE Patents [OSTI]

    Green, Michael A. (Oakland, CA); Cook, Neville G. W. (Lafayette, CA); McEvilly, Thomas V. (Berkeley, CA); Majer, Ernest L. (El Cirrito, CA); Witherspoon, Paul A. (Berkeley, CA)

    1992-01-01

    Apparatus is described for placement in a borehole in the earth, which enables the generation of closely controlled seismic waves from the borehole. Pure torsional shear waves are generated by an apparatus which includes a stator element fixed to the borehole walls and a rotor element which is electrically driven to rapidly oscillate on the stator element to cause reaction forces transmitted through the borehole walls to the surrounding earth. Logitudinal shear waves are generated by an armature that is driven to rapidly oscillate along the axis of the borehole relative to a stator that is clamped to the borehole, to cause reaction forces transmitted to the surrounding earth. Pressure waves are generated by electrically driving pistons that press against opposite ends of a hydraulic reservoir that fills the borehole. High power is generated by energizing the elements at a power level that causes heating to over 150.degree. C. within one minute of operation, but energizing the elements for no more than about one minute.

  13. Study on small-strain behaviours of methane hydrate sandy sediments using discrete element method

    SciTech Connect (OSTI)

    Yu Yanxin; Cheng Yipik; Xu Xiaomin; Soga, Kenichi

    2013-06-18

    Methane hydrate bearing soil has attracted increasing interest as a potential energy resource where methane gas can be extracted from dissociating hydrate-bearing sediments. Seismic testing techniques have been applied extensively and in various ways, to detect the presence of hydrates, due to the fact that hydrates increase the stiffness of hydrate-bearing sediments. With the recognition of the limitations of laboratory and field tests, wave propagation modelling using Discrete Element Method (DEM) was conducted in this study in order to provide some particle-scale insights on the hydrate-bearing sandy sediment models with pore-filling and cementation hydrate distributions. The relationship between shear wave velocity and hydrate saturation was established by both DEM simulations and analytical solutions. Obvious differences were observed in the dependence of wave velocity on hydrate saturation for these two cases. From the shear wave velocity measurement and particle-scale analysis, it was found that the small-strain mechanical properties of hydrate-bearing sandy sediments are governed by both the hydrate distribution patterns and hydrate saturation.

  14. High speed point derivative microseismic detector

    DOE Patents [OSTI]

    Uhl, James Eugene; Warpinski, Norman Raymond; Whetten, Ernest Blayne

    1998-01-01

    A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves.

  15. High speed point derivative microseismic detector

    DOE Patents [OSTI]

    Uhl, J.E.; Warpinski, N.R.; Whetten, E.B.

    1998-06-30

    A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves. 9 figs.

  16. The insensitivity of reflected sh waves to anisotropy in an underlaying layered medium

    SciTech Connect (OSTI)

    Schoenberg, M.; Costa, J. )

    1991-11-01

    This paper reports on propagation in the plane of mirror symmetry of a monoclinic medium, with displacement normal to the plane which is the most general circumstance in anisotropic media for which pure shear-wave propagation can occur at all angles. Because the pure shear mode is uncoupled from the other two modes, its slowness surface in the plane is an ellipse. When the mirror symmetry plane is vertical the pure shear waves in this plane are SH waves and the elliptical SH sheet of the slowness surface is, in general, tilted with respect to the vertical axis. Consider a half-space of such a monoclinic medium, called medium M, overlain by a halfspace of isotropic medium I with plane SH waves incident on medium M propagating in the vertical symmetry plane of M. Contrary to the appearance of a lack of symmetry about the vertical axis due to the tilt of the SH-wave slowness ellipse, the reflection and transmission coefficients are symmetrical functions of the angle of incidence, and further, there exists an isotropic medium E with uniquely determined density and shear speed which gives exactly the same reflection and transmission coefficients underlying medium I as does monoclinic medium M. This means that the underlying monoclinic medium M can be replaced by isotropic medium E without changing the reflection and transmission coefficients for all values of the angle of incidence.

  17. Characterization of the alumina-zirconia ceramic system by ultrasonic velocity measurements

    SciTech Connect (OSTI)

    Carreon, Hector; Ruiz, Alberto; Medina, Ariosto; Barrera, Gerardo; Zarate, Juan

    2009-08-15

    In this work an alumina-zirconia ceramic composites have been prepared with {alpha}-Al{sub 2}O{sub 3} contents from 10 to 95 wt.%. The alumina-zirconia ceramic system was characterized by means of precise ultrasonic velocity measurements. In order to find out the factors affecting the variation in wave velocity, the ceramic composite have been examined by X-ray diffraction (XRD) and (SEM) scanning electron microscopy. It was found that the ultrasonic velocity measurements changed considerably with respect to the ceramic composite composition. In particular, we studied the behavior of the physical material property hardness, an important parameter of the ceramic composite mechanical properties, with respect to the variation in the longitudinal and shear wave velocities. Shear wave velocities exhibited a stronger interaction with microstructural and sub-structural features as compared to that of longitudinal waves. In particular, this phenomena was observed for the highest {alpha}-Al{sub 2}O{sub 3} content composite. Interestingly, an excellent correlation between ultrasonic velocity measurements and ceramic composite hardness was observed.

  18. Study of free vibrations of flexible shells with finite shear stiffness

    SciTech Connect (OSTI)

    Krys`ko, V.A.; Pavlov, S.P.; Sytnik, I.F.

    1995-10-01

    This article presents a numerical algorithm for solving dynamic nonlinear problems of the theory of plates and shells that can be described by equations of the Timoshenko type. These are hyperbolic equations and account for inertial rotation and the so-called {open_quotes}fast{close_quotes} shear waves created in plates. The latter are in fact the reason that frequencies differing by an order of magnitude are seen in the natural frequency spectrum of a plate. It is known that the Cauchy problem will be stiff if the ratio of the natural frequencies {much_gt}1. In accordance with the definition given by Hall and Watt, the problem is considered stiff if this ratio is on the order of 0(10) or higher. We deal with such a problem in this article. The presence of shear waves with high natural frequencies is the determining factor in choosing the method of numerical integration. In explicit methods, it follows satisfy the condition {Delta}t {much_lt} T{sub n}/{pi}, where T{sub n} is the smallest period of natural vibration of the system, i.e. an excessively small value is chosen for {Delta}t in the solution of stiff problems. Thus, Newmark`s method, with an implicit integration scheme, is used to numerically integrate a stiff system of equations-such as the system being considered here.

  19. Building America Technology Solutions for New and Existing Homes...

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

    Replacing Resistance Heating with Mini-Split Heat Pumps Building America Technology Solutions for New and Existing Homes: Replacing Resistance Heating with Mini-Split Heat Pumps In...

  20. Lowering Drilling Cost, Improving Operational Safety, and Reducing

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

    a splitting tensile strength method. This method is similar to ASTM C496-90 (standard test method for splitting tensile strength of cylindrical concrete specimens). For this...

  1. Using histograms to introduce randomization in the generation of ensembles of decision trees

    DOE Patents [OSTI]

    Kamath, Chandrika; Cantu-Paz, Erick; Littau, David

    2005-02-22

    A system for decision tree ensembles that includes a module to read the data, a module to create a histogram, a module to evaluate a potential split according to some criterion using the histogram, a module to select a split point randomly in an interval around the best split, a module to split the data, and a module to combine multiple decision trees in ensembles. The decision tree method includes the steps of reading the data; creating a histogram; evaluating a potential split according to some criterion using the histogram, selecting a split point randomly in an interval around the best split, splitting the data, and combining multiple decision trees in ensembles.

  2. ARM - Publications: Science Team Meeting Documents

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

    as well as microphysical and optical property assumptions. The Visible Infrared Solar-infrared Split-window Technique (VISST) and Solar infrared- Infrared-Split window...

  3. Interfacial Chemistry of III-V Semiconductors for Photoelectrochemical...

    Office of Scientific and Technical Information (OSTI)

    Photoelectrochemical Water Splitting Citation Details In-Document Search Title: Interfacial Chemistry of III-V Semiconductors for Photoelectrochemical Water Splitting You are ...

  4. Mapping Diffuse Seismicity Using Empirical Matched Field Processing Techniques

    SciTech Connect (OSTI)

    Wang, J; Templeton, D C; Harris, D B

    2011-01-21

    The objective of this project is to detect and locate more microearthquakes using the empirical matched field processing (MFP) method than can be detected using only conventional earthquake detection techniques. We propose that empirical MFP can complement existing catalogs and techniques. We test our method on continuous seismic data collected at the Salton Sea Geothermal Field during November 2009 and January 2010. In the Southern California Earthquake Data Center (SCEDC) earthquake catalog, 619 events were identified in our study area during this time frame and our MFP technique identified 1094 events. Therefore, we believe that the empirical MFP method combined with conventional methods significantly improves the network detection ability in an efficient matter.

  5. High-throughput screening and device for photocatalysts

    DOE Patents [OSTI]

    Lewis, Nathan S.; Katz, Jordan; Gingrich, Todd

    2015-09-08

    The disclosure relates to compositions, devices and methods for screening of photocatalysts for water-splitting.

  6. Building America Technology Solutions for New and Existing Homes: Replacing

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

    Resistance Heating with Mini-Split Heat Pumps | Department of Energy Replacing Resistance Heating with Mini-Split Heat Pumps Building America Technology Solutions for New and Existing Homes: Replacing Resistance Heating with Mini-Split Heat Pumps In this project, the Advanced Residential Integrated Solutions team investigated the suitability of mini-split heat pumps for multifamily retrofits. PDF icon Replacing Resistance Heating with Mini-Split Heat Pumps More Documents & Publications

  7. INL Seismic Monitoring Annual Report: January 1, 2008 – December 31, 2008

    SciTech Connect (OSTI)

    S. J. Payne; N. S. Carpenter; J. M. Hodges; R. G. Berg

    2009-09-01

    During 2008, the INL Seismic Monitoring Program evaluated 7,284 earthquakes from around the world, the western United States, and local region of the eastern Snake River Plain. 2,396 earthquakes and man-made blasts were evaluated within the local region outside and within a 161-km (or 100-mile) radius of INL. Of these events, 25 were small to moderate size earthquakes ranging in magnitude from 3.0 to 3.9. 823 earthquakes occurred within the 161-km radius of INL and over 300 events were associated with eight different earthquake swarms which were located in active regions of the Basin and Range Province that surrounds the eastern Snake River Plain. Eight microearthquakes in 2008 of magnitude (M) 2.0 and less were located within the eastern Snake River Plain, seven at or near the Craters of the Moon National Monument and one within the INL boundary. Further analyses of the anomalously deep focal depths (15 to 42 km) and different waveform characteristics of all Craters of the Moon National Monument events (1999-2008) suggest association with magmatic processes. From 1972 to 2008, INL located 36 other small-magnitude microearthquakes (M < 2.0) at depths (< 11 km) within the eastern Snake River Plain and attributes these events to regional tectonic tensional stresses.

  8. Predicting the spatial extent of injection-induced zones of enhanced permeability at the Northwest Geysers EGS Demonstration Project

    SciTech Connect (OSTI)

    Rutqvist, J.; Oldenburg, C.M.; Dobson, P.F.

    2010-02-01

    We present the results of coupled thermal, hydraulic, and mechanical (THM) modeling of a proposed stimulation injection associated with an Enhanced Geothermal System (EGS) demonstration project at the northwest part of The Geysers geothermal field, California. The project aims at creating an EGS by directly and systematically injecting cool water at relatively low pressure into a known High Temperature (about 280 to 350 C) Zone (HTZ) located under the conventional (240 C) steam reservoir at depths below 3 km. Accurate micro-earthquake monitoring from the start of the injection will be used as a tool for tracking the development of the EGS. We first analyzed historic injection and micro-earthquake data from an injection well (Aidlin 11), located about 3 miles to the west of the new EGS demonstration area. Thereafter, we used the same modeling approach to predict the likely extent of the zone of enhanced permeability for a proposed initial injection in two wells (Prati State 31 and Prati 32) at the new EGS demonstration area. Our modeling indicates that the proposed injection scheme will provide additional steam production in the area by creating a zone of permeability enhancement extending about 0.5 km from each injection well which will connect to the overlying conventional steam reservoir.

  9. Seismic Surface-Wave Tomography of Waste Sites - Final Report

    SciTech Connect (OSTI)

    Long, Timothy L.

    2000-09-14

    The objective of this study was to develop analysis programs for surface-wave group-velocity tomography, and apply these to three test areas. We succeeded by obtaining data covering two square areas that were 30 meters on a side, and a third area that was 16 meters on a side, in addition to a collaborative effort wherein we processed data from the Oak Ridge National Laboratory site. At all sites, usable group velocities were obtained for frequencies from 16 to 50 Hz using a sledgehammer source. The resulting tomographic images and velocity anomalies were sufficient to delineate suspected burial trenches (one 4-meters deep) and anomalous velocity structure related to rocks and disturbed soil. The success was not uniform because in portions of one area the inversion for shear-wave structure became unstable. More research is needed to establish a more robust inversion technique.

  10. Seismic safety margins research program. Phase I. Final report: plant/site selection and data collection (Project I)

    SciTech Connect (OSTI)

    Chuang, T. Y.

    1981-05-01

    Project I of Phase I of the Seismic Safety Margins Research Program (SSMRP) comprised two parts: the selection of a representative nuclear power plant/site for study in Phase I and the collection of data needed by the other SSMRP projects. Unit 1 of the Zion Nuclear Power Plant in Zion, Illinois, was selected for the SSMRP Phase I studies. The Zion plant and its site were found to be reasonably representative of operating and future plants with regard to its nuclear steam supply system; the type of containment structure (prestressed concrete); its electrical capacity (1100 MWe); its location (the Midwest); the peak seismic accelaration used for design (0.17g); and the properties of the underlying soil (the low-strain shear-wave velocity is 1650 ft/s in a 50- to 100-ft-thick layer of soil overlying sedimentary bedrock).

  11. The effects of confining pressure on the strength and elastic properties of the Paintbrush tuff recovered from boreholes USW NRG-6 and USW NRG-7/7A: Data report

    SciTech Connect (OSTI)

    Martin, R.J.; Noel, J.S.; Boyd, P.J.

    1997-09-01

    Experimental results are presented for bulk and mechanical properties measurements on specimens of the Paintbrush tuff recovered from the USW NRG-6 and USW NRG-7/7A borehole at Yucca Mountain, Nevada. Measurements have been performed on five thermal/mechanical units: TCw, PTn, TSw2, and TSw3. The following bulk properties are reported for each specimen: dry bulk density, saturated bulk density, average grain density and porosity. Confined compression to failure tests were performed on selected specimens recovered from the boreholes at confining pressures of 5 and 10 MPa. In addition, compressional and shear wave velocities were measured on the specimens prior to testing. Measurements were conducted under drained conditions at room temperature on nominally water saturated specimens. The nominal strain rate for the experiments was 10{sup -5} s{sup -1}.

  12. Seismically-induced soil amplification at the DOE Paducah Gaseous Diffusion Plant site

    SciTech Connect (OSTI)

    Sykora, D.W.; Haynes, M.E. . Geotechnical Lab.); Brock, W.R.; Hunt, R.J.; Shaffer, K.E. )

    1991-01-01

    A site-specific earthquake site response (soil amplification) study is being conducted for the Department of Energy (DOE), Paducah Gaseous Diffusion Plant (PGDP). This study is pursuant to an upgraded Final Safety Analysis Report in accordance with requirements specified by DOE. The seismic hazard at PGDP is dominated by the New Madrid Seismic Zone. Site-specific synthetic earthquake records developed by others were applied independently to four soil columns with heights above baserock of about 325 ft. The results for the 1000-year earthquake event indicate that the site period is between 1.0 and 1.5 sec. Incident shear waves are amplified at periods of motion greater than 0.15 sec. The peak free-field horizontal acceleration, occurring at very low periods, is 0.28 g. 13 refs., 13 figs.

  13. Evaluation of liquefaction potential for building code

    SciTech Connect (OSTI)

    Nunziata, C.; De Nisco, G.; Panza, G. F.

    2008-07-08

    The standard approach for the evaluation of the liquefaction susceptibility is based on the estimation of a safety factor between the cyclic shear resistance to liquefaction and the earthquake induced shear stress. Recently, an updated procedure based on shear-wave velocities (V{sub s}) has been proposed which could be more easily applied.These methods have been applied at La Plaja beach of Catania, that experienced liquefaction because of the 1693 earthquake. The detailed geotechnical and V{sub s} information and the realistic ground motion computed for the 1693 event let us compare the two approaches. The successful application of the V{sub s} procedure, slightly modified to fit historical and safety factor information, even if additional field performances are needed, encourages the development of a guide for liquefaction potential analysis, based on well defined V{sub s} profiles to be included in the italian seismic code.

  14. 3D Seismic Experimentation and Advanced Processing/Inversion Development for Investigations of the Shallow Subsurface

    SciTech Connect (OSTI)

    Levander, Alan Richard; Zelt, Colin A.

    2015-03-17

    The work plan for this project was to develop and apply advanced seismic reflection and wide-angle processing and inversion techniques to high resolution seismic data for the shallow subsurface to seismically characterize the shallow subsurface at hazardous waste sites as an aid to containment and cleanup activities. We proposed to continue work on seismic data that we had already acquired under a previous DoE grant, as well as to acquire additional new datasets for analysis. The project successfully developed and/or implemented the use of 3D reflection seismology algorithms, waveform tomography and finite-frequency tomography using compressional and shear waves for high resolution characterization of the shallow subsurface at two waste sites. These two sites have markedly different near-surface structures, groundwater flow patterns, and hazardous waste problems. This is documented in the list of refereed documents, conference proceedings, and Rice graduate theses, listed below.

  15. Bulk and mechanical properties of the Paintbrush tuff recovered from boreholes UE25 NRG-4 and -5: Data report

    SciTech Connect (OSTI)

    Boyd, P.J.; Noel, J.S.; Martin, R.J. [New England Research, Inc., White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)

    1996-09-01

    Experimental results are presented for bulk and mechanical properties measurements on specimens of the Paintbrush tuff recovered from boreholes UE25 NRG-4 and -5, at Yucca Mountain, Nevada. Measurements have been performed on three thermal/mechanical units, PTn, TSwl, and TSw2. On each specimen the following bulk properties have been reported: dry bulk density, saturated bulk density, average grain density, and porosity. Unconfined compression to failure, confined compression to failure, and indirect tensile strength tests were performed on selected specimens recovered from the boreholes. In addition, compressional and shear wave velocities were measured on specimens designated for unconfined compression and confined compression experiments. Measurements were conducted at room temperature on nominally water-saturated specimens. The nominal rate for the fracture experiments was 10{sup -5}s{sup -1}.

  16. Pressure effect on elastic anisotropy of crystals from ab initio simulations: The case of silicate garnets

    SciTech Connect (OSTI)

    Mahmoud, A.; Erba, A. Dovesi, R.; Doll, K.

    2014-06-21

    A general methodology has been devised and implemented into the solid-state ab initio quantum-mechanical CRYSTAL program for studying the evolution under geophysical pressure of the elastic anisotropy of crystalline materials. This scheme, which fully exploits both translational and point symmetry of the crystal, is developed within the formal frame of one-electron Hamiltonians and atom-centered basis functions. Six silicate garnet end-members, among the most important rock-forming minerals of the Earth's mantle, are considered, whose elastic anisotropy is fully characterized under high hydrostatic compressions, up to 60 GPa. The pressure dependence of azimuthal anisotropy and shear-wave birefringence of seismic wave velocities for these minerals are accurately simulated and compared with available single-crystal measurements.

  17. A wall-crawling robot for reactor vessel inspection in advanced reactors

    SciTech Connect (OSTI)

    Spelt, P.F.; Crane, C.; Feng, L.; Abidi, M.; Tosunoglu, S.

    1994-06-01

    A consortium of four universities and the Center for Engineering Systems Advanced Research of the Oak Ridge National Laboratory has designed a prototype wall-crawling robot to perform weld inspection in advanced nuclear reactors. Design efforts for the reactor vessel inspection robot (RVIR) concentrated on the Advanced Liquid Metal Reactor because it presents the most demanding environment in which such a robot must operate. The RVIR consists of a chassis containing two sets of suction cups that can alternately grasp the side of the vessel being inspected, providing both locomotion and steering functions. Sensors include three CCD cameras and a weld inspection device based on new shear-wave technology. The restrictions of the inspection environment presented major challenges to the team. These challenges were met in the prototype, which has been tested in a non-radiation, room-temperature mockup of the robot work environment and shown to perform as expected.

  18. Surface-wave and refraction tomography at the FACT Site, Sandia National Laboratories, Albuquerque, New Mexico.

    SciTech Connect (OSTI)

    Abbott, Robert E.; Bartel, Lewis Clark; Pullammanappallil, Satish; Engler, Bruce Phillip

    2006-08-01

    We present a technique that allows for the simultaneous acquisition and interpretation of both shear-wave and compressive-wave 3-D velocities. The technique requires no special seismic sources or array geometries, and is suited to studies with small source-receiver offsets. The method also effectively deals with unwanted seismic arrivals by using the statistical properties of the data itself to discriminate against spurious picks. We demonstrate the technique with a field experiment at the Facility for Analysis, Calibration, and Testing at Sandia National Laboratories, Albuquerque, New Mexico. The resulting 3-D shear-velocity and compressive-velocity distributions are consistent with surface geologic mapping. The averaged velocities and V{sub p}/V{sub s} ratio in the upper 30 meters are also consistent with examples found in the scientific literature.

  19. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO{sub 2} Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    SciTech Connect (OSTI)

    Michael F. Morea

    1997-03-14

    The Buena Vista Hills field is located about 25 miles southwest of Bakersfield, in Kern County, California, about two miles north of the city of Taft, and five miles south of the Elk Hills field. The Antelope Shale zone was discovered at the Buena Vista Hills field in 1952, and has since been under primary production. Little research was done to improve the completion techniques during the development phase in the 1950s, so most of the wells are completed with about 1000 ft of slotted liner. The proposed pilot consists of four existing producers on 20 acre spacing with a new 10 acre infill well drilled as the pilot CO{sub 2} injector. Most of the reservoir characterization of the first phase of the project will be performed using data collected in the pilot pattern wells. This is the first annual report of the project. It covers the period February 12, 1996 to February 11, 1997. During this period the Chevron Murvale 653Z-26B well was drilled in Section 26-T31S/R23E in the Buena Vista Hills field, Kern County, California. The Monterey Formation equivalent Brown and Antelope Shales were continuously cored, the zone was logged with several different kinds of wireline logs, and the well was cased to a total depth of 4907 ft. Core recovery was 99.5%. Core analyses that have been performed include Dean Stark porosity, permeability and fluid saturations, field wettability, anelastic strain recovery, spectral core gamma, profile permeametry, and photographic imaging. Wireline log analysis includes mineral-based error minimization (ELAN), NMR T2 processing, and dipole shear wave anisotropy. A shear wave vertical seismic profile was acquired after casing was set and processing is nearly complete.

  20. Advanced reservoir characterization in the Antelope Shale to establish the viability of CO2 enhanced oil recovery in California`s Monterey Formation siliceous shales. Annual report, February 7, 1997--February 6, 1998

    SciTech Connect (OSTI)

    Morea, M.F.

    1998-06-01

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO{sub 2} enhanced oil recovery project in the antelope Shale in Buena Vista Hills Field. The proposed pilot consists of four existing producers on 20 acre spacing with a new 10 acre infill well drilled as the pilot CO{sub 2} injector. Most of the reservoir characterization during Phase 1 of the project will be performed using data collected in the pilot pattern wells. During this period the following tasks have been completed: laboratory wettability; specific permeability; mercury porosimetry; acoustic anisotropy; rock mechanics analysis; core description; fracture analysis; digital image analysis; mineralogical analysis; hydraulic flow unit analysis; petrographic and confocal thin section analysis; oil geochemical fingerprinting; production logging; carbon/oxygen logging; complex lithologic log analysis; NMR T2 processing; dipole shear wave anisotropy logging; shear wave vertical seismic profile processing; structural mapping; and regional tectonic synthesis. Noteworthy technological successes for this reporting period include: (1) first (ever) high resolution, crosswell reflection images of SJV sediments; (2) first successful application of the TomoSeis acquisition system in siliceous shales; (3) first detailed reservoir characterization of SJV siliceous shales; (4) first mineral based saturation algorithm for SJV siliceous shales, and (5) first CO{sub 2} coreflood experiments for siliceous shale. Preliminary results from the CO{sub 2} coreflood experiments (2,500 psi) suggest that significant oil is being produced from the siliceous shale.

  1. Advanced reservoir characterization in the Antelope Shale to establish the viability of CO{sub 2} enhanced oil recovery in California`s Monterey Formation siliceous shales. Annual report, February 12, 1996--February 11, 1997

    SciTech Connect (OSTI)

    Toronyi, R.M.

    1997-12-01

    The Buena Vista Hills field is located about 25 miles southwest of Bakersfield, in Kern County, California, about two miles north of the city of Taft, and five miles south of the Elk Hills field. The Antelope Shale zone was discovered at the Buena Vista Hills field in 1952, and has since been under primary production. Little research was done to improve the completion techniques during the development phase in the 1950s, so most of the wells are completed with about 1000 ft of slotted liner. The proposed pilot consists of four existing producers on 20 acre spacing with a new 10 acre infill well drilled as the pilot CO{sub 2} injector. Most of the reservoir characterization of the first phase of the project will be performed using data collected in the pilot pattern wells. This is the first annual report of the project. It covers the period February 12, 1996 to February 11, 1997. During this period the Chevron Murvale 653Z-26B well was drilled in Section 26-T31S/R23E in the Buena Vista Hills field, Kern County, California. The Monterey Formation equivalent Brown and Antelope Shales were continuously cored, the zone was logged with several different kinds of wireline logs, and the well was cased to a total depth of 4907 ft. Core recovery was 99.5%. Core analyses that have been performed include Dean Stark porosity, permeability and fluid saturations, field wettability, anelastic strain recovery, spectral core gamma, profile permeametry, and photographic imaging. Wireline log analysis includes mineral-based error minimization (ELAN), NMR T2 processing, and dipole shear wave anisotropy. A shear wave vertical seismic profile was acquired after casing was set and processing is nearly complete.

  2. Experimental and first-principles studies on the elastic properties of α-hafnium metal under pressure

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

    Qi, Xintong; Wang, Xuebing; Chen, Ting; Li, Baosheng

    2016-03-30

    Compressional and shear wave velocities of the α phase of hafnium have been measured up to 10.4 GPa at room temperature using ultrasonic interferometry in a multi-anvil apparatus. A finite strain equation of state analysis yielded Ks0 = 110.4 (5) GPa, G0 = 54.7(5) GPa,Ks0' = 3.7 and G0' = 0.6 for the elastic bulk and shear moduli and their pressure derivatives at ambient conditions. Complementary to the experimental data, the single crystal elastic constants, elastic anisotropy and the unit cell axial ratio c/a of α-hafnium at high pressures were investigated by Density Functional Theory (DFT) based first principles calculations.more » A c/a value of 1.605 is predicted for α-Hf at 40 GPa, which is in excellent agreement with previous experimental results. The low-pressure derivative of the shear modulus observed in our experimental data up to 10 GPa was found to originate from the elastic constant C44 which exhibits negligible pressure dependence within the current experimental pressure range. At higher pressures (>10 GPa), C44 was predicted to soften and the shear wave velocity νS trended to decrease with pressure, which can be interpreted as a precursor to the α-ω transition similar to that observed in other group IV elements (titanium and zirconium). Here, the acoustic velocities, bulk and shear moduli, and the acoustic Debye temperature (θD = 240.1 K) determined from the current experiments were all compared well with those predicted by our theoretical DFT calculations.« less

  3. Duke University Research Associate Awarded 2014 Prize to Support Research

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

    Ductless Mini-Split Air Conditioners Ductless Mini-Split Air Conditioners A ductless mini-split air conditioner is one solution to cooling part of a house. | Photo courtesy of ©iStockphoto/LUke1138. A ductless mini-split air conditioner is one solution to cooling part of a house. | Photo courtesy of ©iStockphoto/LUke1138. Ductless, mini split-system air-conditioners (mini splits) have numerous potential applications in residential, commercial, and institutional buildings. The most common

  4. ARM - Publications: Science Team Meeting Documents

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

    ERBE OLR and Cloud Type by Split Window Inoue, T.(a) and Ackerman, S.A.(b), Meteorological ... Using collocated ERBE and split windowAVHRR on board NOAA-9, we studied the relationship ...

  5. Direct Detector for Terahertz Radiation - Energy Innovation Portal

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

    the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating...

  6. Georgia Power - Commercial Energy Efficiency Program | Department...

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

    or halogen: 6.50 LED lamp replacing incandescent or halogen: 9 Lighting Occupancy Sensor: 7 Lighting Daylight Sensor: 25 SplitPackaged Air Conditioners: 20-30ton Split...

  7. PHEVs Component Requirements and Efficiencies

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

    Fuel Consumption l100km Electrical Consumption Whkm Conventional Split HEV PHEV 8kWh Split Optimum Engine Power PHEV 12 kWh Series Thermostat Control PHEV 16 kWh Series ...

  8. Overview of DOE Production Work

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

    ... FCTO. * The DOE Photoelectrochemical Hydrogen Production Working Group published the Springer Brief in Energy: "Photoelectrochemical Water Splitting: Standards, Experimental ...

  9. DOE Technical Targets for Hydrogen Production from Photoelectrochemical

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

    Water Splitting | Department of Energy from Photoelectrochemical Water Splitting DOE Technical Targets for Hydrogen Production from Photoelectrochemical Water Splitting These tables list the U.S. Department of Energy (DOE) technical targets and example cost and performance parameter values that achieve the targets for hydrogen production from photoelectrochemical water splitting. The tables are organized into separate sections for photoelectrode systems and dual bed photocatalyst systems.

  10. DOE Technical Targets for Hydrogen Production from Thermochemical Water

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

    Splitting | Department of Energy from Thermochemical Water Splitting DOE Technical Targets for Hydrogen Production from Thermochemical Water Splitting These tables list the U.S. Department of Energy (DOE) technical targets and example cost and performance parameter values that achieve the targets for hydrogen production from thermochemical water splitting. More information about targets can be found in the Hydrogen Production section of the Fuel Cell Technologies Office's Multi-Year

  11. NREL Photoelectrode Research Advances Hydrogen Production Efforts

    SciTech Connect (OSTI)

    Gu, Jing

    2015-12-01

    Scientists have created a high-performing photoelectrode that boosts the ability of solar water-splitting to produce hydrogen.

  12. Jesse Bergkamp | Center for Bio-Inspired Solar Fuel Production

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

    Jesse Bergkamp Graduate student Subtask 4 project: "Synthesis of porphyrin and phthalocyanine dyes for photoelectrochemical water splitting

  13. DOE's Launch of High-Efficiency Thermiekectrics Projects | Department of

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

    4 Diesel Engine Emissions Reduction (DEER) Conference Presentation: National Renewable Energy Laboratory PDF icon 2004_deer_lawson.pdf More Documents & Publications DOE's Gasoline/Diesel PM Split Study DOE's Gasoline/Diesel PM Split Study Collaborative Lubricating Oil Study on Emissions (CLOSE) Project

    3 DEER Conference Presentation: Desert Research Institute PDF icon 2003_deer_fujita.pdf More Documents & Publications DOE's Gasoline/Diesel PM Split Study DOE's Gasoline/Diesel PM Split

  14. INL Seismic Monitoring Annual Report: January 1, 2007 - December 31, 2007

    SciTech Connect (OSTI)

    S. J. Payne; N. S. Carpenter; J. M. Hodges; R. G. Berg

    2008-09-01

    During 2007, the INL Seismic Monitoring Program evaluated 2,515 earthquakes from around the world, the western United States, and local region of the eastern Snake River Plain. 671 earthquakes and man-made blasts occurred within the local region outside and within a 161-km (or 100-mile) radius of INL. Of these events, eleven were small to moderate size earthquakes ranging in magnitude from 3.0 to 4.8. 341 earthquakes occurred within the 161-km radius of INL and the majority of these earthquakes were located in active regions of the Basin and Range Province that surrounds the ESRP. Three earthquakes were located within the ESRP at Craters of the Moon National Monument. The earthquakes were of Mc 0.9, 1.4, and 1.8. Since 1972, INL has recorded 36 small-magnitude microearthquakes (M < 2.0) within the ESRP.

  15. The Impact of Injection on Seismicity at The Geyses, CaliforniaGeothermal Field

    SciTech Connect (OSTI)

    Majer, Ernest L.; Peterson, John E.

    2006-09-25

    Water injection into geothermal systems has often become arequired strategy to extended and sustain production of geothermalresources. To reduce a trend of declining pressures and increasingnon-condensable gas concentrations in steam produced from The Geysers,operators have been injecting steam condensate, local rain and streamwaters, and most recently treated wastewater piped to the field fromneighboring communities. If geothermal energy is to provide a significantincrease in energy in the United States (US Department of Energy (DOE)goal is 40,000 megawatts by 2040), injection must play a larger role inthe overall strategy, i.e., enhanced geothermal systems, (EGS). Presentedin this paper are the results of monitoring microseismicity during anincrease in injection at The Geysers field in California using data froma high-density digital microearthquake array. Although seismicity hasincreased due to increased injection it has been found to be somewhatpredicable, thus implying that intelligent injection control may be ableto control large increases in seismicity.

  16. ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS

    SciTech Connect (OSTI)

    Thurman E. Scott, Jr., Ph.D.; Younane Abousleiman, Ph.D.; Musharraf Zaman, Ph.D., P.E.

    2002-04-30

    Three major goals were accomplished during this phase. First, a study was completed of the effects of stress-induced changes in anisotropic elastic moduli in sandstone. Second, a new method for measuring the anisotropic poroelastic moduli from acoustic data was developed. Third, a series of triaxial experiments were conducted on unconsolidated sands to identify pressure/stress conditions where liquefaction occurs under high confining pressures. Stress-induced changes in anisotropic Young's moduli and shear moduli were observed during deformational pathway experiments. A new method was made for the acquisition of compressional and shear wave velocities along a series of 3-dimensional raypaths through a core sample as it is subjected to deformation. Three different deformational pathway experiments were conducted. During the hydrostatic deformation experiment, little or no anisotropy was observed in either the Young's moduli or shear moduli. Significant deformational anisotropies were observed in both moduli during the uniaxial strain test and the triaxial compression experiment but each had a different nature. During the triaxial experiment the axial and lateral Young's moduli and shear moduli continued to diverge as load was applied. During the uniaxial strain experiment the anisotropy was ''locked in'' early in the loading phase but then remained steady as both the confining pressure and axial stress were applied. A new method for measuring anisotropic Biot's effective stress parameters has also been developed. The method involves measuring the compressional and shear wave velocities in the aforementioned acoustic velocity experiments while varying stress paths. For a stress-induced transversely isotropic medium the acoustic velocity data are utilized to calculate the five independent elastic stiffness components. Once the elastic stiffness components are determined these can be used to calculate the anisotropic Biot's effective stress parameters, {alpha}{sub v} and {alpha}{sub h}, using the equations of Abousleiman et al. (1996). A series of experiments have been conducted, on an initially inherently isotropic Berea sandstone rock sample, to dynamically determine these anisotropic Biot's parameters during deformational pathway experiments. Data acquired during hydrostatic, triaxial, and uniaxial strain pathway experiments indicates that Biot's effective stress parameter changes significantly if the applied stresses are not hydrostatic. Variations, as large as 20% between the axial (vertical) and lateral (horizontal) Biot's effective stress parameters, were observed in some experiments. A series of triaxial compression experiments have been conducted on unconsolidated sand (Oil Creek sand) to determine the pressure/stress conditions which would be favorable for liquefaction. Liquefaction of geopressured sands is thought to be one of the major causative mechanisms of damaging shallow water flows. The experiments were developed to determine if: (1) liquefaction could be made to occur in this particular sand at high confining pressures, and (2) the state of liquefication had the same nature at high pressure conditions typical of shallow water flows as it does in low confining pressure soil mechanics tests. A series of undrained triaxial experiments were successfully used to document that the Oil Creek sand could undergo liquefaction. The nature (i.e., the shape of the deformational pathway in mean pressure/shear stress space) was very similar to those observed in soil mechanics experiments. The undrained triaxial experiments also indicated that this sand would strain soften at relatively high confining pressures--a necessary precursor to liquefaction. These experiments serve as a starting point for a series of acoustic experiments to determine the signature of compressional and shear wave properties as the sand packs approach the state of liquefaction (and shallow water flows).

  17. Technical Basis for Certification of Seismic Design Criteria for the Waste Treatment Plant, Hanford, Washington

    SciTech Connect (OSTI)

    Brouns, T.M.; Rohay, A.C. [Pacific Northwest National Laboratory, Richland, WA (United States); Youngs, R.R. [Geomatrix Consultants, Inc., Oakland, CA (United States); Costantino, C.J. [C.J. Costantino and Associates, Valley, NY (United States); Miller, L.F. [U.S. Department of Energy, Office of River Protection, Richland, WA (United States)

    2008-07-01

    In August 2007, Secretary of Energy Samuel W. Bodman approved the final seismic and ground motion criteria for the Waste Treatment and Immobilization Plant (WTP) at the Department of Energy's (DOE) Hanford Site. Construction of the WTP began in 2002 based on seismic design criteria established in 1999 and a probabilistic seismic hazard analysis completed in 1996. The design criteria were reevaluated in 2005 to address questions from the Defense Nuclear Facilities Safety Board (DNFSB), resulting in an increase by up to 40% in the seismic design basis. DOE announced in 2006 the suspension of construction on the pretreatment and high-level waste vitrification facilities within the WTP to validate the design with more stringent seismic criteria. In 2007, the U.S. Congress mandated that the Secretary of Energy certify the final seismic and ground motion criteria prior to expenditure of funds on construction of these two facilities. With the Secretary's approval of the final seismic criteria in the summer of 2007, DOE authorized restart of construction of the pretreatment and high-level waste vitrification facilities. The technical basis for the certification of seismic design criteria resulted from a two-year Seismic Boreholes Project that planned, collected, and analyzed geological data from four new boreholes drilled to depths of approximately 1400 feet below ground surface on the WTP site. A key uncertainty identified in the 2005 analyses was the velocity contrasts between the basalt flows and sedimentary interbeds below the WTP. The absence of directly-measured seismic shear wave velocities in the sedimentary interbeds resulted in the use of a wider and more conservative range of velocities in the 2005 analyses. The Seismic Boreholes Project was designed to directly measure the velocities and velocity contrasts in the basalts and sediments below the WTP, reanalyze the ground motion response, and assess the level of conservatism in the 2005 seismic design criteria. The characterization and analysis effort included 1) downhole measurements of the velocity properties (including uncertainties) of the basalt/interbed sequences, 2) confirmation of the geometry of the contact between the various basalt and interbedded sediments through examination of retrieved core from the core-hole and data collected through geophysical logging of each borehole, and 3) prediction of ground motion response to an earthquake using newly acquired and historic data. The data and analyses reflect a significant reduction in the uncertainty in shear wave velocities below the WTP and result in a significantly lower spectral acceleration (i.e., ground motion). The updated ground motion response analyses and corresponding design response spectra reflect a 25% lower peak horizontal acceleration than reflected in the 2005 design criteria. These results provide confidence that the WTP seismic design criteria are conservative. (authors)

  18. Structure of the Crust beneath Cameroon, West Africa, from the Joint Inversion of Rayleigh Wave Group Velocities and Receiver Functions

    SciTech Connect (OSTI)

    Tokam, A K; Tabod, C T; Nyblade, A A; Julia, J; Wiens, D A; Pasyanos, M E

    2010-02-18

    The Cameroon Volcanic Line (CVL) is a major geologic feature that cuts across Cameroon from the south west to the north east. It is a unique volcanic lineament which has both an oceanic and a continental sector and consists of a chain of Tertiary to Recent, generally alkaline volcanoes stretching from the Atlantic island of Pagalu to the interior of the African continent. The oceanic sector includes the islands of Bioko (formerly Fernando Po) and Sao Tome and Principe while the continental sector includes the Etinde, Cameroon, Manengouba, Bamboutos, Oku and Mandara mountains, as well as the Adamawa and Biu Plateaus. In addition to the CVL, three other major tectonic features characterize the region: the Benue Trough located northwest of the CVL, the Central African Shear Zone (CASZ), trending N70 degrees E, roughly parallel to the CVL, and the Congo Craton in southern Cameroon. The origin of the CVL is still the subject of considerable debate, with both plume and non-plume models invoked by many authors (e.g., Deruelle et al., 2007; Ngako et al, 2006; Ritsema and Allen, 2003; Burke, 2001; Ebinger and Sleep, 1998; Lee et al, 1994; Dorbath et al., 1986; Fairhead and Binks, 1991; King and Ritsema, 2000; Reusch et al., 2010). Crustal structure beneath Cameroon has been investigated previously using active (Stuart et al, 1985) and passive (Dorbath et al., 1986; Tabod, 1991; Tabod et al, 1992; Plomerova et al, 1993) source seismic data, revealing a crust about 33 km thick at the south-western end of the continental portion of the CVL (Tabod, 1991) and the Adamawa Plateau, and thinner crust (23 km thick) beneath the Garoua Rift in the north (Stuart et al, 1985) (Figure 1). Estimates of crustal thickness obtained using gravity data show similar variations between the Garoua rift, Adamawa Plateau, and southern part of the CVL (Poudjom et al., 1995; Nnange et al., 2000). In this study, we investigate further crustal structure beneath the CVL and the adjacent regions in Cameroon using 1-D shear wave velocity models obtained from the joint inversion of Rayleigh wave group velocities and P-receiver functions for 32 broadband seismic stations. From the 1-D shear wave velocity models, we obtain new insights into the composition and structure of the crust and upper mantle across Cameroon. After briefly reviewing the geological framework of Cameroon, we describe the data and the joint inversion method, and then interpret variations in crustal structure found beneath Cameroon in terms of the tectonic history of the region.

  19. In the OSTI Collections: Fission Theory | OSTI, US Dept of Energy, Office

    Office of Scientific and Technical Information (OSTI)

    of Scientific and Technical Information Fission Theory How do atoms split Interest in the details Macroscopic-microscopic approaches Microscopic approaches Improved theory and design References Additional References Research Organizations Reports available from OSTI's Information Bridge How do atoms split? The main influences on the splitting of atoms were understood in at least a rough way almost as soon as nuclear fission was discovered in 1938. An atom's nucleus is composed of two kinds

  20. Interfacial Chemistry of III-V Semiconductors for Photoelectrochemical

    Office of Scientific and Technical Information (OSTI)

    Water Splitting (Journal Article) | SciTech Connect Interfacial Chemistry of III-V Semiconductors for Photoelectrochemical Water Splitting Citation Details In-Document Search Title: Interfacial Chemistry of III-V Semiconductors for Photoelectrochemical Water Splitting Authors: Wood, B C ; Schwegler, E ; Choi, W I ; Ogitsu, T Publication Date: 2013-04-15 OSTI Identifier: 1129977 Report Number(s): LLNL-JRNL-635637 DOE Contract Number: W-7405-ENG-48 Resource Type: Journal Article Resource

  1. Alternative Refrigerant Evaluation for High-Ambient-Temperature

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

    Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners | Department of Energy Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners The Oak Ridge National Laboratory High-Ambient-Temperature Evaluation Program for Low Global Warming Potential (Low-GWP)

  2. 15.01.21 RH Computational and Experimental ID - JCAP

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

    Computational and Experimental Identification of an Earth-Abundant Light Absorber for Solar Water Splitting Yan, Q. et al. Mn2V2O7: An Earth Abundant Light Absorber for Solar Water Splitting. Advanced Energy Materials, DOI: 10.1002/aenm.201401840 (2015). Scientific Achievement Computation, synthesis, and spectroscopy are used to first identify and then study the earth-abundant Mn2V2O7 as a highly promising light absorber for photocatalytic water splitting. Significance & impact The detailed

  3. Strontium Transportation Type B Report-Fina

    Office of Environmental Management (EM)

    Department of Energy Strategies to Address Split Incentives in Multifamily Buildings Strategies to Address Split Incentives in Multifamily Buildings Better Buildings Neighborhood Program Multifamily / Low-Income Peer Exchange Call: Strategies to Address Split Incentives in Multifamily Buildings, Call Slides and Discussion Summary, April 26, 2012. PDF icon Call Slides and Discussion Summary More Documents & Publications Outreach to Multifamily Landlords and Tenants Stewards of Affordable

  4. Elastic-Waveform Inversion with Compressive Sensing for Sparse Seismic Data

    SciTech Connect (OSTI)

    Lin, Youzuo; Huang, Lianjie

    2015-01-26

    Accurate velocity models of compressional- and shear-waves are essential for geothermal reservoir characterization and microseismic imaging. Elastic-waveform inversion of multi-component seismic data can provide high-resolution inversion results of subsurface geophysical properties. However, the method requires seismic data acquired using dense source and receiver arrays. In practice, seismic sources and/or geophones are often sparsely distributed on the surface and/or in a borehole, such as 3D vertical seismic profiling (VSP) surveys. We develop a novel elastic-waveform inversion method with compressive sensing for inversion of sparse seismic data. We employ an alternating-minimization algorithm to solve the optimization problem of our new waveform inversion method. We validate our new method using synthetic VSP data for a geophysical model built using geologic features found at the Raft River enhanced-geothermal-system (EGS) field. We apply our method to synthetic VSP data with a sparse source array and compare the results with those obtained with a dense source array. Our numerical results demonstrate that the velocity mode ls produced with our new method using a sparse source array are almost as accurate as those obtained using a dense source array.

  5. An analytical and numerical study of the nonlinear reflection at a stress-free surface

    SciTech Connect (OSTI)

    Romer, Anne Kim, Jin-Yeon; Jacobs, Laurence J.

    2015-03-31

    Implementation of the ultrasonic second harmonic generation has typically been restricted to simple setups such as through-transmission or Rayleigh surface waves. Recent research has evaluated the second harmonic waves generation in P- and SV- waves reflected from a stress-free surface to enable the single-sided interrogation of a specimen. This research considers the second harmonic generation in an aluminum specimen, which is analytically evaluated using an approach based on a perturbation method. Here, the model is chosen to mimic an experimental setup where the longitudinal wave is generated at oblique angle using a wedge transducer. Due to the mode conversion at the interface of the wedge and the specimen, it is necessary to evaluate longitudinal and shear waves, determining all second harmonic waves generated in the bulk and at the stress-free boundary. The theoretically developed model is then implemented in a commercial finite element code, COMSOL, using increasing fundamental wave amplitudes for different values of third order elastic constants. The results of this computational model verify the analytical approach and the proposed measurement setup, taking into account assumptions and approximations of the solution procedure. Furthermore, the computational model is used to draw important conclusions relevant to the experimental setup, including the need to avoid interaction with diffracted waves.

  6. 4-D High-Resolution Seismic Reflection Monitoring of Miscible CO2 Injected into a Carbonate Reservoir

    SciTech Connect (OSTI)

    Richard D. Miller; Abdelmoneam E. Raef; Alan P. Byrnes; William E. Harrison

    2007-06-30

    The objective of this research project was to acquire, process, and interpret multiple high-resolution 3-D compressional wave and 2-D, 2-C shear wave seismic data in the hopes of observing changes in fluid characteristics in an oil field before, during, and after the miscible carbon dioxide (CO{sub 2}) flood that began around December 1, 2003, as part of the DOE-sponsored Class Revisit Project (DOE No.DE-AC26-00BC15124). Unique and key to this imaging activity is the high-resolution nature of the seismic data, minimal deployment design, and the temporal sampling throughout the flood. The 900-m-deep test reservoir is located in central Kansas oomoldic limestones of the Lansing-Kansas City Group, deposited on a shallow marine shelf in Pennsylvanian time. After 30 months of seismic monitoring, one baseline and eight monitor surveys clearly detected changes that appear consistent with movement of CO{sub 2} as modeled with fluid simulators and observed in production data. Attribute analysis was a very useful tool in enhancing changes in seismic character present, but difficult to interpret on time amplitude slices. Lessons learned from and tools/techniques developed during this project will allow high-resolution seismic imaging to be routinely applied to many CO{sub 2} injection programs in a large percentage of shallow carbonate oil fields in the midcontinent.

  7. Borehole SASW testing to evaluate log(G{sub max}) - log({sigma}{prime}) relationships in situ

    SciTech Connect (OSTI)

    Kalinski, M.E.; Stokoe, K.H. II; Young, Y.L.; Roesset, J.M.

    1999-07-01

    A new method is being developed for the in-situ measurement of shear wave velocity, V{sub s}, in the soil surrounding a borehole. The method involves the measurement of axially propagating surface waves inside an uncased borehole using the Spectral-Analysis-of-Surface-Waves (SASW) approach. Testing if performed with instrumentation housed inside an inflatable tool. Inflation pressures applied by the tool are used to vary radial stresses in the soil surrounding the borehole. Surface wave velocities over a range of frequencies are measured at each inflation pressure. These measurements are then theoretically modeled so that the variation in V{sub s} (an hence small-strain shear module, G{sub max}) with distance behind the borehole wall is determined at each pressure. The results of field tests with the borehole SASW tool at two sites composed of unsaturated clayey soil are presented. These results are compared with independent field seismic measurements and with laboratory tests on intact specimens using the torsional resonant column to assess the validity of the new field method.

  8. Silica phase changes: Diagenetic agent for oil entrapment, Lost Hills field, California

    SciTech Connect (OSTI)

    Julander, D.R.; Szymanski, D.L. )

    1991-02-01

    The siliceous shales of the Monterey Group are the primary development target at Lost Hills. Silica phase changes have influenced the distribution and entrapment of hydrocarbons. With increasing temperature, opal A phase diatomite is converted to opal CT and finally quartz phase rock. All phases are low in permeability. The opal A diatomite is characteristically high in oil saturation and productive saturation. Productivity from this phase is dependent on structural position and fieldwide variations in oil viscosity and biodegradation. The deeper chert reservoir coincides with the opal CT to quartz phase transition. Porosity is again reduced in this transition, but saturations in the quartz phase rocks increase. Tests in the chert reservoir indicate a single, low-permeability system, suggesting the importance of matric contribution. resistivity and porosity in the diatomite, and resistivity and velocity in the chert, are the physical properties which best reflect saturation. Methods exploiting these properties (FMS, BHTV, borehole, and surface shear wave studies) should be helpful in further characterizing the reservoirs and identifying future pay.

  9. Simplified method to characterize municipal solid waste properties under seismic conditions

    SciTech Connect (OSTI)

    Choudhury, Deepankar Savoikar, Purnanand

    2009-02-15

    The response of municipal solid waste landfills during earthquakes is gaining worldwide attention due to the devastating nature of earthquakes on landfills. Safety code provisions and regulations of various countries require the incorporation of safety measures against seismic hazards in the design of new landfills, as well as for extensions of existing landfills in seismic zones. Determination of dynamic properties is the first step for the analysis of municipal solid waste materials under seismic conditions. Landfill composition and properties, like unit weight, shear wave velocity, shear strength, normalized shear modulus, and material damping, are the most important dynamic properties that have direct impact on the seismic behaviour of landfills, and need to be evaluated carefully. In the present study, based on the extensive data provided by various researchers, the dynamic properties of landfill materials are analyzed using curve-fitting techniques, and simple mathematical equations are proposed. The resulting profiles are compared with laboratory and field data wherever possible. These properties are difficult to generalize and may vary from landfill to landfill. Hence, the proposed simple mathematical models for these landfill properties can be used to design municipal solid waste landfills in the absence of landfill-specific field data under seismic conditions.

  10. Seismic hazard analysis at Rocky Flats Plant

    SciTech Connect (OSTI)

    McGuire, R.K.

    1993-10-01

    A probabilistic seismic hazard analysis is being conducted for the DOE Rocky Flats Plant, Jefferson County, Colorado. This is part of the overall review of the seismic exposure to facilities being conducted by DOE. The study has four major elements. (1) The historical seismicity in Colorado is being reviewed and synthesized to estimate historical rates of earthquake activity in the region of the site. (2) The geologic and tectonic evidence in Colorado and along the Front Range is being reviewed to determine appropriate seismic zones, potentially active faults, and constraints on fault slip rates. (3) Earthquake ground motion equations are being derived based on seismological knowledge of the earth`s crust. Site specific soil amplification factors are also being developed using on-site shear wave velocity measurements. (4) The probability of exceedence of various seismic ground motion levels is being calculated based on the inputs developed on tectonic sources, faults, ground motion, and soil amplification. Deterministic ground motion estimates are also being made. This study is a state-of-the-art analysis of seismic hazard. It incorporates uncertainties in the major aspects governing seismic hazard, and has a documented basis founded on solid data interpretations for the ranges of inputs used. The results will be a valid basis on which to evaluate plant structures, equipment, and components for seismic effects.

  11. Exact propagating nonlinear singular disturbances in strongly coupled dusty plasmas

    SciTech Connect (OSTI)

    Das, Amita; Tiwari, Sanat Kumar; Kaw, Predhiman; Sen, Abhijit [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2014-08-15

    The dynamical response of the strongly coupled dusty plasma medium has recently been described by utilizing the Generalized Hydrodynamic (GHD) model equations. The GHD equations capture the visco-elastic properties of the medium and have been successful in predicting a host of phenomena (e.g., existence of novel transverse shear waves in the fluid medium, modification of longitudinal wave dispersion by elastic effects, etc.) which have found experimental confirmation. In this paper, the nonlinear longitudinal response of the medium governed by GHD equations in strong coupling limit is discussed analytically. The structure of the equations rules out the balance between dispersion and nonlinearity, thereby, forbidding soliton formation. However, a host of new varieties of nonlinear solutions are found to exist, which have singular spatial profiles and yet have conservative properties. For instance, existence of novel conservative shock structures with zero strength is demonstrated, waves whose breaking produces no dissipation in the medium are observed, propagating solutions which produce cusp like singularities can exist and so on. It is suggested that simulations and experiments should look for these novel nonlinear structures in the large amplitude strong coupling limit of longitudinal disturbances in dusty plasmas.

  12. P-SV conversions at a shallow boundary beneath Campi Flegrei caldera (Italy) - evidence for the magma chamber

    SciTech Connect (OSTI)

    Ferrucci, F.; Hirn, A.; De Natale, G.; Virieux, J.; Mirabile, L. Inst. de Physique du Globe, Paris Osservatorio Vesuviano, Naples CNRS, Inst. de Geodynamique, Valbonne Ist. Universitario Navale, Naples )

    1992-10-01

    Seismograms from an active seismic experiment carried out at Campi Flegrei caldera (near Naples, Italy), show a large-amplitude SV-polarized shear wave, following by less than 1.5-s P waves reflected at wide angle from a deep crustal interface. Early arriving SV-polarized waves, with the same delay to direct P waves, are also observed in seismograms from a regional 280 km-deep, magnitude 5.1 earthquake. Such short delays of S to P waves are consistent with a P-SV conversion on transmission occurring at a shallow boundary beneath the receivers. The large amplitude of the converted-SV phase, along with that the P waves are near vertical, requires a boundary separating a very low rigidity layer from the upper caldera fill. The converted phases are interpreted as a seismic marker of a magma chamber. The top of this magma chamber is located slightly deeper than the deepest earthquakes observed during the 1982-1984 unrest of Campi Flegrei. 8 refs.

  13. Single crystal neutron diffraction study of lattice and magnetic structures of 5M modulated Ni2Mn1.14Ga0.86

    SciTech Connect (OSTI)

    Pramanick, Abhijit; Wang, Xiaoping; An, Ke; Stoica, Alexandru Dan; Hoffmann, Christina; Wang, Xun-Li

    2012-01-01

    A comprehensive description of the crystal and magnetic structures of Ni-Mn-Ga magnetic shape memory alloys is important to understand the physical origins of their magnetoelastic properties. These structural details for an off-stoichiometric Ni2Mn1.14Ga0.86 alloy have been obtained from refinement of high-resolution single crystal neutron diffraction data following a (3+1)-dimensional superspace formalism. In particular, the structure adopts a P2/m( 0 )00 (3+1)-D superspace symmetry with the following fundamental lattice parameters: a=4.255(4) , b=5.613(4) , c=4.216(3) , a commensurate periodicity of 5M and a modulation wave vector of . The magnetic moments are aligned along the b-axis. The modulations for atomic site displacements, site occupancies and magnetic moments are elucidated from a (3+1)-D refinement of the neutron diffraction data. In addition to atomic displacements corresponding to shear waves along <110>, distortions of Ni-centric tetrahedra are also evident. Physical interpretations for the different structural distortions and their relationship with magnetic properties are discussed.

  14. THE ROLE OF SUPERLUMINAL ELECTROMAGNETIC WAVES IN PULSAR WIND TERMINATION SHOCKS

    SciTech Connect (OSTI)

    Amano, Takanobu; Kirk, John G.

    2013-06-10

    The dynamics of a standing shock front in a Poynting-flux-dominated relativistic flow is investigated by using a one-dimensional, relativistic, two-fluid simulation. An upstream flow containing a circularly polarized, sinusoidal magnetic shear wave is considered, mimicking a wave driven by an obliquely rotating pulsar. It is demonstrated that this wave is converted into large-amplitude electromagnetic waves with superluminal phase speeds by interacting with the shock when the shock-frame frequency of the wave exceeds the proper plasma frequency. The superluminal waves propagate in the upstream, modify the shock structure substantially, and form a well-developed precursor region ahead of a subshock. Dissipation of Poynting flux occurs in the precursor as well as in the downstream region through a parametric instability driven by the superluminal waves. The Poynting flux remaining in the downstream region is carried entirely by the superluminal waves. The downstream plasma is therefore an essentially unmagnetized, relativistically hot plasma with a non-relativistic flow speed, as suggested by observations of pulsar wind nebulae.

  15. Increasing Waterflood Reserves in the Wilmington Oil Field Through Improved Reservoir Characterization and Reservoir Management.

    SciTech Connect (OSTI)

    Koerner, R.; Clarke, D.; Walker, S.; Phillips, C.; Nguyen, J.; Moos, D.; Tagbor, K.

    1997-10-21

    The objectives of this quarterly report are to summarize the work conducted under each task during the reporting period July - September 1997 and to report all technical data and findings as specified in the `Federal Assistance Reporting Checklist`. The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology. The identification of the sands with high remaining oil saturation will be accomplished by developing a deterministic three dimensional (3-D) geologic model and by using a state of the art reservoir management computer software. The wells identified by the geologic and reservoir engineering work as having the best potential will be logged with a pulsed acoustic cased-hole logging tool. The application of the logging tools will be optimized in the lab by developing a rock-log model. This rock-log model will allow us to convert shear wave velocity measured through casing into effective porosity and hydrocarbon saturation. The wells that are shown to have the best oil production potential will be recompleted. The recompletions will be optimized by evaluating short radius and ultra-short radius lateral recompletions as well as other techniques.

  16. Increasing Waterflood Reserves in the Wilmington Oil Field Through Improved Reservoir Characterization and Reservoir Management.

    SciTech Connect (OSTI)

    Koerner, Roy; Clarke, Don; Walker, Scott; Phillips, Chris; Nauyen, John; Moos, Dan; Tagbor, Kwasi

    1997-07-28

    The objectives of this quarterly report are to summarize the work conducted under each task during the reporting period April - June 1997 and to report all technical data and findings as specified in the `Federal Assistance Reporting Checklist`. The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology. The identification of the sands with high remaining oil saturation will be accomplished by developing a deterministic three dimensional (3-D) geologic model and by using a state of the art reservoir management computer software. The wells identified by the geologic and reservoir engineering work as having the best potential will be logged with a pulsed acoustic cased-hole logging tool. The application of the logging tools will be optimized in the lab by developing a rock-log model. This rock-log model will allow us to convert shear wave velocity measured through casing into effective porosity and hydrocarbon saturation. The wells that are shown to have the best oil production potential will be recompleted. The recompletions will be optimized by evaluating short radius and ultra-short radius lateral recompletions as well as other techniques.

  17. Increasing waterflood reserves in the Wilmington oil field through improved reservoir characterization and reservoir management. [Quarterly report], October 1, 1995--December 31, 1995

    SciTech Connect (OSTI)

    Sullivan, D.; Clarke, D.; Walker, S.; Phillips, C.; Nguyen, J.; Moos, D.; Tagbor, K.

    1996-01-23

    The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology. The identification of the sands with high remaining oil saturation will be accomplished by developing a deterministic three dimensional (3-D) geologic model and by using a state of the art reservoir management computer software. The wells identified by the geologic and reservoir engineering work as having the best potential will be logged with a pulsed acoustic cased-hole logging tool. The application of the logging tools will be optimized in the lab by developing a rock-log model. This rock-log model will allow us to convert shear wave velocity measured through casing into effective porosity and hydrocarbon saturation. The wells that are shown to have the best oil production potential will be recompleted. The recompletions will be optimized by evaluating short radius and ultra-short radius lateral recompletions as well as other techniques. Technical progress is reported for the following tasks; reservoir characterization, reservoir engineering; deterministic (3-D) geologic modeling; pulsed acoustic logging; and technology transfer.

  18. Stress-dependent recovery of point defects in deformed aluminum: An acoustic-damping study

    SciTech Connect (OSTI)

    Ogi, H.; Tsujimoto, A.; Hirao, M.; Ledbetter, H.

    1999-10-26

    The stress dependence of point-defect diffusion to dislocations in a 99.99% polycrystalline aluminum was studied using shear-wave attenuation and phase velocity. By holding the stress after deformation, attenuation and velocity approach their nonstressed values. The holding stress was varied between 0 and 12 MPa, after applying a 15 MPa compressive stress. Time-independent attenuation and stress-induced velocity change were introduced into the Granato-Hikata-Luecke theory, which first established the change of attenuation and velocity caused by the point-defect diffusion to dislocations. Good agreement was found between measurements and the modified theory. The stress dependence of the recovery rate was interpreted as a reduction of the migration energy of point defects diffusing to dislocations, and the activation volume was calculated for uniaxial stress. Electromagnetic acoustic resonance (EMAR) was used for the measurements. Being noncontact and highly sensitive, EMAR permitted detailed measurement of the attenuation and velocity evolutions during the unloading-holding stress sequence.

  19. Mechanical properties of Municipal Solid Waste by SDMT

    SciTech Connect (OSTI)

    Castelli, Francesco; Maugeri, Michele

    2014-02-15

    Highlights: The adoption of the SDMT for the measurements of MSW properties is proposed. A comparison between SDMT results and laboratory tests was carried out. A good reliability has been found in deriving waste properties by SDMT. Results seems to be promising for the friction angle and Youngs modulus evaluation. - Abstract: In the paper the results of a geotechnical investigation carried on Municipal Solid Waste (MSW) materials retrieved from the Cozzo Vuturo landfill in the Enna area (Sicily, Italy) are reported and analyzed. Mechanical properties were determined both by in situ and laboratory large-scale one dimensional compression tests. While among in situ tests, Dilatomer Marchetti Tests (DMT) is used widely in measuring soil properties, the adoption of the DMT for the measurements of MSW properties has not often been documented in literature. To validate its applicability for the estimation of MSW properties, a comparison between the seismic dilatometer (SDMT) results and the waste properties evaluated by laboratory tests was carried out. Parameters for fresh and degraded waste have been evaluated. These preliminary results seems to be promising as concerns the assessment of the friction angle of waste and the evaluation of the S-wave in terms of shear wave velocity. Further studies are certainly required to obtain more representative values of the elastic parameters according to the SDMT measurements.

  20. Processing ultrasonic inspection data from multiple scan patterns for turbine rotor weld build-up evaluations

    SciTech Connect (OSTI)

    Guan, Xuefei; Zhou, S. Kevin; Rasselkorde, El Mahjoub; Abbasi, Waheed

    2015-03-31

    The study presents a data processing methodology for weld build-up using multiple scan patterns. To achieve an overall high probability of detection for flaws with different orientations, an inspection procedure with three different scan patterns is proposed. The three scan patterns are radial-tangential longitude wave pattern, axial-radial longitude wave pattern, and tangential shear wave pattern. Scientific fusion of the inspection data is implemented using volume reconstruction techniques. The idea is to perform spatial domain forward data mapping for all sampling points. A conservative scheme is employed to handle the case that multiple sampling points are mapped to one grid location. The scheme assigns the maximum value for the grid location to retain the largest equivalent reflector size for the location. The methodology is demonstrated and validated using a realistic ring of weld build-up. Tungsten balls and bars are embedded to the weld build-up during manufacturing process to represent natural flaws. Flat bottomed holes and side drilled holes are installed as artificial flaws. Automatic flaw identification and extraction are demonstrated. Results indicate the inspection procedure with multiple scan patterns can identify all the artificial and natural flaws.